JP2019043158A - Wiper device - Google Patents

Abstract

To provide a wiper device that can suppress costs for a sensor related to detection of a position of a wiper blade.SOLUTION: A microcomputer 58 determines that wiper blades 28 and 30 reach a storage position P3 as a reference position on the basis of motor currents detected when wiper arms 24 and 26 come into contact with stoppers 54A and 54B. Further, the microcomputer 58 calculates positions of the wiper blades 28 and 30 from the reference position on the basis of a rotation speed of a rotor of the wiper motor 18 detected by a Hall sensor 72 and a speed reduction ratio of a deceleration mechanism 52 of the wiper motor 18, and controls a driving circuit 56 so that rotation of the wiper motor 18 reverses when the positions of the wiper blades 28 and 30 reach an upper reverse position P1 or a lower reverse position P2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wiper device.

  The wiper apparatus pivots the wiper arm by rotating the wiper motor forward and reverse, and reciprocates between the upper reversal position and the lower reversal position of the windshield glass of the vehicle with a wiper blade connected to the tip of the wiper arm. Wipe away. In order to invert the wiper blade in the upper inversion position and the lower inversion position, it is necessary to detect the position of the wiper blade on the windshield glass. In many wiper devices, the rotation angle of the output shaft of the wiper motor is detected by a sensor such as an MR sensor (magnetic resistance sensor) that detects the magnetic field of the sensor magnet provided at the end of the output shaft of the wiper motor The position of the wiper blade is calculated from

  However, the MR sensor is expensive, which increases the manufacturing cost of the wiper device. Patent Document 1 discloses an invention of a brushless wiper motor that detects a magnetic field of a sensor magnet provided at an end of an output shaft with a Hall sensor that is cheaper than an MR sensor.

JP, 2013-223317, A

  However, since it is difficult to detect the direction of rotation with only one Hall sensor, the brushless wiper motor described in Patent Document 1 detects the rotation angle and the direction of rotation of the output shaft with two Hall sensors. However, there is still a problem that the manufacturing cost of the wiper device is increased.

  The present invention is made in view of the above, and it aims at providing a wiper device which can control cost of a sensor concerning detection of a position of a wiper blade.

  According to a first aspect of the present invention, there is provided a wiper apparatus including: a wiper motor that causes a wiper blade to perform a wiping operation within a predetermined wiping range on a windshield; and a rotation number detection unit that detects the number of rotations of the wiper motor. The position of the wiper blade from the reference position is calculated based on the reference position detection unit that detects the arrival of the wiper blade at the reference position of the wiping range, and the rotation speed of the wiper motor detected by the rotation speed detection unit. And a control unit for performing rotation control such that the rotation of the wiper motor is reversed when the position of the wiper blade reaches either the upper reversing position or the lower reversing position.

  According to this wiper device, the cost of the sensor related to the position detection of the wiper blade can be suppressed by calculating the position of the wiper blade from the number of rotations detected by the sensor used for rotation control of the wiper motor.

  The wiper apparatus according to claim 2 is the wiper apparatus according to claim 1, wherein the reference position is any one of a storage position below the lower reversing position and the upper reversing position. Wiper device.

  According to this wiper device, the position of the wiper blade from the reference position can be accurately calculated by detecting the storage position or the upper reverse position as the reference position.

  The wiper apparatus according to claim 3 is the wiper apparatus according to claim 1 or 2, wherein the reference position detection unit restricts rotation of the wiper motor when the wiper blade reaches the reference position. And a current detection unit for detecting the current of the wiper motor, wherein the control unit determines that the wiper blade has reached the reference position when the current detected by the current detection unit is equal to or greater than a threshold current. The cumulative rotation number of the wiper motor detected by the rotation number detection unit is reset to zero.

  According to this wiper device, since the current sensor that detects the current of the wiper motor detects that the wiper blade has reached the reference position, the cost of the sensor related to the detection of the position of the wiper blade can be suppressed.

  The wiper apparatus according to claim 4 is the wiper apparatus according to claim 1 or 2, wherein the reference position detection unit is a switch which is turned on when the wiper blade reaches the reference position. The unit resets the cumulative rotation number of the wiper motor detected by the rotation number detection unit to 0 when the switch is on.

  According to this wiper device, since the low cost switch using the piezoelectric element or the like detects that the wiper blade has reached the reference position, the cost of the sensor related to the position detection of the wiper blade can be suppressed.

  The wiper apparatus according to claim 5 is the wiper apparatus according to any one of claims 1 to 4, wherein the rotational speed detection unit is a Hall sensor that detects a position of a magnetic pole of a rotor of the wiper motor. The control unit calculates the position of the wiper blade from the reference position based on the number of rotations of the rotor detected by the hall sensor and the reduction ratio of the output shaft of the wiper motor.

  According to this wiper device, the cost of the sensor related to the position detection of the wiper blade can be suppressed by calculating the position of the wiper blade from the number of rotations detected by the Hall sensor used for the rotation control of the wiper motor.

It is the schematic which shows the structure of the wiper apparatus which concerns on the 1st Embodiment of this invention. It is a block diagram showing an outline of an example of composition of a wiper control device concerning a 1st embodiment of the present invention. It is an explanatory view showing an example of wiping operation of a wiper device concerning a 1st embodiment of the present invention, and (A) is a CLOSE operation in which a wiper blade carries out wiping operation from a top inversion position to a storing position. The state where the position is reached is shown, (B) shows the state where the wiper blade has reached the lower inversion position by the OPEN operation in which the wiper blade wipes from the storage position to the upper inversion position, (C) shows the wiper blade by the OPEN operation. 28 and 30 have shown the state which reached the upper inversion position. FIG. 6 is an explanatory view in which a waveform of a motor current of the wiper device according to the first embodiment of the present invention, a rotation number counter value detected by a hall sensor, and a position of the wiper blade are associated with each other. It is the flowchart which showed an example of the rotation speed counter value reset process of the wiper apparatus concerning the 1st Embodiment of this invention. It is the schematic which shows the structure of the wiper apparatus which concerns on the 2nd Embodiment of this invention.

First Embodiment
FIG. 1 is a schematic view showing a configuration of a wiper device 100 according to the present embodiment. The wiper device 100 is, for example, for wiping a windshield glass (wind shield) 12 provided in a vehicle such as a passenger car, and includes a pair of wipers 14 and 16, a wiper motor 18, and a link mechanism 20; And a wiper control device 10.

  The wipers 14 and 16 are composed of wiper arms 24 and 26 and wiper blades 28 and 30, respectively. The proximal ends of the wiper arms 24 and 26 are respectively fixed to pivot shafts 42 and 44 described later, and the wiper blades 28 and 30 are respectively fixed to distal ends of the wiper arms 24 and 26.

  In the wipers 14 and 16, the wiper blades 28 and 30 reciprocate on the windshield glass 12 in accordance with the operation of the wiper arms 24 and 26, and the wiper blades 28 and 30 wipe the windshield glass 12.

  The wiper motor 18 is a brushless DC motor including a stator that is an electromagnet that generates a rotating magnetic field by controlling an applied voltage in the circumferential direction of a rotor configured by permanent magnets. The wiper motor 18 has an output shaft 32 that can be rotated forward and reverse via a reduction mechanism 52 mainly composed of a worm gear, and the link mechanism 20 includes a crank arm 34, a first link rod 36, and a pair of pivots The lever 38, 40, the pair of pivot shafts 42, 44 and the second link rod 46 are provided.

  One end of the crank arm 34 is fixed to the output shaft 32, and the other end of the crank arm 34 is operatively connected to one end of the first link rod 36. Also, the other end of the first link rod 36 is operatively connected to a point near an end different from the end having the pivot shaft 42 of the pivot lever 38, and the end having the pivot shaft 42 of the pivot lever 38 The two ends of the second link rod 46 are respectively operatively connected to different ends and the end of the pivot lever 40 corresponding to the end of the pivot lever 38.

  Also, the pivot shafts 42, 44 are movably supported by a pivot holder (not shown) provided on the vehicle body, and the end of the pivot levers 38, 40 having the pivot shafts 42, 44 is via the pivot shafts 42, 44. Thus, the wiper arms 24 and 26 are respectively fixed.

  In the wiper device 100 including the wiper control device 10 according to the present embodiment, when the output shaft 32 is rotated forward and reverse at a rotation angle θ1 of a predetermined range, the rotational force of the output shaft 32 is transmitted via the link mechanism 20. The wiper blades 28 and 30 reciprocate between the lower reversing position P2 and the upper reversing position P1 on the windshield glass 12 as the wiper arms 24 and 26 reciprocate. The value of θ1 can take various values depending on the configuration of the link mechanism of the wiper device and the like, but in the present embodiment, it is 140 ° as an example.

  In the wiper device 100 including the wiper control device 10 according to the present embodiment, as shown in FIG. 1, when the wiper blades 28 and 30 are positioned at the storage position P3, the crank arm 34 and the first link rod 36 are in a linear configuration.

  The storage position P3 is provided below the lower inversion position P2. When the output shaft 32 rotates by θ2 from the state where the wiper blades 28 and 30 are at the lower reversing position P2, the wiper blades 28 and 30 move to the storage position P3. The value of θ2 can take various values depending on the configuration of the link mechanism of the wiper device and the like, but in this embodiment, it is 10 ° as an example. When θ2 is “0”, the lower reversal position P2 and the storage position P3 coincide with each other, and the wiper blades 28 and 30 stop at the lower reversal position P2 and are stored. Further, in the present embodiment, the stoppers 54A, 54B are provided to prevent the downward swing of the wiper arms 24, 26 when the wiper blades 28, 30 are positioned at the storage position P3. Although the stoppers 54A and 54B are provided in FIG. 1, only the stopper 54A for stopping the swing of the wiper arm 24 or only the stopper 54B for stopping the swing of the wiper arm 26 may be provided. Further, the stoppers 54A, 54B may be provided to stop the operation of the wiper blades 28, 30 instead of the wiper arms 24, 26, or the stoppers 54A, 54B may be provided to stop the operation of the pivot levers 38, 40. Good.

  A wiper control device 10 for controlling the rotation of the wiper motor 18 is connected to the wiper motor 18. The wiper control device 10 according to the present embodiment generates, for example, a current for operating the wiper motor 18 by PWM (Pulse Width Modulation) control by PWM control and supplies the drive circuit 56 to the wiper motor 18 and the position of the rotor of the wiper motor 18 It has a Hall sensor 72 for detecting. Further, a thermistor 102 for detecting the temperature of the substrate is mounted on the substrate of the wiper control device 10.

  In the present embodiment, since the wiper motor 18 is a brushless DC motor, the drive circuit 56 includes an inverter circuit using a MOSFET as a switching element, and generates a voltage of a predetermined duty ratio by control of a microcomputer 58 described later.

  Since the wiper motor 18 according to the present embodiment has the reduction mechanism 52 as described above, the rotation speed and the rotation angle of the output shaft 32 are not the same as the rotation speed and the rotation angle of the wiper motor main body. The microcomputer 58 of the wiper control device 10 according to the present embodiment calculates the rotation angle of the output shaft 32 by multiplying the rotation speed (and rotation angle) of the rotor detected by the hall sensor 72 by the reduction ratio of the reduction mechanism 52. From the calculated rotation angle of the output shaft 32, the position of the wiper blades 28, 30 on the windshield glass 12 is calculated.

  The microcomputer 58 of the wiper control device 10 can calculate the position of the wiper blades 28 and 30 on the windshield glass 12 from the rotational speed of the rotor detected by the hall sensor 72, and the rotational speed of the output shaft 32 according to the position. Controls the drive circuit 56 to change. In addition, the wiper control device 10 has a memory 48 storing data and programs used to control the drive circuit 56. The microcomputer 58 of the wiper control device 10 has a wiper via a host ECU (Electronic Control Unit) 90. The switch 50 is connected. The memory 48 is, for example, a non-volatile storage device such as an HDD (Hard Disk Drive) or a flash memory.

  The microcomputer 58 calculates the position of the rotor of the wiper motor 18 based on the signal output from the hall sensor 72. The microcomputer 58 also controls the drive circuit 56 to generate a voltage having a phase based on the calculated position of the rotor.

  The wiper switch 50 is a switch that turns on or off the power supplied to the wiper motor 18 from the battery of the vehicle, which is a power supply. The wiper switch 50 has a Lo mode selection position for operating the wiper blades 28 and 30 at a low speed, a Hi mode selection position for operating at a high speed, an INT mode selection position for intermittently operating at fixed intervals, and a storage (stop) mode selection position. Can be switched to Further, it outputs to the microcomputer 58 a signal of a rotational speed command corresponding to the selected position of each mode.

  When a signal output from the wiper switch 50 according to the selected position of each mode is input to the microcomputer 58, the microcomputer 58 performs control corresponding to the output signal from the wiper switch 50.

  FIG. 2 is a block diagram schematically showing an example of the configuration of the wiper control device 10 according to the present embodiment. The wiper motor 18 shown in FIG. 2 is, for example, a three-phase six-pole DC brushless motor. The rotor 88 of the wiper motor 18 is comprised of three S pole and N pole permanent magnets. The magnetic field of the rotor 88 is detected by the Hall sensor 72. The Hall sensor 72 may detect the magnetic field of a sensor magnet provided separately from the rotor 88 in accordance with the polarity of the permanent magnet of the rotor 88. The Hall sensor 72 detects the magnetic field of the rotor 88 or sensor magnet as a magnetic field that indicates the position of the rotor 88.

  A signal output from the hall sensor 72 is input to a microcomputer 58 which is a control circuit. The microcomputer 58 is an integrated circuit, and the power supplied from the battery 80, which is a power supply, is controlled by the standby circuit 60.

  A signal input from the Hall sensor 72 to the microcomputer 58 is a sine wave analog signal, but is converted into a rectangular wave digital signal by the Hall sensor edge detection unit 66 in the microcomputer 58. In addition, the Hall sensor edge detection unit 66 detects an edge where the digital signal changes from high level to low level or from low level to high level.

  The digital signal and edge information are input to the motor position estimation unit 64, and the motor position estimation unit 64 calculates the position of the rotor 88. Information on the calculated position of the rotor 88 is input to the energization control unit 68. Further, the energization control unit 68 calculates the position of the wiper blades 28 and 30 on the windshield glass 12 from the signal of the hall sensor 72.

  A signal for instructing the rotational speed of the wiper motor 18 (rotor 88) from the wiper switch 50 via the upper ECU 90 is input to the command value calculation unit 62 of the microcomputer 58. The command value calculation unit 62 extracts a command related to the rotational speed of the wiper motor 18 from the signal input from the wiper switch 50, and inputs the command to the energization control unit 68.

  The energization control unit 68 calculates the phase of the voltage that changes according to the position of the rotor 88 and the positions of the wiper blades 28 and 30 calculated by the motor position estimation unit 64, and is instructed by the calculated phase and the wiper switch 50. Based on the rotational speed of the rotor 88, the drive duty value is determined. Further, the energization control unit 68 performs PWM control of generating a PWM signal which is a pulse signal corresponding to the drive duty value and outputting the PWM signal to the drive circuit 56.

  The drive circuit 56 is configured of a three-phase (U-phase, V-phase, W-phase) inverter. As shown in FIG. 2, the drive circuit 56 includes three N-channel field effect transistors (MOSFETs) 74U, 74V, and 74W (hereinafter referred to as "FETs 74U, 74V, and 74W") as upper stage switching elements, respectively. It has three N-channel field effect transistors (MOSFETs) 76U, 76V, 76W (hereinafter referred to as "FETs 76U, 76V, 76W") as lower stage switching elements. The FETs 74U, 74V, 74W and the FETs 76U, 76V, 76W are collectively referred to as "FET 74" and "FET 76" when there is no need to distinguish them individually, and when it is necessary to distinguish them, "U" , "V", "W" with the symbols attached.

  Of the FET 74 and the FET 76, the source of the FET 74U and the drain of the FET 76U are connected to the terminal of the coil 86U, and the source of the FET 74V and the drain of the FET 76V are connected to the terminal of the coil 86V. The source of the FET 74W and the FET 76W The drain is connected to the terminal of the coil 86W. Coils 86U, 86V, 86W are collectively referred to as "coil 86" when it is not necessary to distinguish them individually, and when it is necessary to distinguish them, "U", "V", "W" It is called with the sign of.

  The gates of the FET 74 and the FET 76 are connected to the conduction control unit 68, and a PWM signal is input. The FET 74 and the FET 76 are turned on when an H level PWM signal is input to their gates, and a current flows from the drain to the source. In addition, when an L level PWM signal is input to the gate, the transistor is turned off, and no current flows from the drain to the source.

  In the present embodiment, the thermistor 102 is mounted near the drive circuit 56 configured by the FETs 74U, 74V, 74W, 76U, 76V, and 76W which are switching elements. The thermistor 102 is an element whose resistance value changes with temperature, and constitutes a voltage dividing circuit together with the resistor 104. The voltage divided by the resistor 104 and the thermistor 102 is input to the conduction control unit 68. The energization control unit 68 detects the temperature of the substrate on which the FETs 74U, 74V, 74W, 76U, 76V, 76W are mounted based on the input voltage, and when the temperature of the substrate becomes equal to or higher than a predetermined threshold value By reducing the rotational speed of the wiper motor 18, overheating of the substrate and the like is eliminated.

  A current detection unit 92 for detecting the current (motor current) of the drive circuit 56 and the wiper motor 18 is provided between the source of each of the FETs 76U, 76V and 76W and the battery 80. Current detection unit 92 includes a shunt resistance having a resistance value of about 0.2 mΩ to several Ω, and an amplifier for detecting a potential difference between both ends of the shunt resistance which changes according to the motor current and amplifying a signal of the detected potential difference. . Then, the signal output from the amplifier is input to the energization control unit 68.

  Further, in the wiper control device 10 of the present embodiment, a power supply 80, a noise prevention coil 82, smoothing capacitors 84A, 84B, and the like are configured. The power supply 80, the noise prevention coil 82, and the smoothing capacitors 84A and 84B substantially constitute a DC power supply.

  FIG. 3 is an explanatory view showing an example of the wiping operation of the wiper apparatus 100 according to the present embodiment. FIG. 3A is a CLOSE operation in which the wiper blades 28 and 30 perform the wiping operation from the upper reversing position P1 to the storage position P3. Shows that the wiper blades 28, 30 have reached the storage position P3, and (B) shows that the wiper blades 28, 30 are inverted by the OPEN operation in which the wiper blades 28, 30 perform the wiping operation from the storage position P3 to the upper reversing position P1. A state in which the position P2 is reached is shown, and (C) shows a state in which the wiper blades 28 and 30 have reached the upper reverse position P1 by the OPEN operation.

  In the state shown in FIG. 3A, the wiper arms 24 and 26 abut against the stoppers 54A and 54B to prevent swinging, and the rotation of the wiper motor 18 is stopped. In such a state, the wiper motor 18 is temporarily overloaded, and the motor current detected by the current detection unit 92 is increased as described later.

  FIG. 4 is an explanatory view in which the waveform of the motor current of the wiper apparatus 100 according to the present embodiment, the rotational speed counter value detected by the hall sensor 72, and the positions of the wiper blades 28 and 30 are associated with each other. In FIG. 4, the wiper blades 28 and 30 stopped between the upper reversing position P 1 and the lower reversing position P 2 move to the storage position P 3 in the CLOSE operation, and the wiper arms 24 and 26 abut against the stoppers 54 A and 54 B It shows the state. As a result, the rotation of the output shaft 32 of the wiper motor 18 is restrained, the wiper motor 18 is temporarily overloaded, and an overload current 110 exceeding the threshold current is detected. Although the threshold current varies depending on the specification of the wiper motor 18, it is lower than the overload current 110, and the normal motor current has a clearly higher current value, and is specifically determined through experiments of a real machine or the like.

  When the microcomputer 58 detects the overload current 110, it resets the rotation number counter value, which is the cumulative rotation number, to "0". The positions of the wiper blades 28 and 30 that can be calculated from the number of rotations (rotational angle) of the rotor 88 by the hall sensor 72 are relative positions indicating how much they have moved from the reference position.

  The wiping operation of the wiper device 100 is susceptible to external force by traveling wind or the like, and when the external force acts on the wiper device during the wiping operation, the calculated relative position is the position of the original wiper blade 28 or 30 There is a risk of coming off.

  Therefore, it is necessary to detect the reference position in order to calculate the absolute position of the wiper blades 28 and 30, and in the present embodiment, when the overload current 110 is detected, the wiper arm 24 at the storage position P3 26 abuts on the stoppers 54A and 54B, and it is determined that the wiper blades 28 and 30 have reached the storage position P3 which is the reference position, and the rotation number counter value is reset.

  After resetting the rotation number counter value, when the rotation number counter value reaches the upper reverse predetermined value 114, it is determined that the wiper blades 28 and 30 have reached the upper reverse position P1, and the rotation of the wiper motor 18 is reversed. . Furthermore, when the rotation number counter value reaches the lower reverse predetermined value 116, it is determined that the wiper blades 28 and 30 have reached the lower reverse position P2, and the rotation of the wiper motor 18 is reversed and the rotation number counter value is decreased. The reverse initial value 118 is set, and the wiping operation to the upper reverse position P1 is started.

  FIG. 5 is a flowchart showing an example of the rotation number counter value reset process of the wiper apparatus 100 according to the present embodiment. In step 500, the CLOSE direction in which the wiper blades 28, 30 stopped between the upper reversing position P1 and the lower reversing position P2 or the wiper blades 28, 30 stopping at the lower reversing position P2 are moved to the storage position P3. Perform the wiping operation.

  In step 502, based on the detection of the overload current 110, the revolution counter value is reset to "0" to determine the reference position. In step 504, the OPEN direction wiping operation is performed from the storage position P3 toward the upper reverse position P1, and the process is ended.

  As described above, according to the present embodiment, the windshield glass 12 of the wiper blades 28 and 30 is based on the output signal from the Hall sensor 72 for detecting the position of the rotor 88 of the wiper motor 18 which is a brushless DC motor. Calculate the upper position. The positions of the wiper blades 28 and 30 detected by the hall sensor 72 for detecting the position of the rotor 88 are relative positions from the reference position. Therefore, in the present embodiment, the storage position P3 is set as the reference position, and the wiper blade 28 When 30 reaches the storage position P3, the rotation number counter value of the hall sensor 72 is reset to "0".

  Further, in the present embodiment, when the current detection unit 92 for detecting the motor current detects the overload current 110, it is determined that the wiper blades 28 and 30 have reached the storage position P3. Even if there is no position detection dedicated sensor, it is possible to detect the position of the wiper blades 28 and 30 on the windshield glass 12.

  Although the wiper apparatus 100 having the link mechanism 20 is illustrated in the present embodiment, it may be a so-called direct drive type wiper apparatus in which the end portion of the wiper arm is connected to the output shaft of the wiper motor without the link mechanism 20. . In such a wiper device, the stopper is provided at a position where the swing of the wiper blade or the wiper arm can be stopped when the wiper blade is positioned at the storage position P3.

  In the present embodiment, the so-called tandem type wiper device 100 having the link mechanism 20 and the wiper blades 28 and 30 performing the wiping operation substantially in parallel is illustrated, but in the case where the wiper device is a direct drive type In addition to the tandem type, it may be a so-called opposed type wiper apparatus in which two wiper blades are opposed at the lower reversing position P2 (or the storage position P3).

  In the present embodiment, the wiper motor 18 is a brushless DC motor which is a type of three-phase synchronous motor, but may be a brushed DC motor. When the wiper motor 18 is a brushed DC motor, a hall sensor for detecting the rotation of the rotor or the output shaft 32 of the wiper motor 18 is separately required. However, the hall sensor detects the absolute rotation angle of the output shaft 32 of the wiper motor 18 Since the cost is lower than that of the MR sensor, the manufacturing cost of the wiper device can be reduced.

  In the present embodiment, sensors that can detect that the wiper arms 24, 26 such as piezoelectric sensors or the wiper blades 28, 30 abut on at least one of the stoppers 54A, 54B may be provided. Since the piezoelectric sensor is cheaper than the MR sensor, the manufacturing cost of the wiper device can be reduced.

  In the present embodiment, the storage position P3 located below the lower inversion position P2 is used as the reference position, but the reference position may be the upper inversion position P1. When the wiper blades 28 and 30 reach the upper reversing position P1, stoppers 54A and 54B are provided at positions where the swing of the wiper arms 24 and 26 is stopped, and when the wiper blades 28 and 30 reach the upper reversing position P1 The load current 110 may be detected. Alternatively, sensors such as a piezoelectric sensor may be provided on at least one of the stoppers 54A and 54B to detect that the wiper blades 28 and 30 have reached the upper reverse position P1 which is the reference position.

Second Embodiment
Subsequently, a second embodiment of the present invention will be described. As shown in FIG. 6, the wiper apparatus 200 according to the present embodiment is different from the wiper apparatus 200 in that it includes a stopper 146 for stopping the rotation of the crank arm 34 instead of the stoppers 54A and 54B for stopping the swing of the wiper arms 24 and 26. This differs from the wiper device 100 according to the first embodiment. However, since the other configuration is the same as that of the first embodiment, the same configuration as that of the first embodiment is denoted by the same reference numeral as that of the first embodiment, and the detailed description is omitted.

  As shown in FIG. 6, in the wiper apparatus 200 in which the driving force of the wiper motor 18 is distributed to the wiper arms 24 and 26 by the link mechanism 20, only the stopper 146 for stopping the rotation of the crank arm 34 close to the output shaft 32 of the wiper motor 18 is provided. Thus, it is possible to stop the swing of the wiper arms 24 and 26. Therefore, according to the present embodiment, the swing of the wiper arms 24 and 26 is stopped with a configuration simpler than that of the first embodiment, and the storage position P3 is wiped by detection of the overload current 110 accompanying the stop. It becomes possible to set it as the reference position of position detection of blade 28,30.

  In the present embodiment, the so-called tandem type wiper device 100 having the link mechanism 20 and the wiper blades 28 and 30 performing the wiping operation substantially in parallel is illustrated, but in the case where the wiper device is a direct drive type In addition to the tandem type, it may be a so-called opposed type wiper apparatus in which two wiper blades are opposed at the lower reversing position P2 (or the storage position P3).

  In the embodiment, the wiper motor 18 is a brushless DC motor which is a kind of three-phase synchronous motor, but may be a brushed DC motor. When the wiper motor 18 is a brushed DC motor, a hall sensor for detecting the rotation of the rotor or the output shaft 32 of the wiper motor 18 is separately required. However, the hall sensor detects the absolute rotation angle of the output shaft 32 of the wiper motor 18 Because the cost is lower than that of the MR sensor, it is possible to prevent an increase in the manufacturing cost of the wiper device.

  In the present embodiment, the stopper 146 may be provided with sensors capable of detecting that the crank arm 34 such as a piezoelectric sensor is in contact. Since the piezoelectric sensor is cheaper than the MR sensor, the manufacturing cost of the wiper device can be reduced.

  In the present embodiment, the storage position P3 located below the lower inversion position P2 is used as the reference position, but the reference position may be the upper inversion position P1. A stopper 146 is provided at a position to stop the rotation of the crank arm 34 when the wiper blades 28 and 30 reach the upper reversing position P1, and the overload current 110 is obtained when the wiper blades 28 and 30 reach the upper reversing position P1. It may be detected. Alternatively, sensors such as a piezoelectric sensor may be provided on the stopper 146 to detect that the wiper blades 28 and 30 have reached the upper reverse position P1 which is the reference position.

DESCRIPTION OF SYMBOLS 10 Wiper control device 12 Windshield glass 14, 16 Wiper 18 Wiper motor 20 Link mechanism 24, 26 Wiper arm 28, 30 Wiper blade 32 Output shaft 34 Crank arm DESCRIPTION OF SYMBOLS 36 ... Link rod, 38, 40 ... Pivot lever, 42, 44 ... Pivot axis, 46 ... Link rod, 48 ... Memory, 50 ... Wiper switch, 52 ... Deceleration mechanism, 54A, 54B ... Stopper, 56 ... Drive circuit, 58 ... microcomputer, 60 ... standby circuit, 62 ... command value calculation unit, 64 ... motor position estimation unit, 66 ... Hall sensor edge detection unit, 68 ... energization control unit, 72 ... Hall sensor, 74 (74U, 74V, 74W) , 76 (76 U, 76 V, 76 W) ... FET, 80 ... power supply, 80 ... battery, 82 ... noise prevention Coil, 84A, 84B: Smoothing capacitor, 86 (86U, 86V, 86W): Coil, 88: Rotor, 90: Upper ECU, 92: Current detection unit, 100: Wiper device, 102: Thermistor, 104: Resistance, 110: ... Overload current, 114: upper inversion predetermined value, 116: lower inversion predetermined value, 118: lower inversion initial value, 146: stopper, 200: wiper device, θ1: rotation angle, P1: upper inversion position, P2: lower inversion position , P3 ... storage position

Claims (5)

A wiper motor for wiping the wiper blade within a predetermined wiping range on the windshield;
A rotation number detection unit that detects the rotation number of the wiper motor;
A reference position detection unit that detects the arrival of the wiper blade at a reference position of the wiping range;
The position of the wiper blade from the reference position is calculated based on the number of rotations of the wiper motor detected by the rotation number detection unit, and the position of the wiper blade has reached either the upper reverse position or the lower reverse position. A control unit that performs rotation control such that the rotation of the wiper motor is reversed at the time of
Wiper apparatus including.   The wiper apparatus according to claim 1, wherein the reference position is either a storage position below the lower reversing position or the upper reversing position. The reference position detection unit includes a rotation restraint unit that restrains the rotation of the wiper motor when the wiper blade reaches the reference position, and a current detection unit that detects a current of the wiper motor.
The control unit determines that the wiper blade has reached the reference position when the current detected by the current detection unit is equal to or greater than a threshold current, and the cumulative rotation number of the wiper motor detected by the rotation number detection unit is The wiper device according to claim 1 or 2, which is reset to 0. The reference position detection unit is a switch that is turned on when the wiper blade reaches the reference position.
The wiper apparatus according to claim 1, wherein the control unit resets the cumulative rotation number of the wiper motor detected by the rotation number detection unit to 0 when the switch is on. The rotation speed detection unit is a Hall sensor that detects the position of the magnetic pole of the rotor of the wiper motor,
The said control part calculates the position of the said wiper blade from the said reference position based on the rotation speed of the said rotor detected by the said hall | hole sensor, and the reduction ratio of the output shaft of the said wiper motor. The wiper device according to any one of the items.