JP6051122B2 - Wiper device - Google Patents

Description

  The present invention relates to a wiper device that reciprocates a wiper with torque of an electric motor.

  2. Description of the Related Art Conventionally, a wiper device is provided in order to wipe off a windshield of a vehicle and secure a field of view, and examples of the wiper device are described in Patent Documents 1, 2, and 3. The wiper device described in Patent Document 1 has a structure called a so-called opposite type. In this wiper device, the torque of a single electric motor is transmitted to two wipers via a link mechanism.

  The wiper device described in Patent Document 2 has a so-called dual type structure, and the wiper device has a first electric motor and a second electric motor, and the torque of the first electric motor is the first link. The torque is transmitted to the first wiper via the mechanism, and the torque of the second electric motor is transmitted to the second wiper via the second link mechanism.

  The wiper device described in Patent Document 3 has a structure called a dual direct type, and the wiper device has a first electric motor and a second electric motor, and the torque of the first electric motor is a link mechanism. The torque of the second electric motor is transmitted to the second wiper without going through the link mechanism.

JP 2007-182154 A JP 2009-1113569 A French Patent Application Publication No. 2965232

  The wiper devices described in Patent Documents 1 and 2 have high performance for removing foreign substances because the torque of the electric motor can be amplified by the link mechanism and transmitted to the wiper. On the other hand, the wiper devices described in Patent Documents 1 and 2 increase the number of parts and increase the arrangement space by providing the link mechanism.

  Since the wiper device described in Patent Document 3 is not provided with a link mechanism, the number of components is small and the arrangement space is small. However, since the wiper device described in Patent Document 3 is not provided with a link mechanism, the torque transmitted from the electric motor to the wiper cannot be amplified. For this reason, the wiper device described in Patent Document 3 does not have sufficient performance for removing foreign matter.

  In the wiper device described in Patent Document 3, the output torque of the electric motor can be set high. However, the torque transmission mechanism that transmits the torque of the electric motor to the wiper, specifically, the durability of the meshing portion between the worm formed on the rotor shaft of the electric motor and the gear formed on the worm wheel is reduced. It was not practical because another problem occurred.

  The objective of this invention is providing the wiper apparatus which can improve the wiping performance of a wiper and can suppress that the durability of a torque transmission mechanism falls.

The present invention is a wiper device that transmits the torque of an electric motor to a wiper via a torque transmission mechanism, and reciprocates the wiper to wipe the wiping surface of an object. The wiper reciprocates the wiper a plurality of times. The first control for setting the torque of the electric motor to a first value and reciprocating the wiper, and the torque for the electric motor set to a second value different from the first value. wherein a second control to reciprocate the wiper, have a torque control unit for switches, the torque control unit, and said second control and the first control switches for each reciprocation number of the wiper, reciprocation number of the wiper to perform the first control, Ru der reciprocation number of times or more of the wiper to perform the second control.
The present invention is a wiper device that transmits the torque of an electric motor to a wiper via a torque transmission mechanism, and reciprocates the wiper to wipe the wiping surface of an object. The wiper reciprocates the wiper a plurality of times. The first control for setting the torque of the electric motor to a first value and reciprocating the wiper, and the torque for the electric motor set to a second value different from the first value. A torque control unit that switches and performs second control for reciprocating the wiper, and the torque control unit performs the first control to reciprocate the wiper between an upper reversal position and a lower reversal position. If the wiper does not reach the lower inversion position during operation, the first control and the second control are switched .

  In the present invention, the torque transmission mechanism includes a worm formed on a rotor shaft of the electric motor, and a worm wheel formed with a gear meshing with the worm.

  The present invention includes an output shaft that is provided coaxially with the worm wheel and rotates integrally with the worm wheel, and the wiper reciprocates between an upper reversing position and a lower reversing position about the output shaft. Operate.

  In the present invention, the torque control unit makes the first value different from the second value by 5 Nm or more.

  In the present invention, the torque control unit switches between the first control and the second control when there is snow on the wiping surface when the wiper is reciprocated by performing the first control. Do it.

  In the present invention, when the torque control unit performs the first control to reciprocate the wiper, and there is snow on the wiping surface, the second control is performed without performing the first control. I do.

  The present invention is provided with a plurality of snow detection sensors for detecting snow in the vicinity of the lower inversion position of the wiping surface.

  ADVANTAGE OF THE INVENTION According to this invention, the wiping performance of a wiper can be improved and the fall of durability of a torque transmission mechanism can be suppressed.

It is a conceptual diagram of the vehicle which has the wiper apparatus of this invention. It is a top view which shows the drive mechanism of FIG. It is a block diagram which shows the control system of the wiper apparatus of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a wiper device 12 for wiping a windshield 11 of a vehicle 10. The wiper device 12 includes a wiper 12A on the passenger seat side and a wiper 12B on the driver seat side. A wiper 12A is arranged on the left side when the vehicle 10 is viewed from the front, and a wiper 12B is arranged on the right side. Since the wiper 12A and the wiper 12B have a bilaterally symmetric structure when the vehicle 10 is viewed from the front, in the following description, one wiper 12A will be described.

  The wiper 12 </ b> A includes a wiper arm 14 and a wiper blade 24 attached to the wiper arm 14. A drive mechanism 13 for operating the wiper 12A is also provided. As shown in FIG. 2, the drive mechanism 13 includes an electric motor 16 provided in the motor housing 15 and a worm wheel 18 provided in the gear case 17.

  The electric motor 16 has a rotor shaft 19, and a worm 20 is formed on the outer periphery of the rotor shaft 19. A portion of the rotor shaft 19 where the worm 20 is formed is disposed inside the gear case 17. A gear 21 is formed on the outer periphery of the worm wheel 18, and the gear 21 and the worm 20 are engaged with each other. An output shaft 22 coaxial with the worm wheel 18 is provided, and the worm wheel 18 and the output shaft 22 are supported so as to rotate integrally. One end of the output shaft 22 is exposed to the outside of the gear case 17.

  On the front side of the windshield 11, a metal or resin cowl cover 23 is provided. The cowl cover 23 is disposed along the edge of the windshield 11 in the width direction of the vehicle 10. The drive mechanism 13 is provided below the cowl cover 23, and the tip of the output shaft 22 is disposed above the cowl cover 23. Here, the upper direction represents the outer direction of the vehicle 10, and the lower direction represents the inner direction of the vehicle 10.

  The wiper arm 14 is connected to a portion of the output shaft 22 disposed above the cowl cover 23. The wiper arm 14 is directly connected to the output shaft 22, and no link mechanism is provided. Therefore, the wiper 12A can swing, that is, reciprocate within a predetermined range around the output shaft 22. That is, the output shaft 22 serves as a pivot shaft. When the wiper 12A reciprocates, the wiper blade 24 wipes the wiping surface of the windshield 11, that is, the surface. Note that the operating range of the wiper 12 </ b> A is determined by the rotation angle of the electric motor 16.

  A control board 25 is provided below the gear case 17, and the control board 25 is covered with a cover. FIG. 3 shows a control system of the electric motor 16, and the control board 25 has a controller 27 that supplies electric power of the power source 26 mounted on the vehicle 10 to the electric motor 16. The controller 27 is an element that controls the rotation, stop, rotation direction, and torque of the electric motor 16. The controller 27 corresponds to the torque control unit of the present invention.

  The controller 27 is a known controller having an inverter circuit, a PWM control circuit, a current detection circuit, a storage circuit, and the like. The inverter circuit includes a switching element that controls energization and de-energization of the coil of the electric motor 16. The controller 27 processes the signal input from the detection unit 28 and performs determination and control based on the processing result of the signal. The detection unit 28 includes a wiper switch 28A operated by the driver, a rotation sensor 28B that detects the rotation speed and rotation angle of the rotor shaft 19, a snow accumulation amount on the upper surface of the windshield 11, and a snow accumulation detection sensor 28C that detects the presence or absence of snow accumulation. including.

  The wiper 12B is configured similarly to the wiper 12A, and a drive mechanism 13 for driving the wiper 12B is provided separately from the drive mechanism 13 for the wiper 12A. The drive mechanism 13 that drives the wiper 12B is configured similarly to the drive mechanism 13 that drives the wiper 12A. The control system for driving the wiper 12B is configured in the same manner as the control system for driving the wiper 12A. Accordingly, the wiper 12A and the wiper 12B can be driven separately. As described above, the wiper device 12 has a so-called dual type structure, and the wiper device 12 includes the electric motor 16 that operates the wiper 12A and the electric motor 16 that operates the wiper 12B separately.

  Next, the operation and control of the wiper device 12 will be described. When the wiper switch is turned off, the wipers 12A and 12B are stopped at a predetermined initial position. When the wiper 12 </ b> A is stopped at the initial position, the wiper blade 24 is in contact with the upper surface of the cowl cover 23.

  On the other hand, the wiper switch is turned on to supply the electric power of the power source 26 to the electric motor 16 and the direction of the current with respect to the coil of the electric motor 16 is switched so that the rotor shaft 19 is within a predetermined rotation angle range. Rotate forward and backward. The torque of the rotor shaft 19 is transmitted to the output shaft 22 via the worm wheel 18. The worm 20 and the gear 21 function as a speed reduction mechanism that reduces the rotational speed of the worm wheel 18 with respect to the rotational speed of the rotor shaft 19 when transmitting the torque of the rotor shaft 19 to the output shaft 22.

  When the worm wheel 18 rotates forward and backward, the torque of the output shaft 22 is transmitted to the wiper 12A, and the wiper 12A reciprocates between a predetermined lower inversion position A1 and upper inversion position B1. The windshield 11 is wiped away. Here, the lower inversion position A1 and the upper inversion position B1 can be grasped as the operation position of the wiper blade 24 with the output shaft 22 as the center, for example.

  On the other hand, the wiper 12B also reciprocates between a predetermined lower inversion position and upper inversion position, and the windshield 11 is wiped by the wiper blade 24. During operation of the two wiper arms 14, when the wiper arm 14 reaches the lower reversal position, the rotation direction, rotation speed, and rotation of the two electric motors 16 are such that the wiper 12B is positioned above the wiper 12A. Control the angle. Thereafter, when the wiper switch is turned off, the torque of the electric motor 16 is controlled so that the wiper 12A stops at the initial position. The lower inversion position A1 is between the stop position and the upper inversion position B1.

  The wiper device 12 continuously rotates the wiper 12A a plurality of times between the lower inversion position A1 and the upper inversion position B1, with the lower inversion position A1 as a reference, between the time when the wiper switch is turned on and the time when it is turned off. It can be reciprocated. Further, the wiper device 12 can change the torque of the electric motor 16 for each reciprocating motion of the wiper 12A. Specifically, low torque control that sets the torque of the electric motor 16 to a predetermined value and high torque control that sets a torque higher than the low torque control can be executed. This controls the duty ratio of the switching element provided in the controller 27 to control the current value supplied to the coil and change the torque of the electric motor 16.

  The torque of the electric motor 16 in the low torque control can be set to 20 Nm, for example, and the torque of the electric motor 16 in the high torque control can be set to 30 Nm, for example. The torque of the electric motor 16 at the time of low torque control and the torque of the electric motor 16 at the time of high torque control are preferably different from each other by 5 Nm or more. This takes into account the control error of the output torque of the electric motor 16.

  If the reciprocating operation of the wiper 12A twice is regarded as one cool and the wiper 12A is continuously reciprocated, the low torque control is executed when the wiper 12A is reciprocated once, and the wiper 12A is operated once. High torque control can be performed when reciprocating. When the wiper 12A is reciprocated three times in one cool, low torque control can be executed when the wiper 12A is reciprocated twice, and high torque control can be executed when the wiper 12A is reciprocated once. . High torque control is first wiping control, and low torque control is second wiping control.

  Further, when the wiper 12A is reciprocated four times in one cool, the low torque control can be executed when the wiper 12A is reciprocated three times, and the high torque control can be executed when the wiper 12A is reciprocated once. In addition, when performing low torque control several times within 1 cool, after performing low torque control continuously, you may perform high torque control. Further, when the low torque control is executed a plurality of times within one cool, the low torque control may be executed after the high torque control is executed. Further, the number of reciprocating operations of the wiper 12A that executes the low torque control can be made equal to or more than the number of reciprocating operations of the wiper 12A that executes the high torque control.

  Further, when the low torque control is executed a plurality of times within one cool, the high torque control and the low torque control may be executed alternately. That is, when the wiper 12A is continuously reciprocated a plurality of times, the high torque control is executed every predetermined number of reciprocating operations. Thus, in a plurality of cools, the frequency ratio between the number of executions of high torque control and the number of executions of low torque can be changed for each cool. Thus, the wiper device 12 can vary the torque of the electric motor 16 in the predetermined reciprocating operation of the wiper 12A and the torque of the electric motor 16 in the reciprocating operation different from the predetermined reciprocating operation. .

  Here, the torque set in the low torque control and the torque set in the high torque control correspond to the first value and the second value of the present invention. It should be noted that the first value and the second value may be torques different from each other, either high torque or low torque. For example, the low torque control corresponds to the first control of the present invention, and the high torque control corresponds to the second control of the present invention.

  By the way, the torque of the electric motor 16 is not always controlled to be constant in the process in which the wiper 12A reciprocates once. For example, the torque of the electric motor 16 can be reduced immediately before the wiper 12A reaches the lower inversion position A1. Further, the torque of the electric motor 16 can be increased when the wiper 12A operates toward the upper reversal position B1 immediately after reversing at the lower reversal position A1.

  For this reason, the torque of the electric motor 16 set by the low torque control and the torque of the electric motor 16 set by the high torque control are the maximum when the wiper 12A operates from the upper reverse position B1 to the lower reverse position A1. It includes values defined by torque, average torque when the wiper 12A reciprocates once, and the like.

  Thus, the torque transmitted to the wiper 12A can be controlled by regularly switching and setting the torque of the electric motor 16 for each reciprocation of the wiper 12A. If there is snow on the windshield 11, the snow is wiped off by the wiper blade 24 and pressed near the cowl cover 23. If the torque transmitted from the electric motor 16 to the wiper 12A is increased, the force with which the wiper blade 24 presses snow is increased even if the amount of snow on the cowl cover 23 is increased. Accordingly, it is possible to suppress the range in which the wiper 12A performs the wiping operation from being narrowed, and it is possible to secure the field of view.

  For this reason, the continuous operation time of the wiper 12A can be made as long as possible. The continuous operation time is, for example, from the state where the lower reversal position A1 of the wiper 12A is at the reference position, the lower reversal position A1 of the wiper 12A starts to rise above the snow load, and the limit position C1 of 20 degrees with respect to the reference position. Means the time to reach The reference position is the lower inversion position A1 of the wiper 12A in a state where there is no snow. That is, it is possible to suppress a decrease in the angle of the range in which the wiper 12A performs the wiping operation around the output shaft 22 between the lower inversion position A1 and the upper inversion position B1.

  Further, according to the wiper device 12 of the present embodiment, the torque transmitted from the electric motor 16 to the wiper 12A is not always controlled to a high torque, and a high torque and a low torque are alternately output from the electric motor 16. . That is, the frequency, ratio, time, etc., at which the torque of the electric motor 16 becomes high torque can be reduced as much as possible. Therefore, it is possible to reduce the load on the meshing portion between the worm 20 and the gear 21 and to suppress the durability of the rotor shaft 19 and the worm wheel 18 from being lowered.

  That is, it is possible to increase the number of wiping operations of the wiper 12A, that is, the number of reciprocations performed as much as possible after the operation of the wiper 12A until the durability of the rotor shaft 19 and the worm wheel 18 decreases. Furthermore, since the wiper 12A is attached to the output shaft 22 without a link mechanism, an increase in the number of parts can be suppressed, and the arrangement space of the drive mechanism 13 can be narrowed. Therefore, the layout property of the wiper device 12, the in-vehicle property, and the degree of freedom of vehicle body design are improved.

  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, the lower inversion position and the upper inversion position can be grasped as the operation position of the wiper arm with the output shaft as the center. The controller can also detect the amount of snow on the upper surface of the windshield based on a signal input from the snow detection sensor, and can perform control according to the amount of snow. Control according to the amount of snow is to change the frequency ratio between the low torque control and the high torque control according to the amount of snow, to change the torque of the electric motor in the high torque control according to the amount of snow, etc. Including.

  Further, the high torque control and the low torque control may be performed by both of the two wipers, or may be performed only by the electric motor that operates the lower wiper when the reversal position is reached. Furthermore, the torque of the electric motor can be changed to three or more stages in addition to two stages of high torque and low torque.

  Furthermore, first, the default control, that is, the low torque control is performed as a normal control. If the wiper does not return from the upper reverse position to the lower reverse position even after the low torque control is performed, the high torque control is performed. It may be. That is, the high torque control is not always performed, but the high torque control is performed only when snow accumulates in the wiping operation range and the wiper cannot return to the lower inversion position. Thereby, wear of a gear and a decrease in durability can be suppressed. At this time, as in the above embodiment, the low torque control and the high torque control may be switched every time the wiper reciprocates, or only the high torque control is performed regardless of the number of reciprocations of the wiper. Also good.

  Furthermore, a snow cover detection sensor may be provided at each of a plurality of positions in the vicinity of the lower inversion position and separated in the vehicle width direction. Then, the controller determines that there is snow when all of the plurality of snow detection sensors detect snow. Further, the controller determines that there is no snow when less than the total number of snow detection sensors detect snow, and further determines that an obstacle other than snow is in the vicinity of the lower inversion position. Then, the controller performs the low torque control without performing the high torque control when an obstacle other than snow is in the vicinity of the lower inversion position. In this way, the wiper device prevents gear wear and deterioration of durability by performing low torque control when an obstacle other than snow that cannot be compressed is in the downward inversion position.

  Furthermore, the present invention provides a structure in which the lower reversal position of the wiper disposed on the right side when the vehicle is viewed from the front is set below the lower reversal position of the wiper disposed on the left side when the vehicle is viewed from the front. Is also applicable. In this case, the controller performs low torque control and high torque control when controlling the torque of the electric motor that drives the wiper disposed on the right side when the vehicle is viewed from the front.

  Furthermore, in the above-described embodiment, an example has been described in which snow is pressed and hardened when the wiper reaches the lower reversal position, and the operation range of the wiper is suppressed from being narrowed. If the control of this embodiment is performed, if snow has accumulated in the vicinity of the front pillar of the vehicle, the snow can be compacted when the wiper reaches the upper reversal position. Therefore, it is possible to prevent the operation range of the wiper from being narrowed.

  Further, the object to be wiped with the wiper includes the rear glass of the vehicle in addition to the windshield of the vehicle. Moreover, the foreign material wiped off by the wiper includes mud, dust, dead leaves and the like in addition to snow. Furthermore, the torque transmission mechanism of the present invention includes a worm wheel and a rotor shaft. The torque transmission mechanism of the present invention includes a structure in which another gear is interposed between the rotor shaft and the worm wheel.

DESCRIPTION OF SYMBOLS 10 ... Vehicle 11 ... Windshield 12 ... Wiper apparatus 12A, 12B ... Wiper 13 ... Drive mechanism 14 ... Wiper arm 15 ... Motor housing 16 ... Electric motor 17 ... Gear case 18 ... Worm wheel 19 ... Rotor shaft 20 ... Worm 21 ... Gear 22 ... Output shaft 23 ... Cowl cover 24 ... Wiper blade 25 ... Control board 26 ... Power supply 27 ... Controller 28 ... Detection unit 28A ... Wiper switch 28B ... Rotation sensor 28C ... Snow cover detection sensor A1 ... Lower inversion position C1 ... Limit position B1 ... Upper inversion position

Claims (8)

A wiper device that transmits the torque of an electric motor to a wiper via a torque transmission mechanism and reciprocates the wiper to wipe the wiping surface of an object,
The first control for reciprocating the wiper by setting the torque of the electric motor to a first value when the wiper is reciprocated a plurality of times is different from the first value. and a second control to reciprocate the wiper is set to a second value, have a torque control unit for switches,
The torque control unit switches between the first control and the second control for each number of reciprocating operations of the wiper,
Reciprocation number of the wiper to perform the first control, Ru der reciprocation number of times or more of the wiper to perform the second control, the wiper device. A wiper device that transmits the torque of an electric motor to a wiper via a torque transmission mechanism and reciprocates the wiper to wipe the wiping surface of an object,
The first control for reciprocating the wiper by setting the torque of the electric motor to a first value when the wiper is reciprocated a plurality of times is different from the first value. A torque control unit configured to switch and perform a second control for setting the second value and reciprocating the wiper;
The torque control unit performs the first control to reciprocate the wiper between an upper reversing position and a lower reversing position, and when the wiper does not reach the lower reversing position, cormorant line by switching first control and said second control, the wiper device. The wiper device according to claim 1 or 2,
The torque transmission mechanism is closed and a worm formed in the rotor shaft of the electric motor, and a worm wheel gear meshing with the worm is formed, a wiper device. The wiper device according to claim 3 , wherein
An output shaft provided coaxially with the worm wheel and rotating integrally with the worm wheel;
The wiper, reciprocated between an upper reversal position and lower reversal position about said output shaft, the wiper device. The wiper device according to any one of claims 1 to 4,
The torque control unit, said first value and said second value Ru varied over 5 Nm, the wiper device. In the wiper device according to any one of claims 1 to 5,
When the torque control unit performs the first control to reciprocate the wiper, and there is snow on the wiping surface , the wiper performs switching between the first control and the second control. apparatus. In the wiper device according to any one of claims 1 to 5 ,
The torque control unit performs the second control without performing the first control when there is snow on the wiping surface when the wiper is reciprocated by performing the first control. apparatus. The wiper device according to claim 2 or 4 ,
A wiper device , wherein a plurality of snow accumulation detection sensors for detecting snow accumulation are provided in the vicinity of the lower inversion position of the wiping surface .

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