JPH05184173A - Wiper driver - Google Patents

Abstract

PURPOSE:To make the device such one as has an excellent responsibility, no operation noise, no generation of arc, and excellent durability and performs a chopping control by making it a noncontact device and to make an external form of the device compact by forming it with small number of semiconductor elements. CONSTITUTION:An output device having a passive device whose one end is connected between an output side of a first active element Tr1 and an input side of a first FET 10 and the other side connected between an output side of a second active element Tr2 and an input of a second FET 20 is provided in a driving device 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiper driving device used for wiping a wiping surface such as a windshield glass of an automobile with a wiper blade.

[0002]

2. Description of the Related Art Hitherto, as a wiper driving device for wiping a wiping surface of a windshield glass of an automobile with a wiper blade, a device described in Japanese Utility Model Publication No. 56-48941 has been known.

In the wiper drive device described in the above publication, the coil of the relay is turned on in synchronization with turning on of the switching transistor.

When the coil of the relay is turned on, the relay contact connected to the brush terminal of the wiper motor is switched to form an energizing path of the wiper motor, so that the wiper blade connected to the motor shaft of the wiper motor is wiped. It wiped the surface back and forth.

[0005]

However, in the above-mentioned conventional wiper drive device, since the energization path of the wiper motor is formed by the relay contacts of the relay, it is difficult to say that the response performance is excellent, and when the relay contacts make contact. There is a problem in that an operating noise may be generated and an arc may not be generated between the relay contacts. In addition, since it is weak against impact such as dropping, it has a problem in durability, and because it is a combination of a coil and a relay contact, it is difficult to reduce the external dimensions, and chopping control with a low voltage level is possible. There was a problem that it was not suitable for.

[0006]

SUMMARY OF THE INVENTION The problem to be solved by the invention is that when the energizing path of the wiper motor is formed by a relay, the response performance is deteriorated and the operation noise is generated, and the arc is generated and the durability is further deteriorated. The point is that it is not suitable for chopping control and the external size increases.

[0007]

[Constitution of the invention]

[0008]

A wiper drive device according to the present invention comprises a switch means for setting an arbitrarily selected mode, and a mode control means for outputting a signal corresponding to the mode set by the switch means. A driving means for operating the wiper motor by an output signal from the mode control means to control energization of the wiper motor. One end of the driving means is the output side of the first active element and the input side of the first FET. It is characterized in that an output stage having a passive element connected between the output side of the second active element and the input side of the second FET is provided, and the other end is more preferable. In a preferred embodiment, the passive element is a resistor, and the active element is a transistor. In a more preferred embodiment, the first FET is a P channel. In a more preferable embodiment, the first active element is a PNP type transistor and the second active element is an NPN type transistor. It is characterized by having a configuration that is, and by forming a contactless output stage, excellent response performance,
With no operating noise, no arcing, excellent durability, chopping control, and an output stage with a small number of semiconductor elements, the objective was to achieve a compact external shape.

[0009]

In the wiper drive device according to the present invention, the passive element has a function of driving the second FET together with the first active element, and the first active element has a function of not driving the first FET. Have. In addition, the passive element has a function of gradually driving the second FET from a non-driving state. Therefore, the wiper motor is controlled as a simple circuit module without contacts.

[0010]

1 and 2 show an embodiment of a wiper driving device according to the present invention.

The wiper drive device 1 shown in the figure is mainly composed of a switch means 2, a mode control means 3 and a drive means 4.

The switch means 2 is provided with a switch for setting each mode of wiper stop, wiper automatic operation, wiper intermittent operation, and wiper low speed (high speed) operation.

When the switch is operated, the output terminal 2a
The command of the set mode is transferred to the input terminal 3a provided in the mode control means 3 via the signal line 5 connected to the.

The mode control means 3 includes the input terminal 3
a, a ground terminal 3b, a fixed position stop signal input terminal 3c, an output terminal 3d, and a power supply terminal 3e are provided, and the signals input from the input terminal 3a and the fixed position stop signal input terminal 3c are processed and then output. A processing circuit for outputting a signal for operating the driving means from the terminal 3d is incorporated. This drive means operating signal is a trigger signal for turning on the third transistor Tr ₃ provided in the drive means 4 described later.

When a command for the wiper automatic operation mode is input from the switch means 2, the mode control means 3 outputs an output terminal when a raindrop detection signal (not shown) such as a raindrop sensor is received. The signal for operating the drive means is output from 3d.

When the wiper intermittent operation mode command is input from the switch means 2, the mode control means 3 sets a pause time arbitrarily set by the processing circuit (the pause time can be changed by a manual switch). Through the output terminal 3d, a drive means operating signal is intermittently output.

When the wiper low speed (high speed) operation mode command is input from the switch means 2, the mode control means 3 continuously outputs the drive means operation signal from the output terminal 3d.

Further, the mode control means 3 keeps the fixed-position stop signal input terminal 3c connected to the ground side when the command is interrupted while the command for each operation mode is input. The drive means operating signal is continuously output from the output terminal 3d, and the output is stopped when the fixed position stop signal input terminal 3c is connected to the power supply side.

The drive means 4 has an input terminal 4a connected to the output terminal 3d of the mode control means 3 via a signal line 6,
A ground terminal 4b and motor power supply terminals 4c and 4d are provided, and the first FET 10 and the second FET are mainly provided.
20, a transistor Tr ₁ which is a first active element, a second
A half-bridge circuit is composed of a transistor Tr ₂ which is an active element of the above and a passive resistor R which is a passive element.

The first FET 10 is a P-channel type, the second FET 20 is an N-channel type, the first transistor Tr ₁ is a PNP type, and the second transistor Tr ₂ is an NPN type.

One end of the passive resistance R is connected in series to the gate of the first FET 10 and the collector of the first transistor Tr ₁ , and the other end of the passive resistance R is connected to the gate of the second FET 20 and the second transistor. It is connected in series with the collector of Tr ₂ .

This passive resistance R is the second transistor T
When r ₂ is turned on and the first FET 10 is turned on, the first FE is synchronized with turning on of the first transistor Tr _1.
After turning off T10, the second FET 20 is turned on, and the second FET 20 is turned on in synchronization with the turning off of the first transistor Tr ₁ .
Cut off the FET20 of the first FET10
The first FET 10 is gradually turned on by the delay circuit formed by the capacitor provided in.

The source of the first FET 10 is connected to the motor power supply terminal 4c on one side, and the drain of the first FET 10 is connected to the motor power supply terminal 4d on the other side.

The source of the second FET 20 is connected to ground, and the drain of the second FET is connected to the motor power supply terminal 4d on the other side.

The emitter of the first transistor Tr ₁ is connected to the source of the first FET 10, and the base of the first transistor Tr ₁ is connected to the collector of the third transistor Tr ₃ via the resistor r1.

[0026] Between the first transistor Tr ₁ in the emitter and base connected resistor _{r 2,} in the emitter side of the connection point of the resistor _{r 2} resistor _{r 3} and the resistance _{r 4} through the second transistor Tr ₂ bases are connected.

A diode D ₁ is connected to the connection point of the resistors r ₃ and r ₄ and the collector of the third transistor Tr ₃ toward this collector, and the second transistor Tr ₃ is connected.
The base of ₂ is grounded via a resistor r ₅ .

The emitter of the third transistor Tr ₃ is connected to the ground, the base of the third transistor Tr ₃ is connected to the ground via the resistor r ₆ , and the input terminal 4a is connected via the resistor r _7. Are connected.

When the driving means 4 turns on the third transistor Tr ₃ , the first transistor Tr ₁ turns on, the second FET 20 turns on via the passive resistor R, and the power supply terminals 4c and 4d are connected. Generate an electric potential.

The power supply terminals 4c and 4d of the driving means 4 are connected to the power supply terminal 9 provided on the motor 9 through the power supply lines 7 and 8.
a and 9b are connected, and a power source is connected to one power source line 7.

On the other hand, the motor shaft 9 provided for the motor 9
A wiper blade 11 is connected to c via a link 12, and the wiper blade 11 is disposed between a stop position A (lower end reversal position) and an upper reversal position B of the windshield glass WG, which is a wiping surface, by rotation of the motor shaft 9c. Wipe the gap back and forth.

The motor 9 has a fixed position stop switch 9
In the fixed position stop switch 9d, the movable contact 9e of the fixed position stop switch 9d switches from the ground side contact 9f to the power source side contact 9g every rotation of the motor shaft 9c.

The movable contact 9e is a contact 9g on the power source side when the wiper blade 11 reaches the stop position A.
When the wiper blade 11 is not in the stop position A, it is switched to the ground contact 9f and is connected to the fixed position stop signal input terminal 3c of the mode control means 3.

Brush terminals 9h and 9i are connected to power supply terminals 9a and 9b of the motor 9, and one brush terminal 9
h is connected to the power source side contact 9g of the fixed position stop switch 9d.

The wiper drive device 1 having such a structure
Performs the operation shown in FIG.

In the initial state (position a shown in FIG. 2) in which the mode command from the switch means 2 is the wiper stop, the drive means operating signal is not output from the output terminal 3d of the mode control means 3. Therefore, the third transistor Tr ₃ of the driving means 4 is off.

At this time, the motor power supply terminal 4c of the drive means 4 → the resistor r ₃ → the resistor r ₄ → the resistor r ₅ is energized,
Since the second transistor Tr ₂ is on, the first FET 10 is on via the passive resistor R.

When the drive means operating signal is output from the output terminal 3d of the mode control means 3 at position b in response to the operation mode command from the switch means 2, the third transistor Tr ₃ of the drive means 4 is turned on.

When the third transistor Tr ₃ is turned on,
To be energized based → collector resistor r ₁ → third transistor Tr ₃ of the emitter → first transistor Tr ₁ of the motor power supply of the drive means 4 terminal 4c → first transistor Tr _1, the first The transistor Tr ₁ turns on.

At the same time, the second transistor Tr ₂ is turned off via the diode D ₁ , so that the first FET 1
In 0, the drain potential is cut off, and the first FET1
0 turns off.

When the first transistor Tr ₁ is turned on,
The second FET 20 is turned on via the passive resistance R.

When the second FET 20 is turned on, the potential of the power supply terminal 4d of the driving means 4 is lowered, so that one brush terminal 9h of the wiper motor 9 → the other brush terminal 9i of the wiper motor 9 is energized and the motor shaft 9c. To rotate.

When the motor shaft 9c rotates, the wiper blade 11 reciprocates between the stop position A and the upper reversal position B of the wiping surface WG via the link 12.

Therefore, the wiper blade 11 stops at the stop position A.
If the wiper stop mode is commanded by the switch means 2 when the switch means 2 does not exist, the mode control means 3 drives the fixed position stop signal input terminal 3c until the fixed position stop switch 9 switches from the ground side to the power supply side. The operation signal is continuously output, and the output is turned off when the fixed position stop signal input terminal 3c is switched to the power supply side.

At this time, the movable contact 9d of the fixed position stop switch 9 is switched to the contact 9g on the power source side, whereby one brush terminal 9h of the wiper motor 9 and the other brush terminal 9i of the wiper motor 9 are switched.
Since a closed loop is formed in the motor shaft 9c, the motor shaft 9c instantaneously stops and the wiper blade 11 is stopped at a predetermined stop position A.

At the C position, the output of the driving means actuating signal is turned off, and at the same time, the passive resistor R and the first FE are turned on.
The first FET 10 is gradually turned on and returns to the initial state by the delay circuit formed by the capacitor provided in T10 until reaching the position d.

In the embodiment of the wiper drive device according to the present invention, the wiper motor 9 is described as having one speed, but the wiper motor 9 is not limited to one speed.

[0048]

As described above, since the wiper drive device according to the present invention has the above-mentioned structure, it has no contact point as compared with the wiper motor in which the energizing path is formed by the relay. It is excellent in performance, eliminates operating noise, eliminates arcing, improves durability, and can perform chopping control, and because it has a simple circuit module, it has an excellent effect of making the external shape extremely compact. It plays.

[Brief description of drawings]

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

FIG. 2 is a time chart explaining the operation of the wiper drive device shown in FIG.

[Explanation of symbols]

1 wiper drive device 2 switch means 3 mode control means 9 wiper motor 10 first FET (P channel type) 11 wiper blade 20 second FET (N channel type) R passive element (resistor) (passive resistance) Tr ₁ first 1 active element (PNP type transistor) Tr ₂ 2nd active element (NPN type transistor) WG Wiping surface

Claims (4)

[Claims] 1. A switch means for setting an arbitrarily selected mode, a mode control means for outputting a signal corresponding to the mode set by the switch means, and an operating signal operated by an output signal from the mode control means. The wiper motor includes drive means for controlling energization, and one end of the drive means is connected to the output side of the first active element and the first active element.
An output stage having a passive element connected to the input side of the FET and having the other end connected between the output side of the second active element and the input side of the second FET. A wiper drive device. 2. The wiper driving device according to claim 1, wherein the passive element is a resistor and the active element is a transistor. 3. The first FET is a P-channel type,
The wiper drive device according to claim 1 or 2, wherein the second FET is an N-channel type. 4. The wiper drive device according to claim 1, wherein the first active element is a PNP type transistor and the second active element is an NPN type transistor. ..