JP4130578B2 - Wiper device control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control technology for a vehicle wiper device, and more particularly to a technology that is effective when applied to a wiper device that uses a motor driven in the forward and reverse directions as a drive source.
[0002]
[Prior art]
As a drive source of a vehicle wiper device such as an automobile, an electric motor that is operated by a power source such as a battery mounted on the vehicle is used. A reduction mechanism is attached to the electric motor, and the wiper arm swings between an upper reversal position and a lower reversal position using the reduction mechanism as a drive source. In recent years, in order to drive the wiper device in a small space, a method of reciprocating the wiper arm by rotating the motor forward and backward within 180 ° has been put into practical use. In this method, the current position of the wiper arm is detected, and the motor is rotated in the forward and reverse directions in accordance with the position and speed to perform the reversing operation of the wiper arm.
[0003]
In such a wiper system, wiper arm position detection is performed by adding and subtracting the number of pulses generated in conjunction with the rotation of the motor. A multi-pole magnetized magnet is attached to the motor rotation shaft, and a sensor such as a Hall IC that outputs a pulse signal by detecting a change in magnetic pole accompanying the rotation is disposed opposite the magnet. The pulse count is reset at one point (origin position) that serves as a reference for the rotational position of the motor unit output shaft. Then, the motor rotation angle from the reference position is calculated by pulse addition / subtraction from the reset, and the current wiper arm position can be detected by considering the reduction ratio, link ratio, and the like. Further, the motor rotation speed can be detected from the cycle of the motor rotation pulse, and the wiper arm movement speed can also be detected therefrom.
[0004]
On the other hand, at the time of reversing the wiper arm, it is necessary to decelerate the arm speed toward the reversing position in order to suppress the noise generation accompanying the motor forward / reverse rotation. Therefore, in the conventional wiper system, the braking start position is determined using the motor rotation speed (wiper arm moving speed) as a parameter, and the arm speed is controlled to decelerate toward a predetermined reverse position. FIG. 7 is an explanatory diagram showing a speed control mode at the reversal position in the conventional wiper device, where (a) is a map used there, (b) is the relationship between the wiper position and the motor pulse count, and (c) ) Shows the wiper arm operation during reversal.
[0005]
As the speed of the wiper arm increases, the braking start position prior to the reversing operation must be advanced. A map 61 in FIG. 7A shows the relationship between the arm speed and the braking start position. In the map 61, the arm speed is indicated by the pulse period of the motor, and the pulse count number until the wiper arm stops correspondingly, that is, the pulse number between the reverse position and the braking start position is associated with it. . For example, if the motor speed is S ₀ when the wiper arm 62 reaches the position A shown in FIG. 7C, the pulse count number until the arm stops is calculated as K ₀ from the map 61. Then, the brake is applied at a position P just before the pulse count number K ₀ from the upper reversal position. As a result, the wiper arm 62 decelerates toward the upper reverse position and smoothly stops at the reverse position.
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-264776
[Problems to be solved by the invention]
However, the load of the wiper arm 62 is not always constant depending on the state of attachment of water drops, snow, dust, etc., and between the pulse count number assumed by the map 61 due to load fluctuation and the pulse count number until the arm actually stops. There may be differences. That is, the arm is less likely to stop when the load is lighter than expected, but may stop more quickly when the load is high. For example, when the load is large, although the brake is started at the position P, the wiper arm 62 may stop at the position B earlier than expected. On the contrary, when the load is small, the wiper arm 62 does not stop easily and may move to the position C. In other words, variations in the stop position at the reverse position occur due to load fluctuations, especially at high speed / low load or at low speed / high load, the deviation from the number of pulses shown on the map increases, and overrun or unachieved stop status There was a problem that the possibility of the occurrence of this would increase.
[0008]
An object of the present invention is to suppress variations in the stop position of the wiper arm at the reverse position.
[0009]
[Means for Solving the Problems]
Control method of the wiper apparatus of the present invention, by an electric motor and a control method of the wiper apparatus for a reciprocating wiping operation between an upper reversal position and lower reversal position wiper arm, before Symbol least one of the two reversing positions a braking position determination is provided on the vicinity of the calculated braking start position based on the speed and load of the wiper arm in the brake determination position, the wiper arm comprises, from the calculated said braking start position in the two reversing positions deceleration It is controlled.
[0010]
In the present invention, unlike the case where the braking start position is determined solely based on the speed, the braking start position corresponding to the current situation is set based on the speed and load of the wiper arm. That is, when the load is small even at the same speed, braking can be started quickly and a sufficient braking time can be secured, while when the load is large, the braking time can be limited accordingly. For this reason, the wiper arm can be stopped at a predetermined reverse position regardless of the speed and load state, and an overrun at the reverse position and a stop before the reverse position can be prevented. Therefore, it is possible to suppress variations in the arm stop position at the reversal position, the wiping range is stabilized, and the usability is improved.
[0011]
In the control method of the wiper device, the speed of the wiper arm may be detected based on a motor pulse period output as the electric motor rotates. Further, the electric motor may be pulse-driven by a pulse width modulation method, and the load of the wiper arm may be detected based on a ratio between the ON time and OFF time of the pulse. Further, in the control method of the wiper device, the braking start position of the wiper arm may be determined by a map using the speed and load of the wiper arm as parameters.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory view showing a configuration of a wiper device to which a control method according to an embodiment of the present invention is applied. FIG. 2 is a cross-sectional view showing a structure of an electric motor used in the wiper device of FIG. FIG. 3 is a partially cutaway sectional view showing a meshed state of a worm gear inside the electric motor of FIG. 2.
[0013]
The wiper device shown in FIG. 1 has a wiper arm 1a on the passenger seat side and a wiper arm 1b on the driver's seat side that are swingably provided on the vehicle body. A wiper blade 2a on the passenger seat side is attached to the wiper arm 1a (see FIG. 6). Similarly, a wiper blade is attached to the wiper arm 1b. The wiper blades 2a and 2b are in elastic contact with the windshield by a spring member (not shown) incorporated in the wiper arms 1a and 1b. Two wiper shafts 3a and 3b protrude from the vehicle body, and the wiper arms 1a and 1b are attached to the wiper shafts 3a and 3b, respectively, at their base ends.
[0014]
The wiper blades 2a and 2b are swung away from rain and snow attached to the windshield by swinging and moving between the lower inversion position and the upper inversion position, that is, the wiping range 4 indicated by the solid line in the figure. . The wiper blades 2a and 2b are moved to the storage position located below the lower inversion position and stored in the storage unit when the wiper is stopped. The storage portion is provided inside the hood of a vehicle body (not shown).
[0015]
In order to swing the wiper arms 1a and 1b, the wiper device is provided with a link mechanism 6 that uses an electric motor 5 with a speed reduction mechanism (hereinafter abbreviated as a motor 5) as a drive source. The link mechanism 6 is housed inside the hood of the vehicle body, and only the tip portions of the wiper shafts 3a and 3b protrude outside the vehicle body. The wiper shafts 3a and 3b are rotatably accommodated in pivot holders 52a and 52b having attachment portions 51 to the vehicle body, respectively. A support pipe 53 is attached between the pivot holders 52a and 52b. A motor bracket (not shown) is attached to the center of the support pipe 53, and the motor 5 is fixed to the motor bracket.
[0016]
At the lower part of the pivot holders 52a and 52b, swing plates 54a and 54b fixed to the lower ends of the wiper shafts 3a and 3b are attached. The swing plates 54 a and 54 b are connected by a connecting rod 55, and both plates 54 a and 54 b swing in synchronization with the rotation of the motor 5. One end of a drive rod 56 is attached to the swing plate 54a. The other end of the drive rod 56 is rotatably attached to a link plate 57 fixed to the output shaft 34 of the motor 5.
[0017]
When the motor 5 is controlled to rotate forward and backward and the output shaft 34 rotates forward and backward, the link plate 57 swings in the direction indicated by the arrow X in FIG. When the link plate 57 swings, the swing plate 54a also swings by an angle X in the direction of the arrow. When the swing plate 54a is operated, the swing plate 54b connected by the connecting rod 55 also swings at an angle X in synchronization. Since the plates 54a and 54b are fixed to the wiper shafts 3a and 3b, the wiper shafts 3a and 3b rotate as the plates swing. As a result, the wiper arms 1a and 1b fixed to the wiper shafts 3a and 3b swing and the reciprocating wiping operation by the wiper blades 2a and 2b is performed.
[0018]
As shown in FIG. 2, the motor 5 includes 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 has a bearing portion 11a, a gear chamber 11b, and a communication portion 11c that are formed in a cylindrical shape having substantially the same dimensions as the motor housing 10. 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 portion 11a of the casing 11 are in contact with each other.
[0019]
Two permanent magnets 12 and 13 are provided on the inner peripheral surface of the motor housing 10 so that different magnetic poles face each other, and a magnetic field is formed inside the motor housing 10. Inside the motor housing 10, an armature 14 is provided 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 portion 10 b and the bearing portion 11 a of the motor housing 10.
[0020]
The amateur 14 has an amateur core 18 in which a plurality of slots are formed. Each slot is wound with a copper wire to form an amateur coil 19. A commutator 20 is attached to the left side of the amateur core 18 in the figure. The commutator 20 includes a resin body portion 20a fixed to the rotating shaft 15, and a plurality of commutator pieces 20b arranged radially on the outer periphery thereof. Each commutator piece 20 b is connected to the armature coil 19.
[0021]
A brush holder 21 is provided inside the bearing portion 11a. Two brushes 22 and 23 are attached to the brush holder 21. The brushes 22 and 23 are biased toward the commutator piece 20b, and contact the commutator piece 20b in this state. The communication unit 11 c is provided with a power supply terminal 25 connected to the brushes 22 and 23 by wiring 24. By supplying current to the power supply terminal 25 from a control unit (not shown), reverse currents are supplied to the brushes 22 and 23, respectively.
[0022]
Since the amateur coil 19 is located in the magnetic field, when a rectified current is passed 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 armature coil 19, the rotation angle, rotation direction or rotation speed of the rotating shaft 15 can be controlled.
[0023]
A rotating shaft 15 protrudes inside the gear chamber 11b. The distal end portion 15a of the rotating shaft 15 is located in the vicinity of the wall surface 26 located on the opposite side of the gear chamber 11b from the motor body 8. As shown in FIG. 3, two worms 27 and 28 are formed on the outer peripheral surface located inside the gear chamber 11 b of the rotating shaft 15. Inside the gear chamber 11b, two worm wheels 29, 30 are provided so as to mesh with the worms 27, 28 to constitute a worm gear 31. The worm wheels 29 and 30 are respectively provided with pinion gears 32 and 33 coaxially. The pinion gears 32 and 33 mesh with a drive gear 35 as a rotating body formed integrally with the output shaft 34 of the speed reduction mechanism 9. The rotation of the rotary shaft 15 is decelerated by the worm gear 31, the pinion gears 32 and 33, and the drive gear 35 and transmitted to the output shaft 34.
[0024]
As described above, the output shaft 34 of the motor 5 is mechanically coupled to the wiper shafts 3a and 3b, respectively. The wiper shafts 3a and 3b rotate integrally with the output shaft 34. When the rotary shaft 15 rotates, the worms 27 and 28 receive a thrust force acting in the axial direction of the rotary shaft 15 by the worm wheels 29 and 30. At this time, since each of the worms 27 and 28 is formed in the opposite direction, the thrust force acts in the opposite direction. Thereby, the movement of the rotating shaft 15 in the thrust direction is suppressed, and it is not necessary to provide a thrust bearing or the like on the rotating shaft 15. In the present embodiment, a two-stage reduction mechanism including the worm gear 31, the pinion gears 32 and 33, and the drive gear 35 is used as the reduction mechanism 9. However, the present invention is not limited to this, and a one-stage reduction mechanism using only the worm gear is used. Or a planetary gear mechanism may be used.
[0025]
A printed circuit board 36 is attached to the wall surface 26 of the casing 11 perpendicular to the rotation shaft 15. A connection terminal 40 located in the communication unit 11c is attached to the printed circuit board 36. From the connection terminal 40, power supply from a control unit (not shown) and transmission of a detection signal are performed. On the printed circuit board 36, two Hall ICs 37 for absolute position detection as first sensors and Hall ICs 38 and 39 for relative position detection as second sensors are attached. 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 are used. Also good.
[0026]
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 member to be detected of the Hall IC. As a member to be detected of the Hall IC 37 for absolute position detection, a magnet 41 is attached to an outer peripheral portion on the lower side in the drawing of the side surface of the drive gear 35. The magnet 41 rotates together with the drive gear 35. In addition, as a member to be detected of the Hall ICs 38 and 39 for detecting the relative position, a multipolar magnetized magnet 42 (hereinafter abbreviated as a magnet 42) is attached to the tip portion 15 a of the rotating shaft 15. The magnet 42 rotates integrally with the rotary shaft 15 and is magnetized with 6 poles in the rotation direction.
[0027]
The Hall IC 37 for absolute position detection is attached at a position facing the magnet 41 when the magnet 41 is at the reference position of the output shaft 34, that is, when the wiper arms 1a and 1b attached to the wiper shafts 3a and 3b are in the lower inverted position. Yes. Therefore, when the wiper arms 1a and 1b are in the lower inverted position, the Hall IC 37 transmits a pulse signal to a control unit (not shown) connected to the connection terminal 40, and it is detected that the wiper arms 1a and 1b are in the lower inverted position. The In the present embodiment, the magnet 41 is provided at a position where the wiper arms 1a, 1b are at the lower inversion position. However, the present invention is not limited to this, and the wiper arms 1a, 1b may be provided at an upper inversion position or a storage position. . Further, a plurality of magnets 41 may be provided at a plurality of different positions such as an upside down position.
[0028]
The Hall ICs 38 and 39 are mounted on the surface of the printed circuit board 36 at positions facing the magnet 42 with a phase shifted by 90 ° with respect to the rotation direction of the magnet 42. When the rotating shaft 15 rotates, the Hall ICs 38 and 39 output pulses (motor pulses) for six cycles per rotation of the rotating 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 this pulse. Further, since the phases of the Hall ICs 38 and 39 are shifted by 90 °, the appearance order of the pulses transmitted from the Hall ICs 38 and 39 differs depending on the rotation direction of the rotary shaft 15. Therefore, the rotation direction of the rotating shaft 15 can be detected by the appearance order of the pulses. Further, the rotational speed of the rotary shaft 15 can be detected by the period of the pulses detected by the Hall ICs 38 and 39.
[0029]
In the motor 5, 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, respectively. The motor 5 is pulse-driven by a pulse width modulation (PWM) method, and the amount of supplied current is controlled by the ratio (Duty) of the ON time and OFF time of the pulse. The number of rotations of the motor 5 is constantly monitored using motor pulses, and ON duty of the pulses is feedback PID controlled according to the load. That is, when the load increases and the rotational speed decreases, the duty is increased and the ON time increases, and when the load decreases and the rotational speed increases, the duty is decreased and the ON time decreases.
[0030]
The current supplied to the brushes 22 and 23 is rectified by the commutator 20, and the current flows through the armature coil 19. This electric current generates a rotational force in the armature coil 19 and the rotating shaft 15 rotates. The rotation of the rotary shaft 15 is decelerated by the worm gear 31, the pinion gears 32 and 33, and the drive gear 35 of the speed reduction mechanism 9 and transmitted to the output shaft 34. When the output shaft 34 rotates, the wiper shafts 3a and 3b rotate accordingly, and the wiper arms 1a and 1b operate.
[0031]
In such a wiper device, when the wiper arms 1a and 1b approach the upside down position, deceleration control is performed toward the upside position as in the conventional wiper device. FIG. 4 is a map used for speed control of the wiper arm in the vicinity of the reversal position, FIG. 5 is an explanatory diagram showing the relationship between the wiper position and the motor pulse count, and FIG. 6 is an explanatory diagram showing the wiper arm operation during reversal.
[0032]
A map 58 in FIG. 4 shows the relationship between the speed of the wiper arms 1a and 1b, the load of the motor 5 and the braking start position. In the map 58, the speed of the wiper arms 1a and 1b and the load of the motor 5 are used as parameters, and both parameters and the pulse count number until the wiper arms 1a and 1b stop, that is, the reverse position and the braking start position. The number of pulses between them is related. The map 58 is prepared with three types of maps for upper inversion, lower inversion, and storage.
[0033]
In the map 58, the speed of the wiper arms 1a and 1b is indicated by the motor pulse period of the motor 5. As described above, the rotation of the rotary shaft 15 of the motor 5 is transmitted to the wiper shafts 3a and 3b through the speed reduction mechanism 9 and the link mechanism 6 at a predetermined speed reduction ratio. That is, there is a correlation between the rotation speed of the motor 5 and the speed of the wiper arms 1a and 1b. Therefore, if the motor rotation speed is grasped by the motor pulse period, the arm speed can be grasped therefrom.
[0034]
On the other hand, the load of the motor 5 is indicated by PWM control duty for the motor 5. As described above, the motor 5 is PWM-controlled, and the ON duty of the pulse is feedback-controlled according to the load. That is, the duty is controlled according to the magnitude of the load, and the current load state of the motor 5 can be grasped by looking at this.
[0035]
As described above, the map 58 defines the braking start position in a form that is one-dimensionally increased as compared to the map of FIG. Therefore, even if the arm speed is the same, the value indicating the braking start position changes if the load is different. For example, when the speed (motor pulse cycle) of the wiper arms 1a and 1b is S ₀ , the pulse count is K ₁ when the motor load is L ₁ , but the load L ₂ (L ₁ <L ₂ is larger). ) pulse count becomes K ₂ in the case of.
[0036]
Therefore, if the motor speed is S ₀ when the wiper arm 1a reaches the braking determination position A shown in FIG. 6, the braking start position is determined using the map 58 from the motor load at that time. As described above, the load pulse count if L ₁ is K _1, the number of pulses counted if the load is an L ₂ becomes K _2. Here, K ₁ is larger than K ₂ (K ₁ > K ₂ ). In the case of K ₁ , the position X _{1 in} FIG. 6 is braked, and in the case of K ₂ , the position X ₂ is braked. This is the starting position. That is, when the motor load is small (L ₁ ), the brake is applied from a position (X ₁ ) farther from the reverse position.
[0037]
Accordingly, when the load is small even at the same speed, braking is started quickly and sufficient braking time is secured. On the other hand, when the load is large, the braking time is limited accordingly. That is, in this control method, unlike the case where the braking start position is determined solely based on the speed, the braking start position suitable for the current situation is set by the speed and load of the wiper arms 1a and 1b. For this reason, the wiper arms 1a and 1b can be stopped at a predetermined reversal position regardless of the state of speed and load, and an overrun at the reversal position or a stop before the reversal position can be prevented. Therefore, it is possible to suppress variations in the arm stop position at the reversal position, the wiping range is stabilized, and the usability is improved.
[0038]
It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.
For example, in the above-described embodiment, the method of controlling the braking start position using the map of FIG. 4 at the upside down position and the storage position has been described. Alternatively, the control method can be applied only to the storage position. In the wiper device, a single motor 5 and a link mechanism 6 actuate both wiper arms 1a and 1b. However, the wiper device is also applicable to a wiper device in which both wiper arms are driven by individual motors. it can. Furthermore, although the case where the present invention is applied to a parallel wiping type wiper apparatus has been described in the above-described embodiment, the present invention can also be applied to an opposing wiping type wiper apparatus (opposite type).
[0039]
【The invention's effect】
According to the control method of the wiper device of the present invention, since the braking start position of the wiper arm is calculated based on the speed and load of the wiper arm, unlike the case where the braking start position is simply determined only by the speed, A braking start position suitable for the situation is set. For this reason, the wiper arm can be stopped at a predetermined reverse position regardless of the speed and load state, and an overrun at the reverse position and a stop before the reverse position can be prevented. Therefore, it is possible to suppress variations in the arm stop position at the reversal position, the wiping range is stabilized, and the usability is improved.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a configuration of a wiper device to which a control method according to an embodiment of the present invention is applied.
2 is a cross-sectional view showing a structure of an electric motor used in the wiper apparatus of FIG. 1. FIG.
3 is a partially cutaway sectional view showing a meshed state of a worm gear inside the electric motor of FIG. 2. FIG.
4 is a map used for speed control of a wiper arm in the vicinity of a reverse position in the wiper device of FIG. 1;
FIG. 5 is an explanatory diagram showing a relationship between a wiper position and a motor pulse count in the wiper device of FIG. 1;
6 is an explanatory diagram showing a wiper arm operation at the time of reversal in the wiper device of FIG. 1. FIG.
7A and 7B are explanatory diagrams showing a speed control mode at a reversal position in a conventional wiper device, in which FIG. 7A is a map used there, FIG. ) Shows the wiper arm operation during reversal.
[Explanation of symbols]
1a, 1b Wiper arm 2a, 2b Wiper blade 3a, 3b Wiper shaft 4 Wiping range 5 Electric motor 6 Link mechanism 8 Motor body 9 Reduction mechanism 10 Motor housing 10a Open end 10b Bottom part 11 Casing 11a Bearing part 11b Gear chamber 11c Communication part 12, 13 Permanent Magnet 14 Amateur 15 Rotating Shaft 15a Tip 16 and 17 Bearing 18 Amateur Core 19 Amateur Coil 20 Commutator 20a Body 20b Commutator Piece 21 Brush Holder 22 Brush 24 Wiring 25 Power Terminal 26 Wall 27, 28 Worm 29, 30 Warm Wheel 31 Worm gear 32, 33 Pinion gear 34 Output shaft 35 Drive gear 36 Printed circuit board 37 Hall IC
38,39 Hall IC
40 connecting terminal 41 magnet 42 multipolar magnetized magnet 51 mounting portion 52a, 52b pivot holder 53 support pipe 54a, 54b plate 55 connecting rod 56 drive rod 57 link plate 58 map 61 map 62 wiper arm A braking judgment position X ₁ braking start position X ₂ braking start position

Claims (4)

A method for controlling a wiper device that reciprocally wipes a wiper arm between an upper reverse position and a lower reverse position by an electric motor,
Provided with a braking position determination in one vicinity of at least one of the previous SL both inverted position, to calculate the braking start position based on the speed and load of the wiper arm in the braking position determination,
The wiper arm is a control method of the wiper apparatus characterized by being deceleration control toward the both inverted position from the calculated the brake starting position.   2. The method of controlling a wiper apparatus according to claim 1, wherein the speed of the wiper arm is detected based on a motor pulse period output as the electric motor rotates.   3. The method of controlling a wiper device according to claim 1, wherein the electric motor is pulse-driven by a pulse width modulation method, and the load of the wiper arm is detected based on a ratio between the ON time and the OFF time of the pulse. A method for controlling a wiper device.   The wiper device control method according to any one of claims 1 to 3, wherein the braking start position of the wiper arm is determined by a map using the speed and load of the wiper arm as parameters. Control method of the device.

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