JPH0240538Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a rotary coupling device.

Rotating coupling devices are commonly used in rotating instruments such as speedometers to transmit rotation from a drive cable.

FIG. 1 is a perspective view of a conventional rotary coupling device.

In the same figure, 1' is a square rod connecting the drive part, 2 is a square hole for fitting the driven part, 3 is a driven part, and the square rod 1' is the driving part.
For example, is rotating in one direction as shown by the arrow.

FIG. 2 is a side sectional view showing a state in which the square connecting rod 1' is fitted into the square fitting hole 2 of the driven part 3.

As shown in the figure, gaps 10 are provided between the connecting square rod 1' and the inner wall 2a of the fitting square hole 2 of the driven part 3.

Therefore, even if the connecting square rod 1' begins to rotate,
The driven part 3 does not rotate immediately, but only after it has rotated by an angle θ, as shown in the cross-sectional view of FIG. , the driven part 3 also starts rotating with a delay.

Since the conventional rotary coupling device was constructed in this way, it had the following drawbacks.

Rotation of the driving part and changes in rotational speed are not smoothly transmitted to the driven part.

Abnormal noise is generated from the rotating connection.

Because the driven part does not rotate smoothly, "pointer wobbling" occurs when used in rotating instruments such as speedometers.

Due to the looseness of the rotating connection, the connection square rod and the driven part are severely worn.

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved rotary coupling device that overcomes the drawbacks of the above-mentioned conventional techniques and can smoothly transmit the rotation of the drive section and changes in rotational speed to the driven section.

Hereinafter, the present invention will be specifically explained with reference to the drawings.

FIG. 4 is a cross-sectional view showing a state in which a square connecting rod used in a rotary connecting device according to an embodiment of the present invention is fitted into a square fitting hole of a driven part.

What is important in FIG. 4 is that the drive unit connecting square rod 1 is made of an elastic body and is twisted at a constant angle in the axial direction. That is, point a at the base end of the ridge line forming each corner of the connecting square rod 1 is at point a' at the tip, point b is at point b', point c is at point c', and point d is at the tip end. correspond to point d′ in a twisted manner.

Note that 4 is a long groove bored in order to adjust the elastic force of the connecting square rod 1.

When this connecting square rod 1 is inserted into the fitting square hole 2 of the driven part 3, two points a-a', bb-b', c-c', As shown in FIG. 5, d-d' is pressed against two adjacent inner walls 2a of the driven portion 3 by torsional elastic force.

As a result, the connecting square rod 1 and the fitting square hole 2 of the driven part 3 are
This eliminates rattling between the inner wall 2a and the transmission of rotation, ensuring accurate and smooth transmission of rotation, which prevents abnormal noise at the connecting part and "pointer wobbling" when used in speedometers, etc., and reduces the degree of wear. can be reduced.

As explained above, according to the present invention, the following effects can be achieved.

Rotation of the driving part and changes in rotational speed are accurately and smoothly transmitted to the driven part.

No abnormal noise is generated from the rotating joint.

When used in speedometers, etc., "needle wobbling" will not occur.

Since there is no play in the rotating connection, wear on the connection square rod and the driven inner wall is reduced.

Since the two points on each ridgeline of the twisted connecting square rod and the two adjacent inner walls of the fitting square hole of the driven part are in only point or linear elastic contact, the fitting square hole of the driven part It is possible to obtain a large fitting pressure without impairing the insertability of the connecting square rod into the connector, and there is no looseness.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of a conventional rotary coupling device, Fig. 2 is a side sectional view of the fitted state, Fig. 3 is a cross-sectional view thereof, and Fig. 4 is a rotary coupling according to an embodiment of the present invention. Perspective view of the drive unit connecting square rod used in the device, No. 5
The figure is a cross-sectional view of the fitted state. 1... Drive unit connection square rod, 2... Fitting square hole, 2a
...Inner wall, 3...Followed part, 4...Long groove, 6,7...
...protrusion, 8, 9... hollow.

Claims (1)

[Claims for Utility Model Registration] In a rotary coupling device in which a square drive part connecting rod is fitted into a square hole for fitting a driven part, the square drive part connecting rod is made of an elastic body, and the square connecting rod of the driving part is made of an elastic body; When the rod is twisted at a certain angle in its axial direction and is fitted into the driven part fitting square hole, the ridge line forming each corner of the driving part connecting square rod and the driven part fitting square hole are adjacent to each other. A rotary coupling device characterized in that two inner walls are brought into elastic contact in a point or a line at two locations spaced apart in the longitudinal direction.