Title of Invention	A 4 CYCLE ENGINE STARTING SYSTEM
Abstract	An engine starting system is to be provided wherein a noise generated at the time of starting an engine is suppressed low. An engine starting system for driving a starting motor in response to an engine starting operation, comprising start signal generating means 401-406 for generating a start signal corresponding to the period of the starting a start signal extending means 407 for extending a start signal sin shorter than a predetermined reference time to the reference time or linger and outputting thus-extended signal, and a starter relay 162 which drives the starting motor in accordance with an output signal provided from the start signal extending means 407.

Title of Invention

A 4 CYCLE ENGINE STARTING SYSTEM

Abstract

An engine starting system is to be provided wherein a noise generated at the time of starting an engine is suppressed low. An engine starting system for driving a starting motor in response to an engine starting operation, comprising start signal generating means 401-406 for generating a start signal corresponding to the period of the starting a start signal extending means 407 for extending a start signal sin shorter than a predetermined reference time to the reference time or linger and outputting thus-extended signal, and a starter relay 162 which drives the starting motor in accordance with an output signal provided from the start signal extending means 407.

Full Text	FORM 2 THE PATENTS ACT 1970 [39 OF 1970] & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION [See Section 10; rule 13] "A 4 CYCLE ENGINE STARTING SYSTEM" HONDA GIKEN KOGYO KABUSHIKI KAISHA, a corporation of Japan, 1-1, Minamiaoyama 2-chome, Minato-ku, Tokyo, Japan The following specification particularly describes the nature o the invention and the manner in which it is to be performed:- The present invention relates to a 4 cycle engine starting system. [Detailed Description of the Invention] [0001] [Technical Field of the Invention] The present invention relates to an engine starting system for starting an engine with use of a starting motor and more particularly to an engine starting system suitable for a vehicle adopting an automatic stop/start system which stops an engine automatically in response to predetermined stop conditions during travel of the vehicle and which, after the stop, restarts the engine in response to a predetermined starting operation. [0002] [Prior Art] For suppressing noise generated at the time of starting an engine there have been proposed various techniques, including the technique disclosed in Japanese Unexamined Patent Publication No. Hei 11-30139 for example. [0003] [Problem to be Solved by the Invention] At the time of starting an engine, if the time of a starting operation performed by the driver of a vehicle is short and hence a starting motor is driven for only an extremely short time, the starting motor will stop before a piston exceeds a top dead center just after explosion and an explosion load will act in a reversing direction, with consequent occurrence of a crank shaft reversing phenomenon, i.e., what is called kick-back, and occurrence of knocking noise or gear noise. [0004] It is an object of the present invention to solve the above-mentioned problem of the prior art and provide an engine starting system capable of keeping low the engine starting noise. [0005] [Means for Solving the Problem] According to the present invention, for achieving the above-mentioned object, there is provided an engine starting system wherein a starting motor is driven in response to an engine starting operation, the engine starting system including a start signal generating means which generates a start signal corresponding to the period of the starting operation, a start signal extending means which extends a start signal shorter than a predetermined reference time to the predetermined reference 3 time or longer and outputs the thus - extended signal, and a drive means which drives the starting motor in accordance with an output signal provided from the start signal extending means. [0 006] According to the above feature, even when the starting operation for driving the starting motor is performed for only a short time, it is possible to let the starting motor operate for the reference time or longer. Therefore, it is possible to prevent the occurrence of kick-back at the time of starting an engine due to a short driving time of the starting motor and hence possible to reduce the engine starting noise. 4 automatic engine stop/start system; Fig. 4 is a sectional view of a swing unit according to a third embodiment of the present invention equipped with an automatic engine stop/start system; Fig. 5 is a side view of a motorcycle with an automatic engine stop/start system mounted thereon; Fig. 6 is a sectional view of a swing unit according to a fourth embodiment of the present invention equipped with an automatic engine stop/start system; Fig. 7 is a sectional view of the swing unit of the fourth embodiment taken along a plane perpendicular to the crank shaft; Fig. 8 is a block diagram of an automatic engine stop/start system embodying the present invention; Fig. 9 is a block diagram (No.l) showing functions of a main control system; Fig. 10 is a block diagram (No.2) showing functions of the main control system; Fig. 11 is a block diagram (No.3) showing functions of the main control system; Fig. 12 is a block diagram (No.4) showing functions of the main control system; Fig. 13 is a table (No.l) showing principal operations of the main control system; Fig. 14 is a table (No.2) showing principal operations of the main control system; Fig. 15 is a diagram showing conditions for operation mode switching; Fig. 16 is a diagram showing a relation of engine speed [0007] [Mode for Carrying Out the Invention] The present invention will now be described in detail with reference to the drawings. Fig. 5 is an entire side view of a motorcycle with an engine stop/start control system according to the present invention mounted thereon. A front portion 2 of a vehicle body and a rear portion 3 of the vehicle body are connected together through a low floor portion 4 and a framework of the vehicle body is constituted by a body frame which includes a down-tube 6 and a main pipe 7. A fuel tank and a receptacle box (neither shown) are supported by a main pipe 7 and a seat 8 is disposed thereon. The seat 8 can also serve as a lid of a luggage box which underlies the seat. The luggage box is constituted so that it can be opened and closed by a hinge mechanism provided in a front portion FR of the box. [0008] In the front portion 2 of the vehicle body, a steering head 5 is secured to the down-tube 6 and a front fork 12A is pivotally supported by the steering head 5. A handle 11A is attached to an upper end of the front fork 12A, while a front wheel 13A is connected to a lower end of the front fork through an axle. The handle 11A is covered from above with a handle cover 33 which also serves as an instrument panel. [0009] At an intermediate position of the main pipe 7 is supported a link member (hanger) 37 pivotably and a swing unit 17 is connected to the main pipe 7 pivotably through the hanger 37. A single-cylinder 4-cycle engine 200 is mounted to a front portion of the swing unit 17 . A belt type continuously variable transmission 35 is constituted so as to extend backward from the engine 200. At a rear portion of the transmission 35 is mounted a reduction mechanism 38 through a centrifugal clutch and a rear wheel 21 is connected to the reduction mechanism 38 through an axle. A rear cushion 22 is interposed between an upper end of the reduction mechanism 38 and an upper bent portion of the main pipe 7. [0010] An intake pipe 23 extending from a cylinder head 32 of the engine 200 is connected to the front portion of the swing unit 17. Further, a carburetor 24 and an air cleaner 25 connected to the carburetor are disposed in the intake pipe 23. A pivot shaft 18 is mounted at a lower portion of a swing unit case 31 and a main stand 26 is pivotally connected to the pivot shaft 18. For parking, the main stand 26 is brought upright (indicated with a chain line). 9 [0011] Fig. 1 is a sectional view of the swing unit 17 according to a first embodiment of the present invention, which corresponds to a sectional structure taken along line A-A in Fig. 5, and Fig. 2 is a sectional view of the swing unit 17 taken along a plane perpendicular to a crank shaft. The swing unit 17 is provided with an engine 200 disposed in a front position of a vehicle, a power generating section G connected to one end of a crank shaft 12 , and a driving section ATI and a driven section AT2 of an automatic transmission connected to the opposite end of the crank shaft 12. [0012] In a swing unit case 31 is mounted the crank shaft 12 which is supported rotatably by main bearings 10 and 11. A connecting rod 14 is connected to the crank shaft 12 through a crank pin 13. A generator 44 is mounted on one end of the crank shaft 12 overhanging from a crank chamber 9. [0013] One (crank shaft-side) sleeve 57a of a one-way clutch 50 is fixed with screw 43 to an outer rotor 42 of the generator 44, while the other (sprocket-side) sleeve 55a is rotatably supported integrally with a sprocket 58 by the crank shaft 12 at a position between the generator 44 and the main bearing 11. On the sprocket 58 is entrained a chain 40 for obtaining a starting torque from a starting motor 49 shown in Fig. 2. [0014] A clutch portion 56a of the one-way clutch 50 prevents the outer rotor 42 of the generator 44, i.e., crank shaft 12, from idling in a reverse direction relatively with respect to the sprocket 58 and permits the crank shaft from idling in a forward direction. Therefore, when the starting motor 49 is operated at the time of starting the engine and the sprocket 58 is rotated in the forward direction of the crank shaft 12, the crank shaft also rotates in the forward direction following the rotation of the sprocket. [0015] After start-up of the engine, the crank shaft idles with respect to the sprocket 58 even if the starting motor 49 turns OFF and therefore the driving force of the crank shaft 12 is not transmitted to the starting motor 49. [0016] A sprocket 59 is fixed onto the crank shaft 12 at a position between the sprocket 58 and the main bearing 11. A chain 60 is entrained on the sprocket 59 to obtain power for driving a cam shaft 69 from the crank shaft 12. The sprocket 59 is formed integrally with a gear 61 which is for transmitting power to a lubricating oil circulating pump (not shown). [0017] A piston 63 disposed within a cylinder 62 is connected to a small end side of a connecting rod 14. A spark plug 65 is threadedly engaged with a cylinder head 32 so that an electrode portion thereof faces a combustion chamber formed between the head of the piston 63 and the cylinder head 32 . The cylinder 62 is surrounded by a water jacket 66. [0018] The cam shaft 69 is supported rotatably within the 11 cylinder head 32 and above the cylinder 62, with a cam sprocket 72 being fixed onto the cam shaft 69. The chain 60 is entrained on the cam sprocket 72 to transmit rotation of the sprocket 59, i.e., rotation of the crank shaft 12, to the cam shaft 69. [0019] A rocker arms 73 is disposed on the cam shaft 69. As the cam shaft 69 rotates, the rocker arm 73 swings in accordance with the cam shape of the cam shaft. The cam shape of the cam shaft 69 is determined so that intake and exhaust valves 95 and 96 are opened and closed according to strokes of the four-cycle engine. [0020] A pulley 83, on which a V belt 82 is to be entrained, is mounted on an end portion of the crank shaft 12 on the side opposite to the side where the generator 44 is disposed. The pulley 83 comprises a fixed pulley piece 83a whose movements in both rotational and axial directions are fixed with respect to the crank shaft 12 and a movable pulley 83b which is slidable in the axial direction with respect to the crank shaft. A holder plate 84 is attached to a rear side, i.e., the side not abutted against the V belt, of the movable pulley piece 83b. The holder plate 84 is adapted to rotate integrally with the crank shaft 12 while its movements in both rotational and axial directions are inhibited. The space surrounded by both holder plate 84 and movable pulley piece 83b forms a pocket which receives therein a roller 85 serving as a governor weight. [0021] A fan 83c is integrally formed on a rear side, i.e., the 12 side not abutted against the Vbelt 82, of the fixed pulley piece 83a and an air cleaner governor 70 provided with an air cleaner 71 for cleaning and introducing cooling air into an automatic transmission chamber is applied to an opening of the swing unit case 31 opposed to the fan 83c. The fan 83c is formed so as to suck the outside air into the automatic transmission chamber through the air cleaner 71 upon forward rotation of the crank shaft 12. [0022] In the driven section A2 of the automatic transmission, a fixed pulley piece 132a of a pulley 132 is mounted on a main shaft 125 of a clutch. A cup-like clutch disc 134 is fixed onto an end portion of the main shaft 125 with use of a nut 133. A movable pulley piece 132b of the pulley 132 is mounted on a sleeve 135 of the fixed pulley piece 132a so as to be slidable in the longitudinal direction of the main shaft 125. The movable pulley piece 132b is engaged withadisc 136 soas tobe integrally rotatable around the main shaft 125. Between the disc 136 and the movable pulley piece 132b is mounted a compression spring 137 having a repulsive force acting in a direction to expand the distance between the two. The main shaft 125, an idle shaft 142 and an output shaft 145 are engaged with one another and a rim 21a of a rear wheel 21 is fixed to the output shaft 145. [0023] In this embodiment, as described above, since the starting motor 49 and the crank shaft 12 are connected together through a chain 40 as an endless connecting means and the crank shaft 12 is driven by the chain at the time of start-up of the engine, 13 ^ the starting noise caused by the starting motor can be kept lower than in the prior art. [0024] In the case where the generator 44 and the pulley 83 of the automatic transmission are disposed respectively on both ends of the crank shaft 12 with the crank chamber 9 therebetween as in this embodiment, the pulley 83 occupies a larger axial area on the crank shaft than the generator 44. Thus, also as to the crank shaft lengths on both sides of the crank chamber 9, the pulley 83 side tends to be longer than the generator 44 side. In this embodiment, however, since the sprocket 58 and the one-way clutch 50 thereof are provided on the generator 44 side, the crank shaft lengths on both sides of the crank chamber 9 can be made equal to each other and thus can be stabilized in their rotational balance. [0025] According to this embodiment, moreover, the chain 40 for connecting the crank shaft 12 and the starting motor 49 and the chain 60 for connecting the crank shaft 12 and the cam shaft 69 can be gathered on one side of the engine, so that the maintainability is improved. [0026] A description will now be given of an automatic engine stop/start system to which the present invention is applied. This system has an operation mode (hereinafter referred to as the "start & idle switch (SW) mode" which permits idling and an operation mode ("stop/start mode" hereinafter) which restricts (or inhibits) idling. 14 [0027] In the "start & idle switch (SW) mode", idling is permitted temporarily upon initial start-up of the engine after turning ON of a main power supply for the purpose of warming-up at the time of starting the engine. Even when the engine condition is not after initial start-up thereof, idling is permitted by the driver's will (turning ON the idle SW). [0028] On the other hand, in the "stop/start mode" in which idling is restricted, the engine stops automatically when the vehicle is stopped, and if an accelerator pedal is operated with engine OFF, the engine is restarted automatically, making it possible to start the vehicle. [0029] Fig. 8 is a block diagram showing an entire configuration of the automatic engine stop/start system in the engine 200, in which the same reference numerals as above represent the same or equivalent portions. [0030] A generator (AC generator 172) is mounted on the crank shaft 12 coaxially and electric power generated by the generator 172 is charged into a battery 168 through a regulator rectifier 167. The regulator rectifier 167 controls an output voltage of the generator 172 to 12V to 14.5V. The battery 168 supplies a driving current to a starter motor 171 when a starter relay 162 is energized and further supplies a load current to various general electric appliances 174 and a main control system 160 through a main switch 173. [0031] To the main control system 160 are connected an Ne sensor 153 for detecting the number of revolutions of the engine, or engine speed, Ne, an idle switch 253 for permitting or restricting idling of the engine 200 manually, a sitting switch 254 which, upon sitting of the driver on a driver seat, closes a contact and outputs "H" level, a vehicle speed sensor 255 for detecting the vehicle speed, a stand-by indicator 256 which flickers in the "stop/start mode", a throttle sensor 257 (including a throttle switch 257a) for detecting a throttle opening 9 , a starter switch 258 for driving the starter motor 171 to start the engine 200, a stop switch 259 which outputs "H" level in response to a braking operation, a battery indicator 276 which goes ON upon drop in voltage of the battery 168 to below a predetermined value (for example, 10V) and warns the driver of insufficient charging, and a water temperature sensor 251 for detecting the temperature of engine cooling water. [0032] Further connected to the main control system 160 are an ignition controller (including an ignition coil) 161 which causes the spark plug 65 to ignite in synchronism with rotation of the crank shaft 12, a control terminal of the starter relay 162 which supplies electric power to the starter motor 171, a control terminal of a headlight driver 163 which supplies electric power to a headlight 169, and a control terminal of a bistarter relay 164 which supplies electric power to a bistarter 165 mounted to a carburetor 166 . The headlight driver 163 is constituted by a switching element such as a FET and adopts 16 what is called chopping control in which the switching element is turned on and off at predetermined cycle and duty ratio to substantially control the voltage to be applied to the headlight 169. [0033] Figs. 9 to 12 are block diagrams (No. 1, No . 2 , No . 3 , No. 4) , in which the same reference numerals as in Fig.8 represent the same or equivalent portions. [0034] Figs. 13 and 14 tabulate control contents of components of the main control system which components are a starter relay control section 400, a bistarter control section 900, a stand-by indicator control section 600, a headlight control section 800, an after-stop non-sitting control section 100, an ignition control section 700, an ignition knock control section 200, and a charging control section 500. [0035] In Fig. 9, when the state of the idle switch 253 and that of the vehicle satisfy predetermined conditions, an operation switching section 300 switches the operation mode of the main control system 160 to either "start & idle SW mode" or "stop/start mode." [0036] A state signal from the idle switch 253 is inputted to an operation mode signal output unit 301 in the operation switching section 300. The state signal from the idle switch 253 indicates "L" level when it is OFF (idling restriction) and "H" level when it is ON (idling permission). In response to 17 output signals provided from the idle switch 253, vehicle speed sensor 255 and water temperature sensor 155 the operation mode signal output unit 301 outputs an operation mode signal S301 which specifies the operation mode of the main control system 160 to either "start & idle SW mode" or "stop/start mode." [0037] Fig. 15 schematically illustrates operation mode switching conditions adopted in the operation mode signal output unit 301. When the main switch 173 is turned ON to reset the main control system 160 (condition 1 is established), the operation mode signal S301 is set to "L" level to start the "start & idle SW mode." [0038] In the "start & idle SW mode", if a vehicle speed not lower than a predetermined speed (for example, 10 km/hr), the water temperature is not lower than a predetermined temperature (for example, a temperature high enough to predict completed warming-up) and the idle switch 253 is OFF (condition 2 is established), the operation mode signal S301 is switched from "L" to "H" level to start the "stop/start mode." [0039] In the "stop/start mode", if the idle switch SW is turned from OFF to ON (condition 3 is established) , the operation mode signal S301 is switched from "H" to "L" level to return the operation mode from "stop/start mode" to "start & idle SW mode. " In both "stop/start mode" and "start & idle SW mode", an OFF state is established once the main SW 173 is turned OFF (condition 4 is established). 18 [0040] Turning back to Fig. 9, the starter relay control section 400 starts up the starter relay 162 in accordance with each of the above operation modes and under predetermined conditions. A detection signal provided from the Ne sensor 153 is inputted to both a below-cranking- revolutions determining unit 401 and a below-idling-revolutions determining unit 407. When the engine speed corresponds to predetermined cranking revolutions (for example, 600 rpm) or lower, the below-cranking-revolutions determining unit 401 outputs an "H" level signal. Likewise, when the engine speed corresponds to predetermined idling revolutions (for example, 1200 rpm), the below-idling-revolutions determining unit 407 outputs an "H" level signal. [0041] An AND circuit 402 outputs an AND of the output signal provided from the below- cranking- revolutions determining unit 401, a state signal from the stop switch 259 and a state signal from the starter switch 258. The AND circuit 404 outputs an AND of the output signal provided from the below- idling-revolutions determining unit 407, a detection signal from the throttle switch 257a and a state signal from the sitting switch 254. [0042] An AND circuit 403 outputs an AND of the output signal provided from the AND circuit 402 and the inversion of the operation mode signal S301. An AND circuit 405 outputs an AND of the output signal provided from the AND circuit 404 and the 19 operation mode signal S301. An OR circuit 406 ORs the output signals of the AND circuits 403 and 405 with each other and outputs the OR as a start signal Sin. If the pulse width of the start signal Sin is shorter than a predetermined reference time, a start signal extending unit 407 extends the pulse width to a width not shorter than the reference time and outputs the thus pulse width extended signal to the starter relay 162. [0043] The start signal extending unit 407 includes a multivibrator 407a which detects the start signal Sin and outputs a one-shot pulse signal and an OR circuit 407b which ORs the start signal Sin with the output signal of the multivibrator 407a and outputs the OR as a start signal Sout after extension. The multivibrator 407a can extend the pulse width of its output pulse as desired according to the resistance value of a variable resistor. [0044] Fig. 18 is a timing chart showing the operation of the start signal extending unit 407. A variable resistance value of the multivibrator 407a is set so as to give an output pulse width of 0 . 6 second irrespective of the pulse width ton of the start signal Sin. Therefore, even when the starter switch 258 is turned ON for only a shorter period than 0.6 seconds, the output pulse width of the multivibrator 4 07a becomes 0 . 6 second. [0045] Further, since the OR circuit 407b outputs an OR of the output pulse from the multivibrator 407a and the start signal Sin, the output signal Sout from the start signal extending unit 20 407 comes to have a pulse width of 0 . 6 seconds if the pulse width ton of the start signal Sout is shorter than 0.6 seconds, while if the pulse width ton of the start signal Sin is longer than 0.6 seconds, the output signal Sout comes to have the same pulse width. [0046] Although in the above embodiment the start signal is extended up to 0.6 second, the present invention is not limited thereto, but it is necessary to set an optimum pulse width in accordance with the rotational speed of the starting motor 49 and the reduction ratio. [0047] More specifically, as shown in Fig. 19, when the engine is stopped, it is very likely that the piston will stop in the compression stroke just before reaching the top dead center (TDC) in explosion. Then, in the next engine starting operation, if the starting motor 49 is driven from this state, the engine does not ignite just before TDC in explosion which immediately follows, but ignites only just before the next TDC in explosion. Thus, the starting motor 49 is required to rotate the engine so that the piston reaches at least the next TDC in explosion which follows the just-after TDC. [0048] However, if the starting motor 49 stops at the time when the piston has reached near the next TDC in explosion which follows the just-after TDC, an explosion load will be exerted in the reversing direction and there occurs what is called kick-back, i.e., reverse rotation of the crank shaft 12. 21 Therefore, it is desirable that the extension time by the start signal extending unit 407 be set to the time required for the piston which has stopped just before TDC in explosion to be driven up to a position exceeding TDC in compression which immediately follows the TDC in explosion and the next TDC in compression. [0049] In this embodiment, as described above, the start signal extending unit 407 is provided, whereby the starter 171 is driven for at least 0 . 6 second even when the starter switch 258 is turned ON for only a shorter period than 0.6 second. Consequently, the occurrence of kick-back at the time of start-up of the engine is prevented and it becomes possible to reduce the engine starting noise. [0050] According to this embodiment, moreover, even by opening a throttle grip for only a short time it is possible to let the starting motor operate for the minimum time necessary to start the engine. Therefore, particularly in a vehicle which adopts an automatic centrifugal clutch, the driver can start the engine by an easy throttle operation without paying attention to a rise of the engine speed. [0051] According to the above starter relay control, the AND circuit 403 is enabled in the "start & idle switch mode." Therefore, if the starter switch 258 is turned ON by the driver (if the output of the AND circuit 402 goes "H") when the engine speed is below cranking revolutions and with the stop switch 259 ON (during braking operation), the starter relay turns conductive and the starter motor 171 is turned ON. [0052] In the "stop/start mode" the AND circuit 405 is enabled. Therefore, if the throttle valve is opened (if the output of the AND circuit 404 goes "H") when the engine speed is below idling speed and with the sitting switch 254 ON (the driver is sitting on the seat), the starter relay 162 turns conductive and the starter motor 171 is turned ON. [0053] In the stand-by indicator control section 600 shown in Fig. 10, a detection signal from the vehicle speed sensor 255 is inputted to a vehicle- speed- zero determining unit 601, which in turn outputs an "H" level signal if the vehicle speed is substantially zero. A detection signal from the Ne sensor 153 is inputted to an Ne determining unit 602, which in turn outputs an "H" level signal if the engine speed is below a predetermined value. An AND circuit 603 outputs an AND of the output signals provided from the determining units 601 and 602. [0054] An AND circuit 604 ANDs the output signal of the AND circuit 603 with an inverted signal from the sitting switch 254 and outputs the AND. Likewise, an AND circuit 605 outputs an AND of the output signal of the AND circuit 603 and the output of the sitting switch 254. A lighting/blinking control unit 606 produces a lighting signal if the output signal from the AND circuit 604 is "H" level and produces a blinking signal if the output signal from the AND circuit 604 is "L" level. An AND 23 circuit 607 outputs an AND of the output signal from the lighting/blinking control unit 606 and the operation mode signal S301. The stand-by indicator 256 lights in response to the lighting signal and blinks in response to the blinking signal. [0055] According to such a stand-by indicator control, as shown in Fig. 13, the stand-by indicator 256 lights if the driver does not sit on the seat and blinks if the driver sits on the seat during stop of the vehicle in the "stop/start mode . " Therefore, if the stand-by indicator blinks, the driver can become aware that the vehicle can start running if only the accelerator grip is opened even if the engine is OFF. [0056] An ignition control section 700 in Fig. 10 permits or inhibits the igniting operation by the ignition controller 161 under predetermined conditions for each operation mode. [0057] In accordance with a detection signal provided from the vehicle speed sensor 255 a travel determining unit 701 determines whether the vehicle is traveling or not and outputs an "H" level signal if the vehicle is traveling. An OR circuit 706 outputs an OR of the output signal from the travel determining unit 701 and the output signal from the throttle switch 257a. An AND circuit outputs an AND between the output signal from the sitting switch 254 and the output signal from the OR circuit 706. Therefore, the output from the AND circuit 707 goes "H" when the throttle valve is open or when the vehicle speed is higher than zero and the driver sits on the seat. 24 [0058] An AND circuit 702 outputs an AND of the output signal from the sitting switch 254 and inverted signals from the travel determining unit 701 and the throttle switch 257a. A timer 703 delays an input signal by a predetermined time (3 seconds in this embodiment) and outputs the delayed signal. A NAND circuit 705 provides an inverted output of an AND between the output signal from the AND circuit 702 and the output signal from the timer 703. Thus, the output of the NAND circuit 705 goes "L" when the throttle valve is closed and when the vehicle speed is zero and the driver sits on the seat. [0059] While the ignition controller 161 is in its igniting operation, a movable contact of a switching circuit 708 is switched to the NAND circuit 705 side, while it is switched to the AND circuit 707 side when the ignition controller 161 is OFF. An OR circuit 709 ORs the inversion of the operation mode signal S301 with the inversion of the output from the switching circuit 708 and outputs the OR to the ignition controller 161. [0060] According to the ignition control section 700 constructed as above, as shown in Fig. 14, in the "start & idle SW mode" the output of the OR circuit 709 is always "H" level and therefore the ignition control is permitted at all times. [0061] In contrast therewith, in the "stop/start mode" , when the vehicle stops and the engine is turned OFF automatically, the ignition control is permitted if the driver sits on the seat 25 and the throttle valve is open or if the vehicle speed is higher than zero. On the other hand, when the vehicle comes to stop from its running state and if it is detected that the driver has sat on the seat, the ignition control is inhibited and the engine is turned OFF automatically. But if the driver's sitting on the seat is not detected, the ignition control continues to be permitted, so that the engine is not turned OFF automatically. [0062] Therefore, if it is impossible to detect the driver's sitting on the seat due to some trouble of the sitting switch 254, the engine is not turned OFF automatically even when the vehicle comes to stop from its running condition, thus eliminating the need of starting the engine at the time of starting the vehicle. Thus, even if there should occur any trouble of the sitting switch 254 in the system which permits automatic engine starting on condition that the driver sits on the seat, there is no fear that the travel of the vehicle may be impeded. [0063] Further, according to this embodiment, even if the driver's sitting on the seat is detected when the vehicle comes to a stop from its running condition, the ignition control is not immediately inhibited, but is inhibited after the lapse of a predetermined time (3 seconds in this embodiment). Consequently, when the vehicle stops at an intersection or at the time of U-turn in a condition such that the driver sits on the seat and the vehicle speed is nearly zero, with the throttle 26 valve being substantially closed fully, it becomes possible let the engine continue to start. [0064] The ignition knock control section 200, for each of the operation modes described above, retards the ignition timing in acceleration as compared with that in normal driving to prevent the occurrence of knocking. Particularly in this embodiment, the retard amount in starting acceleration for acceleration from an engine OFF condition is set larger than that in normal,acceleration for acceleration from an engine rotating state, whereby the occurrence of knocking in starting acceleration, which is peculiar to a vehicle equipped with an automatic engine stop/start system, is prevented completely. [0065] In a standard ignition timing determining unit 207 there is registered a standard ignition timing as an advance angle (deg) from TDC (top dead center in explosion) and as a function of engine speed Ne and throttle opening 9 . Fig. 16 illustrates the engine speed Ne and throttle opening 9 vs. standard ignition timing in this embodiment. As shown in the same figure, the ignition timing set at 15° (deg; advance angle) until the engine speed reaches 2500 rpm, and as the engine speed Ne exceeds 2500 rpm, the amount of advance amount is increased little by little. [0066] An Ne determining unit 201 sets a normal acceleration signal Saccl to "H" level if the engine speed Ne is 700 rpm --27 to "H" level if the engine speed is 700 rpm [0067] When a variation rate A 6 of the throttle opening 9 detected by the throttle sensor 257 exceeds a predetermined value, an acceleration determining unit 205 judges that an accelerating operation has been done and outputs an acceleration detection signal of "H" level. A water temperature determining unit 206 determines the temperature of cooling water on the basis of a detection signal provided from the water temperature sensor 155 and outputs an "H" level signal when the water temperature exceeds a predetermined temperature (50°C in this embodiment). [0068] An AND circuit 202 calculates and outputs the AND of the normal acceleration signal Saccl, detected acceleration signal, detected water temperature signal, and the inversion of the operation mode signal S301. Likewise, an AND circuit 203 calculates and outputs the AND of the starting acceleration signal Sacc2, detected acceleration signal, detected water temperature signal, and the operation mode signal S301. [0069] If the outputs of the AND circuits 202 and 203 are all at "L" level, that is, if the vehicle is not in the state of acceleration, an ignition- timing- in- acceleration correcting unit 204 informs the ignition controller 161 of the standarignition timing (Fig. 16) determined by the standard ignition timing determining unit 207. The ignition controller 161 executes an igniting operation at the ignition timing notified through the ignition- timing- in- acceleration correcting unit 204. [0070] When the output of the AND circuit 202 is at "H" level, that is, as shown in Fig. 14, when in the "start & idle SW mode" the engine speed Ne is 700 rpm [0071] On the other hand, when the output signal from the AND circuit 203 is at "H" level, that is, as shown in Fig. 14, when in the "stop/start mode" the engine speed is 700 rpm [0072] When the output of either the AND circuit 202 or the AND circuit 203 goes "H", the ignition- timing- in- acceleration correcting unit 204, which is provided with a counter 204a,executes the above retard ignition immediately by a predetermined number of times (three times in this embodiment) and there after a return is made immediately to the normal ignition timing determined by the standard ignition timing determining unit 207. [0073] According to such an ignition knock control, it is possible to set a retard amount in normal acceleration from a medium-speed revolution region and a retard amount in starting acceleration which retard quantities are different from each other. By setting the latter larger than the former it is possible to prevent knocking not only in normal acceleration from the medium-speed rotational region but also in starting acceleration. [0074] In the headlight control section 800 shown in Fig. 11, an Ne determining unit 801 determines whether the engine speed is a preset number of revolutions (less than idling revolutions) or higher in accordance with a detection signal provided from the Ne sensor 153 and outputs an "H" level signal if the answer is affirmative. An AND circuit 802 outputs an AND of the output signal from the Ne determining unit 801 and the inversion of the operation mode signal S301. An AND circuit 803 outputs an AND of the output signal from the Ne determining unit 801 and the operation mode signal S301. [0075] A lighting/dimming switching unit 804 outputs an "H" level signal if the output signal from the AND circuit 802 is at level, while it outputs a pulse signal with a duty ratio of 50% if the output signal from the AND circuit 802 is at "L" level. A lighting/multi-stage dimming switching unit 805 outputs an "H" level signal if the output signal from the AND circuit 803 is at "H" level, while if the output signal from the AND circuit 803 is at "L" level, the lighting/multi-stage dimming switching unit 805 counts the duration of "L" with use of a timer 805a and outputs a pulse signal having a duty ratio which decreases stepwise in accordance with the duration. In this embodiment, the duty ratio is decreased from 95% to 50% stepwise in one second. According to such a stepwise dimming method, the light quantity decreases in an instant and linearly, so that power saving and the maintenance of high commerciality are attained. [0076] According to such a headlight control, as shown in Fig. 13, in the "start & idle SW mode" the headlight is turned ON or dimmed in accordance with the engine speed Ne, while in the "stop/start mode" the headlight is turned ON or dimmed stepwise in accordance with the engine speed Ne. Thus, discharge of the battery can be suppressed during stop of the vehicle while ensuring high visibility from an oncoming vehicle . Asaresult, in subsequent starting it is possible to decrease the amount of charge from the generator to the battery, that is, the electric load on the generator decreases, so that the acceleration performance in starting is improved. [0077] In the bistarter control section 900, a detection signal provided from the water temperature sensor 155 is inputted to 31 a water temperature determining unit 901. If the water temperature is not lower than a first predetermined value (50 °C in this embodiment) , the water temperature determining unit 901 outputs an "H" level signal to close the bistarter relay, while when the water temperature becomes not higher than a second preset value (10'C in this embodiment), the water temperature determining unit 901 outputs an "L" level signal to open the bistarter relay 164. [0078] According to such a bistarter control, fuel becomes rich as the water temperature rises and becomes lean automatically as the water temperature drops. In this embodiment, moreover, since the opening/closing temperature of the bistarter relay 164 is given hysteresis, it is possible to prevent unnecessary opening/closing motions of the bistarter relay 164 which occur in the vicinity of a critical temperature. [0079] In the charging control section 500 shown in Fig. 11, a detection signal provided from the vehicle speed sensor 155 and a detection signal from the throttle sensor 257 are inputted to an accelerating operating detecting unit 502, and as shown in Fig. 14, when the vehicle speed is higher than zero and the throttle valve is opened from fully closed to fully open condition within 0.3 second, the accelerating operation detecting unit 502 judges that an accelerating operation has been done, and produces an acceleration detection pulse. [0080] In response to the acceleration detection pulse signal a charging-in-acceleration limiting unit 504 controls the regulator rectifier 167 and causes the charging voltage of the battery 168 to drop from normal 14.5V to 12.0V. [0081] Further, the charging-in-acceleration limiting unit 504 starts a timer 504a for 6 seconds in response to the acceleration detection pulse, then upon lapse of the time set to the timer 504a or when the engine speed Ne has increased to a preset number of revolutions or higher or when the throttle valve opening decreases, the limitation on the charging is cancelled and the charging voltage is returned from 12.0V to 14.5V. [0082] To an accelerating operation detecting unit 503 are inputted detection signals from the vehicle speed sensor 255, Ne sensor 153 and throttle sensor 257. As shown in Fig. 14, if the throttle valve is open when the vehicle speed is zero and the engine speed Ne is not higher than a preset number of revolutions (2500 rpm in this embodiment), the accelerating operation detecting unit 503 judges that an accelerating operation has been performed, and produces a starting detection pulse. [0083] Upon detection of the starting detection pulse the charging-in-start limiting unit 505 controls the regulator rectifier 167 to let the charging voltage of the battery 168 drop from normal 14.5V to 12.0V. tarts a timer 505a for 7 seconds in response to the starting detection pulse, and upon lapse of the time set to the timer 505a or when the engine speed Ne becomes a preset number of revolutions or higher or when the throttle valve opening decreases, the limitation on the charging is cancelled and the charging voltage is returned from 12.0V to 14.5V. [0085] According to such a charging control, when the vehicle driver opens the throttle valve suddenly to make rapid acceleration or upon starting from a stopped state of the vehicle, the charging voltage is kept low and an electric load on the generator 172 is diminished temporarily, so that a mechanical load on the engine 200 is reduced and the acceleration performance is improved. [0086] At a timing at which the vehicle driver can start the engine experientially with the starter switch, the after-stop non-sitting control section 100 shown in Fig. 12 permits exceptionally the engine starting with the starter switch 258. [0087] An AND circuit 102 calculates the AND of the operation mode signal S301 and the inversion of an output signal from the sitting switch 254 and outputs the AND. If "H" level of the AND circuit 102 is detected for a predetermined time or longer after automatic stop of the engine, that is, if a non-sitting condition of the vehicle driver continues for a predetermined time or longer after automatic stop of the engine in the "stop/start mode", a non-sitting continuance determining unit 101, which is provided with a timer 101a, sets the output signal to "H" level. As a result, the ignition controller 161 is energized, assuming an ignition permitted state. [0088] An OR circuit 103 calculates and outputs the OR of output signals from the starter switch 258 and the throttle switch 257. An AND circuit 104 calculates the AND of output signals from the non-sitting continuance determining unit 101 and the OR circuit 103 and outputs it to the starter relay 162. More specifically, if a non-sitting condition of the vehicle driver continues for a predetermined time or longer ("H" level output of the non-sitting continuance determining unit 101) after automatic stop of the engine in the "stop/start mode" and if the starter switch 258 is turned ON or the throttle valve is opened thereafter, the starter relay 162 is energized to turn ON the starter motor 171. At this time, since the ignition controller 161 is energize by the non-sitting continuance determining unit 101, it is possible to start the engine. [0089] According to such an after-stop non-sitting control, if a non-sitting condition of the vehicle driver is detected continuously for a predetermined time, even after the engine has been stopped in response to a predetermined stop condition, starting of the engine with the starter switch 258 is permitted exceptionally. Therefore, even if the engine is stopped automatically to stop the vehicle and the vehicle driver leaves the vehicle without turning OFF the main power supply and even if the driver when returned to the vehicle operates the starter switch 258, forgetting that the vehicle is under automatic engine stop control, it is possible to start the engine in the same way as in the normal condition. [0090] In the above after-stop non-sitting control, the starting of the engine with the starter switch 258 is permitted exceptionally on condition that a non-sitting condition of the driver has continued for a predetermined time or longer after automatic engine stop in the "stop/start mode", but as indicated with a broken line in Fig. 12, a modification may be made such that the starting of the engine with the starter switch 258 may be permitted by controlling the operation switching section 300 and thereby switching the operation mode from "stop/start mode" to "start & idle SW mode." Or as described "Condition 5" in Fig. 15, by turning OFF the main switch 173, the starting of the engine with the starter switch 258 may be substantially permitted. [0091] Fig. 3 is a sectional view of a swing unit according to a second embodiment of the present invention, in which the same reference numerals as in the previous embodiment represent the same or equivalent portions. [0092] In the previous first embodiment the sprocket 58 connected to the starting motor 49 is connected to the outer rotor 42 of the generator 44 through the one-way clutch 50, but in this second embodiment the sprocket 58 is connected to the crank shaft 12 through a one-way clutch 50 having the same function as above and at a position between the pulley 83 and the main bearing 10 both located on the side opposite to the generator 44 with respect to the crank chamber 9. [0093] The one-way clutch 50 is made up of one sleeve 57b fixed onto the crank shaft 12, the other sleeve 55b which supports the sprocket 58 rotatably with respect to the crank shaft 12, and a clutch portion 56b which couples the sleeves 55b and 57b so as to inhibit the crank shaft 12 from idling in the reverse direction relatively with respect to the sprocket 58 and permit idling of the crank shaft in the reverse direction. [0094] According to this embodiment, since the sprocket 58 for transmitting the driving force of the starting motor 49 to the crank shaft 12 is disposed on the pulley 83 side of the automatic transmission with respect to the crank chamber 9 and the crank length on the automatic transmission side with respect to the crank chamber 9 is set larger than its length on the generator side, the center of the engine can be positioned at the tire center, i.e., the center of the vehicle. Consequently, the swing unit 17 is difficult to undergo twist or moment, the weight distribution is improved and so is the traveling stability. [0095] According to this embodiment, moreover, since the sprocket 58 connected to the starting motor 49 is connected to the crank shaft 12 at a position spaced away from the tire 21 axially of the crank shaft, the sprocket 58 can be made large in diameter and a large reduction ratio is obtained, so that t is possible to reduce the size and weight of the starting motor 49. [0096] Fig. 4 is a sectional view of a swing unit 17 according to a third embodiment of the present invention, in which the same reference numerals as in the previous embodiments represent the same or equivalent portions. [0097] In this third embodiment, a crank shaft-side sleeve 57c of the one-way clutch 50 is formed integrally on the rear side of the fixed pulley piece 83a, i.e., the side not abutted against the V belt 82, while another sleeve 55c is fixed to a flange portion 83d which is extended axially outwards of the fixed pulley piece 83a, whereby the sprocket 58 is connected to an end portion of the crank shaft 12 through the one-way clutch 50 and the fixed pulley piece 83a. [0098] According to this embodiment, since the sprocket 58 and the chain 40 entrained thereon are mounted at the outermost end of the crank shaft 12, their mounting and removal can be done easily and it becomes easy to effect maintenance. Besides, the mounting of an existing swing unit after remodeling also becomes very easy. [0099] Further, also in this embodiment, like the second embodiment, the sprocket 58 is connected to the crank shaft 12 at a position spaced away from the tire 21 axially of the crank shaft, so that it becomes possible to increase the diameter of he sprocket 58 and a large reduction ratio is obtained, thus permitting the reduction in size and weight of the starting motor 49. [0100] Fig. 6 is a sectional view of a principal portion of a swing unit 17 according to a fourth embodiment of the present invention and Fig. 7 is a sectional view of the swing unit 17 taken along a plane perpendicular to the crankshaft 12, in which the same reference numerals as in the previous embodiments represent the same or equivalent portions. [0101] In the previous first to third embodiments the sprocket 58 mounted on the crank shaft 12 and the starting motor 58 are connected together through the chain 40. On the other hand, in this fourth embodiment, the sprocket 58 and the starting motor 49 are normally connected together through a gear train, and the crank shaft 12 and the sprocket 58 are connected together through the one-way clutch as in the previous embodiment, whereby the transmission of power from the crank shaft 12 side to the starting motor 49 side is cut off without using a sliding pinion. Thus, since one-way connection from the starting motor to the crank shaft can be done without using a sliding pinion, it becomes possible to reduce the engine starting noise. [0102] In Figs. 6 and 7, gear teeth 221 are formed on the rotary shaft of the starting motor 49 and a large-diameter gear 222, which is connected to a drive shaft 234, is in mesh with the gear teeth 221. Further, on the drive shaft 234 is formed a 39 small-diameter gear 223 coaxially with and adjacent the large-diameter gear 222 and the sprocket 58 on the crank shaft 12 is engaged with the small-diameter gear 223. [0103] For preventing the increase of noise caused by sliding wear or by abrasive wobbling in the engine starting system involving a high engine starting frequency, the drive shaft 234 is supported rotatably by a pair of oil - retaining bush type bearings 234a and 234b at both side portions with the large-and small-diameter gears 222, 223 therebetween. In this embodiment, for suppressing noise generated from the above gear train, the gear teeth meshing with each other are subjected to shaving or polishing. [0104] In this embodiment a sliding pinion is not adopted for connection between the sprocket 58 mounted on the cranks haft 12 and the starting motor 49, but both are connected together constantly using a fixed gear train, it becomes necessary to separately provide a configuration for one-way connection which permits the transfer of power from the starting motor 49 side to the crank shaft 12 side but inhibits the power transfer from the crank shaft 12 side to the starting motor 49 side. In this embodiment, therefore, the sprocket 58 is connected to the crank shaft 12 through the one-way clutch 50 as in the previous embodiment. [0105] Accordingly, when the starting motor 49 is driven at the time of starting the engine and the sprocket 58 is rotated the forward direction of the crank shaft 12, the crank shaft is also rotated in the forward direction, following the rotation of the sprocket 58. After start-up of the engine, the crank shaft 12 idles with respect to the sprocket 58 even if the starting motor 49 turns OFF and therefore the driving force of the crank shaft is not transmitted to the starting motor 49. [0106] According to this embodiment, as set forth above, since the starting motor 49 and the crank shaft 12 can be connected together without using a sliding pinion, there does not occur an operation noise of sliding pinion and the engine starting noise can be so much kept lower. [0107] [Effect of the Invention] The following effects are attained by the present invention. [0108] (1) According to the invention defined in claim 1, since the starting motor can be driven for the reference time or longer even when the starting operation for driving the starting motor is performed for only a short time, it is possible to prevent the occurrence of kick-back caused by a short operation time of the starting motor and hence possible to reduce the engine starting noise. [0109] (2) According to the invention defined in claim 2, when the vehicle driver wants to drive the starting motor long of the driver's own will, it is possible to do so. [0110] (3) According to the invention defined in claim 3, in a vehicle wherein a starting motor is started with a starter switch, it is possible to prevent the occurrence of kick-back at the time of starting the engine and thereby reduce the engine starting noise. [0111] (4) According to the invention defined in claim 4, in a vehicle equipped with an automatic engine stop/start system, it is possible to prevent the occurrence of kick-back at the time of starting the engine and thereby reduce the engine starting noise . [0112] (5) According to the invention defined in claims 5 and 6, the piston which has stopped before the top dead center in explosion can be moved up to a position exceeding the top dead center in explosion which follows immediately and also exceeding the next top dead center in explosion, thus making it possible to positively prevent the occurrence of kick-back at the time of starting the engine. 42 We claim: 1. A 4 cycle engine starting system wherein a starting motor is driven in response to an engine starting operation, the engine starting system comprising; a start signal generating means which generates a start signal corresponding to the period of the starting operation; characterized in that a start signal extending means which extends a start signal shorter than a predetermined reference time to the predetermined reference time or longer and outputs the thus-extended signal; the start signal extending means extends the start signal in such a manner that a piston when stopped just before an explosive top dead center is moved up to a position which exceeds an explosive top dead center just thereafter and the next explosive top dead center; and a drive means which drives the starting motor in accordance with an output signal provided from the start signal extending means. 2. An engine starting system as claimed in claim 1, wherein when a start signal longer than the predetermined reference time is inputted, the start signal extending means outputs the inputted start signal as it is without extending it. 3. An engine starting system as claimed in claim 1 or claim 2, comprising a starter switch for driving the starting motor, and wherein the start signal generating means generates the start signal for only an ON period of the starter switch. -44- 4. An engine starting system as claimed in claim 3, comprising an automatic stop/start system which stops the engine in response to predetermined stop conditions during travel of a vehicle and which, after the stop, restarts the engine in response to a throttle valve opening operation, and wherein the start signal generating means generates the start signal only for the ON period of the starter switch or for the period of the throttle valve opening operation. 5. An engine starting system as claimed in any of claims 1 to 4, wherein the start signal extending means extends the start signal in such a manner that a piston is moved up to a position which exceeds an explosive top dead center just after explosion in a cylinder with the piston fitted therein. 6. An engine starting system substantially as herein described with reference to the accompanying drawings. Dated this 19/06/2001 [VARUN SHARMA] OF REMFRY & SAGAR ATTORNEY FOR THE APPLICANT]

Full Text

FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
&
THE PATENTS RULES, 2003 COMPLETE SPECIFICATION
[See Section 10; rule 13]
"A 4 CYCLE ENGINE STARTING SYSTEM"
HONDA GIKEN KOGYO KABUSHIKI KAISHA, a corporation of Japan, 1-1, Minamiaoyama 2-chome, Minato-ku, Tokyo, Japan
The following specification particularly describes the nature o the invention and the manner in which it is to be performed:-

The present invention relates to a 4 cycle engine starting system.
[Detailed Description of the Invention] [0001] [Technical Field of the Invention]
The present invention relates to an engine starting system for starting an engine with use of a starting motor and more particularly to an engine starting system suitable for a vehicle adopting an automatic stop/start system which stops an engine automatically in response to predetermined stop conditions during travel of the vehicle and which, after the stop, restarts the engine in response to a predetermined starting operation. [0002] [Prior Art]
For suppressing noise generated at the time of starting

an engine there have been proposed various techniques, including the technique disclosed in Japanese Unexamined Patent Publication No. Hei 11-30139 for example.
[0003] [Problem to be Solved by the Invention]
At the time of starting an engine, if the time of a starting operation performed by the driver of a vehicle is short and hence a starting motor is driven for only an extremely short time, the starting motor will stop before a piston exceeds a top dead center just after explosion and an explosion load will act in a reversing direction, with consequent occurrence of a crank shaft reversing phenomenon, i.e., what is called kick-back, and occurrence of knocking noise or gear noise.
[0004]
It is an object of the present invention to solve the above-mentioned problem of the prior art and provide an engine starting system capable of keeping low the engine starting noise.
[0005] [Means for Solving the Problem]
According to the present invention, for achieving the above-mentioned object, there is provided an engine starting system wherein a starting motor is driven in response to an engine starting operation, the engine starting system including a start signal generating means which generates a start signal corresponding to the period of the starting operation, a start signal extending means which extends a start signal shorter than a predetermined reference time to the predetermined reference
3

time or longer and outputs the thus - extended signal, and a drive means which drives the starting motor in accordance with an output signal provided from the start signal extending means. [0 006]
According to the above feature, even when the starting operation for driving the starting motor is performed for only a short time, it is possible to let the starting motor operate for the reference time or longer. Therefore, it is possible to prevent the occurrence of kick-back at the time of starting an engine due to a short driving time of the starting motor and hence possible to reduce the engine starting noise.
4

automatic engine stop/start system;
Fig. 4 is a sectional view of a swing unit according to a third embodiment of the present invention equipped with an automatic engine stop/start system;
Fig. 5 is a side view of a motorcycle with an automatic engine stop/start system mounted thereon;
Fig. 6 is a sectional view of a swing unit according to a fourth embodiment of the present invention equipped with an automatic engine stop/start system;
Fig. 7 is a sectional view of the swing unit of the fourth embodiment taken along a plane perpendicular to the crank shaft;
Fig. 8 is a block diagram of an automatic engine stop/start system embodying the present invention;
Fig. 9 is a block diagram (No.l) showing functions of a main control system;
Fig. 10 is a block diagram (No.2) showing functions of the main control system;
Fig. 11 is a block diagram (No.3) showing functions of the main control system;
Fig. 12 is a block diagram (No.4) showing functions of the main control system;
Fig. 13 is a table (No.l) showing principal operations of the main control system;
Fig. 14 is a table (No.2) showing principal operations of the main control system;
Fig. 15 is a diagram showing conditions for operation mode switching;
Fig. 16 is a diagram showing a relation of engine speed

[0007] [Mode for Carrying Out the Invention]
The present invention will now be described in detail with reference to the drawings. Fig. 5 is an entire side view of a motorcycle with an engine stop/start control system according to the present invention mounted thereon. A front portion 2 of a vehicle body and a rear portion 3 of the vehicle body are connected together through a low floor portion 4 and a framework of the vehicle body is constituted by a body frame which includes a down-tube 6 and a main pipe 7. A fuel tank and a receptacle box (neither shown) are supported by a main pipe 7 and a seat 8 is disposed thereon. The seat 8 can also serve as a lid of a luggage box which underlies the seat. The luggage box is constituted so that it can be opened and closed by a hinge mechanism provided in a front portion FR of the box.
[0008]
In the front portion 2 of the vehicle body, a steering

head 5 is secured to the down-tube 6 and a front fork 12A is pivotally supported by the steering head 5. A handle 11A is attached to an upper end of the front fork 12A, while a front wheel 13A is connected to a lower end of the front fork through an axle. The handle 11A is covered from above with a handle cover 33 which also serves as an instrument panel. [0009]
At an intermediate position of the main pipe 7 is supported a link member (hanger) 37 pivotably and a swing unit 17 is connected to the main pipe 7 pivotably through the hanger 37. A single-cylinder 4-cycle engine 200 is mounted to a front portion of the swing unit 17 . A belt type continuously variable transmission 35 is constituted so as to extend backward from the engine 200. At a rear portion of the transmission 35 is mounted a reduction mechanism 38 through a centrifugal clutch and a rear wheel 21 is connected to the reduction mechanism 38 through an axle. A rear cushion 22 is interposed between an upper end of the reduction mechanism 38 and an upper bent portion of the main pipe 7. [0010]
An intake pipe 23 extending from a cylinder head 32 of the engine 200 is connected to the front portion of the swing unit 17. Further, a carburetor 24 and an air cleaner 25 connected to the carburetor are disposed in the intake pipe 23. A pivot shaft 18 is mounted at a lower portion of a swing unit case 31 and a main stand 26 is pivotally connected to the pivot shaft 18. For parking, the main stand 26 is brought upright (indicated with a chain line).

9

[0011]
Fig. 1 is a sectional view of the swing unit 17 according to a first embodiment of the present invention, which corresponds to a sectional structure taken along line A-A in Fig. 5, and Fig. 2 is a sectional view of the swing unit 17 taken along a plane perpendicular to a crank shaft. The swing unit 17 is provided with an engine 200 disposed in a front position of a vehicle, a power generating section G connected to one end of a crank shaft 12 , and a driving section ATI and a driven section AT2 of an automatic transmission connected to the opposite end of the crank shaft 12.
[0012]
In a swing unit case 31 is mounted the crank shaft 12 which is supported rotatably by main bearings 10 and 11. A connecting rod 14 is connected to the crank shaft 12 through a crank pin 13. A generator 44 is mounted on one end of the crank shaft 12 overhanging from a crank chamber 9.
[0013]
One (crank shaft-side) sleeve 57a of a one-way clutch 50 is fixed with screw 43 to an outer rotor 42 of the generator 44, while the other (sprocket-side) sleeve 55a is rotatably supported integrally with a sprocket 58 by the crank shaft 12 at a position between the generator 44 and the main bearing 11. On the sprocket 58 is entrained a chain 40 for obtaining a starting torque from a starting motor 49 shown in Fig. 2.
[0014]
A clutch portion 56a of the one-way clutch 50 prevents the outer rotor 42 of the generator 44, i.e., crank shaft 12,

from idling in a reverse direction relatively with respect to the sprocket 58 and permits the crank shaft from idling in a forward direction. Therefore, when the starting motor 49 is operated at the time of starting the engine and the sprocket 58 is rotated in the forward direction of the crank shaft 12, the crank shaft also rotates in the forward direction following the rotation of the sprocket.
[0015]
After start-up of the engine, the crank shaft idles with respect to the sprocket 58 even if the starting motor 49 turns OFF and therefore the driving force of the crank shaft 12 is not transmitted to the starting motor 49.
[0016]
A sprocket 59 is fixed onto the crank shaft 12 at a position between the sprocket 58 and the main bearing 11. A chain 60 is entrained on the sprocket 59 to obtain power for driving a cam shaft 69 from the crank shaft 12. The sprocket 59 is formed integrally with a gear 61 which is for transmitting power to a lubricating oil circulating pump (not shown).
[0017]
A piston 63 disposed within a cylinder 62 is connected to a small end side of a connecting rod 14. A spark plug 65 is threadedly engaged with a cylinder head 32 so that an electrode portion thereof faces a combustion chamber formed between the head of the piston 63 and the cylinder head 32 . The cylinder 62 is surrounded by a water jacket 66.
[0018]
The cam shaft 69 is supported rotatably within the

11

cylinder head 32 and above the cylinder 62, with a cam sprocket 72 being fixed onto the cam shaft 69. The chain 60 is entrained on the cam sprocket 72 to transmit rotation of the sprocket 59, i.e., rotation of the crank shaft 12, to the cam shaft 69.
[0019]
A rocker arms 73 is disposed on the cam shaft 69. As the cam shaft 69 rotates, the rocker arm 73 swings in accordance with the cam shape of the cam shaft. The cam shape of the cam shaft 69 is determined so that intake and exhaust valves 95 and 96 are opened and closed according to strokes of the four-cycle engine.
[0020]
A pulley 83, on which a V belt 82 is to be entrained, is mounted on an end portion of the crank shaft 12 on the side opposite to the side where the generator 44 is disposed. The pulley 83 comprises a fixed pulley piece 83a whose movements in both rotational and axial directions are fixed with respect to the crank shaft 12 and a movable pulley 83b which is slidable in the axial direction with respect to the crank shaft. A holder plate 84 is attached to a rear side, i.e., the side not abutted against the V belt, of the movable pulley piece 83b. The holder plate 84 is adapted to rotate integrally with the crank shaft 12 while its movements in both rotational and axial directions are inhibited. The space surrounded by both holder plate 84 and movable pulley piece 83b forms a pocket which receives therein a roller 85 serving as a governor weight.
[0021]
A fan 83c is integrally formed on a rear side, i.e., the

12

side not abutted against the Vbelt 82, of the fixed pulley piece 83a and an air cleaner governor 70 provided with an air cleaner 71 for cleaning and introducing cooling air into an automatic transmission chamber is applied to an opening of the swing unit case 31 opposed to the fan 83c. The fan 83c is formed so as to suck the outside air into the automatic transmission chamber through the air cleaner 71 upon forward rotation of the crank shaft 12.
[0022]
In the driven section A2 of the automatic transmission, a fixed pulley piece 132a of a pulley 132 is mounted on a main shaft 125 of a clutch. A cup-like clutch disc 134 is fixed onto an end portion of the main shaft 125 with use of a nut 133. A movable pulley piece 132b of the pulley 132 is mounted on a sleeve 135 of the fixed pulley piece 132a so as to be slidable in the longitudinal direction of the main shaft 125. The movable pulley piece 132b is engaged withadisc 136 soas tobe integrally rotatable around the main shaft 125. Between the disc 136 and the movable pulley piece 132b is mounted a compression spring 137 having a repulsive force acting in a direction to expand the distance between the two. The main shaft 125, an idle shaft 142 and an output shaft 145 are engaged with one another and a rim 21a of a rear wheel 21 is fixed to the output shaft 145.
[0023]
In this embodiment, as described above, since the starting motor 49 and the crank shaft 12 are connected together through a chain 40 as an endless connecting means and the crank shaft 12 is driven by the chain at the time of start-up of the engine,
13

^ the starting noise caused by the starting motor can be kept lower than in the prior art. [0024]
In the case where the generator 44 and the pulley 83 of the automatic transmission are disposed respectively on both ends of the crank shaft 12 with the crank chamber 9 therebetween as in this embodiment, the pulley 83 occupies a larger axial area on the crank shaft than the generator 44. Thus, also as to the crank shaft lengths on both sides of the crank chamber 9, the pulley 83 side tends to be longer than the generator 44 side. In this embodiment, however, since the sprocket 58 and the one-way clutch 50 thereof are provided on the generator 44 side, the crank shaft lengths on both sides of the crank chamber 9 can be made equal to each other and thus can be stabilized in their rotational balance.
[0025]
According to this embodiment, moreover, the chain 40 for connecting the crank shaft 12 and the starting motor 49 and the chain 60 for connecting the crank shaft 12 and the cam shaft 69 can be gathered on one side of the engine, so that the maintainability is improved.
[0026]
A description will now be given of an automatic engine stop/start system to which the present invention is applied. This system has an operation mode (hereinafter referred to as the "start & idle switch (SW) mode" which permits idling and an operation mode ("stop/start mode" hereinafter) which restricts (or inhibits) idling.
14

[0027]
In the "start & idle switch (SW) mode", idling is permitted temporarily upon initial start-up of the engine after turning ON of a main power supply for the purpose of warming-up at the time of starting the engine. Even when the engine condition is not after initial start-up thereof, idling is permitted by the driver's will (turning ON the idle SW). [0028]
On the other hand, in the "stop/start mode" in which idling is restricted, the engine stops automatically when the vehicle is stopped, and if an accelerator pedal is operated with engine OFF, the engine is restarted automatically, making it possible to start the vehicle. [0029]
Fig. 8 is a block diagram showing an entire configuration of the automatic engine stop/start system in the engine 200, in which the same reference numerals as above represent the same or equivalent portions.
[0030]
A generator (AC generator 172) is mounted on the crank shaft 12 coaxially and electric power generated by the generator 172 is charged into a battery 168 through a regulator rectifier 167. The regulator rectifier 167 controls an output voltage of the generator 172 to 12V to 14.5V. The battery 168 supplies a driving current to a starter motor 171 when a starter relay 162 is energized and further supplies a load current to various general electric appliances 174 and a main control system 160 through a main switch 173.

[0031]
To the main control system 160 are connected an Ne sensor 153 for detecting the number of revolutions of the engine, or engine speed, Ne, an idle switch 253 for permitting or restricting idling of the engine 200 manually, a sitting switch 254 which, upon sitting of the driver on a driver seat, closes a contact and outputs "H" level, a vehicle speed sensor 255 for detecting the vehicle speed, a stand-by indicator 256 which flickers in the "stop/start mode", a throttle sensor 257 (including a throttle switch 257a) for detecting a throttle opening 9 , a starter switch 258 for driving the starter motor 171 to start the engine 200, a stop switch 259 which outputs "H" level in response to a braking operation, a battery indicator 276 which goes ON upon drop in voltage of the battery 168 to below a predetermined value (for example, 10V) and warns the driver of insufficient charging, and a water temperature sensor 251 for detecting the temperature of engine cooling water.
[0032]
Further connected to the main control system 160 are an ignition controller (including an ignition coil) 161 which causes the spark plug 65 to ignite in synchronism with rotation of the crank shaft 12, a control terminal of the starter relay
162 which supplies electric power to the starter motor 171, a control terminal of a headlight driver 163 which supplies electric power to a headlight 169, and a control terminal of a bistarter relay 164 which supplies electric power to a bistarter 165 mounted to a carburetor 166 . The headlight driver
163 is constituted by a switching element such as a FET and adopts

16

what is called chopping control in which the switching element is turned on and off at predetermined cycle and duty ratio to substantially control the voltage to be applied to the headlight 169.
[0033]
Figs. 9 to 12 are block diagrams (No. 1, No . 2 , No . 3 , No. 4) , in which the same reference numerals as in Fig.8 represent the same or equivalent portions.
[0034]
Figs. 13 and 14 tabulate control contents of components of the main control system which components are a starter relay control section 400, a bistarter control section 900, a stand-by indicator control section 600, a headlight control section 800, an after-stop non-sitting control section 100, an ignition control section 700, an ignition knock control section 200, and a charging control section 500.
[0035]
In Fig. 9, when the state of the idle switch 253 and that of the vehicle satisfy predetermined conditions, an operation switching section 300 switches the operation mode of the main control system 160 to either "start & idle SW mode" or "stop/start mode."
[0036]
A state signal from the idle switch 253 is inputted to an operation mode signal output unit 301 in the operation switching section 300. The state signal from the idle switch 253 indicates "L" level when it is OFF (idling restriction) and "H" level when it is ON (idling permission). In response to

17

output signals provided from the idle switch 253, vehicle speed sensor 255 and water temperature sensor 155 the operation mode signal output unit 301 outputs an operation mode signal S301 which specifies the operation mode of the main control system 160 to either "start & idle SW mode" or "stop/start mode."
[0037]
Fig. 15 schematically illustrates operation mode switching conditions adopted in the operation mode signal output unit 301. When the main switch 173 is turned ON to reset the main control system 160 (condition 1 is established), the operation mode signal S301 is set to "L" level to start the "start & idle SW mode."
[0038]
In the "start & idle SW mode", if a vehicle speed not lower than a predetermined speed (for example, 10 km/hr), the water temperature is not lower than a predetermined temperature (for example, a temperature high enough to predict completed warming-up) and the idle switch 253 is OFF (condition 2 is established), the operation mode signal S301 is switched from "L" to "H" level to start the "stop/start mode."
[0039]
In the "stop/start mode", if the idle switch SW is turned from OFF to ON (condition 3 is established) , the operation mode signal S301 is switched from "H" to "L" level to return the operation mode from "stop/start mode" to "start & idle SW mode. " In both "stop/start mode" and "start & idle SW mode", an OFF state is established once the main SW 173 is turned OFF (condition 4 is established).
18

[0040]
Turning back to Fig. 9, the starter relay control section 400 starts up the starter relay 162 in accordance with each of the above operation modes and under predetermined conditions. A detection signal provided from the Ne sensor 153 is inputted to both a below-cranking- revolutions determining unit 401 and a below-idling-revolutions determining unit 407. When the engine speed corresponds to predetermined cranking revolutions (for example, 600 rpm) or lower, the below-cranking-revolutions determining unit 401 outputs an "H" level signal. Likewise, when the engine speed corresponds to predetermined idling revolutions (for example, 1200 rpm), the
below-idling-revolutions determining unit 407 outputs an "H" level signal.
[0041]
An AND circuit 402 outputs an AND of the output signal provided from the below- cranking- revolutions determining unit 401, a state signal from the stop switch 259 and a state signal from the starter switch 258. The AND circuit 404 outputs an AND of the output signal provided from the below- idling-revolutions determining unit 407, a detection signal from the throttle switch 257a and a state signal from the sitting switch 254.
[0042]
An AND circuit 403 outputs an AND of the output signal provided from the AND circuit 402 and the inversion of the operation mode signal S301. An AND circuit 405 outputs an AND of the output signal provided from the AND circuit 404 and the

19

operation mode signal S301. An OR circuit 406 ORs the output signals of the AND circuits 403 and 405 with each other and outputs the OR as a start signal Sin. If the pulse width of the start signal Sin is shorter than a predetermined reference time, a start signal extending unit 407 extends the pulse width to a width not shorter than the reference time and outputs the thus pulse width extended signal to the starter relay 162. [0043]
The start signal extending unit 407 includes a multivibrator 407a which detects the start signal Sin and outputs a one-shot pulse signal and an OR circuit 407b which ORs the start signal Sin with the output signal of the multivibrator 407a and outputs the OR as a start signal Sout after extension. The multivibrator 407a can extend the pulse width of its output pulse as desired according to the resistance value of a variable resistor. [0044]
Fig. 18 is a timing chart showing the operation of the start signal extending unit 407. A variable resistance value of the multivibrator 407a is set so as to give an output pulse width of 0 . 6 second irrespective of the pulse width ton of the start signal Sin. Therefore, even when the starter switch 258 is turned ON for only a shorter period than 0.6 seconds, the output pulse width of the multivibrator 4 07a becomes 0 . 6 second.
[0045]
Further, since the OR circuit 407b outputs an OR of the output pulse from the multivibrator 407a and the start signal Sin, the output signal Sout from the start signal extending unit

20

407 comes to have a pulse width of 0 . 6 seconds if the pulse width ton of the start signal Sout is shorter than 0.6 seconds, while if the pulse width ton of the start signal Sin is longer than 0.6 seconds, the output signal Sout comes to have the same pulse width.
[0046]
Although in the above embodiment the start signal is extended up to 0.6 second, the present invention is not limited thereto, but it is necessary to set an optimum pulse width in accordance with the rotational speed of the starting motor 49 and the reduction ratio.
[0047]
More specifically, as shown in Fig. 19, when the engine is stopped, it is very likely that the piston will stop in the compression stroke just before reaching the top dead center (TDC) in explosion. Then, in the next engine starting operation, if the starting motor 49 is driven from this state, the engine does not ignite just before TDC in explosion which immediately follows, but ignites only just before the next TDC in explosion. Thus, the starting motor 49 is required to rotate the engine so that the piston reaches at least the next TDC in explosion which follows the just-after TDC.
[0048]
However, if the starting motor 49 stops at the time when the piston has reached near the next TDC in explosion which follows the just-after TDC, an explosion load will be exerted in the reversing direction and there occurs what is called kick-back, i.e., reverse rotation of the crank shaft 12.

21

Therefore, it is desirable that the extension time by the start signal extending unit 407 be set to the time required for the piston which has stopped just before TDC in explosion to be driven up to a position exceeding TDC in compression which immediately follows the TDC in explosion and the next TDC in compression.
[0049]
In this embodiment, as described above, the start signal extending unit 407 is provided, whereby the starter 171 is driven for at least 0 . 6 second even when the starter switch 258 is turned ON for only a shorter period than 0.6 second. Consequently, the occurrence of kick-back at the time of start-up of the engine is prevented and it becomes possible to reduce the engine starting noise.
[0050]
According to this embodiment, moreover, even by opening a throttle grip for only a short time it is possible to let the starting motor operate for the minimum time necessary to start the engine. Therefore, particularly in a vehicle which adopts an automatic centrifugal clutch, the driver can start the engine by an easy throttle operation without paying attention to a rise of the engine speed.
[0051]
According to the above starter relay control, the AND circuit 403 is enabled in the "start & idle switch mode." Therefore, if the starter switch 258 is turned ON by the driver (if the output of the AND circuit 402 goes "H") when the engine speed is below cranking revolutions and with the stop switch

259 ON (during braking operation), the starter relay turns conductive and the starter motor 171 is turned ON.
[0052]
In the "stop/start mode" the AND circuit 405 is enabled. Therefore, if the throttle valve is opened (if the output of the AND circuit 404 goes "H") when the engine speed is below idling speed and with the sitting switch 254 ON (the driver is sitting on the seat), the starter relay 162 turns conductive and the starter motor 171 is turned ON.
[0053]
In the stand-by indicator control section 600 shown in Fig. 10, a detection signal from the vehicle speed sensor 255 is inputted to a vehicle- speed- zero determining unit 601, which in turn outputs an "H" level signal if the vehicle speed is substantially zero. A detection signal from the Ne sensor 153 is inputted to an Ne determining unit 602, which in turn outputs an "H" level signal if the engine speed is below a predetermined value. An AND circuit 603 outputs an AND of the output signals provided from the determining units 601 and 602.
[0054]
An AND circuit 604 ANDs the output signal of the AND circuit 603 with an inverted signal from the sitting switch 254 and outputs the AND. Likewise, an AND circuit 605 outputs an AND of the output signal of the AND circuit 603 and the output of the sitting switch 254. A lighting/blinking control unit 606 produces a lighting signal if the output signal from the AND circuit 604 is "H" level and produces a blinking signal if the output signal from the AND circuit 604 is "L" level. An AND

23

circuit 607 outputs an AND of the output signal from the lighting/blinking control unit 606 and the operation mode signal S301. The stand-by indicator 256 lights in response to the lighting signal and blinks in response to the blinking signal. [0055]
According to such a stand-by indicator control, as shown in Fig. 13, the stand-by indicator 256 lights if the driver does not sit on the seat and blinks if the driver sits on the seat during stop of the vehicle in the "stop/start mode . " Therefore, if the stand-by indicator blinks, the driver can become aware that the vehicle can start running if only the accelerator grip is opened even if the engine is OFF.
[0056]
An ignition control section 700 in Fig. 10 permits or inhibits the igniting operation by the ignition controller 161 under predetermined conditions for each operation mode.
[0057]
In accordance with a detection signal provided from the vehicle speed sensor 255 a travel determining unit 701 determines whether the vehicle is traveling or not and outputs an "H" level signal if the vehicle is traveling. An OR circuit
706 outputs an OR of the output signal from the travel
determining unit 701 and the output signal from the throttle
switch 257a. An AND circuit outputs an AND between the output
signal from the sitting switch 254 and the output signal from
the OR circuit 706. Therefore, the output from the AND circuit
707 goes "H" when the throttle valve is open or when the vehicle
speed is higher than zero and the driver sits on the seat.

24

[0058]
An AND circuit 702 outputs an AND of the output signal from the sitting switch 254 and inverted signals from the travel determining unit 701 and the throttle switch 257a. A timer 703 delays an input signal by a predetermined time (3 seconds in this embodiment) and outputs the delayed signal. A NAND circuit 705 provides an inverted output of an AND between the output signal from the AND circuit 702 and the output signal from the timer 703. Thus, the output of the NAND circuit 705 goes "L" when the throttle valve is closed and when the vehicle speed is zero and the driver sits on the seat. [0059]
While the ignition controller 161 is in its igniting operation, a movable contact of a switching circuit 708 is switched to the NAND circuit 705 side, while it is switched to the AND circuit 707 side when the ignition controller 161 is OFF. An OR circuit 709 ORs the inversion of the operation mode signal S301 with the inversion of the output from the switching circuit 708 and outputs the OR to the ignition controller 161.
[0060]
According to the ignition control section 700 constructed as above, as shown in Fig. 14, in the "start & idle SW mode" the output of the OR circuit 709 is always "H" level and therefore the ignition control is permitted at all times.
[0061]
In contrast therewith, in the "stop/start mode" , when the vehicle stops and the engine is turned OFF automatically, the ignition control is permitted if the driver sits on the seat

25

and the throttle valve is open or if the vehicle speed is higher than zero. On the other hand, when the vehicle comes to stop from its running state and if it is detected that the driver has sat on the seat, the ignition control is inhibited and the engine is turned OFF automatically. But if the driver's sitting on the seat is not detected, the ignition control continues to be permitted, so that the engine is not turned OFF automatically.
[0062]
Therefore, if it is impossible to detect the driver's sitting on the seat due to some trouble of the sitting switch 254, the engine is not turned OFF automatically even when the vehicle comes to stop from its running condition, thus eliminating the need of starting the engine at the time of starting the vehicle. Thus, even if there should occur any trouble of the sitting switch 254 in the system which permits automatic engine starting on condition that the driver sits on the seat, there is no fear that the travel of the vehicle may be impeded.
[0063]
Further, according to this embodiment, even if the driver's sitting on the seat is detected when the vehicle comes to a stop from its running condition, the ignition control is not immediately inhibited, but is inhibited after the lapse of a predetermined time (3 seconds in this embodiment). Consequently, when the vehicle stops at an intersection or at the time of U-turn in a condition such that the driver sits on the seat and the vehicle speed is nearly zero, with the throttle
26

valve being substantially closed fully, it becomes possible let the engine continue to start.
[0064]
The ignition knock control section 200, for each of the operation modes described above, retards the ignition timing in acceleration as compared with that in normal driving to prevent the occurrence of knocking. Particularly in this embodiment, the retard amount in starting acceleration for acceleration from an engine OFF condition is set larger than that in normal,acceleration for acceleration from an engine rotating state, whereby the occurrence of knocking in starting acceleration, which is peculiar to a vehicle equipped with an automatic engine stop/start system, is prevented completely.
[0065] In a standard ignition timing determining unit 207 there is registered a standard ignition timing as an advance angle (deg) from TDC (top dead center in explosion) and as a function of engine speed Ne and throttle opening 9 . Fig. 16 illustrates the engine speed Ne and throttle opening 9 vs. standard ignition timing in this embodiment. As shown in the same figure, the ignition timing set at 15° (deg; advance angle) until the engine speed reaches 2500 rpm, and as the engine speed Ne exceeds 2500 rpm, the amount of advance amount is increased little by little.
[0066]
An Ne determining unit 201 sets a normal acceleration signal Saccl to "H" level if the engine speed Ne is 700 rpm --27

to "H" level if the engine speed is 700 rpm [0067]
When a variation rate A 6 of the throttle opening 9 detected by the throttle sensor 257 exceeds a predetermined value, an acceleration determining unit 205 judges that an accelerating operation has been done and outputs an acceleration detection signal of "H" level. A water temperature determining unit 206 determines the temperature of cooling water on the basis of a detection signal provided from the water temperature sensor 155 and outputs an "H" level signal when the water temperature exceeds a predetermined temperature (50°C in this embodiment).
[0068]
An AND circuit 202 calculates and outputs the AND of the normal acceleration signal Saccl, detected acceleration signal, detected water temperature signal, and the inversion of the operation mode signal S301. Likewise, an AND circuit 203 calculates and outputs the AND of the starting acceleration signal Sacc2, detected acceleration signal, detected water temperature signal, and the operation mode signal S301.
[0069]
If the outputs of the AND circuits 202 and 203 are all at "L" level, that is, if the vehicle is not in the state of acceleration, an ignition- timing- in- acceleration correcting unit 204 informs the ignition controller 161 of the standarignition timing (Fig. 16) determined by the standard ignition timing determining unit 207. The ignition controller 161 executes an igniting operation at the ignition timing notified through the ignition- timing- in- acceleration correcting unit 204.
[0070]
When the output of the AND circuit 202 is at "H" level, that is, as shown in Fig. 14, when in the "start & idle SW mode" the engine speed Ne is 700 rpm [0071]
On the other hand, when the output signal from the AND circuit 203 is at "H" level, that is, as shown in Fig. 14, when in the "stop/start mode" the engine speed is 700 rpm [0072]
When the output of either the AND circuit 202 or the AND circuit 203 goes "H", the ignition- timing- in- acceleration correcting unit 204, which is provided with a counter 204a,executes the above retard ignition immediately by a predetermined number of times (three times in this embodiment) and there after a return is made immediately to the normal ignition timing determined by the standard ignition timing determining unit 207.
[0073]
According to such an ignition knock control, it is possible to set a retard amount in normal acceleration from a medium-speed revolution region and a retard amount in starting acceleration which retard quantities are different from each other. By setting the latter larger than the former it is possible to prevent knocking not only in normal acceleration from the medium-speed rotational region but also in starting acceleration.
[0074]
In the headlight control section 800 shown in Fig. 11, an Ne determining unit 801 determines whether the engine speed is a preset number of revolutions (less than idling revolutions) or higher in accordance with a detection signal provided from the Ne sensor 153 and outputs an "H" level signal if the answer is affirmative. An AND circuit 802 outputs an AND of the output signal from the Ne determining unit 801 and the inversion of the operation mode signal S301. An AND circuit 803 outputs an AND of the output signal from the Ne determining unit 801 and the operation mode signal S301.
[0075]
A lighting/dimming switching unit 804 outputs an "H" level signal if the output signal from the AND circuit 802 is at

level, while it outputs a pulse signal with a duty ratio of 50% if the output signal from the AND circuit 802 is at "L" level. A lighting/multi-stage dimming switching unit 805 outputs an "H" level signal if the output signal from the AND circuit 803 is at "H" level, while if the output signal from the AND circuit 803 is at "L" level, the lighting/multi-stage dimming switching unit 805 counts the duration of "L" with use of a timer 805a and outputs a pulse signal having a duty ratio which decreases stepwise in accordance with the duration. In this embodiment, the duty ratio is decreased from 95% to 50% stepwise in one second. According to such a stepwise dimming method, the light quantity decreases in an instant and linearly, so that power saving and the maintenance of high commerciality are attained. [0076]
According to such a headlight control, as shown in Fig. 13, in the "start & idle SW mode" the headlight is turned ON or dimmed in accordance with the engine speed Ne, while in the "stop/start mode" the headlight is turned ON or dimmed stepwise in accordance with the engine speed Ne. Thus, discharge of the battery can be suppressed during stop of the vehicle while ensuring high visibility from an oncoming vehicle . Asaresult, in subsequent starting it is possible to decrease the amount of charge from the generator to the battery, that is, the electric load on the generator decreases, so that the acceleration performance in starting is improved.
[0077]
In the bistarter control section 900, a detection signal provided from the water temperature sensor 155 is inputted to

31

a water temperature determining unit 901. If the water temperature is not lower than a first predetermined value (50 °C in this embodiment) , the water temperature determining unit 901 outputs an "H" level signal to close the bistarter relay, while when the water temperature becomes not higher than a second preset value (10'C in this embodiment), the water temperature determining unit 901 outputs an "L" level signal to open the bistarter relay 164.
[0078]
According to such a bistarter control, fuel becomes rich as the water temperature rises and becomes lean automatically as the water temperature drops. In this embodiment, moreover, since the opening/closing temperature of the bistarter relay 164 is given hysteresis, it is possible to prevent unnecessary opening/closing motions of the bistarter relay 164 which occur in the vicinity of a critical temperature.
[0079]
In the charging control section 500 shown in Fig. 11, a detection signal provided from the vehicle speed sensor 155 and a detection signal from the throttle sensor 257 are inputted to an accelerating operating detecting unit 502, and as shown in Fig. 14, when the vehicle speed is higher than zero and the throttle valve is opened from fully closed to fully open condition within 0.3 second, the accelerating operation detecting unit 502 judges that an accelerating operation has been done, and produces an acceleration detection pulse.
[0080]
In response to the acceleration detection pulse signal

a charging-in-acceleration limiting unit 504 controls the regulator rectifier 167 and causes the charging voltage of the battery 168 to drop from normal 14.5V to 12.0V.
[0081]
Further, the charging-in-acceleration limiting unit 504 starts a timer 504a for 6 seconds in response to the acceleration detection pulse, then upon lapse of the time set to the timer 504a or when the engine speed Ne has increased to a preset number of revolutions or higher or when the throttle valve opening decreases, the limitation on the charging is cancelled and the charging voltage is returned from 12.0V to 14.5V.
[0082]
To an accelerating operation detecting unit 503 are inputted detection signals from the vehicle speed sensor 255, Ne sensor 153 and throttle sensor 257. As shown in Fig. 14, if the throttle valve is open when the vehicle speed is zero and the engine speed Ne is not higher than a preset number of revolutions (2500 rpm in this embodiment), the accelerating operation detecting unit 503 judges that an accelerating operation has been performed, and produces a starting detection pulse.
[0083]
Upon detection of the starting detection pulse the charging-in-start limiting unit 505 controls the regulator rectifier 167 to let the charging voltage of the battery 168 drop from normal 14.5V to 12.0V.
tarts a timer 505a for 7 seconds in response to the starting detection pulse, and upon lapse of the time set to the timer 505a or when the engine speed Ne becomes a preset number of revolutions or higher or when the throttle valve opening decreases, the limitation on the charging is cancelled and the charging voltage is returned from 12.0V to 14.5V.
[0085]
According to such a charging control, when the vehicle driver opens the throttle valve suddenly to make rapid acceleration or upon starting from a stopped state of the vehicle, the charging voltage is kept low and an electric load on the generator 172 is diminished temporarily, so that a mechanical load on the engine 200 is reduced and the acceleration performance is improved.
[0086]
At a timing at which the vehicle driver can start the engine experientially with the starter switch, the after-stop non-sitting control section 100 shown in Fig. 12 permits exceptionally the engine starting with the starter switch 258.
[0087]
An AND circuit 102 calculates the AND of the operation mode signal S301 and the inversion of an output signal from the sitting switch 254 and outputs the AND. If "H" level of the AND circuit 102 is detected for a predetermined time or longer after automatic stop of the engine, that is, if a non-sitting condition of the vehicle driver continues for a predetermined time or longer after automatic stop of the engine in the "stop/start mode", a non-sitting continuance determining unit

101, which is provided with a timer 101a, sets the output signal to "H" level. As a result, the ignition controller 161 is energized, assuming an ignition permitted state. [0088]
An OR circuit 103 calculates and outputs the OR of output signals from the starter switch 258 and the throttle switch 257. An AND circuit 104 calculates the AND of output signals from the non-sitting continuance determining unit 101 and the OR circuit 103 and outputs it to the starter relay 162. More specifically, if a non-sitting condition of the vehicle driver continues for a predetermined time or longer ("H" level output of the non-sitting continuance determining unit 101) after automatic stop of the engine in the "stop/start mode" and if the starter switch 258 is turned ON or the throttle valve is opened thereafter, the starter relay 162 is energized to turn ON the starter motor 171. At this time, since the ignition controller 161 is energize by the non-sitting continuance determining unit 101, it is possible to start the engine.
[0089]
According to such an after-stop non-sitting control, if a non-sitting condition of the vehicle driver is detected continuously for a predetermined time, even after the engine has been stopped in response to a predetermined stop condition, starting of the engine with the starter switch 258 is permitted exceptionally. Therefore, even if the engine is stopped automatically to stop the vehicle and the vehicle driver leaves the vehicle without turning OFF the main power supply and even if the driver when returned to the vehicle operates the starter

switch 258, forgetting that the vehicle is under automatic engine stop control, it is possible to start the engine in the same way as in the normal condition.
[0090]
In the above after-stop non-sitting control, the starting of the engine with the starter switch 258 is permitted exceptionally on condition that a non-sitting condition of the driver has continued for a predetermined time or longer after automatic engine stop in the "stop/start mode", but as indicated with a broken line in Fig. 12, a modification may be made such that the starting of the engine with the starter switch 258 may be permitted by controlling the operation switching section 300 and thereby switching the operation mode from "stop/start mode" to "start & idle SW mode." Or as described "Condition 5" in Fig. 15, by turning OFF the main switch 173, the starting of the engine with the starter switch 258 may be substantially permitted.
[0091]
Fig. 3 is a sectional view of a swing unit according to a second embodiment of the present invention, in which the same reference numerals as in the previous embodiment represent the same or equivalent portions.
[0092]
In the previous first embodiment the sprocket 58 connected to the starting motor 49 is connected to the outer rotor 42 of the generator 44 through the one-way clutch 50, but in this second embodiment the sprocket 58 is connected to the crank shaft 12 through a one-way clutch 50 having the same function as above

and at a position between the pulley 83 and the main bearing 10 both located on the side opposite to the generator 44 with respect to the crank chamber 9.
[0093]
The one-way clutch 50 is made up of one sleeve 57b fixed onto the crank shaft 12, the other sleeve 55b which supports the sprocket 58 rotatably with respect to the crank shaft 12, and a clutch portion 56b which couples the sleeves 55b and 57b so as to inhibit the crank shaft 12 from idling in the reverse direction relatively with respect to the sprocket 58 and permit idling of the crank shaft in the reverse direction.
[0094]
According to this embodiment, since the sprocket 58 for transmitting the driving force of the starting motor 49 to the crank shaft 12 is disposed on the pulley 83 side of the automatic transmission with respect to the crank chamber 9 and the crank length on the automatic transmission side with respect to the crank chamber 9 is set larger than its length on the generator side, the center of the engine can be positioned at the tire center, i.e., the center of the vehicle. Consequently, the swing unit 17 is difficult to undergo twist or moment, the weight distribution is improved and so is the traveling stability.
[0095]
According to this embodiment, moreover, since the sprocket 58 connected to the starting motor 49 is connected to the crank shaft 12 at a position spaced away from the tire 21 axially of the crank shaft, the sprocket 58 can be made large in diameter and a large reduction ratio is obtained, so that

t is possible to reduce the size and weight of the starting motor 49.
[0096]
Fig. 4 is a sectional view of a swing unit 17 according to a third embodiment of the present invention, in which the same reference numerals as in the previous embodiments represent the same or equivalent portions.
[0097]
In this third embodiment, a crank shaft-side sleeve 57c of the one-way clutch 50 is formed integrally on the rear side of the fixed pulley piece 83a, i.e., the side not abutted against the V belt 82, while another sleeve 55c is fixed to a flange portion 83d which is extended axially outwards of the fixed pulley piece 83a, whereby the sprocket 58 is connected to an end portion of the crank shaft 12 through the one-way clutch 50 and the fixed pulley piece 83a.
[0098]
According to this embodiment, since the sprocket 58 and the chain 40 entrained thereon are mounted at the outermost end of the crank shaft 12, their mounting and removal can be done easily and it becomes easy to effect maintenance. Besides, the mounting of an existing swing unit after remodeling also becomes very easy.
[0099]
Further, also in this embodiment, like the second embodiment, the sprocket 58 is connected to the crank shaft 12 at a position spaced away from the tire 21 axially of the crank shaft, so that it becomes possible to increase the diameter of

he sprocket 58 and a large reduction ratio is obtained, thus permitting the reduction in size and weight of the starting motor 49.
[0100]
Fig. 6 is a sectional view of a principal portion of a swing unit 17 according to a fourth embodiment of the present invention and Fig. 7 is a sectional view of the swing unit 17 taken along a plane perpendicular to the crankshaft 12, in which the same reference numerals as in the previous embodiments represent the same or equivalent portions.
[0101]
In the previous first to third embodiments the sprocket 58 mounted on the crank shaft 12 and the starting motor 58 are connected together through the chain 40. On the other hand, in this fourth embodiment, the sprocket 58 and the starting motor 49 are normally connected together through a gear train, and the crank shaft 12 and the sprocket 58 are connected together through the one-way clutch as in the previous embodiment, whereby the transmission of power from the crank shaft 12 side to the starting motor 49 side is cut off without using a sliding pinion. Thus, since one-way connection from the starting motor to the crank shaft can be done without using a sliding pinion, it becomes possible to reduce the engine starting noise.
[0102]
In Figs. 6 and 7, gear teeth 221 are formed on the rotary shaft of the starting motor 49 and a large-diameter gear 222, which is connected to a drive shaft 234, is in mesh with the gear teeth 221. Further, on the drive shaft 234 is formed a

39

small-diameter gear 223 coaxially with and adjacent the large-diameter gear 222 and the sprocket 58 on the crank shaft 12 is engaged with the small-diameter gear 223.
[0103]
For preventing the increase of noise caused by sliding wear or by abrasive wobbling in the engine starting system involving a high engine starting frequency, the drive shaft 234 is supported rotatably by a pair of oil - retaining bush type bearings 234a and 234b at both side portions with the large-and small-diameter gears 222, 223 therebetween. In this embodiment, for suppressing noise generated from the above gear train, the gear teeth meshing with each other are subjected to shaving or polishing.
[0104]
In this embodiment a sliding pinion is not adopted for connection between the sprocket 58 mounted on the cranks haft 12 and the starting motor 49, but both are connected together constantly using a fixed gear train, it becomes necessary to separately provide a configuration for one-way connection which permits the transfer of power from the starting motor 49 side to the crank shaft 12 side but inhibits the power transfer from the crank shaft 12 side to the starting motor 49 side. In this embodiment, therefore, the sprocket 58 is connected to the crank shaft 12 through the one-way clutch 50 as in the previous embodiment.
[0105]
Accordingly, when the starting motor 49 is driven at the time of starting the engine and the sprocket 58 is rotated

the forward direction of the crank shaft 12, the crank shaft is also rotated in the forward direction, following the rotation of the sprocket 58. After start-up of the engine, the crank shaft 12 idles with respect to the sprocket 58 even if the starting motor 49 turns OFF and therefore the driving force of the crank shaft is not transmitted to the starting motor 49.
[0106]
According to this embodiment, as set forth above, since the starting motor 49 and the crank shaft 12 can be connected together without using a sliding pinion, there does not occur an operation noise of sliding pinion and the engine starting noise can be so much kept lower.
[0107] [Effect of the Invention]
The following effects are attained by the present invention.
[0108]
(1) According to the invention defined in claim 1, since the
starting motor can be driven for the reference time or longer
even when the starting operation for driving the starting motor
is performed for only a short time, it is possible to prevent
the occurrence of kick-back caused by a short operation time
of the starting motor and hence possible to reduce the engine
starting noise.
[0109]
(2) According to the invention defined in claim 2, when the
vehicle driver wants to drive the starting motor long of the
driver's own will, it is possible to do so.

[0110]
(3) According to the invention defined in claim 3, in a vehicle
wherein a starting motor is started with a starter switch, it
is possible to prevent the occurrence of kick-back at the time
of starting the engine and thereby reduce the engine starting
noise.
[0111]
(4) According to the invention defined in claim 4, in a vehicle
equipped with an automatic engine stop/start system, it is
possible to prevent the occurrence of kick-back at the time of
starting the engine and thereby reduce the engine starting
noise .
[0112]
(5) According to the invention defined in claims 5 and 6, the
piston which has stopped before the top dead center in explosion
can be moved up to a position exceeding the top dead center in
explosion which follows immediately and also exceeding the next
top dead center in explosion, thus making it possible to
positively prevent the occurrence of kick-back at the time of
starting the engine.
42

We claim:
1. A 4 cycle engine starting system wherein a starting motor is driven
in response to an engine starting operation, the engine starting
system comprising;
a start signal generating means which generates a start signal corresponding to the period of the starting operation;
characterized in that a start signal extending means which extends a start signal shorter than a predetermined reference time to the predetermined reference time or longer and outputs the thus-extended signal;
the start signal extending means extends the start signal in such a manner that a piston when stopped just before an explosive top dead center is moved up to a position which exceeds an explosive top dead center just thereafter and the next explosive top dead center; and
a drive means which drives the starting motor in accordance with an output signal provided from the start signal extending means.
2. An engine starting system as claimed in claim 1, wherein when a start signal longer than the predetermined reference time is inputted, the start signal extending means outputs the inputted start signal as it is without extending it.
3. An engine starting system as claimed in claim 1 or claim 2, comprising a starter switch for driving the starting motor, and wherein the start signal generating means generates the start signal for only an ON period of the starter switch.
-44-

4. An engine starting system as claimed in claim 3, comprising an automatic stop/start system which stops the engine in response to predetermined stop conditions during travel of a vehicle and which, after the stop, restarts the engine in response to a throttle valve opening operation, and wherein the start signal generating means generates the start signal only for the ON period of the starter switch or for the period of the throttle valve opening operation.
5. An engine starting system as claimed in any of claims 1 to 4, wherein the start signal extending means extends the start signal in such a manner that a piston is moved up to a position which exceeds an explosive top dead center just after explosion in a cylinder with the piston fitted therein.
6. An engine starting system substantially as herein described with reference to the accompanying drawings.
Dated this 19/06/2001
[VARUN SHARMA]
OF REMFRY & SAGAR
ATTORNEY FOR THE APPLICANT]

Documents:

565-mum-2001-abstract(16-05-2008).doc

565-mum-2001-abstract(16-05-2008).pdf

565-mum-2001-cancelled pages(19-06-2001).pdf

565-mum-2001-claims(granted)-(16-05-2008).doc

565-mum-2001-claims(granted)-(16-05-2008).pdf

565-mum-2001-correspondence(10-06-2005).pdf

565-mum-2001-correspondence(ipo)-(11-06-2007).pdf

565-mum-2001-drawings(16-05-2008).pdf

565-mum-2001-form 1(16-05-2008).pdf

565-mum-2001-form 18(10-06-2005).pdf

565-mum-2001-form 2(granted)-(16-05-2008).doc

565-mum-2001-form 2(granted)-(16-05-2008).pdf

565-mum-2001-form 3(16-05-2008).pdf

565-mum-2001-form 3(19-06-2001).pdf

565-mum-2001-form 5(19-06-2001).pdf

565-mum-2001-petition under rule 137(27-05-2008).pdf

565-mum-2001-petition under rule 138(27-05-2008).pdf

565-mum-2001-power of attorney(16-05-2008).pdf

565-mum-2001-power of attorney(21-11-2001).pdf

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Patent Number

220715

Indian Patent Application Number

565/MUM/2001

PG Journal Number

33/2008

Publication Date

15-Aug-2008

Grant Date

03-Jun-2008

Date of Filing

19-Jun-2001

Name of Patentee

HONDA GIKEN KOGYO KABUSHIKI KAISHA

Applicant Address

1-1 MINAMIAOYAMA 2-CHOME, MINATO-KU, TOKYO

Inventors:

#	Inventor's Name	Inventor's Address
1	MAKOTO ISHIZUKA	C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA
2	HITOSHI KUROSAKA	C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA
3	YUJI ONO	C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA,

PCT International Classification Number

F02D17/00F02N11/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2000-198052	2000-01-30	Japan