JPS6233517Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a fixed position stopping device for an automobile motor drive device.

Generally, this type of fixed position stopping device is employed in a wiper motor drive device or a vertical motion motor drive device for a retractor head lamp. For example, in the case of a wiper motor drive device, as shown in Fig. On the insulating (synthetic resin) gear 2 to be driven, a first conductive plate 3 with a part of its outer periphery cut out, and a second conductive plate 4 inside the cutout are provided. The first
At the same time, the first brush 5 is connected to the off terminal of the wiper switch 7, while the second brush 6 is placed to face the rotation locus of the second conductive plate 4.
is connected to one end of the motor 1 connected to the power supply B, and when the wiper switch 7 is turned off, the first and second brushes 5 and 6 on the second conductive plate 4 short-circuit both ends of the wiper motor 1, and the wiper motor 1 It is designed to stop at a fixed position.
(see publication).

Specifically, as shown in FIGS. 2 and 3, the worm 10 of the armature shaft 9 of the wiper motor 1 housed in the motor case 8 is inserted into the insulating gear 2 in the gear case 12 covered with the gear case cover 11. The first conductive plate 3 on the gear 2 drives the output arm 15 which is linked to the wiper arm via the drive shaft 14 supported by the bearing 13. For the second conductive plate 4,
A first brush 5 and a second brush 6 are provided on a brush base 16 attached to a gear case cover 11, and a gear 2 is inserted through an arm tongue piece 17 formed around the inner periphery of the first conductive plate 3 to connect the gear. 2, and the grounding brush 18 was brought into contact with a grounding plate 19 on the gear case 12, which is grounded to the body.

Therefore, since it is necessary to use an insulating material as the gear 2, a grounding tongue piece 17 is separately formed on the first conductive plate 3, through which the gear 2 is inserted, and further connected to the grounding brush 18. Brush 18
It is necessary to adopt a grounding structure in which the grounding plate 19 is brought into contact with the grounding plate 19, which results in a problem that the structure becomes complicated and the number of assembly steps increases.

This invention was made in order to solve the above-mentioned conventional problems, and the first and second brushes form a conductive part and a non-conductive part on the outer circumferential surface of a conductive drive shaft driven by a motor. In addition to controlling the wiper motor to stop at a fixed position, the conductive drive shaft is brought into contact with the gear case, which is grounded to the body, via a bearing, etc., so that a special grounding device is not required. It is.

Hereinafter, embodiments of this invention will be described in detail with reference to the accompanying drawings.

Note that parts having the same structure and function as those of the above-mentioned conventional example are given the same numbers, and detailed explanations will be omitted.

As shown in FIGS. 4, 5, and 6, serrations 21 are attached to the insulating (synthetic resin) gear 2.
A conductive (metallic) drive shaft 22 supported by a bearing 13 connected to the gear case 12 is provided, and a part 24 of the outer periphery of the large diameter head 23 of the drive shaft 22 is cut off. Serrations 21 of the drive shaft 22 protruding from the upper surface of the gear 2
is covered with the boss portion 25 of the gear 2 having the same diameter as the outer diameter of the large diameter head 23, and
The cutout portion 24 of the boss portion 25 is attached to the extension piece portion 26 of the boss portion 25.
The drive shaft 22 is insert molded into the gear 2 so as to compensate for this.

A conductive plate 27 having a predetermined width and having the same diameter as the outer diameter of the large-diameter head 23 is insert-molded at the center of the outer peripheral surface of the extension piece 26 of the boss 25 over the entire length of the boss 25 .

Therefore, the large-diameter head portion 23 of the drive shaft 22 has a first conductive portion 28a formed by the large-diameter head portion 23 that occupies about 3/4 of the outer peripheral surface, and an insulating portion (non-conductive portion) of the extension piece portion 26 at the upper stage. A first track peripheral surface part 29 is formed by the second conductive part 28c of the conductive plate 27 via the conductive plates 28b and 28b, and the outer peripheral surface is approximately 3/3
A second track circumferential surface portion 30 is formed by an insulating portion 28d formed by the boss portion 25 that occupies 4, and a second conductive portion 28c formed by the conductive plate 27 via the insulating portions 28b, 28b of the extension piece portion 26. .

The first conductive portion 28a of the first track circumferential surface portion 29 is such that the drive shaft 22 itself is conductive.
The gear case 12, which is grounded to the body, comes into ground contact via the bearing 13.

On the other hand, an insulating brush base 31 is attached to the bulging cover portion 11a of the gear case cover 11, and a first brush 32 that is in sliding contact with the first track circumferential surface portion and a second track circumferential surface portion are attached to the brush base 31. A second brush 33 that is in sliding contact with is provided.

The first brush 32 is connected to the off terminal of the wiper switch 7 like the conventional first brush 5, and the second brush 33 is connected to one end of the wiper motor connected to the power source B, like the conventional second brush 6. Ru.

Therefore, if the fixed position stop device is configured as described above, when the wiper motor 1 starts driving when the wiper switch 7 is turned on, the gear 2 is decelerated and rotated by the rotation of the worm 10 by the armature shaft 9, and the The output arm 15 linked to the wiper arm is driven by the wiper.

When the wiper switch 7 is turned off while the wiper is being driven, the second brush 33 is located at the insulating section 28d of the second track circumferential section 30, but the first brush 33
is located in the first conductive part 28a of the first track circumferential part 29, so the body is grounded from the drive shaft 22 to the gear case 12 via the bearing 13, and the circuit of the power supply B of the wiper motor 1 is in a closed state. Therefore, the wiper motor 1 continues to drive.

The first brush 32 and the second brush are driven by the wiper motor 1.
Both the brush 33 and the first track circumferential portion 30
When the wiper motor 1 is located at the second conductive portion 28c of the second track circumferential surface portion 31, both ends of the wiper motor 1 are short-circuited, and the wiper motor 1 stops driving at a fixed position.

In the above embodiment, the first and second track circumferential parts 29 and 30 are formed on the large-diameter head 23 of the drive shaft 22, but the middle part of the drive shaft 22 and the lower end part near the wiper motor 15 are It is also possible to have a configuration in which it is formed as follows.

As is clear from the above description, this invention provides first and second track circumferential surface portions consisting of a conductive portion and a non-conductive portion on which the first and second brushes respectively slide on the outer circumferential surface of the conductive drive shaft. Since the drive shaft is grounded to the body through the gear case, there is no need to provide a separate grounding device as in the conventional case, which simplifies the structure and reduces the number of assembly steps. It becomes like this.

[Brief explanation of the drawing]

Fig. 1 is a wiper motor circuit diagram, Fig. 2 is a partial cross-sectional plan view of a fixed position stop device of a conventional wiper motor device, Fig. 3 is a sectional view taken along the - line in Fig. 2, and Fig. 4 is a wiper motor according to this invention. A partial cross-sectional plan view of the fixed position stopping device of the device, FIG. 5 is the same as in FIG.
The line sectional view and FIG. 6 are perspective views of essential parts of the gear and the drive shaft. 1... Wiper motor, 2... Gear, 13...
Bearing, 15... Wiper arm, 22... Drive shaft, 23... Large diameter head, 24... Resection part, 25
... Boss part, 26 ... Extension piece part, 27 ... Conductive plate, 28a ... First conductive part, 28b, 28d ...
Insulating part, 28c... Second conductive part, 29... First track circumferential part, 30... Second track circumferential part, 3
1... Brush base, 32... First brush, 33
...Second brush.

Claims (1)

[Scope of utility model registration request] First and second brushes for controlling the rotation and stopping of the motor are respectively disposed in sliding contact with first and second track peripheral surfaces formed on the outer peripheral surface of a conductive drive shaft driven by the motor. , a conductive plate of a predetermined width having a length spanning the first and second track circumferences is attached to the first and second track circumferences via an insulating material, and the second track circumference is connected to the conductive plate. A fixed position stop device for an automobile motor drive device, characterized in that the plate is covered with an insulating material.