JP5563815B2 - Motor device and wiper device including the motor device - Google Patents

Description

  The present invention relates to a motor device that drives a worm wheel speed reducer, and more particularly to a motor device used in a vehicle wiper device such as an automobile, and a wiper device including the motor device.

  As a drive source of a vehicle wiper device such as an automobile, a motor device using an electric motor (simply referred to as “motor”) that is operated by a power source such as a battery mounted on the vehicle is used. In such a motor device, a speed reduction mechanism for reducing the rotational speed of the output shaft of the motor to a required rotational speed is attached, and the motor device with the speed reduction mechanism is a single unit. This motor device is used as the wiper device, and the wiper arm swings between the upper reverse position and the lower reverse position using this motor device as a drive source.

  As a prior art related to this wiper device, a wiper device control method, a wiper device, and a motor with a speed reduction mechanism have been disclosed (see Patent Document 1). In this wiper device, a wiper wiping angle detection structure using two hall elements is disclosed. Moreover, the related wiper apparatus control method is disclosed (refer patent document 2). This wiper device control method discloses a wiper device control method in which the position of the wiper arm is detected by a single sensor.

  In the wiper device that performs forward / reverse rotation control of the wiper disclosed in Patent Document 1 and Patent Document 2, an annular ring magnet (magnet) is attached to a worm wheel, and a Hall IC is assembled so as to face the ring magnet. It has been found. In this case, as shown in Patent Document 2, when one Hall IC (an IC in which a Hall element and a detection circuit are integrated to form a module) is used, the resolution is insufficient with respect to the rotation of the wiper, or when the motor is started, There are problems such as difficulty in position detection. For this reason, as shown in Patent Document 1, two Hall ICs are arranged facing the ring magnet on the worm wheel.

Here, a configuration example of a wiper device in which two Hall ICs are arranged facing the ring magnet of the worm wheel will be described.
FIG. 10 is a diagram for explaining the wiper device. The wiper device shown in FIG. 10 is a device that swings and drives the wiper arm 202 in the wiper unit 201 by the motor unit 101. The motor unit 101 includes a motor 111 and a speed reduction mechanism including a worm 112 and a worm wheel (drive gear) 121. A wiper blade 203 is attached to the distal end portion of the wiper arm 202 of the wiper portion 201, and the wiper arm 202 is attached to the wiper shaft 122 of the worm wheel 121 at the base end portion. That is, when the motor 111 rotates forward and backward, the worm wheel 121 rotates forward and backward, and the wiper arm 202 attached to the wiper shaft 122 reciprocates left and right in the drawing. For example, the wiper arm 202 and the wiper blade 203 reciprocate between the lower inversion position A and the upper inversion position B (reversing wiper).

  Further, a C-phase sensor 124 and a D-phase sensor 125, which are Hall ICs for absolute position detection, are arranged at positions facing the side surface side of the worm wheel 121. As the C-phase sensor 124 and the D-phase sensor 125, sensors capable of determining the type of magnetic pole (N pole or S pole) together with the change of the magnetic pole are used. Further, a ring magnet 123 is attached to the side surface of the worm wheel 121 as a member to be detected (a detection target) of the C-phase sensor 124 and the D-phase sensor 125 for detecting the absolute position. The ring magnet 123 rotates integrally with the worm wheel 121 and is magnetized to two poles (for example, 90 degrees N pole and 270 degrees S pole) in the rotation direction.

  The rotating shaft 111a of the motor 111 is connected to the worm 112, and the rotating shaft 111a includes a ring-shaped multipolar magnetized magnet (for example, six poles in the rotating direction) that rotates integrally with the rotating shaft 111a. ) 113 is attached. The A-phase sensor 114 that is a Hall IC and the B-phase sensor 115 that is also a Hall IC are shifted from the rotation direction of the magnet 113 by 45 degrees, for example, at positions facing the magnet 113. It is attached. When the rotating shaft 111a of the motor 111 rotates, the A-phase sensor 114 and the B-phase sensor 115 output pulses for six cycles per one rotation of the rotating shaft 111a. This pulse is transmitted toward a control unit (not shown), and the rotation speed, the rotation direction, and the rotation position of the motor 111 are detected by counting the pulses.

  FIG. 11 is a diagram showing an example of a positional relationship between the worm wheel side sensors (C-phase sensor 124 and D-phase sensor 125) and the ring magnet 123. As shown in FIG. 11, in the ring magnet 123, the magnetization angle of one pole (here, S pole) is larger than that of the other pole (here, N pole). As the worm wheel 121 rotates, the magnetic poles passing in front of the C-phase sensor 124 and the D-phase sensor 125 change accordingly. The position (area) of the wiper arm 202 (worm wheel 121) can be recognized by the combination of the changes.

As shown in FIG. 11A, when the wiper arm 202 is in the retracted position, the S and N poles of the ring magnet 123 face the C phase sensor 124 and the D phase sensor 125, respectively. Accordingly, the C-phase sensor 124 detects the S pole, and the D-phase sensor 125 detects the N pole.
When the wiper shaft 122 rotates and the wiper arm 202 comes to the lower inversion position, the N-pole of the ring magnet 123 also faces the C-phase sensor 124. The C-phase sensor 124 detects the N pole, and the D-phase sensor 125 detects the N pole.
When the wiper shaft 122 further rotates and the wiper arm 202 comes to the origin position, the C-phase sensor 124 moves from the N pole of the ring magnet 123 to the S pole. At this time, the magnetic pole detected by the C phase sensor 124 changes from the N pole to the S pole, and the D phase sensor 125 detects the S pole.
When the wiper arm 202 comes to the upper inversion position, the S pole of the ring magnet 123 faces both the C phase sensor 124 and the D phase sensor 125. As shown in FIG. 11D, the C-phase sensor 124 detects the S pole, and the D-phase sensor 125 detects the S pole.

  FIG. 12 is a diagram illustrating an example of the position detection of the wiper arm 202 using a sensor on the worm wheel side. FIG. 12A shows an example of area transition when there are two sensors (Hall IC) on the worm wheel side (Hall IC) (C phase sensor 124 and D phase sensor 125). FIG. 12B shows an example of area shift when there is one worm wheel side sensor (Hall IC) (only the C-phase sensor 124). In FIG. 12, the horizontal axis indicates the position of the arm, and the vertical axis indicates the output state of the sensor. In the sensor output state, “0 (Low)” indicates a state in which the Hall IC detects the S pole, and “1 (High)” indicates a state in which the Hall IC detects the N pole. ing.

When two Hall ICs are used, as shown in FIG. 12A, when the wiper arm 202 moves from the retracted position to the upper inverted position through the lower inverted position, the C-phase sensor 124 and the D-phase sensor 125 The output state shifts from “Area (1) → Area (2) → Area (3) → Area (4)”.
That is, the output of the C-phase sensor 124 is started from the position P1 which is “area (1)” in which the output of the C-phase sensor 124 is “0” and the output of the D-phase sensor 125 is “1”. Shifts to “Area (2)” where “1” and the output of the D-phase sensor 125 are “1”, the output of the C-phase sensor 124 is “1” and the output of the D-phase sensor 125 is “0” at the position P3. “Area (3)”. Then, after passing through the lower inversion position P4, at the position P5, the process proceeds to “area (4)” where the output of the C-phase sensor 124 is “0” and the output of the D-phase sensor 125 is “0”.

  Conversely, when the wiper arm moves from the upper reversal position to the retracted position via the lower reversal position, the output state of the C-phase and D-phase sensors 125 is “Area (4) → Area (3) → Area (2) → Area ( 1) ".

On the other hand, when one Hall IC (C-phase sensor 124) is used, the output states of the C-phase sensor 124 and the D-phase sensor 125 are as follows when the wiper arm moves from the retracted position to the upper inverted position through the lower inverted position. Then, at the position P2 of the wiper arm, a transition is made from “area (α) → area (β)”.
That is, the “area (α)” where the output of the C-phase sensor 124 is “1” starts from the position P1, and at the position P2, the output of the C-phase sensor 124 becomes “0” from “1”. (Β) ”. Conversely, when the arm moves from the upper reversal position to the storage position via the lower reversal position, the output state of the C-phase sensor 124 shifts from “area (β) → area (α)”.

JP 2004-189197 A JP 2005-104337 A

  As described above, a wiper device that performs forward / reverse rotation control of a wiper arm has an annular ring magnet attached to a worm wheel and a sensor that detects magnetism so as to face the ring magnet. In this case, as shown in FIG. 12A, by using a sensor for detecting magnetism, the combination of the outputs of the sensors for detecting magnetism is associated with the position of the wiper arm in advance to detect magnetism. The position of the wiper arm is determined based on the output of the sensor.

  However, even when two sensors are provided on the worm wheel side, if the sensor fails, the current position (area) of the wiper arm cannot be detected, and the arm may overrun beyond the upper stop position and the lower stop position. is there. For this reason, when a sensor breaks down, it is necessary to stop the sensor before it affects other devices. Therefore, it is necessary to accurately detect the failure of the sensor.

  The present invention has been made in view of such circumstances, and an object of the present invention is to generate a failure in the two sensors when two sensors for detecting the rotational position of the worm wheel (wiper arm) are used. An object of the present invention is to provide a motor device and a wiper device including the motor device.

The motor device according to claim 1 of the present invention that solves the above-described problem is a reduction gear configured by a worm and a worm wheel, a motor that drives the worm of the reduction gear, and a phase that varies according to the rotation of the rotation shaft of the motor. A first sensor and a second sensor that output a pulse signal of the second sensor, and a third sensor and a second sensor that are arranged at different positions along the circumferential direction of the worm wheel with respect to the detection target on the worm wheel. 4 and the first level output state and the second level output state of the third and fourth sensors according to the rotation direction of the worm wheel detected by the first and second sensors. The first reason for detecting the occurrence of a failure in the third and fourth sensors by determining whether or not the order of switching between the two is a predetermined order. A determining unit, characterized in that it comprises said control unit a sensor failure by the first abnormality determination unit operates the said motor in a predetermined failure mode if it is detected.
In this motor device, first and second sensors (A-phase sensor and B-phase sensor) for detecting the rotation of the motor rotation shaft with different phases, and third and fourth sensors (C for detecting the rotational position of the worm wheel). Phase sensor, D phase sensor), and when the worm wheel rotates, the rotational direction of the motor rotation shaft is detected based on the outputs of the first and second sensors, and the third and fourth worm wheel side The switching order of the output states (first level or second level) of the sensors (C phase sensor, D phase sensor) is detected. Then, the occurrence of a failure in the third and fourth sensors (C-phase sensor and D-phase sensor) is detected by determining whether or not the output state is switched according to the detected rotation direction.
Thereby, when detecting the rotation position of a worm wheel using two sensors (C phase sensor, D phase sensor), failure of these two sensors can be detected easily. For this reason, when a failure occurs in the sensor on the worm wheel side, the motor can be controlled in a predetermined failure mode such as stopping the motor before affecting other devices.

Further, makes the chromophore at the distal end over data involved in claim 1 apparatus, according to the combination of the output state in the third and fourth sensor divided into four rotational position of the worm wheel, said first and second Measuring the driving amount of the worm wheel based on the number of pulses output from the sensor, and determining whether the driving amount of the worm wheel in each section exceeds a predetermined number of pulses. A second failure detection unit that detects the occurrence of a failure in the sensor of No. 4, and the control unit further causes the motor to operate in the failure mode when the second failure detection unit determines that a failure has occurred. It is characterized by that.
In this motor device, the rotational position of the worm wheel is further divided into four according to the combination of the output states of the two sensors on the worm wheel side (C-phase sensor, D-phase sensor), and the rotation of the motor rotation shaft is controlled. When the number of pulses output from the sensors to be detected (A phase sensor, B phase sensor) is measured for each section, and the width of the number of pulses in each section exceeds a predetermined number of pulses, It is determined that a failure has occurred in the fourth sensor.
As a result, by using the sensor failure determination based on the detection of the driving amount and the sensor failure determination based on the detection of the switching order, the occurrence of the failure in the worm wheel side sensor (C phase sensor, D phase sensor) can be performed more reliably. The accuracy of detecting can be improved.

Further, the invention according to claim 2 is the motor device according to claim 1 , wherein the first and second sensors detect the forward rotation and the reverse rotation of the worm wheel, respectively. Monitoring the output state of the fourth sensor when the output state of the third sensor is switched and the output state of the third sensor when the output state of the fourth sensor is switched; A third failure determination unit that determines that a failure has occurred in the sensor when the output state of the sensor of 4 does not match the predetermined output state, and the control unit further includes the third failure determination In this motor device, the fourth sensor (D when the output state of the third sensor (C-phase sensor) is switched is operated. Phase sensor) And the output state of the third sensor (C-phase sensor) when the output state of the fourth sensor (D-phase sensor) is switched, and the third and fourth sensors (C-phase sensor, A failure is determined when the output state of the (D-phase sensor) does not match the predetermined output state.
Thus, by combining the failure determination based on the detection of the counterpart sensor level, the sensor failure determination based on the detection of the area order, and the sensor failure determination based on the detection of the area width, the worm wheel can be more reliably used. The accuracy of detecting the occurrence of a failure in the side sensor (C phase sensor, D phase sensor) can be improved.

The invention according to claim 3 is the motor device according to claim 1 or 2 , wherein the third sensor and the fourth sensor are magnetic detection elements, and the worm wheel The upper object to be detected is arranged on the side surface of the worm wheel on a ring, and has a first magnetic pole and a second magnetic pole having different polarities along the circumferential direction, and according to the rotation of the worm wheel A first region in which the magnetic detection element of the third sensor faces the second magnetic pole, and a magnetic detection element of the fourth sensor faces the first magnetic pole, and the magnetic force of the third sensor. A second region in which a detection element faces the first magnetic pole and a magnetic detection element of the fourth sensor faces the first magnetic pole, and a magnetic detection element of the third sensor acts on the first magnetic pole. Opposing and magnetism of the fourth sensor A third region where the output element faces the second magnetic pole, a magnetic detection element of the third sensor faces the second magnetic pole, and a magnetic detection element of the fourth sensor becomes the second magnetic pole. It is configured to be divided into a fourth region facing each other. In this motor device, a ring magnet or the like composed of an annular magnet is used as a detection target disposed on the side surface of the worm wheel. In this ring magnet, a part of the region is an N pole and the remaining region is an S pole along the circumferential direction. Two magnetic detection elements (Hall IC etc.) are arranged facing this ring magnet, and the rotation area of the worm wheel is divided into four areas by detecting the switching between the S pole and N pole of the ring magnet. To detect.
As a result, a ring magnet or the like is arranged on the side of the worm wheel as a detection target, and two magnetic detection elements (Hall ICs or the like) are arranged as sensors on the worm wheel side, and the rotation area of the worm wheel is divided and detected. In addition, it is possible to detect a failure of the magnetic detection element (sensor) by detecting the switching of the output level of the magnetic detection element accompanying the shift of the rotation region.

A wiper device according to a fourth aspect includes the motor device according to any one of the first to third aspects, and the wiper arm is driven by the motor device to wipe the window glass of the vehicle. The wiper arm is reciprocated between a retracted position, a lower inversion position, and an upper inversion position.
In this wiper device, since the wiper arm is driven by the motor device of the present invention, it is possible to easily detect a failure of the sensor arranged on the worm wheel side in the wiper device. For this reason, when a failure occurs in the sensor on the worm wheel side, the wiper arm can be stopped before it affects other devices.

The invention according to claim 5 is the wiper device according to claim 4 , wherein when the movement of the wiper arm is mechanically restricted and locked, the control unit in the motor device The wiper arm is driven in the direction of the retracted position, and the output state of the third and fourth sensors when the wiper arm is driven in the direction of the retracted position is detected, and the third And a fourth failure determination unit for detecting occurrence of a failure in the fourth sensor.
In this wiper device, when the movement of the wiper arm is mechanically restricted and locked, the wiper arm is once driven toward the retracted position, and the third and fourth sensors (C-phase sensor, The switching of the output state of the D phase sensor) is detected, and the occurrence of a failure in the third and fourth sensors (C phase sensor, D phase sensor) is detected.
Thereby, when the wiper arm is locked, it can be easily determined whether or not a failure of the sensor (C-phase sensor, D-phase sensor) has occurred.

In the motor device of the present invention, the first and second sensors (A phase sensor, B phase sensor) for outputting pulse signals having different phases for detecting the rotation of the motor rotation shaft, and the worm wheel side sensor, 3rd and 4th sensor (C phase sensor, D phase sensor) which detects the rotation position (rotation area | region) of a wheel is provided. Then, when the worm wheel rotates, the switching order of the output states (first level or second level) of the third and fourth sensors (C phase sensor, D phase sensor) on the worm wheel side is detected. Then, the occurrence of an abnormality in these third and fourth sensors (C phase sensor, D phase sensor) is detected.
As a result, when the rotational position of the worm wheel is detected using the third and fourth sensors (C-phase sensor, D-phase sensor), it is possible to easily detect the occurrence of a failure in the two sensors. . For this reason, when a sensor failure on the worm wheel side occurs, the motor can be controlled in a predetermined failure mode, for example, the motor is stopped before other devices are affected.

It is a figure which shows the structure of the motor apparatus concerning embodiment of this invention. It is a figure for demonstrating determination operation | movement of the sensor failure by the worm wheel side by the detection of an area order. It is a flowchart which shows the flow of the sensor failure determination process in an area order failure determination part. It is a figure for demonstrating determination operation | movement of the sensor failure by the worm wheel side by detection of an area width. It is a figure which shows the example of determination operation | movement of a sensor failure by detection of an area width. It is a flowchart which shows the flow of a sensor failure determination process in an area width failure determination part. It is a figure which shows the sensor state corresponding table for determining the failure of the other party sensor at the time of switching of a sensor level. It is a flowchart which shows the flow of the determination process of the sensor failure in the other party sensor level failure determination part. It is a figure for demonstrating the initial operation | movement at the time of the lock of a wiper arm. It is a figure for demonstrating a wiper apparatus. It is a figure which shows the positional relationship of the sensor and ring magnet by the side of a worm wheel. It is a figure which shows the example of the position detection of the wiper arm using the sensor by the side of a worm wheel.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a diagram showing a configuration of a wiper device 1 according to an embodiment of the present invention. The wiper device 1 includes a wiper switch module 2 in which a switch for operating the wiper device 1 is disposed, a motor device 10 that drives and controls the wiper unit 201, and a wiper unit 201. The motor device 10 includes a control unit (CPU) 11, a motor drive circuit 31 having a transistor bridge circuit such as an FET, and a motor unit 101. Note that the motor unit 101 and the wiper unit 201 have the same configuration as the motor unit 101 and the wiper unit 201 shown in FIG. 10 described above. The description to be omitted is omitted.

  As shown in FIG. 1, the control unit 11 includes a wiper drive control unit 12, a motor drive unit 13, a worm wheel side sensor state detection unit 14, a rotation pulse detection unit 15, a motor lock detection unit 15A, and a sensor. It is comprised with the failure determination part 21. FIG. Note that the control unit (CPU) 11 shown in FIG. 1 is configured using a CPU, which is a microcontroller, a custom microcomputer, or the like, and includes a ROM, a RAM, an A / D converter (desired) In some cases, a D / A converter is also included), a counter, an I / O port, a buffer output circuit, and the like. In the control unit 11, the function is realized by the CPU reading a program stored in a ROM built in the CPU itself and executing information processing and arithmetic processing. That is, it is realized by program processing.

The wiper switch module 2 is a module for outputting a wiper operation signal generated by operating a wiper switch provided in a driver's seat or the like to the wiper drive control unit 12. A command signal such as a drive speed is output to the wiper drive control unit 12.
The wiper drive control unit 12 controls the forward / reverse operation and the rotation speed of the motor 111 via the motor drive unit 13 and the motor drive circuit 31 according to the command signal input from the wiper switch module 2, and thereby the wiper arm 202. Is controlled. In addition, the wiper drive control unit 12 includes a failure mode control unit 12A. The failure mode control unit 12A has a failure in one of the worm wheel side sensors (C phase sensor 124 or D phase sensor 125). When this occurs, the wiper arm 202 is driven using the remaining one sensor (C-phase sensor 124 or D-phase sensor 125), or the wiper arm 202 is driven by a certain amount in a predetermined direction and stopped in advance. The motor 111 is controlled so as to operate in a predetermined failure mode.

  The motor drive unit 13 generates a control signal for driving the motor drive circuit 31 in accordance with a control command output from the wiper drive control unit 12. In the motor device 10, PWM control (Pulse Width Modulation) that performs drive control by changing the ON / OFF ratio of the pulse width of the applied voltage is performed on the motor 111. In PWM control, the motor drive unit 13 sets a duty ratio of the pulse voltage ON period and sends a control signal to the motor drive circuit 31. Upon receiving this control signal, the motor drive circuit 31 performs ON / OFF control of each transistor element constituting the FET bridge circuit, and applies a pulse voltage having a set duty to the motor 111. Thereby, the motor 111 is feedback-controlled based on the motor rotation pulse and the absolute position signal.

  The worm wheel side sensor state detection unit 14 receives signals output from the C phase sensor 124 and the D phase sensor 125 on the worm wheel side, and detects the output states of the C phase sensor 124 and the D phase sensor 125. The worm wheel side sensor state detection unit 14 generates a “0 (Low)” or “1 (High)” signal according to the output states of the C-phase sensor 124 and the D-phase sensor 125, and wiper drive control of this signal is performed. Output to the unit 12 and the sensor failure determination unit 21.

The rotation pulse detector 15 detects the rotation speed, rotation direction, and rotation position of the rotation shaft (amateur shaft) of the motor 111 based on the pulse signals output from the A-phase sensor 114 and the B-phase sensor 115. . For example, the number of pulse signals (or pulse intervals) output from the A-phase sensor 114 and the B-phase sensor 115 is measured at predetermined intervals using one counter (not shown) in the CPU, and the motor 111 The rotation speed of is calculated. Further, the rotation pulse detection unit 15 determines the rotation direction of the motor 111 based on two-phase (A and B phase) pulse signals having different phases input from the A phase sensor 114 and the B phase sensor 115.
Further, the rotation pulse detector 15 uses two other counters (A and B phases) input from the A phase sensor 114 and the B phase sensor 115 using another counter (not shown) in the CPU. And the rotational position of the rotating shaft 111a of the motor 111 is calculated.

The rotation pulse detection unit 15 outputs a rotation speed, a rotation direction, and a rotation position signal to the wiper drive control unit 12, and outputs a motor rotation pulse signal to an area width in the motor lock detection unit 15 </ b> A and the sensor failure determination unit 21. Output to the counter 24.
The rotation pulse detection unit 15 is provided with a motor lock detection unit 15A. The motor lock detection unit 15A monitors the state of the motor 111 from the interval (cycle) of the motor rotation pulses output from the rotation pulse detection unit 15. If the pulse period exceeds a predetermined time, it is determined that a motor lock has occurred. Further, the motor lock detector 15A can detect the number of times of lock detection, the elapsed time, and the like. The motor lock state may be detected by monitoring the load current of the motor 111.
When the motor lock state is detected by the motor lock detection unit 15A, the wiper drive control unit 12 drives the motor 111 so that the wiper arm 202 is temporarily returned to the storage position. At this time, the motor lock failure determination unit 27 in the sensor failure determination unit 21 to be described later detects the switching of the output state in the worm wheel side sensor (C phase sensor 124 and D phase sensor 125), and the worm Failure detection of the wheel side sensor is performed.

The sensor failure determination unit 21 detects a failure of the worm wheel side sensor (C phase sensor 124 and D phase sensor 125). The sensor failure determination unit 21 includes an area order failure determination unit 22, an area width failure determination unit 23, an area width count counter 24, a counterpart sensor level failure determination unit 25, a sensor state correspondence table 26, a motor lock. The time failure determination unit 27 is provided (the operation of each unit failure determination unit will be described later).
In the sensor failure determination unit 21, the failure detection processing in the three types of failure determination units (the area order failure determination unit 22, the area order failure determination unit 22, and the counterpart sensor level failure determination unit 25) is always performed in parallel. ing. Then, when a sensor failure is detected in any failure determination unit, the sensor failure information is notified to the wiper drive control unit 12. When the sensor failure information is input from the sensor failure determination unit 21, the wiper drive control unit 12 shifts to the failure mode and stops the motor 111 or uses the remaining one normal sensor by the failure mode control unit 12A. And the wiper operation is continued.

  The sensor state correspondence table 26 is used for failure determination in the counterpart sensor level failure determination unit 25. Further, the motor lock failure determination unit 27 detects the worm wheel side sensors (C phase sensor 124 and D phase sensor 125) during the initial operation described later when the motor lock state is detected by the motor lock detection unit 15A. The switch of the output state is detected, and the failure of the worm wheel side sensor is detected.

[Sensor failure judgment by area order]
Next, the failure determination operation of the C-phase sensor 124 and the D-phase sensor 125 on the worm wheel side performed in the area order failure determination unit 22 will be described. FIG. 2 is a diagram for explaining an operation for determining a sensor failure on the worm wheel side by detecting the area order.

  FIG. 2A shows an example of area shift when the worm wheel side sensors (C phase sensor 124 and D phase sensor 125) are both normal. In the figure, the position of the arm is shown in the horizontal direction, and the output states of the C phase sensor 124 and the D phase sensor 125 are shown side by side in the vertical direction. In the output state of the C-phase sensor 124 and the D-phase sensor 125, “0 (Low)” indicates a state in which the sensor detects the S pole, and “1 (High)” indicates that the sensor detects the N pole. It shows the state.

As shown in FIG. 2A, when the C-phase sensor 124 and the D-phase sensor 125 are normal, when the wiper arm 202 moves from the retracted position to the upper inverted position through the lower inverted position, The output state of the D-phase sensor 125 shifts from “Area (1) → Area (2) → Area (3) → Area (4)”.
That is, the output from the phase C sensor 124 starts from position P1, which is “area (1)” where the output of the phase C sensor 124 is “0” and the output of the phase D sensor 125 is “1”. “1” and the output of the D-phase sensor 125 shifts to “Area (2)” where the output is “1”. It shifts to “area (3)”. Then, after passing through the lower inversion position P4, at the position P5, the process proceeds to “area (4)” where the output of the C-phase sensor 124 is “0” and the output of the D-phase sensor 125 is “0”.
On the contrary, when the wiper arm 202 moves from the upper reversal position to the retracted position via the lower reversal position, “area (4) → area (3) → area (2) depending on the output state of the C-phase sensor 124 and the D-phase sensor 125. → "Area (1)".

  In the area order failure determination unit 22, the area recognition when the wiper arm 202 moves is “area (1) → area (2) → area (3) → area (4)” or “area (1) ← area (2 ) ← Area (3) ← Area (4) ”is not in the order, it is determined that a failure of the C-phase sensor 124 or the D-phase sensor 125 has occurred.

  For example, FIG. 2B shows an example where the C-phase sensor 124 has failed and its output state is fixed at “0 (Low)”. As shown in FIG. 2B, between the positions P2 and P3, the area (2) should be originally recognized, but the output of the C-phase sensor 124 remains “0 (Low)”. Therefore, it is determined as area (1). In addition, between the position P3 and the position P5, the area (3) should be recognized originally, but the output of the C-phase sensor 124 remains “0 (Low)”. It will be judged.

  In this way, when the output of the C-phase sensor 124 is fixed to “0 (Low)”, the area recognition accompanying the movement of the wiper arm 202 is “area (1) → area (4)” or “ “Area (1) ← Area (4)” and areas (2) and (3) cannot be detected, and the normal order of the areas “area (2) → area (3)” or “ This is different from “Area (2) ← Area (3)”. Thereby, it can be detected that a failure has occurred in the C-phase sensor 124.

  For example, FIG. 2C illustrates an example in which the D-phase sensor 125 has failed and its output state is fixed to “1 (High)”. As shown in FIG. 2C, between the positions P3 and P5, the area (3) should be recognized originally, but the output of the D-phase sensor 125 remains “1 (High)”. Therefore, it is determined as area (2). In addition, it should be originally recognized as the area (4) between the position P5 and the position P6, but since the output of the D-phase sensor 125 remains “1 (High)”, the area (1) and It will be judged.

As described above, when the output of the D-phase sensor 125 is fixed to “1 (High)”, the area recognition associated with the movement of the wiper arm to the upper reversal position is “area (2) → area (1 In addition, the area (3) and the area (4) cannot be detected, which is different from the normal recognition of the area order “area (2) → area (3)”. Thereby, it can be detected that a failure has occurred in the D-phase sensor 125.
That is, a number is assigned to a combination of the output states of the C-phase sensor 124 and the D-phase sensor 125 associated with the position of the wiper arm 202, and a failure is detected when the assigned numbers are different from a predetermined order.

FIG. 3 is a flowchart showing the flow of sensor failure determination processing in the area order failure determination unit 22.
When the wiper operation is started (step S101), it is determined whether or not the output state of the C-phase sensor 124 is “1 (High)” (step S102). If the output state of the C-phase sensor 124 is “1 (High)” (Yes in step S102), it is next determined whether or not the output state of the D-phase sensor 125 is “1 (High)”. (Step S103).

  If it is determined in step S103 that the output state of the D-phase sensor 125 is “1 (High)” (Yes in step S103), it is detected that the position of the wiper arm 202 is area (2). (Step S104), the process proceeds to step S109. If it is determined in step S103 that the output state of the D-phase sensor 125 is “0 (Low)” (No in step S103), it is detected that the arm position is area (3) (step S105). The process proceeds to step S109.

  On the other hand, when it is determined in step S102 that the output state of the C-phase sensor 124 is “0 (Low)” (No in step S101), the process proceeds to step S106, and the output state of the D-phase sensor 125 is “ It is determined whether or not it is “1 (High)” (step S106). When it is determined in step S106 that the output state of the D-phase sensor 125 is “1 (High)” (Yes in step S106), it is detected that the position of the wiper arm 202 is area (1). (Step S107), the process proceeds to Step S109. When it is determined in step S106 that the output state of the D-phase sensor 125 is “0 (Low)” (No in step S106), it is detected that the position of the wiper arm 202 is area (4). (Step S108), the process proceeds to Step S109.

In step S109, the difference between the area number of the previous area and the area number of the current area is taken. If the absolute value of the difference exceeds 1 (2 or more) (Yes in step S109), it is determined that the sensor is abnormal. (Step S110). If the absolute value of the difference is 1 or less (1 or 0) (No in step S109), it is determined that the sensor is normal (step S111). As described above, the area order failure determination unit 22 can detect a sensor abnormality by comparing the area numbers of the current area and the previous area.
When the failure shown in FIG. 2C occurs in step S109 of the flowchart shown in FIG. 3, the absolute value of the difference between the area number of the previous area and the area number of the current area becomes 1, and the failure is detected. It becomes impossible. For this reason, other failure determination methods described below are used in combination.

[Sensor failure judgment by area width]
Next, sensor failure determination processing based on area width detection performed in the area width failure determination unit 23 will be described. FIG. 4 is a diagram for explaining an operation for determining a sensor failure on the worm wheel side by detecting the area width.
As shown in FIG. 4, each of the widths of area (1) to area (4) has a unique length, and the length is an A-phase sensor provided on a rotating shaft (amateur shaft) 111a of motor 111. It is detected by counting the pulse signals output from 114 and the B-phase sensor 115 by the area width counter 24. For example, area (3) and area (4) are wider than area (1) and area (2).
Therefore, the area width failure determination unit 23 causes the area width count counter 24 to pass a pulse count number larger by a predetermined amount (+ α) than the pulse count number (preset pulse number) corresponding to each area. If no area switching is detected, it is determined as abnormal (NG).
That is, the rotational position of the worm wheel 121 is divided into four according to the combination of the output states of the C-phase sensor 124 and the D-phase sensor 125, and the driving amount (number of pulses) of the worm wheel 121 in each division is measured in advance. . In each of the four sections, when the driving amount of the worm wheel 121 to be measured exceeds a predetermined amount (+ α) with respect to the driving amount measured in advance, the area width failure determination unit 23 determines whether the C-phase sensor 124 or D A failure of the phase sensor 125 is detected.

FIG. 5 is a diagram illustrating an example of a sensor failure determination operation based on area width detection. FIG. 5A shows an example in which both the C-phase sensor 124 and the D-phase sensor 125 are normal, and FIG. 5B shows a case where the output of the C-phase sensor 124 has failed at a fixed “1 (High)”. An example is shown.
As shown in FIG. 5B, between the position P1 and the position P2, the area (1) should originally be recognized, but the output of the C-phase sensor 124 remains “1 (High)”. Therefore, it is determined as area (2). Further, between the position P5 and the position P6, it should be originally recognized as the area (4), but since the output of the D-phase sensor 125 remains “1 (High)”, the area (3) and It will be judged.

  As described above, when the output of the C-phase sensor 124 is fixed to “1 (High)”, the width of the area recognition is expanded in the area (2) and the area (3). Therefore, for example, when the wiper arm 202 is moved from the lower inversion position to the upper inversion position, if the area (3) is not switched to the area (4) at the position P5, the pulse count number of the width of the area (3) is predetermined. When a threshold value (normal pulse count number + α) is exceeded, it is determined that a sensor abnormality has occurred.

FIG. 6 is a flowchart showing the flow of sensor failure determination processing in the area width failure determination unit 23. Hereinafter, the failure determination process based on the detection of the area width will be described with reference to FIG.
When the wiping operation is started (step S201), it is determined whether or not the output state of the C-phase sensor 124 is switched or the output state of the D-phase sensor 125 is switched (step S202). If it is determined in step S202 that switching has occurred in the C-phase sensor 124 or the D-phase sensor 125 (Yes in step S202), the pulse count number at the time of sensor switching is stored (step S203), and the process proceeds to step S204. To do. On the other hand, if it is determined in step S202 that the output state has not changed in the C-phase sensor 124 or the D-phase sensor 125 (No in step S202), the process proceeds to step S204 as it is.

  In step S204, it is determined whether or not the output state of the C-phase sensor 124 is “1 (High)” (step S204). If the output state of the C-phase sensor 124 is “1 (High)” (Yes in step S204), it is next determined whether or not the output state of the D-phase sensor 125 is “1 (High)”. (Step S205).

  If it is determined in step S205 that the output state of the D-phase sensor 125 is “1 (High)” (Yes in step S205), it is detected that the position of the wiper arm 202 is area (2). (Step S206), the process proceeds to Step S211. If it is determined in step S205 that the output state of the D-phase sensor 125 is “0 (Low)” (No in step S205), it is detected that the arm position is area (3) (step S205). S207), the process proceeds to step S211.

  On the other hand, if it is determined in step S204 that the output state of the C-phase sensor 124 is “0 (Low)” (No in step S204), then the output state of the D-phase sensor 125 is “1 (High)”. It is determined whether or not (step S208). When it is determined that the output state of the D-phase sensor 125 is “1 (High)” (Yes in Step S208), it is detected that the arm position is the area (1) (Step S209), and thereafter The process proceeds to step S211. If it is determined in step S208 that the output state of the D-phase sensor 125 is “0 (Low)” (No in step S208), it is detected that the arm position is area (4) (step S208). After that, the process proceeds to step S211.

In step S211, the difference between the current pulse count number and the pulse count number at the time of sensor switching stored in step S203 is calculated. Whether the absolute value of the difference exceeds the pulse count threshold for each area obtained by adding a predetermined value (+ α) to the pulse count number set in advance corresponding to the width of the area recognized in steps S203 to S210. Determine whether or not.
If it is determined that the absolute value of the difference exceeds the preset pulse count corresponding to the width of the area by a predetermined value (+ α) or more (Yes in step S211), it is determined that the sensor is abnormal ( Step S212). On the other hand, when it is determined that the value is equal to or less than the predetermined value (+ α) (No in step S211), it is determined that the sensor is normal (step S213). As described above, in the area width failure determination unit 23, when the output state of the sensor is switched, the difference between the current pulse count number and the pulse count number at the previous sensor switching is previously determined for each area. By comparing with the set pulse count, it is possible to detect a sensor abnormality of the worm wheel side sensor.

As described above, the area width failure determination unit 23 determines the widths of the four regions divided by the combination of the output states of the two sensors on the worm wheel side (C-phase sensor 124 and D-phase sensor 125) as the motor 111. Measured by the number of pulses output from the sensors (A phase sensor 114 and B phase sensor 115) that detect the rotation of the rotation axis 111a, and detects that the width of each region is a predetermined number of pulses. .
Thereby, it is possible to detect the occurrence of a failure in the worm wheel side sensor (C phase sensor 124 and D phase sensor 125).
Then, by combining the sensor failure determination based on the detection of the area width and the sensor failure determination based on the detection of the area order described above, the worm wheel side sensor (the C-phase sensor 124 and the D-phase sensor 125) can be surely used. The occurrence of a failure can be detected.

[Sensor failure judgment based on partner sensor level when sensor level changes]
Next, the sensor failure determination operation in the counterpart sensor level failure determination unit 25 will be described. That is, an example in which the sensor level of the other party is detected each time the output state (sensor level) of the C-phase sensor 124 and the D-phase sensor 125 is switched, and a sensor failure is determined with reference to the sensor state correspondence table 26 will be described.

  FIG. 7 is a diagram showing a sensor state correspondence table 26 for determining a failure of the counterpart sensor when the sensor level is switched. In the correspondence table shown in FIG. 7, the output state (sensor level) for each of the C-phase sensor 124 and the D-phase sensor 125 in the forward path of the arm (moving toward the upper reverse position) and the return path (moving to the storage position). The other party's sensor level at the time of switching, and the presence or absence of the failure according to this other party's sensor level are shown.

As shown in the figure, when the output state of the C-phase sensor 124 switches from “0 (Low)” to “1 (High)” in the forward path (position P2), if the D-phase sensor 125 is normal, D The output state of the phase sensor 125 is “1 (High)”. Therefore, when the output state of the D-phase sensor 125 is “0 (Low)”, it can be determined that the D-phase sensor 125 has failed.
When the output state of the C-phase sensor 124 switches from “1 (High)” to “0 (Low)” (position P5), if the D-phase sensor 125 is normal, the output state of the D-phase sensor 125 is “0 (Low)”. Therefore, when the output state of the D-phase sensor 125 is “1 (High)”, it can be determined that the D-phase sensor 125 has failed.

  Further, since the state in which the output state of the D-phase sensor 125 is switched from “0 (Low)” to “1 (High)” does not occur in the forward path, the output state of the C-phase sensor 124 in this case is “0 (Low). ) "Or any value of" 1 (High) "(Don't Care). In addition, when the state in which the output state of the D-phase sensor 125 is switched from “0 (Low)” to “1 (High)” occurs in the outward path, it may be determined that the D-phase sensor 125 has failed. .

  In addition, when the output state of the D-phase sensor 125 switches from “1 (High)” to “0 (Low)” in the forward path (position P3), if the C-phase sensor 124 is normal, the C-phase sensor 124 The output state is “1 (High)”. Therefore, when the output state of the C-phase sensor 124 is “0 (Low)”, it can be determined that the C-phase sensor 124 has failed.

On the other hand, in the return path, when the output state of the C-phase sensor 124 switches from “0 (Low)” to “1 (High)” (position P5), if the D-phase sensor 125 is normal, the D-phase sensor 125 The output state is “0 (Low)”. Therefore, when the output state of the D-phase sensor 125 is “1 (High)”, it can be determined that the D-phase sensor 125 has failed.
When the output state of the C-phase sensor 124 switches from “1 (High)” to “0 (Low)” (position P2), if the D-phase sensor 125 is normal, the output state of the D-phase sensor 125 is “1 (High)”. Therefore, when the output state of the D-phase sensor 125 is “0 (Low)”, it can be determined that the D-phase sensor 125 has failed.

  When the output state of the D-phase sensor 125 is switched from “0 (Low)” to “1 (High)” on the return path (position P3), if the C-phase sensor 124 is normal, the C-phase sensor 124 The output state is “1 (High)”. Therefore, when the output state of the C-phase sensor 124 is “0 (Low)”, it can be determined that the C-phase sensor 124 has failed.

Further, since the state in which the output state of the D-phase sensor 125 is switched from “1 (High)” to “0 (Low)” does not occur in the return path, the output state of the C-phase sensor 124 in this case is “0 (Low). ) "Or any value of" 1 (High) "(Don't Care).
If a state in which the output state of the D-phase sensor 125 is switched from “0 (Low)” to “1 (High)” occurs on the return path, it may be determined that the D-phase sensor 125 has failed. .

FIG. 8 is a flowchart showing the flow of sensor failure determination processing in the counterpart sensor level failure determination unit 25. Hereinafter, the flow of the process will be described with reference to FIG.
First, when the operation of the wiper arm 202 is started, it is determined whether or not it is an outward operation (step S301). When it is determined that the operation is the forward operation (Yes in Step S301), the process proceeds to Step S302. On the other hand, when it is determined that the operation is not the forward operation (No in step S301), the process proceeds to step S311.

  In step S302, it is determined whether or not the output state of the C-phase sensor 124 is switched from “0 (Low)” to “1 (High)” and the D-phase is “1 (High)”. Determination is made (step S302). When the output state of the C-phase sensor 124 is switched from “0 (Low)” to “1 (High)”, and the D-phase output state is determined to be “0 (Low)” (Yes in step S302), it is detected that the D-phase sensor 125 is abnormal (step S303), and the process proceeds to step S311. On the other hand, it is determined that “0 (Low)” → “1 (High)” of the output state of the C-phase sensor 124 has not occurred, or the D-phase output state is “1 (High)”. If (No in step S302), the process proceeds to step S304.

  In step S304, the output state of the C-phase sensor 124 switches from “1 (High)” to “0 (Low)”, and the D-phase output state is “1 (High)”. Whether or not (step S304). When the output state of the C-phase sensor 124 switches from “1 (High)” to “0 (Low)” and the D-phase output state is determined to be “1 (High)” (Yes in step S304), it is detected that the D-phase sensor 125 is abnormal (step S305), and the process proceeds to step S311. On the other hand, the output state of the C-phase sensor 124 has not changed from “1 (High)” to “0 (Low)”, or the D-phase output state is “0 (Low)”. (No in step S304), the process proceeds to step S306.

  In step S306, the output state of the D-phase sensor 125 is switched from “1 (High)” to “0 (Low)”, and the output state of the C-phase sensor 124 is “0 (Low)”. It is determined whether or not (step S306). It is determined that the output state of the D-phase sensor 125 is changed from “1 (High)” to “0 (Low)” and the output state of the C-phase sensor 124 is “0 (Low)”. If this is the case (Yes in step S306), it is detected that the C-phase sensor 124 is abnormal (step S307), and the process proceeds to step S311. On the other hand, it is determined that the switching from “1 (High)” to “0 (Low)” of the D phase sensor 125 has not occurred, or the output state of the C phase is “1 (High)”. If (No in step S306), the process proceeds to step S308.

  In step S308, it is determined whether or not the output state of the D-phase sensor 125 has changed from “0 (Low)” to “1 (High)” (step S308). Since this switching state does not occur in the normal state, if it is determined that the output state of the D-phase sensor 125 is switched from “0 (Low)” to “1 (High)” (in step S308). Yes), it is determined that the D-phase sensor 125 is abnormal (step S309), and the process proceeds to step S311. On the other hand, if it is determined that the output state of the D-phase sensor 125 has not changed from “0 (Low)” to “1 (High)” (No in step S308), the C-phase sensor 124 It is determined that both the D phase sensor 125 and the D phase sensor 125 are normal (step S310), and the process proceeds to step S311.

  Subsequently, in step S311, it is determined whether or not the operation is a return path operation (step S311). If it is determined that the operation is the forward operation (Yes in step S311), the process proceeds to step S312. When it is determined that the operation is not the forward operation (No in step S311), the process returns to step S301 again.

  In step S312, whether the output state of the C-phase sensor 124 is switched from “0 (Low)” to “1 (High)”, and whether the D-phase output state is “1 (High)”. It is determined whether or not (step S312). It is determined that the output state of the C-phase sensor 124 is switched from “0 (Low)” to “1 (High)” and the output state of the D-phase sensor 125 is “1 (High)”. If this is the case (Yes in step S312), it is detected that the D-phase sensor 125 is abnormal (step S313), and the process returns to step S301 again. On the other hand, the output state of the C-phase sensor 124 has not changed from “0 (Low)” to “1 (High)”, or the output state of the D-phase sensor 125 is “0 (Low)”. (No in step S312), the process proceeds to step S314.

  In step S314, the output state of the C-phase sensor 124 is switched from “1 (High)” to “0 (Low)”, and the D-phase output state is “0 (Low)”. It is determined whether or not (step S314). It is determined that the output state of the C-phase sensor 124 is switched from “1 (High)” to “0 (Low)” and the output state of the D-phase sensor 125 is “0 (Low)”. If this is the case (Yes in step S314), it is detected that the D-phase sensor 125 is abnormal (step S315), and the process returns to step S301 again. On the other hand, the output state of the C-phase sensor 124 has not changed from “1 (High)” to “0 (Low)”, or the output state of the D-phase sensor 125 is “1 (High)”. (No in step S314), the process proceeds to step S316.

  In step S316, the output state of the D-phase sensor 125 is switched from “0 (Low)” to “1 (High)”, and the output state of the C-phase sensor 124 is “0 (Low)”. It is determined whether or not (step S306). It is determined that the output state of the D-phase sensor 125 is switched from “0 (Low)” to “1 (High)” and the output state of the C-phase sensor 124 is “0 (Low)”. If this is the case (Yes in step S316), it is detected that the C-phase sensor 124 is abnormal (step S317), and the process returns to step S301 again. On the other hand, the output state of the D-phase sensor 125 has not changed from “0 (Low)” to “1 (High)”, or the C-phase output state is “1 (High)”. (No in step S316), the process proceeds to step S318.

  In step S318, it is determined whether or not the output state of the D-phase sensor 125 has changed from “1 (High)” to “0 (Low)” (step S318). Since this switching state does not occur in the normal state, if it is determined that the output state of the D-phase sensor 125 is switched from “1 (High)” to “0 (Low)” (Yes in step S318). ), It is determined that the D-phase sensor 125 is abnormal (step S319), and the process returns to step S301 again. On the other hand, when it is determined that the output state of the D-phase sensor 125 has not been switched from “1 (High)” to “0 (Low)” (No in step S318), the C-phase sensor 124 is used. It is determined that both the D phase sensor 125 and the D phase sensor 125 are normal (step S320), and the process returns to step S301 again.

  As described above, in the counterpart sensor level failure determination unit 25, the output state of the D-phase sensor 125 when the output state of the C-phase sensor 124 is switched and the C-phase sensor 124 when the output state of the D-phase sensor 125 is switched. The output state of the C-phase sensor 124 and the D-phase sensor 125 is determined to be a failure when the output states do not match the predetermined output state. Thereby, it is possible to detect the occurrence of a failure in the worm wheel side sensor (C phase sensor 124 and D phase sensor 125).

  Further, by using the failure determination based on the detection of the counterpart sensor level, the sensor failure determination based on the area order detection described above, and the sensor failure determination based on the area width detection, the worm wheel side sensor ( The occurrence of a failure in the C-phase sensor 124 and the D-phase sensor 125) can be detected.

[Operation after detecting sensor failure]
As the operation after detecting the failure of the worm wheel side sensor, the wiper operation is immediately stopped by the sensor abnormality determination to avoid affecting other devices, and the remaining one normal sensor is used. There is a method to continue the wiper wiping operation. For example, as shown in the above-mentioned Patent Document 1, the position of the wiper arm 202 can be detected by one sensor and the wiping control of the wiper device 1 can be performed. However, the range that can be wiped by the wiper is limited as compared to the case where both the C-phase sensor 124 and the D-phase sensor 125 can be used.

  By the way, when there is an obstacle such as snow and the wiper arm 202 stops in the middle of wiping, or when the wiper switch (or the ignition switch) is turned off, the arm position information (A phase sensor 114 and B phase sensor 115) up to that point is turned off. Output pulse count value) is reset. For this reason, when the wiper is restarted, for example, the wiper arm 202 is once driven to the return path side, and the switching of the output state of the C-phase sensor 124 and the D-phase sensor 125 is detected to detect the storage position, the reverse inversion position, or the origin position. Alternatively, the current arm position detected using the lower limit position contact of the wiper arm 202 (the position regulated by the lower limit bracket) is recognized.

  FIG. 9 is a diagram for explaining a wiper operation when a sensor failure occurs. As shown in FIG. 9A, when the wiper arm 202 starts the wiping operation of the wiper arm 202 at the position Ph, the wiper arm 202 is originally determined to be in the area (4) and returned in the return direction. When the D-phase sensor 125 is faulty, it is determined that it is in the area (1) and starts moving in the forward direction. The wiper arm 202 moves to the bracket position Pb and is mechanically restricted and locked by the bracket. This locked state is detected by a motor lock detector 15A (see FIG. 1) that monitors the rotation period of the motor 111.

  In the locked state of the wiper arm 202, it is determined that the wiper arm 202 is in the area (1) due to the failure of the D-phase sensor 125. Therefore, it is not possible to identify whether the wiper arm 202 is locked due to a sensor failure or snow. . For this reason, when the wiper arm 202 is locked, the initial operation of the wiper arm 202 is performed. In this initial operation, for example, the wiper arm 202 is once driven to the return path side and moved to the retracted position. At this time, the motor lock failure determination unit 27 (see FIG. 1) causes the C phase sensor 124 and the D phase sensor 125 to move. It is determined whether or not a sensor failure has occurred by detecting the switching of the output state at.

For example, when the switching state of the C-phase sensor 124 and the D-phase sensor 125 can be detected, both the C-phase sensor 124 and the D-phase sensor 125 are normal, and the area where the wiper arm 202 is located can be detected. On the other hand, when the switching of the output state cannot be detected in the C-phase sensor 124 or the D-phase sensor 125, it can be detected that an abnormality has occurred in the sensor whose output state does not switch.
As described above, when the wiper arm 202 is locked due to a sensor failure, it is possible to determine which sensor has failed by operating the wiper arm 202 initially, and to set a failure mode according to the determination result. For example, when only one of the C-phase sensor 124 and the D-phase sensor 125 has failed, the failure mode control unit 12A performs the wiper arm wiping operation using the remaining one normal sensor. Can continue.

  Although the embodiment of the present invention has been described above, the correspondence between the present invention and the embodiment will be supplementarily described. In the present invention, the first sensor corresponds to the A-phase sensor 114, the second sensor corresponds to the B-phase sensor 115, the third sensor corresponds to the C-phase sensor 124, and the fourth sensor corresponds to the D-phase sensor 125. Further, the first failure determination unit of the present invention is the area order failure determination unit 22, the second failure determination unit is the area width failure determination unit 23, and the third failure determination unit is the counterpart sensor level failure determination unit 25. The fourth failure determination unit corresponds to the motor lock failure determination unit 27, respectively. Further, the object to be detected on the worm wheel of the present invention corresponds to the ring magnet 123, the first magnetic pole corresponds to the N pole, and the second magnetic pole corresponds to the S pole. In the present invention, the first area on the worm wheel is area (1), the second area is area (2), the third area is area (3), and the fourth area is area (4). ) Respectively. In the present invention, the first level corresponds to “0 (Low)”, and the second level corresponds to “1 (High)”.

The above-described embodiment is a motor device 10 that includes a speed reducer that includes a worm 112 and a worm wheel 121, a motor 111 that drives the worm 112 of the speed reducer, and a control unit 11 that drives the motor 111. Thus, the A phase sensor 114 and the B phase sensor 115 that output pulse signals having different phases according to the rotation of the rotation shaft 111 a of the motor 111 and the ring magnet 123 on the worm wheel 121 in the circumferential direction of the worm wheel 121. The C-phase sensor 124 and the D-phase sensor 125 arranged at different positions along the worm wheel 121 and the output state of “0 (Low)” in the C-phase sensor 124 and the D-phase sensor 125 and “ The order of switching between the output states of 1 (High) ”is a predetermined order. Is determined in advance if the sensor is determined to be a sensor failure by the area order failure determination unit 22 and the area order failure determination unit 22 that detects the occurrence of a failure in the C phase sensor 124 and the D phase sensor 125. And a control unit 11 that operates the motor 111 in the failure mode.
Thus, when the rotational position (area (1) to area (4)) of the worm wheel 121 is detected using the two sensors (C-phase sensor 124 and D-phase sensor 125), the two sensors (C The occurrence of a failure in the phase sensor 124 and the D phase sensor 125) can be easily detected. For this reason, when a failure occurs in the sensor on the worm wheel side (C phase sensor 124 or D phase sensor 125), the motor 111 is stopped in a predetermined failure mode such as stopping the motor 111 before affecting other devices. Can be controlled.

Moreover, in the said embodiment, the width of four area | regions (area (1) -area (4)) divided by the combination of the output state in C phase sensor 124 and D phase sensor 125 is made into A phase sensor 114 and B. C is measured by measuring the number of pulses output from the phase sensor 115 and determining whether or not the width of each region (area (1) to area (4)) is a predetermined pulse count width. The controller 11 further includes an area width failure determination unit 23 that detects the occurrence of a failure in the phase sensor 124 and the D phase sensor 125, and the control unit 11 is determined as a failure in the area order failure determination unit 22 or the area width failure determination unit 23. The motor 111 is operated in a predetermined failure mode.
As a result, the widths of the four regions divided by the output states of the sensors (C phase sensor 124 and D phase sensor 125) on the worm wheel 121 side are output from the sensors (A phase sensor 114 and B phase sensor 115). The failure of the sensors (C phase sensor 124 and D phase sensor 125) can be determined by measuring with pulses.
Then, by combining the sensor failure determination based on the detection of the area width and the sensor failure determination based on the detection of the area order, the occurrence of the failure in the worm wheel side sensor (the C phase sensor 124 and the D phase sensor 125) is more reliably performed. Can be detected.

In the above embodiment, the output state of the D-phase sensor 125 when the output state of the C-phase sensor 124 switches according to the respective forward and reverse rotation directions of the worm wheel 121, and the D-phase sensor 125 The output state of the C-phase sensor 124 when the output state is switched is monitored, and if the output states of the C-phase sensor 124 and the D-phase sensor 125 do not match the predetermined output state, the sensor (the C-phase sensor 124 or The D-phase sensor 125) further includes a counterpart sensor level fault determination unit 25 that determines that a fault has occurred. The control unit 11 includes an area order fault determination unit 22, an area width fault determination unit 23, and a counterpart sensor level fault. When any of the determination units 25 determines that a failure has occurred, the motor 111 is operated in a predetermined failure mode.
As a result, when the output state of the worm wheel side sensor (C phase sensor 124 and D phase sensor 125) is switched, the output state of the counterpart sensor (C phase sensor 124 and D phase sensor 125) is detected. It is possible to detect the occurrence of a failure in (C phase sensor 124 and D phase sensor 125). Further, by using the failure determination based on the detection of the counterpart sensor level, the sensor failure determination based on the detection of the area order, and the sensor failure determination based on the detection of the area width, the worm wheel side sensor ( The occurrence of a failure in the C-phase sensor 124 and the D-phase sensor 125) can be detected.

  Although the embodiment of the present invention has been described above, the motor device and the wiper device of the present invention are not limited to the illustrated examples described above, and various modifications can be made without departing from the scope of the present invention. Of course, it can be added. For example, when the motor 111 is stopped as a failure mode when a failure occurs in any of the worm wheel side sensors by the failure mode control unit 12A, the motor 111 may be driven again by operating the wiper switch module.

DESCRIPTION OF SYMBOLS 1 ... Wiper apparatus, 10 ... Motor apparatus, 11 ... Control part, 12 ... Wiper drive control part, 12A ... Failure mode control part, 13 ... Motor drive part, 14 ... Worm wheel side sensor state detection part, 15 ... Rotation pulse detection , 15A ... motor lock detection unit, 21 ... sensor failure determination unit, 22 ... area order failure determination unit, 23 ... area width failure determination unit, 24 ... area width count counter, 25 ... counterpart sensor level failure determination unit, 26 ... Sensor state correspondence table, 27 ... Motor lock failure determination unit, 31 ... Motor drive circuit, 101 ... Motor unit, 111 ... Motor, 111a ... Rotating shaft, 112 ... Worm, 113 ... Magnet, 114 ... A phase sensor, 115 ... B phase sensor, 121 ... worm wheel, 122 ... wiper shaft, 123 ... ring magnet, 124 ... C phase sensor, 125 ... D phase sensor , 201 ... wiper portion, 202 ... wiper arm, 203 ... wiper blade

Claims (5)

A reduction gear composed of a worm and a worm wheel;
A motor for driving a worm of the speed reducer;
A first sensor and a second sensor that output pulse signals of different phases according to the rotation of the rotation shaft of the motor;
A third sensor and a fourth sensor arranged at different positions along the rotation direction of the worm wheel with respect to the detection target on the worm wheel;
Switching between the first level output state and the second level output state of the third and fourth sensors according to the rotation direction of the worm wheel detected by the first and second sensors. A first failure determination unit for detecting occurrence of a failure in the third and fourth sensors by determining whether or not the order is a predetermined order; and
A control unit that operates the motor in a predetermined failure mode when a sensor failure is detected by the first failure determination unit ;
The rotational position of the worm wheel is divided into four according to the combination of the output states of the third and fourth sensors, and the driving amount of the worm wheel is determined by the number of pulses output from the first and second sensors. Second failure detection for detecting occurrence of failure in the third and fourth sensors by measuring whether or not the driving amount of the worm wheel in each section exceeds a predetermined number of pulses And
With
The control unit further operates the motor in the failure mode when the second failure detection unit determines that a failure has occurred . The output state of the fourth sensor when the output state of the third sensor switches according to the respective forward and reverse rotation directions of the worm wheel detected by the first and second sensors, If the output state of the third sensor is monitored when the output state of the fourth sensor is switched, and the output state of the third and fourth sensors does not match the predetermined output state, the sensor fails. A third failure determination unit that determines that has occurred,
The motor device according to claim 1, wherein the control unit further operates the motor in the failure mode when the third failure determination unit determines that a failure has occurred. The third sensor and the fourth sensor are magnetic detection elements,
The object to be detected on the worm wheel has a first magnetic pole and a second magnetic pole that are arranged on the side surface of the worm wheel on a ring and have different polarities along the circumferential direction,
Depending on the rotation of the worm wheel,
A first region in which the magnetic detection element of the third sensor faces the second magnetic pole and the magnetic detection element of the fourth sensor faces the first magnetic pole;
A second region in which the magnetic detection element of the third sensor faces the first magnetic pole and the magnetic detection element of the fourth sensor faces the first magnetic pole;
A third region in which the magnetic detection element of the third sensor faces the first magnetic pole and the magnetic detection element of the fourth sensor faces the second magnetic pole;
A fourth region in which the magnetic detection element of the third sensor faces the second magnetic pole and the magnetic detection element of the fourth sensor faces the second magnetic pole;
The motor device according to claim 1, wherein the motor device is configured to be divided into two types. A motor device according to any one of claims 1 to 3 , wherein the wiper arm is driven by the motor device to wipe a window glass of the vehicle, and the wiper arm is moved to a retracted position, a lower inverted position, and an upper position. A wiper device that reciprocates between reversal positions. When the movement of the wiper arm is mechanically restricted and locked,
The control unit in the motor device is
Detecting the switching of output states of the third and fourth sensors when the wiper arm is driven toward the retracted position and the wiper arm is driven toward the retracted position; The wiper device according to claim 4 , further comprising a fourth failure determination unit that detects occurrence of a failure in the fourth sensor.

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