JP7152326B2 - Dynamic vibration absorber - Google Patents

Description

The present invention relates to a dynamic vibration absorber that suppresses resonance phenomena in multiple directions on a rotating shaft.

For example, a propeller shaft (rotating shaft) provided in an automobile body is generally provided with a dynamic damper in order to suppress a resonance phenomenon at a specific frequency. Such a dynamic vibration absorber includes a hub attached to the propeller shaft, a vibration ring provided concentrically with the hub on the outer peripheral surface side of the hub, and an elastic body connecting the hub and the vibration ring. (See Patent Documents 1 to 3). In the dynamic vibration absorber configured in this manner, when vibration of a frequency at which the propeller shaft resonates is transmitted, the vibration ring vibrates, thereby exhibiting a function of suppressing resonance of the propeller shaft. In such a dynamic vibration absorber, the vibration ring is designed to suppress resonance of the propeller shaft at least with respect to vibrations in the propeller shaft in the rotational direction (torsional direction).

However, when the vehicle speed increases and the rotation speed of the propeller shaft increases, the centrifugal force acting on the vibrating ring increases, and the vibrating ring may move away from the central axis of the hub. Such behavior is commonly referred to as imbalance. When the imbalance occurs, the dynamic vibration absorber cannot sufficiently exhibit its original vibration suppressing function, and there is also the problem that the durability of the elastic body is impaired. The types of vibrations transmitted to the propeller shaft may include relatively low-frequency vibrations, and the spring constant of the elastic body may be set low as a countermeasure. In such a case, the problem of unbalance as described above becomes more obvious. Therefore, in order to suppress the occurrence of unbalance, a stopper is provided to restrict the radial movement of the vibration ring relative to the hub so that the vibration ring does not become too far away from the central axis of the hub due to centrifugal force. There is (in particular, see Patent Documents 2 and 3).

However, the vibration transmitted to the propeller shaft may include not only the vibration in the rotational direction but also the vibration in the radial direction of the propeller shaft. Further, for example, while the automobile is accelerating after starting, the propeller shaft undergoes vibration called windup vibration in the process of returning to its original state after being deformed so as to sink once. This vibration is a low-frequency vibration, and includes vibration in a tilting direction (twisting direction) with respect to the central axis of the propeller shaft. Therefore, it is desirable to suppress the resonance of these vibrations by using a dynamic vibration absorber. However, in the structure of the conventional stopper, the degree of freedom in the moving direction of the vibrating ring is greatly restricted. Therefore, when a conventional stopper structure is adopted, all vibrations in the rotational direction, radial direction, and direction tilting (twisting direction) with respect to the central axis of the propeller shaft will be resonated by the dynamic vibration absorber. It was difficult to suppress.

JP-A-2002-168293 JP 2007-139041 A JP-A-9-49548 JP 2018-155392 A

An object of the present invention is to suppress resonance not only in the rotational direction and radial direction of the rotating shaft, but also in the tilting direction of the rotating shaft with respect to the central axis of the rotating shaft, while suppressing the occurrence of unbalance. To provide a dynamic vibration absorber capable of

The present invention employs the following means to solve the above problems.

A dynamic vibration reducer of the present invention comprises a hub attached to a rotating shaft, a vibration ring fixed to the hub via a plurality of elastic bodies provided at intervals in the circumferential direction, and fixed to the vibration ring. and a stopper that regulates the amount of radial movement of the vibration ring with respect to the hub,
The vibrating ring is configured to prevent all vibrations of the rotating shaft in the rotational direction, the radial vibration in the rotating shaft, and the tilting direction of the rotating shaft with respect to the central axis of the rotating shaft. Designed to suppress resonance and
The stopper has a regulating portion that abuts against the regulated portion on the outer peripheral surface side of the hub to regulate the amount of movement of the vibration ring in the radial direction with respect to the hub,
The regulating portion has a one-end inclined surface whose distance from the regulated portion widens toward one end in the central axis direction, and a distance from the regulated portion that widens toward the other end in the central axis direction. By providing an inclined surface on the other end side, the vibration ring and the stopper are allowed to move in an inclined direction with respect to the central axis with respect to the regulated portion.

According to the present invention, the stopper restricts the amount of radial movement of the vibration ring with respect to the hub, so that the occurrence of unbalance can be suppressed. Since the vibrating ring and the stopper are allowed to move in the tilting direction with respect to the central axis of the rotating shaft with respect to the regulated portion on the outer wall side of the hub, the vibrating ring moves in the tilting direction of the rotating shaft. resonance against vibration of the rotating shaft can be suppressed.

Here, the hub includes a plate-like portion formed with an insertion hole through which the rotating shaft is inserted, and an annular portion provided around the plate-like portion,
It is preferable that the regulated portion is configured by part of a thin film portion made of an elastic material that covers the outer peripheral surface of the annular portion.

As a result, noise generated when the regulating portion of the stopper collides with the regulated portion can be suppressed.

Further, the stopper preferably includes a cylindrical portion fitted to the outer peripheral surface of the vibration ring, and a plurality of the restriction portions provided at intervals in the circumferential direction on the inner peripheral surface side of the vibration ring. .

In addition, each of the above configurations can be employed in combination as much as possible.

As described above, according to the present invention, while suppressing the occurrence of unbalance, not only the vibration of the rotating shaft in the rotational direction and the radial direction, but also the vibration of the rotating shaft in the tilt direction with respect to the central axis of the rotating shaft can be suppressed. Also, resonance can be suppressed.

FIG. 1 is a front view of a dynamic vibration reducer according to an embodiment of the invention. FIG. 2 is a schematic cross-sectional view of a dynamic vibration reducer according to an embodiment of the invention. FIG. 3 is a schematic cross-sectional view of a dynamic vibration reducer according to an embodiment of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION A mode for carrying out the present invention will be exemplarily described in detail below based on an embodiment with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment are not intended to limit the scope of the present invention only to them, unless otherwise specified. .

(Example)
A dynamic damper according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. FIG. 1 is a front view of a dynamic vibration reducer according to an embodiment of the invention. FIG. 2 is a schematic cross-sectional view of a dynamic vibration reducer according to an embodiment of the present invention, and is a cross-sectional view along AA in FIG. FIG. 3 is a schematic cross-sectional view of a dynamic vibration reducer according to an embodiment of the present invention, and is a cross-sectional view taken along line BB in FIG.

<Application example of dynamic vibration absorber>
The dynamic vibration reducer 100 according to the present embodiment can be suitably used, for example, to suppress resonance of a propeller shaft (rotating shaft) provided in the vehicle body of an automobile. As described in the background art, the propeller shaft can vibrate in each of the rotational direction (twisting direction), the radial direction, and the tilting direction (twisting direction) with respect to the central axis of the propeller shaft. By attaching the dynamic vibration reducer 100 to this propeller shaft, resonance in each of these directions can be suppressed. The dynamic vibration absorber according to the present invention is not limited to such applications, and can be applied to various devices having a rotating shaft that can vibrate in a plurality of directions as described above. can be applied to suppress

<Dynamic vibration absorber>
Particularly, with reference to FIGS. 1 to 3, the dynamic vibration reducer 100 according to this embodiment will be described in more detail. A dynamic vibration reducer 100 according to this embodiment is fixed to a hub 110 attached to a rotating shaft such as a propeller shaft, and to the hub 110 via a plurality of elastic bodies 120 provided at intervals in the circumferential direction. and a vibrating ring 130 . The dynamic vibration reducer 100 also includes a stopper 140 that is fixed to the vibration ring 130 and regulates the amount of radial movement of the vibration ring 130 with respect to the hub 110 . Hub 110, vibration ring 130, and stopper 140 are all made of metal material.

The hub 110 includes a plate-like portion 111 formed with an insertion hole 111 a through which a rotating shaft is inserted, and an annular portion 112 provided around the plate-like portion 111 . The plate-like portion 111 has a shape in which the four corners of a square, when viewed from the front, bulge outward in an arc shape. Along with this, the annular portion 112 provided around the plate-like portion 111 is provided with arc-shaped portions 112a having arc-shaped portions 112a at four locations when viewed from the front. Elastic bodies 120 made of a rubber material are provided between the adjacent arcuate portions 112a. The elastic bodies 120 provided at these four locations are obtained by vulcanization molding. Also, the elastic body 120 is vulcanized and bonded to the hub 110 and the vibration ring 130 respectively. Thereby, the vibration ring 130 is fixed to the hub 110 via the four elastic bodies 120 provided at intervals in the circumferential direction. Further, the outer peripheral surface of the annular portion 112 of the hub 110 is configured to be covered with the material of the elastic body 120 during vulcanization molding. Therefore, the outer peripheral surface of the annular portion 112 is covered with the thin film portion 121 made of the elastic material (the material of the elastic body 120). Needless to say, the elastic body 120 and the thin film portion 121 are integrated.

In the dynamic vibration reducer 100, when the vibration of the frequency at which the rotating shaft resonates is transmitted, the vibration ring 130 vibrates, thereby exhibiting the function of suppressing the resonance of the rotating shaft. In the dynamic vibration absorber 100 according to the present embodiment, vibration in the rotation direction (twisting direction) of the rotation shaft, vibration in the radial direction of the rotation shaft, and tilting direction (prying direction) of the rotation shaft with respect to the central axis of the rotation shaft. Vibration ring 130 is designed to suppress resonance of the rotating shaft for all vibrations.

As described in the background art, in order to suppress the resonance of the propeller shaft as the rotating shaft, it is necessary to take countermeasures against relatively low-frequency vibrations. Therefore, in such a case, it is necessary to use the elastic body 120 with a low spring constant. Therefore, in order to suppress the occurrence of imbalance, the dynamic vibration reducer 100 according to this embodiment is provided with the stopper 140 as described above.

The stopper 140 includes a cylindrical portion 141 fitted to the outer peripheral surface of the vibrating ring 130 and a plurality of restricting portions 142 provided on the inner peripheral surface side of the vibrating ring 130 at intervals in the circumferential direction. In this embodiment, the four restricting portions 142 are provided at positions facing the four arcuate portions 112a provided on the annular portion 112 of the hub 110, respectively. As described above, the outer peripheral surface of annular portion 112 of hub 110 is covered with thin film portion 121 . A portion of the thin film portion 121 that covers the outer peripheral surface of the arcuate portion 112a functions as a portion to be regulated. That is, the regulating portion 142 of the stopper 140 abuts against the regulated portion on the outer peripheral surface side of the hub 110 , thereby regulating the amount of radial movement of the vibration ring 130 with respect to the hub 110 .

In the regulating portion 142 according to the present embodiment, the portion to be regulated (thin film surface of the portion 121), and the other end-side inclined surface 142b, which widens the distance from the regulated portion toward the other end in the direction of the central axis. . As a result, the vibrating ring 130 and the stopper 140 are allowed to move in the tilting direction with respect to the center axis with respect to the regulated portion. Note that in a state where no external force acts on the dynamic vibration reducer 100, there is a minute gap S between the thin film portion 121 and the vicinity of the boundary between the one end side inclined surface 142a and the other end side inclined surface 142b. is formed. However, if it is possible to suppress resonance with respect to vibration in the radial direction of the rotating shaft, the gap S may not be provided. That is, the vicinity of the boundary between the one end side inclined surface 142 a and the other end side inclined surface 142 b may be slightly in contact with the surface of the thin film portion 121 .

<Excellent Points of the Dynamic Vibration Absorber According to the Present Embodiment>
According to the dynamic vibration reducer 100 of this embodiment, the amount of radial movement of the vibration ring 130 with respect to the hub 110 is restricted by the stopper 140, so that the occurrence of imbalance can be suppressed. The vibrating ring 130 and the stopper 140 are allowed to move in the tilting direction with respect to the central axis of the rotating shaft with respect to the portion to be regulated on the outer wall surface side of the hub 110 . That is, while the vicinity of the boundary between the one end side inclined surface 142a and the other end side inclined surface 142b slides on the surface of the thin film portion 121, the restricting portion 142 is inclined with respect to the surface with respect to the central axis. be able to. Therefore, the vibrating ring 130 and the stopper 140 can move with respect to the regulated portion so as to be inclined with respect to the central axis. As a result, the vibration ring 130 can suppress the resonance of the vibration of the rotating shaft in the tilt direction with respect to the central axis of the rotating shaft. As described above, according to the dynamic vibration absorber 100 according to the present embodiment, while suppressing the occurrence of unbalance, not only the vibration in the rotation direction and the radial direction of the rotation shaft but also the inclination of the rotation shaft with respect to the central axis of the rotation shaft Resonance can also be suppressed with respect to directional vibration.

In addition, since the restricting portion 142 of the stopper 140 collides with the thin film portion 121 made of an elastic material covering the outer peripheral surface of the annular portion 112 of the hub 110, the amount of movement of the vibration ring 130 is restricted. , the noise generated at the time of collision can be suppressed.

REFERENCE SIGNS LIST 100 dynamic vibration reducer 110 hub 111 plate-shaped portion 111a insertion hole 112 annular portion 112a arc-shaped portion 120 elastic body 121 thin-film portion 130 vibration ring 140 stopper 141 cylindrical portion 142 restricting portion 142a one-end inclined surface 142b other-end inclined surface

Claims (3)

a hub attached to a rotating shaft; a vibration ring fixed to the hub via a plurality of elastic bodies provided at intervals in the circumferential direction; A dynamic vibration absorber comprising a stopper that regulates the amount of movement of the vibration ring in the radial direction,
The vibrating ring is configured to prevent all vibrations of the rotating shaft in the rotational direction, the radial vibration in the rotating shaft, and the tilting direction of the rotating shaft with respect to the central axis of the rotating shaft. Designed to suppress resonance and
The stopper has a regulating portion that abuts against the regulated portion on the outer peripheral surface side of the hub to regulate the amount of movement of the vibration ring in the radial direction with respect to the hub,
The regulating portion has a one-end inclined surface whose distance from the regulated portion widens toward one end in the central axis direction, and a distance from the regulated portion that widens toward the other end in the central axis direction. and an inclined surface on the other end side, so that the vibration ring and the stopper are allowed to move in an inclination direction with respect to the central axis with respect to the regulated portion. The hub includes a plate-like portion formed with an insertion hole through which the rotating shaft is inserted, and an annular portion provided around the plate-like portion,
2. The dynamic vibration absorber according to claim 1, wherein the regulated portion is formed of a portion of a thin film portion made of an elastic material covering the outer peripheral surface of the annular portion. The stopper includes a cylindrical portion fitted to the outer peripheral surface of the vibration ring, and a plurality of the restriction portions provided at intervals in the circumferential direction on the inner peripheral surface side of the vibration ring. The dynamic vibration absorber according to claim 1 or 2.

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