JP6239378B2 - WIPER DEVICE AND WIPER DEVICE CONTROL METHOD - Google Patents

Description

The present invention relates to a wiper device including a detection sensor for detecting a phase in a rotation direction of a rotor, and a method for controlling the wiper device.

  An example of a conventional motor device is described in Patent Document 1. The motor device described in Patent Document 1 includes a brushless motor, an inverter circuit, a control circuit, a speed control calculation unit, and the like. The brushless motor has a rotor to which a permanent magnet and a sensor magnet are attached, and a stator provided on the outer peripheral side of the rotor. The stator has a core in which steel plates or the like are laminated, and three coils wound around the core, that is, three coils corresponding to the U phase, the V phase, and the W phase.

  The inverter circuit connects and disconnects the three coils and the power source. The inverter circuit includes a positive switching element and a negative switching element corresponding to the U phase, the V phase, and the W phase, respectively. And. Further, the control circuit turns these switching elements on and off separately.

  Furthermore, three detection sensors that output signals based on the strength of the magnetic field formed by the sensor magnet are provided corresponding to the U phase, the V phase, and the W phase. The three detection sensors are arranged outside the sensor magnet at intervals of a mechanical angle of 120 °. Further, the speed control calculation unit receives a signal output from the detection sensor and controls on / off of the switching element of the inverter circuit.

  The motor device described in Patent Literature 1 is controlled by turning on / off a plurality of switching elements, supplying current to three coils at a predetermined timing, and rotating magnetic fields are formed by the three coils. The child rotates. The speed control calculation unit detects the rotation phase of the rotor based on a signal output from one of the three detection sensors, and determines the rotation phase based on the detected rotation phase. The on / off timing of the plurality of switching elements is controlled.

  Therefore, even if there is an error in the mounting position of the other two detection sensors with respect to one predetermined detection sensor, the three coils can be energized at the ideal energization timing, and the rotation of the rotor It is said that the number can be controlled appropriately.

JP 2003-47277 A

  In the brushless motor described in Patent Document 1, it is difficult to say that the signals of the three detection sensors are effectively used, and there is still room for improvement.

An object of the present invention is to provide a wiper device and a wiper device control method capable of effectively using signals from a plurality of detection sensors for detecting a rotational phase of a rotor.

A wiper device of the present invention is a wiper device including a wiper blade for wiping a windshield of a vehicle, a wiper arm to which the wiper blade is attached, and a motor device for driving the wiper arm , the motor device being A brushless motor for driving the wiper arm; a driving device for controlling the brushless motor; a control board provided with the driving device; and a gear case containing the driving device and the control board; Includes a stator having a plurality of coils to which an electric current is supplied, and a rotor that is rotated by a rotating magnetic field formed by the stator and has a worm formed thereon, and the worm has the worm And a pivot shaft that rotates integrally with the worm wheel. A plurality of detection sensors that are provided in different phases in the rotation direction of the rotor and that generate an output signal by detecting the phase in the rotation direction of the rotor are attached to the control board, and the drive device An inverter circuit having a plurality of switching elements for controlling energization to the coil and connecting or blocking a current path to the coil, and an output signal of any one of the plurality of detection sensors And a signal correction unit that corrects output signals of other detection sensors, and an element control unit that controls the plurality of switching elements. The element control unit includes the reference signal and the corrected signal. By energizing the plurality of coils at a first timing by controlling the plurality of switching elements based on an output signal, the rotation is performed. By controlling the plurality of switching elements based on the reference signal and the corrected output signal, and by a predetermined electrical angle from the first timing. The second energization control for energizing the plurality of coils to control the output of the rotor from the advanced second timing is performed by switching .

The wiper apparatus control method of the present invention includes a step of correcting an output signal of another detection sensor using an output signal of any one of the plurality of detection sensors as a reference signal, the reference signal, and the A first energization control for controlling energization of the rotor by starting energization at the first timing by controlling the plurality of switching elements based on the corrected output signal; or The plurality of coils from a second timing advanced by a predetermined electrical angle from the first timing by controlling the plurality of switching elements based on the reference signal and the corrected output signal. It is energized to have a, and executing switching the second energization control, which controls the output of the rotor.

According to the wiper device and the wiper device control method of the present invention, based on the signal of one detection sensor, the signals of the other detection sensors are corrected and the rotational phase of the rotor is detected by the plurality of detection sensors. The signals of a plurality of detection sensors can be used effectively.

It is a schematic diagram which shows the example which used the motor apparatus of this invention for the drive of the wiper apparatus of a vehicle. It is a typical top view which shows the motor apparatus of this invention. It is a typical side view showing a motor device of the present invention. It is sectional drawing of the brushless motor used for the motor apparatus of this invention. It is a conceptual diagram which shows the armature in the brushless motor of FIG. It is a block diagram which shows the control system of the motor apparatus of this invention. It is a time chart which shows the drive pattern of the 1st electricity supply control performed with the motor apparatus of this invention. It is a time chart which shows the drive pattern of the 1st electricity supply control performed with the motor apparatus of this invention. It is a time chart which shows the drive pattern of the 2nd electricity supply control performed with the motor apparatus of this invention. It is a figure which shows the output characteristic of the motor apparatus of this invention. It is a time chart which shows the drive pattern of the 3rd electricity supply control performed with the motor apparatus of this invention. It is a time chart which shows the waveform of the signal of the detection sensor in the motor apparatus of this invention. It is a time chart which shows the waveform of the signal of the detection sensor in the motor apparatus of this invention. It is a time chart which shows the waveform of the signal of the detection sensor in the motor apparatus of this invention. It is a time chart which shows the waveform of the signal of the detection sensor in the motor apparatus of this invention. It is a flowchart which shows the example of control which can be performed with the motor apparatus of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present embodiment is an example in which a motor device is used in a vehicle. The vehicle 10 shown in FIG. 1 has a windshield 11. The vehicle 10 includes a first wiper device 12 and a second wiper device 13 that wipe the windshield 11. The first wiper device 12 and the second wiper device 13 are arranged at different positions in the width direction of the vehicle 10. Since the first wiper device 12 and the second wiper device 13 have a substantially symmetrical structure, the first wiper device 12 will be described below for convenience. The first wiper device 12 includes a wiper arm 15 that swings about a pivot shaft 14, and a wiper blade 16 that is attached to the wiper arm 15. The first wiper device 12 has a motor device 17 that drives the wiper arm 15. The motor device 17 includes a brushless motor 18 and a speed reduction mechanism 19 that transmits the power of the brushless motor 18 to the pivot shaft 14.

  The brushless motor 18 is configured as shown in FIGS. The brushless motor 18 in this embodiment has a bottomed cylindrical motor case 20, and an armature 21 as a stator is provided on the inner periphery of the motor case 20. The armature 21 includes a stator core 22 and armature coils V1, V2, U1, U2, W1, and W2 wound around the stator core 22. The stator core 22 is formed by stacking conductive metal plates, and a plurality of, specifically, six teeth 23 are provided on the inner periphery of the stator core 22 at intervals in the circumferential direction. The six teeth 23 are arranged at a mechanical angle of 60 °. The armature coils V1, V2, U1, U2, W1, and W2 are separately wound around the six teeth 23.

  The armature coils V1, V2 correspond to the V phase, the armature coils U1, U2 correspond to the U phase, and the armature coils W1, W2 correspond to the W phase. In FIG. 4, the armature coil U1, the armature coil V1, the armature coil W1, the armature coil U2, the armature coil V2, and the armature coil W2 are provided in the order of the armature 21 in the clockwise direction. . The armature coil U1 and the armature coil U2 are in a positional relationship of a mechanical angle of 180 °, and the armature coil V1 and the armature coil V2 are in a positional relationship of a mechanical angle of 180 °, and the armature coil W1 and the electric machine The slave coil W2 is in a positional relationship with a mechanical angle of 180 °.

  The configuration of the armature 21 will be described with reference to FIGS. The armature coil U1 and the armature coil U2 are connected in series, the armature coil V1 and the armature coil V2 are connected in series, and the armature coil W1 and the armature coil W2 are connected in series. Further, the end portion Ua of the armature coil U1 and the end portion Ub of the armature coil W2 are connected by a terminal 24. Further, the end portion Vb of the armature coil U2 and the end portion Va of the armature coil V1 are connected by a terminal 25. Further, the end portion Wa of the armature coil W1 and the end portion Wb of the armature coil V2 are connected by a terminal 26. Thus, the brushless motor 18 connects the six armature coils V1, V2, U1, U2, W1, and W2 by delta connection.

  On the other hand, the brushless motor 18 has a rotor 27, and the rotor 27 is provided inside the armature 21. The brushless motor 18 has an inner rotor type structure in which a rotor 27 is disposed inside an armature 21 as a stator. The rotor 27 includes a rotor shaft 28 and four-pole permanent magnets 29N and 29S fixed to the outer periphery of the rotor shaft 28 via a rotor core 30. The polarities of the two permanent magnets 29N are N poles, the polarities of the two permanent magnets 29S are S poles, and the permanent magnets 29N and the permanent magnets 29S are alternately arranged along the circumferential direction of the rotor shaft 28. Has been placed. The brushless motor 18 has a 4-pole 6-slot structure with 4 permanent magnets and 6 armature coils.

  Thus, the brushless motor 18 has an SPM (Surface Permanent Magnet) structure. In the SPM structure, permanent magnets 29 </ b> N and 29 </ b> S are fixed to the outer peripheral surface of the rotor core 30. The rotor core 30 is formed of an iron-based magnetic material. The rotor shaft 28 is rotatably supported by a plurality of, that is, two bearings 49.

  On the other hand, the motor device 17 includes a gear case 31 that houses the speed reduction mechanism 19, and the gear case 31 and the motor case 20 are fixed by a fastening member (not shown). A part of the rotor shaft 28 in the length direction is disposed inside the motor case 20, and the remaining part is disposed in the gear case 31. A worm 32 is formed on the outer periphery of a portion of the rotor shaft 28 disposed in the gear case 31. A worm wheel 33 is provided in the gear case 31. A gear 33a is formed on the outer periphery of the worm wheel 33, and the gear 33a and the worm 32 are engaged with each other.

  The pivot shaft 14 is disposed concentrically with the worm wheel 33, and the pivot shaft 14 rotates integrally with the worm wheel 33. The worm 32 and the gear 33a are the speed reduction mechanism 19 in the present embodiment. The speed reduction mechanism 19 is a mechanism that, when transmitting the power of the rotor 27 to the pivot shaft 14, makes the rotation speed (output rotation speed) of the pivot shaft 14 lower than the rotation speed (input rotation speed) of the rotor 27. is there. The rotation speed in the present embodiment is the rotation speed per unit time and is synonymous with the rotation speed.

  Further, in FIG. 3, a shaft hole (not shown) is provided in the upper part of the gear case 31. The end of the pivot shaft 14 opposite to the end to which the worm wheel 33 is fixed is exposed to the outside through the shaft hole of the gear case 31. The wiper arm 15 is connected to a portion of the pivot shaft 14 exposed to the outside of the gear case 31.

  On the other hand, a sensor magnet 34 is attached to a portion of the rotor shaft 28 disposed in the gear case 31. The sensor magnet 34 rotates integrally with the rotor shaft 28. The sensor magnet 34 has a cylindrical shape, and the sensor magnet 34 is magnetized so that N poles and S poles are alternately arranged along the circumferential direction of the rotor shaft 28.

  An opening is provided in a portion of the gear case 31 opposite to the shaft hole. The opening is formed to insert the worm wheel 33, the pivot shaft 14 and the like into the gear case 31. An under cover 35 that closes the opening is provided. The under cover 35 has a tray shape, and a control board 36 is provided in a space surrounded by the under cover 35 and the gear case 31.

  The control board 36 is provided with a drive device 37 for controlling the brushless motor 18 as shown in FIG. The drive device 37 has an inverter circuit 38 that controls energization of the six armature coils V1, V2, U1, U2, W1, and W2. The inverter circuit 38 is connected to the terminals 24, 25 and 26. In addition, the under cover 35 is provided with a connector 39. By connecting a power cable connected to the external power source 40 to the connector 39, the external power source 40 and the inverter circuit 38 are connected. The external power supply 40 includes a battery or a capacitor mounted on the vehicle 10.

  Further, the inverter circuit 38 has a plurality of, that is, six switching elements for separately connecting or blocking the current supply paths from the external power supply 40 to the six armature coils V1, V2, U1, U2, W1, W2. Elements 38a to 38f are provided. The six switching elements 38a to 38f are configured by semiconductor elements such as FETs, for example. More specifically, the switching element 38a on the positive electrode side corresponding to the U phase and connected to the positive electrode of the external power supply 40, and the switching element 38a on the negative electrode side corresponding to the U phase and connected to the negative electrode side of the external power supply 40. 38d.

  Furthermore, a positive side switching element 38b corresponding to the V phase and connected to the positive electrode of the external power supply 40, and a negative side switching element 38e corresponding to the V phase and connected to the negative side of the external power supply 40 are provided. Is provided. Further, a positive side switching element 38c corresponding to the W phase and connected to the positive side of the external power supply 40, and a negative side switching element 38f corresponding to the W phase and connected to the negative side of the external power supply 40 are provided. Is provided.

  Here, the switching elements 38a, 38b, and 38c are connected in parallel to each other, and the switching elements 38d, 38e, and 38f are connected in parallel to each other. The switching element 38a and the switching element 38d are connected in series, the switching element 38b and the switching element 38e are connected in series, and the switching element 38c and the switching element 38f are connected in series. Further, the source of the switching element 38 a and the drain of the switching element 38 d are connected to the terminal 24. Further, the source of the switching element 38 b and the drain of the switching element 38 e are connected to the terminal 25. Further, the source of the switching element 38 c and the drain of the switching element 38 f are connected to the terminal 26.

  Furthermore, the drive device 37 includes a control circuit 50 that controls the six switching elements 38a to 38f. The control circuit 50 is a known microcomputer provided with a CPU, RAM, ROM and the like. Further, the drive device 37 has a PWM signal generation circuit 51, and a signal from the PWM signal generation circuit 51 is input to the control circuit 50. The control circuit 50 outputs drive signals for separately controlling the six switching elements 38a to 38f, and a PWM signal is superimposed on the drive signals. That is, the six switching elements 38a to 38f are driven by PWM control, and are intermittently turned on / off in each energization period.

  The current supplied to the six armature coils V1, V2, U1, U2, W1, and W2 by controlling the rate at which the six switching elements 38a to 38f are individually turned on, that is, the duty ratio. The value is controlled. That is, it is possible to increase / decrease the energizing section fed to the six armature coils V1, V2, U1, U2, W1, W2 between 0% and 100% with respect to all the sections that can be energized. Here, when the waveforms energized in the armature coils V1, V2, U1, U2, W1, and W2 are expressed in electrical angles, the “section” means an electrical angle.

  Furthermore, the brushless motor 18 in the present embodiment switches on and off of the switching element 38a to reverse the direction of energization to the six armature coils V1, V2, U1, U2, W1, and W2. The rotor 27 can be rotated forward and backward.

  The control board 36 is disposed along a plane direction perpendicular to the first axis A1 of the pivot shaft 14. The first axis A1 is the center when the pivot shaft 14 rotates. Three detection sensors 41, 42, and 43 are attached to the control board 36. The three detection sensors 41, 42, and 43 are all Hall ICs, and the three detection sensors 41, 42, and 43 are fixed to the control board 36 without contact with the sensor magnet 34. In this embodiment, the detection sensor 41 outputs a switching signal corresponding to the W phase, the detection sensor 42 outputs a switching signal corresponding to the V phase, and the detection sensor 43 outputs a switching signal corresponding to the U phase. The three detection sensors 41, 42, 43 are arranged in a direction intersecting the second axis B1 of the rotor shaft 28 as shown in FIG. The second axis B1 is the center when the rotor shaft 28 rotates.

  In the direction along the second axis B1, the arrangement range of the three detection sensors 41, 42, and 43 and the arrangement range of the sensor magnet 34 overlap at least partially. Assuming that the control board 36 is horizontally disposed, as shown in FIG. 3, the detection sensor 42 corresponding to the V phase is disposed immediately below the second axis B1. The three detection sensors 41, 42, 43 are arranged at equal intervals in the direction intersecting the second axis B1. The detection sensor 42 is disposed between the detection sensor 41 and the detection sensor 43.

  The three detection sensors 41, 42, and 43 are switched when the rotor 27 rotates and the magnetic pole of the sensor magnet 34 moves, and the three detection sensors 41, 42, and 43 are each switched signals (output signals). Are generated separately. The control circuit 50 can detect the rotation phase and the number of rotations of the rotor 27 based on the switching signals of the three detection sensors 41, 42, and 43. The rotation phase of the rotor 27 is an angle or a position in the rotation direction with reference to a predetermined position. The control circuit 50 also has a function of estimating the operation load of the wiper arm 50 based on the switching signals of the three detection sensors 41, 42, and 43.

  Further, a wiper switch 44 is provided in the vehicle 10. When the driver operates the wiper switch 44 to select the low speed mode or the high speed mode, an operation signal of the wiper switch 44 is input to the control circuit 50. . Further, a vehicle speed sensor 45 that detects the traveling speed of the vehicle 10 is provided, and a detection signal of the vehicle speed sensor 45 is input to the control circuit 50.

  Further, the control circuit 50 controls the output of the rotor 27 of the brushless motor 18, that is, the energization pattern for the six armature coils V 1, V 2, U 1, U 2, W 1, W 2 in order to control the rotation speed and torque. Data etc. are memorized. More specifically, the control circuit 50 includes switching elements 38a to 38f of the inverter circuit 38 based on various conditions such as an operation signal of the wiper switch 44, a detection signal of the vehicle speed sensor 45, and an operation load of the wiper arm 15. Data for controlling on / off timing, duration time for which the switching element 38a is turned on, and the like are stored in advance.

  Specifically, the operating load of the wiper arm 15 can be estimated from the switching signals of the detection sensors 41, 42, and 43. For example, when the high speed mode is selected, the control circuit 50 obtains the target rotational speed of the rotor 27 that should achieve the target wiping speed of the wiper arm 15 in the high speed mode, and the actual rotational speed of the rotor 27 is the target rotational speed. Energization control is performed so that The control circuit 50 can estimate that the operating resistance of the wiper arm 15, that is, the operating load of the wiper arm 15 is increased due to snow or the like when the actual rotational speed of the rotor 27 does not reach the target rotational speed.

  Moreover, since the wind pressure which the wiper arm 15 receives will change if vehicle speeds differ, the operating load of the wiper arm 15 differs. Further, when the inclination angle of the windshield 11 is different, the wind pressure received by the wiper arm 15 is changed, so that the operation load of the wiper arm 15 is different. The inclination angle of the front window glass 11 is represented by the inclination angle on the acute angle side of the front window glass 11 with respect to the horizontal plane. Furthermore, when the length of the wiper blade 16 is different, the operating load of the wiper arm 15 is different.

  The gear case 31 is provided with a plurality of attachment portions 46, for example, three locations, and the attachment portions 46 are each provided with a shaft hole. In addition, a buffer material 47 is attached to each of the shaft holes of the attachment portion 46. The buffer material 47 is a synthetic rubber formed in an annular shape, and a screw member is inserted into the hole 47 a of the buffer material 47 so that the motor device 17 is attached to the vehicle body 48.

  Next, control examples that can be executed by the motor device 17 in order to control the operations of the first wiper device 12 and the second wiper device 13 will be described. The control circuit 50 of the motor device 17 controls on / off of the plurality of switching elements 38 a according to conditions other than the operation signal of the wiper switch 44 or the operation signal of the wiper switch 44. The control circuit 50 detects the rotational phase of the rotor 27 based on the detection signals of the three detection sensors 41, 42, and 43, and performs energization control based on the rotational phase of the rotor 27. That is, the positive side switching elements 38a, 38b, 38c are turned on / off separately at a predetermined electrical angle, and the negative side switching elements 38d, 38e, 38f are turned on / off separately at a predetermined electrical angle. The armature coils U1, U2, V1, V2, W1, and W2 are switched to energize and phase current is commutated.

  When the above control is repeated, a rotating magnetic field is formed by the armature 21 and the rotor 27 rotates. The brushless motor 18 switches the switching elements 38a to 38f on and off, and reverses the direction of energization to the armature coils U1, U2, V1, V2, W1, and W2, thereby rotating the rotor 27 in the forward direction.・ Can be stopped and rotated in reverse. When the power of the rotor 27 is transmitted to the pivot shaft 14 via the speed reduction mechanism 19, the wiper arm 15 reciprocates within a predetermined angle range, and the windshield 11 is wiped by the wiper blade 16.

  In FIG. 1, the wiper arm 15 reciprocates between, for example, a lower inversion position D1 indicated by a solid line and an upper inversion position D2 indicated by a two-dot chain line. The upper inversion position D2 is a position farther than the lower inversion position D1 with respect to the vehicle body 48 to which the motor device 17 is attached. The location where the motor device 17 is attached is, for example, below the louver.

  The range in which the wiper arm 15 operates from the lower inversion position toward the upper inversion position D2 is the forward path, and the range in which the wiper arm 15 operates from the upper inversion position D2 toward the lower inversion position D1 is the return path. When the wiper arm 15 operates in the forward path, the rotor 27 shown in FIG. 3 rotates, for example, counterclockwise. When the wiper arm 15 operates in the backward path, the rotor 27 rotates in the clockwise direction. .

  As described above, the control circuit 50 controls the output of the rotor 27 by controlling the electrical angle timing at which the switching elements 38a to 38f are turned on or off, the electrical angle interval at which the switching elements 38a to 38f are turned on, and the like. Can be controlled. Electrical angle timing can also be referred to as electrical angle points. The brushless motor 18 has a characteristic that the rotational speed of the rotor 27 increases as the current value increases. Further, the brushless motor 18 has a characteristic that the torque of the rotor 27 decreases as the rotational speed of the rotor 27 increases.

  Further, the brushless motor 18 of the present embodiment performs the first energization control, the field weakening control as the second energization control, and the third energization control in controlling the output of the rotor 27, that is, the rotation speed and the torque. It can be switched and executed. The first energization control, the field weakening control, and the third energization control are switched according to various conditions such as the detection signal of the wiper switch 44, the detection signal of the vehicle speed sensor 45, the load of the wiper arm 15, and the operation direction of the wiper arm 15. In particular, the field weakening control can be executed when there is a request to increase the rotational speed of the rotor 27 compared to the first energization control. On the other hand, the third energization control can be executed when there is a request to increase the torque of the rotor 27 compared to the first energization control. That is, the third energization control is executed when the operating load of the wiper arm 15 is high, such as when there is snow on the windshield 11.

  The drive pattern of each switching element 38a-38f in 1st electricity supply control is demonstrated using the time chart of FIG.7 and FIG.8. FIG. 7 is a drive pattern of the switching elements 38a to 38f when the wiper arm 15 operates in the forward path, and FIG. 8 is a drive pattern of the switching elements 38a to 38f when the wiper arm 15 operates in the forward path.

  The drive patterns in FIGS. 7 and 8 are divided into six energization stages ST1 to ST6 starting from the rising edge or the falling edge of the switching signal output from each of the detection sensors 41, 42, 43. In this case, each energization stage is divided by a predetermined electrical angle (degree). In the example of FIGS. 7 and 8, each energization stage is divided by a range (section) having an electrical angle of 60 °. The rising edge of the switching signal means that the switching signal is switched from OFF to ON, and the falling edge of the switching signal means that the switching signal is switched from ON to OFF.

  In FIGS. 7 and 8, the switching signals of the detection sensors 41, 42, and 43 are set to an electrical angle of 180 ° in each of the ON sections, and the ON sections of the switching signals of the detection sensors 41, 42, and 43 are mutually switched. The electrical angle is set to be shifted by 60 °.

  FIG. 7 shows a drive pattern corresponding to the forward path of the wiper arm 15. The switching signal of the detection sensor 43 corresponding to the U phase is turned on at the timing of the electrical angle 0 ° and turned off at the timing of the electrical angle 180 °. Yes. While the switching signal of the detection sensor 43 corresponding to the U phase is turned on, the switching signal of the detection sensor 41 corresponding to the W phase is turned on at an electrical angle of 60 °. The switching signal of the detection sensor 43 corresponding to the U phase is turned off at the timing of the electrical angle of 240 °.

  Furthermore, while the switching signal of the detection sensor 41 corresponding to the W phase is turned on, the switching signal of the detection sensor 42 corresponding to the V phase is turned on at the timing of the electrical angle of 120 °. The switching signal of the detection sensor 42 corresponding to the V phase is turned off at an electrical angle of 300 °. The control circuit 50 controls the switching elements 38a to 38f as follows based on the switching signals of the detection sensors 41, 42, and 43.

  The switching element 38a on the positive side of the U phase is always turned on in the section of the electrical angle 120 ° from the timing of the electrical angle 30 ° to the timing of the electrical angle 150 °, and from the timing of the electrical angle 210 °, the electrical angle 330 °. In the section of the electrical angle of 120 ° over the timing, ON and OFF are alternately switched. In addition, the switching element 38d on the negative phase side of the U phase is alternately switched on and off in the section of the electrical angle of 120 ° from the timing of the electrical angle of 210 ° to the timing of the electrical angle of 330 °.

  In addition, the switching element 38b on the positive side of the V phase is alternately switched on and off in the section of the electrical angle of 120 ° from the timing of the electrical angle of 330 ° to the timing of the electrical angle of 90 °. Further, the switching element 38b on the positive side of the V phase is turned on at a timing of an electrical angle of 150 ° and is always turned on until it is turned off at a timing of an electrical angle of 270 °. On the other hand, the switching element 38e on the negative side of the V phase is alternately switched on and off in the section of the electrical angle of 120 ° from the timing of the electrical angle of 330 ° to the timing of the electrical angle of 90 °.

  Further, the switching element 38c on the positive side of the W phase is always turned on in the section of the electrical angle of 120 ° from the timing of the electrical angle of 270 ° to the timing of the electrical angle of 30 °. Further, the switching element 38c on the positive side of the W phase is alternately switched on and off in the section of the electrical angle of 120 ° from the timing of the electrical angle of 90 ° to the timing of the electrical angle of 210 °. Further, the switching element 38c on the negative side of the W phase is alternately switched on and off in the section of the electrical angle of 120 ° from the timing of the electrical angle of 90 ° to the timing of the electrical angle of 210 °.

  On the other hand, FIG. 8 shows a driving pattern corresponding to the return path of the wiper arm 15, and the switching signal of the detection sensor 43 corresponding to the U phase is turned on at the timing of the electrical angle of 0 ° and turned off at the timing of the electrical angle of 180 °. Has been. While the switching signal of the detection sensor 43 corresponding to the U phase is turned on, the switching signal of the detection sensor 42 corresponding to the V phase is turned on at the timing of the electrical angle of 60 °. The switching signal of the detection sensor 42 corresponding to the V phase is turned off at the timing of the electrical angle of 240 °.

  Furthermore, while the switching signal of the detection sensor 42 corresponding to the V phase is turned on, the switching signal of the detection sensor 41 corresponding to the W phase is turned on at the timing of the electrical angle of 120 °. The switching signal of the detection sensor 41 corresponding to the W phase is turned off at an electrical angle of 300 °. The control circuit 50 controls the switching elements 38a to 38f as follows based on the switching signals of the detection sensors 41, 42, and 43.

  The switching element 38a on the positive side of the U phase is alternately switched on and off in the section of the electrical angle of 120 ° from the timing of the electrical angle of 30 ° to the timing of the electrical angle of 150 °. Further, the switching element 38a is always turned on in the section of the electrical angle of 120 ° extending from the timing of the electrical angle of 210 ° to the timing of the electrical angle of 330 °. On the other hand, the switching element 38d on the negative phase side of the U-phase is alternately switched on and off in the section of the electrical angle of 120 ° from the timing of the electrical angle of 30 ° to the timing of the electrical angle of 1500 °. Yes.

  Further, the switching element 38b on the positive side of the V phase is always turned on in the section of the electrical angle of 120 ° from the timing of the electrical angle of 90 ° to the timing of the electrical angle of 210 °. Further, the switching element 38b on the positive side of the V phase is alternately switched on and off in the section of the electrical angle of 120 ° from the timing of the electrical angle of 270 ° to the timing of the electrical angle of 30 °. On the other hand, the switching element 38e on the negative side of the V-phase is alternately switched on and off in the section of the electrical angle of 120 ° from the timing of the electrical angle of 270 ° to the timing of the electrical angle of 30 °.

  Further, the switching element 38c on the positive side of the W phase is always turned on in the section of the electrical angle of 120 ° extending from the timing of the electrical angle of 330 ° to the timing of the electrical angle of 90 °. Further, the switching element 38c on the positive side of the W phase is alternately switched on and off in the section of the electrical angle of 120 ° from the timing of the electrical angle of 150 ° to the timing of the electrical angle of 270 °. Further, the switching element 38f on the negative side of the W phase is alternately switched on and off in a section of an electrical angle of 120 ° from a timing of an electrical angle of 150 ° to a timing of an electrical angle of 270 °.

  Next, the drive pattern of each switching element 38a-38f in the field weakening control which is 2nd electricity supply control is demonstrated based on FIG. The field weakening control is performed when the wiper arm 15 operates in the forward path, and the first energization control is performed when the wiper arm 15 operates in the backward path. 9 also shows energization stages ST1 to ST6 and an electrical angle of 0 ° to an electrical angle of 360 °, as in FIG. 9, the ON / OFF timings of the switching signals of the detection sensors 41 to 43 are the same as the ON / OFF timings of the switching signals of the detection sensors 41 to 43 in FIG.

  FIG. 9 is a driving pattern of the switching elements 38a to 38f corresponding to the forward path of the wiper arm 15. The control timing of the switching elements 38a to 38f shown in FIG. 9 is compared with the control timing of the switching elements 38a to 38f shown in FIG. Thus, the electrical angle is advanced by 30 °, that is, advanced.

  First, the switching element 38a on the positive side of the U phase is always turned on in the section of the electrical angle of 120 ° from the timing of the electrical angle of 15 ° to the timing of the electrical angle of 135 °, and from the timing of the electrical angle of 195 ° In the section where the electrical angle is 120 ° over the timing of 315 °, ON and OFF are alternately switched. In addition, the switching element 38d on the negative phase side of the U phase is alternately switched on and off in the section of the electrical angle of 120 ° from the timing of the electrical angle of 195 ° to the timing of the electrical angle of 315 °.

  Further, the switching element 38b on the positive side of the V phase is alternately switched on and off in the section of the electrical angle of 120 ° from the timing of the electrical angle of 315 ° to the timing of the electrical angle of 75 °. Further, the switching element 38b on the positive side of the V phase is turned on at a timing of an electrical angle of 135 ° and is always turned on until it is turned off at a timing of an electrical angle of 255 °. On the other hand, the switching element 38e on the negative side of the V phase is alternately switched on and off in the section of the electrical angle of 120 ° from the timing of the electrical angle of 315 ° to the timing of the electrical angle of 75 °.

  Further, the switching element 38c on the positive side of the W phase is always turned on in the section of the electrical angle of 120 ° from the timing of the electrical angle of 255 ° to the timing of the electrical angle of 15 °. Further, the switching element 38c on the positive side of the W phase is alternately switched on and off in a section of an electrical angle of 120 ° from the timing of the electrical angle of 75 ° to the timing of the electrical angle of 195 °. Further, the switching element 38c on the negative side of the W phase is alternately switched on and off in a section of an electrical angle of 120 ° from the timing of the electrical angle of 75 ° to the timing of the electrical angle of 195 °.

  The field weakening control described above is control that weakens the magnetic field formed by the armature 21 as compared with the first energization control. When this field weakening control is performed, the counter electromotive force generated in the armature coils U1, U2, V1, V2, W1, and W2 decreases, and the rotational speed of the rotor 27 increases. FIG. 10 is a diagram showing the characteristics of the brushless motor 18. In FIG. 10, the rotation speed of the brushless motor 18 is shown on the vertical axis, and the torque of the brushless motor 18 is shown on the horizontal axis. FIG. 10 shows an example of the low-speed mode characteristic and an example of the high-speed mode characteristic. Switching between the low speed mode and the high speed mode is performed by the driver operating the wiper switch 44.

  The brushless motor 18 according to the present embodiment has a single characteristic at a position indicated by a solid line, for example, so that the rotation speed and torque corresponding to the low-speed mode characteristic shown in FIG. 10 can be obtained when setting the rating. Yes. For this reason, when the low speed mode is selected, the required rotation speed and torque can be obtained within the range of the single characteristic or less by executing the first energization control.

  The single unit characteristic is a characteristic that satisfies the target output when the actual vehicle speed of the vehicle 10 is equal to or lower than the reference vehicle speed, that is, the low speed mode. The apparent characteristic is a characteristic that satisfies the target output when the actual vehicle speed of the vehicle 10 exceeds the reference vehicle speed, that is, the high-speed mode characteristic. The target output is represented by the rotation speed and torque of the rotor 27. Conditions for determining the target output include various conditions such as a detection signal of the wiper switch 44, a detection signal of the vehicle speed sensor 45, and a load of the wiper arm 15.

  On the other hand, for example, when the high speed mode is selected and the torque and the number of rotations required for the rotor 27 exceed the single unit characteristics, the control circuit 50 executes the field weakening control to thereby execute the single unit characteristics. The rotation speed and torque exceeding can be obtained. As a result, the characteristics of the brushless motor 18 are apparently equivalent to being at the position indicated by the alternate long and short dash line in FIG.

  That is, the design of the brushless motor 18 can be determined with reference to the low speed mode, and the physique of the brushless motor 18 can be made as small as possible. The fact that the torque can be increased by increasing the rotational speed of the brushless motor 18 without changing the current value means that the torque constant becomes relatively large. In other words, the brushless motor 18 of the present embodiment can generate as much torque as possible with less power consumption, and the motor efficiency is improved.

  Next, driving patterns of the switching elements 38a to 39f in the third energization control will be described with reference to FIG. The third energization control is executed when the wiper arm 15 operates in the forward path, and the first energization control is performed when the wiper arm 15 operates in the return path. The control circuit 50 detects whether the wiper arm 15 is operating in the forward path or the return path based on the rotation direction of the rotor 27.

  Also in FIG. 11, the energization stage ST1 to the energization stage ST6 and the electrical angle 0 ° to the electrical angle 360 ° are shown as in FIG. 11, the on / off timings of the switching signals of the detection sensors 41 to 43 are the same as the on / off timings of the switching signals of the detection sensors 41 to 43 in FIG.

  The control timing of the switching elements 38a to 38f shown in FIG. 11 is advanced by an interval of an electrical angle of 30 ° compared to the control timing of the switching elements 38a to 38f shown in FIG. This is the same as field weakening control.

  First, the switching element 38a on the positive side of the U phase is always turned on in the section of the electrical angle of 150 ° from the timing of the electrical angle of 15 ° to the timing of the electrical angle of 165 °, and from the timing of the electrical angle of 195 ° In the section of the electrical angle of 150 ° over the timing of 345 °, ON and OFF are alternately switched. Further, the switching element 38d on the negative phase side of the U phase is alternately switched on and off in the section of the electrical angle of 150 ° from the timing of the electrical angle of 195 ° to the timing of the electrical angle of 345 °.

  Further, the switching element 38b on the positive side of the V phase is alternately switched on and off in the section of the electrical angle of 150 ° extending from the timing of the electrical angle of 315 ° to the timing of the electrical angle of 105 °. Further, the switching element 38b on the positive side of the V phase is turned on at the timing of the electrical angle of 135 ° and is always turned on in the section of the electrical angle of 150 ° until it is turned off at the timing of the electrical angle of 285 °. On the other hand, the switching element 38e on the negative side of the V phase is alternately switched on and off in the section of the electrical angle of 150 ° from the timing of the electrical angle of 315 ° to the timing of the electrical angle of 105 °.

  Further, the switching element 38c on the positive side of the W phase is always turned on in the section of the electrical angle of 150 ° from the timing of the electrical angle of 255 ° to the timing of the electrical angle of 45 °. Further, the switching element 38c on the positive side of the W phase is alternately switched on and off in the section of the electrical angle of 150 ° from the timing of the electrical angle of 75 ° to the timing of the electrical angle of 225 °. Further, the switching element 38c on the negative side of the W phase is alternately switched on and off in the section of the electrical angle of 150 ° from the timing of the electrical angle of 75 ° to the timing of the electrical angle of 225 °.

  Thus, in the third energization control, the switching elements 38a to 38f are turned on. In the section where the electrical angle is 150 °, the switching elements 38a to 38f are turned on in the first energization control and field weakening control. The electrical angle is 30 ° longer than the 120 ° angle section. That is, the electrical angle is longer by 15 ° before and after the section of the electrical angle of 120 °.

  Next, when attaching the detection sensors 41 to 43 to the control board 36, it is assumed that an error occurs in the attachment position and the mutual distance between the detection sensors 41 to 43 is different from the target distance. In such a case, if the rotational position of the rotor 27 is estimated based on the switching signals of the detection sensors 41 to 43, a difference is generated between the actual rotational position of the rotor 27 and the estimated rotational position. For this reason, when the first energization control, the field weakening control, and the third energization control are executed based on the switching signals of the detection sensors 41 to 43, the timing and the energization period for turning on and off the switching elements 38a to 38f are not valid. May be appropriate.

  In order to avoid such an inconvenience, the driving device 37 can perform the following control. First, an example of the ideal waveform of the switching signal of the detection sensors 41 to 43 is shown in the time chart of FIG. In the time chart of FIG. 12, the electrical angle is shown in intervals of 60 ° for convenience. The ideal waveform of the switching signal of the detection sensors 41 to 43 is switched from on to off at every electrical angle of 60 °, and the edge is switched from off to on.

  In order to correct the phase shift of the switching signals of the detection sensors 41 to 43, the driving device 37 estimates an edge switching timing that occurs thereafter based on the edge switching timing of a predetermined switching signal.

  For example, if the edge switching timing ahead of an electrical angle of 120 ° is calculated for each edge timing switching, the switching signal of the V-phase detection sensor 43 is determined based on the edge switching timing of the switching signal of the U-phase detection sensor 43. Estimate edge switching timing. Further, based on the edge switching timing of the switching signal of the V-phase detection sensor 43, the edge switching timing of the switching signal of the W-phase detection sensor 43 is estimated. Further, the edge switching timing of the switching signal of the U-phase detection sensor 43 is estimated based on the edge switching timing of the switching signal of the W-phase detection sensor 43.

  Here, in the time chart shown in FIG. 13, based on the edge switching timing of the switching signal of the U-phase detection sensor 43, the calculation method of the ideal edge switching timing in the V-phase detection sensor 42 at an electrical angle of 120 ° ahead is It can represent with the following formula | equation (1) and Formula (2).

Time for electrical angle of 120 ° (Δt120) = Δt180 × 0.67 (1)
Electrical angle 120 ° ahead (p120) = Δt120 + FRT (2)
Here, 0.67 is a coefficient corresponding to the electrical angle of 120 ° with respect to the section of the electrical angle of 180 ° where the switching signal is kept on or on, Δt180 is the time corresponding to the section of the electrical angle of 180 °, and FRT is This is the time measured by the timer of the driving device 37. That is, for each edge switching timing of the switching signal of the detection sensor 43, an ideal switching timing in the switching signal of the V-phase detection sensor 42 that occurs 120 ° after the electrical angle from that timing is estimated.

  The drive device 37 according to the present embodiment obtains the phase difference from the switching timing of the actually detected switching signal based on the ideal switching timing based on the electrical angle, and corrects the phase difference, thereby correcting the ideal switching signal. Find the waveform. And the drive device 37 controls ON / OFF of switching element 38a-38f based on the ideal waveform of a switching signal, when performing 1st electricity supply control, field-weakening control, and 3rd electricity supply control.

  Next, a specific correction example of the switching signal will be described. Here, an example of correcting the switching signals of the other detection sensors 41 and 43 using the switching signal of the detection sensor 42 corresponding to the V phase as a reference signal will be described. This is because the detection sensor 42 among the detection sensors 41 to 43 is closest to the sensor magnet 34 and can detect a stable signal.

(Correction example 1)
First, an example in which the switching signal of the U-phase detection sensor 43 is corrected based on the V-phase detection sensor 42 will be described with reference to the time chart of FIG. The switching signals of the detection sensors 41 to 43 shown in FIG. 14 are the same as the switching signals of the detection sensors 41 to 43 shown in FIG. In the time chart of FIG. 14, the electrical angle is shown in intervals of 60 ° for convenience.

  As shown by the broken line, the ideal waveform of the switching signal of the detection sensor 43 is turned on at an electrical angle of 0 ° and continued on for an interval of an electrical angle of 180 °, and then at an electrical angle of 180 °. Switch off. That is, the ideal waveform of the switching signal of the detection sensor 43 is turned off at the timing of an electrical angle of 60 ° (p1) delayed by an interval of 120 ° of the electrical angle from the timing of the electrical angle of 120 ° when the switching signal of the detection sensor is turned on. Is done.

  On the other hand, after the actual waveform of the switching signal of the detection sensor 43 is turned on at the timing of the electrical angle of 30 ° and turned off over the section of the electrical angle of 180 ° as indicated by the solid line, the electrical angle It is assumed that the signal is turned off at a timing of 210 ° (p1 ′). That is, there is a phase difference (deviation) corresponding to the section of the electrical angle of 30 ° between the ideal electrical angle of 180 ° and the actual electrical angle of 210 °. This can be expressed by equation (3).

Phase difference = p1′−p1 Formula (3)
The driving device 37 constantly detects the time Δt180 corresponding to the section of the electrical angle of 180 ° by the switching signal of the detection sensor 43. Then, an ideal time Δt60 corresponding to a section of an ideal electrical angle of 60 ° from the timing when the detection sensor 42 is turned on to the timing when the detection sensor 43 is turned off is calculated. Further, the driving device 37 calculates an actual measurement time Δtreal 60 corresponding to a section of an actual electrical angle of 60 ° from the timing when the detection sensor 42 is turned on to the timing when the detection sensor 43 is turned off. Further, the driving device 37 obtains an adjustment value (correction value) AdjPhase of the switching signal of the detection sensor 43 from the difference between the ideal time Δt60 and the actual measurement time Δtreal60. This process can be expressed by Expression (4) and Expression (5).

Δt60 = Δt180 × 0.334 (4)
AdjPhase = Δt60−Δtreal60 (5)
Here, 0.334 is a coefficient of a section with an electrical angle of 60 ° relative to a section with an electrical angle of 180 ° in which the switching signal is kept on or on.

  Then, the driving device 37 performs a process of correcting the OFF timing of the switching signal of the detection sensor 43 to the timing of the electrical angle of 180 ° (p1) advanced from the electrical angle of 210 ° to the electrical angle of 30 °. That is, the electrical angle section from the timing when the switching signal of the detection sensor 42 is turned on to the timing when the switching signal of the detection sensor 43 is turned off can be an ideal electrical angle of 60 °.

(Correction example 2)
Next, an example in which the switching signal of the W-phase detection sensor 41 is corrected based on the V-phase detection sensor 42 will be described with reference to the time chart of FIG. The switching signals of the detection sensors 41 to 43 shown in FIG. 15 are the same as the switching signals of the detection sensors 41 to 43 shown in FIG. In the time chart of FIG. 15, the electrical angle is shown in intervals of 60 ° for convenience. The ideal waveform of the switching signal of the detection sensor 41 is turned off at an electrical angle of 60 ° and maintained off for an electrical angle of 180 °, and then turned on at an electrical angle of 240 °, as indicated by a broken line. Switch to That is, the ideal waveform of the switching signal of the detection sensor 41 is turned off at the timing of the electrical angle of 240 ° (p1) delayed by the interval of the electrical angle of 120 ° from the timing of the electrical angle of 120 ° when the switching signal of the detection sensor is turned on. Is done.

  On the other hand, after the actual waveform of the switching signal of the detection sensor 41 is turned on at the timing of the electrical angle of 30 ° and turned off over the section of the electrical angle of 180 ° as indicated by the solid line, the electrical angle It is assumed that the signal is turned on at a timing of 210 ° (p1 ′). That is, there is a phase difference (deviation) corresponding to the section of the electrical angle of 30 ° between the ideal electrical angle of 240 ° and the actual electrical angle of 210 °. This phase difference is expressed by Equation (6).

Phase difference = p1−p1 ′ (6)
The driving device 37 constantly detects the time Δt180 corresponding to the section of the electrical angle of 180 ° by the switching signal of the detection sensor 41. Then, an ideal time Δt120 corresponding to a section of an ideal electrical angle of 120 ° from the timing when the detection sensor 42 is turned on to the timing when the detection sensor 41 is turned off is calculated. Further, the control circuit 50 calculates an actual measurement time Δtreal 120 corresponding to a section of an actual electrical angle of 90 ° from the timing when the detection sensor 42 is turned on to the timing when the detection sensor 41 is turned off. Further, the control circuit 50 obtains an adjustment value (correction value) AdjPhase of the switching signal of the detection sensor 41 from the difference between the ideal time Δt120 and the actual measurement time Δtreal120. This process is expressed by equation (7).

AdjPhase = Δt120−Δtreal120 (7)
Then, the control circuit 50 detects the detection sensor 43 at the timing of the electrical angle of 360 ° (p2) in the section of the electrical angle of 120 ° from the electrical angle of 240 ° that is the OFF timing of the corrected switching signal of the detection sensor 41. Turn on the switching signal. That is, the electrical angle section from the timing when the switching signal of the detection sensor 41 is turned on to the timing when the switching signal of the detection sensor 43 is turned on can be an ideal electrical angle of 120 °. This process is expressed by equation (8).

p2 = p120 + AdjPhase (8)
This equation (8) obtains the electrical angle timing P2 of the switching signal turned on at the electrical angle of 120 ° (p120) from the electrical angle of 210 ° using the adjustment value (correction value) AdjPhase. Means that.

  In addition, the switching signal of the detection sensor 43 is turned on at a timing of an electrical angle of 330 ° (p2 ′) with a section of the electrical angle of 120 ° from the electrical angle of 210 ° which is an off timing before the switching signal of the detection sensor 41 is adjusted. When the correction is performed, a phase difference corresponding to a section with an electrical angle of 30 ° is generated from the ideal electrical angle of 360 °.

  Next, the above control method will be described comprehensively with reference to the flowchart of FIG. The drive device 37 detects the edge switching timing of the switching signal of any one of the U-phase detection sensor 43, the V-phase detection sensor 42, and the W-phase detection sensor (step S1). Steps S2 to S5 are executed.

The process of step S2 is
Tn-3 = Tn-2
The process of step S3 is
Tn-2 = Tn-1
The process of step S4 is
Tn-1 = Tn
It is represented by

  Tn is the latest measurement time corresponding to the section of electrical angle 60 °, Tn-1 is the measurement time corresponding to electrical angle 60 ° one time before the latest measurement time, and Tn-2 is The measurement time corresponds to an electrical angle of 60 ° two times before the latest measurement time, and Tn-3 is the measurement time corresponding to an electrical angle of 60 ° three times before the latest measurement time. That is, in step S2 to step S4, it means updating the measurement time of the electrical angle of 60 ° from the previous one to the third time. In step S5, the drive device 37 acquires the latest measurement time corresponding to the section having an electrical angle of 60 °.

  In step S <b> 6 subsequent to step S <b> 5, the driving device 37 determines whether or not it is a timing at which the edge of the switching signal of the U-phase detection sensor 43 is switched. If the drive device 37 determines YES in step S6, the drive device 37 proceeds to step S7. For example, an example in which YES is determined in step S6 is the timing of the electrical angle of 360 ° in FIG. Then, in step S7, the driving device 37 obtains a time Δt120 corresponding to a section with an electrical angle of 120 ° from a time Δt180 corresponding to a section with an electrical angle of 180 ° of the switching signal of the detection sensor 43.

  Following step S7, the drive device 37 executes the processes of steps S8 to S11, executes the process of step S17, and ends the control routine. The processing in steps S8 to S11 is the processing described with reference to the time chart of FIG. First, the process of step S8 is a process for obtaining an ideal time Δt60 corresponding to a section with an ideal electrical angle of 60 ° from a time Δt180 corresponding to a section with an electrical angle of 180 ° of the switching signal of the U-phase detection sensor 43. is there.

  The process of step S9 is a process for obtaining an actual measurement time Δtreal60 corresponding to a section of an actual electrical angle of 60 ° from the timing when the detection sensor 42 is turned on to the timing when the detection sensor 43 is turned off.

The process of step S10 is a process for obtaining a phase difference (deviation) between the section with an ideal electrical angle of 60 ° and the section with an actual electrical angle of 60 °. This process
Phase difference = Δt60−Δt60 ′
It is represented by Here, Δt60 ′ has the same meaning as Δtreal60 in Equation (5).

  Further, in step S11, a process of correcting the OFF timing of the switching signal of the detection sensor 43 to a timing of an electrical angle of 180 ° (p1) advanced from an electrical angle of 210 ° to an electrical angle of 30 ° is performed.

  The process of step S17 is executed by selecting any one of the first energization control, the field weakening control, and the third energization control using the reference switching signal and the corrected switching signal.

  On the other hand, if the drive device 37 determines NO in step S6, it determines in step S12 whether or not it is the timing at which the switching signal of the detection sensor 41 is switched. If the drive device 37 determines YES in step S12, it executes the processing of step S13 to step S16, and ends the control routine via step S17.

  The processing from step S13 to step S16 is the processing described with reference to the time chart of FIG. First, the process of step S13 is a process for obtaining an ideal time Δt120 corresponding to a section with an ideal electrical angle of 120 ° from a time Δt180 corresponding to a section with an electrical angle of 180 ° of the switching signal of the W-phase detection sensor 41. is there.

The process of step S14 includes a time Δt120 ′ corresponding to a section with an ideal electrical angle of 120 ° from the timing when the detection sensor 42 was turned on most recently until the detection sensor 43 is turned on.
Δt120 ′ = Tn−Tn−1
It is a process to obtain as.

The process of step S15 is a process for obtaining a phase difference (shift) between the section with an ideal electrical angle of 120 ° and the section with an actual electrical angle of 90 °. This process
Phase difference = Δt120−Δt120 ′
It is represented by

  Further, in step S16, a process of correcting the ON timing of the switching signal of the detection sensor 41 to the timing of the electrical angle 240 ° (p1) delayed in the section from the electrical angle 210 ° to the electrical angle 30 ° is performed.

  As described above, the motor device 17 can correct the switching signals of the detection sensors 41 and 43 based on the switching signal of the detection sensor 42. For this reason, even when the distance between the detection sensors 41, 42, and 43 has an error with respect to the ideal distance, the first energization control, the field weakening control, and the third energization control are performed using the corrected switching signal. Can be performed appropriately. That is, the rotational speed, torque, and the like of the rotor 27 of the brushless motor 18 can be obtained in accordance with conditions such as the operation position, operation direction, load, and mode of the wiper arm 15. Therefore, the efficiency of the motor device 17 can be improved, noise can be suppressed, and vibration can be avoided.

  Furthermore, since the switching signals of the detection sensors 41, 42, and 43 can be corrected, the detection sensors 41, 42, and 43 can be arranged on the same plane of the control board 36. For this reason, it is not necessary to provide a dedicated sensor support member for attaching the three detection sensors around the rotor. For this reason, it is not necessary to provide lead wires or the like for connecting the three detection sensors provided on the dedicated sensor support member and the control circuit. Therefore, the motor device 17 can be reduced in size and cost.

  The driving device 37 described in the above embodiment corresponds to a signal correction unit and an element control unit of the present invention. In the first energization control, the timing of the electrical angle of 30 ° when the switching element 38a is turned on corresponds to the first timing in the present invention, and the electric power at which the switching element 38a is turned on by field weakening control and third energization control. The timing at an angle of 15 ° corresponds to the second timing in the present invention. Further, the speed reduction mechanism 19 and the pivot shaft 14 correspond to the power transmission mechanism of the present invention. Furthermore, Steps S7 to S11 and Steps S13 to S16 correspond to the first step in the present invention, and Step S17 corresponds to the second step in the present invention.

  Needless to say, the drive device of the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the scope of the present invention. For example, it is possible to correct the switching signal of another detection sensor using the switching signal of the U-phase detection sensor. It is also possible to correct the switching signal of another detection sensor using the switching signal of the W-phase detection sensor. Furthermore, the brushless motor of the present invention includes a star connection structure in which armature coils are connected in a Y shape. The brushless motor of the present invention includes a motor whose rotor has an IPM (Interior Permanent Magnet) structure. The IPM structure has a permanent magnet embedded in the rotor core. Further, the first period is not limited to the electrical angle of 120 °, and may be less than the electrical angle of 120 ° or may exceed the electrical angle of 120 °.

  The brushless motor of the present invention includes an inner rotor type structure in which the rotor is disposed inside the stator, and an outer rotor type structure in which the rotor is disposed outside the stator.

  The wiper device of the present invention includes a wiper blade that wipes the rear glass. That is, the window glass in the wiper device of the present invention includes a front window glass and a rear window. In addition, the wiper device of the present invention includes a configuration in which two wiper arms are independently driven by one brushless motor.

  The brushless motor according to the present embodiment is provided for operating an operation member such as a door, a roof, and a glass in a power slide door device, a sunroof device, a power window device, and the like provided in a vehicle in addition to a wiper motor that operates the wiper device. Including a brushless motor.

DESCRIPTION OF SYMBOLS 10 Vehicle 11 Front window glass 12 1st wiper apparatus 13 2nd wiper apparatus 14 Pivot shaft 15 Wiper arm 16 Wiper blade 17 Motor apparatus 18 Brushless motor 19 Reduction mechanism 20 Motor case 21 Armature 22 Stator core 23 Teeth 24, 25, 26 Terminal 27 Rotor 28 Rotor shaft 29N, 29S Permanent magnet 30 Rotor core 31 Gear case 32 Worm 33 Worm wheel 33a Gear 34 Sensor magnet 35 Under cover 36 Control board 37 Drive circuit 38 Inverter circuits 38a to 38f Switching element 39 Connector 40 External power supply 41, 42, 43 detection sensor 44 wiper switch 45 vehicle speed sensor 46 mounting portion 47 buffer material 47a hole 48 vehicle body 49 bearing 50 control circuit 51 signal generation circuit A1 first axis B1 first 2 axis U1, U2, V1, V2, W1, W2 Armature coils Ua, Ub, Va, Vb, Wa, Wb End

Claims (4)

A wiper device comprising a wiper blade for wiping a windshield of a vehicle, a wiper arm to which the wiper blade is attached, and a motor device for driving the wiper arm ,
The motor device is
A brushless motor for driving the wiper arm;
A driving device for controlling the brushless motor;
A control board provided with the driving device;
A gear case containing the driving device and the control board;
Have
The brushless motor is
A stator having a plurality of coils to which current is supplied;
A rotor that is rotated by a rotating magnetic field formed by the stator, and in which a worm is formed;
Have
In the gear case,
A worm wheel meshing with the worm;
A pivot shaft that rotates integrally with the worm wheel;
Is provided,
A plurality of detection sensors that are provided in different phases in the rotation direction of the rotor and that generate an output signal by detecting the phase in the rotation direction of the rotor are attached to the control board,
The driving device includes:
An inverter circuit having a plurality of switching elements for controlling energization to the coil and connecting or blocking a current path to the coil;
A signal correction unit that corrects an output signal of another detection sensor using an output signal of any one of the plurality of detection sensors as a reference signal;
An element control unit for controlling the plurality of switching elements;
With
The element controller is
By controlling the plurality of switching elements based on the reference signal and the corrected output signal, first energization is started at the first timing to control the output of the rotor. Energization control,
The plurality of coils from a second timing advanced by a predetermined electrical angle from the first timing by controlling the plurality of switching elements based on the reference signal and the corrected output signal. A second energization control for energizing and controlling the output of the rotor;
Wiper device that switches between and executes . The wiper device according to claim 1,
The element control unit executes a third energization control for continuing energization of the plurality of coils for a time longer than a time during which energization of the plurality of coils is continued in the second energization control. apparatus. The wiper device according to claim 1 or 2,
The wiper device , wherein the element control unit stores energization pattern data for the plurality of coils . It is a control method of the wiper device given in any 1 paragraph of Claims 1-3,
Correcting an output signal of another detection sensor using an output signal of any one of the plurality of detection sensors as a reference signal;
By controlling the plurality of switching elements based on the reference signal and the corrected output signal, first energization is started at the first timing to control the output of the rotor. Energization control or a second timing advanced by a predetermined electrical angle from the first timing by controlling the plurality of switching elements based on the reference signal and the corrected output signal Switching and executing second energization control for energizing the plurality of coils to control the output of the rotor;
A method for controlling a wiper device.

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