JP2000035071A - Rubber bush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the structure by the reduction in the number of parts and to improve the productivity and assembling workability. SOLUTION: A rubber elastic body 14 is arranged in the outer circumferential face of a shaft metal 12 and the axial both ends of the rubber elastic body 14 are formed into a first and a second wall-thickness part 28, 30 with their diameters set larger than that of the center part 26. The second wall-thickness part 30 is projected outward in the axial direction than the axial metal 12 and a through hole 44 extended along the outer circumferential face of the shaft metal 12 is formed in the internal circumference of the second wall- thickness part 30. After the rubber elastic body 14 is internally inserted from the second wall-thickness part 30 side to the outer cylinder member 16, an annular metal 48 is inserted in the through hole 44 to be press fixed in the shaft metal 12 so that a second flange part 48 is formed, and at the same time the second wall-thickness part 30 is axially compressed by the annular metal 48 (second flange part) and so the first and the second wall-thickness parts 28, 30 are arranged in press contact between the axial both ends 54, 58 of the outer cylinder member 16 and the axial opposite faces of the first and the second flange parts 18, 48.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber bush that elastically connects a shaft fitting to an outer cylindrical member externally arranged in the same in a radial direction and an axial direction. The present invention relates to a rubber bush that can be suitably used.

[0002]

2. Description of the Related Art Conventionally, as one type of a vibration isolating connection device interposed between members constituting a vibration transmission system, a shaft fitting and an outer cylinder member which are arranged radially apart from each other are interposed therebetween. A rubber bush that is elastically connected in a radial direction and an axial direction by a rubber elastic body is known. For example, a suspension bush interposed in a pivotal connection portion between a suspension rod of an automobile and a wheel side or a vehicle body side is known. And so on.

In a conventional rubber bush, for example, as shown in FIG.
The rubber elastic body disposed between the two members is constituted by two divided rubber elastic bodies 5 and 6 divided on both sides in the axial direction. A structure was adopted in which both sides were fitted and assembled. In such a rubber bush, each of the divided rubber elastic bodies 5 and 6 has a radial connecting portion 7 interposed between radially opposed surfaces of the shaft fitting 2 and the outer cylindrical member 3, and a shaft of the shaft fitting 2. An axial connecting portion 9 interposed between axially opposed surfaces of a flange portion 8 fixed to both ends in the direction and an axial end surface of the outer cylindrical member 3;
Each of the pair of radial connecting portions 7, 7 and the axial connecting portion 9,
9, the shaft fitting 2 and the outer cylinder member 3 are elastically connected in the radial direction and the axial direction.

However, in the rubber bush having such a conventional structure, the two divided rubber elastic bodies 5 and 6 must be separately vulcanized and then assembled between the shaft fitting 2 and the outer cylindrical member 3. Therefore, manufacturing and installation were very troublesome. In particular, in order to attain a high spring characteristic required for the rubber bush, it may be necessary to form slits 10 and 11 having different shapes from each other in the two split rubber elastic bodies 5 and 6. It is also difficult to use a common vulcanization mold for each of the divided rubber elastic bodies 5 and 6, so that there is a problem that the production cost is high.

[0005]

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a shaft fitting and an outer cylinder formed of a single rubber elastic body. It is an object of the present invention to provide a rubber bush which is capable of elastically connecting members in a radial direction and an axial direction and has excellent manufacturability and mountability.

[0006]

In order to solve such a problem, a feature of the present invention is to provide a shaft bracket having first and second flange portions that extend radially outward at both axial ends. A cylindrical rubber elastic body disposed on the outer peripheral surface of the shaft fitting, and the shaft fitting is inserted through an outer cylindrical member having a smaller axial length than the shaft fitting. Thus, between the radially opposed surfaces of the outer peripheral surface of the shaft fitting and the inner peripheral surface of the outer cylinder member, and the axes of the first and second flange portions of the shaft fitting and both axial end surfaces of the outer cylinder member. In the rubber bush elastically connected by the rubber elastic body between the opposing surfaces, the first flange portion is fixed to one end in the axial direction of the shaft fitting, and the outer periphery of the shaft fitting is fixed. The rubber elastic body is disposed on the surface, and both ends of the rubber elastic body in the axial direction are centered in the axial direction. The first and second thick portions are formed as larger diameters, and the first thick portion is arranged on the first flange portion side, while the second thick portion is larger than the shaft fitting. Along with projecting outward in the axial direction, a cylindrical hollow hole extending axially inward from the axial end of the second thick portion side and extending along the outer peripheral surface of the shaft fitting is formed, The second flange portion is formed by externally fitting and fixing a separate annular metal fitting having a cylindrical fitting portion inserted into the lightening hole to the shaft fitting at the cylindrical fitting portion. By compressing and deforming the second thick portion in the axial direction at the second flange portion, the axial end portions of the outer cylindrical member and the first flange portion and the second flange portion are formed. The first thick portion and the second thick portion of the rubber elastic body are brought into pressure contact with the axially opposed surface.

In the rubber bush having the structure according to the present invention, the rubber elastic body for elastically connecting the shaft fitting and the outer cylindrical member in the radial direction and the axial direction is formed with a single structure. In a second thick portion formed at one end in the axial direction of the rubber elastic body, a lightening hole extending in the axial direction along the outer peripheral surface of the shaft fitting is formed, and the second thick portion is formed. Since the portion is easily elastically deformable in the diameter reducing direction, for example, when the shaft fitting is inserted into the outer cylindrical member, the rubber elastic body is simultaneously removed from the second thick portion side. It is possible to dispose it by inserting it into the tubular member. Further, after disposing the rubber elastic body between the shaft fitting and the outer cylindrical member in this manner, the cylindrical fitting portion of the annular fitting is fitted and fixed to the shaft fitting to form the second flange portion. Thereby, for the first and second thick portions of the rubber elastic body, the effective axial direction is provided between the axial both end surfaces of the outer cylindrical member and the first and second flange portions of the shaft fitting. Since a compressive force can be exerted, the shaft elastic member and the outer cylindrical metal member are advantageously elastically connected in the radial direction and the axial direction by the rubber elastic body.

Therefore, in the rubber bush according to the present invention, a rubber elastic body for elastically connecting the shaft bracket and the outer cylinder member is provided.
Since it can be formed as a single molded product using a single mold, the productivity is dramatically improved compared to a conventional rubber bush that requires a rubber elastic body with a two-part structure. obtain. In addition, in the rubber bush according to the present invention, compared to the rubber bush that requires a rubber elastic body having a conventional two-part structure, the number of components is small, so that excellent mounting workability is exhibited. In particular, since the elastic thinning deformation of the second thick portion is easily allowed by the lightening hole, extremely excellent work is performed when assembling the rubber elastic body to the outer cylinder member. Sex can be exhibited.

In the present invention, the shaft fitting and the outer cylindrical member may be fixedly attached to each of the members to be vibration-isolated, and the specific structure is not limited. . Specifically, as the shaft fitting, for example, a solid rod-shaped fitting, a hollow cylindrical fitting, or the like can be adopted,
Further, as the outer cylindrical member, for example, a cylindrical metal fitting provided with a bracket, an arm eye integrally formed with a rod, or the like can be adopted. The first flange portion may be formed by fixing another member to the shaft fitting by welding, bolting, or the like, or may be formed integrally with an end portion of the shaft fitting by press working or the like. Furthermore, the rubber elastic body may be disposed in a non-adhesive state with respect to the shaft fitting, but is desirably adhered to the shaft fitting, and in this case, the rubber elastic body is bonded to the shaft fitting after vulcanization molding. Although it is also possible, such a rubber elastic body is preferably formed of an integrally vulcanized molded product which is vulcanized and bonded to a shaft fitting at the same time as its molding. In addition, the first thick portion of the rubber elastic body is formed to have a free length in the axial direction that is larger than the distance between the outer cylinder member and the first flange portion in the axial direction when the rubber bush is mounted. And it is desirable to be fixed to the first flange portion by vulcanization bonding or the like. On the other hand, the second thick portion of the rubber elastic body is also formed with a free length in the axial direction that is larger than the distance between the axially opposed surfaces of the outer cylinder member and the second flange portion under the mounted state of the rubber bush. It is desirable that the outer peripheral surface of the axial end portion be tapered to facilitate attachment to the outer cylinder member. Furthermore, the lightening hole formed in the rubber bush is
In order to make it easier to attach the rubber bush to the outer cylinder member, it is desirable to form the rubber bush at least over the entire axial length of the second thick portion.

Further, in the rubber bush having the structure according to the present invention, the rubber elastic body disposed between the radially opposed surfaces of the shaft fitting and the outer cylinder member is provided with the rubber elastic body opposed to the radially opposed shape of the shaft fitting and the outer cylinder member. Although it may be disposed in a state of being pressed against substantially the entire surface, preferably, for example, in the axial center portion of the rubber elastic body disposed between the shaft fitting and the radially opposed surface of the outer cylinder member, A small-diameter portion having a small outer diameter and a large-diameter portion having a large outer diameter are formed, and the large-diameter portion is press-fitted between the radially opposed surfaces of the shaft fitting and the outer cylindrical member. , So as to form a gap extending along the inner peripheral surface of the outer cylinder member. By adopting such a configuration, the spring characteristics of the rubber bush can be adjusted by appropriately adjusting the size and position of the large-diameter portion and the small-diameter portion. It can be aimed at.

The position and size of the large-diameter portion are not limited at all. For example, a pair of large-diameter portions are formed so as to protrude from both sides facing each other in one radial direction with a shaft fitting interposed therebetween. This makes it possible to set a large spring ratio in two radial directions orthogonal to each other. Further, for example, by forming the large-diameter portion at a part in the axial direction so as to correspond to the center of the external input torsion, the torsion spring of the rubber bush is set to be soft or the durability is improved. It is also possible.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

First, FIG. 1 shows a mounted state of a rubber bush as an embodiment of the present invention. The rubber bush includes an inner cylinder fitting 12 as a shaft fitting and a rubber elastic body 14, and is inserted and attached to an outer cylinder fitting 16 as an outer cylinder member. Thus, the inner cylindrical fitting 12 and the outer cylindrical fitting 16 are elastically connected in the radial direction and the axial direction via the rubber elastic body 14.

More specifically, the inner cylindrical member 12 has a straight cylindrical shape, and its axial length is sufficiently larger than the outer cylindrical member 16 to be inserted. A substantially annular plate-shaped first flange metal member 18 is superimposed on one end surface (right side in the drawing) of the inner cylindrical metal member 12 in the axial direction and fixed by welding or the like. Flange fitting 18
Thus, a first flange portion extending radially outward from the inner cylinder fitting 12 is formed. The first flange 1
The center hole 20 of 8 has substantially the same diameter as the inner hole 22 of the inner tube fitting 12.

On the other hand, the rubber elastic body 14 has a substantially cylindrical shape as a whole, and is arranged on the outer peripheral surface of the inner cylinder fitting 12. In particular, in the present embodiment, when the rubber elastic body 14 is molded, the inner cylindrical metal fitting 12 is provided in the molding cavity, so that as shown in FIGS. It is formed as an integral vulcanized molded product 24 that is vulcanized and adhered to 12.

Here, the rubber elastic body 14 is
Both ends in the axial direction have a larger diameter than the central portion 26 in the axial direction, and are thickened in the radial direction.
A first thick portion 28 and a second thick portion 30 are integrally formed on both sides in the axial direction. The axial end surface of the first thick portion 28 is formed on the axial inner surface 60 of the first flange fitting 18.
Vulcanized. Note that the axial length of the central portion 26, in other words, the dimension between the axially opposed surfaces of the first thick portion 28 and the second thick portion 30 is determined by the external cylinder 16 to be inserted.
Is set to be approximately the same as the length in the axial direction. Further, the outer peripheral surfaces of the first thick portion 28 and the second thick portion 30 are provided with tapered surfaces 32, 34 whose outer diameters decrease toward the distal end side in the axial direction. The outer end of the thick portion 30 in the axial direction has a smaller outer diameter than the axial end of the first thick portion 28.

The central portion 26 is partially different in thickness (outer diameter) in the radial direction, and has a small diameter portion 36 having a small outer diameter and a large diameter portion 38 having a large outer diameter. are doing. The small diameter portion 36 occupies most of the central portion 26, and the outer diameter of the small diameter portion 36 is Ra (see FIG. 2).
Is set sufficiently smaller than the inner diameter dimension R (see FIG. 1) of the outer cylindrical metal fitting 16 to be extrapolated. On the other hand, the large diameter portion 38 is located on one side in the axial direction at the central portion 26 (FIG. 2).
In the part deviated to the right (middle, right), a pair is formed so as to face each other in the radial direction. These large diameter portions 38, 38
Are approximately 1 / from the outer peripheral surface of the small diameter portion 36 in the circumferential direction.
It has a length of less than four rounds and is formed to protrude in a substantially fan-shaped manner, and both axial side surfaces are formed as a substantially mountain-shaped inclined surface with a flared skirt. The maximum outer diameter of each large diameter portion 38 is Rb.
(Refer to FIG. 2) is the inner diameter of the outer tube fitting 16 to be extrapolated:
It is set sufficiently larger than R.

In this embodiment, a recess 40 surrounding each large diameter portion 38 is formed by reducing the outer diameter of the small diameter portion 36 around each large diameter portion 38. . The concave portion 40 functions as a rubber escape portion or the like when the large diameter portion 38 is compressed and deformed in the radial direction. At both ends in the axial direction of the central portion 26, annular recesses 42, 42 extending continuously in the circumferential direction at the boundary between the first and second thick portions 28, 30 are formed. These annular recesses 42, 42 function as a relief portion for rubber when the first and second thick portions 28, 30 are compressed and deformed in the axial direction.

Further, in the rubber elastic body 14, a second thick portion 30 is projected from the axial end of the inner cylindrical fitting 12 outward in the axial direction by a predetermined length. Further, the rubber elastic body 14 is provided with a lightening hole 44 which is opened at an axial end face on the side of the second thick part 30 and extends at a predetermined length in the axial direction along the outer peripheral surface of the inner cylinder fitting 12. ing. This meat hole 44
Has a cylindrical cross-section that continuously extends over the entire circumference of the inner cylinder fitting 12, and the surface of the inner cylinder fitting 12 is substantially exposed in the lightening hole 44. In particular, in the present embodiment, the lightening hole 44 is formed with an axial length that is longer than the second thick portion 30 and does not reach the large diameter portion 38, and extends over the entire circumference in the circumferential direction. And has a substantially constant axial length and a substantially constant radial width over the entire length.

A second flange fitting 48 is fixedly attached to such an integrally vulcanized molded product 24 at an axial end of the inner tubular fitting 12 on the side of the second thick portion 30. , Whereby the intended rubber bush is provided, where before the second flange fitting 48 is attached, as shown in FIG. The outer tube fitting 16 is externally mounted.

The outer cylindrical member 16 has a thick cylindrical shape whose axial length is shorter than that of the inner cylindrical member 12, and the integrally vulcanized molded product 24 is inserted through the mounting hole 46. It is supposed to be. The insertion of the integrally vulcanized molded product 24 into the outer cylinder 16 is performed by inserting the integrally vulcanized molded product 24 into the mounting hole 46 of the outer cylinder 16 in the axial direction from the second thick portion 30 side. It is done by pushing. At this time, the maximum outer diameter dimension Rc of the second thick part 30 is larger than the inner diameter dimension R of the mounting hole 46, but due to the presence of the lightening hole 44, the diameter reduction direction of the second thick part 30 is reduced. The integrally vulcanized molded product 24 can be easily elastically deformed into
6 can be easily inserted.

The outer tube fitting 16 is extrapolated to the central portion 26 of the rubber elastic body 14 by extrapolation to the integrally vulcanized molded product 24, and the first thick portion 2 is provided on both axial sides thereof.
8 and the second thick part 30 are located. The large-diameter portions 38, 38 of the central portion 26 of the rubber elastic body 14 are pressed against the inner surface of the mounting hole 46 of the outer tube fitting 16 to be compressed and deformed, and the pair of large-diameter portions 38, 38 are formed. Thus, the inner cylinder 12 and the outer cylinder 16 are elastically connected in the radial direction, and the inner cylinder 12 and the outer cylinder 16 are elastically positioned and held substantially on the same axis. In addition,
The small diameter portion 36 in the central portion 26 of the rubber elastic body 14
The outer peripheral surface of the small-diameter portion 3 is not in contact with the outer tube fitting 16.
A buffer space 50 is formed between the outer peripheral surface of the outer tube 6 and the inner peripheral surface of the outer cylindrical member 16 so as to extend with a substantially constant gap over the whole.

After the external fitting 16 is inserted and mounted, the second flange fitting 4 assembled to the integrally vulcanized molded product 24 is formed.
As shown in FIG. 5, reference numeral 8 denotes an annular plate having substantially the same shape as the first flange fitting 18, and a fitting cylinder portion as a cylindrical fitting portion is provided on the inner peripheral edge thereof. 52 are integrally formed by press working or the like. The fitting tube portion 52 has an axial length and a wall thickness substantially the same as those of the lightening hole 44 formed in the integrally vulcanized molded product 24, and is projected from the second flange fitting 45. The dimensions are slightly smaller than the outer diameter dimension of the inner cylinder fitting 12. Then, the fitting cylinder portion 52 is inserted into the lightening hole 44, is press-fitted into the inner cylinder fitting 12 and is externally fitted and fixed, whereby the inner cylinder fitting 12 is radially outward from the axial end edge. A second flange portion protruding from the second flange fitting 48 is formed. The lightening hole 44 has been substantially eliminated by inserting the second flange fitting 48.

When the second flange metal fitting 48 is externally fitted and fixed to the axial end of the inner cylindrical metal fitting 12, the second thick portion 30 projecting from the inner cylindrical metal fitting 12 in the axial direction is formed. It is pressed inward in the axial direction by the second flange fitting 48.
As a result, both axial end surfaces of the second thick portion 30 are pressed against the axial end surface 54 of the outer cylindrical member 16 and the inner surface 56 of the second flange member 48, and the outer cylindrical member 16 and the second cylindrical member 48 are pressed against each other. It is interposed between the flange fittings 48 in a state of being compressed and deformed in the axial direction. Further, the elastic force of the second thick portion 30 is exerted on the outer cylindrical member 16, and the outer cylindrical member 16 is displaced in the axial direction.
8 and the inner surface 60 of the first flange member 18, an axial compressive force is applied to the first thick portion 28,
As a result, the first thick portion 28 is interposed between the outer cylindrical member 16 and the first flange member 18 in a state of being compressed and deformed in the axial direction. Then, based on the elastic force of the first and second thick portions 28, 30, the inner cylindrical member 12 and the outer cylindrical member 16 are relatively positioned and held elastically in the axial direction. In short, the first and second thick portions 28,
In each case 30, the free length in the axial direction is set to be larger than that in the assembled state. The first and second meat portions 28 and 30 are assembled in such a compressed and deformed state as described above, so that the axial spring rigidity between the inner cylinder 12 and the outer cylinder 16 is advantageously secured. It is to be done.

In the rubber bush having the above-described structure, although not explicitly shown in the drawings, for example, a support shaft or the like fixed to the vehicle body side or the wheel side with respect to the inner cylinder fitting 12 is provided. While being inserted and fixed with bolts and the like,
6, a suspension rod extending from the outer peripheral surface in the direction perpendicular to the axis is integrally formed. Or it will be elastically connected to the wheel side.

The central portion 26 of the rubber elastic body 14 and the first and second thick portions 2 are protected against an axial or perpendicular vibration load applied between the inner and outer cylindrical fittings 12 and 16.
8 and 30 can exhibit a vibration damping effect based on the elastic deformation, and particularly in the direction perpendicular to the axis, the large-diameter portions 38 and 38.
A large spring ratio will be exerted in the direction opposite to and the direction perpendicular thereto. Moreover, in the direction perpendicular to the axis, a non-linear load-spring characteristic is exerted by the action of the buffer space 50 formed between the central portion 26 of the rubber elastic body 14 and the outer cylinder fitting 16, so that a small load can be input. On the other hand, when a large load is input, an effective stopper-like function can be exhibited while ensuring a sufficiently soft spring characteristic. In particular, in the rubber bush of the present embodiment, the inner cylinder fitting 12
A large-diameter portion 3 protruding from a portion of the central portion 26 of the rubber elastic body 14 in the axial direction is provided between the radially opposed surfaces of the
Only at positions 8 and 38, which are directly elastically connected, the positions of the large-diameter portions 38 and 38 substantially coincide with the center of the torsion load (the torsion center) applied between the inner and outer tube fittings 12 and 16. With such a setting, a soft torsion spring characteristic can also be advantageously provided.

Further, in such a rubber bush, the rubber elastic body elastically connecting the inner and outer cylindrical fittings 12, 16 in the axial direction and the radial direction is constituted by a single rubber elastic body 14.
Since it can be easily produced by one vulcanization molding operation with one molding die, extremely excellent manufacturability can be realized. In the rubber elastic body 14, a lightening hole 44 for fixing the second flange metal member 48 to the inner cylindrical metal member 12 is formed in an inner peripheral portion of the second thick portion 30. The hollow portion 44 is used to improve the elastic deformation of the second thick portion 30 in the radial direction, so that the rubber elastic body 14 can be integrated with the outer cylindrical member 16. It can be easily inserted and assembled.
Thereby, excellent mounting workability of the rubber bush is realized.

As mentioned above, one embodiment of the present invention has been described in detail. However, this is a literal example.
By the specific description in such an embodiment,
It is not to be construed as limiting.

For example, the formation position and size of the large diameter portion 38,
The shape, number and the like are not limited to those of the above-described embodiment, but can be appropriately changed according to required spring characteristics and the like. Further, the entire central portion 26 of the rubber elastic body 14 is formed with a substantially constant outer diameter without providing the small diameter portion 36 and the large diameter portion 38, and the outer peripheral surface of the central portion 26 extends over substantially the entire surface. You may make it contact | abut on the outer cylinder fitting 16. FIG.

Further, a protrusion protruding in the radial direction is formed on a part of the outer peripheral surface of the inner cylinder fitting 12 or the rubber elastic body 1 is formed.
By embedding another member in a part of 4, for example, it is also possible to relatively adjust the spring characteristics exhibited in each radial direction.

Further, the first flange fitting 18 may be assembled to the inner cylindrical fitting 12 after vulcanization molding of the rubber elastic body 14 by a press-fitting structure similar to that of the second flange fitting 48, for example. .

Further, the specific structure of the outer cylindrical member 16 is not limited at all. For example, the axial end surfaces 54 and 58 where the first and second thick portions 28 and 30 are pressed against each other are formed by externally attaching It can also be formed by a pair of flanges or the like that extend radially outward from both ends in the axial direction of the cylindrical metal fitting 16.

In addition, in the above-described embodiment, an example in which the present invention is applied to a suspension bush for an automobile has been described. Of course, any of them can be advantageously applied to the rubber bush interposed at the connecting portion.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, the present invention can be implemented in a form in which various changes, modifications, improvements, and the like are made.
It goes without saying that all such embodiments are included in the scope of the present invention without departing from the spirit of the present invention.

[0035]

As is apparent from the above description, in the rubber bush having the structure according to the present invention, the rubber elastic member interposed between the axial fitting and the axially and radially opposed surfaces of the outer cylinder member. Is formed with a single structure,
The number of parts and the number of manufacturing and assembling steps are reduced, and excellent manufacturability and assemblability are exhibited. Also,
After the rubber elastic body is inserted through the outer cylinder member, the second thick portion protruding in the axial direction is compressed and deformed in the axial direction by the second flange portion, and is assembled. The rigidity is also advantageously secured. In addition, a lightening hole for fitting the second flange part (annular metal fitting) to the inner cylindrical metal fitting is formed in the inner peripheral portion of the second thick part. Since the elastic deformation of the thick part in the radial direction is easily allowed, the rubber bush is inserted into the outer cylindrical member in the axial direction from the second thick part side. Thereby, it can be easily assembled with good workability.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a mounted state of a rubber bush as one embodiment of the present invention, and is a view corresponding to a section taken along line II-II in FIG.

FIG. 2 is a longitudinal sectional view showing an integrally vulcanized molded product constituting the rubber bush shown in FIG. 1, and is a II-II in FIG.
It is a figure corresponding to a cross section.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a left side view in FIG. 2;

FIG. 5 is a front view showing a second flange fitting constituting the rubber bush shown in FIG. 1;

6 is a longitudinal sectional view showing a mounting state of a rubber bush having a conventional structure, and is a view corresponding to a section taken along line VI-VI in FIG.

FIG. 7 is a right side view in FIG.

[Explanation of symbols]

 12 Inner Tube Fitting 14 Rubber Elastic Body 16 Outer Tube Fitting 18 First Flange Fitting 24 Integrated Vulcanized Molded Product 26 Central Part 28 First Thick Part 30 Second Thick Part 44 Lightening Hole 48 Second Flange Metal fittings

Claims (2)

[Claims] 1. A shaft fitting having first and second flanges extending radially outward at both ends in the axial direction, and a cylindrical rubber elastic body disposed on an outer peripheral surface of the shaft fitting. The shaft fitting is inserted and arranged in an outer cylindrical member having a smaller axial length than the shaft fitting, so that the diameter of the outer peripheral surface of the shaft fitting and the inner peripheral surface of the outer cylindrical member is reduced. Rubber bush elastically connected by the rubber elastic body between the axially opposed surfaces and between the axially opposed surfaces of the first and second flange portions of the shaft fitting and the axially opposite end surfaces of the outer cylindrical member, respectively. In the above, the first flange portion is fixed to one end in the axial direction of the shaft fitting, and the rubber elastic body is disposed on the outer peripheral surface of the shaft fitting, and both ends in the axial direction of the rubber elastic body. Forming a first and second thick portion with a larger diameter than the central portion in the axial direction,
The first thick portion is disposed on the first flange portion side, while the second thick portion is projected outward in the axial direction from the shaft fitting, and the second thick portion is disposed on the second thick portion side. A cylindrical lightening hole extending inward in the axial direction from the axial end and extending along the outer peripheral surface of the shaft fitting; and a cylindrical fitting portion inserted into the lightening hole. The second flange portion is formed by externally fixing the annular fitting of the body to the shaft fitting at the cylindrical fitting portion, and the second thick portion is pivoted by the second flange portion. By compressively deforming in the direction, the first thick portion of the rubber elastic body and the axially opposed surfaces of both ends in the axial direction of the outer cylindrical member and the first flange portion and the second flange portion. A rubber bush characterized in that the second thick portion is pressed against the rubber bush. 2. A small-diameter portion having a small outer diameter and a large-diameter portion having a large outer diameter at a central portion in the axial direction of the rubber elastic body provided between the shaft fitting and a radially opposed surface of the outer cylinder member. A diameter portion is formed, and the large diameter portion is disposed in pressure contact between the shaft fittings and the radially opposed surfaces of the outer cylinder member, and at the small diameter portion along the inner peripheral surface of the outer cylinder member. The rubber bush according to claim 1, wherein a widening gap is formed.