JPH0513659Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a wiper drive device, and particularly relates to an improvement of a fixed position stop device for wipers, and is applicable to vehicles such as automobiles that drive in snowy areas. The present invention relates to a wiper drive device installed in

[Conventional technology]

In general, in wiper drive devices installed in vehicles such as automobiles, in order to ensure safe driving, even if the hand switch is turned off at random, the wiper drive device moves the wiper blade to the lower corner of the window and then stops automatically. A position stop device is provided.

This type of conventional fixed position stop device attaches a conductive plate having a non-conductive part to the end face of the drive gear,
Together with this conductive plate, the contacts that constitute the switch that opens and closes the electric circuit of the motor are arranged in the housing so that the conductive plate slides as the drive gear rotates, even if the hand switch is turned off at random. , the conductive plate and the contacts form an electric circuit up to a fixed position, and at the fixed position, the main circuit is interrupted by the non-conductive part of the conductive plate, the armature circuit is short-circuited, and an electric brake is applied to start the wiper motor. It is configured to stop automatically.

[Problem that the invention attempts to solve]

However, in a wiper drive device equipped with such a fixed position stop device, when an external force is applied to the drive gear in the direction opposite to the forward rotation, such as when snow is shoveled at the bottom of the window, the conductive plate Since a chattering phenomenon occurs in which conduction and non-conduction are repeated between the contact point and the contact point, there is a problem in that this portion deteriorates due to heat generation and the durability decreases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a wiper drive device that can solve the problems of the prior art and prevent chattering.

By the way, the present applicant has developed a wiper drive device that can prevent the chattering phenomenon by providing a clutch member rotatably so as to rotate together with the biasing direction of the drive gear, and installing a conductive plate between the clutch member and the housing. By interposing a switch that opens and closes the electric circuit of the motor, the clutch member rotates the conductive plate and the contacts relative to each other as the drive gear rotates. When an external force is applied to reverse the rotation of the drive gear, we have developed a clutch that prevents the relative backtracking between the conductive plate and the contact without causing it to follow the reverse rotation of the drive gear. (Publication of Utility Model Application No. 61-21657 and
60-77390).

A second object of the present invention is to further improve this wiper drive device.

[Means for solving problems]

The wiper drive device according to the present invention is equipped with a fixed position stop device that stops the wiper arm 10 at a predetermined position even when the wiper switch 30 is opened at random, and this fixed position stop device drives the wiper arm 10. It is interposed between the housing 1 and the drive gear 12 driven by the motor 31 for the purpose of conductive plate 2
5 and the conductive plate 25 and the non-conductive portion 26 by sliding on the circular annular orbit of the conductive plate 25 and the non-conductive portion 26 as the drive gear 12 rotates.
and a movable contact piece 16 constituting a switch 28 for opening and closing the electric circuit of the motor 31. When the wiper switch 30 is opened at random, the conductive plate 25 and the movable contact piece 16 In the wiper drive device, the switch 28 is closed until a predetermined position, and the switch 28 is opened when the movable contact piece 16 comes into contact with the non-conductive part 26 at the predetermined position. The movable contact piece 16 is made of a conductive elastic material and is attached to a clutch member 15 so as to rotate integrally therewith, and the clutch member 15 is rotatably supported on the same axis of the drive gear 12. The drive gear 12 has a drive-side engaging portion 13 configured to rotate the clutch member 15 in the forward direction together with the drive gear 12 only when the drive gear 12 rotates in the forward direction. The drive gear 12 is disposed on the clutch member 15.
A driven side engaging part 18 is provided which engages with the driving side engaging part 13 so as to transmit the driving force of the driving gear 12 to the clutch member 15 only when the gear rotates in the forward direction. do.

[Effect]

According to the above means, under normal conditions, the clutch member rotates the conductive plate and the movable contact piece relative to each other as the drive gear rotates. On the other hand, when an external force is applied to the drive gear to cause it to rotate in the opposite direction, the clutch member does not follow the reverse rotation of the drive gear, thereby preventing the relative backward movement of the conductive plate and the movable contact piece. blocked. When the clutch member receives an urging force from the drive gear, the movable contact piece is separate from the clutch member, so that it maintains proper sliding contact with the conductive plate.

〔Example〕

Fig. 1 is a longitudinal sectional view showing a wiper drive device which is an embodiment of the present invention, Fig. 2 is a plan view taken along the line shown in Fig. 1 with the housing opened, and Fig. 3 is the same as Fig. 1. The bottom view taken along the - line and FIG. 4 are schematic diagrams for explaining the operation.

In this embodiment, the wiper drive device includes a housing 1, and the housing 1 forms a sealed chamber by fitting a lid 3 over an opening of a main body 2 forming a gearbox.
A crankshaft 4 is rotatably supported approximately at the center of the main body 2, and one end of a rod 7 is rotatably supported at the free end of the crank 5, which rotates integrally with the shaft 4, via a ball joint 6. The other end of the rod 7 is rotatably connected to the free end of the linkage 8. One end of the linkage 8 is fixed to a shaft 9 rotatably supported at a lower position in the window frame of the automobile.
A wiper arm 10 holding a wiper blade 11 at its free end is supported so as to rotate integrally with the wiper arm 10 .

A drive gear 12 integrally molded from hard synthetic resin is fitted to the end of the crankshaft 4 in the interior of the housing 1 so as to rotate together. A drive-side engaging portion 13 is provided in a protruding manner on a part of the end surface.

A support shaft 14 is fixedly suspended from the ceiling surface of the lid body 3 with its axis aligned with the crankshaft 4, and a clutch integrally formed with an insulating material such as hard synthetic resin is attached to the support shaft 14. The member 15 is fitted into the central shaft hole 15a, and is rotatably supported with its lower surface pressed by the flange 14a of the support shaft 14. A movable contact piece 16 is attached to the clutch member 15 so as to rotate together with the clutch member 15. The movable contact piece 16 is made of a plate material having conductivity and appropriate elasticity, such as brass, and has a planar shape as shown in FIG. It is stamped and formed into a roughly boat shape as shown. The movable contact piece 16 has a small hole 16b and a notch 16c for preventing rotation on the support shaft 14.
They are arranged around each other, and on the other hand,
The clutch member 15 also has protrusions 15b and 15c.
are arranged around the support shaft 14 and protrude from each other. By fitting these small holes 16b, notches 16c, and projections 15b, 15c, respectively, the movable contact piece 16 rotates integrally with the clutch member 15.

This movable contact piece 16 has a window hole 17 punched out in an appropriate shape on the outside of the shaft hole 15a, and is bent slightly in the thickness direction.
The window hole 17 and the warp cooperate with the elasticity of the movable contact piece 16 itself, so that a contact, which will be described later, is pressed against the conductive plate with an appropriate biasing force.

A driven side engaging portion 18 is provided on one side of the clutch member 15.
is protruded in a bent state so as to be pressed from above by a tongue piece 19 left uncut in the window hole 17, and the driven side engagement portion 18 is engaged only when the drive gear 12 rotates forward. Drive-side engaging portion 13 of gear 12
configured to engage.

The movable contact piece 16 has a pair of first contacts 20, 20 and a second contact 21 protruding from a wear-resistant chip made of a conductive material. 21 is a pair of first contacts 20, 2 so as to equalize the load on the support shaft 14 due to the elastic force of the movable contact piece 16 itself.
0 are arranged symmetrically to each other on the opposite side to the second contact 21.

That is, when each contact 20, 21 is pressed against a conductive plate (described later) by the elastic force of the movable contact piece 16, a load due to the reaction force acts between the movable contact piece 16 and the support shaft 14. . and the first and second
If the contacts are disposed unbalanced with respect to the support shaft, this load will act on the support shaft 14 in a biased manner, causing the problem that the support shaft will wear out in a short period of time. This was revealed by the inventor. Therefore, by preparing a plurality of first contacts 20 and disposing them symmetrically on the opposite side of the second contact 21, the load acting between the movable contact piece 16 and the support shaft 14 is uniformly applied to the support shaft 14. In this way, wear of the support shaft 14 is prevented.

On the ceiling surface of the lid body 3, an insulating substrate 23 made of an insulating material such as synthetic resin and formed into a substantially circular panel shape is arranged concentrically with the center line of the support shaft 14.
It is fixed by suitable means such as screwing with screws 22 or the like. A first conductive plate 24 and a second conductive plate 25 are arranged on the lower surface of the insulating substrate 23 so as to be concentric with the center line of the support shaft 14, and are fixed by suitable means such as implant molding. has been done.

The first conductive plate 24 arranged inside is formed in a circular shape, and the pair of first contacts 20 are always pressed into contact with the first conductive plate 24 by the elastic force of the movable contact piece 16 as described above. It's getting old. The second conductive plate 25 disposed on the outside is formed in a substantially C-shape, and the cutout portion substantially forms a non-conductive portion 26 . At the center of the non-conductive part 26, there is a stop position piece 2 formed in a substantially fan shape from a conductive plate material.
7 are arranged. The circular orbit drawn by the second conductive plate 25, the non-conductive part 26, and the stop position piece 27 includes:
The second contact 21 is always pressed against the movable contact piece 16 by the elastic force of the movable contact piece 16.

The first conductive plate 24, the second conductive plate 25, and the stop position piece 27 are connected as shown in FIG. 4 in an electric circuit consisting of a power source 29, a wiper switch 30, a motor 31, etc. Switch 2 opens and closes the electric circuit of the motor.
8.

A motor 31 is connected to one side of the housing 1, and a rotating shaft 32 of the motor 31 passes through the main body 2 and is inserted into the housing 1 so as to be perpendicular to the axial direction of the crankshaft 4. On the outer periphery of the insertion portion of the rotating shaft 32, there is a pair of worms (hereinafter sometimes referred to as a right-handed twist worm and a left-handed twist worm) 33, which are twisted in opposite directions.
34 are formed integrally with each other, and a pair of support shafts 35 and 36 are parallel to the crankshaft 4 at positions facing the worms 33 and 34 and on opposite sides of the rotating shaft 32. are protruding from each. Worm wheels 37 and 38 are fitted onto both support shafts 35 and 36 and are rotatably supported.
7 and 38 are meshed with the worms 33 and 34, respectively. Intermediate gears 39 and 40 are integrally connected to both worm wheels 37 and 38 with their axes aligned, and both intermediate gears 39 and 40
is meshed with the drive gear 12.

Next, the action will be explained.

(1) Wiping operation When wiper switch 30 is turned on, power supply 2
9. The ON contact of the wiper switch 30 is connected to the ground, so the motor 31 rotates.

The rotation of the motor 31 is transmitted from both worms 33 and 34 of the rotating shaft 32 to both worm wheels 37,
38 and intermediate gears 39, 40 to the drive gear 12. At this time, since the worm wheels 37 and 38 are engaged with the right-handed worm 33 and the left-handed worm 34 at positions opposite to each other with respect to the axis of the rotating shaft 32, a reaction force is exerted on the rotating shaft 32. This results in even action, resulting in effective power transmission and improved durability.

When the drive gear 12 rotates, this rotation is converted into reciprocating rotation of the wiper arm 10 by the crank 5, rod 7, linkage 8, and shaft 9 of the crankshaft 4, and this reciprocating rotation causes the wiper arm to rotate into the wiper blade 11. Perform the wiping operation.

During this wiping operation, the driving side engaging portion 13 and the driven side engaging portion 18 engage with each other, so the clutch member 15 rotates together with the driving gear 12.
The first and second contacts 20 and 21 of the movable contact piece 16, which are attached to rotate integrally with each other, revolve while slidingly contacting the first and second conductive plates 24 and 25. However, since the motor 31 is energized by bypassing the switch 28, the relative sliding of these contacts and the conductive plate does not affect the rotation of the motor 31.

(2) Normal fixed position stop operation When the wiper switch 30 is turned off, the ON contact in the wiper switch 30 is opened and the OFF contact is closed.

If the wiper switch 30 is randomly turned OFF and the wiper blade is located in the middle of the window when the wiper switch 30 is turned OFF, for example, as shown by the imaginary line in FIG. 4, the first and second contacts 2
0 and 21 are in contact with the first and second conductive plates 24 and 25, respectively. By this,
Power supply 29, motor 31, wiper switch 30
OFF contact, first conductive plate 24, first contact 20, movable contact piece 16, second contact 21, second conductive plate 25,
Since the motor 31 is electrically connected to the ground, the motor 31 continues to rotate.

As the motor 31 continues to rotate, the second contact 21
When the contact point 21 reaches the non-conductive portion 26 of the second conductive plate 25, the second contact 21 and the second conductive plate 25 are disconnected from each other, so that the motor 31 is no longer energized. Due to inertia in the rotation system such as the motor 31 and the drive gear 12, the second contact point 21 moves to the stop position part 27.
When you move to and touch this, the second contact 21,
Stop position piece 27, motor 31, wiper switch 30 OFF contact, first conductive plate 24, first contact 2
0, a closed circuit is formed between the movable contact piece 16 and the second contact 21, so the electric brake acts and the motor 3
1 will be stopped suddenly.

When the motor 31 is suddenly stopped in this way,
Since the correlation between each component is set so that the wiper blade 11 is in a fixed position at the lower corner of the window, the wiper switch 30 is turned OFF at random.
Even if the wiper blade 11 is moved, the wiper blade 11 is always stopped at a fixed position.

(3) Stopping operation in case of abnormality For example, as shown in Fig. 4, the wiper blade 11
When a push-back force is applied to the wiper arm 10, rod 7, etc., an external force F as shown by the broken line arrow acts on the crankshaft 4 via the crank 5, as shown by the solid line arrow. A rotational force P in the opposite direction to the normal rotational direction R is applied.

If the conductive plate 25 or the contact point 21 is configured to always rotate integrally with the drive gear 12 as in the conventional example, the contact point 21 has moved relatively to the non-conductive portion 26 as the drive gear 12 rotates forward. Since the drive gear 12 is reversely rotated by the reverse rotational force P applied to the crankshaft 4, it is relatively returned to its original direction and comes into contact with the conductive plate 25 again.
Due to this re-contact, the motor 31 is re-energized and rotated again, and the drive gear 12 is rotated in the forward direction R.
The contact 21 will be moved back to the non-conductive part 26. When the contact point 21 moves again to the non-conductive part 26, the reverse rotational force P is applied to the crankshaft 4 again, so that the contact point 21 is pushed back to the conductive plate 25. Thereafter, by repeating this operation, a chattering phenomenon occurs in which conduction and non-conduction are repeated between the contacts and the conductive plate.

However, in this embodiment, since the clutch member 15 is interposed between the drive gear 12 and the second contact point 21, such a chattering phenomenon is prevented.

That is, as shown in FIG. 4, the wiper blade 11 is moved to the lower side of the window and the snow 41 is removed.
When the second contact 21 moves on the second conductive plate 25 and reaches the non-conductive part 26 when receiving a push back force, the gap between the second contact 21 and the second conductive plate 25 is electrically opened. Therefore, the motor 31 is no longer energized. At this time, a reverse rotational force P is applied to the crankshaft 4.
When actuated, the drive gear 12 is rotated in the opposite direction because it is integrated with the shaft 4. However, since the drive-side engagement portion 13 and the driven-side engagement portion 18 are configured to disengage when the drive gear 12 rotates in the reverse direction, even if the drive gear 12 rotates in the reverse direction, Clutch member 15 will not rotate in reverse. In other words, only the drive gear 12 rotates in the reverse direction and the clutch member 15 is left behind.
The contact 21 will maintain contact with the non-conductive part 26. As a result, the motor 31 is maintained in a non-energized state, so the motor 31 continues to stop, and the wiper blade 11 continues to be stopped at the lower corner of the window.

According to this embodiment, the clutch member is interposed between the drive gear and the switch, and the movable contact piece is attached to the clutch member so as to rotate integrally with the clutch member, so that the drive gear may be damaged due to accumulation of snow or the like. It is possible to prevent the chattering phenomenon that may occur when a force in the opposite direction to the normal one is applied, and as a result, it prevents deterioration due to the heat generated between the conductive plate and the contact due to the chattering phenomenon. It is possible to improve durability.

Since the movable contact piece is attached to the clutch member so as to rotate integrally with the clutch member, it is possible to prevent the biasing force of the drive gear against the clutch member from being transmitted to the contact of the movable contact piece, and as a result, the contact becomes conductive. It is possible to always make sliding contact with the plate in an appropriate state.

By preparing multiple first contacts and symmetrically arranging them on the opposite side of the second contact, the load acting between the clutch member and the support shaft can be applied uniformly to the support shaft. can prevent wear.

Since the conductive plate is fixedly disposed on the housing side, the structure of the clutch member and movable contact piece can be simplified and miniaturized, and the grounding to the body does not go through the bearing of the drive gear. can be obtained directly and create a reliable grounding condition.

By implanting and molding the conductive plate into the insulating substrate, the number of parts, the number of assembly steps, etc. can be reduced.

Since the clutch member is separated from the drive gear, it is possible to avoid the risk of the clutch member rotating together due to grease or the like adhering to the drive gear when the drive gear rotates in reverse.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and may be modified without departing from the gist thereof.
It goes without saying that various changes are possible.

For example, the contact is not limited to being provided by fixing a chip to a movable contact piece and protrudingly provided, but may also be constructed by having a part of the movable contact piece protrude or not protruding and slidingly contacting the conductive plate as it is.

The drive gear may be configured to be directly driven by the worm.

[Effect of idea]

As explained above, according to the present invention, a clutch member is provided that rotates in one direction with respect to the drive gear, and movable contact pieces are respectively arranged on this clutch member so as to rotate relative to the conductive plate. Because of this configuration, it is possible to prevent the relative backward movement of the conductive member and the movable contact piece when a reverse rotational force acts on the drive gear.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing a wiper drive device which is an embodiment of the present invention, Fig. 2 is a plan view taken along the line shown in Fig. 1 with the housing opened, and Fig. 3 is the same as Fig. 1. The bottom view taken along the - line and FIG. 4 are schematic diagrams for explaining the operation. 1... Housing, 2... Main body, 3... Lid body,
4...Crankshaft, 5...Crank, 6...
... Ball joint, 7 ... Rod, 8 ... Linkage, 9 ... Shaft, 10 ... Wiper arm, 11 ... Wiper blade, 12 ... Drive gear, 13 ... Drive side engagement part, 14 ... Support axis, 14
a... Flange portion, 15... Clutch member, 15a...
Shaft hole, 15b, 15c...Protrusion, 16...Movable contact piece, 16b...Small hole, 16c...Notch, 17
... Window hole, 18 ... Driven side engaging portion, 19 ... Tongue piece, 20 ... First contact, 21 ... Second contact, 22
... Screw, 23 ... Insulating substrate, 24 ... First conductive plate, 25 ... Second conductive plate, 26 ... Non-conductive part, 2
7...Stop position piece, 28...Switch, 29...
...power supply, 30 ... wiper switch, 31 ... motor, 32 ... rotating shaft, 33, 34 ... worm,
35, 36... Support shaft, 37, 38... Worm wheel, 39, 40... Intermediate gear, 41... Snow.

Claims (1)

[Claims for Utility Model Registration] (1) A fixed position stopping device is provided that stops the wiper arm 10 at a predetermined position even when the wiper switch 30 is opened at random. The drive gear 12 is interposed between the housing 1 and the drive gear 12 driven by the motor 31 for driving the housing 1, and is disposed on the housing 1 side. By sliding the circular annular conductive plate 25 and the circular annular track of the conductive plate 25 and the non-conductive portion 26 as the drive gear 12 rotates, the motor 31 and a movable contact piece 16 constituting a switch 28 that opens and closes an electric circuit, and when the wiper switch 30 is opened at random, the conductive plate 25 and the movable contact piece 16 move to the predetermined position. The switch 28 is closed, and the movable contact piece 1 is in the predetermined position.
6 comes into contact with the non-conductive part 26,
In the wiper drive device in which the switch 28 is opened, the movable contact piece 16 is made of a conductive elastic material and is attached to the clutch member 15 so as to rotate integrally with the clutch member 15. is rotatably supported on the same axis of the drive gear 12, and the clutch member 1 is attached to the drive gear 12 only when the drive gear 12 rotates in the forward direction.
A drive-side engaging portion 13 configured to rotate the drive gear 12 together with the drive gear 12 in the forward direction is disposed on the clutch member 15.
Drive gear 1 rotates only when gear 2 rotates in the positive direction.
1. A wiper drive device characterized in that a driven side engaging portion 18 is provided which engages with the driving side engaging portion 13 so as to transmit a driving force of 2 to a clutch member 15. (2) The movable contact piece 16 has contacts 21, The wiper drive device according to claim 1, characterized in that a plurality of wiper drive devices 20, 20 are provided. (3) The wiper drive device according to claim 1, wherein the clutch member 15 is rotatably supported by the housing 1. (4) The wiper drive device according to claim 1, wherein the conductive plate 25 is disposed on the housing 1 concentrically with an extension line of the center of rotation.