JPH0742891Y2 - Intermittent wiper device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an intermittent wiper device for intermittently operating a wiper blade for wiping a window glass of a vehicle, and particularly, for stable intermittent operation even when the voltage suddenly changes. The present invention relates to an intermittent wiper device that can be performed.

[Conventional technology]

Conventionally, an intermittent wiper device of this type is disclosed in, for example, Japanese Patent Laid-Open No. 59-2.
Some of them were disclosed in 20086.

FIG. 2 is a diagram showing a main part of the circuit disclosed in the conventional art.

In the figure, a is a wiper motor, b is an auto stop switch, c is a relay contact, d is a relay coil, e and f are transistors, g is a capacitor, h or l is a resistor, m is a diode, and n is an intermittent wiper. Start switch,
o is a DC power supply.

The auto stop switch b is connected to the movable contact b1 when the wiper blade (not shown) is in the stop position and the run contact b2 when the wiper blade is not in the stop position. Was configured.

A charging / discharging circuit for determining an intermittent time is configured by the capacitor g and the resistor j, and the connection point p between the capacitor g and the resistor j is connected to the base of the transistor f via the starting switch n. It had been. Also,
The resistance k is set to be smaller than the value of the resistance j forming the charge / discharge circuit. Therefore, when the movable contact b1 of the auto stop switch b is connected to the run contact b3 when the start switch n is closed, the capacitor g has the run contact b3, the movable contact b1, the start switch n, the resistance k, When the movable contact b1 was connected to the stop contact b2 by being rapidly charged through the path of the diode m and the transistor f, the capacitor g was gradually discharged through the path of the resistor j, the movable contact b1 and the stop contact b2. . The transistor f was turned off during the discharging of the capacitor g, and the operation of the wiper motor a was stopped.

[Problems to be solved by the invention]

However, in the case of the above-mentioned conventional intermittent wiper device, when the wiper motor a is operating and the movable contact b1 of the auto stop switch b is connected to the run contact b3, another load with relatively large power consumption is operated. At that moment, the voltage of the DC power supply o etc. suddenly decreases and the charged capacitor g
The base electric potential of the transistor f is in a reverse biased state due to the electric charges.

Therefore, due to the sudden decrease in the voltage, the transistor f
Is turned off, the wiper motor a is temporarily stopped, and the wiper blade is temporarily stopped at the intermediate position during the wiping operation.

[Means for solving problems]

The present invention has been made in view of the above-mentioned problems, and an intermittent wiper device capable of maintaining stable intermittent operation even when the voltage applied to the intermittent wiper device may suddenly decrease. The purpose is to provide. As a means therefor, a configuration is provided in which a constant voltage circuit is connected between the auto stop switch and the charge / discharge circuit.

[Action]

The intermittent wiper device including the above-described means operates as follows.

That is, when the wiper motor rotates and the wiper blade is at the wiping position, the run contact of the auto stop switch is closed. When the run contact is closed, the constant voltage circuit applies a constant voltage to the charge / discharge circuit accordingly. Therefore, even if the applied voltage to the intermittent wiper device suddenly changes while the wiper motor is rotating, it does not affect the charge state of, for example, a capacitor in the charge / discharge circuit, and the wiper motor is temporarily stopped due to the rapid voltage change. Will be prevented.

〔Example〕

FIG. 1 shows an electric circuit diagram of a preferred embodiment of the present invention, and an embodiment will be described below based on the drawing.

In FIG. 1, reference numeral 1 is a wiper motor connected to a wiper blade (not shown) for wiping a window glass of a vehicle, which has a common terminal 11, a Hi terminal 12, and a Lo terminal 13.

Reference numeral 2 denotes an automatic stop switch that is interlocked with the wiper motor 1, and includes a stop contact 21 that is closed when the wiper blade is in the stop position, a run contact 22 that is closed when the wiper blade is in the wiping position, and a movable contact. Contact piece 23
have.

Further, 3 is a separately-excited timing means for starting a timed operation when the stop contact 21 of the automatic stop switch 2 is closed and stopping the operation of the wiper motor 1 for a predetermined time.

The timing means 3 will be described in detail.

The time limit means 3 is composed of a charge / discharge circuit 31, a first constant voltage circuit 32, a second constant voltage circuit 33 and an output circuit 34.

The charge / discharge circuit 31 is a circuit including a capacitor 311, a variable resistor 312, and a resistor 313. The capacitor 311 is connected to the first constant voltage circuit 32, and the resistor 313
Is connected to the second constant voltage circuit 33, and the connection point p between the capacitor 311 and the variable resistor 312 is connected to the terminal 42 of the wiper switch 4, respectively.

The first constant voltage circuit 32 is a circuit including a resistor 321 and a Zener diode 322. The resistor 321 is connected to the movable contact 23 of the auto stop switch 2 and the normally closed contact 345a of the relay contact 345 of the output circuit 34, and the cathode of the Zener diode 322 is connected to the positive electrode of the DC power source 6 via the ignition switch 5. The anodes are connected to the connection points Q of the capacitor 311 and the resistor 321 of the charge / discharge circuit 31, respectively.

The second constant voltage circuit 33 is a circuit including a resistor 331 and a Zener diode 332. And resistance 3
One end of 31 is grounded, and the connection point S of the Zener diode 332 with the anode is connected to the resistor 313 of the charge / discharge circuit 31,
The cathode of the Zener diode 332 is connected to the ignition switch 5.

Further, the output circuit 34 is a circuit including a transistor 341, a resistor 342, a diode 343, a relay coil 344, and a relay contact 345 having a normally closed contact 345a, a normally open contact 345b, and a movable contact piece 345c. Then, the transistor 34
The base of 1 is connected to the terminal 41 of the wiper switch 4 via the diode 343, the collector of the transistor 341 is connected to the relay coil 344, and the movable contact 345c of the relay contact 345 is connected.
Is connected to the terminal 43 of the wiper switch 4 and has a normally closed contact 345a.
Is connected to the first constant voltage circuit 32, and the normally open contact 345b is grounded.

Next, the wiper switch 4 will be described. The wiper switch 4 is a multistage switch provided in the vicinity of the driver's seat of the vehicle, and includes the time limiter 3 and the wiper motor 1 described above.
It has terminals 40 to 45 to be connected to. Then, an OFF position 46 for stopping the wiper motor 1 at a predetermined position, an INT position 47 for intermittently operating the wiper motor 1, an LO position 48 for continuously operating the wiper motor 1 at a low speed, and an HI position 49 for continuously operating the wiper motor 1 at a high speed. Of each switching position.

The terminals 43 and 44 are connected in the OFF position 46, the terminals 41 and 42 and the terminals 43 and 44 are connected in the INT position 47, the terminals 40 and 44 are connected in the LO position 48, and the terminals HI and 49 are connected. 40 and 45 are configured to connect.

The resistance value R1 [Ω] of the resistor 321 of the first constant voltage circuit 32
And the resistance value VR1 (Ω) of the variable resistor 312 of the charge / discharge circuit 31.
And the resistance value R2 (Ω) of the resistor 313 is R1 << VR1
It is set to + R2.

Therefore, the capacitor 311 is the auto stop switch 2
When the run terminal 22 is closed, the emitter and base of the transistor 341 of the output circuit 34, the diode 343, the terminals 41 and 42 of the wiper switch 4, the resistor 321 of the first constant voltage circuit 32, and the movable connection of the auto stop switch 2. It will be rapidly charged along the path of the strip 23 and the run terminal 22. Also, the capacitor 311
Is the stop terminal of the auto stop switch 2 when the stop terminal 21 of the auto stop switch 2 is closed.
21, the movable contact piece 23, the resistor 321 of the first constant voltage circuit 32, the variable resistor 312 of the charge / discharge circuit 31, the resistor 313, and the resistor 331 of the second constant voltage circuit 33 are gradually discharged.

Next, the operation of the embodiment having the above-mentioned configurations will be described.

For example, the case where the wiper switch 4 is switched to the INT position 47 in order to intermittently operate the wiper blade in the case of light rain will be described.

Immediately after switching the wiper switch 4 to INT position 47,
The base current is supplied to the transistor 341 of the output circuit 34 through the path of the diode 343, the wiper switch 4, the variable resistor 312, the resistor 313, and the resistor 331, and the transistor 341 is turned on. Transistor 34
When 1 is turned on, an exciting current is applied to the relay coil 344, and the normally open contact 345b of the relay contact 345 is closed. As a result, the Lo terminal 13 of the wiper motor 1 is grounded via the wiper switch 4 and the normally-open contact 345b, and the wiper motor 1 starts rotating. When the wiper motor 1 rotates a predetermined amount, the run contact 22 of the auto stop switch 2 is closed, and the capacitor 311 is rapidly charged via the run contact 22 as described above.

Then, while the run contact 22 is closed, the capacitor 31
1 and Zener diode 322 connection point Q and transistor 34
The Zener voltage VZ1 [V] of the Zener diode 322 is clamped between the connection points R of the emitters of 1. Therefore, even if the voltage of the current power source 6 or the like changes suddenly during this period, the potential between the connection point P and the connection point R does not change and the transistor 34
1 continues ON operation.

Next, when the wiper blade completes one reciprocating wiping operation, the stop contact 21 of the auto stop switch 2 is closed, and the potential of the connection point Q of the first constant voltage circuit 32 is raised to the same potential as the connection point R. . As a result, the potential of the connection point P becomes higher than the potential of the connection point R by the charging potential of the capacitor 311 and the base of the transistor 341 is in a reverse bias state, and the transistor 341 is turned off.

Thus, the exciting current of the relay coil 344 is stopped, the normally closed contact 345a of the relay contact 345 is closed, and the wiper motor 1
The common terminal 11 and the Lo terminal 13 are short-circuited by the auto stop switch 2, the relay contact 345 and the wiper switch 4, and the wiper motor 1 is suddenly stopped.

After the wiper motor 1 is stopped, the electric charge charged in the capacitor 311 is gradually discharged through the variable resistor 312, the resistor 313, and the resistor 331 of the second constant voltage circuit 33. And capacitor 3
The discharge of 11 progresses, and the potential of the connection point P changes to the transistor 341.
Transistor 341 when falling to the forward bias level of
Turns on again, the wiper motor 1 rotates again, and the wiper blade makes one reciprocating motion.

Thus, when the wiper switch 4 is switched to the INT position 47, the wiper motor 1 is intermittently operated at intervals controlled by the discharge time of the capacitor 311. Then, when the run contact 22 of the auto stop switch 2 is closed, that is, while the wiper motor 1 is rotating, the potential between the connection point Q and the connection point R is held at a constant voltage by the Zener diode 322, so that the voltage fluctuates rapidly. Even if there is, the rotation of the wiper motor 1 is not temporarily stopped.
Further, when the stop contact 21 of the auto stop switch 2 is closed, that is, when the wiper motor 1 is at rest, the potential between the connection point Q and the connection point S is kept constant by the Zener diode 332, so that the voltage varies. However, the discharge time of the capacitor 311 does not change, and the intermittent rest period does not change due to voltage fluctuation.

Note that the present invention is not limited to the above-described embodiments, and may have a circuit configuration combined with a control circuit of a washer motor, for example, and includes various embodiments.

[Effect of device]

This invention is characterized in that a constant voltage circuit is connected between the auto stop switch and the charging / discharging circuit, and the voltage applied to the intermittent wiper device such as the power supply voltage is relatively high in power consumption, such as a horn or a light. Even when the load fluctuates due to the operation of the load, it is possible to maintain a stable intermittent operation.

In particular, in this invention, the timing means has a charging / discharging circuit for setting a stop time, which is configured by connecting a capacitor and a resistor, an output circuit having a transistor, a zener diode and a resistance value compared to the resistance of the charging / discharging circuit. A constant voltage circuit connected with a small resistance, the base of the transistor and the movable contact piece of the auto stop switch are connected via the capacitor of the charge / discharge circuit and the resistance of the constant voltage circuit, and the transistor Since the emitter of is connected to the Zener diode of the constant voltage circuit, when the wiper blade is in the wiping position and the movable contact piece is connected to the run contact, the capacitor of the charging / discharging circuit rapidly moves through the resistance of the constant voltage circuit. To charge. Therefore, the capacitor of the charge / discharge circuit can complete charging in a short time when the wiper blade is in the wiping position. Moreover, since the capacitor is charged via the constant voltage circuit, the charge potential when the capacitor is completely charged can be kept constant, and the constant voltage circuit prevents surges from entering the time limit means from the auto stop switch. be able to.

In other words, the present invention inputs a signal from an external auto stop switch and responds to this by performing a timed operation.
It is possible to exert the effect peculiar to the so-called separately-excited intermittent wiper device, and even if a signal or a surge that causes voltage fluctuation is input from the external auto stop switch, the constant voltage circuit can effectively work on both of them. is there.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram showing a preferred embodiment of the present invention. FIG. 2 is an electric circuit diagram showing a conventional technique. 1 ... Wiper motor, 2 ... Auto stop switch,
3 ... Timer, 31 ... Charging / discharging circuit, 32 ... First constant voltage circuit, 33 ... Second constant voltage circuit.

Claims (1)

[Scope of utility model registration request] 1. A wiper motor (1) connected to a wiper blade of a vehicle, a movable contact piece (23) connected to the wiper motor (1), and a stop to which the movable contact piece (23) is connected when the wiper blade is at a stop position. An auto stop switch (2) having a contact (21) and a run contact (22) to which the movable contact (23) is connected when the wiper blade is in the wiping position, and a movable contact (23) of the auto stop switch (2). In the intermittent wiper device, which comprises a timing means (3) for starting a timed operation in response to the connection to the stop contact (21) and stopping the operation of the wiper motor (1) for a predetermined time. ) Is a capacitor (311) and a resistor (312,31
3) Charge / discharge circuit (3
1) and an output circuit (34) having a transistor (341)
And a Zener diode (322) and the charge / discharge circuit (31)
The resistance value is smaller than the resistance value (312,313) (321)
And a constant voltage circuit (32) connected to each other, and the base of the transistor (341) and the movable contact piece (23) of the auto stop switch (2) are connected to the capacitor (311) of the charge / discharge circuit (31). ) And the constant voltage circuit (32)
And the zener diode (322) of the constant voltage circuit (32) is connected to the zener diode (322) of the constant voltage circuit (32).