JPH0521171U - Starter drive controller for internal combustion engine - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] When a condition occurs in which the engine is operating at a speed lower than the normal idling speed immediately after the engine is started,
Eliminate the risk that the starter motor will be damaged due to continued power supply to the starter motor due to a malfunction of the key switch. A timer circuit 9 for starting a timed operation when a start-up energizing contact 1c of a key switch 1 is connected to a battery 2 is provided. When the timer circuit 9 finishes the timed operation, the thyristor S3 is made conductive, and a current is passed from the battery 2 through the thyristor S3 to the exciting coil 3a of the electromagnetic relay 3. As a result, the contact 3b of the electromagnetic relay 3 is opened to stop energizing the starter motor 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a starter drive control device for controlling energization of a starter motor of an internal combustion engine.

[0002]

[Prior Art]

 In an electric start type internal combustion engine, it is necessary to energize the starter motor when the key switch is switched to the starting position and stop energization to the starter motor after the engine is started. Conventionally, when the driver confirms that the engine has started, the power supply to the starter motor is stopped by returning the key switch from the starting position to the operating position, but the starter switch is returned to the operating position due to an erroneous operation. If the operation is delayed, the starter motor will be driven by the engine in reverse and become over-rotated, possibly resulting in damage.

Therefore, a starter drive control device has been proposed in which the power supply to the starter motor is automatically stopped when it is confirmed that the engine has started. FIG. 3 shows a conventional starter drive control device of this type. In FIG. 3, reference numeral 1 is a well-known key switch. The key switch includes at least a movable contact 1a connected to a non-grounded terminal of the battery 2 (a positive electrode terminal in this example), a running energizing contact 1b, and a starting energizing contact 1c. When the engine is started, the movable contact 1a is operated by a key (not shown) to first switch to the operating position where it contacts the running energization contact 1b, and then the starting energization is maintained while maintaining contact with the running energization contact 1b. It is switched to the starting position where it comes into contact with the working contact 1c. When the movable contact 1a is at the starting position and the key is released, the movable contact automatically returns to the operating position by the urging force of the return spring. Therefore, the contact 1b for energization during operation is connected to the battery through the movable contact 1a during starting and operation of the engine, and the contact 1c for energization during startup is connected to the battery through the movable contact only when the engine is started.

In the starter drive control device of FIG. 3, when the movable contact of the key switch 1 is switched to the starting position through the operating position (the movable contact 1a is brought into contact with the contacts 1b and 1c), the battery 2 → key switch 1 → electromagnetic A normally-closed contact 3b of the relay 3 → the starter energizing circuit of the starter motor 4 is configured to energize the starter motor 4. As a result, the starter motor 4 is driven, and the pinion gear attached to the output shaft of the starter motor pops out and meshes with the drive gear attached to the crankshaft of the engine. The crankshaft of the engine is rotated by the rotation of the starter motor, and the engine is started.

When the engine is rotated by the starter motor, the magnet generator 5 attached to the engine starts power generation, and its output is applied to the battery 2 through the battery charge control circuit 6. When the voltage of the battery 2 is less than or equal to the set value, the Zener diode Z 1 does not conduct, so the transistor Tr 1 is in the cutoff state. At this time, since a base current flows from the battery 2 to the transistor Tr2 through the emitter base of the transistor Tr2, the resistor R1 and the diode D7, the transistor Tr2 becomes conductive. Therefore, the trigger signal is applied from the battery 2 to the thyristors S1 and S2 through the transistor Tr2, the resistor R2 and the diodes D3 and D4. As a result, the thyristors S 1 and S 2 are turned on, and the output of the generator 5 is such that the charging current flows through the path of the generator 5 → diode D 1 or D 2 → battery 2 → thyristor S 1 or S 2 → generator 5 Be charged.

The output voltage of the generator 5 increases as the engine speed increases. When the engine start is completed and the engine speed reaches the set value Ns and the output voltage of the generator 5 reaches the set value, the Zener diode Z2 becomes conductive, so the generator 5 → diode D1 or D2 → key A current flows through the path of switch 1 → PUT (programmable unijunction transistor) P1 anode gate → zener diode Z2 → resistor R4 → diode D5 or D6 → generator 5 and PUTP1 conducts. Accordingly, the battery 2 → PUTP1 → excitation coil 3a of the electromagnetic relay 3 → current flows through the path of the battery 2 to excite the excitation coil of the electromagnetic relay 3, so that the contact 3b of the relay is opened and the starter motor 4 is opened. Energization is stopped. Once the PUT is conductive, it maintains the conductive state until the application of the power supply voltage is stopped (until the key switch is opened), so that the contact 3b of the electromagnetic relay 3 is maintained in the open state during engine operation. In this example, the resistor R4, the Zener diode Z2 and the PUTP1 constitute a starter protection circuit 7 which energizes the exciting coil 3a of the electromagnetic relay 3 when the engine speed reaches a set value.

In FIG. 3, reference numeral 8 is a charge display circuit, and this circuit operates as follows. When the key switch 1 is switched to the operating position (the movable contact 1a is brought into contact with the contact 1b), the base current flows through the transistor Tr3 along the path of the battery 2 → the emitter base of the transistor Tr3 → the resistor R6 → the diode D9 → the battery 2 Tr3 becomes conductive. At this time, a current flows through the path of battery 2 → transistor Tr3 → diode D8 → display lamp L1 → battery 2, so that the display lamp L1 is turned on to indicate that the battery is not charged. When the engine starts and the generator 5 starts to generate electricity, the transistor Tr4 is in the path of generator 5 → diode D1 or D2 → key switch 1 → transistor T4 emitter base → resistor R5 → diode D6 or D7 → generator 5. The base current flows to. As a result, the transistor Tr4 becomes conductive, the transistor Tr3 is turned off, and the indicator lamp L1 is turned off to indicate that the battery can be charged.

[0008]

[Problems to be solved by the device]

 In the above starter drive control device, as shown in FIG. 4, when the key switch 1 is switched to the starting position at time to, the engine speed increases as shown by the solid line in the figure. .. When the engine speed exceeds the set rotational speed N s of the starter protection circuit 7, the power supply to the starter motor 4 is stopped. Since the set speed Ns is set slightly lower than the idling speed of the engine, the starter motor is not energized when the engine is idling.

However, as indicated by the broken line in FIG. 4, when the engine continues to operate at a rotational speed lower than the normal idling rotational speed for some reason after the engine has started, the starter protection circuit 7 The operation may be continued at a rotational speed lower than the set value Ns of. In this case, if the key switch does not return from the starting position to the operating position due to a malfunction of the key switch or a malfunction of the key switch, the starter motor may be rotated by the engine for a long time and the starter motor may be damaged. It was

The object of the present invention is to energize the starter motor due to an erroneous operation or failure of the key switch when a condition occurs in which the engine is operated at a speed lower than the normal idling speed immediately after the engine is started. It is an object of the present invention to provide a starter drive control device for an internal combustion engine, which eliminates the risk of continuing damage to the starter motor.

[0011]

[Means for Solving the Problems]

 The present invention relates to a battery charged by the output of a generator driven by an internal combustion engine, a contact for energization during operation connected to the battery at the time of starting and operating the engine, and a start connected to the battery only at the time of starting the engine. An internal combustion engine through a key switch with a contact for energizing the time, an electromagnetic relay with a normally closed contact that opens when the excitation coil is energized, and a contact for energizing the start of the key switch from a battery and a normally closed contact of the electromagnetic relay. A starter drive control device for an internal combustion engine equipped with a starter energizing circuit for energizing a starter motor for a vehicle and a starter protection circuit for energizing an exciting coil of an electromagnetic relay when the engine speed reaches a set value. is there.

In the present invention, in order to achieve the above object, a timer circuit that starts a timed operation when a start-time energizing contact of a key switch is connected to a battery, and the timer circuit ends the timed operation. A protective switch with a self-holding function, which is turned on at times and causes an exciting current to flow to the exciting coil of the electromagnetic relay, is further provided.

[0013]

[Action]

 If the timer circuit and protection switch are installed as described above, the electromagnetic relay contacts will always be opened regardless of the state of the key switch when a certain time has elapsed after the engine was started. Since the power supply to the starter motor is stopped, there is no risk of damage to the starter motor and reliability can be improved.

[0014]

【Example】

 FIG. 1 shows an embodiment of the present invention in which the timer circuit 9 and a thyristor S3 as a protection switch are added to the device of FIG. The timer circuit 9 includes an integrating circuit 9a including a capacitor C1 and a resistor R8, a reset circuit 9b including a transistor Tr5, diodes D11 and D12, resistors R14 and R15, and a flip-flop including transistors Tr6 and Tr7 and resistors R9 to R12. Circuit 9c, a flip-flop trigger circuit 9d consisting of a transistor Tr8 and a resistor R13, a zener diode Z3 and a diode D10. The voltage across the integrating capacitor C1 is the zener voltage of the zener diode Z3. When it exceeds, the trigger signal is given to the thyristor S3. The thyristor S3 is connected between the energizing contact 1b during operation of the key switch 1 and one end of the exciting coil of the electromagnetic relay 3 on the non-grounded side, and becomes conductive when the trigger signal is given to the exciting coil 3a. Supply current. Other configurations are the same as those of the conventional device shown in FIG. In the embodiment of FIG. 1, when the key switch 1 is switched to the operating position (the movable contact point 1a is brought into contact with the contact point 1b), the battery switch 2 and the normally closed contact point 3b of the electromagnetic relay 3 and the starter motor 4 are connected. An electric current flows through the starter motor 4 to drive the starter motor 4, and the pinion gear attached to the starter motor pops out and meshes with the drive gear attached to the crankshaft of the engine. As a result, the crankshaft of the engine is rotated and the engine is started.

When the engine is rotated by the starter motor 4, the magnet generator 5 attached to the engine starts power generation, and its output is applied to the battery 2 through the battery charge control circuit 6. When the voltage of the battery 2 is below the set value and the Zener diode Z1 does not conduct, the transistor Tr1 is in the cut-off state and the transistor Tr2 conducts, and the battery 2 passes through the transistor Tr2, the resistor R2 and the diodes D3 and D4. Since the trigger signal is applied to S1 and S2, the thyristors S1 and S2 are conducted, and the output of the generator 5 is supplied to the battery 2 through the control rectification circuit including the diodes D1 and D2 and the thyristors S1 and S2. When the voltage of the battery 2 exceeds the set value, the Zener diode Z1 becomes conductive, so that the transistor Tr1 becomes conductive and the transistor Tr2 becomes cut off. Therefore, the trigger signal is not given to the thyristors S1 and S2, and both thyristors cannot conduct, so that the power supply from the generator 5 to the battery 2 is stopped.

When the engine start is completed and the engine speed reaches the set value Ns and the output voltage of the generator 5 reaches the set value, the Zener diode Z2 conducts, so that the generator D1 or diode D1 or A current flows through D2, the key switch 1, the anode gate of the PUT (programmable unijunction transistor) P1, the Zener diode Z2, the resistor R4 and the diode D5 or D6, and the PUTP1 becomes conductive. Therefore, a current flows from the battery 2 through the PUTP1 and the exciting coil 3a of the electromagnetic relay 3 to excite the exciting coil of the electromagnetic relay 3. As a result, the contact 3b of the relay is opened, and the power supply to the starter motor 4 is stopped. When the power supply to the starter motor is stopped, the pinion gear attached to the starter motor automatically retracts from the gear attached to the crankshaft of the engine, so the starter motor is disconnected from the crankshaft of the engine. .. Once the PUT is conductive, it maintains the conductive state until the key switch is opened, and holds the contact 3b of the electromagnetic relay 3 in the open state during engine operation.

In the charge display circuit 8, when the key switch 1 is switched to the operating position, a current flows from the battery 2 through the emitter base of the transistor Tr3, the resistor R6 and the diode D9, and the transistor Tr3 becomes conductive. As a result, the display lamp L1 lights up to indicate that the battery is not being charged. When the engine is started and the generator 5 starts generating electricity, a base current flows from the generator 5 to the transistor Tr4 through the diode D1 or D2, the key switch 1, the emitter base of the transistor T4, the resistor R5 and the diode D6 or D7. Since the transistor Tr4 is turned on, the transistor Tr3 is turned off and the display lamp L1 is turned off.

The timer circuit 9 operates as follows. The flip-flop circuit 9c is configured such that when the transistor Tr8 is off, the transistor Tr6 is conductive and the transistor Tr7 is off. Therefore, when the key switch 1 is switched to the operating position, the transistor Tr7 is in the cutoff state, and the base current flows from the battery 2 to the transistor Tr5 through the key switch 1, the resistors R10 and R14 and the diode D11. As a result, the transistor Tr5 becomes conductive, so that the integrating capacitor C1 is not charged. When the key switch 1 is switched to the starting position at time t0, the trigger signal Vb is applied from the battery 2 to the base of the transistor Tr8 through the key switch 1 and the resistor R13 as shown in FIG. 2 (A). , The transistor Tr8 is turned on, and the transistor Tr6 of the flip-flop circuit 9c is turned off. Therefore, the transistor Tr7 becomes conductive, and the transistor Tr7 bypasses the base current of the transistor Tr5 from the transistor Tr7. This turns off the transistor Tr5, so that a voltage is applied from the battery 2 to the integrating capacitor C1 through the key switch 1 and the resistor R8.

Therefore, as shown in FIG. 2B, at the time to, the key switch 1 is switched to the starting position, and at the same time, the charging (timed operation) of the integrating capacitor C1 is started, and the voltage across the integrating capacitor C1 is started. Vc rises.

After a certain period of time elapses after the key switch 1 is switched to the starting position, the voltage Vc across the product capacitor C1 exceeds the zener voltage V z of the zener diode Z3, so the zener diode Z3 becomes conductive. And give a trigger signal to thyristor S3. As a result, the thyristor S3 becomes conductive, and the exciting voltage Vy is applied from the battery 2 to the exciting coil 3a of the electromagnetic relay through the key switch 1 and the thyristor S3 as shown in FIG. 2 (C). As a result, the exciting coil 3a of the electromagnetic relay is excited, the contact 3b is opened, and the power supply to the starter motor 4 is stopped.

Therefore, as shown by a broken line in FIG. 4, after starting the engine, the idling operation is performed at a rotation speed lower than the set rotation speed Ns of the starter protection circuit 7 for some reason, and the starter protection circuit is started. If 7 does not work, the thyristor S3 of the timer circuit 9 becomes conductive at the time t1 when a predetermined time Ts has elapsed after the key switch was switched to the starting position at the time to, and the exciting coil of the electromagnetic relay 3 was turned on. 3a is excited to stop energizing the starter motor. Further, when the thyristor S3 is turned on, a base current is applied to the transistor Tr5 through the resistor R15 and the diode D12, and the transistor Tr5 is turned on to discharge the integrating capacitor C1.

In the above embodiment, the thyristor S3 is made conductive when the voltage across the integrating capacitor C1 exceeds the Zener voltage of the Zener diode Z3. However, the voltage across the integrating capacitor C1 and the reference voltage And a comparator circuit for comparing the output of the comparator circuit is supplied to the gate of the thyristor S3, and when the voltage across the integrating capacitor C1 exceeds the reference voltage, the output of the comparator circuit is set to a high level. It is also possible to trigger S3.

In the above embodiment, the trigger signal is applied from the battery 2 to the transistor Tr8 through the key switch when the key switch 1 is switched to the starting position, but the transistor Tr8 is triggered by the output of the generator 5. You may give a signal.

In the above embodiment, when the resistor R15 and the diode D12 are not provided, when the key switch is opened, the capacitor C1 → the resistor R8 → the thyristor S3 → the exciting coil 3a of the electromagnetic relay → the capacitor C1. The integration capacitor C1 is discharged along the path, but if the engine is stopped and restarted in a short time, the integration capacitor C1 may not be discharged in time, and there is a charge remaining on the integration capacitor C1 when the engine is started. If this happens, the timer setting time may be incorrect. If the diode D12 and the resistor R15 are provided as in the above embodiment so that the transistor T r5 is turned on at the same time as the thyristor S3 is turned on, the capacitor C1 is discharged.

[0025]

[Effect of the device]

 As described above, according to the present invention, the timer circuit that starts the timed operation when the start-up energizing contact of the key switch is connected to the battery and the timer circuit that conducts when the timer circuit finishes the timed operation. Since a protective switch with a self-holding function that allows a current to flow through the exciting coil of the electromagnetic relay is provided, it is possible to check whether the key switch is in a certain state for a certain period of time after starting the engine. Therefore, there is an advantage that the power supply to the starter motor can be stopped without fail, and the reliability of the starter motor can be improved without damaging the starter motor.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

2A to 2C are waveform diagrams for explaining the operation of the timer circuit used in the embodiment of FIG.

FIG. 3 is a circuit diagram of a conventional device.

FIG. 4 is a diagram showing a temporal change in the number of revolutions at the time of starting the engine.

[Explanation of symbols]

1 ... Key switch, 2 ... Battery, 3 ... Electromagnetic relay, 4
... Starter motor, 5 ... Generator, 6 ... Battery charge control circuit, 7 ... Starter protection circuit, 8 ... Charge display circuit, 9 ...
Timer circuit, 9a ... Integrating circuit, 9b ... Reset circuit, 9
c ... Flip-flop circuit, 9d ... Trigger circuit of flip-flop circuit, S3 ... Thyristor (protection switch).

Claims (1)

[Scope of utility model registration request] 1. A battery charged by the output of a generator driven by an internal combustion engine, a contact for energization during operation connected to the battery at the time of starting and operating the engine, and a battery connected only at the time of starting the engine. A key switch having a start-up energizing contact, an electromagnetic relay having a normally-closed contact that opens when the excitation coil is energized, and a start-up energizing contact of the key switch from the battery and a normally-closed contact of the electromagnetic relay. A starter drive control device for an internal combustion engine, comprising: a starter energizing circuit for energizing a starter motor for an internal combustion engine; and a starter protection circuit for energizing an exciting coil of the electromagnetic relay when the engine speed reaches a set value. A timer circuit that starts a timed operation when the start-up energizing contact of the key switch is connected to a battery; The conduct current when finishing the work electromagnetic relay starter for an internal combustion engine drive control apparatus characterized by comprising a protection switch with self-holding function of supplying an exciting current to the exciting coil.