JP2022083084A - Torsional damper - Google Patents

Abstract

To provide a torsional damper which can be set in a narrower range when subjected to impact, while keeping the degree of freedom in design high.SOLUTION: A damper body 200 is fixed to a hub 100 with the inner peripheral face of a sleeve 210 pressed into the outer peripheral face of a second cylindrical part 140. The damper body 200 is fixed to the hub 100 in the state of protruding to the opposite side to a first cylindrical part 110 with respect to the second cylindrical part 140 in the axial direction, and in the state of being able to slide to the first cylindrical part 110 side when the damper body 200 is subjected to impact from the second cylindrical part 140 side toward the first cylindrical part 110 side in the axial direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to a torsional damper used to reduce torsional vibration generated in a crankshaft (rotary drive shaft) of an automobile engine.

A torsional damper is attached to the crankshaft of the engine in order to reduce its torsional vibration. The torsional damper according to the conventional example will be described with reference to FIG. FIG. 3 is a cross-sectional view showing a state in which the torsional damper according to the conventional example is attached to the crankshaft.

The torsional damper 500 integrally includes a hub 510 fixed to the crankshaft 20 by a bolt 30, a vibration ring 530, and a rubber-like elastic body 520 provided between the hub 510 and the vibration ring 530. There is. Further, a first pulley 511 is provided on the outer peripheral surface of the hub 510, and a second pulley 531 is provided on the outer peripheral surface of the vibration ring 530.

Here, the vehicle body of an automobile is provided with a space called a crushable zone in order to cushion the impact when the vehicle body receives an impact. Therefore, various members in the vehicle body need to be contained in a predetermined region when subjected to an impact. In recent years, the installation space for torsional dampers has tended to become narrower due to the effects of overcrowding of engine rooms. For example, in the conventional example shown in FIG. 3, when the torsional damper 500 is impacted at least, it may be required to accommodate the torsional damper 500 on the arrow side of the thick dotted lines L1 and L2. However, when the torsional damper 500 is made smaller, the moment of inertia of the vibration ring 530 becomes smaller, so that the degree of freedom in design becomes narrower, and it becomes difficult to fully exert the vibration absorption effect. Further, since the torsional damper 500 has high rigidity, it will not be deformed or damaged even if it receives a certain impact, and the torsional damper 500 cannot be accommodated in a predetermined region.

Japanese Unexamined Patent Publication No. 2014-52061 Japanese Unexamined Patent Publication No. 7-310787

An object of the present invention is to provide a torsional damper that can be contained in a narrower range when subjected to an impact while maintaining a high degree of freedom in design.

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

The torsional damper of the present invention is
A torsional damper including a hub attached to a crankshaft and a damper body provided concentrically with the hub.
The hub is concentrically with the first cylindrical portion at a position axially offset from the first cylindrical portion and radially outside the first cylindrical portion with the first cylindrical portion fixed to the crankshaft. It has a second cylindrical portion provided and has.
The damper body integrally has a sleeve, a vibrating ring provided concentrically outward with the sleeve, and a rubber-like elastic body provided between the sleeve and the vibrating ring.
The damper body is fixed to the hub by pressing the inner peripheral surface of the sleeve into the outer peripheral surface of the second cylindrical portion, and is fixed to the hub.
The damper body protrudes from the second cylinder portion on the side opposite to the first cylinder portion in the axial direction, and the damper body faces from the second cylinder portion side to the first cylinder portion side in the axial direction. It is characterized in that it is fixed to the hub in a state where it can slide toward the first cylindrical portion side when it receives an impact.

According to the present invention, when the damper main body receives an impact, it slides toward the first cylindrical portion, so that the entire torsional damper can be accommodated in a narrower area when the impact is received. On the other hand, in the state before receiving the impact, the damper main body is fixed to the hub in a state of protruding from the second cylindrical portion on the side opposite to the first cylindrical portion in the axial direction. Therefore, the moment of inertia of the damper body can be increased, and the degree of freedom in design can be increased. As a result, the vibration absorption effect can be fully exerted.

The hub has an outward flange portion provided at an end portion on the second cylindrical portion side in the axial direction of the first cylindrical portion, and a first pulley provided at the radial outer tip of the outward flange portion. Cylinder,
The second cylindrical portion may be provided radially outside the first pulley.

Further, the outer peripheral surface of the vibration ring may be formed by a second pulley.

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

As described above, according to the present invention, it is possible to fit the torsional damper within a narrower range when it receives an impact while maintaining a high degree of freedom in designing the torsional damper.

FIG. 1 is a cross-sectional view showing a state in which the torsional damper according to the present embodiment is fixed to the crankshaft in a normal state. FIG. 2 is a cross-sectional view showing a state of the torsional damper according to the present embodiment when receiving an impact. FIG. 3 is a cross-sectional view showing a state in which the torsional damper according to the conventional example is attached to the crankshaft.

Hereinafter, embodiments for carrying out the present invention will be described in detail exemplary 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 to those alone unless otherwise specified. ..

(Example)
The torsional damper according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2. 1 and 2 are cross-sectional views showing a state in which the torsional damper according to the present embodiment is fixed to the crankshaft, FIG. 1 is a normal state, and FIG. 2 is a state in which the torsional damper is impacted. Shows. The torsional damper has a substantially rotationally symmetric shape, and is shown in FIGS.
In No. 2, a cross section obtained by cutting the torsional damper is shown on the surface including the central axis of the torsional damper.

<Tortional damper>
The torsional damper 10 according to the present embodiment includes a hub 100 attached to the crankshaft 20 and a damper main body 200 provided concentrically with the hub 100.

The hub 100 is a metal annular member. The hub 100 is provided at a first cylindrical portion 110 fixed to the crankshaft 20, an outward flange portion 120 provided on one end side of the first cylindrical portion 110, and a radial outer tip of the outward flange portion 120. It includes a first pulley 130 and a second cylindrical portion 140.

A boss or the like is provided on the inner peripheral surface side of the first cylindrical portion 110, and is fixed to the crankshaft 20 by bolts 30. In this embodiment, the first cylindrical portion 110 is directly attached to the crankshaft 20. However, the present invention also includes a case where the hub is indirectly attached to the crankshaft via, for example, a member such as a sleeve provided on the outer peripheral surface side of the crankshaft. The second cylindrical portion 140 is provided concentrically with the first cylindrical portion 110 at a position offset in the axial direction with respect to the first cylindrical portion 110 and radially outside the first cylindrical portion 110 and the first pulley 130. It is configured to be. The outward flange portion 120 is provided at the end of the first cylindrical portion 110 on the side of the second cylindrical portion 140 in the axial direction.

The damper body 200 includes a metal sleeve 210, a metal vibrating ring 230 concentrically provided on the radially outer side of the sleeve 210, and a rubber-like elastic body 220 provided between the sleeve 210 and the vibrating ring 230. Is integrally possessed. The sleeve 210 is composed of a cylindrical member. The outer peripheral surface of the vibrating ring 230 is composed of a second pulley 231. The rubber-like elastic body 220 provided in an annular shape is provided in a state of being press-fitted between the outer peripheral surface of the sleeve 210 and the inner peripheral surface of the vibration ring 230. The rubber-like elastic body 220 is obtained by vulcanization molding. As the material of the rubber-like elastic body 220, ethylene propylene rubber (EPDM) having excellent durability, heat resistance, vibration reducing effect and the like can be preferably used.

The damper main body 200 configured as described above is fixed to the hub 100 by press-fitting the inner peripheral surface of the sleeve 210 into the outer peripheral surface of the second cylindrical portion 140. Then, the damper main body 200 is fixed to the hub 100 in a state of protruding from the second cylindrical portion 140 on the side opposite to the first cylindrical portion 110 in the axial direction. Further, the damper main body 200 is in a state where it can slide toward the first cylindrical portion 110 when the damper main body 200 receives an impact from the second cylindrical portion 140 side toward the first cylindrical portion 110 side in the axial direction. It is fixed to the hub 100. That is, when the damper main body 200 receives a predetermined impact (axial load) or more in the arrow X direction in FIG. 2 from the normal state shown in FIG. 1, the damper main body 200 slides toward the first cylindrical portion 110 side.

Here, in order to satisfy the function as the torsional damper 10, the dimensions and materials of each member, the press-fitting amount (the dimension in the axial direction in the region where the sleeve 210 and the second cylindrical portion 140 are in contact), and the like are as follows. It is desirable to set as follows. That is, it is desirable that the sleeve 210 and the second cylindrical portion 140 are set so as not to slide within the range of the load acting on the damper main body 200 during normal operation of the automobile. On the other hand, when the damper body 200 receives an impact of a predetermined value or more (for example, a load in the axial direction is 20 kN or more), the sleeve 210 and the second cylindrical portion 140 slide, and the damper body 200 slides. It is desirable to set it so that it slides toward the first cylindrical portion 110 side.

<Advantages of torsional dampers according to this embodiment>
According to the torsional damper 10 according to the present embodiment, when the damper main body 200 receives an impact of a predetermined value or more, it slides toward the first cylindrical portion 110 side. As a result, in the event of an impact, the entire torsional damper 10 can be accommodated in a narrower area. As a result, as explained in the background technique, the torsional damper 10 is accommodated on the arrow side of the thick dotted lines L1 and L2 in FIG. 2 when it receives an impact due to the necessity of providing a crushable zone. Even if it is required, this request can be met. In addition, the impact on the engine body provided with the crankshaft can be suppressed.

On the other hand, in the state before receiving the impact (normal state), the damper main body 200 protrudes from the second cylindrical portion 140 to the opposite side of the first cylindrical portion 110 in the axial direction to the hub 100. It is fixed. As a result, the damper main body 200 protrudes to the outside of the thick dotted line L1 (see FIG. 1). With such a configuration, the damper main body 200 can be arranged at a position further away from the fixed portion (fixed portion by the first cylindrical portion 110) of the torsional damper 10 with respect to the crankshaft 20. This makes it possible to increase the moment of inertia. Therefore, in the used state, the degree of freedom in design can be increased as compared with the case where the entire torsional damper 10 is arranged on the arrow side of the dotted lines L1 and L2. As a result, the vibration absorption effect can be fully exerted. The torsional damper 10 exhibits a function of suppressing the resonance of the crankshaft 20 by vibrating the vibration ring 230 when the vibration of the frequency at which the crankshaft 20 resonates is transmitted. In the torsional damper 10 according to the present embodiment, the damper body 200 is designed so as to suppress the resonance of the crankshaft 20 with respect to the vibration in the rotation direction (twisting direction) of the crankshaft 20.

10 Tortional damper 20 Crankshaft 30 Bolt 100 Hub 110 1st cylindrical part 120 Outward flange part 130 1st pulley 140 2nd cylindrical part 200 Damper body 210 Sleeve 220 Rubber elastic body 230 Vibration ring 231 2nd pulley

Claims (3)

A torsional damper including a hub attached to a crankshaft and a damper body provided concentrically with the hub.
The hub is concentrically with the first cylindrical portion at a position axially offset from the first cylindrical portion and radially outside the first cylindrical portion with the first cylindrical portion fixed to the crankshaft. It has a second cylindrical portion provided and has.
The damper body integrally has a sleeve, a vibrating ring provided concentrically outward with the sleeve, and a rubber-like elastic body provided between the sleeve and the vibrating ring.
The damper body is fixed to the hub by pressing the inner peripheral surface of the sleeve into the outer peripheral surface of the second cylindrical portion, and is fixed to the hub.
The damper body protrudes from the second cylinder portion on the side opposite to the first cylinder portion in the axial direction, and the damper body faces from the second cylinder portion side to the first cylinder portion side in the axial direction. A torsional damper characterized in that it is fixed to the hub in a state where it can slide toward the first cylindrical portion when it receives an impact. The hub has an outward flange portion provided at an end portion on the second cylindrical portion side in the axial direction of the first cylindrical portion, and a first pulley provided at the radial outer tip of the outward flange portion. Cylinder,
The torsional damper according to claim 1, wherein the second cylindrical portion is provided radially outside the first pulley. The torsional damper according to claim 1 or 2, wherein the outer peripheral surface of the vibrating ring is composed of a second pulley.

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