JP6658783B2 - Wiper control device - Google Patents

Description

  The present invention relates to a wiper control device.

  A wiper device for wiping a windshield glass of a vehicle with a wiper blade has a low-speed operation mode in which the wiper blade operates at a low speed and a high-speed operation mode in which the wiper blade operates at a high speed. FIG. 11 is a schematic diagram illustrating an example of characteristics required for the wiper motor in the high-speed operation mode and the low-speed operation mode. The high-speed operation motor output required characteristic 94 requires a high motor rotation speed, and the low-speed operation motor output required characteristic 96 requires a large torque as compared with the high-speed operation mode. As a result, in order to satisfy the motor output required characteristic 94 during high speed operation and the motor output required characteristic 96 during low speed operation, it is necessary to satisfy the motor output required characteristic 92 shown by a thick solid line.

  However, according to the required motor output characteristics 92 shown in FIG. 11, the rating of the wiper motor must be increased, which may lead to an increase in the size of the wiper device and an increase in manufacturing cost. Further, when the rating of the wiper motor is determined in accordance with the motor output required characteristic 92, an excessive region 98, which is a region of the motor rotation speed and the torque that is not required in the high-speed operation mode or the low-speed operation mode, accompanies the characteristics of the wiper motor. There was a problem that it was not used.

  A factor that hinders an increase in the rotation speed of the motor is a back electromotive force generated in the armature of the motor as the motor rotates. The back electromotive force has a polarity opposite to the voltage applied to the motor, and impedes the current of the armature of the motor. When the back electromotive force is generated in the armature, the rotation speed of the motor does not increase even if the voltage applied to the motor is increased.

  Patent Document 1 discloses a brushless motor and a wiper device that controls a voltage applied to a coil of a stator, suppresses the generation of a back electromotive force by a field weakening to weaken the magnetic field of the stator, and improves the rotation speed of the motor. Have been.

JP 2013-198188 A

  However, the brushless motor and the wiper device described in Patent Literature 1 have a problem that although the rotation speed of the motor is improved by weakening the magnetic field of the stator, the torque of the motor may be reduced. .

  The present invention has been made in view of the above, and an object of the present invention is to provide a wiper control device capable of improving a rotation speed of a wiper motor while securing a necessary torque.

In order to solve the above problem, the wiper control device according to claim 1 is connected to a wiper arm to which a wiper blade for wiping a windshield glass is attached, and a rotor configured by a permanent magnet, and a rotating magnetic field generated by the rotor. A coil for rotating the rotor, and a magnetic field detecting unit for detecting a magnetic field indicating the position of the rotor and outputting a signal corresponding to the magnetic field, wherein the rotation of the rotor causes a lower inversion position and an upper inversion position of the windshield glass. A low-speed operation mode for outputting a command to reduce the speed of the reciprocating operation of the wiper blade, and a high-speed operation for outputting a command to increase the speed of the reciprocating operation of the wiper blade. reduced to slow the wiper switch capable of switching to either one of the selected position of the mode, the speed of the wiper motor A sensor magnet attached to the center of the bottom surface of a worm wheel attached to an end of the output shaft opposite to the end to which the crank arm for reciprocating the wiper arm is connected, and the speed reduction mechanism A rotation angle sensor disposed directly below the speed reduction mechanism and mounted on a substrate mounted with a microcomputer for controlling a voltage supplied to the wiper motor in a housing that accommodates the sensor magnet. A rotation angle detector , corresponding to the position of the wiper blade on the windshield glass and the selected position of the wiper switch , calculated from the rotation angle of the output shaft determined based on a signal output by the rotation angle detector. and determines the rotation speed of the wiper motor in response to a command and output Te The phase of the voltage that changes according to the position of the rotor determined based on the signal output by the magnetic field detection unit is calculated, and the phase of the calculated voltage is set so that the wiper motor rotates at the determined rotation speed. based on each of the change of the current value and the induced voltage so as to match each phase of the current value and the induced voltage generated in the coil of the coil in the speed of command output corresponding to the selected position of the wiper switch A determining unit that changes the angle at an angle corresponding to the predetermined electrical angle to determine the phase of the voltage applied to the coil, and a drive circuit that applies a voltage having the phase determined by the determining unit to the coil. Have.

  According to this wiper control device, the phase corresponding to the position of the rotor is advanced by an electrical angle corresponding to the speed of the command output by the wiper switch, and a voltage having the advanced phase is applied to the coil of the wiper motor. I have.

  Generally, when the current flowing through the coil is large, the magnetic field of the coil becomes strong. Further, the current of the coil of the brushless DC motor shows a phase delayed with respect to the phase of the voltage applied to the coil. Therefore, by advancing the phase of the voltage applied to the coil of the motor so that the phase of the current of the coil approaches the phase corresponding to the position of the rotor, the torque and rotation speed of the motor can be improved. Therefore, according to the wiper control device, it is possible to improve the rotational speed of the wiper motor while securing a necessary torque.

A wiper control device according to a second aspect is the wiper control device according to the first aspect, wherein the determining unit is configured to input a command to change a reciprocating speed of the wiper blade to a high speed from the wiper switch. Advances the phase of the voltage that changes according to the calculated position of the rotor at an angle corresponding to a predetermined electrical angle determined in advance so that the phases of the current value of the coil and the induced voltage generated in the coil match. The angled phase is the phase of the voltage applied to the coil.

  According to the wiper control device, by advancing the phase of the voltage applied to the coil of the motor, the rotation speed of the wiper motor can be improved while securing the required torque during high-speed operation.

  A wiper control device according to a fourth aspect of the present invention is the wiper control device according to the second or third aspect, wherein the determination unit receives a command from the wiper switch to change a reciprocating speed of the wiper blade to a low speed. In this case, the phase of the voltage that changes according to the position of the rotor is set as the phase of the voltage applied to the coil.

  According to this wiper control device, by setting the phase of the voltage that changes according to the position of the rotor to the phase of the voltage applied to the coil, the wiper motor can be rotated at a rotation speed and torque suitable for low-speed operation. .

  A wiper control device according to a fifth aspect of the present invention is the wiper control device according to the fourth aspect, wherein the rotational speed of the wiper motor is set to a value corresponding to the rotational speed of the wiper blade when the reciprocating speed of the wiper blade is low and high, respectively. The windshield glass further includes a storage unit for storing a low speed and a high speed specified in accordance with a position on the windshield glass, wherein the determination unit changes the speed of the reciprocating operation of the wiper blade from the wiper switch to a low speed. When a command to input is performed, the rotational speed of the wiper motor is determined in accordance with the calculated position of the wiper blade based on the low speed, and the wiper motor is rotated at the determined rotational speed. The phase that changes according to the calculated rotor position is set as the phase of the voltage applied to the coil, and the phase is changed from the wiper switch to the When a command to change the speed of the reciprocating operation of the wiper blade to high speed is input, the rotation speed of the wiper motor is determined based on the calculated position of the wiper blade based on the high speed speed, and the determined rotation speed is determined. A phase obtained by advancing a phase that changes according to the calculated position of the rotor so that the wiper motor rotates at a speed at an angle corresponding to a predetermined electrical angle is defined as a phase of a voltage applied to the coil.

  According to this wiper device, the rotational speed of the wiper motor according to the position of the wiper blade on the windshield glass is determined by referring to a speed map or the like in which the rotational speed of the wiper motor is predetermined according to the position of the wiper blade. it can.

  Further, according to the wiper control device, by increasing the phase of the voltage applied to the coil of the wiper motor by a predetermined electrical angle, it is possible to improve the rotation speed of the wiper motor while securing the required torque during high-speed operation. Can be.

1 is a schematic diagram illustrating a configuration of a wiper device including a wiper control device according to an embodiment of the present invention. It is a schematic diagram showing a position of a sensor of a wiper motor concerning an embodiment of the invention. FIG. 3 is a cross-sectional view illustrating a cross section of the wiper motor taken along a line AA illustrated in FIG. 2. It is a block diagram showing an outline of an example of composition of a wiper control device concerning an embodiment of the invention. FIG. 3 is a diagram illustrating an example of an outline of an analog waveform of a voltage output by a Hall sensor included in each phase of a wiper motor and an example of an outline of a digital waveform obtained from the analog waveform via a circuit such as a comparator. In the wiper control device according to the embodiment of the present invention, (A) is a schematic diagram showing aspects of an applied voltage applied to a coil, an induced voltage generated in the coil by rotation of a rotor, and a winding current flowing through the coil. (B) shows the case where there is no advance control in which a voltage is applied to the coil according to the position of the rotor, and (B) shows the case where there is advance control in which the timing of applying the voltage to the coil is advanced from the position of the rotor. In a wiper device including a wiper control device according to an embodiment of the present invention, when the wiper blade reciprocates between a lower inversion position and an upper inversion position on a windshield glass, the wiper blade corresponds to the position of the wiper blade. FIG. 4 is a schematic diagram illustrating an example of a speed map that defines a rotation speed of a wiper motor. FIG. 2 is a schematic diagram illustrating an example of a change in a voltage (Duty) applied to a wiper motor when a wiper blade operates from a lower inversion position to an upper inversion position in a wiper device including a wiper control device according to an embodiment of the present invention. It is. FIG. 4 is a schematic diagram illustrating an example of a characteristic of an output of a wiper motor enabled by a wiper control device according to an embodiment of the present invention. 5 is a flowchart illustrating an example of control in the wiper control device according to the embodiment of the present invention. FIG. 4 is a schematic diagram illustrating an example of characteristics required of a wiper motor in a high-speed operation mode and a low-speed operation mode.

  FIG. 1 is a schematic diagram illustrating a configuration of a wiper device 100 including a wiper control device 10 according to the present embodiment. The wiper device 100 is for wiping a windshield glass 12 provided in a vehicle such as a passenger car, for example, and includes a pair of wipers 14 and 16, a wiper motor 18, a link mechanism 20, a wiper control device 10 and the like. And

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

  In the wipers 14, 16, the wiper blades 28, 30 reciprocate on the windshield glass 12 with the operation of the wiper arms 24, 26, and the wiper blades 28, 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 a voltage applied in a circumferential direction of a rotor formed of a permanent magnet. The wiper motor 18 has an output shaft 32 that can be rotated forward and backward through a reduction mechanism 52 mainly constituted by a worm gear. The link mechanism 20 includes a crank arm 34, a first link rod 36, and a pair of pivots. It includes levers 38 and 40, a pair of pivot shafts 42 and 44, and a second link rod 46.

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

  The pivot shafts 42 and 44 are operably supported by a pivot holder (not shown) provided on the vehicle body, and ends of the pivot levers 38 and 40 having the pivot shafts 42 and 44 are interposed therebetween. 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 within a predetermined range, the rotational force of the output shaft 32 is transmitted via the link mechanism 20. The power is transmitted to the wiper arms 24 and 26, and the wiper blades 28 and 30 reciprocate between the lower reversing position P2 and the upper reversing position P1 on the windshield glass 12 with the reciprocating operation of the wiper arms 24 and 26. The value of θ1 can take various values depending on the configuration of the link mechanism of the wiper control 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, 30 are located at the storage position P3, the crank arm 34 and the first link rod 36 are configured to be linear.

  The storage position P3 is provided below the lower inversion position P2. When the output shaft 32 rotates by θ2 from the state in which the wiper blades 28 and 30 are at the lower inversion 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 the present embodiment, is set to 10 ° as an example.

  When θ2 is “0”, the lower inversion position P2 and the storage position P3 match, and the wiper blades 28 and 30 stop at the lower inversion position P2 and are stored.

  A wiper control device 10 for controlling rotation of the wiper motor 18 is connected to the wiper motor 18. The wiper control device 10 according to the present embodiment controls, for example, PWM (Pulse Width Modulation) control of a rotation angle sensor 54 for detecting the rotation speed and rotation angle of the output shaft 32 of the wiper motor 18, and a current for operating the wiper motor 18. The drive circuit 56 includes a drive circuit 56 that is generated and supplied to the wiper motor 18, and a Hall sensor 72 for detecting the position of the rotor of the wiper motor 18.

  In this 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 having a predetermined duty ratio under the control of a microcomputer 58 described later.

  Since the wiper motor 18 according to the present embodiment has the speed 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. However, in the present embodiment, since the wiper motor main body and the speed reduction mechanism 52 are integrally formed as an integral part, the rotation speed and the rotation angle of the output shaft 32 will be regarded as the rotation speed and the rotation angle of the wiper motor 18 below. .

  The rotation angle sensor 54 is provided in the speed reduction mechanism 52 of the wiper motor 18 and converts a magnetic field (magnetic force) of a sensor magnet that rotates in conjunction with the output shaft 32 into a current and detects the current.

  The wiper control device 10 can calculate the positions of the wiper blades 28 and 30 on the windshield glass 12 from the rotation angle of the output shaft 32 detected by the rotation angle sensor 54, and the rotation speed of the output shaft 32 is changed according to the positions. The microcomputer 58 controls the driving circuit 56 so as to change. Further, the wiper control device 10 has a memory 48 storing data and a program used for controlling the drive circuit 56, and a microcomputer 58 of the wiper control device 10 is connected to a wiper switch 50. The memory 48 is a non-volatile storage device such as a hard disk drive (HDD) 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 controls the drive circuit 56 so as to generate a voltage having a phase based on the calculated rotor position.

  The wiper switch 50 is a switch that turns on or off electric power supplied to the wiper motor 18 from a battery of the vehicle, which is a power supply. The wiper switch 50 includes a low-speed operation mode selection position for operating the wiper blades 28 and 30 at low speed, a high-speed operation mode selection position for operating at high speed, an intermittent operation mode selection position for intermittently operating at a constant cycle, and storage (stop). It can be switched to the mode selection position. The microcomputer 58 also outputs to the microcomputer 58 a signal of a command for a rotational speed corresponding to the selected position of each mode.

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

  FIG. 2 is a schematic diagram showing a position of a sensor of wiper motor 18 according to the present embodiment. As shown in FIG. 2, the wiper motor 18 is provided with a coil 86 that generates a rotating magnetic field in the circumferential direction of a rotor 88 composed of a permanent magnet and is adjacent to the coil 88. A Hall sensor 72 for detection is provided. If the wiper motor 18 is a three-phase DC brushless motor, the Hall sensors 72 are provided for each of the three phases of U-phase, V-phase, and W-phase.

  A worm 52A is formed at an end of a rotor shaft 88A extending from the rotor 88, and the worm 52A meshes with a worm wheel 52B formed integrally with the output shaft 32. In the present embodiment, the worm 52A and the worm wheel 52B constitute the speed reduction mechanism 52.

  A sensor magnet 70 is attached to an end of the output shaft 32 opposite to the end to which the crank arm 34 is attached, and a rotation angle sensor 54 is provided to face the sensor magnet 70.

  FIG. 3 is a cross-sectional view showing a cross section of the wiper motor 18 taken along the line AA shown in FIG. The worm 52A is spirally formed along the axial direction of the rotor shaft 88A. The worm wheel 52B is formed in a disk shape, and has a spur tooth groove formed along the circumferential direction thereof. The meshing of the spiral groove of the worm 52A and the tooth groove of the worm wheel 52B enables the rotation of the rotor 88 to be reduced at a predetermined reduction ratio and transmitted to the output shaft 32. A sensor magnet 70 is attached to the center of the bottom surface of the worm wheel 52A corresponding to the end of the output shaft 32.

  A substrate 90 of the wiper control device 10 according to the present embodiment is provided immediately below the speed reduction mechanism 52 in the upper housing 78A. On the substrate 90, a microcomputer 58, elements constituting the drive circuit 56, and the like are mounted. Further, a portion of the substrate 90 facing the sensor magnet 70 provided at an end of the output shaft 32 detects a magnetic field of the sensor magnet 70 that changes according to the rotation of the output shaft 32, and outputs a signal indicating a change in the magnetic field. Is output.

  FIG. 4 is a block diagram schematically illustrating an example of the configuration of the wiper control device 10 according to the present embodiment. The wiper motor 18 shown in FIG. 4 is, for example, a three-phase six-pole DC brushless motor.

  The rotor 88 of the wiper motor 18 is composed 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 a 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 the sensor magnet as a magnetic field indicating the position of the rotor 88.

  The Hall sensor 72 is a sensor for detecting the position of the rotor 88 by detecting a magnetic field formed by the rotor 88 or the sensor magnet. The Hall sensor 72 includes three Hall elements corresponding to U, V, and W phases. The Hall sensor 72 outputs a change in the magnetic field caused by the rotation of the rotor 88 as a signal of a change in voltage such as analog waveforms 102U, 102V, and 102W approximated to a sine wave shown in FIG. FIG. 5 is a diagram showing an example of a schematic example of an analog waveform of a voltage output by the Hall sensor 72 provided for each phase of the wiper motor 18 and an example of a digital waveform obtained by obtaining the analog waveform via a circuit such as a comparator. is there.

  The 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 power supply 80 is controlled by the standby circuit 60.

  The analog waveform signal input from the Hall sensor 72 to the microcomputer 58 is input to a Hall sensor edge detection unit 66 provided in the microcomputer 58 and provided with a circuit for converting an analog signal into a digital signal, such as a comparator. The Hall sensor edge detector 66 converts the input analog waveforms 102U, 102V, 102W into digital waveforms 104U, 104V, 104W shown in FIG. 5, and converts the digital waveforms 104U, 104V, 104W into edges 106A, 106B, 106C. , 106D, 106E and 106F are detected.

  Information on the digital waveforms 104U, 104V, 104W and edges 106A, 106B, 106C, 106D, 106E, 106F is input to the motor position estimating unit 64, and the position of the rotor 88 is calculated. Information on the calculated position of the rotor 88 is input to the energization control unit 68.

  Further, a signal for instructing the rotation speed of the wiper motor 18 (the rotor 88) is input from the wiper switch 50 to the command value calculation unit 62 of the microcomputer 58. The command value calculation unit 62 extracts a command related to the rotation 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 calculated by the motor position estimating unit 64, and based on the calculated phase and the rotation speed of the rotor 88 specified by the wiper switch 50. To determine the drive duty value. Further, the energization control unit 68 performs PWM control for 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 by a three-phase (U-phase, V-phase, W-phase) inverter. As shown in FIG. 4, 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”) each serving as an upper-stage switching element. It includes three N-channel field effect transistors (MOSFETs) 76U, 76V, and 76W (hereinafter, referred to as “FETs 76U, 76V, and 76W”) as lower-stage switching elements. The FETs 74U, 74V, 74W and the FETs 76U, 76V, 76W are collectively referred to as "FET74" and "FET76", respectively, when there is no need to distinguish between them. , “V” and “W”.

  Of the FETs 74 and 76, the source of the FET 74U and the drain of the FET 76U are connected to the terminal of the coil 86U, the source of the FET 74V and the drain of the FET 76V are connected to the terminal of the coil 86V, and the source of the FET 74W and the The drain is connected to the terminal of the coil 86W.

  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 the gate, and a current flows from the drain to the source. 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.

  The wiper control device 10 according to the present embodiment includes a power supply 80, a noise prevention coil 82, and smoothing capacitors 84A and 84B. The power supply 80, the noise prevention coil 82, and the smoothing capacitors 84A and 84B constitute a substantially DC power supply.

  FIG. 6 shows a mode of an applied voltage 112 applied to the coil 86, an induced voltage 114 generated in the coil 86 by rotation of the rotor 88, and a winding current 116 flowing through the coil 86. FIG. In the case where there is no advance control in which a voltage is applied to the coil 86 according to the position of the rotor 88 calculated by the motor position estimating unit 64, (B) indicates that the position of the rotor 88 calculated by the motor position estimating unit 64 is shifted to the coil 86 This is a case where there is advance control with an earlier voltage application timing. FIG. 6 shows items that apply to all of the U phase, the V phase, and the W phase.

  In general, in a brushless DC motor, a voltage applied to the wiper motor 18 without advancing angle control, which generates a voltage having a phase corresponding to the position of the rotor 88 calculated based on a signal output from the Hall sensor 72, is controlled. Also in the present embodiment, when the wiper device 100 is in the low-speed operation mode, the voltage applied to the wiper motor 18 is controlled without advance control.

  6A and 6B, the phase of the induced voltage 114 corresponds to the position of the rotor 88. That is, the peak 114A of the induced voltage 114 indicates when the S-pole or N-pole magnet forming the rotor 88 comes closest to the coil 86 where the induced voltage 114 is generated. If the winding current 116, which is the current flowing through the coil when the induced voltage 114 indicates the peak 114A, is maximized as shown by the peak 116A, the interaction between the rotor 88 and the coil 86 due to the mutual magnetic field becomes strong, and as a result, As a result, high-efficiency control that achieves both high-speed rotation and torque of the wiper motor 18 can be performed.

  In order to match the appearance timing of the peak 114A of the induced voltage 114 with the appearance timing of the peak 116A of the winding current 116, the phases of the induced voltage 114 and the winding current 116 may be matched. Further, the phase of the winding current 116 is affected by the phase of the applied voltage 112. For example, as shown in FIG. 6B, the phase of the applied voltage 112 is advanced (advanced) by a predetermined electrical angle α from the phase corresponding to the position of the rotor 88, so that the induced voltage 114 and the winding The phases of each of the currents 116 can be matched.

  The electrical angle α related to the advance angle is determined based on changes in the winding current 116 of the coil 86 and the induced voltage 114. In the present embodiment, the electrical angle α is, for example, 60 to 90 degrees.

  In the present embodiment, the phase of the voltage that changes according to the position of the rotor 88 determined based on the signal output from the Hall sensor 72 is calculated, and in the case of the low-speed operation mode, the voltage changes according to the position of the rotor. The driving circuit 56 is controlled so as to generate a voltage having a phase. In the case of the high-speed operation mode, advance control is performed to cause the drive circuit 56 to generate a voltage having a phase obtained by advancing a phase that changes according to the position of the rotor 88 by a predetermined electrical angle α. As described above, in the present embodiment, the phase of the voltage applied to the coil 86 of the wiper motor 18 is changed at an angle corresponding to the electrical angle corresponding to the speed of the wiper motor 18 so that the rotation speed and the torque of the wiper motor 18 are changed. Performs compatible control.

  FIG. 7 shows the rotation of the wiper motor 18 according to the position of the wiper blades 28, 30 when the wiper blades 28, 30 reciprocate between the lower inversion position P2 and the upper inversion position P1 on the windshield glass 12. It is the schematic which shows an example of the speed map which prescribed | regulated the speed. To realize the high-speed operation mode and the low-speed operation mode, a high-speed operation mode speed map 122 and a low-speed operation mode speed map 124 are set and stored in the memory 48 in advance. However, as shown in FIG. 7, in the high-speed operation mode speed map 122 and the low-speed operation mode speed map 124, the rotational speeds of the wiper motor 18 are both 0 at the lower inversion position P2 and the upper inversion position P1. Further, the high-speed operation mode speed map 122 and the low-speed operation mode speed map 124 indicate that the rotation speed of the wiper motor 18 is increased or decreased, for example, the rotation speed of the wiper motor 18 is maximized at a substantially intermediate point between the lower inversion position P2 and the upper inversion position P1. Respectively coincide with each other.

  Therefore, the rotation speed of the wiper motor indicated by the high-speed operation mode speed map 122 may be calculated by multiplying the rotation speed of the wiper motor 18 indicated by the low-speed operation mode speed map 124 by a predetermined coefficient. By calculating the high-speed operation mode speed map 122 based on the low-speed operation mode speed map 124, the storage capacity of the memory 48 can be saved.

  FIG. 8 shows a voltage applied to the wiper motor 18 when the wiper blades 28 and 30 operate from the lower inversion position P2 to the upper inversion position P1 in the wiper device 100 including the wiper control device 10 according to the present embodiment. FIG. 9 is a schematic diagram illustrating an example of a change in (Duty). The low-speed operation voltage 134 is a case where the low-speed operation mode speed map 124 shown in FIG. 7 is used and there is no advance control, and the high-speed operation voltage 132 is a high-speed operation mode speed map 122 shown in FIG. In this case, the angle is used and the advance angle is controlled. As a result of improving the efficiency of the rotation control of the wiper motor 18 by the advance angle control, the high-speed operation voltage 132 becomes higher than the low-speed operation voltage 134, and the rotation speed of the wiper motor 18 can be improved. .

  FIG. 9 is a schematic diagram illustrating an example of an output characteristic of the wiper motor 18 enabled by the wiper control device 10 according to the present embodiment. Without the advance angle control, even the wiper motor 18 indicating the rotation speed and the torque indicated by the low-speed operation mode output characteristic 144 can be rotated at the rotation speed and the torque indicated by the high-speed operation mode output characteristic 142 by the advance angle control. Becomes

  FIG. 10 is a flowchart illustrating an example of control in wiper control device 10 according to the present embodiment. In step 700, it is determined whether or not the wiper switch 50 is in the high-speed operation mode. If the determination is affirmative, in step 702, advance control is performed to advance the timing of applying the voltage of the wiper motor 18 by the electrical angle α. If a negative determination is made in step 700, the advance angle control is not performed in step 704. It is assumed that the timing of applying the voltage to the wiper motor 18 is calculated as needed according to the phase of the voltage calculated from the signal from the Hall sensor 72 as described above.

  In step 706, the positions of the wiper blades 28 and 30 are calculated based on the signal from the rotation angle sensor 54, and the rotation speed of the wiper motor 18 and the actual rotation speed of the wiper motor 18 in the speed map corresponding to the positions are added. To perform the rotation speed feedback. The rotation speed feedback uses, for example, PI control (Proportional Integral Controller) or the like to add the actual rotation speed of the wiper motor 18 calculated based on the signal from the hall sensor 72 to the rotation speed of the wiper motor 18 in the speed map. .

  In step 708, a voltage to be applied to the wiper motor 18 is generated so that the rotation speed becomes the rotation speed based on the rotation speed feedback, and the process returns. In step 708, when the advance angle control is performed, the phase of the voltage applied to the wiper motor 18 is advanced by the electrical angle α from the phase corresponding to the position of the rotor 88.

  As described above, according to the present embodiment, it is possible to improve the rotational speed of the wiper motor while securing the required torque by performing the advance control that advances the timing of applying the voltage of the wiper motor 18 by the electrical angle α. Becomes

  In the present embodiment, the advance angle control is performed when the wiper device 100 is in the high-speed operation mode. However, the advance angle control may be performed also in the low-speed operation mode. For example, the torque of the wiper motor 18 can be improved even in the low-speed operation mode by advancing the phase of the voltage applied to the coil 86 at an electrical angle corresponding to the low-speed operation mode, which is different from the high-speed operation mode. it can.

DESCRIPTION OF SYMBOLS 10 ... Wiper control apparatus, 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, 36 link rod, 38, 40 pivot lever, 42, 44 pivot shaft, 46 link rod, 48 memory, 50 wiper switch, 52 reduction mechanism, 52A worm, 52B worm wheel, 54 rotation Angle sensor, 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: conduction control unit, 70: sensor magnet , 72 ... Hall sensor, 74 (74U, 74V, 74W) ... FET, 76 (76U) 76V, 76W) ... FET, 78A ... upper housing, 78B ... lower housing, 80 ... power supply, 82 ... noise prevention coil, 84A ... smoothing capacitor, 86 (86U, 86V, 86W) ... coil, 88 ... rotor, 88A ... rotor Shaft, 92: required motor output characteristics, 94: required motor output characteristics at high speed operation, 96: required motor output characteristics at low speed operation, 98: excess region, 100: wiper device, 102U, 102V, 102W: analog waveform, 104U, 104V, 104W: digital waveform, 106A, 106B, 106C, 106D, 106E, 106F: edge, 112: applied voltage, 114: induced voltage, 114A: peak of induced voltage, 116: winding current, 116A: winding current Peak, 122: high-speed operation mode speed map, 124: low-speed operation mode Speed map, 132: high-speed operation voltage, 134: low-speed operation voltage, 142: high-speed operation mode output characteristic, 144: low-speed operation mode output characteristic, P1: upper inversion position, P2: lower inversion position, P3: storage position , Α: electrical angle, θ1: rotation angle

Claims (5)

The rotor is connected to a wiper arm to which a wiper blade for wiping the windshield glass is attached, and a rotor constituted by a permanent magnet, a coil for rotating the rotor with a generated rotating magnetic field, and a magnetic field indicating the position of the rotor are detected. A wiper motor that includes a magnetic field detection unit that outputs a signal corresponding to a magnetic field, and that causes the wiper arm to reciprocate between a lower inversion position and an upper inversion position of the windshield glass by rotation of the rotor;
A wiper that can be switched to any one of a low-speed operation mode that outputs a command to reduce the speed of the reciprocating operation of the wiper blade and a high-speed operation mode that outputs a command to increase the speed of the reciprocating operation of the wiper blade. Switches and
A reduction mechanism configured to reduce the speed of the wiper motor is attached to the center of the bottom surface of the worm wheel attached to the end of the output shaft opposite to the end where the crank arm for reciprocating the wiper arm is connected. A sensor magnet and a housing in which the speed reduction mechanism is accommodated, disposed directly below the speed reduction mechanism and mounted on a substrate on which a microcomputer for controlling a voltage supplied to the wiper motor is mounted, facing the sensor magnet; A rotation angle sensor including a rotation angle sensor;
A command output in accordance with a position of the wiper blade on the windshield glass and a selected position of the wiper switch on the windshield glass calculated from a rotation angle of the output shaft determined based on a signal output by the rotation angle detection unit. The rotational speed of the wiper motor is determined in accordance with the rotational speed of the wiper motor, and the phase of a voltage that changes in accordance with the position of the rotor determined based on the signal output by the magnetic field detection unit is calculated. as but match each phase of the induced voltage generated in the current value and the coil of the coil in the speed command output in response the phase of the voltage the calculated in a selected position of the wiper switch to rotate mark to the coil to change the angle corresponding to an electrical angle determined in advance based on the change of each of the current value and the induced voltage A determination unit which determines the phase of the voltage,
A drive circuit that applies a voltage having the phase determined by the determination unit to the coil,
A wiper control device having:   The determining unit, when a command to change the speed of the reciprocating operation of the wiper blade to a high speed is input from the wiper switch, the phase of the voltage that changes according to the calculated rotor position, the current value of the coil and 2. The wiper according to claim 1, wherein a phase advanced by an angle corresponding to a predetermined electrical angle determined in advance so that respective phases of induced voltages generated in the coil match each other is set as a phase of a voltage applied to the coil. 3. Control device.   The wiper control device according to claim 2, wherein the predetermined electrical angle is 60 to 90 degrees.   When a command to change the speed of the reciprocating operation of the wiper blade to a low speed is input from the wiper switch, the determining unit changes a phase of a voltage that changes according to the position of the rotor to a voltage applied to the coil. The wiper control device according to claim 2, wherein the wiper control device is a phase. The rotational speed of the wiper motor when the speed of the reciprocating operation of the wiper blade is low and high is stored according to the position of the wiper blade on the windshield glass. Further comprising a storage unit
The determining unit, when a command to change the reciprocating speed of the wiper blade to a low speed is input from the wiper switch, the wiper motor corresponding to the calculated position of the wiper blade based on the low speed. The rotation speed of the wiper motor is determined, and the phase that changes in accordance with the calculated position of the rotor so that the wiper motor rotates at the determined rotation speed is defined as the phase of the voltage applied to the coil. When a command to change the speed of the reciprocating operation to a high speed is input, the rotation speed of the wiper motor according to the calculated position of the wiper blade is determined based on the high speed speed, and the determined rotation speed is determined. The phase that changes according to the calculated position of the rotor so that the wiper motor rotates corresponds to a predetermined electrical angle. Wiper control apparatus according to angles in advance is not phase in claim 4, the phase of the voltage applied to the coil.