JP3675147B2 - Cylindrical vibration isolator - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cylindrical vibration isolator.
[0002]
[Prior art and problems to be solved by the invention]
2. Description of the Related Art Conventionally, as a cylindrical vibration isolator, generally, both an inner cylinder fitting and an outer cylinder fitting are cylindrical. Such an anti-vibration device generates a tensile stress due to the rubber elastic body after vulcanization molding of the rubber elastic body, thereby reducing durability. Therefore, in order to remove such a tensile stress, After vulcanization bonding, the outer cylinder fitting is drawn.
[0003]
By the way, there is also a cylindrical vibration isolator in which the inner cylinder fitting and the outer cylinder fitting are deformed in accordance with the mating member, and there is a demand for drawing processing on the rubber elastic body also for such a cylinder vibration damping device. In the case of a deformed anti-vibration device, the tensile stress can be removed by performing tube expansion in the direction of expanding the inner cylinder fitting, but it is difficult to uniformly perform tube expansion of the inner cylinder fitting. Attachment was not performed properly, and a cylindrical vibration isolator having stable performance could not be obtained.
[0004]
For example, as shown in FIG. 7, as an irregular cylindrical vibration isolator, a rectangular tube-shaped inner tube fitting 1 having a substantially rectangular cross section and an arc shape at four corners, and a substantially constant circumference around the inner tube fitting. It is conceivable that the outer cylinder fitting 2 having an oval cross section at right angles with a gap is provided, and the rubber elastic body 3 is integrally vulcanized and bonded to the gap between the inner cylinder fitting 1 and the outer cylinder fitting 2. When the inner cylinder fitting 1 is subjected to tube expansion processing, the arcuate portions 1a at the four corners are difficult to deform and cannot be expanded, so that the cross section perpendicular to the axis cannot be formed into a desired rectangle.
[0005]
On the other hand, as shown in FIG. 8, there are ones in which the four corners of the inner cylindrical metal fitting 4 are arc-shaped portions 4 c bulging from both the long wall portion 4 a and the short wall portion 4 b. The inner tubular metal fitting 4 can be expanded by expanding both the long wall portion 4a and the short wall portion 4b, but the dimensional variation between the long wall portion 4a and the short wall portion 4b increases. There is a problem that it is difficult to form the arcuate portions 4c at the four corners of the tubular fitting 4.
[0006]
The present inventor has found a tube expansion method capable of forming the inner cylinder fitting into a substantially rectangular cross section with respect to the irregular cylindrical vibration isolator as described above, and can manufacture a cylindrical vibration isolator having stable performance. I made it.
That is, the present invention is intended to solve the above-described problem, and an object of the present invention is to provide a cylindrical vibration isolator that does not cause irregular deformation due to tube expansion processing of the inner cylinder fitting.
[0007]
[Means for Solving the Problems and Effects of the Invention]
In order to achieve the above object, the structural feature of the invention according to claim 1 is that an inner cylindrical metal fitting having a rectangular cross section perpendicular to the axis having a pair of opposed long wall portions and a pair of opposed short wall portions, A long axis perpendicular to the cross section, which is concentrically arranged on the outside of the cylindrical fitting and has a pair of opposing parallel wall portions extending in parallel with the long wall portion and a semi-arc-shaped wall portion connecting both ends of the pair of parallel wall portions, respectively. A cylindrical vibration isolator comprising a circular outer cylinder fitting and a rubber elastic body integrally vulcanized and bonded between the inner and outer cylinder fittings, wherein the inner cylinder fitting is attached after the rubber elastic body is vulcanized and bonded. The opposing distance between the long wall portions is controlled while the opposing distance between the short wall portions is regulated to be smaller than the opposing distance between a pair of arcuate portions adjacent to each other with the short wall portion interposed therebetween. cross section perpendicular to the shaft by expanding the distance are those is rectangular, rubber elasticity for connecting the at least long wall portion and the parallel wall portion Lies in the addition of preliminary compression on.
[0008]
By configuring the invention according to claim 1 as described above, the rubber elastic body is compressed by the pipe expansion process of the inner cylinder fitting, and the tensile stress due to the rubber elastic body after vulcanization molding can be removed. It is possible to prevent a decrease in durability. And, since the tube expansion process regulates the facing distance between the short wall portions, the facing distance between the long wall portions is expanded from a size smaller than the facing distance of the arcuate portion of the four corners, so the facing distance between the long wall portions As the diameter increases, the arc diameter part can also be deformed, and the shape of the cross section perpendicular to the axis of the inner cylinder fitting is formed into a substantially rectangular desired shape.
As a result, according to the first aspect of the present invention, it is possible to obtain a cylindrical vibration isolator having stable performance while the mating member is properly attached to the inner cylindrical fitting.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIGS. 1 to 3 and FIGS. 4 to 6 show an irregularly shaped cylinder having an oval cross section in the axial direction according to the embodiment. FIG. 3 is a plan view, a cross-sectional view, and a bottom view, respectively, of the inner cylinder fitting of the mold vibration isolator before and after the pipe expansion process.
[0010]
As shown in FIG. 1 to FIG. 3, the cylindrical vibration isolator 10 has a substantially constant gap around the inner cylindrical bracket 11 and the rectangular inner cylindrical bracket 11 before the inner cylinder fitting 11 is expanded. The outer cylinder fitting 12 having an oval cross section is provided, and a rubber elastic body 13 is integrated with the inner cylinder fitting 11 and the outer cylinder fitting 12 in the gap between the inner cylinder fitting 11 and the outer cylinder fitting 12. Vulcanized and bonded.
[0011]
The inner cylinder fitting 11 is provided with a pair of opposing long wall portions 11a and a pair of opposing short wall portions 11b, and the four corners are arc-shaped portions 11c having a substantially arc-shaped cross section at right angles to the axis. The arc-shaped portion 11c bulges outward at both end sides of the long wall portion 11a. That is, the facing distance between the long wall portions 11a is smaller than the facing distance between the arcuate portions 11c at the four corners.
[0012]
The outer cylinder fitting 12 has a parallel wall portion 12a corresponding to a position between both ends of the pair of long wall portions 11a of the inner cylinder fitting 11, and a substantially arc-shaped cross section on the outside between both ends of the parallel wall portion 12a. A semicircular arc-shaped wall portion 12b is provided. The outer cylinder fitting 12 is formed with a flange portion 12c that is spread outward on one end side, and the vicinity of the other end side is an inclined portion 12d that is reduced in an axial direction toward the other end. ing. As shown in FIG. 3, in the inclined portion 12d, the parallel wall portion 12a is made smaller than the semicircular arc-shaped wall portion 12b.
[0013]
The rubber elastic body 13 is vulcanized and bonded between a pair of opposed long wall portions 11 a of the inner cylinder fitting 11 and the parallel wall portion 12 a of the outer cylinder fitting 12. Further, a rubber elastic body stopper portion 14, which is a part of the rubber elastic body 13, is provided on the semicircular arc-shaped wall portion 12 b of the outer cylinder fitting 12 with a gap between the inner wall fitting 11 and the short wall portion 11 b. It is vulcanized and bonded.
[0014]
The tube expansion processing of the inner cylinder fitting 11 is performed by passing a tube expansion jig (not shown) corresponding to the final shape of the inner cylinder fitting 11 through the inner cylinder fitting 11, and the facing distance between the short wall portions 11b is regulated. In this state, the facing distance between the long wall portions 11a is expanded while maintaining a parallel state, and the arc diameter portion 11c can be deformed as the facing distance between the long wall portions is increased. Therefore, as shown in FIGS. 4 to 6, the inner cylindrical metal member 11 is formed into a desired shape having a substantially rectangular cross section by the tube expansion process, and the rubber elastic body 13 is compressed. Thus, the tensile stress due to the rubber elastic body 13 after vulcanization molding can be removed, and the durability of the cylindrical vibration isolator 10 can be prevented from being lowered.
As a result, according to the above-described embodiment, the counterpart member can be properly attached to the inner cylindrical metal fitting 11, and the cylindrical vibration isolator 10 having stable performance can be obtained.
[Brief description of the drawings]
FIG. 1 is a plan view showing a state before tube expansion processing of an inner tube metal fitting of a cylindrical vibration isolator according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the cylindrical vibration isolator taken along line II-II shown in FIG.
FIG. 3 is a bottom view of the cylindrical vibration isolator.
FIG. 4 is a plan view showing a state after tube expansion processing of the inner cylinder fitting of the cylindrical vibration isolator.
5 is a sectional view of the cylindrical vibration isolator taken along the line VV shown in FIG. 4;
FIG. 6 is a bottom view of the cylindrical vibration isolator.
7A and 7B are a plan view and a cross-sectional view in the MM line direction showing a conventional cylindrical vibration isolator.
FIGS. 8A and 8B are a plan view and a cross-sectional view in the NN line direction showing a cylindrical vibration isolator as a comparative example. FIGS.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Cylindrical vibration isolator, 11 ... Inner cylinder metal fitting, 11a ... Long wall part, 11b ... Short wall part, 11c ... Arc shape part, 12 ... Outer cylinder metal fitting, 12a ... Parallel wall part, 12b ... Semi-arc shape wall Part, 12c ... collar part, 12d ... inclined part, 13 ... rubber elastic body, 14 ... rubber elastic body stopper part.

Claims (1)

And the inner sleeve cross section perpendicular to the shaft rectangular with a circular arc shape portion of the pair of short wall portions and four corners facing the pair of long wall portions facing, disposed concentrically on the outside of the inner tubular member, said long wall An outer cylinder fitting having an oval cross section perpendicular to the axis and having a pair of parallel wall portions extending in parallel with each other and a semi-arc-shaped wall portion connecting both ends of the pair of parallel wall portions, and the inner cylinder A cylindrical vibration isolator provided with a rubber elastic body integrally vulcanized and bonded between a metal fitting and an outer cylinder metal fitting,
The inner cylinder fitting is configured so that the opposing distance between the long wall portions of the opposing distances between the short wall portions and the long wall portions is opposed to a pair of arcuate portions adjacent to each other with the short wall portion interposed therebetween. It is formed in a dimension smaller than the distance, and after the rubber elastic body is vulcanized and bonded, the opposing distance between the short wall portions is regulated while the opposing distance between the long wall portions is expanded, and the cross section perpendicular to the axis is the rectangle. A cylindrical vibration isolator characterized in that preliminary compression is applied to at least the rubber elastic body connecting the long wall portion and the parallel wall portion.

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