JPH04306152A - Position detection device for use in wiper device - Google Patents

Abstract

PURPOSE:To enable a position detection device for detecting the position of a wiper in a wiper device to detect the position of the wire even when a link mechanism forming the wire device is integrated with a position detecting function. CONSTITUTION:In a wiper device wherein a wiper arm is drivingly connected via a link mechanism 3 to a connecting pin 17 provided on one side face of a gear 10 rotated by a motor 5 and a wiper is put in a reciprocating movement, a magnet 29 comprising N, S poles alternately formed therein is provided on the outer peripheral portion of the side face of the gear 10 and a hole element 33 for detecting the N, S poles is disposed on the outside of the magnet 29 opposite to the N, S poles.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiper device, and more particularly to a position detection device for detecting the position of a wiper in a wiper device.

0002

2. Description of the Related Art A conventional position detection device for a wiper device is known, for example, as shown in British Patent No. 1,522,523. As shown in FIGS. 8 to 10, the position detection device in this wiper device includes a ring-shaped metal plate 71 formed on the top surface of a gear 70 provided on a drive motor (not shown), and a convex portion on the outer periphery. The portions 72 are formed at equal intervals. Further, on the upper surface of the gear 70, a magnet 73 is disposed on the convex portion 72 of the metal plate 71, and a Hall element 74 is disposed at the lower part of the gear 70, facing the magnet 73. . The magnetic force from the magnet 73 is sensed by the Hall element 74 via the convex portions 72. Therefore, in order to drive the wiper of the wiper device,
When the gear 70 rotates, the magnetic force from the magnet 73 is blocked by the protrusion 72 or passes through it, so the Hall element 7
4 can sense the magnetic force of the magnet 73 transmitted through the convex portion 72. The Schmitt trigger system 75 then forms a square wave based on this magnetic force signal. The position of the wiper in the wiper device can be detected based on this square wave.

0003

[Problem to be solved by the invention] However, in recent years,
As more and more parts are being mounted in the engine compartment, the engine compartment is becoming overcrowded. Therefore, the mounting space is inevitably reduced or restricted. In order to cope with these problems and improve the workability of assembling it into the vehicle, the wiper device and the drive motor are integrated, that is, the housing of the drive motor is assembled into the housing of the link mechanism that makes up the wiper device. Consideration has been given to integrating the wiper device and the position detection device.

However, when the link mechanism is provided on the upper and lower surfaces of the gear 70, the magnetic force of the magnet 73 is blocked by the operation of the link mechanism.
4 cannot accurately receive the magnetic force passing through from the convex portion 72. Therefore, there is a problem that the position of the wiper of the wiper device cannot be detected accurately.

The present invention has been made to solve the above problems, and its purpose is to provide a wiper device that can detect the wiper position even if the link mechanism constituting the wiper device and the position detection are integrated. An object of the present invention is to provide a position detecting device for use in a vehicle.

[0006]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a method in which a link rotation pin of a rotating body rotated by a motor is mounted at a position offset from the rotation axis of the rotating body. , in a wiper device in which the link rotation pin is drivingly connected to a wiper arm via a link mechanism to reciprocate the wiper, two different
The gist of the invention is to provide a detected body formed by alternately forming detected parts of seeds, and to arrange a detection sensor for detecting the detected part on the outside facing the detected part of the detected body. do.

[0007]

[Operation] When the motor is driven and the rotating body rotates, a link rotation pin provided at a position offset from the rotation axis of the rotating body rotates, and the link mechanism operates. The operation of this link mechanism causes the wiper arm to rotate. At this time, since the detected object rotates in the same way, the detection sensor alternately detects two different detected parts of the detected object, thereby detecting the amount of rotation of the rotating object, that is, the amount of rotation of the wiper arm. can do.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a position detection device for a wiper device embodying the present invention will be described below with reference to FIGS. 1 to 3. As shown in FIG. 2, a housing 4 in which a link mechanism 3 of a wiper device 2 is housed is attached and fixed to the side of the body 1 on the windshield side in an engine compartment (not shown). Further, a motor 5 is installed at the bottom of the housing 4.
are attached and fixed in one piece. The output shaft 6 of the motor 5 is inserted into the housing 4 and is rotatably inserted and supported by a support piece 7 integrally formed within the housing 4 via a bearing 8 . Further, a worm 9 is formed at the tip of the output shaft 6.

Next, the structure of the link mechanism 3 will be explained. The side part of the output shaft 6 in the housing 4 (
On the left side in FIG. 2), a gear 10 made of resin and serving as a rotating body that meshes with the worm 9 is rotatably disposed. That is, as shown in FIG.
A bearing 1 is mounted on a cylindrical portion 12 integrally formed perpendicular to the bearing 1.
The base end of the rotation shaft 14 is inserted through the shaft 3 and is rotatably supported. The gear 10 is fixed to the tip of the rotating shaft 14. Further, as shown in FIG. 2, a cross-shaped fixing plate 15 is provided on the upper surface of the gear 10.
is provided, and a claw portion 16 formed on the fixed plate 15
is inserted into the gear 10. Therefore, the gear 10
and the fixed plate 15 rotate together.

Further, a connecting pin 17 as a link rotation pin is fixed to a portion of the fixed plate 15 (a portion other than the center of the fixed plate 15) so as to protrude toward the upper surface. One end of a swing link 35 is rotatably connected to the connecting pin 17. On the other hand, a pivot shaft 1 is provided on the side of the output shaft 6 in the housing 4 (on the left side in FIG. 2) so as to be perpendicular to the output shaft 6.
8 are arranged. That is, the pivot shaft 18 is rotatably supported relative to the housing 4 by a pair of bearings 19 and 20 provided between the housing 4 and the pivot shaft 18. And the pivot shaft 1
A distal end portion of the housing 4 protrudes from the housing 4, and a wiper arm (not shown) is connected and fixed to this distal end portion.

[0011] Also, the pivot shaft 1 in the housing 4
A connecting lever 21 having a supporting piece 21a having a forked tip is fixed to the base end of the connecting lever 8. Moreover, the connecting lever 21
The tip of the swing link 35 is connected by a connecting pin 22 between the supporting pieces 21a. Therefore, when the motor 5 is driven and the output shaft 6 and the worm 9 rotate, the gear 10 and the connecting pin 17 that are meshed with the worm 9 rotate. Due to the rotation of this connecting pin 17, the swing link 35
The connecting lever 21 can be reciprocated in the direction shown by the arrow. As a result, the pivot shaft 18 fixed to the connecting lever 21 is reciprocated by the connecting lever 21, so that the wiper arm (not shown) connected and fixed to the pivot shaft 18 can be reciprocated.

Further, a circular holding plate 23 fixed to the gear 10 is provided on the lower surface of the gear 10. This retaining plate 23 has an insertion portion 25 protrudingly formed thereon to be inserted into a recess 24 on the back surface of the gear 10, and a stepped portion 26.
A large-diameter portion 27 is formed through. Moreover, the large diameter portion 2
A flange 28 is formed to protrude from the outer peripheral edge of 7. Furthermore, a ring-shaped magnet 29 as an object to be detected is provided in the large diameter portion 27 of the holding plate 23 and comes into contact with the flange 28.
is fixed with adhesive. The ring-shaped magnet 29 is shown in FIG.
As shown in , the magnetic pole as the detected part is placed along the outer circumferential surface.
In other words, N poles and S poles alternate (in this example, the total number is 50
pole).

A circular guide plate 30 fixed to the holding plate 23 is disposed on the lower surface of the holding plate 23. This guide plate 30 has a protruding step portion 31 that is inserted into the back surface of the insertion portion 25 of the holding plate 23, and a guide piece 32 that supports the flange 28 of the holding plate 23. Furthermore, the housing 4
A Hall element 33 as a detection sensor is arranged and fixed on the outer peripheral side of the magnet 29 inside, and outputs a detection signal based on a change in the magnetic pole of the magnet 29. That is, when the gear 10 and the magnet 29 are rotated by the motor 5, the magnetic pole on the side of the Hall element 33 changes. This allows the amount of rotation of the gear 10 to be detected.

[0014] Also, the Hall element 33 is connected to the controller 3.
4, and outputs an output signal based on the change in the magnetic pole of the magnet 29. The controller 34 determines the position of the wiper arm connected to the pivot shaft 18 based on the number of magnetic pole changes. In other words, pivot axis 1
When the wiper arm connected to 8 is located at the set position, a counter in the controller 34 becomes 0. The counter of the controller 34 is set to become 0 every time the total number of magnetic poles of the magnet 29 is 50. Further, when the count number of the counter in the controller 34 reaches 24, the controller 3
4, it is determined that the wiper arm is located at an inverted position in which it reciprocates.

Further, when the count number of the counter is in the range from 0 to 24, it is determined that the pivot shaft 18 is rotating in the direction in which the wiper arm moves from the set position to the reverse position,
In the range from 25 to 48, it is determined that the pivot shaft 18 is rotating in the direction in which the wiper arm moves from the reverse position to the set position. Next, the operation of the position detection device configured as described above will be explained.

When the motor 5 is driven, the output shaft 6 and the worm 9 rotate, so the gear 1 meshed with the worm 9 rotates.
0 rotates. As a result, the base end of the swing link 35 connected to the connecting pin 17 of the fixed plate 15 rotates. Since the swing lever 21 connected to the tip of the swing link 35 reciprocates in the direction of the arrow, the pivot shaft 18 rotates by a predetermined amount, allowing the wiper arm to reciprocate.

Furthermore, due to the rotation of the gear 10, the holding plate 23
Since the ring-shaped magnet 29 rotates, the Hall element 33 disposed on the side of the magnet 29 detects a change in the magnetic pole due to the rotation of the magnet 29. Then, the controller 34 counts the detection signal detected by the Hall element 33, and based on the counted number, it is possible to determine how far the pivot shaft 18 and the wiper arm are rotated and at what position.

For example, the controller 34
3 detection signals, and if the count is 24 or less, the controller 34 determines that the wiper arm is heading to the reverse position where it reciprocates on the window, and when the count reaches 24, the controller 34: It is determined that the wiper arm is in an inverted position where it reciprocates on the window. Furthermore, if the count is 25 or more, the controller 34 determines that the wiper arm is moving from the window reversal position to the set position.

Therefore, if sensors are provided on both sides of the gear 10 as in the prior art, the amount of rotation of the gear 10 cannot be accurately detected because the swing link 35 obstructs the light from the sensor. However, in this embodiment, the change in the magnetic pole of the magnet 29 is controlled by a Hall element 33 provided on the outer periphery of the magnet 29.
is detected, so even if the gear 10 is provided with a member constituting the link mechanism 3 such as the swing link 35, the gear 1
It is possible to accurately detect the rotation amount of 0 and accurately detect the position of the wiper arm.

In particular, when the wiper devices 2 are provided corresponding to a pair of wiper arms, the controller 34 controls the gear 10 in each wiper device 2.
The amount of rotation of the wiper arm can be detected by the Hall element 33, and the amount of rotation of the wiper arm can be easily detected. As a result, the wiper device can be controlled by the controller 34 so that the blades of the wiper arms do not interfere with each other.

In this embodiment, the gear 10 and the holding plate 2
3, and the amount of rotation of the gear 10 is detected by the Hall element 33 on the outer periphery of the magnet 29.
As shown in FIG. 4, the outer periphery of the lower surface of the magnet 29 is alternately magnetized with N and S poles, and the magnet is disposed on the lower surface of the guide plate 30 fixed to the lower part of the gear 10. And magnet 2
It is also possible to arrange the Hall element 33 on the outer periphery of the lower surface of the magnet 29 so as to detect the N pole and S pole of the magnet 29.

Furthermore, as shown in FIGS. 5 and 6, the guide plate 30
It is also possible to provide an electrode plate 36 on the lower surface of the wiper arm, and form a position detection section 37 on the electrode plate 36 for detecting the set position (home position) of the wiper arm. As a result,
By providing the brush 38 in sliding contact with the electrode plate 36, it is possible to reliably determine whether or not the wiper arm is in the set position using the brush 38 in sliding contact with the electrode plate 36.

Furthermore, as shown in FIG. 7, it is also possible to provide a magnet 29 on the top surface of the gear 10, detect changes in the magnetic pole of the magnet 29 using a Hall element 33, and detect the amount of rotation of the gear 10. Further, instead of the Hall element 33, a magnetoresistive element, a reed switch, or the like may be used to detect a change in the magnetic pole.

[0024]

As described in detail above, according to the present invention, there is an excellent effect that the wiper position can be detected even if the link mechanism constituting the wiper device and the position detection are integrated.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a wiper device according to the invention.

FIG. 2 is a cross-sectional plan view of the wiper device.

FIG. 3 is a plan view showing a magnet.

FIG. 4 is a perspective view showing another example in which a Hall element detects a change in the magnetic pole on the lower surface of a magnet fixed by a guide plate.

FIG. 5 is a perspective view showing another example in which an electrode plate is provided on the lower surface of the guide plate and position detection is performed using a brush that slides in contact with the electrode plate.

FIG. 6 is a plan view showing a state in which an electrode plate is provided on the lower surface of the guide plate.

FIG. 7 is a perspective view showing another example in which a magnet is arranged on the upper surface of a gear.

FIG. 8 is an explanatory diagram of a conventional gear in which a metal plate is provided on the top surface.

FIG. 9 is an explanatory diagram showing a state in which a magnet is provided on the upper surface of the gear and a Hall element facing the magnet is provided on the lower surface of the gear.

FIG. 10 is an electrical block diagram showing that a signal detected by a Hall element is converted into a square wave by a Schmitt trigger system.

[Explanation of symbols]

3... Link mechanism, 5... Motor, 10... Gear as a rotating body, 17... Connection pin as a link rotation pin, 29... Magnet as a detected object, 33... Hall element as a detection sensor, N, S... Target Pole as a detection part

Claims (1)

[Claims] Claim 1: A link rotation pin of a rotating body rotated by a motor is attached at a position offset from the rotation axis of the rotating body, and the link rotation pin drives a wiper arm via a link mechanism. In the wiper device in which the wiper is connected to each other and is configured to rotate the wiper back and forth, a detected body is provided in which two different types of detected parts are alternately formed on the outer circumference of the rotating body, and A position detection device for a wiper device, characterized in that a detection sensor for detecting the detected portion is disposed on the outside facing the detection portion.