JP5910863B2 - Sliding bush - Google Patents

Description

  The present invention relates to a sliding bush used for a vehicle suspension or the like.

  A bush having a structure in which a cylindrical elastic body having rubber-like elasticity is integrally vulcanized and formed between an inner cylinder and an outer cylinder is used as a vibration reducing means at a connection portion such as a suspension arm of a vehicle. However, it is known that a bush provided with a sliding structure, that is, a sliding bush, is used to prevent breakage due to excessive deformation of the elastic body at a place where the input in the twisting direction is severe.

  As shown in FIG. 7, in a conventional sliding bush, a bush body 100 has an inner sleeve 101 and an outer sleeve 102 that is concentrically disposed on the outer peripheral side of the inner sleeve 101 and attached to one member (not shown). And a cylindrical elastic body 103 having rubber-like elasticity integrally vulcanized between the inner sleeve 101 and the outer sleeve 102, and is slidably inserted into the inner periphery of the inner sleeve 101. Some have an inner peripheral mounting cylinder 104 attached to the other member (not shown), and grease is interposed between the sliding surfaces of the inner sleeve 101 and the inner peripheral mounting cylinder 104 or a solid lubricant is provided. The inner sleeve 101 is elastically sandwiched from both sides in the axial direction via a retainer 107 by an elastic body 106 backed up by a flange 104a or a collar 105 provided on the inner peripheral side mounting cylinder 104. Directional displacement is regulated.

  That is, this sliding bush absorbs the input of radial displacement due to impact or the like by elastic deformation of the elastic body 103, and absorbs the displacement input in the torsional direction by sliding between the inner sleeve 101 and the inner peripheral mounting cylinder 104. (For example, refer to the following patent document).

Japanese Patent Laid-Open No. 11-125291

  However, such a sliding bush has many components for restricting axial displacement, and can slide only in the torsional direction, and its sliding property is not sufficient.

  The present invention has been made in view of the above points, and its technical problem is to improve the slidability in the torsional direction and also to allow sliding in the twisting direction, thus simplifying the structure. To provide a sliding bush.

As a means for effectively solving the technical problem described above, a sliding bush according to the invention of claim 1 includes a bushing body and a bush receiving sleeve disposed on an inner periphery of the bushing body. An outer sleeve, an inner sleeve that is disposed on the inner peripheral side of the outer sleeve, and has a curved convex surface having the smallest diameter in the axially intermediate portion on the inner peripheral surface, and the outer sleeve and the inner sleeve integrated with each other The bush receiving sleeve is made of a deformable synthetic resin material and is slidable in the circumferential direction with the curved convex surface of the inner sleeve on the outer peripheral surface. fitted the curved concave is formed, the bushing receiving concave curved surface of the outer peripheral surface of the sleeve, the curvature half than curved convex surface of the inner peripheral surface of the inner sleeve It is characterized in that large.

According to the configuration of the first aspect, the input of the radial displacement due to the impact or the like is absorbed by the deformation of the elastic body in the bush body, and the displacement input in the torsional direction is absorbed by the circumferential sliding of the inner sleeve and the bush receiving sleeve. Is. The bush body is twisted with respect to the bush receiving sleeve (circumferential direction) by fitting the curved convex surface formed on the inner peripheral surface of the inner sleeve to the curved concave surface formed on the outer peripheral surface of the bush receiving sleeve. ), The relative displacement in the axial direction is restricted, and the bush receiving sleeve is made of a deformable synthetic resin material. The curved concave surface has a larger radius of curvature than the curved convex surface. The sleeve can be relatively displaced in the twisting direction.

The sliding bush according to the invention of claim 2 is characterized in that, in the structure described in claim 1 , a dust seal made of a rubber-like elastic material is interposed between both end portions of the inner sleeve and the bush receiving sleeve. It is.

According to the configuration of the second aspect , it is possible to prevent external dust from intervening in the sliding portions of the inner sleeve and the bush receiving sleeve by the dust seal, and it is possible to maintain good slidability. Further, the dust seal also functions as a rubber spring between the inner sleeve and the bush receiving sleeve when inputting the twist displacement.

  According to the sliding bush according to the present invention, it is possible to improve the slidability in the torsional direction and to displace in the twisting direction with a simple structure.

It is sectional drawing which shows the bush main body in preferable embodiment of the sliding bush which concerns on this invention. It is sectional drawing which shows the bush receiving sleeve in preferable embodiment of the sliding bush which concerns on this invention. It is sectional drawing which shows an example of the assembly state in preferable embodiment of the sliding bush which concerns on this invention. FIG. 4 is a cross-sectional view showing a state in which a pick is input from the mounted state of FIG. 3. It is sectional drawing which shows the 2nd example of the assembly state in preferable embodiment of the sliding bush which concerns on this invention. It is sectional drawing which shows the 3rd example of the assembly state in preferable embodiment of the sliding bush which concerns on this invention. It is sectional drawing which shows an example of the conventional sliding bush.

  Hereinafter, the sliding bush according to the present invention will be described with reference to the drawings. First, FIG. 1 is a sectional view showing a bush body in a preferred embodiment of a sliding bush according to the present invention, FIG. 2 is a sectional view showing a bush receiving sleeve, FIG. 3 is a sectional view showing an example of an assembled state, and FIG. It is sectional drawing which shows the state into which the twist was input.

  As shown in FIG. 3, the sliding bush includes a bush main body 1, a bush receiving sleeve 2 disposed on the inner periphery of the bush main body, and a mounting sleeve 3 fitted on the inner periphery of the bush receiving sleeve 2. And a pair of O-rings 4 as a dust seal.

  As shown also in FIG. 1, the bush main body 1 has an outer sleeve 11, an inner sleeve 12 disposed on the inner peripheral side of the outer sleeve 11, and a rubber-like elastic between the outer sleeve 11 and the inner sleeve 12. It consists of a cylindrical elastic body 13 which is integrally vulcanized with a material (rubber material or synthetic resin material having rubber-like elasticity).

  The outer sleeve 11 and the inner sleeve 12 in the bush body 1 are formed of a synthetic resin material such as polyamide, preferably nylon 66 containing graphite as a solid lubricant. Among these, the outer sleeve 11 is formed in a cylindrical shape, and the inner sleeve. 12 is formed in the shape of a drawn cylinder having a curved convex surface 12a whose inner peripheral surface has the smallest diameter in the axially intermediate portion. That is, the cross section obtained by cutting the curved convex surface 12a along a plane passing through the axial center has a gentle arc shape. Further, both end surfaces 12b of the inner sleeve 12 are formed so as to form conical surfaces such that the outer diameter side projects outward in the axial direction.

  As described above, the inner sleeve 12 has a narrowed cylindrical shape and has a special shape in which both end faces 12b form a conical surface. However, since the inner sleeve 12 is a molded body made of a synthetic resin material, it can be produced at low cost.

  As shown in FIG. 2, the bush receiving sleeve 2 includes a pair of sleeve halves 2A and 2B having the same shape and the same size, and each sleeve half 2A and 2B includes a sleeve body. The sleeve 21 includes an end portion 21 and a flange portion 22 that opens from the one end portion to the outer diameter side. The sleeve body portion 21 is assembled in a state in which the end portions 21a opposite to the flange portion 22 are in contact with each other.

  On the outer peripheral surface of the bush receiving sleeve 2, more specifically, on the outer peripheral surface of the sleeve main body 21 in the sleeve halves 2A and 2B, curved concave surfaces 21b are formed across both sides of the end portion 21a. The curved concave surface 21b is fitted to the curved convex surface 12a which is the inner peripheral surface of the inner sleeve 12 in the bush body 1 so as to be slidable in the circumferential direction, and is the most on the outer periphery of the end portion 21a of the sleeve main body portion 21. A cross section formed by a plane that passes through the axial center has a gentle arc shape, and the curvature radius r2 of the curved concave surface 21b is larger than the curvature radius r1 of the curved convex surface 12a. .

  The mounting sleeve 3 is composed of a pair of sleeve halves 3A and 3B made of metal, and each of the sleeve halves 3A and 3B is formed of the sleeve body 21 in the sleeve halves 2A and 2B of the bush receiving sleeve 2. The sleeve body 31 includes a sleeve main body 31 that can be press-fitted into the inner periphery, and a flange 32 that opens from one end to the outer diameter side. It is assembled in a state. In this assembled state, the inner length between the flange portions 32, 32 is substantially the same length L as the outer length of the flange portions 22, 22 of the bush receiving sleeve 2. Therefore, FIG. In the assembled state shown in FIG. 2, the flange portions 22 and 22 of the bush receiving sleeve 2 and the flange portions 32 and 32 of the mounting sleeve 3 are in contact with each other.

  The sleeve main body 21 of one sleeve half 2A in the bush receiving sleeve 2 and the sleeve main body 21 of the other sleeve half 2B have the same length, whereas one sleeve in the mounting sleeve 3 The sleeve main body 31 of the half body 3A and the sleeve main body 31 of the other sleeve half 3B are different in length, that is, the split position of the bush receiving sleeve 2 (the abutting position of the end portion 21a) and the attachment. The dividing position of the sleeve 3 (the abutting position of the end portion 31a) is shifted from each other, whereby the bush receiving sleeve 2 and the mounting sleeve 3 are fitted and integrated with each other.

  A pair of O-rings 4 as dust seals are interposed between the corner portions of the bush receiving sleeve 2 by the sleeve main body portion 21 and the flange portion 22 and the conical end surfaces 12b of the inner sleeve 12 of the bush main body 1, Close to both sides.

  The sliding bush configured as described above is formed on the inner periphery of the inner sleeve 12 of the bush body 1 formed as shown in FIG. The sleeve body portions 21 and 21 of the sleeve 2) are inserted until the end portions 21a and 21a are brought into contact with each other with the O-ring 4 inserted in advance. As shown in FIG. 3, the sleeve body portions 31 and 31 of the sleeve halves 3A and 3B (mounting sleeve 3) constituting the mounting sleeve 3 are press-fitted from both sides until the end portions 31a and 31a abut each other. Assembled into.

  In this sliding bush, the outer sleeve 11 in the bush body 1 is attached to one member in a connecting portion such as an arm of a vehicle suspension, for example, and the mounting sleeve 3 fitted and integrated with the bush receiving sleeve 2 is the arm or the like. A large radial displacement input due to an impact or the like is absorbed by the deformation of the elastic body 13 in the bush body 1, and a displacement input in the torsion direction is absorbed in the inner sleeve 12 in the bush body 1. Absorption is achieved by sliding between the peripheral surface (curved convex surface 12a) and the outer peripheral surface (curved concave surface 21b) of the bush receiving sleeve 2.

  Here, since the inner sleeve 12 is made of a low friction synthetic resin material such as nylon 66 containing graphite, for example, excellent slidability is ensured. In addition, since the O-ring 4 serving as a dust seal is interposed between the sleeve main body 21 and the flange portion 22 of the bush receiving sleeve 2 and the conical end surfaces 12b of the inner sleeve 12, the inner sleeve 12 It is possible to prevent external dust from intervening in the sliding portions of the curved convex surface 12a and the curved concave surface 21b of the bush receiving sleeve 2 and maintain good slidability for a long period of time. The O-ring 4 functions as a rubber spring that stably supports the inner sleeve 12.

  Further, since the curved convex surface 12a of the inner sleeve 12 of the bush body 1 and the curved concave surface 21b of the bush receiving sleeve 2 are fitted, the bush main body 1 and the bush receiving sleeve 2 (and the mounting sleeve 3) in the axial direction. Relative displacement is regulated.

  Furthermore, since the radius of curvature r2 of the curved concave surface 21b of the bush receiving sleeve 2 is larger than the radius of curvature r1 of the curved convex surface 12a of the inner sleeve 12 of the bush main body 1, when there is an input in the twisting direction, FIG. As shown, the bush body 1 and the bush receiving sleeve 2 (and the mounting sleeve 3) can be relatively displaced in the twisting direction. Moreover, since the inner sleeve 12 is made of a synthetic resin material, it can be appropriately deformed, and this also allows displacement in the twisting direction. Therefore, the load of the elastic body 13 in the twisting direction can be effectively reduced.

  FIG. 5 is a cross-sectional view showing a second example of the assembled state in the preferred embodiment of the sliding bush according to the present invention, and FIG. 6 is a cross-sectional view showing the third example.

  In the example of FIG. 5, the mounting sleeve 3 can be press-fitted into the inner periphery of the sleeve main body 21 of the bush receiving sleeve 2 and has a sleeve main body 31 having substantially the same length as the bush receiving sleeve 2 and one end thereof. 6 includes a single part having a flange 32 that opens to the outer diameter side. In the example of FIG. 6, the mounting sleeve 3 can be press-fitted into the inner periphery of the sleeve main body 21 of the bush receiving sleeve 2, and the bush receiving The bush receiving sleeve 2 is fitted to the sleeve main body 31 longer than the sleeve 2, the flange 32 opened from one end thereof to the outer diameter side, and the end of the sleeve main body 31 opposite to the flange 32. It consists of a metal ring 33 that prevents the metal from coming off. Thus, various attachment forms can be employed.

Reference Signs List 1 bush body 11 outer sleeve 12 inner sleeve 12a curved convex surface 13 elastic body 2 bush receiving sleeve 21b curved concave surface 3 mounting sleeve 4 O-ring (dust seal)

Claims (2)

A bushing body and a bush receiving sleeve disposed on the inner periphery of the bushing body, the bushing body being disposed on the inner circumferential side of the outer sleeve and the outer sleeve, the inner circumferential surface being the most axially intermediate portion The inner sleeve formed with a curved convex surface having a small diameter, and an elastic body having a rubber-like elasticity provided integrally between the outer sleeve and the inner sleeve, the bush receiving sleeve being a deformable synthetic resin material be made of a, the the outer peripheral surface curved convex surface and circumferentially slidably fitted are curved concave inner sleeve is formed, the curved concave outer peripheral surface of the bush receiving sleeve, the inner periphery of the inner sleeve A sliding bush characterized by having a larger radius of curvature than a curved convex surface . 2. The sliding bush according to claim 1, wherein a dust seal made of a rubber-like elastic material is interposed between both ends of the inner sleeve and the bush receiving sleeve .

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