JPH0348865Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Purpose of invention] <Industrial application field> The present invention relates to a sliding contact structure.

<Prior art> As a method for electrically connecting a rotating body, an electrode plate made of a good conductor is provided around the circumference of the rotating body made of an insulating material, and the electrode plate is made of a good conductor. A sliding contact structure is known in which a contact made of a conductive spring material such as a bronze material is brought into sliding contact.

As a device using such sliding contacts, for example, an automatic stop device incorporated in a wiper motor device for a vehicle is known. This device is installed integrally with the crankshaft that drives the wiper arm back and forth through a link mechanism, and an electrode plate covering an appropriate rotational angle range is attached to the axial end face of a reduction gear that is rotated by a DC motor. A pair of contacts fixed on the casing side is brought into sliding contact with this electrode plate, and the current between these contacts is interrupted in accordance with the rotation angle of the reduction gear, so that the current is set at the specified position. This is to stop the wiper arm.

A pair of contacts in such a sliding contact is
They are arranged adjacent to each other along a radial direction centered on the rotation axis of the reduction gear. At the same time, the surfaces on which the contacts including the electrode plates on the reduction gear slide are made to be the same plane in consideration of smooth sliding contact of the contacts. Therefore, if the attachment of the contactor becomes loose or the electrode plate becomes eccentric, there is a risk of abnormal contact between the contactor and the electrode plate.

<Problem to be solved by the invention> In order to prevent such inconvenience from occurring, relatively high manufacturing precision is required, or a large clearance that allows for errors is required between both contacts. Therefore, it is inevitable that the manufacturing cost will rise or the external dimensions will increase.

The present invention was developed to improve these inconveniences, and its main purpose is to provide an improved sliding contact structure that prevents abnormal contact between the contact and the electrode plate. It is about providing.

<Means for Solving the Problems> According to the present invention, this purpose is to provide two raceway surfaces that are arranged side by side on an insulator and have an electrode plate attached to at least one of them. A sliding contact structure in which two contacts slide relative to each other, and the two raceway surfaces are arranged such that the other raceway surface is higher than the one raceway surface to which the electrode plate is attached. This is achieved by providing a sliding contact structure characterized in that the contacts are formed in different steps.

<Function> In this way, by making one raceway surface to which the electrode plate is attached higher than the other raceway surface, the surfaces on which each of the two contacts slide can be made to be different planes as necessary. can. Therefore, even if misalignment occurs, it is possible to prevent both contacts from simultaneously sliding into contact with the raceway surface on one side to which the electrode plate is attached.

<Embodiments> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows the installed state of a wiper motor device 1 to which the present invention is applied. This wiper motor device 1 drives, via a link mechanism, a wiper arm 3b to which a wiper blade 3a for wiping rainwater adhering to a windshield 2 of a vehicle is attached, and is connected to a dash board panel 4 in an engine room. is fixed to.

The wiper motor device 1 and the wiper arm 3b are connected through a clamp arm and a link mechanism (not shown), and the rotating force of the wiper motor device 1 gives the wiper arm 3b a reciprocating motion shown by arrow A. ing.

The wiper motor device 1, as shown in FIG.
The wiper arm 3b is driven by an output shaft 8, which is composed of a DC motor 5 and a reduction gear 6, and is integrally connected to a final stage gear 7 of the reduction gear 6, via the above-mentioned crank arm or the like.

As is well known, the wiper arm 3b continues to rotate to a position along the lower edge of the windshield 2 even if the switch is turned off in the middle of rotation. Wiper arm 3b in this specified position
The automatic stop is performed by the cooperation of electrode plates 11 and 12 (described later) attached to the end face of the gear 7 and a pair of contacts 13 and 14 attached to the cover 9 of the reduction gear 6.

FIG. 3 shows an example of an automatic stop circuit.

On the end face of the gear 7 made of an insulating material, there is a short electrode plate 11 that is partially divided at a predetermined angle on its circumference, and a short electrode plate 11 is provided on the inner circumferential side of the divided part of the short electrode plate 11. And battery 15
A negative electrode plate 12, which is connected to the negative electrode and is grounded, is attached to the negative electrode while being insulated from each other. Further, a portion adjacent to the outer periphery of the negative electrode plate 12 is an insulating surface 16 where the end surface of the gear 7 is exposed.
It is said that

On the other hand, the pair of contacts 13 and 14 are made of phosphor bronze or the like, and are arranged adjacent to each other in a radial direction centered on the rotation axis of the gear 7 while being electrically insulated from each other. It is adapted to be able to come into elastic sliding contact with the end face of the.

The wiper switch 17 for operating the wiper motor device 1 from inside the vehicle has two contacts 18 and 19.
have. These contacts 18 and 19 are such that when the switch knob 20 is pushed in, one OFF contact 18 closes and the other ON contact 19 opens.
In addition, when the switch knob 20 is pulled out, the off contact 18 opens and the on contact 1 opens, contrary to the above.
9 is closed.

One terminal of both contacts 18 and 19 is connected to the positive electrode of the DC motor 5, the other terminal of the on contact 19 is connected to the positive electrode of the battery 15, and the other terminal of the off contact 18 is connected to the negative electrode. Each is connected to an inner contact 13 that can slide into plate 12.

Furthermore, the outer contactor 14 is connected to the positive electrode of the battery 15, and the negative electrode of the DC motor 5 is connected to the negative electrode of the battery 15 and ground.

First, when the switch knob 20 is turned on, the on contact 19 side is closed, and a power supply circuit for the DC motor 5 is established regardless of the positional relationship between the electrode plates 11, 12 and the contacts 13, 14.

Next, while the wiper is operating, the switch knob 20 is
When turned off, the off contact 18 side is closed. In this state, in the area where both contacts 13 and 14 are in sliding contact with short electrode plate 11, both contacts 1
Since a power supply circuit for the DC motor 5 is formed through the short electrode plate 11 and the short electrode plate 11, the DC motor 5 continues to rotate. Then, at the part where the short electrode plate 11 is divided, the outer contact 14 is attached to the insulating surface 16 of the gear 7, and the inner contact 1
3 respectively contact the negative electrode plate 12,
At the same time as the power supply to the DC motor 5 is cut off, both poles of the DC motor 5 are short-circuited on the negative side, and the DC motor 5 suddenly stops due to electromagnetic braking.

Now, if the sliding surfaces of both contacts 13 and 14 are on the same plane, eccentricity may have occurred between negative electrode plate 12 and both contacts 13 and 14 due to manufacturing errors, for example. , due to the sum deviation in the radial direction between both contacts 13, 14 and negative electrode plate 12, both contacts 13, 14 with respect to negative electrode plate 12,
14 may come into contact at the same time.

Therefore, in this invention, as shown in Figure 4,
The insulating surface 16 on the outer peripheral side of the negative electrode plate 12 is made to protrude, and a step indicated by dimension S is provided between the sliding surfaces of both the contacts 13 and 14.

By doing this, both contacts 13, 1
4 and the negative electrode plate 12 are somewhat eccentric relative to each other, the outer contactor 14 can be prevented from contacting the negative electrode plate 12.

Note that the front and rear portions 16a of the insulating surface 16 in the circumferential direction
In order not to interfere with the smooth sliding contact of the outer contactor 14, the outer contactor 14 is slightly inclined so as to smoothly connect with the general surface.

FIG. 5 shows a second embodiment of the present invention,
Portions corresponding to those in the first embodiment described above are given the same reference numerals and detailed explanation thereof will be omitted.

In this embodiment, on the inner peripheral side of the end face of the gear 7, there is a negative electrode plate that is partially divided along the circumference at a predetermined angle and is grounded to the negative electrode of the battery 15. 12 and the short electrode plate 11 provided on the outer peripheral side including the divided portion of the negative electrode plate 12 are attached to each other while being insulated from each other. Further, a portion adjacent to the outer periphery of the negative electrode plate 12 is an insulating surface 16 where the end surface of the gear 7 is exposed.

On the other hand, the pair of contacts 13 and 14 are adapted to be able to come into resilient sliding contact with the end face of the gear 7, similarly to the first embodiment.

One terminal of the two contacts 18 and 19 of the wiper switch 17 are both connected to the negative electrode of the DC motor 5, the other terminal of the on contact 19 is grounded to the negative electrode of the battery 15, and the other terminal of the off contact 18 is connected to the negative electrode of the battery 15. The terminal is connected to an inner contactor 13 that can slide into negative electrode plate 12.

Furthermore, the outer contactor 14 can slide only on the outer peripheral side of the shot electrode plate 11 and is connected to the positive electrode of the battery 15, and the positive electrode of the DC motor 5 is connected to the positive electrode of the battery 15. .

In the case of the second embodiment, first, when the switch knob 20 is turned on, the on contact 19 side is closed;
Regardless of the positional relationship between the electrode plates 11, 12 and the contacts 13, 14, a power supply circuit for the DC motor 5 is established.

Next, while the wiper is operating, the switch knob 20 is
When turned off, the off contact 18 side is closed. In this state, in the area where only the inner contactor 13 makes sliding contact with the negative electrode plate 12, the off contact 18,
Since a power supply circuit is formed for the DC motor 5 via the inner contactor 13 and the negative electrode plate 12, the DC motor 5 continues to rotate. When the outer contact 14 and the inner contact 13 simultaneously contact the short electrode plate 11 at the part where the negative electrode plate 12 is divided, the power supply to the DC motor 5 is cut off, and at the same time, the Both poles are short-circuited on the positive side, and the DC motor 5 suddenly stops due to electromagnetic braking.

In the case of this embodiment as well, as shown in FIG. 6, the insulating surface 16 on the outer peripheral side of the negative electrode plate 12 is made to protrude, and a step shown by dimension S is formed between the sliding surfaces of both contacts 13 and 14. By providing the negative electrode 1
It is possible to avoid contact of the outer contactor 14 with the outer contactor 2.

[Effects of the invention] As described above, according to the invention, it is possible to effectively eliminate malfunctions caused by manufacturing errors such as deformation of the contactor, loosening of the rotating part, eccentricity of the electrode plate, etc. . Therefore, it becomes possible to relax the control accuracy, which is effective in reducing manufacturing costs. Furthermore, the distance between both contacts can be set smaller, which is effective in reducing the size of the device.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view of a vehicle equipped with a wiper motor device to which the present invention is applied, and FIG. 2 is an overall perspective view of the wiper motor device. FIG. 3 is a schematic circuit diagram based on the first embodiment, and FIG. 4 is a partially cutaway perspective view of essential parts of the first embodiment. FIG. 5 shows the third embodiment of the second embodiment.
It is a circuit diagram similar to the figure, and FIG. 6 is a perspective view similar to FIG. 4. DESCRIPTION OF SYMBOLS 1... Wiper motor device, 2... Windshield, 3a... Wiper blade, 3b... Wiper arm, 4... Dash board panel, 5... DC motor, 6... Speed reduction device, 7... Gear, 8... ...Output shaft, 9...Cover, 11...Short electrode plate,
12...Negative electrode plate, 13...Inner contactor,
14...Outer contact, 15...Battery, 16...
...Insulating surface, 17...Wiper switch, 18...Off contact, 19...On contact, 20...Switch knob.

Claims (1)

[Claims for Utility Model Registration] Sliding in which two contactors slide relative to two raceway surfaces that are arranged side by side on an insulator and have an electrode plate adhered to at least one of them. A sliding contact structure, characterized in that the two raceway surfaces are formed at different levels so that the other raceway surface is higher than the one raceway surface to which the electrode plate is attached. Dynamic contact structure.