JP2004189197A - Wiper controlling method, wiper, and motor with speed reducer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely detect a position of a wiper arm with a small number of sensors. <P>SOLUTION: In a sensor magnet 41 mounted to an output shaft 34, when wiper arms 1a, 1b are positioned on an upward reverse rotation position B side relative to an original position O, hole ICs 37a, 37b are opposed to an S pole. When the wiper arms 1a, 1b are positioned on a downward reverse rotation position A side with relative to the original position O, at least one of the hole ICs 37a, 37b is opposed to an N pole. When the wiper arms 1a, 1b are abnormally stopped, it is judged whether the wiper arms 1a, 1b are positioned on either side of the downward reverse rotation position A or the upward reverse rotation position B relative to the original position at the time of restarting, so that the wiper arms 1a, 1b are always started towards the original position O. After the position of the wiper arm is surely grasped by two hole ICs 37a, 37b, and the wiper arms are restarted towards the original position O to reset position data, normal control is performed. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a forward-reversely driven motor and a control method thereof, and more particularly, to a technique that is effective when applied to a motor of an automobile wiper device.
[0002]
[Prior art]
As a drive source of a wiper device for a vehicle such as an automobile, an electric motor operated by a power supply such as a battery mounted on the vehicle is used. Such an electric motor is provided with a reduction mechanism for reducing the number of rotations of the output shaft to a required number of rotations, and forms one unit as an electric motor with a reduction mechanism. One or two motor units are used in the wiper device, and the wiper arm swings between an upper reversing position and a lower reversing position by using the motor unit as a driving source. When using one motor unit, the wiper arms on the driver's seat side and the passenger's seat side are connected by a link and driven synchronously. When two motor units are used, the motor units are attached to the wiper arms on the driver's seat side and the passenger's seat side, and both wiper arms are driven synchronously while detecting the rotation of the amateur shaft and the output shaft.
[0003]
On the other hand, the installation space for the wiper system has been reduced year by year due to the enlargement of the engine and the master power of the brake. For this reason, in recent years, a method has been put to practical use in which the operating area of the link is reduced to less than half by rotating the motor forward and backward within 180 °, and the wiper can be driven in a small space. In this motor forward / reverse rotation method, since the reversing operation can be performed at an arbitrary position within the wiping angle, the storage position can be set further below the lower reversal position after setting the lower reversal position. Therefore, many luxury cars adopt this method and incorporate a wiper storage function.
[0004]
In order to perform forward / reverse rotation of the motor in the wiper system, it is necessary to detect the position of the wiper arm in order to perform forward / reverse rotation of the motor at an arbitrary position. The detection of the wiper arm position is performed by adding or subtracting the number of pulses generated in conjunction with the rotation of the motor. A multipolar magnetized magnet is attached to the motor rotation shaft, and a sensor such as a Hall IC that captures a change in magnetic pole accompanying the rotation and outputs a pulse signal is arranged to face the magnet. The pulse count is reset at one point (origin position) serving as a reference for the rotational position of the motor unit output shaft, thereby preventing the occurrence of a pulse shift. A magnet is also attached to the output shaft, and a sensor is arranged so that a reference signal is output when the magnetic pole approaches a predetermined position.
[0005]
The motor rotation angle from the reference position is calculated by pulse addition and subtraction from the reset, and the current wiper arm position can be detected by considering the reduction ratio, the link ratio, and the like. Also, the wiper arm moving speed can be detected from the cycle of the motor rotation pulse. The motor control system includes a forward / reverse rotation circuit such as an H-bridge circuit using an FET, and control means such as a CPU for controlling the speed and rotation angle of the motor. The motor is driven based on the position and speed of the wiper arm. Control is performed.
[0006]
[Patent Document 1] JP-A-11-301409
[Patent Document 2] JP-A-2002-262515
[0007]
[Problems to be solved by the invention]
However, in such a wiper system based on the forward / reverse rotation of the motor, if an abnormal situation such as power being shut off during wiping occurs, the pulse count indicating the wiper arm position also disappears, and the wiper arm position may be recognized at the time of restart. become unable. For this reason, in the first operation immediately after the restart, the blade overruns and collides with the pillar at the end of the windshield, or mechanical components hit the mechanical stopper provided in the motor unit or the link mechanism. And sometimes touched.
[0008]
Therefore, a sensor that detects the rotational position of the output shaft is provided not only at the home position but also at the upside down position and the storage position. A configuration to prevent run is adopted. However, in such a configuration, it is necessary to attach at least four expensive sensors to one motor unit, and there has been a problem that the unit price increases and causes a cost increase.
[0009]
An object of the present invention is to provide a configuration capable of reliably detecting the position of a wiper arm with a small number of sensors.
[0010]
[Means for Solving the Problems]
The control method of the wiper device according to the present invention is a control method of a wiper device that detects a position of the wiper arm based on a time when the wiper arm is at a reference position and performs the reciprocal wiping operation of the wiper arm between an upper reversing position and a lower reversing position. When the wiper arm is stopped between the upper reversing position and the lower reversing position during operation, the wiper arm is always started toward the reference position when restarting.
[0011]
According to the present invention, even when the wiper arm is abnormally stopped between the upper inverted position and the lower inverted position due to power interruption or the like, the wiper arm always passes through the reference position when restarting, so that the position of the wiper arm can be accurately grasped. can do.
[0012]
In the control method of the wiper device, a storage position of the wiper arm is provided below the lower reversing position, and when the wiper arm is stopped at a position other than the storage position during operation, the wiper arm is always set to the reference position at restart. You may make it start toward a position.
[0013]
The wiper device of the present invention is a wiper device driven by an electric motor with a reduction mechanism having a motor main body having a rotation shaft, and a reduction mechanism for reducing the rotation of the rotation shaft and transmitting the rotation to an output shaft, A wiper arm connected to the output shaft for performing a reciprocating wiping operation between an upper reversing position and a lower reversing position, and a first magnetic member arranged to face a predetermined position of the output shaft when the wiper arm is at a reference position. A detection element, a second magnetic detection element arranged at a predetermined angle away from the first magnetic detection element, and a first magnetic pole and a second magnetic pole provided on the output shaft and having different polarities along a circumferential direction. Wherein the first and second magnetic detecting elements are both opposed to the second magnetic pole when the wiper arm is on the upper reversing position side with respect to the reference position, and the wiper arm is inverted downward with respect to the reference position. At least one of the first and second magnetic detecting element when in 置側 is characterized in that it comprises a sensor magnet which faces the first magnetic pole.
[0014]
In the present invention, it is determined whether the wiper arm is on the upper reversing position side or the lower reversing position side with respect to the reference position by determining the polarities of the first and second magnetic poles in the first and second magnetic detecting elements. be able to. Thus, even when the wiper arm is abnormally stopped between the upper reversing position and the lower reversing position due to power interruption or the like, the wiper arm can always be started in the reference position direction when restarting.
[0015]
In the wiper device, when the wiper arm passes the reference position, the first magnetic detection element may face a boundary between the first magnetic pole and the second magnetic pole. In the wiper device, when the wiper arm is at the lower reversal position, the first and second magnetic detection elements may both face the first magnetic pole. Further, in the wiper device, a storage position of the wiper arm is provided below the lower reversing position, and when the wiper arm is in the storage position, the first magnetic detection element faces the first magnetic pole, and A magnetic detecting element may be opposed to the second magnetic pole.
[0016]
In the wiper device, when the wiper arm stops between the upper reversal position and the lower reversal position during operation, the wiper arm may always start toward the reference position when restarting. Further, when the wiper arm stops at a position other than the storage position during operation, the wiper arm may always start toward the reference position when restarting. Thus, even if the wiper arm is abnormally stopped due to power interruption or the like, the wiper arm always passes the reference position when restarting, so that the position of the wiper arm can be accurately grasped by the two magnetic detection elements.
[0017]
In the wiper device, the wiper device further includes a sensor that detects a rotation angle of the rotation shaft, and starts detecting the rotation angle of the rotation shaft with the wiper arm at the reference position as a base point. May be.
[0018]
On the other hand, an electric motor with a reduction mechanism of the present invention is an electric motor with a reduction mechanism having a motor main body having a rotating shaft, and a reduction mechanism for reducing the rotation of the rotating shaft and transmitting the rotation to an output shaft. A first magnetic detecting element disposed at a reference position where a predetermined portion of the output shaft faces when the shaft is in a predetermined state; and a second magnetic detecting element disposed at a position separated by a predetermined angle from the first magnetic detecting element. And a first magnetic pole and a second magnetic pole provided on the output shaft and having different polarities from each other along a circumferential direction, and the first and second magnetic poles are arranged when the output shaft is in one direction with respect to the reference position. A sensor magnet in which at least one of the first and second magnetic detecting elements is opposed to the first magnetic pole when both of the magnetic detecting elements are opposed to the second magnetic pole and the output shaft is on the other side with respect to the reference position. It is special to have To.
[0019]
According to the present invention, it is possible to determine in which rotational direction the output shaft is located with respect to the reference position by determining the polarities of the first and second magnetic poles in the first and second magnetic detecting elements. Thus, even when the motor is abnormally stopped due to power interruption or the like, it is possible to always start the motor such that a predetermined portion of the output shaft faces the reference position at the shortest angle when restarting.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory view schematically showing a wiper device using an electric motor with a speed reduction mechanism as a drive source according to an embodiment of the present invention, and FIG. 2 is a sectional view showing the structure of the electric motor shown in FIG. FIG. 3 is a partially cutaway sectional view showing an engaged state of the worm gear shown in FIG.
[0021]
The wiper device shown in FIG. 1 has a wiper arm 1a on the driver's seat side and a wiper arm 1b on the passenger's seat side which are swingably provided on the vehicle body. A wiper blade 2a on the driver's seat side and a wiper blade 2b on the passenger's seat side are attached to the wiper arms 1a and 1b. The wiper blades 2a and 2b are in resilient contact with the windshield 3 by a spring member or the like (not shown) provided inside the wiper arms 1a and 1b. The vehicle body is provided with two wiper shafts 4a and 4b, and the wiper arms 1a and 1b are attached to the wiper shafts 4a and 4b at their base ends.
[0022]
The wiper blades 2a and 2b oscillate between the lower reversing position A and the upper reversing position B, that is, the wiping range 5 indicated by a dashed line in the drawing, thereby wiping rain and snow attached to the windshield 3. Is done. The wiper blades 2a and 2b are moved to the storage position C located below the lower inversion position A and stored in the storage unit 6 when the wiper is stopped. The storage unit 6 is provided inside a hood of a vehicle body (not shown). By storing the wiper blades 2a, 2b in the storage section 6, the front view of the vehicle is improved. An origin position (reference position) O is set to the wiper blades 2a and 2b about 15 ° above the lower inversion position A as a control reference position.
[0023]
In order to swing the wiper arms 1a and 1b, the wiper device is provided with two electric motors 7a and 7b with a reduction mechanism (hereinafter abbreviated as motors 7a and 7b). As shown in FIG. 2, the motors 7a and 7b include a motor body 8 and a speed reduction mechanism 9. The motor housing 10 of the motor body 8 is formed in a bottomed cylindrical shape. The casing 11 of the speed reduction mechanism 9 includes a cylindrical bearing 11a having substantially the same dimensions as the motor housing 10, a gear chamber 11b, and a communication unit 11c. These members are connected by a fastening member (not shown) in a state where the opening end 10a of the motor housing 10 and the bearing 11a of the casing 11 are in contact with each other.
[0024]
Two permanent magnets 12 and 13 are provided on the inner peripheral surface of the motor housing 10 with magnetic poles different from each other facing each other, and form a magnetic field inside the motor housing 10. An armature 14 is provided inside the motor housing 10 in the magnetic field. The rotating shaft 15 of the amateur 14 is rotatably supported by self-aligning bearings 16 and 17. The bearings 16 and 17 are provided on the bottom 10b and the bearing 11a of the motor housing 10.
[0025]
The amateur 14 has an amateur core 18 in which a plurality of slots are formed. An amateur coil 19 is formed by winding a copper wire around each slot. A commutator 20 is mounted on the left side of the amateur core 18 in the figure. The commutator 20 includes a resin body 20a fixed to the rotating shaft 15, and a plurality of commutator pieces 20b radially arranged on the outer periphery of the body 20a insulated from each other. Each commutator piece 20 b is connected to the amateur coil 19.
[0026]
A brush holder 21 is provided inside the bearing 11a. Two brushes 22 and 23 are attached to the brush holder 21. The brushes 22, 23 are urged toward the commutator piece 20b, and come into contact with the commutator piece 20b in that state. The communication section 11c is provided with a power supply terminal 25 connected to the brushes 22, 23 by a wiring 24. By supplying a current to the power supply terminal 25 from a control unit (not shown), currents in opposite directions are supplied to the brushes 22 and 23, respectively.
[0027]
Since the amateur coil 19 is located in the magnetic field, when a rectified current flows through the amateur coil 19 via the commutator 20, a rotational force is generated in the amateur 14 based on Fleming's left-hand rule. Therefore, by controlling the current flowing through the amateur coil 19, the rotation angle, rotation direction, rotation speed, and the like of the rotating shaft 15 can be controlled.
[0028]
The rotating shaft 15 protrudes inside the gear chamber 11b. The tip 15a of the rotating shaft 15 is located near the wall surface 26 of the gear chamber 11b opposite to the motor body 8. As shown in FIG. 3, two worms 27 and 28 whose screw directions are formed in opposite directions are formed on the outer peripheral surface of the rotary shaft 15 located inside the gear chamber 11 b. Inside the gear chamber 11b, two worm wheels 29, 30 are provided so as to mesh with the worms 27, 28, thereby forming a worm gear 31. The worm wheels 29 and 30 are coaxially provided with pinion gears 32 and 33, respectively. A drive gear 35 as a rotating body integrally formed with the output shaft 34 of the reduction mechanism 9 meshes with the pinion gears 32 and 33. The rotation of the rotating shaft 15 is reduced by the worm gear 31, the respective pinion gears 32 and 33, and the driving gear 35 and transmitted to the output shaft 34.
[0029]
The output shafts 34 of the motors 7a and 7b are mechanically connected to the wiper shafts 4a and 4b, respectively. The wiper shafts 4a and 4b rotate integrally with the output shaft 34. When the rotating shaft 15 rotates, the worms 27 and 28 receive a thrust force acting in the axial direction of the rotating shaft 15 by the worm wheels 29 and 30. At this time, since the screw directions of the worms 27 and 28 are formed in opposite directions, the thrust forces act in opposite directions. Accordingly, the movement of the rotating shaft 15 in the thrust direction is suppressed, and it is not necessary to provide the rotating shaft 15 with a thrust bearing or the like. In the present embodiment, a two-stage reduction mechanism including the worm gear 31, the pinion gears 32, 33, and the drive gear 35 is used as the reduction mechanism 9, but the invention is not limited to this. Alternatively, a device using a planetary gear mechanism or the like may be used.
[0030]
A printed board 36 is attached to the wall surface 26 of the casing 11 perpendicularly to the rotating shaft 15. The connection terminal 40 located in the communication part 11c is attached to the printed board 36. Power is supplied from a control unit (not shown) and a detection signal is transmitted from the connection terminal 40.
[0031]
On the printed circuit board 36, two Hall ICs 37a and 37b for detecting an absolute position as first sensors, and Hall ICs 38 and 39 for detecting a relative position as a second sensor are mounted. In this case, as the Hall ICs 37a and 37b, those that can determine the type of the magnetic pole together with the magnetic pole change, that is, whether the detection target is the N pole or the S pole, are used. In this embodiment, the Hall IC is used as the relative position detection sensor. However, the present invention is not limited to this, and other types of sensors such as an optical encoder using a photodiode or an infrared sensor may be used. Is also good.
[0032]
The Hall IC is a sensor that transmits a pulse signal by converting a change in a magnetic field into a current, and a magnet is required as a detected member of the Hall IC. As a member to be detected of the Hall ICs 37a and 37b for detecting the absolute position, a ring-shaped sensor magnet 41 is attached to the outer peripheral portion of the side surface of the drive gear 35 on the lower side in the figure. The sensor magnet 41 is configured to rotate integrally with the drive gear 35, and is magnetized in two poles in the rotation direction. A multi-pole magnetized magnet 42 (hereinafter abbreviated as magnet 42) is attached to the tip 15 a of the rotating shaft 15 as a member to be detected by the Hall ICs 38 and 39 for relative position detection. The magnet 42 is configured to rotate integrally with the rotating shaft 15 and is magnetized into six poles in the rotation direction.
[0033]
FIG. 4 is an explanatory diagram showing the relationship between the Hall ICs 37a and 37b and the sensor magnet 41. As shown in FIG. 4, the magnetizing angle of one pole (here, the S pole) of the sensor magnet 41 is larger than that of the other pole (here, the N pole). When the drive gear 35 rotates, the magnetic pole passing in front of the Hall ICs 37a and 37b changes accordingly. Then, as described later, the positions of the wiper arms 1a and 1b can be recognized by a combination of the changes.
[0034]
On the other hand, the Hall ICs 38 and 39 are mounted at positions facing the magnet 42 on the surface of the printed circuit board 36 with a phase shifted by 90 degrees with respect to the rotation direction of the magnet 42. When the rotation shaft 15 rotates, the Hall ICs 38 and 39 output six cycles of pulses for each rotation of the rotation shaft 15. This pulse is transmitted to a control unit (not shown) via the connection terminal 40, and the rotation angle of the rotary shaft 15 can be detected by counting the pulse. Further, since the phases of the Hall ICs 38 and 39 are shifted by 90 degrees, the order of appearance of the pulses transmitted by the Hall ICs 38 and 39 differs depending on the rotation direction of the rotating shaft 15. Therefore, the direction of rotation of the rotating shaft 15 can be detected from the order in which the pulses appear. Further, the rotation speed of the rotating shaft 15 can be detected from the cycle of the pulses detected by the Hall ICs 38 and 39.
[0035]
Next, the operation of the motor will be described. When a wiper switch (not shown) is turned on, currents in opposite directions are supplied from the control unit to the brushes 22 and 23, and a current rectified by the commutator 20 flows through the armature coil 19. Due to this current, a rotating force is generated in the armature coil 19, and the rotating shaft 15 rotates. The rotation of the rotating shaft 15 is reduced by the worm gear 31 of the reduction mechanism 9, the pinion gears 32 and 33, and the driving gear 35 and transmitted to the output shaft 34. When the output shaft 34 rotates, the wiper arms 1a and 1b attached to the wiper shafts 4a and 4b operate accordingly.
[0036]
Here, when the wiper arms 1a and 1b are at the storage positions, the S pole and the N pole of the sensor magnet 41 face the Hall ICs 37a and 37b, respectively. Therefore, the detection signal becomes “37a: S, 37b: N” as shown in FIG. When the output shaft 34 rotates and the wiper arms 1a, 1b come to the lower inverted position, the N pole of the sensor magnet 41 also faces the Hall IC 37a, and the detection signals of the Hall ICs 37a, 37b are as shown in FIG. As shown, “37a: N, 37b: N” is obtained. When the output shaft 34 further rotates and the wiper arms 1a and 1b come to the origin position, the Hall IC 37a moves from the N pole of the sensor magnet 41 to the S pole. At this time, the detection signals of the Hall ICs 37a and 37b are “37a: N → S, 37b: S” as shown in FIG. Then, when the wiper arms 1a, 1b come to the upper reversing position, the S poles of the sensor magnet 41 both face the Hall ICs 37a, 37b, and the detection signals of the Hall ICs 37a, 37b become "37a" as shown in FIG. : S, 37b: S ".
[0037]
On the other hand, when moving from the upper inversion position to the lower inversion position, when the wiper arms 1a and 1b come to the origin position, the Hall IC 37a moves from the S pole of the sensor magnet 41 to the N pole. At this time, the detection signals of the Hall ICs 37a and 37b are “37a: S → N, 37b: S” as shown in FIG. FIG. 5 is a table summarizing these transitions. As shown in FIG. 5, the combination of magnetic poles detected by the Hall ICs 37a and 37b is different at each control point, and by determining the combination, the current position of the wiper arms 1a and 1b can be generally known. In addition, the movement direction of the wiper arms 1a and 1b can be detected by detecting the change in the magnetic pole when passing through the origin. That is, here, four positions can be recognized by the two Hall ICs 37a and 37b. The magnetic poles of the sensor magnet 41 may have opposite polarities at the S and N portions.
[0038]
Therefore, consider a case where the power is turned off when the wiper arms 1a and 1b are between the upper reversing position and the lower reversing position. At this time, the pulse counts of the wiper arms 1a and 1b disappear, and the positions of the wiper arms 1a and 1b are unknown when restarting. Therefore, if the motor is driven as it is, the exact positions of the wiper arms 1a and 1b cannot be grasped as described above, and there is a risk of overrun. On the other hand, in the motor, the wiper arms 1a and 1b are first driven in the direction of the origin position O in order to grasp the positions of the wiper arms 1a and 1b anyway. At this time, when the wiper arms 1a, 1b are between the upper reversing position and the origin position O, the signals from the Hall ICs 37a, 37b are "37a: S, 37b: S". On the other hand, when the signals from the Hall ICs 37a and 37b are a combination other than "37a: S, 37b: S", the wiper arms 1a and 1b are on the lower inversion position side of the origin position O.
[0039]
Therefore, when the signals of the Hall ICs 37a and 37b are "37a: S, 37b: S", the wiper arms 1a and 1b always pass through the origin position O if the wiper arms 1a and 1b are operated toward the lower inversion position. When the signals of the Hall ICs 37a and 37b are other than "37a: S, 37b: S", the wiper arms 1a and 1b always pass through the origin position O when the wiper arms 1a and 1b are operated toward the upper reversing position. That is, by examining the combination of signals from the two Hall ICs 37a and 37b, it is possible to determine which side the wiper arms 1a and 1b are located with respect to the origin position O. Then, if the wiper arms 1a and 1b are started toward the origin position O in accordance with the movement, the wiper arms 1a and 1b surely pass the origin position O, and the positions are determined at that time.
[0040]
After confirming the positions of the wiper arms 1a and 1b by passing through the origin positions, normal pulse count control is performed. That is, the controller starts counting the pulses of the Hall ICs 38 and 39 with the origin position O as a base point, and detects the rotation angle of the output shaft 34 based on the number of counted pulses. For example, when the wiper arms 1a and 1b operate toward the upper reversing position B, the wiper arms 1a and 1b are turned upside down by the appearance order of the pulses transmitted by the Hall ICs 38 and 39 or the signal change of the Hall IC 37a at the origin position O. The operation toward the position B, that is, the operation direction of the wiper arms 1a and 1b is detected. Then, the absolute positions of the wiper arms 1a and 1b are detected based on the rotation angle and the rotation direction of the output shaft 34.
[0041]
When the wiper arms 1a and 1b continue operating and a predetermined number of predetermined pulses are counted, the control unit recognizes that the wiper arms 1a and 1b are at the upper reversing position B. Accordingly, the direction of the current supplied to the brushes 22 and 23 is changed. When a reverse current is supplied to the brushes 22 and 23, the direction of the rotational force generated in the armature coil 19 becomes reverse, and the motor reverses. By the reverse rotation of the motor, the operation directions of the wiper arms 1a and 1b are changed to the opposite directions at the upper inversion position B, and the wiper arms 1a and 1b operate toward the lower inversion position A.
[0042]
When the wiper arms 1a and 1b pass through the origin position O, the signal of the Hall IC 37a changes from S to N, and the pulse count of the Hall ICs 38 and 39 is reset. Thereafter, pulse counting is performed toward the lower inversion position A, and when a predetermined number of pulses are counted, the control unit recognizes that the wiper arms 1a and 1b are at the lower inversion position A. Accordingly, the motor is again rotated reversely, and the wiper arms 1a and 1b operate toward the upper reversing position B. By repeating these operations, the wiper arms 1a and 1b swing between the lower inversion position A and the upper inversion position B, and the wiping operation by the wiper blades 2a and 2b is performed.
[0043]
When a wiper switch (not shown) is set to the off position, and when it is detected that the wiper arms 1a and 1b have first turned to the lower reversal position A after the wiper switches are turned off, the control unit lowers the wiper arms 1a and 1b. The operation is performed from the reverse position A toward the storage unit 6. At this time, the counting of the pulses of the Hall ICs 38 and 39 is continued. When the predetermined number of pulses have been counted, the control unit recognizes that the wiper arms 1a and 1b have reached the storage position C and supplies the brushes 22 and 23. Turn off the current.
[0044]
As described above, in the motor, even if an abnormal stop occurs due to power interruption or the like, the wiper arms 1a and 1b are always operated in a direction to pass through the origin position O when returning from the abnormal stop position. Then, after the data is reset by passing the origin position O, the operation is performed so as to reach the upper or lower inversion position. For this reason, the current position cannot be recognized at the time of restarting after an abnormal stop, and it is possible to prevent occurrence of a situation such as overrun or contact with a stopper, and a smooth restarting operation can be realized. Moreover, two Hall ICs 37a and 37b suffice for the number of sensors required for that purpose, so that the number of sensors can be reduced and the product cost can be reduced.
[0045]
The present invention is not limited to the above embodiment, and it goes without saying that various modifications can be made without departing from the scope of the invention.
For example, in the above-described embodiment, a case has been described in which the motor is applied to a wiper device of an automobile. However, the present invention is not limited to this, and the motor can be used for other vehicle electric components such as a power window, a home appliance, and the like. It is. In the present embodiment, both wiper arms are driven by individual motors 7a and 7b, respectively. However, the present invention employs a type in which both wiper arms 1a and 1b are operated by a single motor and a link mechanism. Also applicable to Furthermore, in the above-described embodiment, the case where the present invention is applied to the parallel wiping type wiper device has been described, but the present invention is also applicable to the opposite wiping type wiper device (opposite type). The magnetic poles (N, S) of the ring-shaped sensor magnet 41 may be reversed. In this case, the magnetic poles detected by the Hall ICs 37a and 37b are reversed from those shown in FIGS.
[0046]
【The invention's effect】
According to the control method of the wiper device of the present invention, the position of the wiper arm is detected based on when the wiper arm is at the reference position, and the wiper arm is reciprocated between the upper reversing position and the lower reversing position. In the case where the wiper arm is stopped between the upper reversing position and the lower reversing position during operation, the wiper arm is always started toward the reference position when restarting. Even if the vehicle stops abnormally between the lower turning positions, it always passes the reference position at the time of restart, and the position of the wiper arm can be accurately grasped. Therefore, it is possible to prevent the blade from overrunning at the time of restarting, and to prevent the mechanical component from abutting against the stopper, thereby improving the wiping feeling.
[0047]
According to the wiper device of the present invention, when the wiper arm is on the upper reversing position side with respect to the reference position, both the first and second magnetic detection elements face the second magnetic pole (for example, the S pole), and the wiper arm is inverted with respect to the reference position. At least one of the first and second magnetic detection elements is provided with a sensor magnet facing the first magnetic pole (for example, N pole) when it is on the position side, so the first and second magnetic poles in the first and second magnetic detection elements are provided. , It can be determined whether the wiper arm is on the upper reversing position side or the lower reversing position side with respect to the reference position. Thereby, even when the wiper arm is abnormally stopped between the upper reversing position and the lower reversing position due to power cutoff or the like, the wiper arm can always be started in the reference position direction at the time of restart, and the wiper arm can be started by the two magnetic detecting elements. The position can be accurately grasped. Therefore, the number of magnetic sensing elements can be reduced, and the cost of the device can be reduced.
[Brief description of the drawings]
FIG. 1 is an explanatory view schematically showing a wiper device using an electric motor with a speed reduction mechanism as a drive source according to an embodiment of the present invention.
FIG. 2 is a sectional view showing the structure of the electric motor of FIG.
FIG. 3 is a partially cutaway sectional view showing a meshing state of the worm gear shown in FIG. 2;
FIG. 4 is an explanatory diagram showing a relationship between a Hall IC and a sensor magnet.
FIG. 5 is a table showing combinations of magnetic poles detected by a Hall IC at each control point.
[Explanation of symbols]
1a, 1b Wiper arm
2a, 2b Wiper blade
3 Windshield
4a, 4b Wiper shaft
5 Wiping range
6 Storage
7a, 7b Electric motor with reduction mechanism
8 Motor body
9 Speed reduction mechanism
10 Motor housing
10a Open end
10b bottom
11 Casing
11a Bearing
11b gear chamber
11c Communication unit
12,13 permanent magnet
14 Amateur
15 Rotation axis
15a Tip
16,17 bearing
18 Amateur Core
19 Amateur Coil
20 commutator
20a trunk
20b commutator piece
21 Brush holder
22 brushes
24 Wiring
25 Power supply terminal
26 wall
27,28 warm
29,30 Warm wheel
31 Worm gear
32,33 pinion gear
34 output shaft
35 Drive gear
36 Printed circuit board
37a, 37b Hall IC
38,39 Hall IC
40 connection terminal
41 Sensor magnet
42 multi-pole magnetized magnet
A Lower inversion position
B Top inversion position
C Storage position
O Origin position

Claims (10)

A method for controlling a wiper device that detects a position of a wiper arm as a base point when the wiper arm is at a reference position and performs a reciprocating wiping operation of the wiper arm between an upper inverted position and a lower inverted position,
When the wiper arm is stopped between the upper reversing position and the lower reversing position during operation, the wiper arm is always started toward the reference position when restarting. 2. The control method for a wiper device according to claim 1, wherein the wiper arm has a storage position below the lower reversing position, and when the wiper arm stops at a position other than the storage position during operation, the wiper arm is restarted. A method for controlling a wiper device, wherein the wiper arm is always started toward the reference position. A motor body having a rotating shaft, and a wiper device driven by an electric motor with a speed reducing mechanism having a speed reducing mechanism that reduces the rotation of the rotating shaft and transmits the output to an output shaft,
A wiper arm connected to the output shaft and performing a reciprocating wiping operation between an upper reversing position and a lower reversing position;
A first magnetic detection element arranged to face a predetermined position of the output shaft when the wiper arm is at a reference position, and a second magnetic detection element arranged at a position separated by a predetermined angle from the first magnetic detection element When,
A first magnetic pole and a second magnetic pole provided on the output shaft and having different polarities from each other along a circumferential direction, wherein the first and second magnetic detections are performed when the wiper arm is on the upper reversing position side with respect to the reference position. A sensor magnet in which at least one of the first and second magnetic detection elements is opposed to the first magnetic pole when the elements are both opposed to the second magnetic pole and the wiper arm is on the lower inversion position side with respect to the reference position; A wiper device comprising: The wiper device according to claim 3, wherein the first magnetic detection element faces a boundary between the first magnetic pole and the second magnetic pole when the wiper arm passes through the reference position. 5. The wiper device according to claim 3, wherein when the wiper arm is at the lower reversing position, both the first and second magnetic detecting elements face the first magnetic pole. The wiper device according to any one of claims 3 to 5, wherein the wiper arm has a storage position below the lower inversion position, and the first magnetic detection element when the wiper arm is at the storage position. Is opposed to the first magnetic pole, and the second magnetic detecting element is opposed to the second magnetic pole. The wiper device according to any one of claims 3 to 6, wherein, when the wiper arm is stopped between the upper reversing position and the lower reversing position during operation, the wiper arm is always at the reference position when restarting. A wiper device characterized in that the wiper device starts to move toward. 7. The wiper device according to claim 6, wherein, when the wiper arm stops at a position other than the storage position during operation, the wiper arm always starts toward the reference position when restarting. The wiper device according to any one of claims 3 to 8, wherein the wiper device further includes a sensor that detects a rotation angle of the rotation shaft, and the wiper arm is set at a reference point when the wiper arm is at the reference position. A wiper device for starting detection of a rotation angle of a rotation shaft. An electric motor with a reduction mechanism having a motor body having a rotation shaft, and a reduction mechanism for transmitting rotation to the output shaft by reducing the rotation of the rotation shaft,
A first magnetic detection element disposed at a reference position where a predetermined portion of the output shaft faces when the output shaft is in a predetermined state, and a second magnetic detection element disposed at a position separated by a predetermined angle from the first magnetic detection element A detection element;
A first magnetic pole and a second magnetic pole provided on the output shaft and having different polarities along a circumferential direction, wherein the first and second magnetic detections are performed when the output shaft is in one direction with respect to the reference position. A sensor magnet in which at least one of the first and second magnetic detecting elements is opposed to the first magnetic pole when both of the elements are opposed to the second magnetic pole and the output shaft is on the other side with respect to the reference position; An electric motor with a speed reduction mechanism, comprising:

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