JPS637262B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a starter starting device for a starter having a magnetic switch.

Conventionally, as shown in FIG. 1, a starter device known from, for example, Japanese Unexamined Patent Publication No. 55-148959, supplies power to the attraction coil 4 and holding coil 5 of the magnetic switch 3 when the key switch 1 is closed, and the movable iron core 1
2, the movable contact 9 becomes fixed contact 8 _a , 8 _b
was closed and power was supplied to the motor circuit 11 to operate it.

By the way, the suction coil 4 is operated for 10 to 15 ms until the contacts 8 _a , 8 _b , and 9 are closed, so a thick wire is wound around it and a current of several 10 A is applied (when the contacts close, the suction coil 4
Since the holding coil 5 is energized until the engine is started and the key switch 1 is opened, the holding coil 5 is wound with a thin wire so that the temperature rise can be kept low.

However, in the above configuration, when the movable contact 9 and fixed contacts 8 _a and 8 _b are closed and the attraction coil 4 is short-circuited, the magnetomotive force of the holding coil 5 overcomes the pushing force of the spring 13 and further bends the contact spring 10. There is a drawback that if the movable contact 9 is not pressed, the movable contact 9 will flap. In addition, when the wiring resistance 2 is large, the voltage at the M terminal becomes higher than the voltage at the S terminal, causing a backflow in the attraction coil 4, reducing the magnetomotive force of the holding coil 5, and causing the contact 9 to fluctuate as described above. It has the disadvantage of shortening its lifespan.

The present invention provides a starter starting device that prevents the movable contact from fluttering during starting and suppresses a decrease in contact life in a starter that controls the movable contact using a suction coil and a holding coil. There is a particular thing.

For this purpose, the present invention opens and closes the energizing circuit of the attraction coil depending on the energization state of the motor circuit, so that the holding force of the holding coil is not reduced by the backflow of the attraction coil. Alternatively, the energization of the attraction coil is stopped at the timing when the movable contact stops at a predetermined position.

Hereinafter, the present invention will be explained according to illustrated embodiments.

FIG. 2 is a circuit diagram showing an embodiment of the first aspect of the present invention.

In FIG. 2, 7 is a battery, 1 is a key switch, 3 is a magnetic switch, 5 is a holding coil, and 4 is an attraction coil, and the attraction coil 4 is grounded through a Darlington connection transistor 14. 15 is a Zener diode that operates the transistor 14; 16 is a resistor for determining the base current of the transistor 14; and 17 is a diode that is activated depending on the energization state of the motor circuit 11. In addition, 12 is a movable iron core, which includes a movable contact 9 and a contact spring 1 that provides contact pressure to the movable contact 9.
0 and a spring 13 for pushing back the movable core 12, and the suction coil 4 and the holding coil 5 are arranged concentrically with respect to the movable core 12.

In the above configuration, when the key switch 1 is closed, battery voltage is supplied from the battery 7 to the attraction coil 4 and holding coil 5 of the magnetic switch 3. The movable core 12 moves by overcoming the force of the return spring 13 due to the magnetomotive force in the axial direction of both coils, and the contact closes. Here, when the voltage at the S terminal is higher than the Zener voltage of the Zener diode 15, a base current flows to the transistor 14 through the resistor 16, and the transistor 14 is activated. Thus, by closing the fixed contacts 8 _a and 8 _b , a large current is supplied from the battery 7 to the motor 11 and the motor 11 is fully operated. When the movable contact 9 and the fixed contacts 8 _a and 8 _b are closed, the M terminal voltage V _M becomes lower than the battery voltage V _B (voltage drop between the battery M terminals), and the voltage applied to the Zener diode 15 becomes lower than the Zener voltage. As a result, the operation of the transistor 14 is stopped and the power supply to the attraction coil 4 is stopped, but the movable core 12 is held in position by the holding coil 5.

By opening the key switch 1, the magnetomotive force of the holding coil 5 disappears, and the movable iron core 1
2 also returns to its original position, contacts 8 _a , 8 _b , and 9 are also opened, and the motor 11 stops.

As described above, in this embodiment, the suction coil 4
A transistor 14 is provided in the power supply circuit, and this power supply circuit is opened and closed by a Zener diode 15. Since the Zener diode 15 is operated depending on the voltage of the S terminal or the power supply state of the motor circuit 11, It is possible to prevent the contact 9 from flapping. At the same time, since the magnetic switch 3 does not operate when the battery voltage is below a specified value, there is an advantage that forced operation of the motor can be prevented and failure can be prevented.

FIG. 3 is a circuit diagram showing another embodiment according to the first invention, in which a transistor 20 is used in place of the diode 17. That is, when the key switch 1 is closed, a voltage is applied to the Zener diode 15, a base current flows to the transistor 14 through the resistor 16, and the attraction coil 4 is activated. Next, when the contacts 8 _a , 8 _b , and 9 close, the voltage at the M terminal opens the transistor 20 through the resistor 21 , the Zener voltage decreases, the transistor 14 stops operating, and the power supply to the attraction coil 4 is stopped. . Therefore, the same effect as in the case of FIG. 2 is obtained.

FIG. 4 is a circuit diagram showing an embodiment of the second aspect of the present invention. In FIG. 4, 17 is a diode that is activated depending on the energization state of the motor circuit 11, 21 is a resistor for voltage division, and 23 is a capacitor that controls the rising time of the voltage applied to the terminal of the Zener diode 15, which is connected in parallel with the resistor 22. to determine the rise time. Note that the same parts as in FIG. 2 are represented by the same symbols.

In the above configuration, when the key switch 1 is closed, battery voltage is supplied from the battery 7 to the attraction coil 4 and holding coil 5 of the magnetic switch 3. The movable core 12 moves by overcoming the force of the return spring 13 due to the magnetomotive force in the axial direction of both coils, and the contacts 8 _a , 8 _b , and 9 close. Here, when the voltage at the S terminal is higher than the Zener voltage of the Zener diode 15, a base current flows through the resistor 16 and the transistor 14 is activated. Thus, by closing the fixed contacts 8a _{and 8b} , the battery 7
A large current is supplied from the motor 11 to the motor 11, and the motor is fully operated. Note that when the movable contact 9 and fixed contacts 8 _a and 8 _b are closed, the M terminal voltage V _M becomes lower than the battery voltage V _B (voltage drop between the battery M terminals), and the voltage applied to the Zener diode 15 becomes less than the Zener voltage. The operation of the transistor 14 is stopped, and the power supply to the attraction coil 4 is stopped.

Here, the capacitor 23 controls the rise time of the voltage applied to the diode 17 through a parallel circuit with the resistor 22, and after contacting the movable contact 9, the movable iron core 12 deflects the contact spring 10 (not shown). The voltage applied to the diode 17 is controlled so that the power supply to the attraction coil does not stop until it reaches the fixed iron core. By the way, the time from when the contact closes until the movable core and fixed core come into contact is several milliseconds, and the capacitor is used to extend the power supply time by approximately 10 milliseconds. In this way, the movable core 12 that is in close contact with the fixed core is no longer supplied with electricity by the attraction coil 4, and its position is maintained by the magnetomotive force of the holding coil 5. By opening the key switch 1 after starting the engine, the magnetomotive force of the holding coil 5 disappears, and the movable iron core 1
2 also returns to its original position, contacts 8 _a , 8 _b , and 9 are also opened, and the motor 11 stops.

As described in detail above, in this embodiment, the transistor 14 is provided in the power supply circuit of the attraction coil 4, and the power supply circuit is opened and closed by the Zener diode 15. Moreover, the movable contact is closed by the action of the capacitor 23, and moreover, after the fixed iron core and the movable iron core are brought into close contact, the diode 17 operates to close the circuit of the transistor 14. In a conventional circuit with a large wiring resistance 2, a backflow phenomenon occurred in the attraction coil 4 due to the voltage difference between the S terminal and the M terminal, its holding force was reduced, and the contact 9 fluttered, but this phenomenon has never occurred. becomes. Furthermore, if the battery voltage is below the specified value, the Zener diode 15 will not operate and the magnetic switch 3 will not operate, so there is an advantage that forced operation of the motor can be prevented and breakdowns can also be prevented.

FIG. 5 is a circuit diagram showing another embodiment of the second invention, in which a transistor 2 is used instead of the diode 17.
This is an example using 4. Even with this configuration, the same effects as in FIG. 4 can be obtained.

As is clear from the above description, according to the present invention, in a starter that controls a movable contact using a suction coil and a holding coil, it is possible to prevent the movable contact from fluttering during startup and to suppress a decrease in contact life. It is possible to improve reliability and maintainability.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a conventional starter starting device, FIGS. 2 and 3 are circuit diagrams showing an embodiment of the first invention, and FIGS. 4 and 5 are circuit diagrams showing an embodiment of the second invention. FIG. 1... Key switch, 3... Magnetic switch, 4... Attraction coil, 5... Holding coil, 9...
...Movable contact, 14...Transistor, 15...Zener diode, 17...Capacitor.

Claims (1)

[Claims] 1. In a starter having a magnetic switch in which a movable iron core is controlled by two coils, an attraction coil and a holding coil, the magnetic switch terminal voltage to which the attraction coil is connected and the contact terminal of the starter switch A starter starting device characterized in that a semiconductor switch element is provided which compares the voltage and supplies power to the attraction coil only while the magnet switch terminal voltage is high or when the battery voltage is higher than the specified voltage. 2. In a starter with a magnetic switch in which the movable core is controlled by two coils, an attraction coil and a holding coil, the attraction coil is energized at the timing when the contacts of the motor circuit close and the movable core stops at a predetermined position. A starter starting device characterized by being provided with a semiconductor switch element for stopping.