JPH10259839A - Elastic bush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb the dimensional tolerance of a hole diameter for a support side member, and to secure the sufficient tightening margin by providing a rib extending in the direction parallel to the axis with the prescribed intervals in the circumferential direction on the outer circumferential surface of an outer cylinder, and setting the tightening margin for press-fitting into a fitting hole including the rib height. SOLUTION: An elastic bush A is interposed between an inner metallic cylinder 1 and an outer metallic cylinder 2 which are arranged with concentric intervals, and integrated with both cylinders by a rubber elastic body 3 fixed to both cylinders. Projected ribs 4 extending in the direction parallel to the axis are formed on the outer circumferential surface of the outer cylinder 2 at >=4 places with the prescribed intervals in the circumferential direction, leaving an end part 2a on the tip side in the press-fitting direction of the outer cylinder 2. The outside diameter (d) of the outer cylinder 2 is same as or slightly smaller than the diameter of a fitting hole, and the diameter of the circumscribed circle of the rib 4 is slightly larger than the hole diameter taking into consideration the tightening margin. The dimension tolerance of the hole diameter of the support side member can be absorbed thereby, and the sufficient tightening main can be secured, and surely press-fitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elastic bush used mainly in a suspension mechanism of an automobile.

[0002]

2. Description of the Related Art Conventionally, in a suspension of a vehicle such as an automobile, a connecting portion between a vehicle body and a suspension, for example, a connection between a suspension arm (a lower arm or the like) supporting wheels and a vehicle body side member. An elastic bush is used at the site for cushioning.

As shown in FIG. 8, for example, an elastic bush is provided with a metal inner cylinder (51) and an outer cylinder (5) arranged concentrically.
2) are connected by a rubber elastic body (53) interposed between the two cylinders by means of a vulcanization bonding means. Usually, the outer cylinder (52) is provided at the end of the arm (60). The connecting rod on the vehicle body side is inserted into the inner cylinder (51) for use. In some cases, a flange is provided at one end of the outer cylinder for positioning of press-fitting or the like.

[0004] When the above-mentioned elastic bush is press-fitted into a supporting member such as a suspension arm and fixed,
The interference between the two, that is, the hole diameter (D) of the mounting hole (61)
Difference (d) between the outer diameter (d) of
-D) is generally designed in consideration of about 0.05 to 0.3 mm.

However, due to the dimensional tolerance (accuracy) of the hole diameter (D) of the support-side member such as the suspension arm, the above-mentioned interference is not sufficiently obtained, and the fixing is weakened. , The buckling deformation of the outer cylinder (52) may occur, or poor press-fitting may occur due to excess capacity of the press-fitting machine.

A first object of the present invention is to provide a rib on the outer peripheral surface of an outer cylinder so that a dimensional tolerance of a hole diameter of a support side member can be absorbed, a sufficient interference can be secured, and a press-fit load can be reduced. Another object of the present invention is to provide an elastic bush that can be easily and reliably press-fitted.

Further, in the case where a flange is provided at one end of the outer cylinder, if the rib is provided on the outer peripheral surface of the outer cylinder as described above, the upper edge of the rib is scraped off at the end face of the support side member when the bush is press-fitted. As a result, the shavings may remain between the flange and the support-side member, which may cause insufficient press-fitting (defective).

Accordingly, a second object of the present invention is to provide an elastic bushing which can solve the above-mentioned problem and reliably press-fit to a predetermined position when a flange is provided at one end of the outer cylinder. It is in providing.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 is characterized in that an inner cylinder and an outer cylinder arranged concentrically are interposed between the two cylinders. An elastic bush, which is connected by a rubber elastic body, and is press-fitted into a mounting hole of a support-side member such as a suspension arm. A rib extending in a parallel direction is provided, a tightening allowance for press-fitting into the mounting hole is set including the rib height, and the dimensional tolerance of the mounting hole can be absorbed by the rib. Features.

With this elastic bush, the interference for press-fitting the support-side member such as the suspension arm into the mounting hole is set including the rib height of the outer peripheral surface of the outer cylinder. The press-fit load is reduced as compared with the case of press-fitting with the outer cylinder as it is, and the tightening margin can be increased accordingly, and the dimensional tolerance of the mounting hole can be absorbed by the rib, so that the outer cylinder buckles. Deformation does not occur or press-fitting failure does not occur, and press-fitting can be performed easily and reliably.

In particular, when the interference is set within the range of the rib height as in claim 2, a large interference can be taken and the press-fit load can be reduced, which is more preferable.

According to a third aspect of the present invention, in the above-mentioned elastic bush, a flange bent outward is provided at one end in the axial direction of the outer cylinder, and the flange is cut at a position corresponding to the rib. A notch is provided.

In the case of this elastic bush, even if the upper edge portion of the rib on the outer peripheral surface of the outer cylinder may be scraped off at the side end face of the support-side member when the support-side member is pressed into the mounting hole, the shavings are removed. Since it is discharged from the notch at the position corresponding to the rib on the flange, there is no shavings left between the side end surface of the support side member and the flange, so that the predetermined position where the flange contacts the side end surface of the support side member Press-fitting and secure.

In the elastic bush of each of the above-mentioned inventions, the ribs on the outer peripheral surface of the outer cylinder are preferably provided at four or more positions at equal angular positions in the circumferential direction as in the invention of the fourth aspect. By doing so, the balance and stability in the press-fitted state are improved.

In the above elastic bush, when the outer diameter of the outer cylinder is (d), the diameter of the circumscribed circle of the rib is (d1), and the diameter of the mounting hole for the arm or the like is (D), What is set as follows is preferable.

D−D = −1.0 to 0 mm d1−D = 0.5 to 1.5 mm That is, by setting as described above, all the interferences are set within the range of the rib height. In addition, since the interference can be larger than before, the press-fit load can be reduced,
Press-fitting can be performed easily and reliably.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing an elastic bush (A) according to a first embodiment of the present invention, FIG. 2 is a front view of the elastic bush (A), and FIG. It is sectional drawing of the press-fit state in the attachment hole (11) which a member (10) has.

In the figure, an elastic bush (A) is comprised of a metal cylindrical inner cylinder (1) and an outer cylinder (2) which are concentrically arranged at intervals and are interposed between the two cylinders. The two cylinders are integrally joined by a rubber elastic body (3) fixed to both the cylinders by vulcanization bonding means, and the inner cylinder (1) is usually formed slightly longer than the outer cylinder (2).

On the outer peripheral surface of the outer cylinder (2), at four or more places at required circumferential intervals, for example, four places at equal angular intervals as shown in FIG. A protruding rib (4) is formed leaving an end (2a) on the distal end side in the press-fitting direction of the outer cylinder (2). Then, the interference for press-fitting the support side member (10) into the mounting hole (11) is set including the height of the rib (4), and the dimensional tolerance of the mounting hole (11) is set to the rib (4). 4).

That is, the outer diameter (d) of the outer cylinder (2)
Is formed slightly smaller than the hole diameter (D) of the mounting hole (11), and the diameter (d1) of the circumscribed circle of the rib (4) is larger than the hole diameter (D) in consideration of the interference. For example, the outer diameter (d) and the diameter (d1) of the circumscribed circle of the rib, that is, the rib height are set so as to satisfy the following equation. d-D = -1.0 to 0 mm d1-D = 0.5 to 1.5 mm As a result, the interference (d1-D) for press-fitting is formed within the height range of the rib (4). In addition, since it is set to be larger than before, even if the interference is large, an excessive press-fit load is not applied at the time of press-fitting, and press-fitting can be performed relatively easily. In addition, the dimensional tolerance of the mounting hole (11) can be absorbed by the rib (4), and the press-fit can be reliably fixed. FIG.
Indicates the press-fit state.

When the difference (d-D) between the outer diameter (d) of the outer cylinder (2) and the hole diameter (D) is larger than 0 mm, the entire peripheral surface of the outer cylinder (2) has an interference. It is not preferable because the press-fitting load increases due to the press-fitting, and if the difference is smaller than −1 mm, the tightening force by the press-fitting is weak and easily unstable, which is not preferable.

Further, a rib (4) on the outer peripheral surface of the outer cylinder (2)
Are not necessarily provided at equal angular intervals in the circumferential direction,
It is particularly preferable to provide four or more equally spaced angular positions in the circumferential direction as shown in the figure, because the balance and stability in the press-fitted state are improved.

FIGS. 4 and 5 show an outer cylinder (2) connected to the inner cylinder (1) via a rubber elastic body (3) at one end thereof with a flange (5) bent outward. An example of the case is shown.

Also in this case, on the outer peripheral surface of the outer cylinder (2), ribs (4) extending in a direction parallel to the axis are provided at four or more places at required intervals in the circumferential direction, similarly to the above embodiment. And
The interference for press-fitting is set including the height of the rib (4). The outer diameter (d) of the outer cylinder (2), the hole diameter (D) of the mounting hole (11), and the rib ( 4) Diameter of the circumscribed circle (d
The relations such as 1) are set in the same manner as described above.

In this case, the flange (5) is provided with a notch (6) at a position corresponding to the rib (4) as shown in FIG. The notch (6) can be not only a groove extending from the outer peripheral end of the flange to the outer peripheral surface of the outer cylinder as shown in FIG. 5, but also an arbitrary shape capable of discharging shavings described later. The notch width is preferably at least as large as or slightly larger than the width of the rib (4).

In the case of the elastic bush (A), as shown in FIG. 6, when the elastic bush (A) is pressed into the mounting hole (11) of the support side member (10), the outer cylinder ( 2) Even if the upper edge of the rib (4) on the outer peripheral surface is cut off, the shavings (12) are discharged from the notch (6) in the flange (5), Shavings (12) between the side end surface of the supporting side member (10) and the flange (5)
Will not remain. Therefore, the flange (5) can be securely press-fitted and fixed to a predetermined position where the flange (5) comes into contact with the side end surface of the support-side member (10). FIG. 7 shows the press-fit state.

[0028]

As described above, according to the elastic bush of the present invention, by providing the rib on the outer peripheral surface of the outer cylinder, the dimensional tolerance of the hole diameter of the support side member can be absorbed and a sufficient interference can be secured. In addition, the press-fitting load can be reduced, and the press-fitting can be easily and surely performed.

When a flange is provided at one end of the outer cylinder, a notch is provided at a position corresponding to the rib on the flange, so that the upper edge portion of the rib is cut off at the time of press-fitting into the mounting hole. Even if the swarf is removed, the swarf is discharged from the notch at a position corresponding to the rib on the flange, so that no swarf remains between the side end surface of the support-side member and the flange. Press-fitting and secure.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an elastic bush according to a first embodiment of the present invention.

FIG. 2 is a front view of the elastic bush.

FIG. 3 is a cross-sectional view of a state in which a support-side member is pressed into a mounting hole.

FIG. 4 is a side view showing a half section of an elastic bush according to a second embodiment of the present invention in cross section.

FIG. 5 is a front view of the elastic bush.

FIG. 6 is a cross-sectional view when the support-side member is pressed into the mounting hole.

FIG. 7 is a cross-sectional view of the above-described fully press-fitted state.

FIG. 8 is a cross-sectional view showing one example of a conventional elastic bush and one example of a supporting side member having a mounting hole.

[Explanation of symbols]

 (1) Inner cylinder (2) Outer cylinder (3) Rubber elastic body (4) Rib (5) Flange (6) Notch

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasukuni Wakita 1-17-18 Edobori, Nishi-ku, Osaka-shi, Osaka Toyo Tire & Rubber Co., Ltd. (72) Inventor Hiroshi Ohno 1-1-17 Edobori, Nishi-ku, Osaka-shi, Osaka No. 18 Toyo Tire & Rubber Co., Ltd.

Claims (5)

[Claims] An inner cylinder and an outer cylinder arranged concentrically are connected by a rubber elastic body interposed between the two cylinders, and are press-fitted into a mounting hole of a support-side member such as a suspension arm. An elastic bush, provided on the outer peripheral surface of the outer cylinder with ribs extending in a direction parallel to the axis at required intervals in the circumferential direction, and a tightening allowance for press-fitting the mounting hole with the rib height. The elastic bush is configured so as to be able to absorb a dimensional tolerance of the mounting hole by the rib. 2. The elastic bush according to claim 1, wherein the interference is set within the range of the rib height. 3. An outer cylinder is provided with a flange bent outward at one end in the axial direction, and a notch is provided at a position corresponding to the rib of the flange. Item 3. The elastic bush according to item 1 or 2. 4. The elastic bush according to claim 1, wherein ribs on the outer peripheral surface of the outer cylinder are provided at four or more locations at equal angular positions in the circumferential direction. 5. When the outer diameter of the outer cylinder is (d), the diameter of the circumscribed circle of the rib is (d1), and the diameter of the mounting hole is (D),
The elastic bush according to any one of claims 1 to 4, wherein the elastic bush is set as follows. d-D = -1.0-0 mm d1-D = 0.5-1.5 mm