Title of Invention

'STARTER PROTECTOR"

Abstract

To reliably activate the engine by keeping the starting motor active while the starter switch is being operated, and to prevent the activation of the starting motor while the engine is in operation or immediately after the engine stops operating. Thus, it is possible to prevent the starter pinion from engaging with the rotating ring gear, and to protect the engine starting system. [Means to solve the problems] When both the starter and stop switches 8 and 9 are turned on, the start relay 10 is activated to supply power to the starting motor 13. The starting motor 13 is kept active until either the switch 8 or 9 is turned off. Thereafter, the output of the pulser 12 is shaped by the waveform shaping circuit 22, and is supplied to the timer .32 as the crank angle signal 22a. The timer 32 keeps the timer output 32a during the operation of the engine or during the timer interval after the engine stops operating. The starting motor 13 is prevented from being restarted by the timer output 32a during the rotation of the crankshaft. [Selected Drawing] Fig.1

Full Text

[Detailed Description of the Invention] [Field of the Invention] The present invention relates to a starter protector for a starting motor used to activate a motorcycle engine or the like, and more particularly to a starter protector which allows reliable activation of the engine by keeping the starting motor active during the operation of a starter switch (start switch) , and prevents the operation of the starting motor during the operation of the engine, or for a predetermined period of time after the engine stops operating, thereby preventing a starter pinion from engaging with a rotating ring gear, and protecting an engine starting system. [Related Art] Japanese Utility Model Laid-Open Publication No. Sho 53-37838 discloses a starter protector, in which once a starter switch is turned off, a starting motor cannot be activated for a predetermined time period. In Japanese Patent Publication No. Sho 53-41300, a starter protector for a vehicle includes: a starter relay having a contact disposed between an auxiliary terminal of a starter, and a coil for operating the contact; a frequency detecting circuit for opening the starter relay when a frequency of an AC voltage input from a generator mounted on a vehicle exceeds a predetermined value; and delay means for controlling an output stage transistor of the frequency detecting circuit in order to keep the starter relay opened for a certain time period after the AC voltage is suspended. Thus, the starter protector enables reliable activation .of the engine, and protects the starter. According to Japanese Patent Publication No. Sho 54-40698, a starter protector for a vehicle includes: a starter relay having a contact disposed between an auxiliary terminal of a starter, and a coil for operating the contact; a frequency detecting circuit for opening the starter relay when a frequency of an AC voltage inputted from a generator mounted on a vehicle exceeds a predetermined value; a starter switch for interrupting a conducting circuit of the coil of the starter relay; a capacitor connected to a non-power source side of the starter switch and the ground; and an electric path for introducing a capacitor voltage to the frequency detecting circuit. The starter protector prevents the operation of the frequency detecting circuit for a certain time period after the starter switch is turned on again. [Problems to be solved by the Invention] In Japanese Utility Model Laid-Open Publication No. Sho 53-37839, once the starter switch is turned off, the starter cannot be activated for the predetermined time period. Therefore, even if the engine could not be activated by previous operation of the starter switch and remains completely inactive, the engine cannot be restarted until a lapse of the predetermined time period. In the starter protectors of the patent publications No. Sho 53-41300 and No. Sho 54-40698, an engine speed is detected on the basis of a frequency of the AC voltage generated by the AC generator, and the engine starting system is disconnected (i.e., the starting motor is stopped ) when the engine speed exceeds a predetermined value. When such a starter protector is applied to a motorcycle, the starting motor will be stopped if the engine speed exceeds the predetermined value during a first combustion stroke and so on. This will adversely affect starting performance of the engine, or irritate a rider to a certain extent. For instance, when the engine is slow to start, it is preferable to reliably activate the engine by intermittently supplying driving force of the starting motor while the starter switch is being operated. However, since the starting motor is stopped on the basis of a detected engine speed (i.e., the detected frequency of the AC voltage) , the driving force of the starting motor cannot be used effectively. The present invention is conceived to overcome the foregoing problems of the related art, and provides a starter protector in which a starting motor is kept active during the operation of a starter switch in order to reliably activate an engine, and the operation of the starting motor is disabled to prevent a starter pinion from engaging with a rotating ring gear during the operation of the engine, or after the engine becomes completely inactive even when the starter switch is operated, thereby protecting the engine starting system. [Means to solve the problems] According to the invention, the starter protector includes : a ring gear fixed to a crankshaft; a starter pinion which is engaged with said ring gear by inertia; a starting motor supplying power to rotate said starter pinion; and a start control unit controlling the operation of said starting motor. The start control unit receives a signal generated in accordance with the rotation of the crankshaft and a starter switch signal, and includes a timer keeping a timer output for a predetermined period of time in response to the rotation of the crankshaft. The starting motor is operated while the starter switch is turned on during the absence of the timer output. The starting motor is kept inactive until the timer output is suspended if the starter switch is turned on during the presence of the timer output. The start control unit is integral with an ignition unit, and uses a signal from an ignition pulser as the signal in accordance with the rotation of the crankshaft. The starter protector allows the operation of the starting motor during the operation of the starter switch when the starter switch is turned on during the absence of a timer output, so that the engine can be reliably started. According to the invention, the starting motor is not allowed to operate even if the starter switch is operated during the operation of the engine, or in a specified time period after the engine is stopped. Therefore, it is possible to prevent the starter pinion from engaging with the rotating ring gear, and protect the engine starting system. The start control unit for controlling the starting motor and the ignition unit for controlling the engine ignition are formed as an integral member, and the signal from the ignition pulser can be used as the signal according to the rotation of the crankshaft. This is effective in making the starter protector compact and in reducing the cost thereof. Accordingly, the present invention relates to a starter protector comprising: a ring gear fixed to a crankshaft; a starter pinion which is engaged with said ring gear by inertia; a starting motor supplying power to move said starter pinion; and a start control unit controlling the operation of said starting motor; characterised in that said start control unit receives a signal produced in accordance with the rotation of the crankshaft and a starter switch signal, and has a timer keeping a timer output for a predetermined period of time in response to the signal produced by the rotation of the crankshaft; said starting motor is operated when said starter switch is turned on during the absence of the timer output; and said starting motor is kept inactive until the timer output is suspended when said starter switch is turned on during the presence of the timer output. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Fig. 1 is a block diagram showing one embodiment of a starting/ignition system to which the starter protector of the invention is applied. Fig. 2 is a block diagram showing another example of the starting/ignition system provided with the starter protector according to the invention. Fig. 3 is a block diagram showing still another example of the starting/ignition system having the starter protector according to the invention. Fig. 4 is a cross sectional view showing the structure of the smarting motor, the starter pinion of the inertia-engaged type, and the ring gear fixed to the crankshaft. • Fig. 5 is a timing chart showing the operation of the start control unit. [Description of Embodiment] An embodiment of the invention will be described with reference to the accompanying drawings. Fig. 1 is a block diagram showing the configuration of a starting/igniting system to which the starter protector according to the invention is applied. Referring to Fig. 1, the starting/igniting system 1 is housed in a CDI unit 2 (capacitor discharge type ignition control unit) together with a start control unit 3, thereby forming an integral unit. The starting/igniting system 1 includes a battery 4, an ACG 5 (AC generator), and REG/REC 6(voltage regulating/ rectifying circuit). The ACG 5 is connected to a crankshaft of an engine (not shown). During the operation of the engine, AC power generated by the ACG 5 is rectified and voltage-regulated by the REG/REC 6, is converted to DC power, charges the battery 4, and is supplied to various loads. The REG/REC 6 includes a reverse flow preventing diode and so on in order to prevent power of the battery 4 from being supplied to the REG/REC 6. The DC power of the battery 4 is supplied via a fuse 7 to a power source circuit 21 in the CDI unit 2, and also to one side of a starter switch 8 and to one side of a stop switch 9. Further, the DC power of the battery 4 is supplied to a contact l0a of a start relay 10. The starter switch 8 is turned on by pressing a start button (not shown) , and remains active while the button is being pressed. Thereafter, the DC power of the battery 4 is supplied to one input terminal of a 2-input AND circuit 3 and one end of . The stop switch 9 is turned on in unison with the braking action. When the stop switch 9 is turned on following the braking action, the DC power of the battery 4 is supplied not only tc the other input terminal of the 2-input AND circuit. 3 of the start control unit 3 but also to a stop light 11. The stop light 11 is lit when the braking action is taking place, thereby visually indicating the braking action. A crank angle of the crankshaft (not shown) of the engine is detected by a pulser 12 (a crank angle sensor). in Fig. 1, the pulser 12 has a pulser coil for detecting a magnetic flux supplied by a magnet fixed at a predetermined position of either the crankshaft or a rotary shaft of the ACG 5. A crank angle detecting signal 12a detected by the pulser 12 is supplied to a waveform shaping circuit 22 in the GDI unit 2. The CDI unit 2 includes a power source circuit 21, a waveform shaping circuit 22, a converter 23, an ignition control, circuit 24, a main capacitor 25, a thyristor (SCR) 26, and a^ start control unit 3. The power source circuit 12 receives the DC power from the battery 4, and the DC power which is generated by the ACG 5 and supplied via the REG/REc 6 during the operation of the engine, thereby generating a circuit power VCC whose voltage is lower than the battery voltage and is stabilized, and supplies it to various circuits. Specifically, the circuit power VCC is supplied to the waveform shaping circuit 22, converter 23, ignition control circuit 24, and starter control circuit" 3. The waveform shaping circuit 22 shapes the crank angle detecting signal 12a from the pulser 12 in order to generate and output a two-level crank angle signal 22a. The crank angle signal 22a is supplied to the ignition control circuit 24 and the start control unit 3. The converter 23 is a booster type DC-DC converter generating and outputting a booster voltage 23a which is much higher than the voltage of the circuit power VCC. The booster voltage 23a from the converter 23 is supplied to the main capacitor 25, and a series circuit constituted by a primary winding 27a of an ignition coil 27, thereby charging the main capacitor 25. The ignition control circuit 24 recognizes the crank angle of the crankshaft on the basis of the crank angle signal 22a from the waveform shaping, circuit 22, recognizes an engine revolution cycle (an engine speed) on the basis of a cycle of the crank angle signal 22a (i.e., the number of crank angle signals 22a generated per unit time), advances or retards ignition timing on the basis of the engine revolution cycle, and generates and outputs a trigger pulse signal 24a at the advanced or retarded ignition timing. The trigger pulse signal 24a is supplied to a gate of the thyristor 26. The thyristor 26 becomes conductive in response to the trigger pulse signal 24a. Following the conduction of the thyristor 26, electric charge in the main capacitor 25 is quickly discharged through a closed loop formed by the primary winding 27a of the ignition coil 27, main capacitor 25, and thyristor 26. A high voltage induced at a secondary winding 27b of the ignition coil 27 is supplied to an ignition plug 28 to ignite the engine. The start control unit 3 includes: a 2-input AND circuit 31 receiving the operation status information of the starter and stop switches 8 and 9 as inputs; a timer 32 activated in response to the crank angle signal 22a; an NPN transistor 33 for inhibiting input of the crank angle signal 22a to the timer 32; an NPN transistor 34 for activating the starter relay 10 in response to an output 32a of the timer 32; an inverter 35 for inverting a loqic level of the timer output 32a; a restart-preventing NPN transistor 36 for preventing the output of the 2-input AND circuit 31 from being supplied to a base of the NPN transistor 33, in response to an output of the inverter 35; and base resistors 37 to 40 of the respective transistors. The timer 32 includes: a quick charge NPN transistor 42 for quickly charging a timer interval setting capacitor 41 in response to the crank angle signal 22a; a discharge resistor 43 juxtaposed with the timer interval setting capacitor 41 in order to determine a time constant of the capacitor 41; and a timer output inverter 44 for producing the two-level timer output signal 32a using a charging voltage of the capacitor 41 as in input. The timer output inverter 44 is a Schmitt trigger type inverter in which input voltage thresholds are different when the output level varies from a low level L to a high level H and when the output level varies from the high level H to the low level L. Referring to Fig. 1, the starting/igniting system 1 is designed to start the engine when both the starter and stop switches 8 and 9 are simultaneously operated, i.e., when the braking operation is in progress. When both the start and stop switch 8 and 9 are turned on, the output of the 2-input AND circuit 31 changes to the high level H. This output is supplied to the base of the timer input preventing NPN transistor 33 via the base resistor 37. During the non-operation of the engine (not shown), the pulser 12 does not output the crank angle detecting signal 12a, so that the waveform shaping circuit 22 does not output the crank angle signal 22a. Since electric charge of the timer interval setting capacitor 41 is discharged via the discharge resistor 43, an input voltage of the timer output inverter 44 is lower than the input voltage threshold, and the timer output signal 32a, i.e., the output of the inverter 44, has the H level. When the timer output signal 32a has the H level, the output cf the inverter 35 becomes the L level, so that the restart preventing NPN resistor 35 is turned off (i.e., becomes non-conductive). Therefore, the base current of the base resistor 37 is supplied to the timer input preventing NPN transistor 33 in accordance with the output of. the 2-input AND circuit 31. The NPN transistor 33 is then turned on (i.e., becomes conductive) . After turning on of the starter switch 8, the DC voltage of the battery 4 is supplied to one end of the exciting winding l0a of the start relay 10 via the starter switch 8. The other end of the exciting winding l0b of the start relay 10 is connected to a collector of the start relay activating NPN transistor 34. When the output signal 32a of the timer 32 has the H level, the base current is supplied to the NPN transistor 34 via the base resistor 39. In this state, the NPN transistor 34 remains conductive, and an exciting current is supplied to the exciting winding lOb of the start relay 10 via a route constituted by the battery 4, fuse 7, starter switch 8, excising winding l0b, and NPN transistor 34, thereby closing the contact lOa of the start relay 10. Following the closure of the contact lOa of the start relay 10, the DC power is supplied from the battery 4 to a starting motor 13 via the contact lOa, thereby activating the starting motor 13. The starting motor 13 is a DC motor. When the starting motor 13 is activated, the starter pinion is engaged with the ring gear fixed to the crankshaft, so that the crankshaft is rotated by the rotating force of the starting motor 13. The rotating position of the crankshaft is then detected by the pulser 12, which outputs the crank angle detecting signal 12a. The waveform shaping circuit 22 shapes the crank angle detecting signal 12a to output the crank angle signal 22a. The ignition control circuit 24 produces a trigger pulse signal 24a in response to the crank angle signal 22a. The crank angle signal 22a from the waveform shaping circuit 22 is supplied to the input of the timer 32 via the base resistor 33. If both the starter and stop switches 8 and 9 are pressed to start the engine, the timer input preventing NPN transistor 33 is kept conductive by the H level output of the 2-input AND circuit 31. Therefore, a base potential of the quick charge transistor 42 in the timer 32 is kept at the L level. In ether words, in the foregoing states of the starter and stop switches 8 and 9, the crank angle signal 22a is not supplied to the timer 32 because of the timer input preventing NPN transistor 33. In this state, the output signal 32a of the timer 32 is kept at the H level, so that the starting motor 13 is being supplied with the power via the start relay 10, and keeps on rotating. Thus, continuous rotation of the starting motor 13 enables the reliable activation of the engine. When the starter switch 8 or the stop switch 9, or both of these switches are turned off while the engine is being started, the output of the 2-input AND circuit 31 becomes the L level to turn off the timer input preventing NPN transistor When the NPN transistor 33 is turned off, the crank angle signal 22a is supplied to the base of the quick charge NPN transistor 42 from the waveform shaping circuit 22 via the base resistor 33. The NPN transistor 42 is then turned on by the base current. Thereafter, the circuit power VCC is supplied to the timer interval setting capacitor 41 via the NPN transistor 42 to quickly charge the capacitor 41. After the capacitor 41 has been quickly charged, the output of the timer output inverter 44 becomes the L level, so that the base current to the start relay activating NPN transistor 34 is interrupted in order to turn off the NPN transistor 34. The current supply to the exciting winding l0b of the start relay 10 is interrupted to open the contact lOa of the start relay 10, and stop current supply to the starting motor 13. The circuit shown in Fig. 1 is designed such that the power is supplied to the exciting winding lOb of the start relay 10. Therefore, when the start switch 8 is turned off, power supply to the exciting winding lOb is interrupted, thereby opening the contact l0a to prevent power supply to the starting motor 13. The timer 32 is designed so as to continue to supply the L level timer output 32a for a predetermined timer interval after the generation of the L level timer output 32a in response to the crank angle signal 22a. The timer interval is approximately several hundred milliseconds (e.g., 0.5 seconds). Therefore, even if the crankshaft rotates very slowly and the crank angle signal 22a has a very long cycle, the timer output signal 32a maintains the L level, and is designed so as to return to the H level in several 100 milliseconds (e.-g., 0.5 seconds) after the crankshaft stops rotating (i.e., the engine stops) and the crank angle signal 22a is not output. When the timer output signal 32a remains at the level, the output of the inverter 35 is at the H level, and the base current is supplied to the restart preventing NPN transistor 36 via the base resistor 40. The NPN transistor 36 then becomes conductive. The NPN transistor 36 then prevents the output of the 2-input AND circuit 31 from being supplied to the timer input NPN transistor 33. Therefore, even when both the starter and stop switches 8 and 9 are operated to restart the engine while the timer output signal 32a remains at the L level (i. e., during the rotation of the crankshaft or after the lapse of the timer interval following the stop of the crankshaft), the starting motor 13 cannot be activated. In the circuit configuration shown in Fig. 1, when the starter switch 8 is turned on while the timer output signal 32a remains at the H level, the start relay 10 is operated to supply the power to the starting motor 13 in order to activate it. The moving output of the starting motor 13 causes the crankshaft to rotate. When the output signal 32a of the timer 32 becomes the L level in response to the crank angle signal 22a, the start relay activating NPN transistor 34 is made non-conductive, which releases the start relay 10, so that power supply to the timer 13 is suspended during the timer interval. However, when the starter switch 8 remains pressed, the current is intermittently supplied to the starting motor 13 in accordance with the timer interval cycle. This means that unnecessary power is consumed, and is not preferable. in. order to overcome this problem, a circuit shown in Fig. 2 is configured as follows. The starter switch 8 is connected in series downstream of the stop switch 9. When both the stop and starter switches 9 and 8 are simultaneously turned on, the power is supplied to the exciting winding l0b of the start relay 10, and the base current is supplied to the timer input preventing NPN transistor 33 via the base resistor 37. Therefore, when only the starter switch 8 is turned on, no power is supplied to the starting motor 13. In the circuit of Fig. 2, the stop and starter switches 9 and 8 are connected in series in order to produce AND outputs for these switches, so that it is possible to delete the 2-input AND circuit 31 shown in .Fig. 1. Fig. 3 is a block diagram showing the configuration of another starting/igniting system having the starter protector according to the invention. A start control unit 30 in Fig. 3 includes a 3-input AND circuit 30A, a retriggerable mono-stable mulitivibrator 308 constituting a timer, and a gate activating circuit 30C. The mono-stable multivibrator 30B outputs via an output terminal 30F an L-level output signal 30f (i.e., a timer output signal) for the predetermined timer interval in response to the crank angle signal 22a supplied to a trigger input terminal 30E when the logic level of a signal supplied to an enable input terminal 30D has the L level. The mono-stable multivibrator 30B is designed such that it keeps on outputting the L-level output signal 30f (timer output signal) for the predetermined timer interval after the crank angle signal 22a is supplied, if a next crank angle signal 22a is supplied to the trigger input terminal 30E while the output signal 30f is supplied. The operation period of the mono-stable multivibrator 30B is set to approximately 0.5 seconds, for example. The mono-stable multivibrator 30B stops its operation when the logic level of the signal supplied to the enable input terminal 30D is at the H level, and outputs the H-level output signal 30f (timer output signal) via the output terminal 30F. The 3-input AND circuit 30A receives not only a starter switch operating signal which becomes the H level when the starter switch 8 is operated, but also the output signal 30f (timer output signal) from the mono-stable multivibrator 30B. An AND output signal 30a of the 3-input AND circuit 30A is supplied to the enable input terminal 30D of the mono-stable multivibrator 30B and the gate activating circuit 30C. Receiving the H-level AND output signal 30a from the 3-input AND circuit 30A, the gate activating circuit 30C supplies gate power to a gate of the field effect transistor 14 for activating the starting motor in order to make the transistor 14 conductive. When the field effect transistor 14 becomes conductive, the DC power is supplied to the. starting motor 13 from the battery 4, thereby rotating the starting motor 13. In the foregoing configuration, if both the starter and stop switches 8 and 9 are turned on when the output signal (timer output signal) 30f from the mono-stable multivibrator 30B has the H level, i.e., when the crankshaft is not rotating, the AND output 30a of the 3-input AND circuit 30A becomes the H level. In response to the H-level AND output 30a, the gate power is supplied to the field effect transistor 14, which then becomes conductive to activate the starting motor 13. The H-level AND output 30a is also supplied to the enable input terminal 30D of the mono-stable multivibrator 30B, so that the vibrator 30B stops functioning as the mono-stable multivibrator, and outputs the H-level output signal (timer output signal) 30f. Even when the starting motor 13 remains active, the AND output 30a of the 3-input AND circuit 30A remains at the H-level so long as the starter and stop switches 8 and 9 are being operated. Therefore, the starting motor 13 can remain active via the gate activating circuit 30C and the field effect transistor 14. When either the starter switch 8 or the stop switch 9 is turned off, the AND output 30a of the 3-input AND circuit 30A becomes the L-level, so that the field effect transistor 14 is controlled to the inactive state, and the starting motor 13 is stopped. After the AND output 30a becomes the L level, the enable input terminal 30D of the vibrator 30B becomes the L level, thereby keeping the mono-stable multivibrator 30B active. The output signal (timer output signal) 30f becomes the L level in response to the crank angle signal 22a from the waveform shaping circuit 22. The L-level output signal (timer output signal) 30f is maintained during the rotation of the crankshaft (i.e., during the operation of the engine), or until the lapse of the timer interval after the crankshaft stops rotating (i.e., the engine stops operating). Therefore, even if both the starter and stop switches 8 and 9 are operated while the output signal 30f remains at the H-level, the AND output of the 3-input AND circuit 30A does not become the H level, so that it is possible to prevent restart of the starting motor 13 during the rotation of the crankshaft, or till the lapse of the timer interval after the crankshaft stops rotating. Fig. 4 is a cross sectional view showing the structure of the starting motor, the starter pinion of the inertia-engaged type and the ring gear fixed to the crankshaft. When the starting motor 13 is activated, its rotating force is transmitted to the inertia actuated gear mechanism 115 via an input gear 116 to engage with a starting motor pinion gear 132 at a tip 131 of the starting motor 13. A starter pinion gear 117 is caused to project to the left by inertia force (in fig. 4) , engages with the ring gear 77a on an outer peripheral surface of a stationary pulley half 77 to rotate the pulley half 77 with the crankshaft .140, thereby starting the engine 150. In Fig. 4, reference numeral 111 denotes an outer stator magnet, and reference numeral 112 denotes an inner rotor coil. Reference numeral 78 denotes a rotatable pulley half. Reference numeral 127 denotes a kick shaft. When a kicking pedal (not shown) coupled to the kick shaft 127 via a kick arm (not shown) is foot-operated to rotate the kick shaft against a return spring 101, a helical gear 100 is rotated integrally with the kick shaft 127. Thereafter, a helical gear 103 engaged with the helical gear 100 rotates integrally with a sliding shaft 102, and slides to the right against a friction spring 105. A ratchet wheel 104 engages with a ratchet 79a of a boss 79, thereby forcibly rotating the crankshaft 140 to activate the engine 150. Fig. 5 is a timing chart of the start control unit shown in Fig. 1. Specifically, Fig. 5(a) shows operation timing of the starter switch 8, Fig. 5(b) shows operation timing of the stop switch 9, and Fig. 5(c) shows operation timing of the starting motor 13. Fig. 5(d) shows the operating state of the engine, Fig. 5(e) shows the crank angle detecting signal 12a, Fig. 5(f) shows the crank angle signal 22a, i.e., the output of the waveform shaping circuit, and Fig. 5(f) shows the output signal 32a of the timer 32. When both the starter and stop switches 8 and 9 are depressed during the non-rotation of the crankshaft (i.e., during the non-operation of the engine) as shown in Figs. 5(a) and 5(b), the starting motor 13 beings to operate at the time tl when the switches 8 and 9 are turned on, as shown in Fig. As soon as the starting motor 13 is rotated, the starter pinion gear 117 of the inertia-engaged type gear mechanism 115 is projected to engage with the ring gear 77a formed around the stationary pulley half 77, as shown in Fig. 4. Sinre the stationary pulley half 77 is fixed on the crankshaft 140, the crankshaft 140 is rotated by the rotating force of the starting motor 13 to activate the engine 150 as shown in Fig. 5(c). The rotation of the crankshaft 140 is detected by the pulser 12. Each time the crankshaft 140 rotates to a predetermined angle, the pulser 12 outputs the crank angle detecting signal 12a as shown in Fig. 5(e). The waveform shaping circuit 22 shapes the crank angle detecting signal 12a to output the crank angle signal 22a, shown in Fig. 5(f). When both the starter and* stop switches 8 and 9 remain turned on, the timer input preventing NPN transistor 33 is kept conductive by the AND output (having the H level) of the 2-input AND circuit 31, which prevents the crank angle signal 22a from being input to the timer 32. Therefore, the output of the timer 32 is at the L level. When the starter and stop switches 8 and 9 are turned off at the time t2, the AND output of the 2-input AND circuit 31 changes to the L level, and the timer input preventing NPN transistor 33 is made non-conductive. The crank angle signal 22a is then input to the timer 32, so that the timer output signal 32a changes to the L level. As a result, the start relay activating NPN transistor 34 is made non-conductive, the contact l0a of the start relay 10 is opened, and power supply to the starting motor 13 is interrupted. Therefore, the starting motor 13 is stopped. The timer 32 keeps the H-level timer output 32a for the predetermined timer interval after the crank angle signal 22a is input, so that the L-level timer output 32a is maintained during the operation of the engine. If the final crank angle signal 22a is input at the time t4 when the engine stops operating, the timer output 32a changes to the H level in the predetermined timer interval, i.e., at the time t5. Even when the starter and stop switches 8 and 9 are turned on while the timer output signal 32 is kept at the L level (i.e., during the period to prevent restart of the starting motor), e.g., at the time t3, after the engine start operation is temporarily suspended at the time t2, the start control unit 3 keeps the start relay 10 open while the timer output signal 32a remains at the L level. Therefore, the starting motor 13 is not activated. The start control unit 8 makes the restart preventing NPN transistor 33 conductive while the timer output signal 32a remains at the L level, thereby preventing the NPN transistor 33 from becoming conductive by the AND output of the 2-input AND circuit 31. Therefore, so long as the crank angle signals 22a are being supplied, the timer output 32a does not change to the H level. As described, it is possible to prevent the starting motor 13 from being restarted during the operation of the engine, or during the timer interval after the engine stops operating. If both the starter and stop switches 8 and 9 are kept turned on when the engine is in operation or during the timer interval (e.g., at the time t3) after the engine stops operating, the starting motor 13 will be restarted at the time t5 when the timer output 32a changes to the H level. In accordance with the invention, the start control unit 3 keeps the starting motor 13 from being activated while the engine is in operation, or during the timer interval (i.e., during the period for preventing restart of the starting motor Shown in Fig. 5) after the engine steps operating. Therefore, it is possible to prevent the inertia actuated starter pinion gear 117 from engaging with the ring gear 77a which is rotating with the crankshaft. As described above, it is possible to prevent noise which may be caused if the starter pinion gear 117 engages with the rotating ring gear 77a or to prevent the starter pinion gear 117 from being damaged if it engages with the rotating ring gear 77a. The start control unit 3 of the invention enables the starting motor 13 to keep operating while both the starter and stop switches 8 and 9 are maintained in the active state. Therefore, it is possible to reliably start the engine using the operating power of the starting motor 13 even when the engine is slow to start. [Effect of the Invention] In the starter protector according to the invention, when the starter switch is turned on with the timer output suspended, the starting motor is kept active so long as the starter switch remains active, so that the engine can be reliably started using the operating power of the starting motor even when the engine is slow to start. Even when the starter switch is turned on while the engine is in operation or in the predetermined time period after the engine stops operating, the starting motor is not activated in response to the timer output. Therefore, it is possible to prevent the starter pinion from engaging with the rotating ring gear and to protect the engine starting system. The start control unit controlling the operation of the starting motor and the ignition unit controlling engine ignition are formed as an integral unit, and the signals from the ignition pulser are used as the signals indicative of the * -•*—- crank angle of the crankshaft. Therefore, it is possible to mamake the starter protector compact and reduce the cose thereof. [Reference Numerals] 1 ... starting/ignition system, 2... CDI unit, 3, 30 ... start control unit, 8 ... starter (start) switch, 9 ... stop switch, 10 ... start relay, 12 ... pulser, 13 ... starting motor, 14 ... starting motor activating field effect transistor, 22 ... waveform shaping circuit, 30F ... re-triggerable mono-stable multivibrator constituting timer, 31 ... 2-input AND circuit, 32 ... timer, 33 ... timer input preventing NPN transistor, 34 ... start relay activating NPN transistor, 36 ... restart preventing NPN transistor, 41 ... timer interval setting capacitor, 42 ... quick charge NPN transistor, 43 ... discharge resistor for setting timer interval, 77a ... ring gear, 115 ... inertia-engaged type gear mechanism, 117 ... starter pinion of inertia actuated type, 140 ... crankshaft. CLAIM: 1. A starter protector comprising: a ring gear fixed to a crankshaft; a starter pinion which is engaged with said ring gear by inertia; a starting motor supplying power to move said starter pinion; and a start control unit controlling the operation of said starting motor; characterised in that said start control unit receives a signal produced in accordance with the rotation of the crankshaft and a starter switch signal, and has a timer keeping a timer output for a predetermined period of time in response to the signal produced by the rotation of the crankshaft; said starting motor is operated when said starter switch is turned on during the absence of the timer output; and said starting motor is kept inactive until the timer output is suspended when said starter switch is turned on during the presence of the timer output. 2. The starter protector as claimed in claim 1, wherein said start control unit is integral with an ignition unit, and uses a signal from an ignition pulser as the signal in accordance with the rotation of the crankshaft. 3. A starter protector substantially as hereinbefore described with reference to and illustrated in the accompanying drawings.

Documents:

778-del-1998-abstract.pdf

778-del-1998-claims.pdf

778-del-1998-correspondence-others.pdf

778-del-1998-correspondence-po.pdf

778-del-1998-description (complete).pdf

778-del-1998-drawings.pdf

778-del-1998-form-1.pdf

778-del-1998-form-13.pdf

778-del-1998-form-19.pdf

778-del-1998-form-2.pdf

778-del-1998-form-3.pdf

778-del-1998-form-4.pdf

778-del-1998-form-6.pdf

778-del-1998-gpa.pdf

778-del-1998-petition-137.pdf

778-del-1998-petition-138.pdf

abstract.jpg