Suspension arm and bush

Abstract

Provided are a suspension arm and a bush which are capable of absorbing three-dimensional forces, including a force in a prying direction.　This invention comprises: a base member 31 that has a spherical surface 31A; a link member 2 that has an arm part 21, and a spherical convex part 22 provided at one end of the arm part 21 and having a convexity in the same direction as the spherical surface 31A of the base member 31; and an elastic member 32 that is disposed between a portion of the spherical surface 31A of the base member 31 and the spherical convex part 22 of the link member 2, and that connects the base member 31 to the link member 2. The base member 31, the spherical convex part 22 of the link member 2, and the elastic member 32 are arranged concentrically.

Description

Suspension arms and bushings

[0001] The present invention relates to a suspension arm and a bushing.

[0002] Among suspension arms used in vehicle suspensions, there are those in which the link member and bushing are integrally constructed, as in Patent Document 1. This suspension arm is supported by a bracket so as to be rotatable about an axis extending in the horizontal direction perpendicular to the axial direction of the link member.

[0003] Japanese Patent Application Publication No. 6-127426

[0004] However, since the suspension arm described in Patent Document 1 can only rotate around a horizontal axis, i.e., on a vertical plane, the bush has high elasticity in the prying direction, making it difficult to absorb vibrations in the prying direction.

[0005] Therefore, an object of the present invention is to absorb forces in three-dimensional directions, including the prying direction.

[0006] In order to achieve the above object, the suspension arm of the present invention comprises a base member having a spherical surface, an arm portion and a link member having a spherical convex portion provided at one end of the arm portion and convex in the same direction as the spherical surface of the base member, and an elastic member arranged between the spherical portion of the base member and the spherical convex portion of the link member to connect the base member and the link member, wherein the base member, the spherical convex portion of the link member and the elastic member are arranged concentrically.

[0007] In addition, in order to achieve the above-mentioned object, the bushing of the present invention comprises a base member having a spherical surface, and an elastic member attached to the back side of the spherical surface of the base member and connecting the base member to a link member of a suspension, and is characterized in that when the elastic member connects the base member to the link member, the base member and the elastic member are arranged concentrically with a spherical convex portion that is provided at one end of the arm portion of the link member and is convex in the same direction as the spherical surface of the base member.

[0008] According to the present invention, it is possible to absorb forces in three-dimensional directions, including the prying direction. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments.

[0009] Fig. 4 is a diagram showing a mounting state of a suspension arm according to an embodiment of the present invention. Fig. 5 is an axial cross-sectional view showing one configuration example of a suspension arm. Fig. 6 is a plan view of Fig. 2 as seen from the direction of an X arrow. Fig. 7 is a plan view of Fig. 2 as seen from the direction of an Y arrow. Fig. 8 is a plan view of Fig. 4 with a fall-off prevention plate removed. Fig. 9 is an axial cross-sectional view showing the state of the suspension arm when a link member swings.

[0010] A suspension arm and a bushing according to an embodiment of the present invention will be described below with reference to Figures 1 to 6. In the following embodiment, a suspension arm and a bushing for a vehicle used in a vehicle suspension will be described as an example of one form of the suspension arm and bushing.

[0011] Fig. 1 is a diagram showing an attached state of a suspension arm 1 according to an embodiment of the present invention. Fig. 2 is an axial cross-sectional view showing an example of the configuration of the suspension arm 1. Fig. 3 is a plan view of Fig. 2 as seen from the direction of the X arrow. Fig. 4 is a plan view of Fig. 2 as seen from the direction of the Y arrow. Fig. 5 is a plan view of Fig. 4 with the fall-off prevention plate 6 removed.

[0012] 1, the suspension arm 1 has an integral structure in which the link member 2 and bushing 3 are integrated, and is attached to a fastened member 5 by fastening a bolt 41 to a nut 42. The fastened member 5 is, for example, a bracket on the vehicle body side or a bracket on the tire side.

[0013] In this embodiment, four bolts 41 are fastened to four nuts 42, but there are no particular restrictions on the size and number of the bolts 41 and nuts 42 as long as the suspension arm 1 is firmly fixed to the fastened member 5. Note that only two of the four bolts 41 and nuts 42 are shown in Figure 1.

[0014] The link member 2 is formed from a metal material such as iron, and as shown in FIG. 2, has a rod-shaped arm portion 21 with a hollow interior and a spherical convex portion 22 provided at one end of the arm portion 21.

[0015] The bush 3 is provided on the spherical convex portion 22 side of the link member 2 and has a base member 31 having a spherical surface 31A, and an elastic member 32 arranged between the spherical surface 31A portion of the base member 31 and the spherical convex portion 22 of the link member 2.

[0016] The base member 31 is formed by processing a metal material such as iron. As shown in Figures 3 and 5, the base member 31 has a generally rectangular outer frame with the lower end of the spherical surface 31A projecting outward. Bolt holes 310, through which bolts 41 are inserted, are provided at the four corners of the projecting portion of the base member 31.

[0017] The spherical convex portion 22 of the link member 2 and the spherical surface 31A of the base member 31 are convex in the same direction and are arranged concentrically. Therefore, the elastic member 32 connecting the link member 2 and the base member 31 is also formed in a spherical shape and is arranged concentrically with the spherical convex portion 22 of the link member 2 and the base member 31.

[0018] The elastic member 32 is molded from, for example, a rubber material, and is adhesively bonded by vulcanization to the spherical convex portion 22 of the link member 2 on one side and to the base member 31 on the other side. Note that the elastic member 32 does not necessarily have to be molded from a rubber material, and may be made of any material that can absorb vibrations.

[0019] FIG. 6 is an axial cross-sectional view showing the suspension arm 1 when the link member 2 swings.

[0020] In the suspension arm 1, the spherical convex portion 22 of the link member 2, the base member 31 of the bushing 3, and the elastic member 32 are spherical and arranged concentrically, so that when the arm portion 21 of the link member 2 swings, the elastic member 32 can freely expand and contract in any direction, including the twisting direction, of 360°. In other words, the arm portion 21 of the link member 2 can swing in any direction of 360° around the center of the spherical convex portion 22 as the central axis, as shown in Figure 6.

[0021] This allows the bushing 3 to absorb forces in three dimensions, including the prying direction, i.e., reduces the prying spring in the bushing 3, enabling the suspension arm 1 to absorb vibrations and shocks from all directions. Furthermore, the structure of this suspension arm 1 makes it possible, for example, to eliminate the protrusion of structures toward the tire side, thereby improving the degree of freedom in layout within the wheelhouse.

[0022] 2, the elastic members 32 are arranged in layers between the spherical convex portion 22 of the link member 2 and the base member 31. Specifically, the elastic members 32 are arranged in layers in the order of a first elastic layer 32A, a second elastic layer 32B, and a third elastic layer 32C from the spherical convex portion 22 side of the link member 2 toward the base member 31 side.

[0023] An intermediate member 33 that suppresses expansion of the elastic member 32 is sandwiched between adjacent layers of the elastic member 32. The intermediate member 33 is formed into a spherical shape by processing a metal material such as iron.

[0024] 2 and 5, in this embodiment, a first intermediate member 33A is sandwiched between the first elastic layer 32A and the second elastic layer 32B, and a second intermediate member 33B is sandwiched between the second elastic layer 32B and the third elastic layer 32C. The first intermediate member 33A and the second intermediate member 33B are both disposed concentrically with the spherical convex portion 22 of the link member 2, the base member 31, and the elastic member 32.

[0025] In the suspension arm 1, it is desirable that the bushing 3 be in a hard state when a force is applied from the other end (the end opposite the spherical convex portion 22) of the arm portion 21 toward the bushing 3 (i.e., in the axial direction). In this embodiment, the intermediate member 33 is sandwiched between adjacent layers of the elastic member 32, so that the elasticity of the elastic member 32 is high in the arrangement direction of the first elastic layer 32A, the second elastic layer 32B, and the third elastic layer 32C, i.e., in the axial direction of the arm portion 21.

[0026] In this embodiment, the bushing 3 has an elastic member 32 divided into three layers (a first elastic layer 32A, a second elastic layer 32B, and a third elastic layer 32C) and two intermediate members 33 (a first intermediate member 33A and a second intermediate member 33B), but there are no particular restrictions on the number of layers of the elastic member 32 and the number of intermediate members 33.

[0027] In this embodiment, a hole is formed in the center of each of the spherical surface 31A of the base member 31, the first intermediate member 33A, and the second intermediate member 33B. These holes are used in the manufacturing process of the suspension arm 1 when positioning the spherical convex portion 22 of the link member 2, the base member 31, the elastic member 32, and the intermediate member 33 so that they are concentrically arranged.

[0028] Specifically, in the process of vulcanizing the rubber material that will become the elastic member 32, a positioning rod is placed against the center of the spherical convex portion 22 of the link member 2, and the rubber material is poured in with the positioning rod inserted through these holes. As a result, as shown in Figures 2 and 3, a positioning hole 34 is formed in the bushing 3 that penetrates the base member 31, the elastic member 32, and the intermediate member 33 and is able to face the spherical convex portion 22 of the link member 2. Note that the positioning hole 34 does not necessarily have to be formed in the bushing 3; for example, the positioning hole 34 is not necessary if the various components are bonded after the vulcanization process of the rubber material.

[0029] Furthermore, in this embodiment, the suspension arm 1 includes a drop-off prevention plate 6 as a drop-off prevention member that prevents the link member 2 from dropping off, as shown in FIGS.

[0030] As shown in Fig. 4, the fall-off prevention plate 6 is formed into a substantially rectangular shape from a metal plate such as iron. Similar to the base member 31, the fall-off prevention plate 6 has bolt holes 61 at each of its four corners, through which bolts 41 are inserted. As shown in Fig. 1, the fall-off prevention plate 6 is fixed to the side of the base member 31 opposite the spherical surface 31A by fastening the bolts 41 to nuts 42.

[0031] 2 and 4, the anti-slip plate 6 has a through-hole 62 formed in its center, through which the arm portion 21 of the link member 2 passes. The diameter W of this through-hole 62 is set to be larger than the outer diameter W2 of the arm portion 21 and smaller than the outer diameter W3 of the spherical convex portion 22 (W2<W<W3). As a result, even if the elastic member 32 were to break, the spherical convex portion 22 of the link member 2 would catch on the anti-slip plate 6, preventing the link member 2 from being separated from the bushing 3 and the fastened member 5.

[0032] The embodiments of the present invention have been described above. Note that the present invention is not limited to the above-described embodiments and includes various other modifications. For example, the above-described embodiments and modifications have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configurations of the present embodiment and modifications with configurations of other embodiments, and it is also possible to add configurations of other embodiments to the configurations of the present embodiment and modifications. Furthermore, it is possible to add, delete, or replace part of the configurations of the present embodiment and modifications with other configurations.

[0033] 1: Suspension arm 2: Link member 3: Bush 6: Fall-off prevention plate (fall-off prevention member) 21: Arm portion 22: Spherical convex portion 31: Base member 31A: Spherical surface 32: Elastic member 32A: First elastic layer (layer) 32B: Second elastic layer (layer) 32C: Third elastic layer (layer) 33, 33A, 33B: Intermediate member 62: Through hole

Claims

1. A suspension arm comprising: a base member having a spherical surface; an arm portion and a link member having a spherical convex portion provided at one end of the arm portion and convex in the same direction as the spherical surface of the base member; and an elastic member arranged between the spherical portion of the base member and the spherical convex portion of the link member to connect the base member and the link member, wherein the base member, the spherical convex portion of the link member and the elastic member are arranged concentrically.

2. A suspension arm as claimed in claim 1, wherein the elastic member is arranged in layers between the base member and the spherical convex portion of the link member, and an intermediate member that suppresses expansion of the elastic member is sandwiched between adjacent layers of the elastic member, and the intermediate member is arranged concentrically with the base member, the spherical convex portion of the link member and the elastic member.

3. A suspension arm as claimed in claim 1, further comprising a fall prevention member fixed to the side of the base member opposite the spherical surface to prevent the link member from falling off, wherein the fall prevention member has a through hole formed therein through which the arm portion of the link member passes, and the diameter of the through hole is set to be larger than the outer diameter of the arm portion and smaller than the outer diameter of the spherical convex portion.

4. A bushing comprising: a base member having a spherical surface; and an elastic member attached to the back side of the spherical surface of the base member and connecting the base member to a link member of a suspension, wherein when the elastic member connects the base member to the link member, the base member and the elastic member are arranged concentrically with a spherical convex portion that is provided at one end of an arm portion of the link member and is convex in the same direction as the spherical surface of the base member.

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