JPH11348734A - Wiper link device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform wiping in the same wiping range even in both low/high speed modes, by providing a switching mechanism which can change an eccentric position of an eccentric metal member relating to a pivotal support shaft by a rotational direction of a motor arm. SOLUTION: An eccentric metal member is turned at 180 degrees by a switching mechanism 30 because a motor arm 2 is started to rotate at a high sped when a low speed mode is changed to a high speed mode. A first pivot arm 7 and similarly a second pivot arm 11 through a first link connecting rod 6 and a second link connecting rod 10 are turned, respectively, to reciprocate between third/fourth reversing positions, a wiper blade wipes a wiping surface at a high speed corresponding to the first/second pivot arms 7, 11 changing a turning range narrowed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiper link device for converting rotation of a motor arm into reciprocating rotation of a pivot shaft by a link connecting rod.

[0002]

2. Description of the Related Art As a wiper link device for converting rotation of a motor arm into reciprocating rotation of a pivot shaft by a link connecting rod, a motor arm is fixed to an output shaft provided in the wiper motor, and fixed to an end of the motor arm. The ball retainer fixed to one end of the link connecting rod is fitted to the ball pin via a spherical pair, and a pivot arm rotatably connected to the other end of the link connecting rod is rotatably supported by the vehicle body panel. Is known, in which a wiper blade is attached to a pivot shaft via a wiper arm.

In such a wiper link device, the rotation of the motor arm is converted into reciprocating rotation of a pivot arm via a link connecting rod, and the reciprocating rotation of the pivot arm causes the pivot shaft to reciprocate. Wiping the wiping surface back and forth.

[0004]

However, in the above-mentioned wiper link device, the kinetic energy given in the high-speed mode is larger than the kinetic energy given in the low-speed mode. As a result, the wiping range wiped by the wiper blade in the high-speed mode is larger than the wiping range wiped by the wiper blade in the low-speed mode. Therefore, in the high-speed mode, if the length of each link is determined according to the wiping range in which the wiper blade does not interfere with the molding on the side of the windshield glass, the wiping may be left in the low-speed mode. There was a problem that was bad.

[0005]

An object of the present invention is to provide a wiper link device according to the present invention.
It is an object of the present invention to provide a wiper link device that can perform wiping in the same wiping range in both the low-speed mode and the high-speed mode.

[0006]

Configuration of the Invention

[0007]

According to a first aspect of the present invention, there is provided a wiper link device, wherein the motor arm rotates in a first rotation direction while rotating in a second rotation direction, and is disposed on the motor arm. A pivot shaft, an eccentric metal member rotatably supported by the pivot shaft with an outer diameter center eccentric to the center of the pivot shaft, and a rotation center concentric with the eccentric metal member. A retainer externally rotatably fitted thereto, a link connecting rod having the retainer fixed at one end, a pivot arm rotatably coupled to the other end of the link connecting rod, and a pivot fixed to the pivot arm and having a wiper blade attached thereto. A switching mechanism that can change the eccentric position of the eccentric metal member with respect to the pivot shaft according to the rotation direction of the shaft and the motor arm. To have.

In the wiper link device according to a second aspect of the present invention, a motor arm that rotates in a first rotational direction while rotating in a second rotational direction, a pivot shaft disposed on the motor arm, An eccentric metal member rotatably supported by the pivot shaft with an outer diameter center eccentric to the center of the pivot shaft; and a rotation center concentric with the eccentric metal member, rotatably fitted to the eccentric metal member. A retainer, a link connecting rod having the retainer fixed to one end thereof, a pivot arm rotatably coupled to the other end of the link connecting rod, a pivot shaft fixed to the pivot arm and having a wiper blade attached thereto, and a motor arm. When rotating in the first rotation direction, the eccentric metal member can be arranged eccentrically with respect to the pivot shaft so as to shorten the length of the motor arm, and When the motor arm is rotated in the second rotation direction, a switching mechanism is provided which is capable of disposing the eccentric metal member eccentrically with respect to the pivot shaft so as to return the length of the motor arm. And

In the wiper link device according to a third aspect of the present invention, the switching mechanism includes a locking plate capable of rotating the eccentric metal member supported by the pivot shaft by a predetermined angle range. It is characterized by having a configuration.

In the wiper link device according to a fourth aspect of the present invention, the switching mechanism is formed on the first and second locking portions respectively formed on the locking plate and a part of the eccentric metal member. The locking plate is characterized in that the locking plate includes a locking portion that is locked to the first and second locking portions.

[0011]

In the wiper link device according to the first aspect of the present invention, the switching mechanism is used when the motor arm rotates in the first rotation direction and when the motor arm rotates in the second rotation direction. The eccentric position of the eccentric metal member is changed. Therefore, if the length of the motor arm is set to be short in the rotation direction of the high-speed mode, and the length of the motor arm is set to be long in the rotation direction of the low-speed mode, the difference in the wiping range is increased in any mode. Will not occur.

In the wiper link device according to the second aspect of the present invention, when the high speed mode is selected and the motor arm rotates in the first rotation direction, the switching mechanism reduces the length of the motor arm so that the length of the motor arm is reduced. The member is arranged eccentrically with respect to the pivot shaft, whereas the switching mechanism restores the length of the motor arm when the motor arm rotates in the second rotational direction by selecting the low speed mode. The eccentric metal member is disposed eccentrically with respect to the pivot shaft. Therefore, there is no difference between the wiping range when the motor arm rotates at a high speed and the wiping range when the motor arm rotates at a low speed.

[0013] In the wiper link device according to a third aspect of the present invention, the motor arm rotates in the first rotation direction by rotating the eccentric metal member with respect to the locking plate by a predetermined angle range. The eccentric position is changed between when the motor arm rotates in the second rotation direction. Therefore, in addition to the effects of claims 1 and 2, the means for determining the eccentric position of the eccentric metal member does not become complicated.

In the wiper link device according to a fourth aspect of the present invention, when the eccentric metal member is rotated by a predetermined angle range with respect to the locking plate, the locking portion of the eccentric metal member is moved to the second position of the locking plate. The eccentric position of the eccentric member is determined by locking to the first locking portion or the second locking portion. Therefore, in addition to the function of claim 3,
The means for eccentrically moving the eccentric metal member does not become complicated.

[0015]

1 to 10 show one embodiment of a wiper link device according to the present invention.

The illustrated wiper link device 1 mainly includes a motor arm 2, a pivot shaft 3, an eccentric metal member 4, a first retainer 5, a first link connecting rod 6, a first pivot arm 7, a first pivot arm 7, It is composed of a pivot shaft 8, a wiper frame 9, a second link connecting rod 10, a second pivot arm 11, a second pivot shaft 12, and a switching mechanism 30, and a wiper motor 13 is fixed to the wiper frame 9.

The wiper motor 13 is a two-speed DC motor, and three brushes (not shown) are electrically connected to a wiper control circuit (not shown). When the low-speed mode is selected, the wiper motor 13 rotates the output shaft 14 forward at a low speed in the counterclockwise direction in FIG. 5 by the wiper control circuit. On the contrary, when the high-speed mode is selected, the wiper control circuit As a result, the output shaft 14 rotates counterclockwise in FIG. 8 at high speed.

As shown in FIG. 2, the motor arm 2 has an output shaft fixing hole 2a at one end and a pivot shaft fixing hole 2b and a pin fixing hole 2c at the other end.
Are formed respectively. In the output shaft fixing hole 2a,
The output shaft 14 provided on the wiper motor 13 is inserted,
The motor arm 2 is fixed to the output shaft 14 by screwing the nut 15 into the output shaft 14 on the output shaft fixing hole 2a. The pivot shaft 3 is inserted into the pivot shaft fixing hole 2 b, and the pivot shaft 3 is crimped and fixed on the lower surface of the motor arm 2. The switching mechanism 30 is provided in the pin fixing hole 2c.
Are inserted. Pivot 3
Has an outer diameter center C1.

When the low-speed mode is selected, the motor arm 2 rotates forward with the output shaft 14 of the wiper motor 13 counterclockwise in FIG.
5, the pivot shaft 3 is rotated at a low speed in the counterclockwise direction in FIG. 5 at a low speed. On the contrary, by selecting the high-speed mode, the output shaft 14 of the wiper motor 13 and the output shaft 14 in the clockwise direction in FIG. Output shaft 14
The pivot shaft 3 is rotated at a high speed in the reverse direction clockwise in FIG.

An eccentric metal member 4 is inserted through the pivot shaft 3. The eccentric metal member 4 is formed in a barrel shape. The eccentric metal member 4 has a pivot shaft having an inner diameter slightly larger than the outer diameter of the pivot shaft 3 as shown in FIG. A support hole 4a is formed. On the lower surface of the eccentric metal member 4, a locking projection 4b, from which the motor arm 2 projects and forms another part of the switching mechanism 30, is formed.

The eccentric metal member 4 is prevented from falling out of the pivot shaft 3 by inserting the pivot shaft support hole 4a into the pivot shaft 3 and fitting the retaining ring 16 to the pivot shaft 3, as shown in FIG. As shown, the pivot shaft 3 is rotatably supported by the pivot shaft 3 with an outer diameter center C2 eccentric by a predetermined eccentric distance L1 with respect to the outer diameter center C1. The outer diameter of the eccentric metal member 4 is 5 to 2 times the eccentric distance L1.
It can be about 0 times.

Outside the eccentric metal member 4, a first retainer 5 is mounted. As shown in FIG.
As shown in the figure, the fitting portion 5 which is slightly larger than the outer diameter of the eccentric metal member 4 inside and has a concave spherical shape is provided.
Since a is formed, it is coupled to the eccentric metal member 4 via a spherical pair. The first retainer 5 is fixed to a first retainer attachment 6a formed at one end of the first link connecting rod 6. The first retainer 5 has an inner diameter center coinciding with the outer diameter center C2 of the eccentric metal member 4.

At the other end of the first link connecting rod 6,
A second retainer mounting portion 6b is formed.
The second retainer 17 is fixed to the retainer mounting portion 6b. A first ball pin 18 fixed to the upper surface of the distal end of the first pivot arm 7 is coupled to the inside of the second retainer 17 via a spherical pair.

The base end of the first pivot arm 7 is
Is fixed to the base end of the pivot shaft 8. First
The pivot shaft 8 is rotatably supported by a first pivot shaft supporting portion 9a formed on the other side of the wiper frame 9, and has a distal end protruding outside a vehicle body panel (not shown). A wiper arm with a wiper blade (not shown) mounted on the outside is screwed.

A second ball pin (not shown) is fixed to the lower surface of the tip of the first pivot arm 7, and the other end of the second link connecting rod 10 is fixed to the second ball pin. A third retainer (not shown) fixed to the second link connecting rod 1 is fitted via a spherical pair.
A fourth retainer 19 fixed to one end of the second pivot arm 11 is fitted to a third ball pin 20 fixed to the distal end of the second pivot arm 11 via a spherical pair.

The proximal end of the second pivot arm 11 is fixed to the proximal end of the second pivot shaft 12. The second pivot shaft 12 is rotatably supported by a second pivot shaft support portion 9 b formed on one side of the wiper frame 9, and has a distal end protruding outside a vehicle body panel (not shown). A wiper arm on which a wiper blade (not shown) is mounted is screwed outside the panel. The wiper frame 9 is formed with a first vehicle body-side fixing portion 9c and a second vehicle body-side fixing portion 9d.
The first and second vehicle body side fixing portions 9c and 9d are screwed to the vehicle body panel. Further, a wiper motor 13 is screwed to the wiper frame 9.

On the other hand, the switching mechanism 30 includes the eccentric metal member 4
And the motor arm 2. The switching mechanism 30 includes a pin 31, a locking projection 4 b formed on the eccentric metal member 4, and a locking plate 32.

As shown in FIG. 4, a holder 32a having an inner diameter slightly larger than the outer diameter of the pivot shaft 3 is formed on the locking plate 32. A fan-shaped rotation range restricting portion 32b is formed on the outside.

The rotation range restricting portion 32b has a first locking portion 32b1 at one end on the outer circumference of the pivot shaft 3.
Are formed, and a second locking portion 32b2 is formed at the other end on the outer circumference of the pivot shaft 3.

The locking plate 32 is formed by inserting the pin 31 into a pin groove 32b3, which is formed substantially in the center of the rotation range restricting portion 32b, with the holder portion 32a inserted through the pivot shaft 3, and the motor 31 is rotated. It is stopped and fixed on the arm 2. At this time, the locking projection 4b of the eccentric metal member 4 inserted into the pivot shaft 3 is
Is disposed between the locking portion 32b1 and the second locking portion 32b2, so that the locking protrusion 4b is formed by the first locking portion 32b1.
Alternatively, the eccentric metal member 4 is rotated within a range until the eccentric metal member 4 is locked to the second locking portion 32b2.

In the switching mechanism 30, the motor arm 2, the first
Link connecting rod 6, first pivot arm 7, first
Pivot shaft 8, second link connecting rod 10,
Second pivot arm 11, second pivot shaft 1
2, the value of the torque T2 generated by the link load and the eccentric distance (eccentric amount) L1 of the eccentric metal member 4 and the pivot shaft support hole 4 of the pivot shaft 3 and the eccentric metal member 4.
The retainer 5 is fitted to a value larger than the sum of the value of the torque T3 generated by the friction between a and the value of the torque T4 generated by the friction between the eccentric metal member 4 and the locking plate 32. The eccentric distance L is adjusted so that the value of the rotational torque T1 generated between the joint portion 5a and the eccentric metal 4 is obtained.
The outer diameter of the eccentric metal member 4 with respect to 1 is selected.

The first function of the switching mechanism 30 is that, when the low-speed mode is selected, while the motor arm 2 is rotating forward at a low speed in the counterclockwise direction in FIG. The locking projection 4b of the metal member 4 is
2, the outer diameter center C2 of the eccentric metal member 4 is separated from the outer diameter center C1 of the pivot shaft 3 by an eccentric distance L1 in a direction away from the output shaft 14 by being locked to the first locking portion 32b1. It is to arrange. As a result, the center of the inner diameter of the first retainer 5 is arranged on the motor arm 2 so as to be offset by the eccentric distance L1 in a direction away from the output shaft 14, so that the first pivot arm is provided through the first link connecting rod 6. 7 is reciprocated between the first reversing position A1 and the second reversing position B1.

The second function of the switching mechanism 30 is that, when the low-speed mode is selected, the low-speed mode is switched to the high-speed mode, so that the motor arm that has rotated forward at a low speed in the counterclockwise direction in FIG. 2 starts reverse rotation at high speed at a high speed from the first reversing position A1 of the first pivot arm 7 at the position a1, as shown in FIG.
In the state, the eccentricity of the eccentric metal member 4 is from the state where the locking projection 4b is locked to the first locking part 32b1 of the locking plate 32 to the position a2, the position a3, the position a4, and the position a5. The locking projection 4b of the metal member 4 is separated from the first locking portion 32b1 of the locking plate 32, and the locking projection 4b of the eccentric metal member 4 is positioned at the position a5.
2 between the second locking portion 32b2 and the position a6, the position a7, the position a8, and the position a9 after the position a5.
2 by the second locking portion 32b2, the outer diameter center C2 of the eccentric metal member 4 is shifted to the outer diameter center C of the pivot shaft 3.
1 is offset from the output shaft 14 in a direction approaching the output shaft 14 by an eccentric distance L1. At this time, the eccentric metal member 4 rotates 180 degrees with respect to the motor arm 2 between the position a1 and the position a5.

The third function of the switching mechanism 30 is that when the high-speed mode is selected, the locking projection 4b of the eccentric metal member 4 engages with the second locking portion 32b2 of the locking plate 32 from the position a5. The output shaft 1 is stopped by moving the outer diameter center C2 of the eccentric metal member 4 from the outer diameter center C1 of the pivot shaft 3 by an eccentric distance L1.
4 to be offset.
As a result, the eccentric distance L1 is set such that the center of the inner diameter of the first retainer 5 approaches the output shaft 14 on the motor arm 2.
8, the first pivot arm 7 is moved from the first reversing position A1 to the second reversing position B1 through the first link connecting rod 6, as shown in FIG.
The third reversal position A is a range narrower than the range consisting of
Between the second reversing position B2 and the fourth reversing position B2.

The fourth function of the switching mechanism 30 is that the high-speed mode is switched to the low-speed mode when the high-speed mode is selected, so that the motor arm 2 that has rotated clockwise and reversely in the clockwise direction in FIG. From the third inversion position A2 in FIG.
When the forward rotation starts at a low speed in the middle clockwise direction, as shown in FIG. 10, the locking projection 4b of the eccentric metal member 4 is locked at the position b1 corresponding to the third reversal position A2.
2 from the state where the second locking portion 32b2 is locked to the position b2, the position b3, the position b4, and the position b5, the locking protrusion 4b of the eccentric metal member 4 is fixed to the locking plate 3.
The second protrusion 32b2 of the eccentric metal member 4 is separated from the second locking portion 32b2 of the second locking portion 32b1 at a position b5, and is locked to the first locking portion 32b1 of the locking plate 32 at a position b5. , Between the position b7, the position b8, and the position b9,
When the locking projection 4b of the eccentric metal member 4 is locked to the first locking portion 32b1 of the locking plate 32, the outer diameter center C2 of the eccentric metal member 4 is shifted from the outer diameter center C1 of the pivot shaft 3. This is to dispose it in a direction away from the output shaft 14 by the eccentric distance L1. At this time, the eccentric metal member 4 rotates 180 degrees with respect to the motor arm 2 between the position b1 and the position b5. Then, through the first link connecting rod 6, the first pivot arm 7 is moved between the first reversing position A1 and the second reversing position B1 in a range larger than the third reversing position A2 and the fourth reversing position B2. It turns back and forth between them. The switching mechanism 30 includes a pin 31, a locking projection 4 b formed on the eccentric metal member 4, and a locking plate 3.
Since it is composed of two, it has no complicated structure, and is therefore easily created.

The wiper link device 1 having such a structure is as follows.
First and second vehicle body side fixing portions 9c, 9 of wiper frame 9
d is screwed to the vehicle body panel, and wiper arms each having a wiper blade mounted on the first and second pivot shafts 8 and 12 projecting outside the vehicle body panel are screwed respectively and mounted on the vehicle body. .

When the low-speed mode is selected, when the motor arm 2 starts rotating at a low speed in the counterclockwise direction in FIG. 5, the center C2 of the outer diameter of the eccentric metal member 4 moves away from the output shaft 14 so that the pivot shaft 3 moves away from the output shaft 14. Eccentric distance L1 from outer diameter center C1
The eccentric metal member 4 rotates while being locked integrally with the motor arm 2 in a state of being offset only by
Pivot arm 7 through link connecting rod 6
However, similarly, the second pivot arm 11 reciprocates between the first reversing position A1 and the second reversing position B1 through the second link connecting rod 10, and the first and second pivot arms 7 move. , 12, the wiper blade wipes the wiping surface at a low speed.

When the low speed mode is changed to the high speed mode,
Since the motor arm 2 starts to rotate clockwise at a high speed from the position a1 in FIG. 7, the eccentric metal member 4 is rotated by 180 degrees by the switching mechanism 30, and the outer diameter center C2 of the eccentric metal member 4 is shifted to the output shaft. 14, the eccentric metal member 4 rotates while being locked integrally with the motor arm 2 in a state where the eccentric metal member 4 is offset by the eccentric distance L1 from the outer diameter center C1 of the pivot shaft 3 in a direction approaching to the first link connecting rod 6. The first pivot arm 7 also reciprocates between the third reversing position A2 and the fourth reversing position B2 through the second link connecting rod 10, and the second pivot arm 11 reciprocates through the second link connecting rod 10, respectively. The wiper blade wipes the wiping surface at high speed corresponding to the first and second pivot arms 7, 12 whose ranges have been changed to be narrow.

When the high speed mode is changed to the low speed mode,
Since the motor arm 2 starts rotating at a low speed in the counterclockwise direction from the position b1 in FIG. 10, the eccentric metal member 4 is rotated by 180 degrees by the switching mechanism 30, and the outer diameter center C2 of the eccentric metal member 4 is output. The eccentric metal member 4 rotates while being locked integrally with the motor arm 2 in a state where the eccentric metal member 4 is offset from the outer diameter center C1 of the pivot shaft 3 in a direction away from the shaft 14 by an eccentric distance L1. 6, the first pivot arm 7 reciprocates between the third reversing position A2 and the fourth reversing position B2, and the second pivot arm 11 reciprocates between the third reversing position A2 and the fourth reversing position B2. The wiper blade wipes the wiping surface at a low speed corresponding to the first and second pivot arms 7 and 12 whose moving ranges have been returned widely.

[0040]

As described above, according to the wiper link device of the first aspect of the present invention, when the motor arm rotates in the first rotation direction, and when the motor arm rotates in the second rotation direction. At the time of rotation, the eccentric position of the eccentric metal member is changed by the switching mechanism. Therefore, if the length of the motor arm is set to be short in the rotation direction of the high-speed mode, and the length of the motor arm is set to be long in the rotation direction of the low-speed mode, the difference in the wiping range is increased in any mode. Will not occur. Therefore, there is an excellent effect that wiping can be performed in the same wiping range in both the low-speed mode and the high-speed mode.

According to the wiper link device of the second aspect of the present invention, when the high-speed mode is selected and the motor arm rotates in the first rotation direction, the switching mechanism shortens the length of the motor arm. The eccentric metal member is disposed eccentrically with respect to the pivot shaft. On the contrary, when the motor arm rotates in the second rotation direction by selecting the low-speed mode, the switching mechanism returns the length of the motor arm. The eccentric metal member is arranged eccentrically with respect to the pivot shaft as described above. Therefore, there is no difference between the wiping range when the motor arm rotates at a high speed and the wiping range when the motor arm rotates at a low speed. Therefore, there is an excellent effect that wiping can be performed in the same wiping range in both the low-speed mode and the high-speed mode.

According to the wiper link device of the third aspect of the present invention, the motor arm is moved in the first rotational direction by rotating the eccentric metal member with respect to the locking plate by a predetermined angle range. The eccentric position is changed between when the motor arm rotates and when the motor arm rotates in the second rotation direction. Therefore, in addition to the effects of the first and second aspects, there is an excellent effect that the means for determining the eccentric position of the eccentric metal member does not become complicated.

According to the wiper link device of the fourth aspect of the present invention, when the eccentric metal member rotates by a predetermined angle range with respect to the locking plate, the locking portion of the eccentric metal member locks the locking plate. The eccentric position of the eccentric member is determined by locking to the first locking portion or the second locking portion. Therefore, in addition to the effect of claim 3,
There is an excellent effect that means for eccentrically moving the eccentric metal member does not become complicated.

[Brief description of the drawings]

FIG. 1 is a front view of an embodiment of a wiper link device according to the present invention.

FIG. 2 is a longitudinal sectional front view around an eccentric metal member in the wiper link device shown in FIG. 1;

FIG. 3 is a cross-sectional view of the eccentric metal member and the retainer shown in FIG. 2;

FIG. 4 is a cross-sectional view of the eccentric metal member and the switching mechanism shown in FIG.

FIG. 5 is a schematic diagram illustrating the operation of the wiper link device shown in FIG.

FIG. 6 is a schematic diagram illustrating the operation of the wiper link device shown in FIG.

FIG. 7 is a schematic diagram illustrating the operation of the wiper link device shown in FIG.

FIG. 8 is a schematic diagram illustrating an operation of the wiper link device shown in FIG.

FIG. 9 is a schematic diagram illustrating the operation of the wiper link device shown in FIG.

FIG. 10 is a schematic diagram illustrating the operation of the wiper link device shown in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 wiper link device 2 motor arm 3 pivot shaft 4 eccentric metal member 4 b (locking portion) locking projection 5 (retainer) first retainer 6 (link connecting rod) first link connecting rod 7 (pivot arm) first Pivot arm 8 (pivot shaft) First pivot shaft 30 Switching mechanism 32 Locking plate 32b1 First locking portion 32b2 Second locking portion

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nobuo Yoshioka 1760 Higashimatano-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture

Claims (4)

[Claims] 1. A motor arm that rotates in a first rotation direction while rotating in a second rotation direction, a pivot shaft disposed on the motor arm, and eccentric with respect to a center of the pivot shaft. An eccentric metal member rotatably supported by the pivot shaft with the outer diameter center defined; a retainer having a rotation center concentric with the eccentric metal member and rotatably fitted to the eccentric metal member; and the retainer. A link connecting rod fixed at one end, a pivot arm rotatably coupled to the other end of the link connecting rod, a pivot shaft fixed to the pivot arm, to which a wiper blade is attached, and a rotation direction of the motor arm. A switching mechanism capable of changing an eccentric position of the eccentric metal member with respect to the pivot shaft. 2. A motor arm that rotates in a first rotation direction while rotating in a second rotation direction, a pivot shaft disposed on the motor arm, and eccentric with respect to the center of the pivot shaft. An eccentric metal member rotatably supported by the pivot shaft with the outer diameter center defined; a retainer having a rotation center concentric with the eccentric metal member and rotatably fitted to the eccentric metal member; and the retainer. A link connecting rod fixed to one end of the link connecting rod, a pivot arm rotatably coupled to the other end of the link connecting rod, a pivot shaft fixed to the pivot arm and having a wiper blade attached thereto, and the motor arm being a first. When rotating in the rotation direction of, the eccentric metal member can be arranged eccentrically with respect to the pivot shaft so as to shorten the length of the motor arm, and When the motor arm rotates in the second rotation direction, a switching mechanism capable of eccentrically disposing the eccentric metal member with respect to the pivot shaft so as to return the length of the motor arm is provided. A wiper link device. 3. The switching mechanism according to claim 1, further comprising a locking plate capable of rotating the eccentric metal member supported by the pivot shaft by a predetermined angle range.
4. The wiper link device according to item 1. 4. The switching mechanism is formed on first and second locking portions respectively formed on the locking plate and a part of the eccentric metal member, and the first and second locking portions of the locking plate are provided. The wiper link device according to claim 3, further comprising a locking portion locked to each of the locking portions.