JPH0144828Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to an improvement of a vibration-proof bushing disposed at a support portion of a rear suspension arm in a vehicle suspension system.

(Prior art) This type of anti-vibration bushing consists of a small-diameter inner cylindrical body into which a horizontal support pin supported by a bracket fixed to the vehicle body is inserted, and a press-fit fixation to the end of the rear suspension arm. It is mainly composed of a large-diameter outer cylindrical body surrounding the inner cylindrical body, and an elastic body interposed between the inner and outer cylindrical bodies to connect the two cylindrical bodies. This anti-vibration bushing is required to have anti-vibration properties to alleviate vibrations received from the road surface while the vehicle is running, and durability to withstand repeated vibration loads. Conventionally,
In order to satisfy both vibration isolation and durability, the fifth
As shown in the figure, a hollow portion 5' having an arcuate cross section is provided in an elastic body 4' interposed between the inner and outer cylindrical bodies 2' and 3'.
However, there are some that are installed oppositely and in the direction of the center line of both the inner and outer cylinders 2', 3'.

(Problems to be solved by the invention) As shown in Fig. 6, the above-mentioned conventional spring has a nonlinear spring characteristic in which the spring constant is low when a low load is input, and the spring constant is high when a high load is input. However, this has the problem that the degree of non-linearity increases and that a hitting sound may be generated when the inner and outer arcuate surfaces of the hollow portion 5' of the elastic body 4' collide.

In view of the above-mentioned conventional problems, the purpose of this invention is to obtain smooth non-linear spring characteristics with a minimum number of members without complicating the structure, and to prevent the generation of hammering sounds. The purpose of the present invention is to provide an anti-vibration bushing.

(Means for Solving the Problems) In order to achieve the above object, this invention consists of a small-diameter inner cylinder, a large-diameter outer cylinder surrounding it, and an intervening body between the inner and outer cylinders. an elastic body that connects the two cylindrical bodies, and a hollow part having a substantially arcuate cross section is provided in the elastic body in opposing directions in the direction of the center line of both the inner and outer cylindrical bodies; The anti-vibration bushing has a protrusion formed on at least one of both the inner and outer arcuate surfaces of the hollow portion and protrudes toward the other arcuate surface at approximately the center of the arc, Furthermore, the protrusion is formed in a sloping shape with a high center part and low both ends in a cross section in the center line direction of the cylindrical body. Only the top part is always in contact with the other arcuate surface, while a gap is provided between both ends of the protrusion other than the central apex and the other arcuate surface based on the inclined surface of the protrusion. This is what I did.

(Function) In the anti-vibration bushing configured as described above, a projection protruding toward the other arcuate surface is formed on one of the inner and outer arcuate surfaces of the hollow portion of the elastic body. Smooth nonlinear spring characteristics can be obtained.

Furthermore, the protrusion is formed in a sloping shape with a high center part and low both ends in a cross section in the center line direction of the cylindrical body. Only the top part is always in contact with the other arcuate surface, while a gap is provided between both ends of the protrusion other than the central top part and the other arcuate surface based on the inclined surface of the protrusion. It is possible to prevent the occurrence of hitting sounds caused by collision between the inner and outer arcuate surfaces in the hollow portion of the elastic body.

Furthermore, the prying stiffness when the mutual center lines of the inner and outer cylinders are inclined can be reduced by the gap between both ends of the protrusion and the other circular arc surface.

(Example) An example of this invention will be described below with reference to the drawings.

In FIG. 1 showing an axial cross section and FIG. 2 showing a radial cross section of a vibration isolating bushing 1 mainly composed of inner and outer cylinders 2, 3 and an elastic body 4, a small diameter inner cylinder is shown. 2 is assembled to a bracket B fixed at a predetermined position on the vehicle body by means of a horizontal support pin A fitted into its center hole.

A large-diameter outer cylinder 3 surrounding the inner cylinder 2 is press-fitted and fixed to the end of the rear suspension arm C.

An elastic body 4 is interposed between the inner cylinder 2 and the outer cylinder 3 and connects the inner and outer cylinders 2 and 3.
It is vulcanized and molded from a rubber material with a predetermined hardness. The elastic body 4 includes a pair of hollow portions 5 having a substantially arcuate cross section;
5 are provided oppositely and penetrating the inner and outer cylindrical bodies 2 and 3 in the center line direction. Furthermore, in the radial cross-section of the elastic body 4, of the two arcuate surfaces of the hollow portion 5, approximately at the center of the inner arcuate surface, as shown in FIG. A mountain-shaped protrusion 6 is formed. Further, in this embodiment, in the axial cross section of the elastic body 4, both the inner and outer circular arc surfaces of the hollow portion 5 are as shown in FIG.
It is formed into a gentle mountain shape with a high central portion and low side portions, and only the central portions of these two mountain-shaped cross sections are always in contact with each other.

Note that when the elastic body 4 is vulcanized between the inner and outer cylindrical bodies 2 and 3, as shown in FIG.
A predetermined gap is created between the outer circular arc surface and the inner arc surface by drawing the outer cylinder 3 and reducing its diameter by a predetermined amount. The protrusion 6 always comes into contact with the outer arcuate surface.

The anti-vibration bushing 1 of this embodiment is constructed as described above, and therefore, when a load is applied from the rear suspension arm C side in the direction of arrow P in FIG. is the hollow part 5
flexes with a small spring characteristic until the protrusion 6 is elastically compressed by a predetermined amount. Furthermore, the protrusion 6 of the hollow part 5
After being elastically compressed by a predetermined amount, it deflects with successive spring characteristics. Therefore, as shown in FIG. 4, a nonlinear spring characteristic is obtained in which the spring constant is low when a low load is input, and the spring constant is high when a high load is input, and the degree of nonlinearity is also smooth.

Furthermore, since the protrusion 6 of the inner arcuate surface of the hollow portion 5 of the elastic body 4 is always in contact with the outer arcuate surface, the collision between these two arcuate surfaces can be resolved and the generation of tapping noise can be prevented. I can do it.

(Effects of the invention) As described above, according to this invention, smooth nonlinear spring characteristics can be obtained by the protrusion formed on one of the inner and outer arcuate surfaces of the hollow part of the elastic body. It will be done.

Furthermore, when the anti-vibration bushing is rested and assembled, only the central top of the protrusion is always in contact with the other arcuate surface, so collision between both the inner and outer arcuate surfaces in the hollow part of the elastic body is the cause. It is possible to prevent the occurrence of hitting sounds.

Moreover, when the mutual center lines of the inner and outer cylinders are tilted, the prying stiffness can be reduced by the gap between both ends of the protrusion and the other circular arc surface, resulting in poor riding comfort. I have nothing to do.

As a result, smooth non-linear spring characteristics can be obtained with a minimum number of members without complicating the structure or deteriorating riding comfort, and it is possible to prevent abnormal noises caused by hitting sounds. effective.

[Brief explanation of the drawing]

The drawing shows one embodiment of this invention.
The figure is an axial cross-sectional view of the anti-vibration bushing, and Figure 2 is the 1st
FIG. 3 is a radial sectional view taken along the - line in the figure, FIG. 3 is a radial sectional view showing a state in which an elastic body is vulcanized between the inner and outer cylinders, and FIG. 4 is a spring characteristic diagram. Figures 5 and 6 show the conventional one.
FIG. 5 is a radial sectional view, and FIG. 6 is a spring characteristic diagram. DESCRIPTION OF SYMBOLS 1... Anti-vibration bushing, 2... Inner cylindrical body, 3... Outer cylindrical body, 4... Elastic body, 5... Hollow part, 6... Protrusion part.

Claims (1)

[Claims for Utility Model Registration] A small-diameter inner cylinder, a large-diameter outer cylinder surrounding it, and an elastic body interposed between the inner and outer cylinders to connect the two cylinders. In the elastic body, hollow portions having a substantially arcuate cross section are provided oppositely in the direction of the center line of both the inner and outer cylinders, and in the elastic body,
The anti-vibration bushing has a protrusion formed on at least one of the inner and outer arcuate surfaces of the hollow portion and protrudes toward the other arcuate surface at approximately the center of the arcuate surface, further comprising: The protrusion is formed in a sloping shape with a high center and low ends at both ends in a cross section in the center line direction of the cylindrical body. is always in contact with the other arcuate surface, while a gap is provided between both ends of the protrusion other than the central apex and the other arcuate surface based on the inclined surface of the protrusion. Anti-vibration bushing.