JP2012171417A - Wiper motor control circuit for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiper motor control circuit for an automobile, improving silence in the automobile, while reducing discomfort caused by operation noise of a relay part.SOLUTION: During intermittent operation of a wiper, a wiper start-up signal output part 16 turns on a wiper start-up relay 11 (bc connection) by supplying power to a wiper start-up relay driving part 13. Thus, a wiper motor 21 starts rotation, and a synchronously operating motor switch 22 is turned on (bc connection). An electric current detecting part 15 detects a reversal position where reciprocating operation of a window wiper is changed, on the basis of a characteristic change appearing in a driving current of the wiper motor 21. A wiper start-up signal control part 17 instructs a wiper start-up signal output part 16 to cut off power to the wiper start-up relay driving part 13 based on the detected characteristic change. The wiper start-up signal output part 16 turns off the wiper start-up relay 11 (ac connection) by cutting of power to the wiper start-up relay driving part 13 in response to the instruction.

Description

  The present invention relates to an automotive wiper motor control circuit that controls a wiper motor that reciprocates a window wiper of an automobile, and more specifically, achieves optimization of switching control of a relay for wiper operation during intermittent operation of the window wiper. Related to the wiper motor control circuit.

  As is well known, a wiper system is mounted on an automobile in order to wipe off raindrops and the like adhering to the window glass of the automobile. This wiper system basically connects a wiper motor that generates a rotational motion, a control device that controls the rotation of the wiper motor, a window wiper (wiper blade) that reciprocates on the surface of a window glass, and a wiper motor and a window wiper. At the same time, a link mechanism that converts the rotational operation of the wiper motor into the reciprocating operation of the window wiper is configured. With this configuration, the wiper motor is appropriately rotated, and raindrops and the like attached to the window glass are wiped off by the window wiper.

In general, a relay component is used for rotation control of the wiper motor, and the following control is performed when the window wiper is operated intermittently.
According to the wiper operation instruction received from the driver, the relay part is first turned on, and power is supplied to the wiper motor via the relay part. The wiper motor supplied with the power starts rotating. The wiper motor is provided with a switch unit that is turned on or off in synchronization with the rotation of the wiper motor. The wiper motor is turned on after the wiper motor starts rotating. The power can be supplied. When a predetermined time elapses after the switch part is turned on, the relay part is turned off, and the power supply to the wiper motor is switched from the supply via the relay part to the supply via the switch part. Even after the power supply to the wiper motor is switched to supply via the switch unit, the wiper motor continues to rotate. When a predetermined amount of rotation operation ends, the power supply by the switch unit stops and the wiper motor also stops.
Thus, the reciprocating motion on the window glass by the window wiper is executed by the cooperative control of the power supply by the relay component and the switch unit.

  Usually, the relay component used for rotation control of the wiper motor is an electromagnetic switch that mechanically switches contacts, and a slight operating noise is generated when switching between the on state and the off state. If the relay parts are installed in a place sufficiently away from the passenger or a place where the noise is erased, the operation sound is not anxious. However, due to functional integration in recent automobiles, the number of cases in which relay components are built in the wiper operation switch is increasing. That is, in a quiet vehicle, the relay component is operated at a position close to the driver.

  Here, when the relay part is turned on, that is, when the supply of power to the wiper motor is started, there is a change in the operation state that the window wiper starts to move in response to the operation sound of the relay part. It is not considered. However, when the relay part is turned off, that is, when the power supply to the wiper motor is switched from the relay part to the switch part, the wiping action by the window wiper is in progress, and the operation state of the window wiper with respect to the operation sound of the relay part Does not change at all. For this reason, the operation sound of the relay component generated when the movement of the window wiper does not change is regarded as abnormal noise, and the driver may feel uncomfortable. Such a sense of incongruity is a problem that causes a loss of comfort in a quiet vehicle.

  As a technique for solving this problem, for example, there is a technique proposed in Patent Document 1. In the technique described in Patent Document 1, from the viewpoint that the time required for the window wiper to travel in the forward direction is substantially equal to the time required for the return path operation, the reciprocating operation time actually performed by the window wiper is measured. Find half the operating time. Then, the relay part is switched from the on state to the off state at the timing when the obtained half time has elapsed after the window wiper is activated.

  With this control, in Patent Document 1, the operation sound of the relay component is generated by generating the operation sound when the relay component is turned off in accordance with the timing at which the window wiper finishes the forward operation and temporarily stops at the reverse position. In contrast, the driver feels uncomfortable with a change in the operating state of the window wiper.

JP 2009-143305 A

  However, in the control described in the above-mentioned conventional patent document 1, based on the reciprocating operation time actually performed by the window wiper last time, the time for the window wiper to reverse from the forward operation to the backward operation is obtained, and this obtained time is calculated. This is used as the switching timing of the relay component from the on state to the off state in the window wiper operation performed this time.

  For this reason, immediately after the window wiper operating speed changes, such as when the intermittent time is adjusted by the driver, or when the precipitation changes due to the raindrop detection function, the window wiper reverses from the forward operation to the return operation. There is a problem that the position at which the relay component is switched and the timing at which the relay component is switched from the on state to the off state are shifted, and the uncomfortable feeling experienced by the driver of the automobile cannot be sufficiently mitigated.

  Therefore, the object of the present invention is not to obtain the time for the window wiper to reverse from the forward operation to the return operation from the reciprocation time that the window wiper actually performed last time, but the window wiper is inverted from the forward operation to the return operation. Wiper motor control for automobiles that can improve the quietness in the automobile by switching the relay parts to the OFF state by directly detecting the timing and scraping the operation noise of the relay parts with the friction sound between the shield glass and wiper blade rubber To provide a circuit.

  The present invention is directed to an automotive wiper motor control circuit that controls a wiper motor that reciprocates a window wiper. In order to achieve the above object, an automotive wiper motor control circuit according to the present invention is a wiper that switches between an on state in which a wiper motor is activated by applying power and an off state in which no power is applied to the wiper motor in accordance with a wiper activation signal. If the wiper start relay is turned off between the start of the start relay and the wiper motor when the wiper start relay is turned on until the window wiper completes one reciprocating motion, the wiper start relay is replaced with the wiper motor. A wiper motor switch that continuously applies power, a drive current of the wiper motor is measured, a current detection unit that detects a timing at which the window wiper reverses from a forward operation to a backward operation, and a timing detected by the current detection unit, or Tie a certain time before or after the timing In ring, wiper activation relay to switch off, and a wiper activation signal control means for controlling the wiper activation signal.

  According to the present invention, since the characteristic change of the drive current flowing through the wiper motor that occurs when the window wiper is switched from the forward operation to the return operation is detected and the inversion timing of the window wiper is determined, the operation speed of the window wiper is Even immediately after the change, the window wiper inversion timing does not deviate from the timing at which the wiper activation relay is switched from the on state to the off state. As a result, the wiper activation relay can be reliably switched to the OFF state at an appropriate timing, so that the driver can feel uncomfortable and improve the quietness of the vehicle.

The figure which shows the structure of the wiper motor control circuit 1 for motor vehicles based on the 1st Embodiment of this invention. The figure which showed notionally the waveform of the drive current which flows into wiper motor 21 at the time of rotation operation Timing chart showing relationship between states and signals in each configuration of wiper motor control circuit 1 for automobile The figure which shows the structure of the wiper motor control circuit 2 for motor vehicles based on the 2nd Embodiment of this invention. The timing chart which showed the relationship of the state and signal in each structure of the wiper motor control circuit 2 for motor vehicles shown in FIG. The figure which shows the structure of the wiper motor control circuit 3 for motor vehicles based on the 3rd Embodiment of this invention. Timing chart showing the relationship between states and signals in each configuration of the automotive wiper motor control circuit 3 shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
FIG. 1 is a diagram showing a configuration of an automotive wiper motor control circuit 1 according to a first embodiment of the present invention. In FIG. 1, an automotive wiper motor control circuit 1 according to a first embodiment includes a wiper motor control unit 10 and a wiper motor unit 20. The wiper motor control unit 10 includes a wiper activation relay 11, a wiper speed switching relay 12, a wiper activation relay driving unit 13, a wiper speed switching relay driving unit 14, a current detection unit 15, and a wiper activation signal output unit 16. And a wiper activation signal control unit 17. The wiper motor unit 20 includes a wiper motor 21 and a motor switch 22.

First, the outline | summary of each structure mentioned above in the wiper motor control circuit 1 for motor vehicles based on 1st Embodiment is demonstrated.
The wiper activation signal output unit 16 generates a wiper activation signal corresponding to the window wiper operation instructed by the driver, and outputs the wiper activation signal to the wiper activation relay drive unit 13 and the wiper speed switching relay drive unit 14. Specifically, when a continuous operation, intermittent operation, and mist operation of the window wiper (operation linked to the injection of the window washer fluid) is instructed, the high-level wiper activation signal is not instructed about the operation of the window wiper. For example, a low level wiper activation signal is output from the wiper activation signal output unit 16 to the wiper activation relay drive unit 13. In addition, when there is no instruction regarding the operation of the window wiper, the wiper activation signal may not be output (no signal). Further, regarding the continuous operation of the window wiper, a wiper activation signal of a high level or a low level according to an instruction of a high speed (Hi) or a low speed (Lo) is driven from the wiper activation signal output unit 16 to drive the wiper speed switching relay. Is output to the unit 14.

The wiper activation relay drive unit 13 includes, for example, a switching transistor, and controls the conduction and non-conduction of the transistor according to the wiper activation signal supplied from the wiper activation signal output unit 16 to thereby turn on and off the device itself. Switch. Specifically, when the wiper activation signal is high, the wiper activation relay drive unit 13 is turned on and the transistor is turned on, and when the wiper activation signal is low, the transistor is turned off and turned off. .
Similarly, the wiper speed switching relay drive unit 14 includes, for example, a switching transistor, and controls the conduction and non-conduction of the transistor in accordance with the wiper activation signal supplied from the wiper activation signal output unit 16 to thereby turn on the wiper speed switching relay drive unit 14. Switch between state and off state. Specifically, the wiper speed switching relay drive unit 14 is turned on when the wiper activation signal is at a high level, and is turned off when the wiper activation signal is at a low level. .

The wiper activation relay 11 is an electromagnetic switch composed of a coil and a movable contact. One end of the coil and the terminal b are connected to the IG power source (ignition power source), and the other end of the coil is connected to the wiper activation relay drive unit 13. a is connected to the motor switch 22, and the terminal c is connected to the current detector 15. When the wiper activation relay drive unit 13 is in an OFF state (transistor is non-conductive), the wiper activation relay 11 connects the terminal a and the terminal c without current flowing through the coil, and the wiper activation relay drive unit 13 In the on state (transistor is conductive), a current flows through the coil and is excited to connect the terminal b and the terminal c.
The wiper speed switching relay 12 is also an electromagnetic switch composed of a coil and a movable contact. One end of the coil is an IG power source, the other end of the coil is a wiper speed switching relay drive unit 14, and a terminal a is a wiper motor. The terminal b is connected to the high speed side of the wiper motor 21, and the terminal c is connected to the current detection unit 15. When the wiper speed switching relay drive unit 14 is in an off state (transistor is non-conductive), the wiper speed switching relay 12 connects the terminal a and the terminal c without flowing current through the coil, and drives the wiper speed switching relay. When the unit 14 is in an on state (transistor is conductive), a current flows through the coil and is excited to connect the terminal b and the terminal c.

The wiper motor 21 generates a rotation operation by an IG power source supplied via the wiper activation relay 11 and the wiper speed switching relay 12, and the generated rotation operation is window wiper via a predetermined link mechanism (not shown). It is converted to reciprocating motion and transmitted.
The motor switch 22 is a rotary sliding switch that is turned on or off in conjunction with and synchronized with the rotation of the wiper motor 21. Specifically, when the wiper motor 21 is stopped, the terminal a and the terminal c are connected to be in the grounded state (GND connection), and until the wiper motor 21 starts rotating and stops, Terminal b and terminal c are connected and an IG power supply is applied.

The current detection unit 15 is connected between the wiper activation relay 11 and the wiper speed switching relay 12. The current detection unit 15 observes the drive current flowing through the wiper motor 21 during the rotation operation, and detects a characteristic change that appears in the drive current of the wiper motor 21. This characteristic change will be described later. The detection result of this characteristic change is notified to the wiper activation signal control unit 17.
When the wiper activation signal control unit 17 is notified from the current detection unit 15 that a characteristic change in the drive current of the wiper motor 21 has been detected, the wiper activation signal control unit 17 determines that the timing at which the window wiper is reversed from the forward operation to the return operation is detected. To do. Then, according to this determination, the wiper activation signal control unit 17 instructs the wiper activation signal output unit 16 to change the wiper activation signal to a low level. The wiper activation signal output unit 16 changes the wiper activation signal output to the wiper activation relay 11 to a low level based on an instruction from the wiper activation signal control unit 17 (or stops outputting the wiper activation signal). .

Next, the wiper motor control performed by the automotive wiper motor control circuit 1 according to the first embodiment will be described in detail with further reference to FIGS.
FIG. 2 is a diagram conceptually showing the waveform of the drive current flowing through the wiper motor 21 during the rotation operation. FIG. 3 is a timing chart showing the relationship between the states and signals in each configuration of the automotive wiper motor control circuit 1.

  First, referring to FIG. 2, the operation from when the window wiper reaches the reversal position from the initial position (forward path) and then returns to the initial position from the reversal position (return path), and the drive current flowing through the wiper motor 21 The relationship will be described.

  When the window wiper starts the forward movement from the initial position, the drive current that has been zero increases to a steady value at a stretch (period A). During the forward operation, the friction between the shield glass and the wiper blade rubber is substantially constant, and thus a steady-state driving current continues to flow (period B). After that, when the window wiper reaches the reverse position, the wiper blade stops instantaneously, so that the load on the wiper motor 21 is temporarily reduced, and the drive current is temporarily reduced from the steady value (period C). Next, when the return path operation starts from the reverse position, the window wiper must move from the stopped state, so the friction between the shield glass and the wiper blade rubber increases momentarily, and the drive current temporarily increases from the steady value (period). D). Thereafter, during the return path operation, the friction between the shield glass and the wiper blade rubber is substantially constant, and thus a steady-state drive current continues to flow (period E). Then, when the window wiper returns to the initial position, the drive current in which the steady value has flowed decreases to zero (period F).

As described above, the drive current flowing through the wiper motor 21 exhibits characteristic changes indicated by the period C and the period D in FIG. 2 before and after the inversion position where the window wiper operation is switched from the forward operation to the return operation.
The present invention pays attention to the characteristic change of the drive current flowing through the wiper motor 21 and detects the change in which the drive current starts to rise after falling from the steady value, so that the operation of the window wiper is changed from the forward operation to the return operation. The reversal timing at which the wiper activation relay 11 is switched to is determined and used for off-state control of the wiper activation relay 11.

  Hereinafter, the procedure in which the wiper motor control circuit 1 for an automobile according to the present invention controls the wiper activation relay 11 to the OFF state in order to obtain the reversal timing at which the window wiper operation is switched from the forward operation to the return operation will be described with reference to FIG. To do.

  The wiper activation signal output unit 16 outputs a high level wiper activation signal in response to an instruction to intermittently operate the window wiper given by the driver (state [1]). By this high level wiper activation signal, the wiper activation relay drive unit 13 is turned on and the wiper activation relay 11 is turned on (state [2]). The wiper activation relay 11 that has been turned on connects the terminal c to the terminal b, and supplies the IG power applied to the terminal b to the wiper motor 21 via the current detection unit 15 and the wiper speed switching relay 12. . Note that whether the wiper speed switching relay 12 is in the on state or the off state does not directly affect the present invention, and thus the description thereof will be omitted. Regardless of the state of the wiper speed switching relay 12, the IG power is supplied to the wiper motor 21 (either the high speed terminal or the low speed terminal).

  The wiper motor 21 is in a rotation stop state until the IG power is supplied (state [3]), and the drive current detected by the current detector 15 is also zero (state [4]). In this case, the motor switch 22 is in an off state (GND connection) in synchronization with the rotation of the wiper motor 21 (state [5]). When IG power is supplied from the wiper activation relay 11, the wiper motor 21 starts rotating (state [6]), and the current detection unit 15 detects a steady-state drive current (state [7]). . Thereafter, when the wiper motor 21 rotates a predetermined angle, the motor switch 22 is switched to the ON state (state [8]). By switching to the ON state, the terminal c of the motor switch 22 is connected to the terminal b, and the IG power applied to the terminal b is connected to the terminal a of the wiper activation relay 11.

  When the window wiper reaches the reverse position after continuing the forward movement operation (state [9]), the driving current of the wiper motor 21 detected by the current detector 15 shows the characteristic change described above (state [10]). . The wiper activation signal controller 17 detects the inversion of the window wiper based on the characteristic change detected by the current detector 15 and outputs a control signal for changing the wiper activation signal to a low level. 16 (state [11]). The wiper activation signal output unit 16 changes the wiper activation signal to a low level according to the control signal (state [12]). In response to the change in the wiper activation signal, the wiper activation relay 11 is switched off (state [13]). By switching to the OFF state, the terminal c of the wiper activation relay 11 is connected to the terminal a.

Thereafter, the wiper motor 21 continues to rotate by receiving supply of IG power from the wiper activation relay 11 via the motor switch 22, and rotates at a steady-state drive current until the window wiper finishes the return path operation and returns to the initial position. . When the window wiper returns to the initial position, the motor switch 22 operating in synchronism is turned off, the supply of IG power is stopped (state [14]), and the wiper motor 21 stops rotating (state [ 15]).
Thereafter, the window wiper intermittent operation is realized by repeating the above-described state [1] to state [15] at intervals of a preset intermittent time.

  As described above, the automotive wiper motor control circuit 1 according to the first embodiment of the present invention detects a characteristic change in the drive current flowing in the wiper motor 21 that occurs when the window wiper switches from the forward operation to the return operation. Then, the inversion timing of the window wiper is determined. Therefore, even immediately after the operation speed of the window wiper changes, the window wiper inversion timing does not deviate from the timing at which the wiper activation relay 11 is switched from the on state to the off state. Accordingly, the operation sound generated when the wiper activation relay 11 is switched to the OFF state can be reliably generated at the timing when the window wiper is about to start the return path operation from the reverse position. The frictional noise between the shield glass and the wiper blade rubber is used to eliminate the uncomfortable feeling to the driver and improve the quietness of the vehicle.

<Second Embodiment>
FIG. 4 is a diagram showing the configuration of the automotive wiper motor control circuit 2 according to the second embodiment of the present invention. In FIG. 4, the automotive wiper motor control circuit 2 according to the second embodiment has a configuration in which the automotive wiper motor control circuit 1 according to the first embodiment described above further includes a control adjustment unit 18. Since the configuration other than the control adjustment unit 18 in the automotive wiper motor control circuit 2 is the same as the configuration of the automotive wiper motor control circuit 1, the same reference numerals are used and a part of the description is omitted.

  As described in the first embodiment, the characteristic change detected by the current detection unit 15 indicates the reversal timing at which the window wiper switches from the forward operation to the return operation, but actually the shield glass There is also a case where the friction noise between the wiper blade rubber and the wiper blade rubber is generated later than the reversal timing. In such a case, it is desired to delay the timing for canceling the operation sound of the wiper activation relay 11 from this inversion timing. Therefore, the automotive wiper motor control circuit 2 performs the following control using the control adjustment unit 18.

  The current detection unit 15 detects a characteristic change in the drive current of the wiper motor 21 and notifies the control adjustment unit 18 of the detection result. When the control adjustment unit 18 is notified from the current detection unit 15 that a characteristic change in the drive current of the wiper motor 21 has been detected, the control adjustment unit 18 waits for the elapse of a predetermined time from the time of the notification and sends the same notification to the wiper activation signal. Output to the control unit 17. This predetermined time is set in advance in the control adjustment unit 18, and the control adjustment unit 18 determines the elapse of the predetermined time by counting the predetermined time using, for example, a counter. When the wiper activation signal control unit 17 receives a notification indicating that a characteristic change in the drive current of the wiper motor 21 has been detected from the control adjustment unit 18, the wiper activation signal control unit 17 generates a control signal for changing the wiper activation signal to a low level. Output to the wiper activation signal output unit 16.

  By the delay control of the predetermined time by the control adjusting unit 18, the timing at which the wiper activation relay 11 is switched to the off state can be delayed as shown in FIG. FIG. 5 is a timing chart showing the relationship between the states and signals in each configuration of the automotive wiper motor control circuit 2.

  As described above, according to the automobile wiper motor control circuit 2 according to the second embodiment of the present invention, the timing for switching the wiper activation relay 11 from the on state to the off state can be delayed by an arbitrary time. As a result, the operation sound of the wiper activation relay 11 that could not be erased by the configuration of the first embodiment can also be erased by the configuration of the second embodiment, and the driver can feel uncomfortable. The quietness of the vehicle can be improved.

<Third Embodiment>
FIG. 6 is a diagram showing a configuration of an automotive wiper motor control circuit 3 according to the third embodiment of the present invention. In FIG. 6, the automotive wiper motor control circuit 3 according to the third embodiment has a configuration in which the automotive wiper motor control circuit 1 according to the first embodiment described above further includes a control adjustment unit 19. Since the configuration other than the control adjustment unit 19 in the automotive wiper motor control circuit 3 is the same as the configuration of the automotive wiper motor control circuit 1, the same reference numerals are given and a part of the description is omitted.

  As described in the first embodiment, the characteristic change detected by the current detection unit 15 indicates the reversal timing at which the window wiper switches from the forward operation to the return operation, but actually the shield glass In some cases, the frictional noise between the wiper blade rubber and the wiper blade rubber is generated earlier than the reversal timing. In such a case, it is desired to advance the timing for canceling the operation sound of the wiper activation relay 11 from this inversion timing. Therefore, the automotive wiper motor control circuit 3 performs the following control using the control adjustment unit 19.

  The wiper activation signal output unit 16 also outputs a wiper activation signal output to the wiper activation relay drive unit 13 to the control adjustment unit 19. The current detection unit 15 detects a characteristic change in the drive current of the wiper motor 21 and notifies the control adjustment unit 19 of the detection result. Based on the wiper activation signal output from the wiper activation signal output unit 16 and the detection result of the current detection unit 15, the control adjustment unit 19 changes the wiper activation signal to high level, that is, the wiper activation relay 11 The operation time from when the ON state is switched to when the current detection unit 15 detects a characteristic change in the drive current of the wiper motor 21 is measured and stored. Then, when the wiper activation relay 11 is next switched on, the control adjustment unit 19 causes the current detection unit 15 to adjust the drive current of the wiper motor 21 when a time obtained by subtracting a predetermined time from the stored operation time has elapsed. A dummy notification indicating that a characteristic change has been detected is output to the wiper activation signal control unit 17. This predetermined time is set in advance in the control adjustment unit 19, and the control adjustment unit 19 counts a predetermined time from the operation time by counting a time obtained by subtracting the predetermined time from the operation time stored using, for example, a counter. Determine the passage of time going back in time. When the wiper activation signal control unit 17 receives a dummy notification indicating that a characteristic change in the drive current of the wiper motor 21 is detected from the control adjustment unit 19, the wiper activation signal control unit 17 changes the wiper activation signal to a low level. Is output to the wiper activation signal output unit 16.

  By the retroactive control for a predetermined time by the control adjusting unit 19, the timing at which the wiper activation relay 11 is switched to the OFF state can be advanced as shown in FIG. FIG. 7 is a timing chart showing a relationship between states and signals in each configuration of the automotive wiper motor control circuit 3.

  As described above, according to the automotive wiper motor control circuit 3 of the third embodiment of the present invention, the timing for switching the wiper activation relay 11 from the on state to the off state can be advanced by an arbitrary time. As a result, the operation sound of the wiper activation relay 11 that could not be erased by the configuration of the first embodiment can also be erased by the configuration of the third embodiment, and the discomfort to the driver can be alleviated. The quietness of the vehicle can be improved.

  In the third embodiment, the current detection unit 15 is connected to the wiper motor 21 after the wiper activation signal stored in the control adjustment unit 19 changes to a high level, that is, after the wiper activation relay 11 is turned on. The case where the operation time until the characteristic change of the drive current is detected is only for the last time has been described. However, the control adjusting unit 19 may store past operation times for a plurality of times, and use the average value of the plurality of operation times as a work time to be subtracted from the predetermined time.

  INDUSTRIAL APPLICABILITY The present invention can be used for an automobile equipped with a wiper motor control circuit capable of intermittent operation of a window wiper, and particularly reduces an uncomfortable feeling caused by an operation sound of a wiper activation relay, thereby improving quietness in the automobile. This is useful when you want to make it happen.

1, 2, 3 Car wiper motor control circuit 10 Wiper motor control unit 11 Wiper activation relay 12 Wiper speed switching relay 13 Wiper activation relay driving unit 14 Wiper speed switching relay driving unit 15 Current detection unit 16 Wiper activation signal output unit 17 Wiper activation signal Control units 18, 19 Control adjustment unit 20 Wiper motor unit 21 Wiper motor 22 Motor switch

Claims (1)

An automotive wiper motor control circuit for controlling a wiper motor that reciprocates a window wiper,
A wiper activation relay that switches between an on state in which power is applied to activate the wiper motor and an off state in which no power is applied to the wiper motor in accordance with a wiper activation signal;
If the wiper activation relay is switched off after the wiper motor is activated by the on state of the wiper activation relay until the window wiper completes one reciprocating operation, the wiper activation relay is replaced with the wiper activation relay. A wiper motor switch for continuously applying power to the wiper motor;
A current detection means for measuring a driving current of the wiper motor and detecting a timing at which the window wiper reverses from a forward operation to a backward operation;
A wiper activation signal control for controlling the wiper activation signal so that the wiper activation relay is switched off at the timing detected by the current detection means, or at a timing before or after a predetermined time from the timing. And a wiper motor control circuit for an automobile.

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