JPS6364082B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a clutch for an electric telescoping antenna installed in an automobile or the like, and more particularly to an improvement in the engaging portion of a resin clutch plate.

The conventional engagement portion of this type of clutch plate has a steel ball with its tip end pressed against the pressure contact surface of either the active clutch plate connected to the drive source side such as a motor, or the driven clutch plate connected to the load side. The steel ball is embedded and fixed so as to be in sliding contact with the other pressure contact surface, and an engagement groove is provided on the circumference facing the steel ball on the other pressure contact surface, and the steel ball and the engagement groove are engaged with each other. The driving clutch plate and the driven clutch plate are configured to rotate together. As a result, after the expansion and contraction of the antenna element, which is the load, is completed and the drive cord of the antenna element stops running, the clutch plate repeats engagement and disengagement until the motor is stopped by the operation of the limit switch. As a result, the steel balls apply a severe impact to the upper edge of the engagement groove, causing significant wear on the upper edge, shortening the life of the clutch plate, and making it impossible to withstand long-term use.

In recent years, in the automobile industry, there has been a strong demand for clutch plates of this type to be smaller, lighter, and lower in cost for use in energy-saving vehicles.

The present invention has been developed in view of the above circumstances, and is small, thin, lightweight, has excellent abrasion resistance, can be used stably over a long period of time, and can be produced at an extremely low cost. The purpose is to provide a clutch for an antenna.

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings.

FIGS. 1A and 1B are diagrams showing the shape of a driving clutch plate according to an embodiment of the present invention. In the same figure,
This active clutch plate 1 has a disk shape,
It is made of hard synthetic resin material. A rectangular shaft hole 1a is provided in the center of the active clutch plate 1.
is provided, and this shaft hole 1a is bored so as to be non-rotatably fitted to a rotating shaft which will be described later.
A recessed portion 1b for storing an elastic plate, which will be described later, is formed on one side of the active clutch plate 1, as shown in the shaded area in FIG. A through hole 1c is provided in this storage recess 1b, and this through hole 1c is bored so that a part of the outer peripheral surface of a steel ball, which will be described later, protrudes and can freely move within the through hole 1c. has been done. Further, in the same figure, the reference numeral 10 is a driving force transmission gear disposed around the outer circumferential surface of the active crank plate 1, and this driving force transmission gear 10 is connected to a motor (not shown) as a driving source. There is.

Next, FIGS. 2A and 2B show the shape of a driven clutch plate which is an embodiment of the present invention. As shown in the figure, the driven clutch plate 2 is made of a synthetic resin material and has a disk shape, similar to the above-mentioned active clutch plate 1. A stepped shaft hole 2a having a small diameter hole in the upper stage and a large diameter hole in the rear stage is provided in the center of the driven clutch plate 2, and the stepped shaft hole 2a is fitted with a rotation shaft to be described later. , is drilled so that it can rotate freely. Further, on one side surface of the driven clutch plate 2, that is, on the side surface 2d facing the driving clutch plate 1, a circumferential groove 2b is formed over the entire circumference on the circumference corresponding to the through hole 1c of the driving clutch plate 1. It is formed as follows. That is, the circumferential groove 2b is formed on a track on which a part of the outer peripheral surface of the steel ball slidably moves in the through hole 1c as described above. Also, this circumferential groove 2
A rectangular roller housing groove 2c, which is slightly longer in the radial direction than the groove width, is provided in a part of b. This roller housing groove 2c has a cylindrical roller which will be described later.
The circumferential groove 2b is formed one step deeper than the circumferential groove 2b so as to protrude from the bottom surface of the groove. In the same figure, the reference numeral 20 is an output gear disposed around the outer peripheral surface of the driven clutch plate 2, and this output gear 20 meshes with a drive cord (not shown) of the antenna element.

FIGS. 3A and 3B illustrate the structure of a clutch mechanism which is an embodiment of the present invention and is comprised of the above-mentioned clutch plates 1, 2, etc. In the figure, the reference numeral 3 indicates a rotation shaft that is fitted into the shaft holes 1a, 2a of the clutch plates 1, 2, as described above. The rotating shaft 3 is rotatably provided between frames (not shown) of the antenna drive mechanism, and a rectangular circular shaft portion is provided with a threaded portion 3a. This rotary shaft 3 has a multistage shape, and the large diameter portion 3b of the rotary shaft 3 serves as a stopper to prevent the driven clutch plate 2 from slipping out.

Next, reference numeral 5 designates an elastic plate that is housed in the elastic plate housing recess 1b of the active clutch plate 1. This elastic plate 5 is a through hole 1c of the active clutch plate 1.
It applies a predetermined pressing force to the steel ball 4 that is slidably moving therein, and is fixed by a nut 6 screwed into the threaded portion 3a of the rotating shaft 3. The above pressing force is adjusted depending on the degree of tightening.

On the other hand, as described above, the steel ball 4 is inserted into the through hole 1c in a loosely fitted state, and a part of its outer peripheral surface is constantly aligned with the circumferential groove 2b of the driven clutch plate 2 due to the pressing force of the elastic plate 5. It is in sliding contact with the bottom surface with a constant contact pressure.

In addition, as described above, the one indicated by the reference numeral 7 has a part of its outer peripheral surface in the roller housing groove 2c provided in a part of the circumferential groove 2b as the sliding contact surface of the steel ball 4 (in this embodiment, the circumferential groove It is a cylindrical roller that protrudes from the bottom surface of 2b and is detachably attached. That is, this roller 7 constitutes an engaging convex portion with respect to the steel ball 4.

Next, the operation of the embodiment of the present invention constructed as described above will be explained with reference to FIGS. 4A and 4B.

FIGS. 4A and 4B are views showing engagement and disengagement between the steel ball 4 and the roller 7 serving as the engagement convex portion. First, when the motor power source (not shown) is turned on, the driving force of the motor is transferred to the driving force transmission gear 10.
The driving clutch plate 1 rotates together with the rotating shaft 3. The rotational force of the driving clutch plate 1 is transmitted to the driven clutch plate 2 via the steel balls 4 in the engaged state shown in FIG. 4A. Therefore, the driven clutch plate 2
rotates together with the active clutch plate 1, and causes the drive cord of the antenna element to travel with a predetermined clutch force (locking force in the direction of rotation).

When the expansion and contraction of the antenna element is completed, the drive cord stops running, so that a load greater than a predetermined clutch force (locking force) is applied to the driven clutch plate 2. As a result, the steel ball 4 moves upward and overcomes the roller 7, reaching the detached state shown in FIG. Slides stably under pressure. Thereafter, the steel ball 4 repeats the engagement and disengagement described above until the motor power is turned off, and idles on the circumferential groove 2b.
As a result, the steel ball 4 moves upward to reduce the impact force on the clutch plate engaging portion after the antenna element has completed its expansion and contraction operation, and the wear of the roller 7, which serves as the engaging convex portion, is significantly reduced. ing.

Further, in this embodiment, the roller 7 has a circumferential groove 2c.
Since the rollers are detachably attached to the rollers, it is possible to replace the rollers due to wear, etc. Furthermore, since the elastic plate 5 is in the form of a flat plate, a nearly constant contact pressure can be applied to the steel ball 4 by appropriately tightening the nut 6. This prevents the antenna element from falling due to its own weight.

In this embodiment, a multistage rotary shaft 3 is used to prevent the driven clutch plate 2 from slipping out, but depending on the purpose of use, it may be possible to use a shaft that is not stepped but is connected to the drive force transmitting gear, for example. The cylindrical portion may hold the driven clutch plate rotatably, or a metal cap may be used as the fixing fitting instead of the nut 6, and a predetermined contact pressure depending on the model used during assembly may be obtained by caulking. good. Furthermore, by arranging a plurality of steel balls 4 on the same side and correspondingly providing an engaging convex portion on the other clutch plate, a large locking force that enables normal starting even in the case of freezing can be achieved. Needless to say, you can get it.

It should be noted that the present invention is not limited to the embodiments described above, and it goes without saying that various modifications can be made without departing from the spirit of the invention.

As explained above, the present invention provides the following effects.

(a) Since cylindrical bodies such as steel balls and rollers are used in the engaging portions of the resin clutch plate, wear caused by impact when the housing grooves of the cylindrical bodies are engaged and disengaged can be minimized. Furthermore, since the steel balls are designed to slide while being guided by the circumferential groove, the movement is stable even when the clutch is disengaged and spins idly.

(b) Since a cylindrical body is used for one of the above-mentioned engaging parts and the groove of the steel ball sliding raceway (circumferential groove 2b) is formed to be almost the same length as the length of the cylindrical body, it is easy to form the sliding raceway. Accuracy is not required and it can be put to practical use even if there is some deviation. As a result, product standards management becomes easier and costs are reduced.

(c) Components other than the cylindrical body, steel balls, and elastic plates can be made of resin, reducing weight and cost.

(d) Since a flat elastic plate is used instead of a bending elastic plate, not only can a nearly constant contact pressure be obtained by tightening the tightening nut, but it can also be used for ``caulking'' work, which is suitable for the model used. The contact pressure can be easily adjusted.

[Brief explanation of drawings]

1 to 4 are diagrams explaining one embodiment of the present invention, in which FIG. 1A is a plan view of the active clutch plate, FIG. 1B is a sectional view taken along the line A--A in FIG. FIG. 2A is a plan view of the driven clutch plate, FIG. 2B is a sectional view taken along the line B-B in FIG. 4A and 4B are explanatory diagrams illustrating the state of engagement and disengagement between the steel ball and the roller. 1... Drive clutch plate, 2... Driven clutch plate, 3... Rotating shaft, 4... Steel ball, 5...
...Elastic plate, 7...Roller, 10...Driving force transmission gear, 20...Output gear.

Claims (1)

[Claims] 1. A resin active clutch plate coupled to the motor side, a resin driven clutch plate coupled to the antenna element side, and a radially long rectangular groove provided in one of the active clutch plate or the driven clutch plate, A cylindrical body accommodated in the rectangular groove and arranged so that a part of its outer peripheral surface protrudes from the plate surface;
A circumferential groove that communicates with the rectangular groove and is formed shallower than the rectangular groove, a steel ball that slides within the inner circumferential groove with a part of its outer circumferential surface invaginated, and The clutch plate is characterized by comprising an engagement hole formed in the other clutch plate so that the other part is recessed, and an elastic plate that applies a predetermined contact pressure to the steel ball through the engagement hole. Clutch for electric telescopic antenna.