JPS6325251Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a wiper drive circuit that operates in conjunction with a washer in a vehicle.

In ordinary cars, when the washer switch is turned on, the wipers start working in conjunction with each other after a certain period of time, but the time from when the washer switch is turned on until the cleaning liquid is sprayed out is However, since this differs depending on the length of time that has passed since the last time the washer was used, depending on the setting of the delay time, too much cleaning liquid may come out or the wiper may wipe dry. In other words, the time from when the washer switch is turned on until the cleaning liquid is sprayed out varies depending on the amount of liquid remaining in the cleaning liquid pipe, and the amount of remaining liquid decreases as time passes after using the washer, resulting in the above problem. Something happened.

The purpose of the present invention is to prevent the above-mentioned overflow of cleaning fluid and wiper wiping by preventing the wiper from wiping with too much cleaning fluid by changing the time from when the washer switch is turned on to when the wiper is activated, depending on how much time has passed since the last time the washer was used. The goal is to provide the following.

The present invention will be explained below using examples. In the figure, 1 is a washer motor for driving a washer pump to eject cleaning liquid, and 2 is a washer switch for driving the washer motor. On the other hand, 3 is a wiper relay controlled by the washer switch 2, and its contact 3a
is used to drive the wiper. A wiper motor 4 has interlocking self-holding contacts 4a, and has a low-speed brush 4b and a high-speed brush 4c. 5 is a wiper switch, and the movable contact 5a is set to stop (OFF),
It is possible to switch between low speed (Lo) and high speed (Hi).

The wiper relay 3 is controlled by a transistor _Q1 , which in turn is controlled by a transistor _Q2 , and _the latter transistor _Q2 is controlled by a watch switch 2. There is. That is, transistor Q ₂ is
By turning on the watch switch 2, the capacitor
After a time t ₁ determined by the time constant T ₁ = C ₂ · R ₃ of the circuit consisting of C ₂ , resistor R ₃ , and diode D ₀ , the base potential falls below a predetermined value and the watch switch 2 is turned on. After turning off, capacitor C ₂ , transistor Q ₂ emitter-base, and resistor
Time constant T ₂ of the circuit consisting of R ₄ = time determined by C ₂・R ₄
Turn off after t ₂ . In addition, watch switch 2
When turned on, transistor Q ₃ turns on after a time t ₃ determined by the time constant T ₃ = C ₁ · R ₁ of the circuit consisting of resistor R ₁ , diode D ₄ , capacitor C ₁ , and diode D ₁ After the power switch 2 is turned off, the capacitor C ₁ , the diode D ₂ , the emitter-base of the transistor Q ₃ , and the resistor
Time constant T ₄ of the circuit consisting of R ₂ = time determined by C ₁・R ₂
After t ₄ its transistor Q ₃ is turned off. resistance
_R5 and _R6 are for biasing transistor _Q1 .
Then, time t ₁ and t ₂ are about 2 seconds, t ₃ is about 3 seconds,
_t4 is set to approximately 5 minutes.

Next, the operation will be explained. The movable contact 5a of the wiper switch 5 is now stopped (OFF) as shown by the solid line.
It shall be in the position of Therefore, when the washer switch 2 is turned on, the washer motor 1 rotates and sprays cleaning water onto the front glass. and,
After that, when t ₁ (2 seconds) has elapsed, the transistor Q ₂ is turned on, and therefore the transistor Q ₁ is also turned on, the wiper relay 3 is energized, and its contact 3a is switched to the broken line side. Therefore, the low speed brush 4b of the wiper motor 4
When a current flows through the wiper motor 4, the wiper motor 4 starts rotating, and the wiper starts operating. Note that at this time, transistor _Q3 is also turned on.

Then, when the washer switch 2 is turned off, the washer motor 1 immediately stops and the jetting of washing water stops, but the transistor Q ₂ then turns off for a time t ₂
(2 seconds), so wiper relay 3
During that time, it continues to be energized, and the contact 3a also remains switched to the side indicated by the broken line. When the contact 3a returns to the side shown by the solid line after time _t2 has elapsed, if the contact 4a has switched to the side shown by the broken line at that time, the wiper motor 4 will stop when it returns to the side shown by the solid line.

After turning off watch switch 2, time t ₄
After more than (5 minutes) have passed, turn on the watch switch 2 again.
If it is turned on, the operation is exactly the same as above, but if it is turned on before the time _t4 elapses, the following operation will occur. In other words, watch switch 2
Even if the watch switch 2 is turned off, the charge in the capacitor C ₁ continues to flow between the emitter and base of the transistor Q ₃ and is discharged until time t ₄ elapses, so the watch switch 2 is turned off again during this period. When turned on, that transistor _Q3 turns on.

Therefore, the capacitor C ₂ has a charging path passing through the diode D ₃ and the transistor Q ₃ in addition to the charging path passing through the resistor R ₃ and the diode D 0, and the capacitor C ₂ has a charging path passing through the diode D ₃ and the transistor Q ₃ . ) to a predetermined amount, and transistor _Q2 turns on.

In other words, even if the washer switch 2 is turned off, there is still enough cleaning fluid left in the cleaning fluid pipe for a period of time _t4 as it gradually returns to the cleaning fluid tank. The wiper operation start timing is also earlier.

Therefore, even if the time t ₁ until the wiper starts operating in normal cases is set to a time that takes sufficient measures to prevent the wiper from wiping dry, if the cleaning liquid remains in the pipe within the time t ₄ . When the washer is activated again, the wiper can be activated at a prompt timing.

Although the above embodiments are based on a combination of time constant circuits, it goes without saying that the essential parts of the circuit shown in the figure can be performed by a microcomputer.

As described above, according to the present invention, it is possible to prevent dry wiping of the wiper and overflow of cleaning liquid when the washer is operated.

[Brief explanation of the drawing]

The figure shows a wiper drive circuit showing an embodiment of the present invention. 1... Washer motor, 2... Watcher switch, 3... Wiper relay, 4... Wiper motor, 5... Wiper switch.

Claims (1)

[Scope of utility model registration request] A washer switch that drives a washer motor and squirts cleaning liquid when the washer switch is turned on, and a first switch that can be timed to energize the wiper motor after a desired time after the washer switch is turned on.
The first timer means starts counting when the watch switch is turned on and turns off after a certain period of time, and when the watch switch is operated again during the time counting, the first timer means starts counting when the watch switch is turned on. and second timer means for shortening the wiper drive circuit.