JPH10329652A - Wiper driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the current carried to a motor origin detecting switch, realize the simplification and miniaturization of a motor structure, and reduce the number of wires for motor connection. SOLUTION: This device is constituted in such a circuit that one end of the motor coil of a wiper motor 2 is connected to a ground, the other end of the motor coil of the wiper motor 2 is connected to the C-terminal of an electromagnetic relay 21, an N.O terminal of the electromagnetic relay 21 is connected to a power source, an N.C terminal of the electromagnetic relay 21 is connected to the ground, one end of the exciting coil 21a of the electromagnetic relay 21 is connected to the power source, and the other end of the exciting coil 21a of the electromagnetic relay 21 is connected to the ground by the on operation of an operation switch (wiper switch 1) or the non-detecting operation of a motor origin detecting switch 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for driving a wiper provided in a vehicle or the like, and more particularly to a wiper driving device capable of simplifying a wiper motor.

[0002]

2. Description of the Related Art Generally, a wiper driving device provided in a front window of a vehicle has a circuit configuration as shown in FIG. 8, and basically drives a wiper by a switching operation of a wiper switch 1 (operation switch). The power source is connected to the wiper motor 2 to drive the wiper. As the wiper motor 2, a motor having a motor origin detection switch 3 is usually used. The motor origin detection switch 3 is a wiper blade (not shown)
In order to always return to the predetermined stop position (usually the left end), it is detected that the rotation axis of the wiper motor 2 has returned to the origin position corresponding to this stop position, and conventionally, it is interlocked with the rotation axis of the motor. It consisted of sliding contacts. Hereinafter, a detailed configuration and operation of such a conventional wiper driving device will be described.

The conventional example shown in FIG. 8 does not perform intermittent driving of a wiper, and the wiper switch 1 is a two-contact type having a common terminal (hereinafter, referred to as a C terminal), an ON terminal and an OFF terminal. is there. This wiper switch 1
Is operated by the driver of the vehicle, etc., and turns off the C terminal.
Either an off state in which the terminals are connected or an on state in which the C terminal and the ON terminal are connected. One end of the motor coil of the wiper motor 2 is connected to the ground,
On the other hand, the other end of this motor coil is
Connected to terminal. In addition, O of the wiper switch 1
The N terminal is connected to a power supply via a vehicle ignition switch (not shown).

As shown in FIG. 8, a motor origin detection switch 3 has a C terminal and a normally open terminal (hereinafter referred to as N.
It is called O terminal. ) And normally closed terminals (hereinafter, referred to as
N. It is called C terminal. ), And in the detection state where the origin position is detected, the C terminal and the N.N. In a non-detection state in which the origin position is not detected, the terminal C and the N.C. The O terminal is connected. The C terminal of the motor origin detection switch 3 is connected to the OFF state of the wiper switch 1.
Terminal. The O terminal is connected to a power supply via an ignition switch together with the ON terminal of the wiper switch 1. The C terminal is connected to ground together with one end of the motor coil. The operating position of the wiper blade and the motor origin detection switch 3
FIG. 9 shows the relationship between the operating states of the respective sliding contacts.

In the above configuration, when the wiper switch 1 is turned on by operating the wiper switch 1 from the stop state as shown in FIG. 8 in a state where the ignition switch is turned on and power is supplied, FIG. As described above, the current i flows through the wiper motor 2, and the wiper starts. And
An operating state in which the rotation axis of the wiper motor has left the home position (ie, a state in which the wiper blade is not at the predetermined stop position).
In, the motor origin detection switch 3 is in a non-detection state,
As shown in FIG. The O terminal is closed.

For this reason, even if the wiper switch 1 is operated and turned off in such a state in which the origin is not detected, as shown in FIG. . The current i flows through the wiper motor 2 through the O terminal and the line passing through the C terminal and the OFF terminal of the wiper switch 1, and the operation of the wiper is continued. After that, when the rotation axis of the wiper motor returns to the home position (that is, when the wiper blade returns to the predetermined stop position), the motor home position detection switch 3 is in the detection state as shown in FIG. As a result, the path of the current i is cut off and the motor 2 stops.

At this time, the other end of the motor coil of the wiper motor 2 is connected to the C terminal of the motor origin detecting switch 3 and the N.C. C terminal and C terminal of wiper switch 1 and OFF
Since it is connected to the ground by a line passing through the terminal, a back electromotive force is generated as shown in FIG. 11D, and the wiper motor 2 is regeneratively braked and stops smoothly. Thus, the wiper blade always returns to the predetermined stop position and stops smoothly regardless of the position where the wiper switch 1 is turned off.

[0008] The conventional example shown in FIG.
Although this type does not perform the intermittent drive of the wiper, when the intermittent drive is performed, a circuit configuration as shown in FIG. 12, for example, has conventionally been used. Hereinafter, this will be described. Note that the same components as those of the device shown in FIG. 8 are denoted by the same reference numerals, and redundant description will be omitted. This device includes a wiper switch 11 having two sets of interlocking three-contact switches, an electromagnetic relay 12 for supplying power to the motor 2 at the time of intermittent driving or the like, and a transistor 13 for driving the electromagnetic relay 12. And ICs 14, 15, and 16 for outputting a drive signal for the transistor 13.

The wiper switch 11 has a C terminal and an OFF terminal.
It has two sets of three-contact type contact parts 11a and 11b each having a terminal, an INT terminal, and an ON terminal, and these two sets of switches are interlocked according to the operation of the same operation unit (not shown). The wiper switch 11 is operated by the driver of the vehicle or the like, and is turned off in which each C terminal is connected to an OFF terminal, intermittently turned on in which each C terminal is connected to an INT terminal, or each C terminal is connected to an ON terminal. Is connected to one of the continuous ON states. FIG.
The case of the intermittent ON state is shown. Then, one C terminal of the wiper switch 11 (the C terminal on the side of the contact portion 11a)
Terminal) is connected to the other end of the motor coil of the wiper motor 2, and one ON terminal is connected to a power supply via a vehicle ignition switch. The other C terminal of the wiper switch 11 (the C terminal on the side of the contact portion 11b) is connected to the ground, and the other OFF terminal is not connected.

The electromagnetic relay 12 includes an exciting coil 12a,
C terminal, N. O terminal and N. Contact part 12 having C terminal
b, and when the excitation coil 12a is not energized, the C terminal and the N.N. In the operating state in which the excitation coil 12a is energized, the C terminal is connected to the N.C terminal. The O terminal is connected. The C terminal of the electromagnetic relay 12 is connected to one of the OFF terminal and the INT terminal of the wiper switch 11. The O terminal is connected to a power supply via an ignition switch together with one end of the exciting coil 12a. The C terminal
It is connected to the C terminal of the motor origin detection switch 3.
The other end of the exciting coil 12a is connected to the ground via the transistor 13.

The IC 14 is a circuit for intermittently outputting a signal for intermittently driving the wiper (for example, a one-chip IC).
The input terminal is connected to the C terminal of the motor origin detection switch 3 and the output terminal is connected to the input terminal of the IC 15. The IC 14 has an enable signal input terminal (hereinafter, referred to as an E terminal), and the E terminal is connected to the other INT terminal of the wiper switch 11.

The IC 14 has a function of turning on an output signal (voltage H) as described below on condition that an enable signal is input. That is, when the enable signal is input, the output signal is turned on. However, when the input signal is turned on, the output signal is maintained in the off state (voltage L) for the intermittent drive stop time from that point on,
After that, it has a function of turning on the output signal (voltage H). In this case, since the polarity is inverted between the E terminal and the input terminal of the IC 14, the enable signal is turned on when the E terminal is connected to the ground side, and the input terminal is connected to the ground side. , The input signal is turned on. In this case, when the enable signal is off, the IC 14 keeps the output signal in the off state regardless of the state of the input signal.

The IC 15 is a so-called NOT circuit (a one-chip IC, for example) which is a kind of logic circuit, and inverts an output signal of the IC 14 and inputs the inverted signal to the IC 16. The IC 16 is a so-called NAND circuit (for example, a one-chip IC), which is a kind of logic circuit. The IC 16 uses the output voltage of the IC 15 and the voltage of the other ON terminal of the wiper switch 11 as input signals, Output drive signal. In this case, if the output signal of the IC 14 is turned on or the voltage of the other ON terminal of the wiper switch 11 is at the ground level, the output signal of the IC 16 is turned on and the transistor 13 is turned on. (Energized state).

In the above configuration, the wiper switch 1
When the switch 1 is operated to change from the off state to the continuous on state, a current flows through the wiper motor 2 via one of the C terminal and the ON terminal of the wiper switch 11, and the wiper is started. Then, in an operation state in which the rotation axis of the wiper motor has left the origin position, the motor origin detection switch 3 is in a non-detection state, and the N.O. O terminal is C
It will be in the state connected to the terminal.

Therefore, even if the wiper switch 11 is operated and turned off in such a state in which the origin is not detected, the C terminal of the motor origin detection switch 3 and the N.V. O terminal, the C terminal of the electromagnetic relay 12 and the N.V. The current i flows through the wiper motor 2 through the C terminal, and furthermore, the line passing through the C terminal and the OFF terminal of the wiper switch 11, and the operation of the wiper is continued. After that, when the rotation axis of the wiper motor returns to the origin position, the motor origin detection switch 3 enters the detection state, the path of the current i is cut off, and the motor 2 stops.

At this time, the other end of the motor coil of the wiper motor 2 is connected to one of the C terminal and the OFF terminal of the wiper switch 11, the C terminal of the electromagnetic relay 12 and the N.C. C terminal, the C terminal of the motor origin detection switch 3 and the N.C. Since the wiper motor 2 is connected to the ground by a line passing through the C terminal, the wiper motor 2 is also regeneratively braked and smoothly stops.

Next, when the wiper switch 11 is operated to change from the OFF state to the intermittent ON state, the aforementioned IC is connected via the other C terminal and the INT terminal of the wiper switch 11.
The E terminal 14 is connected to the ground, and an enable signal is input. Therefore, the output signal of the aforementioned IC 14 is turned on, the transistor 13 is operated and the electromagnetic relay 12 is operated, and the C terminal of the electromagnetic relay 12 and the N.C.
O terminal, one C terminal of the wiper switch 11 and I
Wiper motor 2
, A current i flows, and the wiper is activated.

Thereafter, in an operating state in which the rotating shaft of the wiper motor has left the origin position, the N.D. In the non-detection state in which the O terminal is connected to the C terminal, as in the case of the continuous operation described above, no matter where the wiper switch 11 is turned off, the wiper switch 11 always returns to the predetermined stop position and stops smoothly. Become.

Each time the rotation axis of the wiper motor returns to the home position, the N.P. Since the terminal C is in the detection state in which the terminal C is connected to the terminal C, and the input signal of the above-described IC 14 is turned on from the off state,
Is turned off for a predetermined stop time, and the switching operation of the transistor 13 causes the electromagnetic relay 12 to turn off.
Becomes inactive for this stop time. That is, when the rotation axis of the wiper motor returns to the home position, the electromagnetic relay 12
Terminal C and N. The C terminal is connected, and eventually the other end of the motor coil of the motor 2 is also grounded (the state shown in FIG. 12), and this state is maintained for a predetermined stop time. For this reason, the wiper blade once stops smoothly at the origin position, restarts after continuing the stopped state for a predetermined stop time, and realizes a predetermined intermittent operation.

[0020]

In any of the above-mentioned conventional wiper driving devices, when the wiper blade is returned to a predetermined stop position in any case, as shown in FIG. Since it is necessary to supply a motor current (large current) to the contact of the switch 3, the following inconvenience occurs. That is, it is necessary to adopt a conductive material that can withstand a large current as a material of the motor origin detection switch 3 and to make the current path thicker and to secure a large contact pressure and a large amount of deflection of the contact. There was a problem that it became expensive.

In addition, the conventional motor origin detection switch 3
Since it is necessary to flow a large current, it is arranged coaxially with the rotation axis of the motor and is composed of sliding contacts that interlock with this rotation axis. It was necessary to adopt a complicated and poorly assembling structure in which an O-ring for sealing the portion was provided coaxially with the rotation axis of the motor. Further, since it is a contact type, it is necessary to inject a large amount of grease for ensuring abrasion resistance, and it is also necessary to have a structure capable of filling the grease.

As can be seen from FIGS. 8 and 12, in the conventional circuit configuration, the number of electric wires to be connected to the motor is four.
Since there are many books, wiring costs and man-hours for wiring work depended on that much. Therefore, from such a point, the size of the motor is increased, the productivity and the assembling workability are deteriorated, and the cost is further increased.

Accordingly, the present invention provides a wiper driving device having a configuration capable of reducing the current flowing through the motor origin detection switch, simplifying and miniaturizing the motor structure, and reducing the number of motor connection lines. It is intended to provide.

[0024]

According to a first aspect of the present invention, there is provided a wiper driving device for detecting a wiper motor at an origin position, and for instructing operation of the wiper. A wiper driving device for driving the wiper by connecting the wiper motor to a power supply in accordance with the operation state of the operation switch or the motor origin detecting means, wherein power is supplied to the wiper motor by an electromagnetic relay. , FET or boost circuit, wherein the electromagnetic relay, FET or boost circuit is driven by an ON operation of the operation switch or a non-detection operation of the motor origin detecting means. .

According to a second aspect of the present invention, there is provided a wiper driving device comprising: motor origin detecting means for detecting that the wiper motor is at the origin position; and an operation switch for instructing the operation of the wiper. In a wiper driving apparatus for driving a wiper by connecting a wiper motor to a power supply according to an operation state of a motor origin detecting means, an electromagnetic relay having a common terminal, a normally open terminal and a normally closed terminal is provided, and a motor coil of the wiper motor is provided. Is connected to ground, the other end of the motor coil of the wiper motor is connected to a common terminal of the electromagnetic relay, a normally open terminal of the electromagnetic relay is connected to a power supply, and a normally closed terminal of the electromagnetic relay is grounded. To one end of the exciting coil of the electromagnetic relay as a power supply. As well as continue, the other end of the exciting coil of the electromagnetic relay, characterized in that the non-detection operation is connected to the ground by the configuration of the on-operation or the motor origin detector of the operation switch.

According to a third aspect of the present invention, there is provided a wiper driving device comprising: motor origin detecting means for detecting that the wiper motor is at the origin position; and an operation switch for instructing the operation of the wiper. In a wiper driving device that drives a wiper by connecting a wiper motor to a power supply according to an operation state of a motor origin detecting unit,
A channel FET and an N-channel FET are provided, one end of a motor coil of the wiper motor is connected to ground, the other end of the motor coil of the wiper motor is connected to a power source via the P-channel FET, and
It is connected to the ground via a channel FET, and the gate terminal voltages of the P-channel FET and the N-channel FET are set to the ground level by the on operation of the operation switch or the non-detection operation of the motor origin detecting means. It is characterized by.

According to a fourth aspect of the present invention, there is provided a wiper driving device comprising: motor origin detecting means for detecting that the wiper motor is at the origin position; and an operation switch for instructing the operation of the wiper. In a wiper driving device that drives a wiper by connecting a wiper motor to a power supply according to an operation state of a motor origin detection unit, a booster circuit and an N-channel FET are provided, and one end of a motor coil of the wiper motor is connected to ground; The other end of the motor coil of the wiper motor is connected to a power supply via the booster circuit and to the ground via the N-channel FET, and the booster circuit turns on the operation switch or operates the motor. It is driven by the non-detection operation of the origin detection means to be in a boosted state, and the N-channel FET Over preparative terminal voltage, characterized in that the non-detection operation at the ground level by the configuration of the on-operation or the motor origin detector of the operation switch.

According to a fifth aspect of the present invention, in the wiper driving device, a non-contact sensor is provided as the motor origin detecting means.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. First Example First, a first example of the present invention (a case where an electromagnetic relay is used and intermittent driving is not performed) will be described with reference to FIGS. Note that the same components as those in the conventional example shown in FIG. 8 are denoted by the same reference numerals, and redundant description will be omitted. As shown in FIG. 1, the wiper driving device of this embodiment has a configuration provided with an electromagnetic relay 21 and employs a motor origin detecting switch 22 (motor origin detecting means) composed of a non-contact type sensor.

The electromagnetic relay 21 includes an exciting coil 21a,
C terminal, N. O terminal and N. Contact part 21 having C terminal
b, and in a non-operating state in which the excitation coil 21a is not energized, the C terminal and the N.B. When the terminal C is connected and the excitation coil 21a is energized, the terminal C is connected to the terminal N. The O terminal is connected. The C terminal of the electromagnetic relay 21 is connected to the other end of the motor coil of the wiper motor 2. The O terminal is connected to a power supply via an ignition switch together with one end of the exciting coil 21a. The C terminal is connected to the ground. The other end of the exciting coil 21a is connected to the C terminal of the wiper switch 1.

The ON terminal of the wiper switch 1 is connected to the ground, and the wiper switch 1 is turned off.
The terminal is connected to a C terminal of a motor origin detection switch 22 described later.

The motor origin detecting switch 22 is not a sliding contact type, but a proximity sensor composed of, for example, a magnet and a reed switch (high frequency oscillation type, capacitance type), a proximity sensor composed of a magnet and a Hall IC, Alternatively, the contact point is switched by detecting the origin position of the motor rotation shaft in a non-contact manner by using a photoelectric rotation position sensor including a photo interrupter and a slit.

The motor origin detection switch 22 is also connected to the C terminal and the N.P. O terminal and N. In the detection state where the terminal position is detected, the C terminal and the N.C.
In a non-detection state in which the origin position is not detected, the terminal C and the N.C. The O terminal is connected. The C of the motor origin detection switch 22
The terminal is connected to the OFF terminal of the wiper switch 1 as described above. The O terminal is connected to the ground together with one end of the motor coil of the wiper motor 2. Note that N.I. The C terminal is in a disconnected state in this case. In addition, N. A two-terminal contact without a C terminal may be used. The relationship between the operating position of the wiper blade and the operating state of each contact of the motor origin detection switch 22 is as follows.
This is the same as the conventional one shown in FIG.

In the driving device having the above-described circuit configuration, the other end of the exciting coil 21a of the electromagnetic relay 21 is connected to the ground by turning on the wiper switch 1 (operation switch) or not detecting the motor origin detection switch 22. As a result, a current flows through the exciting coil 21a to operate the wiper motor 2, so that the following operation similar to the conventional operation is realized.

That is, when the wiper switch 1 is operated from the stop state as shown in FIG. 1 to the ON state while the ignition switch is ON and power is supplied,
When a current flows through the exciting coil 21a, the C terminal of the electromagnetic relay 21 and the N.C. FIG. 2 shows an operation state in which the O terminal is connected.
As shown in (a), a current i flows through the wiper motor 2, and the wiper starts. When the rotation axis of the wiper motor 2 is away from the origin position, the motor origin detection switch 22 is in a non-detection state, and as shown in FIG. The O terminal is closed.

Therefore, even if the wiper switch 1 is operated and turned off in such a state where the origin is not detected, as shown in FIG. . A current flows through the exciting coil 21a by the line passing through the O terminal and the C terminal and the OFF terminal of the wiper switch 1, and the electromagnetic relay 21 is activated. Also, the current i flows through the wiper motor 2 and the operation of the wiper is started. To be continued. At this time, the current i of the wiper motor 2 flows on the same route as in the normal operation shown in FIG.

Then, when the rotating shaft of the wiper motor returns to the home position, the motor home position detection switch 22 is in the detecting state as shown in FIG. 3D, and the current of the exciting coil 21a is cut off to stop the electromagnetic operation. The relay 21 is deactivated, whereby the current i is cut off and the motor 2 stops.

At this time, the other end of the motor coil of the wiper motor 2 is connected to the C terminal of the electromagnetic relay 21 and the N.C. Because it is connected to the ground by the line passing through the C terminal,
As shown in FIG. 3D, a back electromotive force is generated, and the wiper motor 2 is regeneratively braked and smoothly stops. Thus, the wiper blade always returns to the predetermined stop position and stops smoothly regardless of the position where the wiper switch 1 is turned off.

Therefore, according to the wiper driving apparatus of the present embodiment, although the wiper can be operated in the same manner as in the prior art, the motor origin detection switch 22 has only a small current flowing through the exciting coil 21a of the electromagnetic relay 21. Not flowing. For this reason, since it is not necessary to employ a conductive material that can withstand a large current as a material of the motor origin detection switch 22, it is not necessary to make the current path thick, and it is not necessary to secure a large contact pressure or a large amount of contact deflection. The size and cost of the motor can be reduced.

In addition, the motor origin detection switch 2 of this embodiment
Since it is not necessary to flow a large current, 2 is constituted by the non-contact type sensor as described above in this case. This simplifies the waterproof structure and eliminates the need to fill grease. In addition, as shown in FIG. 1, the number of lines to be connected to the motor origin detection switch 22 is one (two in the related art shown in FIGS. 8 and 12), so that it is necessary to connect to the wiper motor 2. The total number of lines is reduced from the conventional four lines to three lines. Therefore, from such a point, the motor can be further reduced in size, and its productivity and assembling workability can be improved, and further, the cost can be reduced.

Second Example Next, a second example of the present invention (in the case where an FET is used and intermittent driving is not performed) will be described with reference to FIGS.
The same components as those in the first example are denoted by the same reference numerals, and redundant description will be omitted. The wiper driving device of the present example is shown in FIG.
As shown in FIG. 7, a configuration is provided in which a P-channel FET 31, an N-channel FET 32, and a resistor 33 are provided instead of the electromagnetic relay 21 of the first example.

The FETs 31 and 32 are so-called field effect transistors. In this case, for example, a power MOSFET (Metal Oxide Semi) capable of switching a large current circuit.
conductor Field Effect Transistor). In this case, the FET 31 is a P-channel type, and when the gate terminal voltage becomes the ground level, conduction between the source and the drain is established. The FET 32 is an N-channel type. Conversely, when the gate terminal voltage becomes H level, conduction between the source and the drain is established.

In this case, the other end of the motor coil of the wiper motor 2 is connected to the power supply via a P-channel FET 21 and to the ground via an N-channel FET 32. In addition, these FET31,
All 32 gate terminals are connected to the C terminal of the wiper switch 1 and to the power supply via a resistor 33.

In the driving device having the above circuit configuration, F
The gate terminal voltage of ET31, ET32 is
Of the wiper motor 2 or the non-detection operation of the motor origin detection switch 22, and the wiper motor 2 operates by being connected to the power supply via the FET 31, thereby achieving the same operation as the conventional one.

That is, when the wiper switch 1 is operated to be turned on, the gate terminal voltages of the FETs 31 and 32 become the ground level, and the FET 32 is turned off while the FET 32 is turned off. As shown, a current i flows through the wiper motor 2, and the wiper starts. Then, in an operation state in which the rotation axis of the wiper motor 2 has left the origin position, as shown in FIG. The O terminal is closed.

Therefore, even if the wiper switch 1 is operated and turned off in such a state where the origin is not detected, as shown in FIG. . Each FE is connected by a line passing through the O terminal and the C terminal and the OFF terminal of the wiper switch 1.
The gate terminals of T31 and T32 are connected to the ground, the current i also flows through the wiper motor 2 along the same path as during normal operation, and the operation of the wiper is continued.

Then, when the rotation axis of the wiper motor 2 returns to the origin position, the motor origin detection switch 22 is in the detection state as shown in FIG.
The gate terminal voltages of the gates 31 and 32 become H level, whereby the current i is cut off and the motor 2 is stopped.

At this time, since the other end of the motor coil of the wiper motor 2 is connected to the ground via the FET 32, a back electromotive force is generated as shown in FIG. The brake stops smoothly. Thus, the wiper blade returns to the predetermined stop position and stops smoothly regardless of the position where the wiper switch 1 is turned off.

Therefore, according to the wiper driving device of the present embodiment, the motor origin detection switch 22 is connected to the resistor 33 while the conventional wiper operation is enabled.
Only a small current flows through the battery. Therefore, the same effect as in the first example can be obtained. Further, according to this example, F
Since the circuits are switched by the switching operation of the ET, a sound such as the relay operation sound of the electromagnetic relay of the first example is not generated, and an inherent effect of being quiet is obtained.

The operation of removing an unpleasant sound by using such an FET is particularly effective in a mode in which intermittent driving is performed. This is because, in the case where an intermittent drive is performed as in a third example described later, when an electromagnetic relay is used, a relay operating sound is generated each time the wiper intermittently operates, but an FET is used instead of the electromagnetic relay. This is because such an unpleasant sound is completely eliminated.

Third Example Next, a third example of the present invention (a case where an electromagnetic relay is used and intermittent driving is performed) will be described with reference to FIG. Note that the same components as those in the first example and the conventional example shown in FIG. 12 are denoted by the same reference numerals, and redundant description will be omitted. As shown in FIG. 7, the wiper driving device of this example includes a wiper switch 41 having one set of three-contact switches, an electromagnetic relay 21 for supplying power to the motor 2, and a drive for driving the electromagnetic relay 21. Transistor 13 and this transistor 13
And ICs 14, 15, and 42 for outputting the drive signals of. Further, a switch 22 similar to the first example is provided as a motor origin detection switch.

The wiper switch 41 has a C terminal, OFF
Terminal, INT terminal and ON terminal, C terminal and OFF terminal
One of an off state in which the terminals are connected, an intermittent on state in which the C terminal and the INT terminal are connected, and a continuous on state in which the C terminal and the ON terminal are connected. FIG. 7
Shows the case of the intermittent ON state. The C terminal of the wiper switch 41 is connected to the ground, the INT terminal is connected to the E terminal of the IC 14, the ON terminal is connected to the input terminal of the IC 42, and the OFF terminal is not connected.

In this case, the exciting coil 2 of the electromagnetic relay 21
The other end of 1a is connected to ground via transistor 13. The input terminal of the IC 14 is connected to the C terminal of the motor origin detection switch 22, and the E terminal is connected to the INT terminal of the wiper switch 41 as described above.

The IC 42 has three input terminals of NAN.
D circuit (for example, a one-chip IC), and the output voltage of the IC 15 and the O
The voltage of the N terminal and the voltage of the C terminal of the motor origin detection switch 22 (the voltage of the input terminal of the IC 14) are input signals,
A drive signal for the transistor 13 is output. In this case, I
When the output signal of C14 is in the ON state, or the voltage of the ON terminal of the wiper switch 41 or the voltage of the C terminal of the motor origin detection switch 22 is at the ground level, the output signal of the IC 42 is turned on. , The transistor 13 is turned on (energized state).

In the driving device having the above circuit configuration, the other end of the exciting coil 21a of the electromagnetic relay 21 is turned on by the wiper switch 41 (continuous on or intermittent on) or by the non-detection operation of the motor origin detection switch 22. Since the wiper motor 2 is connected to the ground and the current flows through the exciting coil 21a to operate the wiper motor 2, the following operation (including intermittent operation) similar to the related art is also realized.

That is, when the wiper switch 41 is operated to change from the OFF state to the continuous ON state, one of the inputs of the IC 42 becomes the ground level via the C terminal and the ON terminal of the wiper switch 41, so that the output signal of the IC 42 When the transistor 13 is turned on, the electromagnetic relay 21 is activated.
Is activated, and the C terminal of the electromagnetic relay 21 and the N.V. A current flows through the wiper motor 2 via a line passing through the O terminal, and the wiper starts. Then, in an operation state in which the rotation axis of the wiper motor has left the origin position, the motor origin detection switch 22 is in a non-detection state, and the N.O. The O terminal is connected to the C terminal.

Therefore, even if the wiper switch 41 is operated and turned off in such a state where the origin is not detected, the C terminal of the motor origin detection switch 22 is connected to the ground. When the output signal is turned on, the transistor 13 operates and the electromagnetic relay 21
Is activated, and the operation of the wiper is continued. At this time, the current of the wiper motor 2 flows on the same path as during normal operation, and does not flow to the motor origin detection switch 22.

Thereafter, when the rotation axis of the wiper motor returns to the origin position, the motor origin detection switch 22
Is in the detection state, the electromagnetic relay 21 is deactivated, and the motor 2 stops. At this time, the wiper motor 2
Are connected to the C terminal of the electromagnetic relay 21 and the N.C. Since the wiper motor 2 is connected to the ground via the C terminal, the wiper motor 2 is also regeneratively braked and smoothly stops.

Next, when the wiper switch 41 is operated to change from the OFF state to the intermittent ON state, the E terminal of the IC 14 is connected to the ground via the C terminal and the INT terminal of the wiper switch 41, and an enable signal is input. You.
As a result, the output signal of the IC 14 is turned on, the transistor 13 is activated, the electromagnetic relay 21 is activated, and the wiper is also activated.

Thereafter, in an operation state in which the rotation axis of the wiper motor has left the origin position, the motor origin detection switch 22
N. In a non-detection state in which the O terminal is connected to the C terminal, as in the case of the above-described continuous operation, no matter where the wiper switch 41 is turned off, the wiper switch 41 always returns to the predetermined stop position and stops smoothly. Become.

Each time the rotation axis of the wiper motor returns to the home position, the N.O. The C terminal is connected to the C terminal in a detection state, and the input signal of the IC 14 changes from the off state to the on state. Therefore, the output signal of the IC 14 is turned off for a predetermined stop time, and the switching operation of the transistor 13 causes the electromagnetic relay 21 to turn off. It is inactive for this stop time. That is, when the rotation axis of the wiper motor returns to the home position, C
Terminal and N. The C terminal is connected, and eventually the other end of the motor coil of the motor 2 is also grounded (the state shown in FIG. 12), and this state is maintained for a predetermined stop time. Therefore, a predetermined intermittent operation is realized as in the conventional example.

Therefore, according to the wiper driving device of this embodiment, the operation of the wiper (including the intermittent operation) as in the prior art is enabled, but the motor origin detection switch 22 is used to drive the IC 14 or the IC 42. Only a small current flows. For this reason, the same effect as in the first example can be obtained even in the case of having the intermittent drive function.

The present invention is not limited to the above-described embodiment, and may have various aspects. For example, it goes without saying that a wiper driving device having an intermittent driving function may be configured using an FET as in the second example instead of the electromagnetic relay in the third example. Further, a booster circuit may be used instead of the P-channel FET. In addition, it receives signals from operation switches and motor origin detection means, and receives electromagnetic relays and FETs.
A control unit (for example, a microcomputer) for driving the wiper motor 2 may be provided to control the start / stop of the wiper motor 2 as in the above embodiment.

[0064]

According to the wiper driving device of the first aspect,
The electromagnetic relay, the FET, or the booster circuit is driven by the ON operation of the operation switch or the non-detection operation of the motor origin detecting means, whereby a current flows to the wiper motor to drive the wiper. Therefore, even if the wiper is started by the operation of turning on the operation switch and the operation switch is turned off in the home position non-detection state, the operation of the wiper is continued by the operation of the motor home position detection means and the electromagnetic relay, FET or booster circuit. However, when the home position is detected, the current of the motor is cut off and the wiper stops, so that the conventional wiper operation can be performed.

At this time, the motor current always flows through the electromagnetic relay, FET or booster circuit, and there is no need to supply a large current to the motor origin detecting means. Therefore, according to the wiper driving device of the present invention, it is necessary to adopt a conductive material that can withstand a large current as a material of the motor origin detecting means, to make the current path thicker, and to reduce the contact pressure and the amount of deflection of the contact. Since it is not necessary to secure a large size, even if the origin detection means consisting of the same sliding contact as before is adopted,
The size and cost of the motor can be reduced.

Further, in the case of the present invention, since the motor origin detecting means is used only for driving the electromagnetic relay, FET or booster circuit, the number of lines to be connected to the motor origin detecting means is reduced from two to one in the prior art. This has the advantage that the total number of wires connected to the wiper motor can be reduced from four to three in the end. This also makes it possible to further reduce the size of the motor and improve its productivity and assembly workability. It is possible to improve and further reduce the cost.

In the wiper driving device according to the second aspect, the other end of the exciting coil of the electromagnetic relay is connected to the ground by an operation of turning on the operation switch or a non-detecting operation of the motor origin detecting means, whereby a current is supplied to the exciting coil. Then, the electromagnetic relay is activated, and a current flows to the wiper motor via the normally open terminal and the common terminal of the electromagnetic relay, so that the wiper is driven. In the stopped state (the operation switch is off and the origin is detected), the other end of the motor coil is also connected to the ground via the normally closed terminal and the common terminal of the electromagnetic relay.

For this reason, the wiper is started by the operation of turning on the operation switch, and even if the operation switch is turned off in the home position non-detection state, the operation of the wiper is continued by the operation of the motor home position detection means and the electromagnetic relay, When the home position is detected, the motor current is cut off, the wiper is regeneratively braked, and the wiper is stopped.

At this time, the motor current always flows through the normally open terminal and the common terminal of the electromagnetic relay, and only a small current for driving the electromagnetic relay flows through the motor origin detecting means. Therefore, according to the wiper driving device of the present invention, it is necessary to adopt a conductive material that can withstand a large current as a material of the motor origin detecting means, to make the current path thicker, and to reduce the contact pressure and the amount of deflection of the contact. Since it is not necessary to secure a large size, it is possible to reduce the size and cost of the motor even if the original point detecting means including the sliding contacts as in the related art is employed.

Further, in the case of the present invention, the motor origin detecting means is used only for connecting the exciting coil of the electromagnetic relay to the ground, so that the number of lines to be connected to the motor origin detecting means is reduced from two to one. This has the advantage that the total number of wires connected to the wiper motor can be reduced from four to three in the end. This also makes it possible to further reduce the size of the motor and improve its productivity and assembly workability. Improvement,
Further, the cost can be reduced.

In the wiper driving device according to the third aspect, P
The gate terminal voltages of the channel FET and the N-channel FET are set to the ground level by the ON operation of the operation switch or the non-detection operation of the motor origin detecting means, whereby the wiper motor is connected to the power supply via the P-channel FET and operates. In the stop state (the operation switch is off and the origin is detected), the other end of the motor coil is also connected to ground via the N-channel FET.

For this reason, the wiper is started by the operation of turning on the operation switch, and the operation of the wiper is continued by the operation of the motor origin detection means and the P-channel FET even if the operation switch is turned off in the state where the origin is not detected. ,
When the home position is detected, the motor current is cut off, the wiper is regeneratively braked, and the wiper is stopped.

Therefore, according to the wiper driving device of the present invention, only a small current for driving the FET flows through the motor origin detecting means, though the wiper can be operated in the conventional manner. For this reason, the same effect as the second aspect of the invention can be obtained. Moreover, according to the present invention, since the circuit is switched by the switching operation of the FET, an inherent effect that the sound such as the relay operation sound of the electromagnetic relay is not generated and the operation is quiet is obtained.

The operation of removing an unpleasant sound by using such an FET is particularly effective in a mode in which intermittent driving is performed. That is, when an electromagnetic relay is used in an intermittent drive mode, a relay operation sound is generated every time the wiper intermittently operates.However, if an FET is used instead of the electromagnetic relay, such an unpleasant sound is generated. Because it is completely gone.

In the wiper driving device according to the fourth aspect, the boosting circuit is driven by the ON operation of the operation switch or the non-detection operation of the motor origin detecting means to be in a boosted state, and the gate terminal voltage of the N-channel FET is grounded. Level. As a result, the other end of the motor coil of the wiper motor is disconnected from the ground side, the output of the booster circuit is applied to the other end of the motor coil, and power is supplied to the wiper motor. In the stop state (the operation switch is off and the origin is detected), the other end of the motor coil is also connected to ground via the N-channel FET.

Therefore, even if the wiper is started by the operation of turning on the operation switch and the operation switch is turned off in the state where the origin is not detected, the operation of the wiper is continued by the operation of the motor origin detecting means and the booster circuit. When the home position is detected, the motor current is cut off, the wiper is regeneratively braked, and the wiper is stopped.

Therefore, according to the wiper driving device of the present invention, although the conventional wiper operation is possible, the motor origin detecting means is provided with a booster circuit or an FE.
Only a small current for driving T flows. For this reason, the same effects as those of the second and third aspects can be obtained.

Further, according to the wiper driving device of the fifth aspect, a non-contact type sensor is provided as the motor origin detecting means. This simplifies the waterproof structure and eliminates the need to fill grease. In addition, there is no need to finely set the contact pressure and the amount of deflection of the contact as in the case of using sliding contacts. In this regard, the motor can be further reduced in size, and its productivity and assembly workability can be improved. It is possible to improve and further reduce the cost.

[Brief description of the drawings]

FIG. 1 is a circuit diagram illustrating a wiper driving device according to a first example.

FIG. 2 is a diagram illustrating the operation of the device.

FIG. 3 is a diagram illustrating the operation of the device.

FIG. 4 is a circuit diagram showing a wiper driving device according to a second example.

FIG. 5 is a diagram illustrating the operation of the device.

FIG. 6 is a diagram illustrating the operation of the device.

FIG. 7 is a circuit diagram illustrating a wiper driving device according to a third example.

FIG. 8 is a circuit diagram showing a conventional wiper driving device.

FIG. 9 is a diagram illustrating a relationship between an operation state of an origin detecting unit and a position of a wiper blade.

FIG. 10 is a diagram illustrating the operation of a conventional wiper driving device.

FIG. 11 is a diagram illustrating the operation of a conventional wiper driving device.

FIG. 12 is a circuit diagram showing another example of the conventional wiper driving device.

[Explanation of symbols]

 1, 41 wiper switch (operation switch) 2 wiper motor 21 electromagnetic relay 21a excitation coil 22 motor origin detection switch (motor origin detection means) 31 P-channel FET 32 N-channel FET

Claims (5)

[Claims] An operation switch for instructing an operation of a wiper includes a motor origin detecting means for detecting that a wiper motor is at an origin position, and an operation switch for instructing operation of the wiper. A wiper motor connected to a power supply to drive the wiper in response to the power supply, the power supply to the wiper motor being controlled by an electromagnetic relay, an FET,
A wiper drive, wherein the electromagnetic relay, the FET, or the booster circuit is driven by an ON operation of the operation switch or a non-detection operation of the motor origin detecting means. apparatus. 2. An apparatus according to claim 1, further comprising: motor origin detecting means for detecting that the wiper motor is at the origin position; and an operation switch for instructing operation of the wiper. A wiper driving device for driving the wiper by connecting the wiper motor to a power supply in response to the electromagnetic relay having a common terminal, a normally open terminal, and a normally closed terminal; connecting one end of a motor coil of the wiper motor to a ground; The other end of the motor coil of the wiper motor is connected to a common terminal of the electromagnetic relay, a normally open terminal of the electromagnetic relay is connected to a power source, a normally closed terminal of the electromagnetic relay is connected to ground, One end of the exciting coil is connected to a power source, and the electromagnetic relay The other end of the exciting coil is connected to the ground by the ON operation of the operation switch or the non-detection operation of the motor origin detection means. 3. A motor origin detecting means for detecting that the wiper motor is at an origin position, and an operation switch for instructing operation of the wiper, wherein the operation switch or the motor origin detecting means is operated. A wiper driving device for driving the wiper by connecting the wiper motor to a power supply, wherein a P-channel FET and an N-channel FET are provided; one end of a motor coil of the wiper motor is connected to ground; The other end
The P-channel FET is connected to a power supply via the P-channel FET, and is connected to the ground via the N-channel FET. The gate terminal voltages of the P-channel FET and the N-channel FET are determined by the on-operation of the operation switch or the motor origin. A wiper driving device characterized in that it is configured to be set to a ground level by a non-detection operation of a detection means. 4. An apparatus according to claim 1, further comprising: motor origin detecting means for detecting that the wiper motor is at the origin position; and an operation switch for instructing operation of the wiper. A wiper driving device for driving the wiper by connecting the wiper motor to a power supply according to the present invention, comprising: a booster circuit and an N-channel FET; connecting one end of a motor coil of the wiper motor to ground; The end,
The booster circuit is connected to a power supply via the booster circuit, and connected to ground via the N-channel FET, and the booster circuit is driven by an ON operation of the operation switch or a non-detection operation of the motor origin detecting means. The wiper driving device is configured to be in a boosted state, and the gate terminal voltage of the N-channel FET is set to the ground level by the operation of turning on the operation switch or the non-detection operation of the motor origin detection means. 5. The wiper driving device according to claim 1, further comprising a non-contact type sensor as said motor origin detecting means.