JP2018102128A - Wiper control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiper control device capable of improving a rotational speed of a wiper motor while securing necessary torque.SOLUTION: A microcomputer 58 calculates a position of a rotor 88 on the basis of a signal output from a Hall sensor 72. In addition, the microcomputer 58, in a case where a command of lowering a speed of a reciprocating operation of a wiper blade is input from a wiper switch 50, controls a drive circuit 56 so as to generate a voltage that has a phase changing according to the calculated position of the rotor 88. Further, the microcomputer 58, in a case where a command of increasing the speed of the reciprocating operation of the wiper blade is input from the wiper switch 50, controls the drive circuit 56 so as to generate a voltage that has a phase obtained by advancing the phase changing according to the calculated position of the rotor 88 by a predetermined electric angle.SELECTED DRAWING: Figure 4

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 is operated at a low speed and a high speed operation mode in which the wiper blade is operated 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 motor output requirement characteristic 94 for high speed operation requires a higher motor rotation speed, and the motor output requirement characteristic 96 for low speed operation requires a larger torque than in the high speed operation mode. As a result, in order to satisfy the motor output requirement characteristic 94 for high speed operation and the motor output requirement characteristic 96 for low speed operation, it is necessary to satisfy the motor output requirement characteristic 92 shown by a thick solid line.

  However, according to the motor output requirement characteristic 92 shown in FIG. 11, the rating of the wiper motor has to be increased, which may increase the size of the wiper device and increase the manufacturing cost. In addition, when the rating of the wiper motor is determined according to the motor output requirement characteristic 92, the excess region 98 which is a region of the motor rotational speed and torque which is not required in the high speed operation mode or the low speed operation mode is accompanied, and the characteristic of the wiper motor is sufficiently obtained. There was a problem of not using it.

  As a factor that hinders the increase in the rotation speed of the motor, there is a counter electromotive force generated in the armature of the motor as the motor rotates. The counter electromotive force has a polarity opposite to that of the voltage applied to the motor, and inhibits the current of the armature of the motor. When the counter electromotive force is generated in the armature, even if the voltage applied to the motor is increased, the rotational speed of the motor cannot be increased.

  Patent Document 1 discloses a brushless motor and a wiper device that control the voltage applied to the coil of the stator, suppress the generation of back electromotive force by a field weakening that weakens the magnetic field of the stator, and improve the rotation speed of the motor. Has been.

JP 2013-198188 A

  However, the brushless motor and the wiper device described in Patent Document 1 have a problem in that although the rotational speed of the motor is improved by weakening the magnetic field of the stator, the motor torque 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 the rotation speed of a wiper motor while ensuring a necessary torque.

In order to solve the above-mentioned problem, the wiper control device according to claim 1 is connected to a wiper arm to which a wiper blade for wiping windshield glass is attached, a rotor composed of permanent magnets, and a generated rotating magnetic field A coil for rotating the rotor, and a magnetic field detection unit for detecting a magnetic field indicating the position of the rotor and outputting a signal corresponding to the magnetic field, and rotating the rotor to rotate the lower and upper inverted positions of the windshield glass A wiper motor that reciprocates the wiper arm between the wiper blade, a wiper switch that outputs a command to change the speed of the reciprocating operation of the wiper blade, and a reduction mechanism that decelerates the speed of the wiper motor, and is attached to the output shaft The sensor magnet attached to the center of the bottom surface of the worm wheel and the speed reduction mechanism are accommodated. Based on a rotation angle detection unit including a rotation angle sensor disposed opposite to the sensor magnet on a substrate disposed immediately below the speed reduction mechanism in the hooding, and a signal output by the rotation angle detection unit The rotational speed of the wiper motor is determined in accordance with the position of the wiper blade on the windshield glass calculated from the rotation angle of the output shaft determined and the command output by the wiper switch, and the magnetic field detector The phase of the voltage that changes according to the position of the rotor determined based on the output signal is calculated, and the wiper switch outputs the phase of the calculated voltage so that the wiper motor rotates at the determined rotational speed. A determining unit that determines the phase of the voltage applied to the coil by changing the angle corresponding to the electrical angle corresponding to the speed of the command;
A drive circuit that applies a voltage having a phase determined by the determination unit to the coil.

  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. Yes.

  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 retarded with respect to the phase of the voltage applied to the coil. Therefore, the torque and rotational speed of the motor can be improved by advancing the phase of the voltage applied to the motor coil so that the phase of the coil current approaches the phase corresponding to the position of the rotor. Therefore, according to this wiper control device, it is possible to improve the rotational speed of the wiper motor while ensuring the necessary torque.

  The wiper control device according to claim 2 is the wiper control device according to claim 1, wherein the determination unit receives an instruction to change the reciprocating speed of the wiper blade to a high speed from the wiper switch. Is an angle corresponding to a predetermined electrical angle determined in advance based on a change in the phase of the current of the coil and a change in the phase of the induced voltage generated in the coil. The phase advanced in step S3 is defined as the phase of the voltage applied to the coil.

  According to this wiper control device, the rotational speed of the wiper motor can be improved while ensuring the necessary torque during high speed operation by advancing the phase of the voltage applied to the motor coil.

  According to a fourth aspect of the present invention, in the wiper control device according to the second or third aspect, the determination unit receives an instruction to change the speed of the reciprocating operation of the wiper blade from the wiper switch 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, the wiper motor can be rotated at a rotation speed and torque suitable for low speed operation 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. .

  A wiper control device according to a fifth aspect is the wiper control device according to the fourth aspect, wherein the rotation speed of the wiper motor in each case where the reciprocating speed of the wiper blade is low speed and high speed is determined by the wiper blade. The storage unit stores a low speed and a high speed defined according to the position on the windshield glass, and the determination unit changes the speed of the reciprocating operation of the wiper blade from the wiper switch to a low speed. When the command to input is input, the rotational speed of the wiper motor is determined according to the calculated position of the wiper blade based on the low speed, and the wiper motor rotates 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 wiper switch When a command to change the reciprocating speed of the wiper blade to a high speed is input, the rotational speed of the wiper motor corresponding to the calculated position of the wiper blade is determined based on the high speed, and the determined rotation A phase obtained by advancing a phase that changes according to the calculated rotor position by an angle corresponding to a predetermined electrical angle so that the wiper motor rotates at a speed is set 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 that determines the rotational speed of the wiper motor according to the position of the wiper blade in advance. it can.

  Furthermore, according to this wiper control device, the rotational speed of the wiper motor can be improved while ensuring the necessary torque during high speed operation by advancing the phase of the voltage applied to the coil of the wiper motor by a predetermined electrical angle. Can do.

It is the schematic which shows the structure of the wiper apparatus containing the wiper control apparatus which concerns on embodiment of this invention. It is the schematic which shows the position of the sensor of the wiper motor which concerns on embodiment of this invention. It is sectional drawing which shows the cross section which cut | disconnected the wiper motor along the AA line shown by FIG. It is a block diagram which shows the outline of an example of a structure of the wiper control apparatus which concerns on embodiment of this invention. It is a figure which shows an example of the outline of the analog waveform of the voltage which the Hall sensor with which a wiper motor with which each wiper motor is equipped outputs is obtained, and the outline of the digital waveform which obtained the analog waveform via circuits, such as a comparator. In the wiper control apparatus which concerns on embodiment of this invention, it is the schematic which showed the aspect of the applied voltage applied to a coil, the induced voltage produced in the coil by rotation of the rotor, and the winding current which flows into a coil, (A) Is the case of no advance angle control in which a voltage is applied to the coil according to the position of the rotor, and (B) is the case of the advance angle control in which the timing of applying the voltage to the coil is earlier than the position of the rotor. In the wiper device including the wiper control device according to the embodiment of the present invention, the wiper blade reciprocates between the lower inversion position and the upper inversion position on the windshield glass according to the position of the wiper blade. It is the schematic which shows an example of the speed map which prescribed | regulated the rotational speed of the wiper motor. Schematic which shows an example of the change of the voltage (Duty) applied to the wiper motor in the wiper apparatus provided with the wiper control device according to the embodiment of the present invention when the wiper blade operates from the lower reverse position to the upper reverse position. It is. It is the schematic which showed an example of the characteristic of the output of the wiper motor enabled by the wiper control apparatus which concerns on embodiment of this invention. It is a flowchart which shows an example of the control in the wiper control apparatus which concerns on embodiment of this invention. It is the schematic which showed an example of the characteristic requested | required of a wiper motor in a high-speed operation mode and a low-speed operation mode.

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

  The wipers 14 and 16 are constituted by wiper arms 24 and 26 and wiper blades 28 and 30, respectively. The base end portions 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 the distal end portions 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 a circumferential direction of a rotor composed of permanent magnets. The wiper motor 18 has an output shaft 32 that can rotate forward and reverse via a speed reduction mechanism 52 mainly composed of a worm gear. The link mechanism 20 includes a crank arm 34, a first link rod 36, and a pair of pivots. The levers 38 and 40, a pair of pivot shafts 42 and 44, and a second link rod 46 are provided.

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

  The pivot shafts 42 and 44 are operatively 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 via the pivot shafts 42 and 44. The wiper arms 24 and 26 are fixed respectively.

  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 backward 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 wiper blades 28 and 30 are reciprocated between the lower inversion position P2 and the upper inversion position P1 on the windshield glass 12 as the wiper arms 24 and 26 are reciprocated. Although the value of θ1 can take various values depending on the configuration of the link mechanism of the wiper control device, etc., in this 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 is a linear configuration.

  The storage position P3 is provided below the lower inversion position P2. The wiper blades 28 and 30 are moved to the storage position P3 by rotating the output shaft 32 by θ2 from the state where the wiper blades 28 and 30 are in the lower inversion position P2. The value of θ2 can take various values depending on the configuration of the link mechanism of the wiper device, etc., but in this embodiment, it is 10 ° as an example.

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

  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 includes, for example, a rotation angle sensor 54 that detects the rotation speed and rotation angle of the output shaft 32 of the wiper motor 18, and PWM (Pulse Width Modulation) control of the current for operating the wiper motor 18. And a hall sensor 72 for detecting the position of the rotor of the wiper motor 18.

  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 with 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 rotation angle of the output shaft 32 are not the same as the rotation speed and 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 inseparably configured, hereinafter, the rotation speed and rotation angle of the output shaft 32 are regarded as the rotation speed and rotation angle of the wiper motor 18. .

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

  The wiper control device 10 can calculate the position 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 depends on the position. A microcomputer 58 that controls the drive circuit 56 so as to change is provided. The wiper control device 10 has a memory 48 that stores data and programs used for controlling the drive circuit 56, and a wiper switch 50 is connected to the microcomputer 58 of the wiper control device 10. The memory 48 is 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 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 for turning on or off the electric power supplied to the wiper motor 18 from a vehicle battery as a power source. The wiper switch 50 includes a low-speed operation mode selection position for operating the wiper blades 28 and 30 at a low speed, a high-speed operation mode selection position for operating at a high speed, an intermittent operation mode selection position for intermittent operation at a constant period, and storage (stop). The mode selection position can be switched. In addition, a rotation speed command signal corresponding to the selected position in each mode is output to the microcomputer 58.

  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 using the control corresponding to the output signal from the wiper switch 50.

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

  A worm 52A is formed at the end of the 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 the 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 facing 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 formed in a spiral shape along the axial direction of the rotor shaft 88A. Further, the worm wheel 52B is formed in a disc shape, and a spur tooth groove is formed along the circumferential direction thereof. The helical leaf groove of the worm 52A and the tooth groove of the worm wheel 52B mesh with each other, so that the rotation of the rotor 88 can be decelerated 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, the microcomputer 58, elements constituting the drive circuit 56, and the like are mounted. Further, in the portion of the substrate 90 facing the sensor magnet 70 provided at the end of the output shaft 32, a signal indicating the change in the magnetic field is detected by detecting the magnetic field of the sensor magnet 70 that changes according to the rotation of the output shaft 32. Is mounted.

  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 a three-phase six-pole DC brushless motor as an example.

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

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

  Information on the digital waveforms 104U, 104V, 104W and the 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 rotational speed of the wiper motor 18 (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 estimation unit 64, and based on the calculated phase and the rotation speed of the rotor 88 indicated by the wiper switch 50. To determine the drive duty value. The energization control unit 68 performs PWM control that generates a PWM signal that is a pulse signal corresponding to the drive duty value and outputs 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 switching element. Three N-channel field effect transistors (MOSFETs) 76U, 76V, 76W (hereinafter referred to as “FETs 76U, 76V, 76W”) as lower-stage switching elements are provided. The FETs 74U, 74V, and 74W and the FETs 76U, 76V, and 76W are collectively referred to as “FET74” and “FET76” when they do not need to be distinguished from each other, and “U” when they need to be distinguished from each other. , “V”, “W” are attached with symbols.

  Among 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 FET 76W. The drain is connected to the terminal of the coil 86W.

  The gates of the FET 74 and FET 76 are connected to the energization control unit 68, and a PWM signal is input. The FET 74 and FET 76 are turned on when an H level PWM signal is input to the gate, and current flows from the drain to the source. Further, 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.

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

  FIG. 6 shows aspects of the applied voltage 112 applied to the coil 86, the induced voltage 114 generated in the coil 86 due to the rotation of the rotor 88, and the winding current 116 flowing in the coil 86. FIG. In the case of no advance angle control in which a voltage is applied to the coil 86 in accordance with the position of the rotor 88 calculated by the motor position estimation unit 64, (B) is directed to the coil 86 from the position of the rotor 88 calculated by the motor position estimation unit 64. This is the case with advance angle control in which the voltage application timing is advanced. FIG. 6 is applicable to any of the U phase, V phase, and W phase.

  In general, in a brushless DC motor, the voltage applied to the wiper motor 18 is controlled without the advance angle control, which generates a voltage having a phase corresponding to the position of the rotor 88 calculated based on the signal output from the Hall sensor 72. Also in this 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 angle control.

  6A and 6B, the phase of the induced voltage 114 corresponds to the position of the rotor 88. That is, the peak 114 </ b> A of the induced voltage 114 indicates when the S-pole or N-pole magnet constituting the rotor 88 is 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 shows the peak 114A, is maximized as shown by the peak 116A, the interaction between the rotor 88 and the coil 86 by the magnetic field becomes stronger, and as a result. As a result, high-efficiency control that achieves both high-speed rotation and torque of the wiper motor 18 becomes possible.

  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, by causing the phase of the applied voltage 112 to advance (advance) by a predetermined electrical angle α from the phase corresponding to the position of the rotor 88, the induced voltage 114 and the winding The phase 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 and the induced voltage 114 of the coil 86, and in the present embodiment, it is 60 to 90 degrees as an example.

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

  FIG. 7 shows the rotation of the wiper motor 18 according to the position of the wiper blades 28 and 30 when the wiper blades 28 and 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 speed. In order to realize the high speed operation mode and the low speed operation mode, the high speed operation mode speed map 122 and the 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 speed of the wiper motor 18 is both zero at the lower reverse position P2 and the upper reverse position P1. Further, the high-speed operation mode speed map 122 and the low-speed operation mode speed map 124 indicate increase / decrease in the rotation speed of the wiper motor 18 such that the rotation speed of the wiper motor 18 becomes maximum at a substantially middle point between the lower inversion position P2 and the upper inversion position P1. Are coincident 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 the voltage applied to the wiper motor 18 when the wiper blades 28 and 30 are operated from the lower inversion position P2 to the upper inversion position P1 in the wiper apparatus 100 including the wiper control apparatus 10 according to the present embodiment. It is the schematic which shows an example of a change of (Duty). The low-speed operation voltage 134 is obtained when the low-speed operation mode speed map 124 shown in FIG. 7 is used and the advance angle control is not performed. The high-speed operation voltage 132 is obtained by using the high-speed operation mode speed map 122 shown in FIG. This is the case of using and controlling the advance angle. As a result of increasing 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 showing an example of output characteristics of the wiper motor 18 that can be performed by the wiper control device 10 according to the present embodiment. Without advance angle control, even the wiper motor 18 showing the rotational speed and torque indicated by the low speed operation mode output characteristic 144 can be rotated at the rotational speed and torque indicated by the high speed operation mode output characteristic 142 by the advance angle control. It becomes.

  FIG. 10 is a flowchart showing an example of control in the 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 timing control is performed to advance the timing of applying the wiper motor 18 voltage by the electrical angle α. If the determination in step 700 is negative, advance angle control is not performed in step 704. In addition, the timing which applies a voltage to the wiper motor 18 shall be calculated at any time according to the phase of the voltage calculated from the signal from the hall sensor 72 as mentioned 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 in the speed map corresponding to the position and the actual rotation speed of the wiper motor 18 are added. Rotational speed feedback is performed. The rotational speed feedback uses, for example, PI control (Proportional Integral Controller) or the like to add the actual rotational speed of the wiper motor 18 calculated based on the signal from the hall sensor 72 to the rotational 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 as to obtain a rotational speed based on the rotational speed feedback, and the process returns. Further, in step 708, in the case of advance angle control, 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 rotation speed of the wiper motor while ensuring the necessary torque by the advance angle control that advances the timing of applying the wiper motor 18 voltage by the electrical angle α. It becomes.

  In the present embodiment, the advance angle control is performed when the wiper apparatus 100 is in the high speed operation mode. However, the advance angle control may be performed even 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 by an electrical angle corresponding to the low speed operation mode, which is different from that in 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 ... Deceleration 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 ... Energization 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 area, 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 132, high speed operation voltage, 134, low speed operation voltage, 142, high speed operation mode output characteristics, 144, low speed operation mode output characteristics, P1, upper reverse position, P2, lower reverse position, P3, storage position , Α ... electrical angle, θ1 ... rotation angle

Claims (5)

It is connected to a wiper arm to which a wiper blade for wiping the windshield glass is attached, detects a rotor composed of permanent magnets, a coil for rotating the rotor with the generated rotating magnetic field, and a magnetic field indicating the position of the rotor. 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 reversal position and an upper reversal position of the windshield glass by rotation of the rotor;
A wiper switch that outputs a command to change the reciprocating speed of the wiper blade;
In addition to constituting a speed reduction mechanism for reducing the speed of the wiper motor, a sensor magnet attached to the center of the bottom surface of a worm wheel attached to the output shaft, and a housing for housing the speed reduction mechanism, are disposed directly below the speed reduction mechanism. A rotation angle detection unit including a rotation angle sensor disposed on the substrate facing the sensor magnet;
The rotation of the wiper motor according to the position of the wiper blade on the windshield glass calculated from the rotation angle of the output shaft determined based on the signal output from the rotation angle detector and the command output from the wiper switch In addition to determining the speed, the phase of the voltage that changes according to the position of the rotor determined based on the signal output from the magnetic field detector is calculated, and the calculation is performed so that the wiper motor rotates at the determined rotational speed. Determining a phase of the voltage to be applied to the coil by changing the phase of the voltage at an angle corresponding to an electrical angle corresponding to the speed of the command output by the wiper switch;
A drive circuit for applying a voltage having a phase determined by the determination unit to the coil;
Wiper control device having   When the command for changing the speed of the reciprocating operation of the wiper blade to a high speed is input from the wiper switch, the determining unit sets the phase of the voltage that changes according to the calculated rotor position to the phase of the current of the coil. 2. The phase of the voltage applied to the coil is defined as a phase advanced by an angle corresponding to a predetermined electrical angle determined based on a change in phase and a phase change in induced voltage generated in the coil. Wiper control device.   The wiper control device according to claim 2, wherein the predetermined electrical angle is 60 to 90 degrees.   When the 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 determines a voltage phase to be applied to the coil that changes in phase according to the position of the rotor. The wiper control device according to claim 2 or 3, wherein the phase is a phase. The speed for low speed and the speed for high speed that specify the rotational speed of the wiper motor in accordance with the position of the wiper blade on the windshield glass when the reciprocating speed of the wiper blade is low speed and high speed are stored. Further comprising a storage unit
When the command to change the speed of the reciprocating operation of the wiper blade to a low speed is input from the wiper switch, the determination unit is configured to perform the wiper motor according to the calculated position of the wiper blade based on the low speed. And the phase that changes according to the calculated rotor position so that the wiper motor rotates at the determined rotational speed is set as the phase of the voltage applied to the coil, and the wiper blade switches from the wiper switch to the wiper blade. When a command for changing the reciprocating speed of the motor to a high speed is input, the rotational speed of the wiper motor corresponding to the calculated position of the wiper blade is determined based on the high speed, and the determined rotational speed The phase that changes in accordance with the calculated rotor position 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.