JP2000065112A - Bush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To equalize a spring characteristic in the direction perpendicular to the axis in any part by making preliminary compressive force act even on an inside rubber elastic body by diametrical contraction of an outer cylinder metal fitting by constituting a bush so that the total area of two or more slits becomes equal in any part between the axes drawn in the shaft direction to an intermediate cylinder metal fitting. SOLUTION: A development of an intermediate cylinder metal fitting 5 is shown. Slits 6 inclined in the shaft direction are formed in large numbers. A width of these slits 6 is set to about 1 to 2 mm. Here, two slits 6 are formed so as to overlap each other in the axial direction. When the two axes are drawn in the optional part in a prescribed width in the shaft direction to the intermediate cylinder metal fitting 5, two or more slits are contained between the axes, and the total of the respective areas of the slits 6 between the axes is almost equally constituted. An inclination in the shaft direction of the slits 6 is desirably within a range of 40 to 60 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a bush having a triple cylinder structure.

[0002]

2. Description of the Related Art In general, when a rubber elastic body is interposed between an inner cylinder and an outer cylinder, the outer cylinder is reduced in diameter in order to increase the interfacial strength and adhesive strength of the rubber. It has been practiced to provide a pre-compression force. In addition, an intermediate cylinder is provided between the inner cylinder and the outer cylinder in order to increase the spring constant and suppress excessive deformation of the rubber in comparison with the double cylinder. ing. Even with this triple structure, the outer cylinder is reduced in diameter to give a pre-compression force to the rubber,
There is a disadvantage that a sufficient compressive force does not act on the rubber between the intermediate cylindrical member and the inner cylindrical member. In order to solve such a disadvantage, a bush as shown in FIGS. 4 and 5 has been developed.

In the conventional example shown in FIG. 4, an inner cylinder 1, an intermediate cylinder 100, and an outer cylinder 2 are arranged concentrically.
Rubber elastic bodies 3 and 4 are interposed between 100 and 2 respectively. As shown in FIG. 5, the intermediate cylindrical fitting 100 has a large number of slits 101 formed alternately from both ends along the axial direction, and the slit 101 from one end and the slit 101 from the other end have a length of l. Only overlap.

[0004]

A conventional intermediate tube fitting 10
0 is the outer cylinder 2
Of the intermediate cylinder 100
Can also be deformed inward and the inner rubber elastic body 3 can also be pre-compressed. However, since the slit 101 is formed along the axial direction, when used as a bush, the spring characteristics of the rubber elastic bodies 3 and 4 acting in the direction perpendicular to the axis differ depending on the location where the slit 101 exists and the location where the slit 101 does not exist. There was an inconvenience of being different.

In view of the above, the present invention provides a method in which a sufficient pre-compression force is applied to the inner rubber elastic body by reducing the diameter of the outer cylinder, and the spring characteristic of the compressed rubber elastic body in the direction perpendicular to the axis is determined. However, the purpose is to provide a bush that is almost the same.

[0006]

In order to achieve the above-mentioned object, the present invention provides an inner cylinder, an intermediate cylinder, and an outer cylinder which are concentrically arranged, and a rubber elastic body is interposed between the respective brackets. In the bush, a large number of slits are formed in the middle tube fitting with respect to the axial direction, and two or more slits are included between the axes when two axes are drawn with a predetermined width in the axial direction with respect to the middle tube fitting. And the total area of the slits between the axes is almost equal in any part.

[0007]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an exploded view of the intermediate cylindrical fitting 5, in which a number of slits 6 inclined with respect to the axial direction are formed.
The width of these slits 6 is about 1 to 2 mm. In this embodiment, two slits 6 are formed so as to overlap in the axial direction. As shown in FIG. 2, when two axes a and b are drawn at an arbitrary portion with a predetermined width in the axial direction with respect to the intermediate cylindrical fitting 5, two or more slits 6 are included between the axes a and b. And the sum of the respective areas 61 and 62 of the slits 6 between the axes a and b and the areas 63 and 6 in other portions.
4 so that the sum of the four is substantially equal. The inclination angle of the slit 6 with respect to the axial direction is preferably in the range of 40 ° to 60 °. The axes a and b are parallel to the central axis of the intermediate cylindrical member 5 and pass on the periphery of the intermediate cylindrical member 5.

The outer diameter of the intermediate cylindrical fitting 5 shown in FIGS. 1 and 2 was 33 mm, and the height H was 40 mm. When the outer cylinder 2 is reduced in diameter, the outer diameter of the intermediate cylinder 5 is also reduced.

FIG. 3 shows a cross section of the bush after the outer cylinder 2 has been drawn using the intermediate cylinder 5 shown in FIGS. Although shown in FIG. 3 to clarify the portion of the slit 6, the rubber elastic bodies 3 and 4 enter the slit 6 after the outer metal fitting 2 is drawn, so that the slit as a gap as shown in FIG. 6 does not appear.

[0011]

As described above, according to the present invention, a large number of slits inclined with respect to the axial direction are formed, and when two axes are drawn with a predetermined width in the axial direction with respect to the intermediate cylindrical fitting. Since two or more slits are included between the axes and the total area of the slits between the axes is almost equal in any part, the inner rubber elastic body is also pre-compressed by reducing the diameter of the outer cylinder. The bush after pre-compression has the same spring characteristics in any direction perpendicular to the axis.

[Brief description of the drawings]

FIG. 1 is a development view of an intermediate cylindrical metal fitting used in the present invention.

FIG. 2 is a front view of an intermediate cylindrical fitting.

FIG. 3 is a sectional view of a bush.

FIG. 4 is a sectional view showing a conventional example.

FIG. 5 is a perspective view showing an intermediate cylinder fitting used in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner cylinder metal fitting 2 Outer cylinder metal fitting 3, 4 Rubber elastic body 5 Intermediate cylinder metal fitting 6 Slit

Claims (1)

[Claims] 1. A bush in which an inner cylinder, an intermediate cylinder, and an outer cylinder are concentrically arranged, and a rubber elastic body is interposed between the respective metal fittings. Are formed, and when two axes are drawn with a predetermined width in the axial direction with respect to the intermediate cylindrical fitting, two or more slits are included between the axes and the total area of the slits between the axes becomes almost equal in any part. A bush characterized by being configured as described above.