JPS60243364A - Starter - Google Patents

Abstract

PURPOSE:To prevent the damage of a starter by a method wherein a starting motor is driven through a magnet switch operating by the throw-in of a starting switch and the conduction of the switch is intercepted when the temperature of exciting coil of the magnet switch has arrived at a predetermined value. CONSTITUTION:When the starting switch 200 is switched ON, a transistor 2 in a relay 300 is put ON, thereafter, the transistor 3 is put ON after a predetermined time delay and a movable contact 1b is closed by the exciting of a coil 1a. Then, the attracting coil 10 and the holding coil 11 of a magnet switch 400 are conducted to close the movable contact 9a and the starter motor 500 is started. In this case, a normally closed bimetal 15 is opened to stop the motor 500 if the starter is driven for a long period of time without obtaining the perfect ignition of an engine and the temperature of the motor 500 is risen abnormally. In case the motor 500 is driven in no-load condition and the holding coil 11 is overheated, the normally closing bimetal 14 is opened and the motor 500 is stopped in the same manner.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a starter for driving an internal combustion engine.

(Prior art) In the conventional technology, as shown in Japanese Patent Application Laid-open No. 58-197469, the control transistor that controls the switching transistor that controls the operation of the starting relay to turn off is turned on faster than the switching transistor when the starting switch is turned on. By using a capacitor to prevent the motor from becoming overloaded, and by sensing it with a temperature sensor and turning off the switching transistor when the temperature of the scooter motor reaches a predetermined temperature, the starter can be driven under overload conditions and operated for long periods of time. If this is done, there is a method that can prematurely prevent starter burnout and centrifugal damage due to over-rotation with low power consumption.

However, in the conventional system described above, after starting the internal combustion engine,
Even if the starter motor is operated without load due to a faulty turning off of the start switch, etc., the temperature rise of the starter motor is low and it takes a long time for the temperature sensor installed in the scooter motor to reach the predetermined temperature that activates. There was a risk of damage to the starter.

(Object of the Invention) An object of the present invention is to prevent damage to the starter motor when the starter motor is operated with no load.

(Structure of the Invention) A starting switch, a magnetic switch that is activated by turning on the starting switch and has an excitation coil, a starter motor that is connected to the magnetic switch and drives the internal combustion engine, and a temperature of the excitation coil of the magnetic switch. The starter is equipped with a temperature sensor that detects the temperature of the starter motor and cuts off power to the starter motor when the temperature reaches a predetermined temperature.

(Example) The present invention will be described below with reference to embodiments shown in the drawings.

As shown in FIG. 1, 100 is an on-vehicle battery.

Reference numeral 200 denotes a start switch that works in conjunction with the kill switch, and one end of which is connected to the battery 100. 1a is the coil of the relay 300, one end of which is connected to the start switch 200, and 1b
is a movable contact that is attracted by the coil 1a, and IC is a fixed contact, one of which is connected to the battery 100. Reference numeral 2 denotes a switching transistor that turns on and off the excitation current of the coil 1a. Reference numeral 3 denotes a control transistor for controlling the base current of the switching transistor 2, whose emitter is grounded and whose collector is connected to the heath of the switching transistor 2. Reference numeral 4 denotes a capacitor which delays the turning on of the control transistor 30 compared to the switching transistor 2, and is arranged between the gate and emitter of the control transistor 3. The resistors 5 and 6 are used to control the base current of the control transistor 3, and the resistor 7 is used to control the base current of the switching transistor 2. The diode 8 bypasses the surge current generated when the coil la is deenergized. The magnetic switch 400 has a movable contact 9a that is attracted to the attraction coil 10 and the holding coil 11 that constitute the excitation coil, and a fixed contact 9b that is connected to the battery 100 and the starter motor 500, respectively.The attraction coil 10 and the holding coil 11 are connected to one side. is connected to the fixed contact IC of the relay 300, and the other end of the holding coil 11 is grounded via the shunt coil 16 of the starter motor 500. In the starter motor 500, the field coil 12 and the armature 13 are directly connected, and the rotation of the armature 13 is transmitted to the internal combustion engine to start the internal combustion engine.

As shown in FIG.
A cushion 23 provided on a frame 22 for storing 1
By fixing the cover 24 to the frame 22 with screws 25, the cover 24 is placed and fixed on the outer periphery of the holding coil 11 wound around the outer periphery of the movable contact 9a, and on the outside of the wound attraction coil 10.

In addition, as shown in FIG. 3, a second normally closed bimetal 15
is fixed to the inner periphery of the end frame 21 of the armature 13 and is attached by screws 25 or the like to the side opposite to the brush 20 of the holder plate 17 that fixes the brush holder 19 that holds the brush 20 that is in contact with the commutator 18. ing.

One end of the first bimetal 14 is connected to the relay 3.
00, and its other end is connected in series to the other end of the 20th rich closed bimetal 15, one end of which is grounded.

Next, the operation of the above configuration will be explained. When the start switch 200 is closed, a base current flows into the switching transistor 2 via the resistor 7, and the switching transistor 2 is turned on. At the same time, the coil la, the resistor 6, and the capacitor 4 are energized to charge the capacitor 4, and the control transistor 3 is turned on later than the switching transistor 2.

Therefore, most of the current flows between the collector and emitter of the switching transistor 2, which was turned on first, and the coil 1a
The magnetic flux excited by the magnetic flux causes the movable contact 1b and the fixed contact 1c to
closes. When relay 300 is turned on in this manner, power is supplied from battery 100 to magnet switch 400, current flows through attraction coil 10 and holding coil 11, movable contact 9a and fixed contact 9b close, and starter motor 500 starts. In this state, the potential difference between the collector and emitter of the switching transistor 2 becomes non-currently small, and the Hose voltage of the control transistor 3 does not rise enough to turn on the control transistor 3, and the on state of the switching transistor 2 is maintained. Ru. Then, by starting the starter motor 500, the pinion of the armature 13 is rotated, and the internal combustion engine is driven via the ring gear. Further, when the starting switch 200 is opened, the coil 1a is quickly deenergized by the action of the diode 8, and the capacitor 4 is also discharged by the resistor 5, returning to its initial state.

Now, if the starter is driven for a long time when the engine is difficult to start, or if the starter is driven at a low temperature and in an overloaded state where the engine starting resistance is large, the temperature of the starter motor 500 will rise rapidly, and this heat will cause the holder plate 17 to The second normally closed bimetal 15 installed at a predetermined temperature (approximately 15
It opens when it reaches 0.

In addition, 1. After the internal combustion engine starts, even if the armature 13 of the scooter motor 500 is rotated by the internal combustion engine due to an opening failure of the starting switch 200, etc., and the motor is operated under no load, the temperature rise of the starter motor 500 is low, and the starter motor 500 has a low temperature rise. It takes a long time to reach the predetermined salinity (approximately 150° C.) at which the second normally closed bimetal 15 provided in the motor 500 operates. However, the holding coil 11 is overheated, and this heat heats the first normally closed bimetal 14 via the suction coil 10, which opens when a predetermined temperature (approximately 100° C.) is reached. After about 5 minutes of continuous no-load operation of the starter motor 500, the first regular bimetal 14 reaches a predetermined temperature (about 1
00℃). Therefore, even if the starter motor 500 is operated under no load, the first regular use terminal 14 can be opened in a short time (approximately 5 minutes), thereby reducing damage to the starter motor 500.

Furthermore, if the movable contact 9a and the fixed contact 9b of the magnet switch 400 cause a conduction failure, and the suction coil 10 is energized for about 30 seconds via the battery 100 and the fixed contact 1c and the movable contact 1b of the relay 300, the suction coil l
Due to the rapid heat generation of O, the first normally closed bimetal 14 reaches a predetermined temperature (approximately 100°C), and the first normally closed bimetal 14
to open. Therefore, it is possible to prevent current from flowing through the attraction coil 10 for a long time and damaging the attraction coil 10 and the like.

In the above, when the first normally closed bimetal 14 or the second normally closed bimetal 15 opens while the starting switch 200 is closed, the base current of the switching transistor 2 is cut off and turned off, so that the coil 1a is deenergized. , the starter motor 500 stops and the power to the magnet 400 is cut off. Then, the capacitor 4 is charged via the resistor 6, the base voltage of the control transistor 3 increases, and the control transistor 3 is turned on.

Next, after the starter motor 500 has stopped, the stark motor 50
The temperature of the 0 section or the temperature of the 10 section of the suction coil drops to a safe range, and the first normally closed bimetal 14 or the second normally closed bimetal 14
When the bimetal 15 returns and closes, voltage is supplied to the base and collector of the switching transistor 2, but since the control transistor 3 is in the on state, the base of the switching transistor 2 is not supplied with power, and the coil Since a current sufficient to attract movable contact 1b does not flow through 1a, starter motor 500 maintains a stopped state.

For restarting, the initial state can be returned by forcibly turning off the Nutak starting circuit path such as the starting switch 200.

Note that the switching transistor 2 may be of a Darling-connected type, and the first normally closed bimetal 14 and the second normally closed bimetal 15 may be positive temperature characteristic thermistors.

In addition, if the installation part of the first sealed bimetal 14 can sense the heat generated by the suction coil 1, the magnetic switch 40
It can be anywhere between 0.

Furthermore, it goes without saying that the second normally closed bimetal 15 may be installed not only on the holder plate 17 but also anywhere on the starter motor 500 as long as it can sense the heat generated by the starter motor 500.

Even without using the second normally closed bimetal 15, it is possible to prevent damage to the starter due to no-load operation of the scooter motor 500 and poor conduction between the fixed contact 9b and the movable contact 9a of the magnetic switch 400.

Further, in the above embodiment, the first normally closed bimetal 14 was used as a temperature sensor for detecting the temperature of the excitation coil of the McNet switch 400 connected to the relay 300. Instead, if a temperature fuse 17 is connected between the starting switch 200 and the connection point between the attraction coil 10 and the holding coil 11 as shown in FIG. 4, the above embodiment can be achieved without using the relay 300. A similar effect can be obtained.

In addition, Relay 300 Suinoching Toranonsk 2,
Although the control transnoster 3 and the capacitor 4 form the self-holding circuit of the temperature sensor, the self-holding circuit of the temperature sensor may also be formed using a cyrisk or the like.

(Effects of the Invention) As described above, the present invention is equipped with a temperature sensor that detects the temperature of the excitation coil of the magnetic switch and cuts off power to the starter motor when this temperature reaches a predetermined temperature. If the scooter motor is operated under no load due to a malfunction of the switch and heat is generated in the excitation coil of the magnetic switch, the power to the starter motor is cut off, preventing FN (IA) of the starter motor, etc. When a conduction failure occurs and heat is generated in the excitation coil of the magnetic switch, the power supply to the magnetic switch is cut off, which has the excellent effect of preventing damage to the magnetic switch.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram showing an embodiment of the starter of the present invention;
FIG. 2 is a partially sectional front view showing the installation of the first normally closed bimetal of the above embodiment; FIG. 3 is a partially sectional front view showing the installation of the second closed bimetal of the practical example; FIG. 4 is an electric circuit diagram showing another embodiment of the starter of the present invention. 100...Battery, 200...Start switch, 4
00... Magnet switch, 500... Scooter motor, 10.11... Attraction coil and holding coil each forming an excitation coil, 14.17... First normally closed bimetal forming each temperature sensor, temperature Hughes.

Claims (1)

[Claims] A starting switch, a magnetic switch that is activated by turning on the starting switch and has an excitation coil, a starter motor that is connected to the magnetic switch and drives an internal combustion engine, and an excitation coil of the magnetic switch. A starter comprising: a temperature sensor that detects temperature and cuts off power to the starter motor when the temperature reaches a predetermined temperature. of