JP2504985B2 - Rotary fluid damper - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotary fluid damper, and more specifically, a rotary body is rotatably fitted in a fluid-filled case and is applied to the rotary body. The present invention relates to a rotary fluid damper that exerts a damper action that weakens the rotational force by the resistance of the fluid.

[Prior Art] A rotary oil damper using oil such as grease as the fluid is known as a damper of this type.

According to the structure of the conventional rotary oil damper, the surfaces of the case and the rotating body that contact the oil and face each other are flat, and the resistance of the oil to the rotation of the rotating body is the same regardless of the rotation direction. There is.

Therefore, the strength of the damper action according to the rotation direction is the same.

[Problems to be Solved by the Invention] By the way, in various transmission mechanisms for transmitting rotary motion, a strong damper action is required in one direction and a weak damper action in the opposite direction with respect to rotary motion in two directions. Sometimes it is better not to work.

However, since the conventional rotary oil damper has the same strength of the damper action depending on the rotation direction as described above, there is a problem that it cannot be used in such a case.

[Means for Solving Problems] According to the present invention in order to solve such problems, a rotating body is rotatably fitted in a fluid-filled case, and the rotating body is added to the rotating body. In a rotary fluid damper that weakens the rotational force exerted by the resistance of the fluid, the cross-sectional shape of the surface of the rotating body facing the case is
It is configured to include a first orthogonal surface (2a) orthogonal to the rotation direction and a first inclined surface (2b) inclined with respect to the first orthogonal surface, and faces the rotating body. A second orthogonal surface (1a) whose cross-sectional shape is orthogonal to the rotation direction of the rotating body, and a second inclined surface (1b) which is opposite to the first inclined surface of the rotating body. By including so that the fluid is displaced by the first inclined surface with the rotation of the rotating body in the first direction.
1, so that the fluid may flow smoothly along the second inclined surface, and the fluid may contact the first orthogonal surface and the second orthogonal surface as the rotating body rotates in the second direction. We adopted a configuration that increases the resistance difference according to the rotating direction of the rotating body.

[Operation] According to this configuration, when the rotating body is rotated in the first rotation direction, the fluid smoothly flows along the first inclined surface of the rotating body and the second inclined surface of the case. Since it flows, the resistance to rotation is small. On the other hand, when the rotating body is rotated in the second direction, the first orthogonal surface of the rotating body and the second orthogonal surface of the case act so as to sandwich the fluid, so that an extremely large resistance is generated. Can be made. Therefore, the resistance difference depending on the rotating direction of the rotating body can be made extremely large, and the strength of the damper action can be greatly changed depending on the rotating direction.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 are an exploded perspective view illustrating a structure of a rotary oil damper according to an embodiment of the present invention and a perspective view in an assembled state.

The rotary oil damper according to this embodiment includes a case 1, a rotor 2, a cap 3 and an oil 4 (third embodiment) shown in FIG.
(See FIG. 4).

The case 1 supports the entire damper, and is formed in a disk shape having a circular recess 1d. A receiving shaft 1c for rotatably receiving the rotary plate 2 is provided at the center of the bottom surface of the recess 1d.
Are formed. Further, the bottom surface of the recessed portion 1d is formed with unevenness so as to divide the entire 360 ° area around the receiving shaft 1c into 90 ° portions. Each unevenness is formed by an orthogonal surface 1a orthogonal to the rotation direction of the rotary plate 2 indicated by the arrows A and B and an inclined surface 1b inclined with respect to the direction. Highly viscous oil 4 such as grease is filled in the recess 1d, and the rotary plate 2 is rotatably fitted over the oil.

The rotary plate 2 is formed in a disk shape having a diameter slightly smaller than that of the recess 1d. At the center of the rotary plate 2, a rotary shaft 2c is formed integrally with the rotary plate 2 to which a rotational force that should function as a damper in a transmission mechanism incorporating the damper is applied. The rotating shaft 2c is formed not only on the upper surface in FIG. 1 but also on the lower surface in the drawing facing the bottom surface of the recess 1d of the case 1. Further, the lower surface of the rotary plate 2 is formed with unevenness that bisects the entire 360 ° area around the rotary shaft 3c by 180 °. Each unevenness is indicated by an arrow A in the direction of rotation of the rotary plate 2,
It is composed of an orthogonal surface 2a orthogonal to the B direction and an inclined surface 2b inclined to it. The directions of the orthogonal surface 2a and the inclined surface 2b are opposite to those of the orthogonal surface 1a and the inclined surface 1b on the bottom surface of the recess 1d of the case 1.

The rotary plate 2 is a recessed portion of the case 1 filled with the oil 4.
The lower end surface (not shown) of the rotary shaft 2c fitted to the lower surface of the rotary plate and fitted to the rotary plate 1d contacts the upper end surface of the receiving shaft 1c of the case 1 and is rotatably supported. The recesses and protrusions in the recess 1d of the case 1 and the recesses and protrusions on the lower surface of the rotary plate 2 are arranged to face each other with a predetermined gap.

Next, the cap 3 seals the oil 4 and holds the rotary plate 2. The cap 3 is formed in a disk shape having a diameter substantially equal to that of the recess 1d of the case 1, and a hole 3a for passing the rotation shaft 2c of the rotation plate 2 is formed in the center thereof. The cap 3 is fitted and fixed in the recess 1d of the case 1 from above the rotary plate 2 through the rotary shaft 2c in the hole 3a as shown in FIG.

The damper including the above-mentioned members is attached to a transmission mechanism (not shown) with the case 1 fixed, and a rotational force to be subjected to a damper action in the transmission mechanism is applied to the rotary plate 2 via the rotary shaft 2c. The resistance of the oil 4 against the rotation of the rotary plate 2 weakens the rotational force applied to the rotary shaft 2c, so that the damper action is achieved.

Here, in this embodiment, as shown in FIGS. 3 and 4, the surface of the case 1 and the rotating plate 2 which is in contact with the oil 4 is provided with the unevenness composed of the orthogonal surface 1a and the inclined surfaces 1b to 2a, 2b. Therefore, the magnitude of the resistance D of the oil 4 varies depending on the rotation directions A and B of the rotary plate 2.

That is, as shown in FIG. 3, the rotation direction of the rotary plate 2 is A
In the case of the direction, the oil 4 is pushed away by the inclined surface 2b of the rotary plate 2 and smoothly flows along the inclined surfaces 2b and 1b, so that the resistance D becomes relatively small.

On the other hand, as shown in FIG. 4, when the rotation direction is the B direction, the oil 4 is pushed away by the orthogonal surface 2b,
The oil 4 flows so as to hit the orthogonal surfaces 2a and 1a.
Therefore, in this case, the oil 4 is less likely to flow and the resistance D becomes significantly larger than that in the case of FIG.

As described above, according to this embodiment, when the rotation direction is the A direction, the resistance D of the oil is small and the damper action is small. Further, when the rotation direction is the B direction, the resistance D is significantly large and the damper action becomes strong. The strength of the damper action can be changed depending on the rotation direction. Therefore, it can be used very suitably for a transmission mechanism that requires changing the strength of the damper action depending on the rotation direction.

In the above embodiment, the surface of the rotating plate 2 and the case 1 that contact the oil 4 are provided with unevenness, but the unevenness of only one of them makes the resistance of the oil 4 different depending on the direction of rotation. Though it is possible,
In that case, a sufficiently large resistance difference cannot be obtained according to the switching of the rotation direction.

It is also conceivable to use another suitable fluid instead of the oil 4 such as grease.

[Effects of the Invention] As is apparent from the above description, according to the present invention, in the rotary fluid damper, the resistance difference depending on the rotation direction of the rotation of the rotating body can be made extremely large, and depending on the rotation direction. An excellent effect is obtained in that the strength of the damper action can be greatly varied.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing the structure of a rotary oil damper according to an embodiment of the present invention, FIG. 2 is a perspective view showing the assembled state of the damper, and FIGS. 3 and 4 are explanations of the operation of the damper. It is a figure. 1 ... Case, 2 ... Rotating plate 3 ... Cap, 4 ... Oil 1a, 2a ... Orthogonal plane, 1b, 2b ... Inclined plane

Claims (1)

(57) [Claims] 1. A rotary fluid damper configured to rotatably fit a rotating body in a fluid-filled case and weakening a rotational force applied to the rotating body by resistance of the fluid. The rotary fluid damper faces the case. The cross-sectional shape of the surface of the rotating body is defined by a first orthogonal surface (2a) orthogonal to the rotation direction,
And a second inclined surface (2b) that is inclined with respect to the orthogonal surface of, and the cross-sectional shape of the case facing the rotating body is orthogonal to the rotation direction of the rotating body. By including the orthogonal surface (1a) and the second inclined surface (1b) opposite to the first inclined surface of the rotating body, it is possible to rotate the rotating body in the first direction. Accordingly, the fluid is pushed away by the first inclined surface so that the fluid smoothly flows along the first and second inclined surfaces,
With the rotation of the rotating body in the second direction, the fluid hits the first orthogonal surface and the second orthogonal surface to increase the resistance difference according to the rotating direction of the rotating body. And a rotary fluid damper.