Title of Invention

AN AUTOMATIC STOP-AND-GO SYSTEM FOR A VEHICLE ENGINE

Abstract

To enable simplification of an operation performed by the driver and smooth start of running, in a system capable of automatic stopping and automatic going after the automatic stopping of an engine including a staged transmission provided with an automatic centrifugal clutch. A fully closed signal of throttle, a vehicle stop signal indicating zero vehicle velocity, and a low-speed gear signal indicating that a gear position sensor is on the low-speed side are inputted to a timer 120. The timer 120 energizes an engine stopping portion 121 when each of the signals is maintained up to a time up. On the other hand, an open signal of throttle, the vehicle stop signal, the low-speed gear signal, and a clutch off signal are inputted to a timer122. The timer 122 energizes an engine going portion 123 when each of the signals is maintained up to a time-up. Thus, automatic stopping and automatic going can be performed only when the transmission is on the low-speed side.

Full Text

FORM 2 THE PATENTS ACT 1970 [39 OF 1970] THE PATENTS RULES, 2003 COMPLETE SPECIFICATION [See Section 10; rule 13] "An automatic stop-and-go system for a vehicle engine" HONDA GIKEN KOGYO KABUSHIKI KAISHA, a corporation of Japan, having a place of business at 1-1 Minamiaoyama 2-chome, Minato-ku, Tokyo, Japan. The following specification particularly describes the invention and the manner in which it is to be performed: 13-03-2008 [Detailed Description of the Invention] [0001] [Technical Field to Which the Invention Pertains] The present invention relates to an automatic stop-and-go system for a vehicle engine, and particularly to an automatic stop-and-go system for a vehicle engine by which the engine connected to a staged transmission provided with an automatic centrifugal clutch can be automatically stopped at the time of idle rotation. [0002] [Prior Art] There is a case where a so-called idle stop control is carried out in which, in order to improve fuel consumption of an internal combustion engine, the engine is stopped by automatically stopping the supply of a fuel at the time when the vehicle is stopped and thereafter the engine is restarted when a predetermined condition for going is established. [0003] On the other hand, there is a case where the rotation of the engine is transmitted to driving wheels through an automatic centrifugal clutch and a staged transmission. The automatic centrifugal clutch is disconnected below a predetermined engine rotational speed and is connected above the predetermined engine rotational speed, with the predetermined engine rotational speed as a criterion. In the vehicle provided with the automatic centrifugal clutch, ON-OFF operations of the clutch are unnecessary, which is excellent in view of facilitating the operation of the vehicle. As one example of such automatic centrifugal clutch, there is known the one described in Japanese Utility Model Publication No. Sho 59-28132. [0004] [Problem to Be Solved by the Invention] In the case of adopting the idle stop control for a vehicle provided with the above-mentioned automatic 3 centrifugal clutch, the following inconveniences might be generated. Namely, in the vehicle provided with the automatic centrifugal clutch, the clutch is disconnected automatically when the engine rotational speed is lowered, so that the idle stop, namely, engine stoppage may occur in the condition where the transmission is changed over to a high-speed stage. Since the driving force is low when the transmission is on the high-speed side, restarting (going) of the engine in this condition may lead to that the driving force for going (starting of running) is insufficient, resulting in that smooth going (starting of running) of the vehicle is hampered. [0005] It is an object of the present invention to solve the above-mentioned problem and to provide an automatic stop-and-go system for a vehicle engine connected to a staged transmission provided with an automatic centrifugal clutch by which the engine can be automatically stopped and let go in the condition where smooth going performance is secured. [0006] [Means for Solving the Problem] In order to attain the above object, the present invention is characterized firstly in that, in an 4 automatic stop-and-go system for a vehicle engine connected to a staged transmission through an automatic centrifugal clutch, the automatic stop-and-go system includes throttle detection means for outputting a fully closed signal when throttle opening is fully closed; vehicle velocity detection means for outputting a vehicle stop signal when vehicle velocity is zero; and gear position detection means for outputting a low-speed gear signal when the staged transmission has been changed over to a predetermined low-speed position, wherein the engine in operation is automatically stopped when all of the fully closed signal, the vehicle stop signal and the low-speed gear signal are being outputted. [0007] In addition, the present invention is characterized secondly in that clutch detection means for outputting a clutch OFF signal when the automatic centrifugal clutch is OFF is further provided, a function of outputting an open signal when a throttle is open is added to the throttle detection means, and the engine is let go when all of the open signal, the clutch OFF signal and the low-speed gear signal are being outputted. [0008] In the present invention, according to the first 5 characteristic feature, the engine is automatically stopped when the vehicle has been stopped, the throttle has been closed and the transmission is in the low-speed position, so that the condition for going is satisfied immediately in the invention according to the second characteristic feature. Besides, since going and starting running can be performed directly from the low-speed gear where the driving force is high, smooth going (starting of running) can be achieved. [0009] Further, the present invention is characterized thirdly in that the engine in operation is automatically stopped when all of the fully closed signal, the vehicle stop signal and the low-speed gear signal have been outputted continuously for a predetermined period of time. According to the third characteristic feature, the engine is stopped or let go when the condition for stopping or going is securely established. [Brief Description of the Drawings] [Fig. 1] Fig. 1 is a block diagram showing the functions of a major part of an automatic stop-and-go system according to one embodiment of the present invention. [Fig. 2] Fig. 2 is a block diagram showing a hardware constitution of the automatic stop-and-go system according to one embodiment of the present invention. [Fig. 3] Fig. 3 is a flow chart for automatic stopping of engine. [Fig. 4] Fig. 4 is a flow chart for automatic going of engine. [Fig. 5] Fig. 5 is a sectional view of a staged transmission including a position sensor. [Mode for Carrying Out the Invention] Now, one embodiment of the present invention will be described below referring to the drawings. Fig. 2 is a block diagram showing the system constitution of an automatic stop-and-go system for engine according to one embodiment of the present invention. In the figure, a vehicle velocity sensor 103, a throttle sensor 104, a gear position sensor 105 and a clutch sensor 106 are connected to an ECU 100 through an input port 102. The vehicle velocity sensor 103 may include, for example, a Hall sensor for detecting the number of teeth of a gear connected to driving wheels not shown and generating a pulse signal, and the ECU 100 has the function of counting the pulse signal and calculating the vehicle velocity. The throttle sensor 104 may include a potentiometer connected to and turned by a rotary shaft of a throttle valve provided in an intake pipe not shown, and the ECU 100 has the function of performing A/D conversion on an analog value outputted from the throttle sensor 104 and calculating the throttle opening from the digital value thus obtained. [0011] The gear position sensor 105 may include a change switch which is provided on a shaft of a shift drum of a transmission described later and generates a signal according to the gear position (speed change ratio), and the ECU 100 has the function of judging the gear stage based on a signal outputted from the change switch. Namely, the ON/OFF conditions of contacts provided for each gear stage for detection of gear position are detected at a port of the ECU 100, and the gear position is detected. [0012] The clutch sensor 106 is provided in the inside of an automatic centrifugal clutch so as to be able to detect the ON/OFF of the clutch, and outputs a clutch OFF signal when the clutch sensor has been changed over to the OFF side of the clutch. [0013] On the other hand, an ignition coil 109 is connected to an output port 107 of the ECU 100 through an ignition controller 108. The ignition coil 109 follows an instruction from the ECU 100, and passage of a primary-current for the ignition coil is started. Further, a starter motor (hereinafter referred to simply as "starter") 111 is connected to the output port 107 through a motor driver 110. The motor driver 110 follows an instruction from the ECU 100, and energizes the starter 111, thereby turning a crank shaft of the engine. When a predetermined engine stopping condition or going condition according to the vehicle velocity, the throttle opening and the gear position and the like is satisfied, the ignition coil 109 and the starter 111 are driven in accordance with each of the conditions. The automatic stop-and-go control for the engine by driving of the ignition coil 109 and the starter 111 will be further described later. [0014] Fig. 5 is a sectional view showing the constitution of a major part of a transmission including the gear position sensor 105. In the figure, a first-stage shaft 13 is supported on crankcases 20, 21 through bearings 14, 15. The first-stage shaft 13 is connected to the engine through an automatic centrifugal clutch not shown. The shaft 13 is provided with a gear 16 formed as one body with the shaft 13, gears 17 and 18 rotatable relative to the shaft 13, and a gear 19 disposed between the gears 17 and 18, slidable in the axial direction of the shaft 13 and spline-connected to the shaft 13 so that it can be rotated as one body with the shaft 13 in the rotating direction. [0015] A second-stage shaft 22 is supported on the crankcases 20, 21 through bearings 23, 24. The shaft 22 is provided with gears 25, 26 rotatable relative to the shaft 22, a gear 27 spline-connected to the shaft 22 so as to be capable of rotation as one body with the shaft 22 and positionally restricted in the axial direction, and a gear 28 slidable in the axial direction of the shaft 22 and spline-connected to the shaft 22 so as to be rotated as one body with the shaft 22 in the rotating direction. [0016] The shift drum 1 is rotatably supported by a structure in which the outer circumference of one end thereof and the outer circumference of a boss la at the other end thereof are fitted in the crankcases 20, 21. Two shift forks 29, 30 are fitted to the shift drum 1. Hubs 29a, 30a of the shift forks 29, 30 are provided with guide rods 31, 32 whose tip ends project to the side of the shift drum 1 to be engaged with guide grooves 33, 34 provided at the outer circumference of the shift drum 1. A stop pin 35 and an arm 36 are provided so that the guide rods 31, 32 are not disengaged from the shift forks 29, 30. [0017] The guide grooves 33, 34 have gradients so as to deviate the shift forks 29, 30 by predetermined amounts in the axial direction in response to one rotation of the shift drum 1. Namely, the shift drum 1 constitutes a cylindrical cam, and the guide rods 31, 32 as cam followers are engaged with the cam grooves 33, 34, so that the shift forks 29, 30 are deviated by predetermined amounts in response to the rotation of the cam. [0018] The pin 3 5 and the arm 3 6 are engaged with one end of the shift drum 1, and the arm 36 obtains a driving force from a motor not shown, to turn the shift drum 1. A plate 8 is fixed to an end portion of the shift drum 1, and a stopper roller 9 provided at an arm 10 is engaged with a recessed portion provided at the outer circumference of the plate 8, whereby the shift drum 1 is maintained at a predetermined angle. Tip ends of the shift forks 29, 30 are engaged with grooves 28a, 19a provided in the circumferential direction of the gear 28 and the gear 19. Therefore, when the shift drum 1 is turned, the gear 28 and the gear 19 are deviated in the axial direction of the shafts 13, 22 according to the turning direction and the turning amount. [0019] Dowels 28b, 28c to be engaged with the gears 25, 26 are provided on side surfaces of the gear 28, and the gear 28 is connected to either one of the gears 25 and 26 according to the deviation direction. On the other hand, side surfaces of the gear 19 is provided with a slit 19b and a slit 19c to be engaged with the gears 17 and 18, and the gear 19 is connected to either one of the gear 17 and the gear 18 according to the deviation direction. [0020] The first-stage shaft 13 is connected to a crank shaft not shown, and transmits the rotation of the engine to the second-stage shaft 22 at a speed reduction ratio according to the combination of the gears. A sprocket 37 is fixed to the second-stage shaft 22, and the rotation of the shaft 22 is transmitted to a driving wheel not shown through a chain 38. [0021] The gear position sensor 105 is disposed on the other end side of the shift drum 1. The gear position sensor 105 is constituted as follows. A base plate 40 having a contact plate 39 is fixed by a bolt 41 to a boss la formed at the other end of the shift drum 1. On the other hand, a boss 43a of a switch block 43 is fitted in a space 42 of the crankcase 20 in which the contact plate 39 and the base plate 40 are contained, and the switch block 43 is fixed to the crankcase 20 by a bolt 44. An 0-ring 45 is provided at a spigot joint portion of the switch block 43 and the crankcase 20. [0022] Of the switch block 43, a surface opposed to the contact plate 39 is provided with a plurality of fixed contacts (not shown), and when a contact provided on the contact plate 39 and the fixed contact make contact with each other, a gear position detection signal is outputted to the ECU 100 through a lead wire 12. For example, the switch block 43 is provided with five fixed contacts correspondingly to the position of the shift drum 1 according to the speed change ratio. [0023] Fig. 3 is a flow chart for automatic stopping of the engine. In step SI, a detection signal from the throttle sensor 104 is read in, and whether or not a throttle valve is closed is decided based on whether or not the throttle opening is not more than a predetermined angle. When the throttle valve is closed, step S2 is entered, in which a detection signal from the vehicle velocity sensor 103 is read in, and it is decided whether or not the vehicle velocity is zero, namely, whether or not the vehicle is at stop. [0024] When the vehicle velocity is zero, step S3 is entered, in which an output from the gear position sensor 105, namely, a gear position detection signal is read in, and it is decided whether or not the transmission has been changed over to a low-speed (first speed or second speed) position. When the transmission is in the low-speed position, step S4 is entered, in which the engine is stopped. In addition to the decision of each condition in the steps SI to S3, a process (step S3') for proceeding to step S4 when the condition has been continued for a predetermined period of time may be added. When any one of the decisions in the steps SI to S3 and the step S3' is NO, step S4 is skipped, so that the automatic stopping of the engine is not carried out. [0025] The engine stopped by the process of step S4 as described above is restarted by the following process. Fig. 4 is a flow chart for automatic going of the engine. In step S10, a detection signal from the throttle sensor 104 is read in, and it is decided whether or not the throttle valve is open based on whether or not the throttle opening is not less than a predetermined angle. When the throttle valve is open, step Sll is entered, in which the gear position detection signal is read in, and it is decided whether or not the transmission has been changed over to the low-speed position. When the transmission is in the low-speed position, the engine is let go. Also in the decision of whether or not the going is to be carried out, in the same manner as in the case of decision of whether or not the engine is to be stopped, in addition to the decision of each condition in the steps SIO to Sll, a process (step Sll') for proceeding to step S12 when the condition has been continued for a predetermined period of time may be added. When any one of the decisions in the steps SIO and Sll and step Sll1 is NO, step S12 is skipped, so that automatic going of the engine is not carried out. Incidentally, it is desirable to include a clutch OFF signal from the clutch sensor 106 into the condition for the automatic going. [0026] Fig. 1 is a block diagram showing the functions of a major part of an automatic stop-and-go system for engine according to the present invention. The throttle sensor 104 outputs a fully closed signal when the throttle opening is nearly zero, namely, smaller than a predetermined minute opening, and outputs an open signal when the throttle opening is greater than the minute opening. The vehicle velocity sensor 103 outputs a vehicle stop signal when the vehicle velocity is nearly zero. The gear position sensor 105 outputs a low-speed gear signal when the changed-over position of the transmission is on a predetermined low-speed side (for example, first speed or second speed). The clutch sensor 106 outputs a clutch OFF signal when the automatic centrifugal clutch is turned OFF. The fully closed signal, the vehicle stop signal and the low-speed gear signal are inputted to a timer 120. The timer 120 comes to a time-up when the fully closed signal, the vehicle stop signal and the low-speed gear signal have been continued for the lapse of a predetermined time set in the timer 120, and an engine stopping portion 121 is energized in response to the time-up. An ignition controller 108 follows an instruction from the engine stopping portion 121, and stops the supply of current to the primary side of the ignition coil 109. By this, ignition is stopped, whereby the engine is automatically stopped. [0027] On the other hand, the open signal, the vehicle stop signal, the low-speed gear signal and the clutch OFF signal are inputted to a timer 122. The timer 22 comes to a time-up when the open signal, the vehicle stop signal, the low-speed gear signal and the clutch OFF signal have been continued for the lapse of a predetermined time set in the timer 122, and an engine going portion 123 is energized in response to the time-up. The ignition controller 108 follows an instruction from the engine going portion 123, and starts the supply of current to the primary side of the ignition coil 109. In addition, the motor driver 110 follows an instruction from the engine going portion 123, and drives the starter 111. By this, automatic going of the engine is carried out. Incidentally, the timer 120 and the timer 122 may be provided selectively. They may be omitted, and the decision for stopping and going may be carried out by inputting each of the signals directly to the engine stopping portion 121 and the engine going portion 122, as has been described above with reference to Figs. 3 and 4. [0028] [Effect of the Invention] As is clear from the above description, according to the inventions as set forth in claims 1 to 3, automatic stopping and automatic going of the engine can be carried out only in the case where the gear position is low-speed position. Therefore, in the going (restarting) of the engine after automatic stopping, the going can be performed swiftly by only opening the throttle, and the start of running of the vehicle can be made smoothly at a low-speed gear where the driving force is high. WE CLAIM: 1. An automatic stop-and-go system for a vehicle engine connected to a staged transmission through an automatic centrifugal clutch, comprising: throttle opening detecting means (104) for outputting a fully closed signal when throttle opening is fully closed; vehicle velocity detection means (103) for outputting a vehicle stop signal when vehicle velocity is zero; and gear position detection means (105) for outputting a low-speed gear signal when said staged transmission has been changed over to a predetermined low-speed position, wherein said engine in operation is automatically stopped when all of said fully closed signal, said vehicle stop signal and said low-speed gear signal are being outputted. 2. An automatic stop-and-go system for a vehicle engine as claimed in claim 1, further comprising clutch OFF signal detecting means (106) for outputting a clutch OFF signal when said automatic centrifugal clutch is OFF, wherein a function of outputting an open signal when a throttle is open is added to said throttle opening detecting means (104), and wherein said engine starts when all of said open signal, said clutch OFF signal and said low-speed gear signal are being outputted. 3. An automatic stop-and-go system for a vehicle engine as claimed in claim 1, wherein said engine in operation is automatically stopped when all of said fully closed signal, said vehicle stop signal and said low-speed gear signal have been outputted continuously for a predetermined period of time. 4. An automatic stop-and-go system for a vehicle engine substantially as herein described with reference to the accompanying drawings. Dated 3rd day of April, 2002. [RAJAN AILAVADI] Of Remfry & Sagar Attorney for the applicants ^

Documents:

316-mum-2002-abstract(13-03-2008).doc

316-mum-2002-abstract(13-03-2008).pdf

316-mum-2002-cancelled pages(13-03-2008).pdf

316-mum-2002-claim(granted)-(13-03-2008).doc

316-mum-2002-claim(granted)-(13-03-2008).pdf

316-mum-2002-corrospondence(13-03-2008).pdf

316-mum-2002-corrospondence(ipo)-(25-04-2008).pdf

316-mum-2002-declaration certificate(13-03-2008).pdf

316-mum-2002-drawing(13-03-2008).pdf

316-mum-2002-form 1(13-03-2008).pdf

316-mum-2002-form 13(13-03-2008).pdf

316-mum-2002-form 18(03-03-2006).pdf

316-mum-2002-form 2(granted)-(13-03-2008).doc

316-mum-2002-form 2(granted)-(13-03-2008).pdf

316-mum-2002-form 3(03-04-2004).pdf

316-mum-2002-form 3(12-04-2004).pdf

316-mum-2002-form 5(03-04-2002).pdf

316-mum-2002-petition under rule 137(13-03-2008).pdf

316-mum-2002-petition under rule 138(13-03-2008).pdf

316-mum-2002-power of authority(13-06-2002).pdf

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