JP3103012B2 - Wiper device control circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control circuit for a wiper device, and more particularly to a control circuit for a wiper device in which a wiper motor is driven for a predetermined time by a drive start signal.

[0002]

2. Description of the Related Art Conventionally, a wiper device for an automobile is provided with a mode in which a wiper blade is moved for a predetermined time by a switch operation in addition to a continuous reciprocating motion of the wiper blade. For example, there is a type in which the wiper blade is reciprocated several times in accordance with the washer liquid ejection by operating a washer switch.

[0003] For example, a circuit as shown in FIG. 4 is one that enables the operation in the washer interlocking mode. The operation of the circuit shown in FIG. 4 will be described below with reference to FIG. A position discriminating switch AS is connected to the wiper motor M connected to this circuit. The position discriminating switch AS is interlocked with the wiper motor M and brakes the wiper motor M to stop a wiper blade (not shown) at a predetermined position. The switching state is alternately determined so as to determine a braking state in which the wiper blade M reciprocates and a driving state in which the wiper motor M is driven to reciprocate the wiper blade.

First, when the washer switch SW is turned on and an operation start signal is output while the ignition switch IG connected to the positive terminal of the battery BT is on, an on signal is sent from the washer-linked timer circuit 21 to the drive circuit 22 for a predetermined time. Is output. While the ON signal is being output, the drive circuit 22 is turned on, the coil of the relay RY is excited, the relay RY is switched, connected to the power supply voltage via the ignition switch IG, and connected via the relay RY. A drive current flows through the wiper motor M. Then, the wiper motor M starts to rotate, and the wiper motor M continues to rotate until the washer interlock timer 21 times out. Note that, with the rotation of the wiper motor M, the position determination switch AS alternately switches between the braking range and the driving range.

By the way, the washer interlock timer 21 is
If the time is up when the position determination switch AS is in the drive range as shown by the imaginary line in FIG. 5, even if the relay RY is switched to the non-excitation state shown in FIG. A current flows through the wiper motor M, and the wiper motor M continues to rotate. Then, when the position determination switch AS is switched to the braking range, the current supply is cut off, and the wiper motor M stops, and the stop position can be designed in advance including idle running. However, when the time of the element of the washer interlocking timer 21 is up when the position determination switch AS is in the braking range as shown by the solid line in FIG. 5 due to the influence of the ambient temperature or the like, the wiper motor M is stopped at that time. As a result, there is a problem that the vehicle cannot be stopped at the predetermined position designed in advance.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned problems in the prior art, a main object of the present invention is to provide a control circuit which can drive a wiper motor for a predetermined time by an operation start signal. It is an object of the present invention to provide a control circuit of a wiper device that can always stop at a predetermined position regardless of a position of a wiper motor.

[0007]

According to the present invention, there is provided a timer circuit for outputting a timer signal for enabling a wiper motor to be driven for a predetermined time by an operation start signal.
A relay capable of supplying a drive current to the wiper motor via a closing contact at the time of excitation, a relay drive transistor which is turned on by the output of the timer signal to excite the relay, and positions of a drive range and a braking range of the wiper motor. A position discriminating switch that switches so as to be able to discriminate in conjunction with the wiper motor, and when the position discriminating switch is in the drive range discrimination, a drive current can be supplied to the wiper motor via a non-excitation closed contact of the relay. A position discriminating switch is connected to the non-energized closing contact, and an excitation closing contact signal input through the energizing closed contact of the relay and a braking state of the position discriminating switch are input in the braking state determination state. In order to turn on the relay drive transistor irrespective of the time-up of the timer circuit by the braking area determination signal, It is achieved by providing a control circuit of the wiper device, characterized in that with respect to the serial relay driving transistor provided relay excitation holding circuit provided in parallel to the timer circuit.

[0008]

In this manner, when the timer circuit times out while the wiper motor is being driven and the relay is being excited and the braking range is being determined, the relay drive transistor is turned on to hold the relay in the excited state. The relay drive transistor is turned on until the switching from the braking range determination state to the drive range determination state is performed, and the wiper motor drive state based on the excitation state of the relay is maintained. A drive current is supplied to the wiper motor via the motor, and braking / stopping can be performed from the time when the state is switched to the braking area determination state.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a preferred embodiment of the present invention.

FIG. 1 is a diagram showing a main part of a control circuit of a vehicle wiper device to which the present invention is applied. The present wiper device may be capable of selecting, for example, each mode of low-speed and high-speed continuous reciprocating motion, and a circuit for performing these operations is not shown. The present wiper device has a circuit for performing the intermittent operation mode and the washer interlocking mode as shown in the figure, in addition to the low speed / high speed mode. In the washer interlocking mode, the wiper blade is reciprocated a predetermined number of times during the washer injection.

As shown in FIG. 1, a control power supply line VL is connected to a positive terminal of a battery BT as a power supply via an ignition switch IG, and an operation start signal is supplied to the control power supply line VL. Washer interlock timer 1 via washer switch SW1
However, the intermittent operation timers 2 are connected in parallel with each other via an intermittent switch SW2 for issuing an operation start signal.

A coil of the relay drive transistor Tr1 and a coil of the relay RY are connected to the control power supply line VL. When the relay drive transistor Tr1 is turned on, the coil of the relay RY is excited. The control power supply line VL is connected to a normally open terminal NO, which is a closed contact at the time of excitation of the relay RY. The common terminal of the relay RY is connected to the voltage side terminal of the wiper motor M.

The wiper motor M is connected with a position discriminating switch AS of a two-position selection type so as to be switched in synchronization with the rotation of the motor. The position discriminating switch AS switches to a braking terminal (black circle in the drawing) side in a relatively narrow range of braking including the predetermined stop position of the wiper, and operates in a relatively wide range of driving during operation of the wiper. (White circle in the figure). The braking terminal of the position determination switch AS is connected to a ground terminal on the ground of the wiper motor M, and the drive terminal of the position determination switch AS is connected to the control power supply line VL. The common terminal of the position determination switch AS is connected to the normally closed terminal NC of the non-excitation closed contact of the relay RY.

The output terminals of the washer interlocking timer 1 and the intermittent operation timer 2 (which are grounded when the timer is turned on) are connected to the base of the relay driving transistor Tr1. The collector of the control transistor Tr2 forming the relay excitation holding circuit 3 is connected. The emitter of the control transistor Tr2 is a normally closed terminal N of the relay RY.
It is connected to C. Further, a node between the voltage side terminal of the wiper motor M and the common terminal of the relay RY is connected to the base of the control transistor Tr2.

The operation of the wiper device thus constructed will be described below with respect to the washer interlocking operation. When the washer switch SW1 is turned on, the washer interlocking timer 1 starts, and in a normal state, the time is up while the position determination switch AS is switched to the drive terminal side, as shown by the imaginary line in the time chart of FIG. Relay RY
Becomes de-energized. However, while the position determination switch AS is switched to the drive terminal side, a current can flow to the wiper motor M via the drive terminal and the normally closed terminal NC of the relay RY. When the AS is switched to the brake terminal side, the line is cut off and stops after a predetermined idle running. When the vehicle is stopped after the above-mentioned idle running starting from the switching, the wiper motor M is always kept at a predetermined position.
May stop.

Next, when the time-up time is extended for some reason such as a temperature change, the control is performed as shown by a solid line in FIG. As shown in the figure, if the position determination switch AS switches from the drive terminal side to the braking terminal side before the time-up, the emitter side is pulled up by the voltage applied through the drive side terminal of the position determination switch AS and turned off. The control transistor Tr2 in the state is turned on because its emitter is grounded via the braking terminal of the position determination switch AS.

If the time is up while the position determination switch AS is in the braking range determination state, the washer-linked timer 1 which becomes an ON signal to the relay drive transistor Tr1
The timer signal is turned off, but in the energized state of the relay RY, a current can flow through the control transistor Tr2 as shown by a broken arrow I in FIG. 1, so that the control transistor Tr2 keeps on and the relay drive transistor Tr
The energized state of the relay RY is maintained by turning on 1.

Next, when the position discriminating switch AS switches from the braking range discriminating state to the driving range discriminating state, the above-mentioned pull-up state is established, so that the control transistor Tr2 is turned off.
The relay drive transistor Tr1 is also turned off, and the relay RY
Becomes de-energized. In this state, current can flow to the wiper motor M via the drive terminal of the position determination switch AS and the normally closed terminal NC of the relay RY, so that the wiper motor M continues to rotate.

When the position determination switch AS is switched from the drive terminal side to the brake terminal side again, the vehicle can stop at a predetermined position through idle running in the same manner as in the normal state.

The above operation is not limited to the washer-linked operation mode. According to the present circuit, only the intermittent operation timer 2 is provided in parallel with the washer-linked timer 1 as shown in FIG. Can be similarly controlled.

In the above embodiment, the position discriminating switch A
Although the braking terminal is connected to the ground side and the drive terminal is connected to the power supply side, they may be connected in reverse, and an example is shown in FIG. In FIG. 3, the same parts as those in the above embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the embodiment shown in FIG. 3, the battery B is connected to the voltage terminal of the wiper motor M via an ignition switch IG.
The positive terminal of T is connected, and the ground terminal of wiper motor M is
The relay RY is connected so as to be grounded via the normally closed contact NC of the relay RY and the drive terminal of the position determination switch AS as described above. The braking terminal of the position determination switch AS is connected to the voltage terminal of the wiper motor M.

The normally open contact NO of the relay RY is grounded. The coil of the relay RY is connected to the control power supply line VL and the relay drive transistor Tr1 of the embodiment.
, And is excited when the relay drive transistor Tr3 is turned on.

A timer-on signal from each of the timers 1 and 2 is input to the base of the relay drive transistor Tr3. The timer-on signal turns on the relay drive transistor Tr3. A relay excitation signal by turning on the transistor Tr4 of the relay excitation holding circuit 3 can also be input in parallel. This relay excitation holding circuit 3
When a voltage signal for determining the braking range of the position determination switch AS and a ground signal when the normally open contact NO of the relay RY is closed are input, an ON signal similar to the timer ON signal is output.

The operation in the second embodiment is also performed as shown in the time chart of FIG. 2 of the above embodiment, only by reversing the respective voltage levels in the drive range and the braking range of the position determination switch AS. Therefore, the description is omitted.

[0026]

As described above, according to the present invention, in a wiper device that brakes and stops when the time is up and the driving range is switched from the driving range to the braking range, when the time is up in the braking range, the state of the state is changed. Since the relay drive transistor is turned on through the relay excitation holding circuit using the signal of the position determination means and the relay is held in the excited state, the braking stop due to time-up in the middle of the braking area does not occur, It is possible to perform normal braking / stopping from the time when the driving range is switched to the braking range, and it is possible to always stop at a predetermined position.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main part of a control circuit of a vehicle wiper device to which the present invention is applied.

FIG. 2 is a time chart showing an operation procedure of the wiper device according to the present invention.

FIG. 3 is a view showing a second embodiment and corresponding to FIG. 1;

FIG. 4 is a diagram showing a main part of a control circuit of a conventional automobile wiper device.

FIG. 5 is a time chart showing an operation procedure of the conventional wiper device.

[Explanation of symbols]

 1 Washer interlock timer 2 Intermittent operation timer 3 Relay excitation holding circuit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-238151 (JP, A) JP-A 7-33760 (JP, U) JP-A 59-182447 (JP, U) JP-A 58- 128161 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60S 1/08 B60R 16/02 645

Claims (1)

(57) [Claims] 1. A timer circuit that outputs a timer signal that enables a wiper motor to be driven for a predetermined time by an operation start signal, a relay that can supply a drive current to the wiper motor via a closing contact at the time of excitation, and an output of the timer signal. A relay drive transistor that turns on to excite the relay;
A position discriminating switch that switches in conjunction with the wiper motor so as to be able to discriminate the respective positions of a drive range and a braking range of the wiper motor; and The position discriminating switch is connected to the non-energized closing contact so that a drive current can be supplied to the wiper motor through the energized closing contact signal input via the energized closing contact of the relay and the position. A timer circuit is provided for the relay drive transistor so that the relay drive transistor is turned on regardless of the time-out of the timer circuit according to a brake range determination signal input in the brake state determination state of the determination switch. And a relay excitation holding circuit provided in parallel with the control circuit.