JPH0996327A - Outer cylinder press-in type bush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance manufacture and assembling ability for the outer cylinder press-in type bush to be used for a vehicle. SOLUTION: In an outer cylinder press-in type bush made up of an outer cylinder 6, a cylindrical rubber 8, and of an inner cylinder 4 for a chassis to be connected with an arm, a groove 9 provided with a step part 9a faced to the axial direction is formed at the end part of the outer cylinder, and a bent part 10 to be engaged with the step part 9a is provided for the end part of the outer cylinder. Since there exists the groove 9 in the inner cylinder 4 even if there exists a thickness engraved part in the cylindrical rubber 8, the positioning of the outer cylinder 6 can be simply performed at the time of press-in. Even if external force is applied in the twisting direction, the bent part acts as a stopper against the groove 9, therefore, the outer cylinder 6 is prevented from being relatively rotated with respect to the inner cylinder 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile chassis, a member or an engine body, an arm, a rod,
The present invention relates to an outer cylinder press-fitting bush in which a bracket or the like is connected to a connecting portion while retaining elasticity.

[0002]

2. Description of the Related Art Among parts constituting an automobile, a cylindrical bush is used for a shock absorber mounting portion and a suspension arm mounting portion.
(See Japanese Utility Model Publication No. Sho 56-71407). Several types of bushes are also listed in Japanese Utility Model Laid-Open No. Sho 63-188350. A tubular rubber is housed inside a steel outer cylinder, and a steel inner cylinder is attached inside the tubular rubber. What is used is being used.

The cylindrical bush used is a combination of the above-mentioned outer cylinder, cylindrical rubber, and inner cylinder, but the inner and outer cylinders are made of vulcanized rubber. In the case of being connected, the inner cylinder and the outer cylinder are fixed to the connecting portions of the members and arms, respectively. As a result, when a moment is applied to the inner and outer cylinders in the twisting (axial rotation) direction, the tubular rubber is twisted in the circumferential direction of the bush.

Further, when only the inner cylinder is joined to the tubular rubber by vulcanization molding, when the inner cylinder is attached to the member,
A cylindrical portion corresponding to the outer cylinder is provided on the corresponding rod or the like, and the cylindrical rubber is press-fitted into the cylindrical portion. When an external force is applied to this press-fitting type in the twisting direction, the relative movement between the cylindrical portion and the inner cylinder is blocked by the friction between the tubular rubber and the cylindrical portion during press-fitting, and the tubular rubber is twisted.

As shown in FIG. 8, the press-fitting type bush is assembled by a stud bolt 2 fixed to the chassis 1.
Insert the inner cylinder 4 of the bush 3 into the and tighten it with the nut 5. The outer cylinder 6 is fixed to a rod or the like. Further, when tightening with the nut 5, a washer 7 larger than the diameter of the outer cylinder 6 is interposed so as to reduce the axial displacement of the outer cylinder 6. In the bush 3 shown in FIG. 9, flanges 8a are formed at both ends of the tubular rubber 8 so as not to shift in the axial direction.

[0006]

However, since the outer cylinder press-fitting type bush described above only obtains the damper action (damping action) in the rotational direction by the friction at the time of press-fitting, the variation of the friction at press-fitting is eliminated. To do so requires skill. In addition, since the bush 3 having a shape such as a glue (thin meat) has directionality, the damper action expected to be integrated by mistake when press-fitting does not occur. Yields.

An object of the present invention is to provide an outer cylinder press-fitting type bush which is easy to manufacture and assemble.

[0008]

In order to achieve the above-mentioned object, the present invention comprises an outer cylinder, a cylindrical rubber and an inner cylinder so as to connect a vehicle chassis, a member and the like to an arm, a rod and the like. In the cylinder press-fitting type bush, a groove having a step portion facing the axial direction is formed at an inner cylinder end portion, and a bent portion engaging with the step portion is provided at an outer cylinder end portion.

In the above outer cylinder press-fitting type bush, the opening end of the groove formed in the inner cylinder end is narrower than the engaging portion.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The cylindrical bush according to the present invention is one in which the outer cylinder and the inner cylinder are fixed to one of the corresponding arm ends and the chassis. When tightening with a nut smaller than the diameter of the cylinder, fix the stepped side of the inner cylinder that engages the bent portion of the outer cylinder to the chassis side. As a result, the bent portion serves as an axial stopper, restricts axial displacement of the outer cylinder, and a washer is not used to prevent the outer cylinder from coming off. Further, since the bent portion of the outer cylinder is engaged with the groove of the inner cylinder, relative rotation due to an external force is prevented. Furthermore, since the bent portion is aligned with the groove, the directionality at the time of press fitting is determined, and even if the tubular rubber has a curled shape, the alignment is easy.

Further, in the groove of the inner cylinder, by making the opening end smaller than the step portion side, the end surface of the inner cylinder can be made large, and the chassis and the inner cylinder can be firmly assembled.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the cylindrical bush 3 shown in FIG. 1, only the steel inner cylinder 4 is bonded to the cylindrical rubber 8 by vulcanization molding (see FIG. 3), and the steel outer cylinder 6 (see FIG. 2) is provided outside the cylindrical rubber 8. ) Is press-fitted. The outer cylinder 6 is provided with a bent portion 10 at its end that reaches the groove 9 formed in the inner cylinder 4. The bent line of the bent portion 10 is formed orthogonal to the axial direction,
The surfaces of the bent portions 10 are opposed to each other in the axial direction.

The inner cylinder 4 is manufactured by roll forming and has a groove 9 which is open at the end and extends along the axial direction. The base portion on the side opposite to the opening is notched in the circumferential direction and has a step portion facing the axial direction. 9a is formed. Thus, when the outer cylinder 6 and the inner cylinder 4 are assembled, the stepped portion 9a serves as a stopper in the press-fitting direction and the groove side surface 9b serves as a stopper in the rotational direction with respect to the bent portion 10.

As shown in FIG. 1, when the inner cylinder 4 is attached to the chassis 1 and the suspension arm (not shown) is attached to the outer cylinder 6, the inner cylinder 4 is inserted into the groove 9 in the stud bolt 2 that is erected on the chassis 1. Insert from the side and tighten the inner cylinder 4 with the nut 5. The movement of the outer cylinder 6 in the axial direction is regulated by the stepped portion 9a, and even if the friction of the outer cylinder 6 becomes loose, the outer cylinder 6 does not fall off, and a washer for preventing slipping out is not required as compared with the conventional product. Further, since the twisting direction is regulated, relative rotation between the outer cylinder 6 and the inner cylinder 4 is prevented.

Further, the width A of the bent portion 10 is equal to the width B of the stepped portion 9a.
By making it smaller, the regulation in the twisting direction is relaxed,
The angle of the stopper in the twist direction (position of the groove side surface) can be adjusted.

Further, as shown in FIG. 4, in the case where the tubular rubber 8 is formed with a meat thin portion 8a and has a cursed shape,
In the past, it was necessary to press fit while checking the direction of the suspension arm so as not to cause positional displacement in the circumferential direction, but since the directionality is determined by the bent part 10 and the groove 9, alignment is easy and press fit. Work becomes easy.

In the structure of the bent portion 10 and the groove 9, only the inlet 9c (open end) of the groove 9 is narrowed when the rotational direction and the positioning are desired to be more accurate. In this case, since the contact area between the inner cylinder 4 and the chassis 1 increases, the assembly becomes firm. In this shape, the mouth may be chamfered so that the bent portion 10 can be easily inserted. As shown in FIG. 5, the bent portion 10 can be formed such that a fold line extends along the axial direction, and the thickness of the outer cylinder 6 can be used as the width. Further, by increasing the width B on the step side of the groove 9, the stopper precision of twist is improved.

[0018]

Since the present invention is configured as described above, the engagement between the bent portion and the step portion of the outer cylinder and the inner cylinder is
When the external force of relative twist is generated, it works as a stopper, and the effect of the bush is improved. For this reason, it is possible to reduce variations in the accuracy of the bush without requiring skill. Further, in the conventional product, a washer for preventing fall is attached at the time of mounting, but the outer cylinder can be prevented from coming off without the washer, which reduces the number of parts and improves workability. Further, even in the case of a curled bush, since the groove is formed in the inner cylinder, positioning at the time of press fitting is easy.

[Brief description of drawings]

FIG. 1 is a cross-sectional view taken along the axial direction of an outer cylinder of an outer cylinder press-fitting type bush according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an outer cylinder of the bush shown in FIG.

3 is a perspective view showing an inner cylinder with a cylindrical rubber of the bush shown in FIG. 1. FIG.

FIG. 4 is a cross-sectional view of the bush shown in FIG. 1 in which a thickened portion is formed.

5 is a cross-sectional view of the bush shown in FIG. 1, showing a modified example of the bent portion.

6 is a cross-sectional view of the bush shown in FIG. 1, showing a modified example of the inner cylinder.

FIG. 7 is a top view of the inner cylinder shown in FIG.

FIG. 8 is a cross-sectional view of a conventional bush.

FIG. 9 is a cross-sectional view showing a modified example of a conventional bush.

[Explanation of symbols]

 1 Chassis 3 Bushing 4 Inner Cylinder 6 Outer Cylinder 8 Cylindrical Rubber 9 Groove 9a Step 10 Bent

Claims (2)

[Claims] 1. An outer cylinder press-fitting type bush formed of an outer cylinder, a cylindrical rubber and an inner cylinder so as to axially face an inner cylinder end portion so as to connect a vehicle chassis, a member and the like to an arm, a rod and the like. An outer cylinder press-fitting bush characterized in that a groove having a step is formed, and a bent portion that engages with the step is provided at an end of the outer cylinder. 2. The outer cylinder press-fitting type bush according to claim 1, wherein the opening end of the groove formed in the inner cylinder end is narrower than the engaging portion.