JPS6383420A - Vibro-isolating bush - Google Patents

Abstract

PURPOSE:To provide unlinear spring constant for a bush and improve the durability thereof by forming a hollow part which is in parallel with the internal wall of an external sleeve in the area between stuck parts of resilient rubber to the external sleeve and also forming a peripheral projection toward the external sleeve on an internal sleeve in the position corresponding to said hollow part. CONSTITUTION:The external peripheral face of a resilient rubber 3 disposed between an internal sleeve 1 and an external sleeve 2, and said sleeve 2 are connected firmly to each other using a sticking part 11 which is in the circumferential direction of a bush. A peripheral projection 13 toward the external sleeve 2 is formed on the internal sleeve 1 at a plurality of positions thereof corresponding to the hollow parts 12. Consequently, when an external pressure P in the direction at right angles with the axis of the bush is applied thereto, a spring constant is low during the time when the external sleeve 2 compresses the hollow part 12 and then becomes high after the external sleeve 2 comes in contact with the resilient rubber 3. The spring constant shows unlinearity with respect to the external pressure at right angles to the axis so that the stopper effect may be enhanced and the durability of the bush be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a vibration-proof bushing for a vehicle which has an elastic rubber inserted and fixed between an inner cylinder and an outer cylinder, and which has a generally cylindrical shape.

BACKGROUND OF THE INVENTION The automobile suspension system shown in FIG. 5 is usually equipped with upper link bushes 15, 15, trailing arm bushes 16, etc., which dampen vibrations from the road surface and transmit them to the vehicle body. There is. As an example of 1986,
Figure 3 is in Publication No. 7009.

An example of the configuration shown in Figure 4 is disclosed. In the figure, 1 is an inner cylinder, 2 is an outer cylinder, and between them there is a generally cylindrical elastic rubber 3.
is inserted and fixed. A projection 1a extending all the way toward the outer cylinder is formed approximately at the center in the axial direction of the inner cylinder 1, and a recess 3&'ll is formed in the elastic rubber 3 at a predetermined position where the projection 1a is formed. be.

According to such a vibration-proof bushing, the external force P in the direction perpendicular to the axis applied between the inner cylinder 1 and the outer case 2 has a small spring constant at the initial stage of compression of the elastic rubber 3, and increases as the compression progresses. The entire circumferential protrusion 1a
It is also possible to provide a characteristic in which the stopper effect of the elastic rubber at a certain part is greater than the stopper effect of the elastic rubber at other parts.

Problems to be Solved by the Invention However, in such a conventional anti-vibration bushing structure, as the external force P increases, a part of the circumferential protrusion 1 and the nearby elastic rubber 3 move in the axial direction Q (Fig. 3). ), the elastic supporting force of the external force P is reduced, the rising reaction force is weakened, and the stopper effect is also weakened. If you try to create a stopper effect by narrowing the gap, the durability of the elastic rubber will be damaged. There was a problem in that when it was spread out, a stopper effect could not be obtained.

Therefore, the present invention solves the problems of the conventional anti-vibration bushings by preventing the elastic rubber from escaping in response to an external force in the direction perpendicular to the axis, maintaining a high elastic supporting force, and reducing the rising reaction. An object of the present invention is to provide a vibration-proof bushing that can increase force while maintaining a high stopper effect against external force.

Ninth means for solving the problem: An elastic rubber is inserted and fixed between the inner cylinder and the outer cylinder, and a rigid N part of the vibration-proof bushing is sandwiched between the elastic rubber and the outer cylinder along the circumferential direction. The elastic rubber located in the gap N along the inner wall of the outer cylinder
51, and protrusions extending all around the outer cylinder toward the outer cylinder are formed at a plurality of locations on the inner cylinder at locations corresponding to the voids.

Operation Due to the formation of the projections all around the circumference, when an external force is applied in the direction perpendicular to the axis of the vibration-proof bushing, while the outer cylinder compresses the cavity, the elastic rubber has a small number of springs, and the outer cylinder and As the elastic rubber comes into contact, the spring constant also increases, resulting in a vibration-proof bushing with a stopper effect. Furthermore, by setting a large distance W& between the bottom surface of the groove formed by the circumferential protrusion and the inner circumferential surface of the outer cylinder, durability can be improved.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings, in which the same parts as those of the conventional structure are denoted by the same reference numerals.

1 and 2 show a basic embodiment of the present invention,
1 is an inner cylinder, and 2 is an outer cylinder, between which a generally cylindrical elastic rubber 3 is inserted and fixed. A fixed portion 11 along the circumferential direction is formed between the outer circumferential surface of the elastic rubber 3 and the outer cylinder 2, and an axial gap 12° 12 is formed in the elastic rubber 3 at a portion sandwiching the fixed portion 11. It is a provision. Furthermore, projections 13, 13 are formed all around the inner tube 1 in the direction of the outer tube 2 at a plurality of locations on the inner tube 1, which correspond to the empty N portions 12, 12. These full-circumference protrusions 13, 13 are machined in advance when manufacturing the inner cylinder 1.

It is obtained by being formed integrally with the inner cylinder l by means such as forging or casting.

According to this anti-vibration bushing, when an external force P in the direction perpendicular to the axis is applied, the elastic rubber 3 has a small spring constant while the outer cylinder 2 compresses the gaps 12, 12! After the external force becomes large and completely compresses the gap 12°12, and the outer wi2 comes into contact with the elastic rubber 3, the elastic rubber 3
changes so that it has a large spring constant l. That is, it becomes possible to maintain a nonlinear spring constant l. Furthermore, the entire circumference protrusion 13
By reducing the thickness of the elastic rubber 3 on , 13, a more rapid stopper effect can be obtained.

As described in the detailed description of the invention, according to the present invention, a gap l along the inner wall of the outer cylinder is provided in the elastic rubber at a portion sandwiching the fixed part along the circumferential direction between the elastic rubber and the outer cylinder; Since a protrusion l extending all around the outer cylinder toward the outer cylinder is formed at the vlPj location of the inner cylinder corresponding to the cavity, the following effects are also achieved. That is, an external force such as a motion applied in a direction perpendicular to the axis between the inner cylinder and the outer cylinder is caused by the gap formed between the elastic rubber and the outer cylinder, which acts as a vibration-proof bushing and exhibits a nonlinear spring constant l. Furthermore, the stopper effect of the elastic rubber at the portion where the circumferential protrusion is formed can be enhanced.

Furthermore, in order to increase the stopper effect, the distance between the bottom surface of the groove formed by the circumferential protrusion and the inner circumferential surface of the outer cylinder is set larger than when the gap between the inner cylinder and the outer cylinder is narrowed. It also has the effect of improving durability.

[Brief explanation of the drawing]

@ Figure 1 is a sectional view of the main part showing Example 7 of the anti-vibration bushing according to the present invention, Fig. 2 is a view taken in the direction of the ■ arrow in Fig. 1, and Fig. 3 is a cross-sectional view of the main part showing an example of the conventional anti-vibration bushing. Figure 4 is I of Figure 3.
FIG. 5 is a cross-sectional view taken along the line V-IV, and a perspective view showing an example of a suspension system for a vehicle. 1... Inner cylinder, 2... Outer cylinder, 3... Elastic rubber, 11
...Fixed portion, 12...Gap portion, 13...Protrusion all around. 2 people Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] (1) In a vibration-proof bushing in which elastic rubber is inserted and fixed between the inner cylinder and the outer cylinder, the elastic rubber at the part that sandwiches the fixed part along the circumferential direction of the elastic rubber and the outer cylinder is attached to the outer cylinder. A vibration damping bushing characterized in that a gap is provided along the inner wall of the cylinder, and protrusions extending all around the inner cylinder toward the outer cylinder are formed at a plurality of locations on the inner cylinder corresponding to the gap.