JPH0115202Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a clutch for an electric telescoping antenna for an electric telescoping antenna installed in an automobile or the like.

[Technical background of the invention]

In recent years, with the development of car electronics, the number of parts such as control equipment installed in automobiles and the like has increased, and the mounting space for a clutch for an electric telescoping antenna has become narrower. For this reason, there is a strong demand from the automobile industry for this type of clutch to be smaller and thinner. The present applicant has previously proposed a unitized clutch for electric telescoping antennas in response to the above-mentioned needs.

1 and 2 are diagrams showing an example of a clutch for an electric telescopic antenna proposed by the applicant, in which FIG. 1 is a sectional view and FIG. 2 is a sectional view taken along the - line in FIG. 1. . Reference numeral 1 in Figures 1 and 2
2 is a driving clutch plate connected to the drive source side, and 2 is a driven clutch plate connected to the load side. These clutch plates 1 and 2 are made of synthetic resin such as DURACON. As shown in FIGS. 1 and 2, the driving clutch plate 1 is formed into a drum-shaped case having an engagement groove 1b on the inner peripheral surface 1a, and is rotatably fitted into the driven clutch plate 2 formed in the shape of a disk. It matches.
A drive gear 1c for power transmission is formed on the outer periphery of the active clutch plate 1 and meshes with a worm gear (not shown) connected to a motor serving as a drive source.

Furthermore, an output gear 2a for expanding and contracting the antenna element is formed on the outer periphery of the driven clutch plate 2. A clutch mechanism housing recess 2b is formed on the fitting side of the driven clutch plate 2, as shown in FIG. In this storage recess 2b, there is a main drive clutch plate 1.
A sliding member 3 made of resin that slides on the inner circumferential surface 1a and a holding member 4 made of resin that holds the engaging member 5 are housed at positions 180 degrees apart, and there is a space between these members 3 and 4. Coil springs 6 and 7 are compressed and loaded.
The sliding surface 3a of the sliding member 3 is formed to have approximately the same curvature as the inner circumferential surface 1a of the drive clutch plate 1, and is pressed against the inner circumferential surface 1a of the drive clutch plate 1 by the elastic force of the coil springs 6, 7. There is. A cylindrical engagement member 5 made of, for example, stainless steel is held at the tip of the holding member 4 so as to be able to move forward and backward in the radial direction of the clutch plate. It is pressed against 1a.

The driven clutch plate 2 housing such a clutch mechanism is rotatably fitted to the driving clutch plate 1 as described above, and is connected to the rotating shaft 8 which is pivotally supported by the frame (not shown) of the antenna drive mechanism. It is attached, and only the driven clutch plate 2 is rotatable.

Next, the operation of the clutch configured as described above will be explained. When the motor power is turned on, a worm gear (not shown) meshed with the drive gear 1c of the active clutch plate 1 rotates in a predetermined direction, causing the active clutch plate 1 to rotate together with the rotating shaft 8. The driving clutch plate 1 has an engagement member 5 engaged with the engagement groove 1b.
to rotate the driven clutch plate 2 in the same direction. As a result, the output gear 2a of the driven clutch plate 2 runs the drive cord for extending and retracting the antenna element, causing the antenna element to extend and contract. When the expansion and contraction operation of the antenna element is completed, a larger load is applied to the driven clutch plate 2 than during expansion and contraction, and the locking force (clutching force) between the driving clutch plate 1 and the driven clutch plate 2 becomes smaller than the above load, so that they are not engaged. Part 5
is removed from the engagement groove 1b. When the engaging member 5 is disengaged from the engaging groove 1b, the driven clutch plate 2 stops rotating, and only the driving clutch plate 1 rotates until the limit switch is activated.

As described above, the electric telescopic antenna clutch proposed by the present applicant is compact because the driving clutch plate 1 and the driven clutch plate 2 are fitted and integrated, and the clutch mechanism is housed in the dead space. It has the advantage of being thin and lightweight since everything other than the engaging member 5 and the coil springs 6 and 7 are made of synthetic resin.

[Problems with background technology]

However, the following problems remain unsolved with such resin clutches for antennas. That is,
When this type of resin clutch is used for a long period of time, the sliding member 3 will be damaged by the inner circumferential surface 1a of the active clutch plate 1.
Since the clutch slides while being pressed against the clutch, the inner circumferential surface 1a of the drive clutch plate 1 and the sliding surface 3a of the sliding member 3 wear out, resulting in a decrease in clutch force and inferior durability compared to metal clutches. There was a drawback.

[Purpose of invention]

The present invention has been made to eliminate the above-mentioned drawbacks, and its purpose is to provide a clutch for an electric telescopic antenna that is small, thin, lightweight, and has excellent durability.

[Summary of the idea]

In order to achieve the above object, the present invention is characterized in that the sliding surface of the sliding member is formed of a polyurethane rubber-like elastic body.

[Example of idea]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a cross-sectional plan view of a clutch for an electric telescoping antenna showing an embodiment of the present invention, in which the same parts as in FIGS. 1 and 2 are given the same reference numerals.
In the figure, reference numeral 30 denotes an elastic fitting 31 made of a polyurethane rubber-like elastic material such as urethane rubber at the tip end.
It is a sliding member made of resin with a The tip end surface of the elastic contact 31 of this sliding member 30 is formed with approximately the same curvature as the inner circumferential surface 1a of the active clutch plate 1. Therefore, the sliding surface 30a of the sliding member 30 is in elastic contact with the inner circumferential surface 1a of the driving clutch plate 1 due to the elastic force of the coil springs 6 and 7.

Next, the effect will be explained. Polyurethane rubber-like elastic bodies generally have a higher spring constant than metal springs, rubber cushions, etc., and have extremely low loss of weight. A sliding surface 30a, which is the tip end surface of the elastic contact 31, is elastically deformed according to the elastic force of the coil springs 6 and 7, and slides on the inner circumferential surface 1a of the active clutch plate 1. Therefore, the active clutch plate 1
and the sliding surface 30a of the sliding member 30.
Compared to the conventional case where resins are rubbed together, the amount of wear can be reduced and a decrease in clutch force can be prevented. Furthermore, since the elastic contact 31 has a high spring constant, the pressure force of the engagement member 5 against the engagement groove 1b is increased, and the coil springs 6 and 7 can be made smaller to obtain the required clutch force. It is possible.

In this way, in this embodiment, the sliding member 30
By providing an elastic contact 31 made of polyurethane rubber-like elastic material at the tip end of the clutch, the durability of the resin clutch can be improved.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and for example, the entire sliding member may be formed of a rubber-like elastic body. It goes without saying that the same effect can be obtained if the driven clutch plate 2 is a drum-shaped case and the main drive clutch plate 1 is a disk rotatably fitted within the case.

[Effect of idea]

As described above, according to the present invention, the sliding surface of the sliding member that slides on the inner circumferential surface of the drum-shaped case is made of polyurethane rubber-like elastic material, so it is small, thin, lightweight, and durable. It is possible to provide an excellent clutch for an electric telescopic antenna.

[Brief explanation of the drawing]

1 and 2 are diagrams showing an example of a conventional electric telescopic antenna clutch, in which FIG. 1 is a sectional view, FIG. 2 is a cross-sectional plan view taken along the - line in FIG. FIG. 2 is a cross-sectional plan view of a clutch for an electric telescoping antenna showing one embodiment. 1... Active clutch plate, 1b... Engagement groove, 2...
...Driver clutch plate, 3, 30...Sliding member, 5...
...Engaging member, 6, 7... Coil spring, 8... Rotating shaft, 31... Elastic fitting.

Claims (1)

[Scope of utility model registration request] One of the active clutch plate coupled to the motor side and the driven clutch plate coupled to the antenna element side is formed in a resin drum-shaped case having an engagement groove on the inner peripheral surface, and the other is housed in the drum-shaped case. Formed in a resin disc that can be rotatably fitted and has a clutch mechanism storage recess on the plate surface on the fitting side,
The clutch mechanism storage recess includes an engagement member that engages with the engagement groove, a sliding member that slides on the inner peripheral surface of the drum-shaped case, and an elastic member that is compressed and elastically mounted between these two members. What is claimed is: 1. A clutch for an electric telescoping antenna, wherein the sliding surface of the sliding member is formed of a polyurethane rubber-like elastic material.