JPS596148A - Clutch for motor telescoping antenna - Google Patents

Abstract

PURPOSE:To prevent intrusion of rain water or dust by fitting main clutch board and inverted clutch board rotatably then coupling through a pin such that upon application of heavy load on the inverted clutch, the pin is disengaged to block both clutch boards. CONSTITUTION:An inverted clutch 12 of drum case and main clutch board 11 of disc shape are fitted rotatably. Pressure members 17A, 17B are placed in the recess 11c of the clutch board 11 and energized radially by means of coil springs 18A, 18B. It is arranged such that the pin 16 is engaged in the engaging groove 12e of the clutch board 12 by means of the pressure member 17A. Consequently upon rotation of main clutch board 11 by means of motor, the rotation is transmitted through the inverted clutch board 12 to the rotary shaft 13 thus to telescope the antenna. Upon completion of antenna, heavy load is applied on the inverted clutch board 12 to remove the pin 16 from the groove 12e thus to rotate only the main clutch board 11.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a clutch for an electric telescopic antenna installed in, for example, an automobile, and more particularly to an improvement in a latch suitable for a drive mechanism of a small and thin electric telescopic antenna.

As is well known, this type of conventional clutch expands and contracts the antenna element, which is the load, by pressing one side of the driving clutch plate connected to the motor side to one side of the driven clutch plate connected to the load side. At the same time, when the expansion and contraction of the antenna element is completed, the structure is such that only the motor is rotated until the motor power is turned off by the action of the limit switch due to the sliding of both clutch plates, thereby preventing the motor from locking. It had been.

FIGS. 1 and 2 are diagrams showing a conventional example configured as described above. In the figure, when a worm wheel 2 meshing with a worm gear 1 connected to a motor shaft (not shown) rotates due to the driving force of the motor, a pipe-shaped rotating shaft 4 rotatably fitted into a fixed shaft 3 rotates. Accompanying this, the metal active clutch plate 6, which is fitted and fixed to the rotating shaft 4 and to which a pressing force is applied by the bending elastic plate 5, rotates. When this driving clutch plate 6 rotates, the driven clutch plate 7, which is in pressure contact with the driving clutch plate 6 and rotatably fitted to the rotating shaft 4, rotates. Drive cord 9 meshing with gear 8
is transported in the longitudinal direction. Therefore, the antenna element (not shown) connected to this drive cord 9 expands and contracts.

By the way, as shown in the figure, the driving clutch &6 has engagement recesses 6h+6b on the pressure contact surface facing the driven clutch plate 7.
6c are formed on the same circle at equal intervals. Further, on the pressure contact surface of the driven clutch plate 7 facing this, the engagement recess 6a is provided.

Steel ball 7 serves as an engaging convex portion that engages with 6b and 6C.
a+7b and 7c are buried on the same circumference with a part thereof protruding from the pressure contact surface.

Therefore, when the drive cord 9 is transferred, the engagement recess 6&I e b *6C of the driving clutch plate 6 is connected to the steel sole 7h of the driven clutch plate 7.

7 b * 7 e, the driven clutch plate 7 can obtain a predetermined locking force in the direction of rotation, that is, a clutch force, and the rotation of the driven clutch plate 7 is stopped when the antenna element completes expansion and contraction. Accordingly, the engagement between the active clutch plate 6 and the driven clutch plate 7 is released, so that only the active clutch plate 6 rotates, thereby preventing the motor (not shown) from locking.

However, in the conventional clutch mechanism configured as described above, when slip occurs between the driving clutch plate and the driven clutch plate, for example, when the antenna element is extended or when the contraction is completed, the opposing surfaces of each clutch plate are The provided engaging portions, that is, the engaging recesses 6a to 6C and the steel balls 7a to
7C repeatedly engages and disengages, which has the drawback of generating a large amount of noise and causing considerable wear on the uneven portions of the engagement portion, resulting in a short life span. Particularly in cold regions, in order to allow the antenna element to extend and retract normally even if it freezes, slippage between the clutch plates is difficult to occur, resulting in a large latching force, resulting in severe wear.

In addition, in the past, the active clutch plate, steel goal, etc. were made of metal, which had the disadvantage that if rainwater or dust entered the mechanism, "rust" would occur, resulting in failures such as inability to start. Furthermore, due to large variations in clutch force when assembling the clutch, an excessive latching force is applied to the drive cord, etc. As a result, when the antenna element is fully extended or retracted, the drive cord is extremely bent and easily damaged. there were.

Therefore, the present invention was devised to eliminate the above-mentioned drawbacks of the conventional technology, and has a structure that does not cause failures such as inability to start even if rainwater or dust enters, has a simple structure, and is easy to assemble. The purpose of this invention is to provide a clutch for an electric telescoping antenna that has excellent wear resistance.

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

3(A) and 3(B) are diagrams showing the structure of the driving clutch plate 11 of the clutch mechanism which is an embodiment of the present invention, and FIG. It is a figure showing a structure.

As shown in FIGS. 3(A) and 3(B), the main drive clutch plate 11 has a rotating shaft 13 (see FIG. 5) rotatably provided between the frames (not shown) of the antenna drive mechanism in its center. A shaft cylinder 11b having a rotation hole 11a into which the shaft cylinder 11b is rotatably fitted is provided. This shaft cylinder 11b has a rectangular shape and protrudes one step lower than the side surface of the clutch plate 11, and a rectangular circular recess 11c is formed around the shaft cylinder 11b.

In addition, 180° of the peripheral wall lid of this active clutch plate 110
At different positions, there is a middle notch lie and a wide notch 11.
f are provided facing each other, and four rectangular circular parts 11c are provided.
Together with this, a recess for assembling and accommodating clutch components, which will be described later, is formed.

The active clutch plate 11 is made of a synthetic resin material such as Shuracon (trade name), and a drive gear 14 for transmitting driving force of a motor or the like is disposed around its outermost periphery. Further, the outer circumferential surface 11g of the circumferential wall JJd is formed to rotatably fit into the inner circumferential surface of the circumferential wall of a driven clutch plate 12, which will be described later.

On the other hand, the driven clutch plate 12 has a drum-shaped case as shown in FIGS. A shaft cylinder 1 having a fitting hole 121L that is fitted and fixed to the shaft 13
2b is provided.

Also, one side of this driven clutch plate has four circular parts 12.
c. A circular arc-shaped engagement groove 12e is formed on the inner peripheral surface 12g of the peripheral wall 12d. Furthermore, an output gear 15 that meshes with a drive cord (not shown) of the antenna element is provided around the outer peripheral surface of the peripheral wall 12d of the driven clutch plate 120. peripheral wall 12rl of driven clutch plate 12 with
The outer circumferential surface 1 of the active clutch plate 11 is on the inner circumferential surface 12g of the main drive clutch plate 11.
1g is fitted rotatably. In addition, the active clutch plate 11
A clutch component, which will be described later, is incorporated into the recess 12e.

FIGS. 5 and 6 are diagrams showing a state in which a driving clutch plate 11 and a driven clutch plate 12 are combined with a clutch structure inside them.

In Figures 5 and 6, reference numeral 16 is a cylindrical bottle as an engaging member, 171L and 17B are pressure members, and 18A and 18B are coils. The pin 16 is provided in a notch lie in the middle of the driving clutch plate 11 so as to be able to move forward and backward in the radial direction. The parts are formed so that they engage.

Further, a pressure member 17k is fitted and housed inside the notch 11e of the middle sandwich, and the tip of the protrusion is in contact with the outer circumferential surface of the bottle 16.

On the other hand, a pressure member 17B is fitted and housed on the wide notch 11f side. The tip of the protruding portion of the pressure member 27B forms an arc-shaped curved surface having approximately the same curvature as the inner circumferential surface 12g of the driven clutch plate 12, and is in sliding contact with the inner circumferential surface 12g.

Note that, like the main drive clutch plate 11, the pressure member 17 is made of a synthetic resin material. Also,
A coil spring 1B is connected between these pressure members 17 and 17B.
k, 18B is compressed, and the pressurizing member 17 is loaded with 1
7B is always biased outward.

Therefore, the tips of the protrusions of the bottle 16 and the pressure member 17B are always in pressure contact with the inner circumferential surface 12g of the driven clutch plate 12.

Next, the operation of this embodiment having the above structure will be explained.

When the motor power is turned on, the gear connected to the motor shaft (
Drive gear 1 (not shown) rotates and meshes with this gear.
4 rotates the main drive clutch plate 11. The driving clutch plate 11 connects the driven clutch plate 12 to the rotating shaft 13 via the pin 16 that is engaged with the engagement groove 12e of the driven clutch plate 12.
and rotate in the same direction. Therefore, the drive cord (not shown) of the antenna element is connected to the driven clutch plate 12.
It is driven by an output gear 15 disposed around the antenna element to extend or contract the antenna element. When the antenna element is expanded or contracted in this way, a greater load is normally placed on the driven clutch plate 12. As a result, the locking force (clutch force) between the driven clutch plate 12 and the main drive clutch plate 11 becomes smaller than the load.
is disengaged from the engagement groove 12e, the driven clutch plate 12 stops rotating, and only the driving clutch plate 1 rotates. FIG. 7 shows the change in the locking force at this time.

FIG. 7 shows the change in the locking force during one rotation of the driving clutch plate 1 within the driven clutch plate 12. In the figure, point a is the maximum locking force of the main drive clutch plate 11;
This corresponds to a state in which the bottle 16 is engaged with the engagement groove 12o. Further, b is an average locking force, which mainly corresponds to the frictional force generated when the tip end surface of the protrusion of the pressure member J7B slides in pressure contact with the inner circumferential surface 12g of the driven clutch plate 12.

Therefore, as is clear from the figure, by appropriately setting the depth of the engagement groove 12e of the driven clutch plate 12, the pin 16 can be moved into the engagement groove 12e when the antenna element is expanded or contracted.
2e, only the active clutch plate 11 rotates, and locking of the motor can be prevented. Further, by appropriately setting the elastic force of the coil spring 180, it is possible to prevent the antenna element from falling due to its own weight.

In this embodiment, the driven clutch plate side is formed into a drum-shaped case, but the driving clutch plate side may be formed into a drum-shaped case.

As is clear from the above description, according to the present invention, since the driving clutch plate and the driven clutch plate are in a rotatably fitted state, rainwater, dust, etc. are difficult to enter the inside, and moreover, other than the bottle and the coil spring, Since it is made of synthetic resin material, there is no failure such as inability to start due to the occurrence of "rust", and it is easy to assemble, has little variation in locking force, and has excellent wear resistance. .

[Brief explanation of drawings]

1 and 2 show the structure of a conventional electric telescopic antenna clutch, in which FIG. 1 is a plan view, FIG. 2 is a partially sectional side view, and FIGS. 8g3 to 7 are all in accordance with the present invention. Fig. 3 shows a plan view of the active clutch plate;
The same figure (Q is a cross-sectional view taken along the line A-A in the same figure (A), Figure 4 (
A) is a plan view of the driven clutch plate; A sectional view taken along the line C-C in the figure,
FIG. 7 is a diagram showing changes in locking force during one rotation of the active clutch plate. 1 No... Main drive clutch plate, 12... Driven clutch plate, 13... Rotating shaft, 14... Drive gear, 15...
... Output gear, 16... Pin, 17A, 17B, Pressure member, 18... Coil spring. Applicant's agent Patent attorney Takehiko Suzue (A)
-3rd Prisoner (B) Civilian (B)

Claims (1)

[Claims] One of the active clutch plate connected to the drive source side and the driven clutch plate connected to the load side is made into a resin drum-shaped case with a retaining groove formed on the inner peripheral surface, and the other is placed inside the drum-shaped case. It is a resin disc that is rotatably fitted and has four storage parts in the central part, and the four storage parts include an engagement member that engages with the engagement groove, and an inner periphery of the engagement member and the drum-shaped case. 1. A clutch for an electric telescopic antenna, characterized in that a pressure member that applies pressure to a surface and an elastic member that is compressively mounted between these members are housed and arranged.