JPH0724676Y2 - damper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an improvement in a damper that absorbs and suppresses vibrations generated in various rotary shaft systems such as a crankshaft of an internal combustion engine.

[Conventional technology]

Conventionally, as shown in FIG. 3, a hub (1) fitted to a crankshaft of an automobile engine is integrally provided with a radially rising portion (1a) and a rim portion (1b), and a rim portion (1) is provided.
The mass bodies (2) are concentrically spaced apart from each other on the inner peripheral side of b), and the spring member (3) is arranged between the hub (1) and the mass body (2) so that both (1) and (2) There is known a torsional damper in which is elastically connected. The hub (1) and the mass body (2) are each formed in a ring shape from a predetermined metal, and a pulley groove (1c) is provided on the outer peripheral surface of the rim portion (1b) of the hub (1). The spring member (3) is formed into an annular shape by a predetermined rubber-like elastic material, and has a radial portion (3a) and a cylindrical portion (3b) integrally formed to have a substantially L-shaped cross section and a rising portion (1a). ) Is vulcanized and adhered to one end surface in the axial direction, the inner peripheral surface of the rim portion (1b), and the other end surface and the outer peripheral surface of the mass body (2) in the axial direction.

[Problems to be solved by the device]

The damper configured as described above constitutes a kind of resonance system with respect to the crankshaft to absorb and suppress the vibration generated in this shaft, but the following problems have been pointed out from the configuration.

That is, according to the damper having the above-described configuration, the cylindrical space (3b) of the spring member (3) is filled in the annular space between the rim portion (1b) of the hub (1) and the mass body (2) without any gap. Therefore, the spring constant in the bending direction (perpendicular to the rotation axis) of the spring member (3) inevitably increases, and the natural frequency in the same direction also increases (generally 1000 to 2000 Hz), which occurs in the crankshaft. There is a problem that it is not possible to sufficiently deal with the bending vibration (vibration acting in the direction perpendicular to the rotation axis, which is generally 200 to 400 Hz).

[Means for Solving the Problems]

In view of the above points, the present invention has been devised to solve the above-mentioned problems in the prior art, and in order to achieve this object, a hub in which a radial rising portion and a rim portion are integrally provided A mass body that is concentrically spaced apart from each other on the inner peripheral side of the rim portion, and a radial portion and a cylindrical portion that are integrally provided to have a substantially L-shaped cross-section. A spring member made of a rubber-like elastic material adhered to the inner peripheral surface of the portion and the other axial end surface and outer peripheral surface of the mass body,
And a plurality of hollow portions arranged in the circumferential direction are provided in the cylindrical portion.

[Action]

When the cylindrical portion of the spring member is provided with a plurality of cavities arranged side by side in the circumferential direction, the stiffness of the spring member is weakened, and the natural frequency in the bending direction is reduced accordingly. Further, since the cylindrical portion of the spring member is not completely removed, it is possible to prevent the mass body from colliding with the rim portion of the hub during operation by using the remaining portion of this cylindrical portion as a support (excessive eccentricity is avoided. Can be prevented).

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the torsional damper according to the embodiment has a hub (1) integrally provided with a radial rising portion (1a) and a rim portion (1b) and a rim portion (1). A mass body (2) concentrically arranged on the inner peripheral side of 1b), a radial portion (3a) and a cylindrical portion (3b) are integrally provided to have a substantially L-shaped cross section and a rising portion (1a). ), One end surface in the axial direction, the inner peripheral surface of the rim portion (1b), and the other end surface and the outer peripheral surface of the mass body (2) in the axial direction, the spring member (3) made of a rubber-like elastic material. It has a cylindrical part (3
In b), a plurality of cavities (3c) arranged in the circumferential direction are provided. The hollow portion (3c) is open at one end face in the axial direction of the cylindrical portion (3b), and the openings having a substantially oval shape are arranged in a circumferentially equidistant pattern.

In the torsional damper having the above-described configuration, the rigidity of the spring member (3) in the bending direction is improved by providing the hollow portion (3c) arranged in the circumferential direction in the cylindrical portion (3b) of the spring member (3). Can be weakened to lower the natural frequency, and the cavity (3
The natural frequency can be adjusted arbitrarily by changing the number and size of a). It is also possible to adjust the natural frequency by forming the hollow portions (3a) to a predetermined number and size and then filling the hollow portions (3a) with a filler during use. That is, for example, by using rubber of the same material as or a material different from that of the main body of the spring member (3), a plurality of piece-shaped fillers having a size to be press-fitted into one cavity (3a) are prepared. Fill the cavity (3a) with this filler, such as every other or every two,
This adjusts the natural frequency. It is also conceivable to mold the filler with a heavy material such as metal to adjust the mass on the side of the mass body (2).

Further, according to the torsional damper having the above structure, the cylindrical portion (3b) of the spring member (3) is not completely removed. Therefore, the remaining portion of the cylindrical portion (3b) is used as a support to support the mass body. It is possible to prevent (2) from colliding with the rim portion (1b) of the hub (1) during operation (excessive eccentricity can be prevented).

[Effect of device]

 The present invention has the following effects.

That is, by providing a plurality of cavities arranged side by side in the circumferential direction in the cylindrical portion of the spring member, the spring constant in the bending direction of the spring member is reduced, and the natural frequency in the same direction is reduced accordingly. You can Therefore, this makes it possible to effectively absorb the bending vibration. Moreover, irrespective of this, it is possible to prevent the mass body from colliding with the rim portion of the hub during operation by using the remaining portion of the cylindrical portion as a support (excessive eccentricity can be prevented).

[Brief description of drawings]

1 is a half sectional view of a damper according to an embodiment of the present invention, FIG. 2 is a half sectional side view of the damper, and FIG. 3 is a half sectional view of a conventional damper. (1) Hub, (1a) Rise, (1b) Rim, (1c)
Pulley groove, (2) mass body, (3) spring member, (3a) radial portion, (3b) cylindrical portion, (3c) hollow portion

Claims (1)

[Scope of utility model registration request] 1. A hub (1) integrally provided with a rising portion (1a) in the radial direction and a rim portion (1b), and the rim portion (1b).
The mass body (2), which is concentrically disposed on the inner peripheral side, is integrally provided with the radial portion (3a) and the cylindrical portion (3b) to have a substantially L-shaped cross section, and the rising portion (1a) One end face in the axial direction,
And a spring member (3) made of a rubber-like elastic material adhered to the inner peripheral surface of the rim portion (1b) and the other axial end surface and outer peripheral surface of the mass body (2), and the cylindrical portion ( A damper having a plurality of cavities (3c) arranged in the circumferential direction in (3b).