JPH0644398U - Wiper control device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a wiper control device having high reliability by preventing an arc from being generated between contacts of a relay. A wiper control device 1 comprising a prohibition circuit 6 for holding a timer time T1 relay RL1 which is assumed to generate a lock current of a wiper motor 2 in a stationary state.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a wiper control device used for intermittently operating a wiper in a wiper for wiping a wiping surface such as a windshield glass.

[0002]

[Prior art]

 As a wiper control device for intermittently operating the wiper, one shown in FIG. 6 is known.

In the illustrated wiper control device 50, when the intermittent wiper switch 51 is turned on, the relay drive circuit 52 operates to turn on the relay coil 53 a of the intermittent relay 53 for a preset time. Since 53b is switched from the normally closed fixed contact 53c to the normally open fixed contact 53d, the current of the wiper motor 55 flows from the movable contact 53b of the intermittent relay 53 to the normally open fixed contact 53d of the intermittent relay 53 to the earth, and the wiper motor 55 becomes The wiper surface rotates and wipes the wiping surface with a wiper blade (not shown) connected to the motor shaft 55a of the wiper motor 55.

After an arbitrary time from the start of rotation of the wiper motor 55, the relay drive circuit 52 is turned off, the relay coil 53a of the intermittent relay 53 is turned off, and the movable contact 53b of the relay 53 is changed to the normally closed fixed contact 53c. Although it is switched, the movable contact 56a is brought into contact with the earth side fixed contact 56b until the wiper blade returns to a predetermined stop position by the stop position detection switch 56 connected to the motor shaft 55a of the wiper motor 55, and the wiper blade is stopped for a predetermined time. When the movable contact 56a returns to the position, the movable contact 56a comes into contact with the fixed contact 56c on the power supply side. Therefore, when the movable contact 56a of the stop position detection switch 56 is on the fixed contact 56b on the ground side, the movable contact of the intermittent relay 53 moves. 53b-> The normally open fixed contact 53d of the intermittent relay 53-> flows to the ground, and the stop position detection switch When the movable contact 56a of 56 comes to the fixed contact 56c on the power supply side, the movable contact 53b of the intermittent relay 53 → the normally closed fixed contact 53c of the intermittent relay 53 flows to the power source to generate a lock current, so that the wiper blade is set to a predetermined position. The wiper motor 55 continues to rotate until it reaches the stop position, and when the wiper blade reaches the predetermined stop position, the wiper motor 55 suddenly stops.

The relay drive circuit 52 is turned on again after a predetermined rest time, the movable contact 53b of the intermittent relay 53 is switched from the normally closed fixed contact 53c to the normally open fixed contact 53d, and the intermittent wiper switch 51 is turned on. While above, the above operation is repeated.

[0006]

[Problems to be solved by the device]

 In the wiper control device 50 described above, when the movable contact 53b of the intermittent relay 53 is in the normally closed fixed contact 53c and a lock current is flowing, the lock current of the wiper motor 55 is applied to the movable contact 53b and the normally closed fixed contact 53c. Therefore, when the movable contact 53b is switched from the normally closed fixed contact 53c to the normally open fixed contact 53d by turning on the relay drive circuit 52, if the voltage of the power supply is high, the movable contact 53b of the intermittent relay 53 or It is hard to say that an arc is not generated between the normally closed fixed contacts 53c, and if an arc occurs between the contacts, there is a possibility that contact welding or contact damage may occur. To solve the problem was a problem.

[0007]

[The purpose of the device]

 A wiper control device according to the present invention aims to provide a wiper control device having high reliability by preventing an arc from being generated between contacts of a relay.

[0008]

[Constitution of device]

[0009]

[Means for Solving the Problems]

 A wiper control device according to the present invention is characterized in that it is provided with a prohibition circuit for holding a timer time relay, which is assumed to generate a lock current of a wiper motor, in a stationary state, and a more preferable embodiment. At the relay drive transistor, the output terminal is connected to the base of the relay drive transistor, the first input terminal is connected to the emitter of the relay drive transistor, and the detection signal from the stop position detection means is input. A second input terminal is provided, and when the first input terminal is at the high level and the second input terminal is switched from the low level to the high level, the potential of the output terminal is set to the preset timer time low level. The present invention is characterized in that a holding circuit for holding is provided, and in a more preferable embodiment, the first input terminal is at a low level. When includes a prohibition circuit for holding the output regardless terminal to the level of the second input terminal to Hairebe Le.

[0010]

[Action]

 In the wiper control device according to the present invention, it is assumed that the lock current is applied to the wiper motor from the stop position detection means and the intermittent control means while switching the relay contacts by turning on the relay coil. Corresponding to, keep the relay immobile for the timer time of the inhibit circuit. Therefore, the relay contacts are neither opened nor closed while the lock current is flowing.

[0011]

【Example】

 An embodiment of the wiper control device according to the present invention will be described below with reference to FIGS.

The illustrated wiper control device 1 is mainly composed of a wiper motor 2, a wiper switch 3, a stop position detecting means 4, an intermittent control circuit 5, an inhibition circuit 6, and a washer motor 10.

As is clear from FIG. 2, a wiper blade 8 is connected to a motor shaft 2a provided in the wiper motor 2 via a link mechanism 7, and the rotational power of the motor shaft 2a is generated by the link mechanism 7. The wiper blade 8 reciprocates between the upper reversal position A1 of the wiping surface 9 and the lower reversal position A2, which is a predetermined stop position, because the wiper blade 8 is reciprocally swung on the wiping surface 9.

A power supply, a low speed terminal L of the wiper switch 3, and a high speed terminal H of the wiper switch 3 are connected to the power supply brush terminal 2b, the low speed brush terminal 2c, and the high speed brush terminal 2d provided in the wiper motor 2. ing.

A stop position detecting means 4 is integrally provided in the wiper motor 2, and a rotor 4 a provided in the stop position detecting means 4 is concentrically attached to a motor shaft 2 a of the wiper motor 2. There is.

The rotating body 4a provided in the stop position detecting means 4 has a first contact plate 4b and a first contact plate 4c which is formed on a part of the first contact plate 4b. Is provided with a second contact plate 4c, a first contactor 4d, and a second contactor 4e arranged in an electrically non-conducting region, and the first contact plate 4b is grounded. The first contactor 4d is connected to the power source, and the second contactor 4e is connected to the detection signal input terminal 5a provided in the intermittent control circuit 5.

The first contactor 4d contacts only the second contact plate 4c, and the second contactor 4e contacts the first contact plate 4b and the second contact plate 4c, respectively, and the wiper blade 8 moves. Both the first contactor 4d and the second contactor 4e are assembled so as to come into contact with the second contact plate 4c when the predetermined stop position A2 is reached.

When the motor shaft 2a of the wiper motor 2 rotates, the rotating body 4a also rotates. Therefore, while only the second contactor 4e is in contact with the first contact plate 4b, the second contactor 4e causes an earth circuit. Is formed, and the second contactor 4e is connected to the power source while the second contactor 4e is connected to the first contactor 4d on the second contact plate 4c, the second contactor 4e is connected to the power source. When the second contactor 4e is connected to the power supply, the low level detection signal is transferred to the intermittent control circuit 5 from the detection signal input terminal 5a.

The wiper switch 3 sets a stop mode, an intermittent mode, a low speed mode, a high speed mode, and a washer mode, respectively, and is provided with terminals I, E, M, L, H, and W to be connected corresponding to the modes. ing. The washer mode is set separately from the stop mode, the intermittent mode, the low speed mode, and the high speed mode.

The terminal H is connected to the high speed brush terminal 2d of the wiper motor 2, the terminal L is connected to the low speed terminal 2c of the wiper motor 2, and the terminal M is an intermittent power supply terminal 5b provided in the intermittent control circuit 5. , The terminal E is connected to the ground and a ground terminal 5c provided in the intermittent control circuit 5, the terminal I is connected to the intermittent input terminal 5d provided in the intermittent control circuit 5, and the terminal W is connected to the intermittent control circuit. 5 is connected to a washer input terminal 5f provided on the No. 5 and is also connected to one brush terminal 10a of the washer motor 10.

The wiper switch 3 connects the terminal L to the terminal M in the stop mode, connects the terminal I to the terminal E and connects the terminal M to the terminal L in the intermittent mode, and connects the terminal E to the terminal L in the low speed mode. Then, the terminal H is connected to the terminal E in the high speed mode, and the terminal E is connected to the terminal W in the washer mode.

On the other hand, the intermittent control circuit 5 includes a relay RL1, a relay driving transistor TR1, IC10, capacitors C1, C2, C3, resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, and a diode. D1 and a Zener diode ZD1.

One end of the resistor R1 is connected to the power supply terminal 5e provided in the intermittent control circuit 5, and the other end of the resistor R1 is connected to the terminal 9p of the IC10 and the IC10 via the capacitor C1. It is connected to the terminal 8p.

The cathode of the diode D1 is connected to the power supply terminal 5e, and the anode of the diode D1 is connected to the collector of the relay driving transistor TR1 via the resistor R2.

Then, one end of a relay coil RL1-1 provided in the relay RL1 is connected to the power supply terminal 5e, and also connected to a terminal 2p of the IC10 via a resistor R3 and a resistor R4. An intermittent input terminal 5d is connected to the connection point between R3 and the resistor R4.

The other end of the relay coil RL1-1 is connected to the collector of the relay driving transistor TR1, and the base of the relay driving transistor TR1 is connected to one end of the resistor R5 and one end of the resistor R6. Further, it is connected to the output terminal 6a provided in the prohibiting circuit 6.

The other end of the resistor R5 is connected to the other end of the resistor R1 and is also connected to the terminal 5p of the IC10 via the Zener diode ZD1 and the capacitor C2 which are connected in parallel, and further the resistor R7. It is connected to the terminal 1p of the IC 10 and is also connected to the washer input terminal 5f. The washer input terminal 5f is connected to one brush terminal 10a of the washer motor 10, and the other brush terminal 10b of the washer motor 10 is connected to a power source. The washer motor 10 injects the cleaning liquid stored in a washer tank (not shown) toward the wiping surface 9 from a nozzle (not shown) when energized.

The other end of the resistor R6 is connected to the emitter of the relay driving transistor TR1, the terminal 7p of the IC 10, and the first input terminal 6b provided in the inhibition circuit 6.

The detection signal input terminal 5a of the intermittent control circuit 5 is connected to a normally closed fixed contact RL1-2 which is a relay contact provided in the relay RL1 and also connected to a terminal 6p of the IC10 via a resistor R8. Has been done. The terminal 6p of the IC 10 is connected to the second input terminal 6b provided in the prohibiting circuit 6.

The intermittent power supply terminal 5b of the intermittent control circuit 5 is connected to movable contacts RL1-3, which are relay contacts provided in the relay RL1.

The earth terminal 5c of the intermittent control circuit 5 is connected to a normally open fixed contact RL1-4, which is a relay contact provided in the relay RL1, and is also connected to a terminal 4p of the IC10 via a resistor R9. , Is connected to the terminal 3p of the IC10 via the capacitor C3, and is connected to the terminal 5p of the IC10.

The terminal 1p of the IC10 is for washer input, the terminal 2p of the IC10 is for intermittent input operation, and the terminal 3p of the IC10 is for turning on / off the output from the terminal 7p of the IC10 by charging and discharging the capacitor C3. This is for threshold voltage recognition to set the intermittent time to operate.

The terminal 4p of the IC10 is for setting an intermittent time for setting an intermittent time together with the capacitor C3 by the resistor R9, the terminal 5p of the IC10 is for grounding, and the terminal 6p of the IC10 is for the capacitor C3. Is for switching between charging and discharging, and when this terminal 6p is at a low level, the capacitor C3 is discharged through the terminal 6p as a path.

The terminal 7p of the IC 10 is for output. When the terminal 7p becomes low level, the relay driving transistor TR1 is turned on, and when the terminal 7p becomes high level, the relay driving transistor TR1 is turned off. The terminal 8p of the IC 10 is for setting the output delay time, and the terminal 9p of the IC 10 is for the IC power supply.

Here, the prohibition circuit 6 is composed of an element including a timer, the first input terminal 6b is connected to the terminal 7p of the IC 10, and the second input terminal 6c is input with the detection signal via the IC 6p. Since it is connected to the terminal 5a, the first input terminal 6b detects the level of the terminal 7p of the IC 10, and the second input terminal 6c detects the potential of the movable contact 4e of the stop position detecting means 4, that is, the detection signal. Detect the electric potential.

In the prohibiting circuit 6, it is assumed that a lock current flows when the potential of the first input terminal 6b is high level and the potential of the second input terminal 6c is switched from low level to high level. The timer has a function of holding the potential of the output terminal 6a at a low level for a period of T1 until the timer is started by recognizing the state to be started and the time is up.

Further, the prohibiting circuit 6 has a function of holding the output terminal at the high level when the first input terminal is at the low level and the second input terminal is at the low level.

In the wiper control device 1 having such a structure, when the wiper switch 3 is switched to the intermittent mode at the B1 position as shown in FIG. 3, the terminal I of the wiper switch 3 is connected to the terminal E. , The earth circuit is formed in the intermittent input terminal 5d of the intermittent control circuit 5, the terminal 2p of the IC10 recognizes the intermittent input signal, and the terminal 7p of the IC10 is set to the low level, so that the relay driving transistor TR1 is turned on. Then, the capacitor C3 starts discharging and excites the relay coil RL1-1 of the relay RL1. When the relay coil RL1-1 is excited, the movable contact RL1-3 switches from the normally closed fixed contact RL1-2 to the normally open fixed contact RL1-4.

By switching to the intermittent mode of the wiper switch 3, the power source → the brush terminal 2b for the power source of the wiper motor 2 → the low speed brush terminal 2c of the wiper motor 2 → the terminal L of the wiper switch 3 → the terminal M of the wiper switch 3 → the intermittent operation The intermittent power supply terminal 5b of the control circuit 5 → the movable contact RL1-3 of the relay RL1 → the normally open fixed contact RL1-4 of the relay RL1 → the current flows to the ground and the motor shaft 2a of the wiper motor 2 starts to rotate.

When the motor shaft 2a of the wiper motor 2 starts to rotate, the wiper blade 8 is reciprocatingly wiped via the link mechanism 7 between the stop position A2 on the wiping surface 9 and the upper reversal position A1. Since the relay driving transistor TR1 is kept on until the capacitor C3 is discharged to an arbitrary potential, it is kept on even if the wiper switch 3 is switched to the stop mode at the B2 position.

Since the rotating body 4a of the stop position detecting means 4 also rotates due to the motor shaft 2a of the wiper motor 2 starting to rotate, the first contactor 4d and the second contactor 4e are separated from the second contact plate 4c. The second contactor 4e starts contacting the first contact plate 4b from the position B3. When the second contactor 4e comes into contact with the first contact plate 4b from the B3 position, the terminal 6p of the IC 10 and the second input terminal 6c of the inhibition circuit 6 switch from the high level to the low level at the B3 position.

Since the capacitor C3 finishes discharging at the position B4 and the terminal 7p of the IC10 becomes high level, the first input terminal 6b of the inhibition circuit 6 also becomes high level at position B4, and the relay driving transistor TR1 is turned off. Then, in order to demagnetize the relay coil RL1-1 of the relay RL1, the movable contact RL1-3 is restored from the normally open fixed contact RL1-4 to the normally closed fixed contact RL1-2, but the wiper blade 8 reaches the stop position A2. Until then, the second contactor 4e of the stop position detecting means 4 is in contact with the first contact plate 4b. Therefore, the power source → the power source brush terminal 2b of the wiper motor 2 → the low speed brush terminal of the wiper motor 2 2c → terminal L of wiper switch 3 → terminal M of wiper switch 3 → intermittent power supply terminal 5b of intermittent control circuit 5 → relay RL1 Moving contact RL1 3 → Normally closed fixed contact RL 1-2 of relay RL 1 → Detection signal terminal 5a of intermittent control circuit 5 → Second contactor 4e of stop position detecting means 4 → First contact of stop position detecting means 4 A current flows from the plate 4b to the ground, and the motor shaft 2a of the wiper motor 2 continues to rotate.

When the wiper blade 8 comes to the stop position A2, both the first contactor 4d and the second contactor 4e of the stop position detecting means 4 come on the second contact plate 4c, so that the motor shaft of the wiper motor 2 is stopped. 2a is suddenly stopped by electromagnetic braking, and the wiper blade 8 is stopped at the stop position A2.

At this time, if the wiper switch 3 is switched to the intermittent mode at the B5 position, both the first contactor 4d and the second contactor 4e of the stop position detecting means 4 are on the second contact plate 4c, and therefore the prohibition is prohibited. The second input terminal 6c of the circuit 6 is switched from the high level to the low level at the B3 position and then becomes the high level at the B5 position, and the first input terminal 6b is at the high level. The potential of 6a becomes low level for a preset T1 time.

When the potential of the output terminal 6a of the prohibiting circuit 6 becomes low level, the relay is performed with the first contactor 4d and the second contactor 4e of the stop position detecting means 4 on the second contact plate 4c. Since the driving transistor TR1 is held in the OFF state for T1 time, the relay RL1 does not perform switching of the movable contacts RL1-3 for the T1 time set by the prohibiting circuit 6.

After that, since the potential of the output terminal 6a of the prohibiting circuit 6 becomes high level at the position B6 when the set time T1 of the prohibiting circuit 6 has passed, the relay driving transistor TR1 is turned on at the position B6 and the relay driving transistor TR1 is turned on. Since the movable contact RL1-3 is switched from the normally closed fixed contact RL1-2 to the normally open fixed contact RL1-4 by exciting the relay coil RL1-1, the power supply → the power supply brush terminal 2b of the wiper motor 2 → the low speed of the wiper motor 2 Brush terminal 2c → terminal L of wiper switch 3 → terminal M of wiper switch 3 → intermittent control circuit 5 intermittent power supply terminal 5b → movable contact RL1-3 of relay RL1 → normally open fixed contact RL1-4 of relay RL1 → The electric current flows to the ground, the motor shaft 2a of the wiper motor 2 starts to rotate, and the wiper blade 8 causes the wiper motor 8 to stop at the stop position A2 and the upper portion. Wiping operation is performed by reciprocating between the reversal position A1.

Then, even when the wiper switch 3 is switched to the stop mode at the B7 position, the relay driving transistor TR1 continues to be turned on until the capacitor C3 is discharged to an arbitrary potential in the same manner as described above, and the stop position detecting means 4 operates. The first contactor 4d and the second contactor 4e are separated from the second contact plate 4c, and the second contactor 4e starts contacting the first contact plate 4b from the position B8.

Since the capacitor C3 finishes discharging at the position B9, the relay driving transistor TR1 is turned off and the relay coil RL1-1 is demagnetized, but the wiper blade 8 reaches the stop position A2 until the stop position A2 is reached. Since the second contactor 4e of the detecting means 4 contacts the first contact plate 4b, the energization path of the wiper motor 2 is formed and the motor shaft 2a is continuously rotated in the same manner as described above, and the wiper blade 8 is stopped. Stop at the position B10 when the position A2 is reached.

Further, as is clear from FIG. 4, when the wiper blade 8 is in the state in which the operation is restricted at the stop position A 2 due to a large amount of obstacles such as snowfall on the wiping surface 9, the wiper switch 3 After switching to the intermittent mode at the E1 position and then to the stop mode at the E2 position, the relay driving transistor TR1 is turned on by the discharge current of the capacitor C3 to excite the relay coil RL1-1 of the relay RL1. Since the wiper blade 8 is restrained at the stop position A2, the motor shaft 2a of the wiper motor 2 does not rotate.

After that, as the obstacle is removed at the E3 position, the motor shaft 2a of the wiper motor 2 starts to rotate at the same time, so that the second contactor 4e of the stop position detecting means 4 is located at the E4 position on the first contact plate 4b. Then, the second input terminal 6c of the prohibiting circuit 6 is switched from the high level to the low level in the same manner as described above, the energizing path of the wiper motor 2 is formed, and the wiper blade 8 stops on the wiping surface 9. A wiping operation is performed by reciprocating between the position A2 and the upper reversal position A1.

Since the relay driving transistor TR1 is turned off at the E5 position where the capacitor C3 is discharged to an arbitrary potential, the relay coil RL1-1 is demagnetized, and the first input terminal 6b of the prohibiting circuit 6 is set to the high level at the E5 position. Since the second contactor 4e of the stop position detecting means 4 contacts the first contact plate 4b until the wiper blade 8 reaches the stop position A2, the energizing path of the wiper motor 2 is set in the same manner as above. When the wiper blade 8 reaches the stop position A2 by continuously forming the motor shaft 2a and rotating it, the first contactor 4d and the second contactor 4e of the stop position detecting means 4 are both placed on the second contact plate 4c. At the E6 position, a lock current is generated to electromagnetically brake the motor shaft 2a of the wiper motor 2. The wiper blade 8 is stopped suddenly at the stop position A2.

Since the first contactor 4d and the second contactor 4e of the stop position detecting means 4 are both on the second contact plate 4c, the potential of the second input terminal 6c of the prohibiting circuit 6 is After switching from the high level to the low level at the E4 position, it becomes the high level at the E6 position, and the potential of the first input terminal 6b of the prohibiting circuit 6 becomes high because the relay driving transistor TR1 is turned off at the E5 position. Since it is at the level, the potential of the output terminal 6a of the prohibiting circuit 6 becomes low level for the preset T1 time.

When the output terminal 6a of the prohibiting circuit 6 is held at the low level, the relay driving transistor TR1 is not turned on and the relay coil RL1-1 of the relay RL1 is not excited, so the relay RL1 Prohibits switching of the movable contacts RL1-3 The T1 time set by the circuit 6 is not performed.

Further, as is apparent from FIG. 5, when the wiper switch 3 is switched in the stop mode and the washer mode is switched to the G1 position, the W terminal is connected to the E terminal, so the power source → the other of the washer motor 10 is connected. An electric current flows from the brush terminal 10b to the brush terminal 10a on one side of the washer motor 10 to the ground, and the cleaning liquid stored in the washer tank is sprayed from the nozzle toward the wiping surface 9.

At the same time, since the washer input terminal 5f of the intermittent control circuit 5 becomes low level, the terminal 1p of the IC10 also becomes low level, so that the terminal 7p of the IC10 becomes low level at the G2 position after the ON delay time. Then, the relay driving transistor TR1 is turned on to excite the relay coil RL1-1 of the relay RL1.

When the relay coil RL1-1 of the relay RL1 is excited, the movable contact RL1-3 is switched from the normally closed fixed contact RL1-2 to the normally open fixed contact RL1-4. Therefore, the power supply → the power supply brush terminal of the wiper motor 2 is connected. 2b → low speed brush terminal 2c of wiper motor 2 → terminal L of wiper switch 3 → terminal M of wiper switch 3 → intermittent power supply terminal 5b → movable contact RL1-3 of relay RL1 → normally open relay RL1 A current flows from the fixed contacts RL1-4 to the ground, and the motor shaft 2a of the wiper motor 2 starts to rotate, and the wiper blade 8 reciprocates between the stop position A2 on the wiping surface 9 and the upper reversal position A1 to perform a wiping operation. During the setting to the washer mode, the relay RL1 is kept in the ON state and the wiper motor 2 is continuously rotated.

When the washer mode setting is stopped at the G3 position after an arbitrary time, the washer input terminal 5f becomes high level, but the output off delay time of the terminal 7p of the IC10 is set longer by the capacitor C3 than at the intermittent time. Therefore, after that, the relay RL1 keeps the energization path of the wiper motor 2 and the front and rear wiper motor 2 rotates twice, and after a lapse of an arbitrary time, the second contactor 4e of the stop position detecting means 4 has the first contactor 4e. While contacting the contact plate 4b, the terminal 7p of the IC 10 switches from the low level to the high level at the G4 position, the relay RL1 turns off, and then the second contactor 4e contacts the first contact plate 4b. By forming the energizing path of the wiper motor 2, the wiper blade 8 stops when the wiper blade 8 reaches the stop position A2. Since the first contactor 4d and the second contactor 4e of the position detecting means 4 are both in contact with each other on the second contact plate 4c, the motor shaft 2a of the wiper motor 2 is suddenly stopped at the G5 position after the post-wiping time by electromagnetic braking. Then, the wiper blade 8 is stopped at the stop position A2.

Here, in the prohibiting circuit 6, the potential of the second input terminal 6c is switched from the low level to the high level at the G5 position, and the potential of the first input terminal 6b is switched from the low level to the high level at the G4 position. Since the level is switched to the level, the potential of the output terminal 6a becomes low level for T1 time up to the preset G6 position, the relay driving transistor TR1 is not turned on, and the relay RL1 is not turned on.

[0059]

[Effect of device]

 As described above, the wiper control device according to the present invention is provided with the prohibition circuit that detects the lock current of the wiper motor and keeps the relay in the inoperative state even if there is an input within the preset timer time. Because of the configuration, the relay is not activated while the lock current is flowing to the relay contacts, so arcing does not occur between the contacts even if the voltage of the power supply is high. Since there is no cause of contact damage or contact damage, it has an excellent effect of having high reliability.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of an embodiment of a wiper control device according to the present invention.

FIG. 2 is a schematic diagram illustrating an assembling relationship between a stop position detecting unit and a wiper of the wiper control device shown in FIG.

FIG. 3 is a time chart explaining the operation of the wiper control device shown in FIG.

FIG. 4 is a time chart explaining the operation of the wiper control device shown in FIG.

5 is a time chart explaining the operation of the wiper control device shown in FIG. 1. FIG.

FIG. 6 is a schematic circuit diagram of a conventional wiper control device.

[Explanation of symbols]

 1 wiper control device 2 wiper motor 3 wiper switch 4 stop position detection means 4e contact 5 intermittent control means 6 prohibition circuit RL1 relay RL1-1 relay coil RL1-2, RL1-3, RL1-4 relay contact T1 timer time TR1 for relay drive Transistor

Claims (3)

[Scope of utility model registration request] 1. A wiper switch for setting stop, intermittent, low-speed, and high-speed modes, a wiper motor for driving the wiper, and a contact for generating a detection signal when the wiper reaches a predetermined stop position. It has a stop position detecting means and a relay coil whose one end is connected to a power source and the other end is connected to the collector of a relay driving transistor, and a normally closed fixed contact is connected to the contact of the stop position detecting means. Is intermittent, the intermittent control means provided with a relay that intermittently forms a conduction path in the wiper motor by switching the relay contact, and a timer time the relay that is assumed to generate a lock current of the wiper motor. A wiper control device comprising a prohibition circuit for holding a stationary state. 2. A detection signal from the stop position detecting means, comprising an output terminal connected to the base of the relay driving transistor and a first input terminal connected to the emitter of the relay driving transistor. A second input terminal for inputting the voltage, the potential of the output terminal being preset when the first input terminal is at a high level and the second input terminal is switched from a low level to a high level. The wiper control device according to claim 1, further comprising a prohibition circuit for holding the timer at a low level for a time. 3. A prohibition circuit for holding an output terminal at a high level regardless of the level of the second input terminal when the first input terminal is at a low level. The described wiper control device.