Suspension bush and suspension bush assembly method

Abstract

To provide a suspension bushing that can improve manufacturing efficiency and reduce manufacturing costs by applying precompression to each rubber member of first and second bushing members with a pressing member in advance.SOLUTION: A suspension bushing has a first bushing member 12 and a second bushing member 13 each comprising: an outer cylinder 14 that is press-fitted into a collar 07 of a suspension, and has a cylindrical outer cylinder body 17, and a flange part 18 extending radially outward at one axial end part of the outer cylinder body; an inner tube 15 that is formed into a cylindrical shape with a nearly uniform or uniform outer diameter; a rubber member 16 that has a rubber body 19, and a cylindrical stopper part 20 protruding in an axial direction from a tip surface of the flange part of the outer cylinder; and a pressing member 21 that is press-fitted into one axial end part of the inner cylinder on the stopper part side, and flexibly deforms the rubber body in the opposite direction to the stopper part while compressing and deforming the stopper part in the axial direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a suspension bushing that is applied to, for example, a leaf-type or trailing arm-type suspension of an automobile. [Background technology]

[0002] A known conventional suspension bushing is that described in Patent Document 1. Fig. 1 is a perspective view showing a leaf-type suspension to which the present invention and conventional suspension bushings are applied, Fig. 7 is a vertical cross-sectional view showing the conventional suspension bushing, and Fig. 8 is a vertical cross-sectional view showing the conventional suspension bushing in a free state before it is assembled to the suspension.

[0003] As one type of suspension provided on the body of a vehicle such as a truck, a leaf-type suspension is commonly known, as shown in Fig. 1. On the vehicle body side, a housing 02 is disposed between two driving wheels 01, 01, and a pair of shock absorbers 03, 03 are provided on both sides of the housing 02.

[0004] The leaf-type suspension 04 is disposed between the axles of the two wheels 01, 01 and both ends of the housing 02, and has a plurality of plate-shaped springs 05 extending in the longitudinal direction of the vehicle, and is provided with a shackle 06 at each rear end. In addition, the front ends of the suspensions 04 are provided with spring eyes (collars) 07, and each collar 07 is provided with a suspension bushing 1.

[0005] 7, this suspension bushing 1 is made up of two members, a first bushing member 2 and a second bushing member 3, on the left and right sides of the figure, and is equipped with a pair of outer cylinders 4, 4 that are inserted into a collar member 07 on the suspension side from opposite axial directions, a pair of inner cylinders 5, 5 that are placed inside each of the outer cylinders 4, 4, and rubber members 6, 6 that are vulcanized and bonded between each of the outer cylinders 4, 4 and each of the inner cylinders 5, 5. Because the first and second bushing members 2, 3 have the same configuration, the following description will mainly focus on one side for ease of explanation.

[0006] The outer tube 4 has a cylindrical outer tube main body 4a and an outer tube flange portion 4b that is integrally formed at one axially outer end of the outer tube main body 4a and extends radially outward. The inner tube 5 has a cylindrical inner tube main body 5a and an inner tube flange portion 5b that is integrally formed at one axially outer end of the inner tube main body 5a and extends radially outward. The rubber member 6 has a cylindrical rubber main body 6a that is disposed between the outer tube main body 4a and the inner tube main body 5a, and an annular rubber portion 6b that is disposed at one axial end of the rubber main body 6a and is disposed between the outer tube flange portion 4b and the inner tube flange portion 5b.

[0007] When the first bushing member 2 and the second bushing member 3 are attached to the respective rubber members 6 on the collars 07 of the leaf-type suspension, pre-compression is applied between the two plate-shaped bracket pieces 08, 08 at the ends of the suspension by means of hexagonal bolts 09 and nuts 010.

[0008] That is, in the free state before being assembled between the bracket pieces 08, 08, the first bushing member 2 and the second bushing member 3 have an overall axial length of L2, as shown in FIG. 8 . They are then placed between the bracket pieces 08, 08 and tightened with a predetermined torque using hexagon bolts 09 and nuts 010. This compresses and deforms the annular rubber portions 6b, 6b between the outer cylinder flange portions 4b, 4b and the inner cylinder flange portions 5b, 5b. After the opposing ends 5c, 5c of the inner cylinders 5, 5 are butted together, a compressive force is applied to the rubber bodies 6a, 6a via the inner cylinder flange portions 5b, 5b, shortening the overall axial length to L1, which is shorter than L2. In this way, the tightening force of the hexagon bolts 09 and nuts 010 pre-compresses the rubber members 6, 6 in the axial direction.

[0009] The reason for pre-compressing each bushing member 2, 3 in this way is that, since the inner tubes 5, 5 of each bushing member 2, 3 are subjected to torsional forces due to vehicle vibrations, the rubber members 6, 6 are compressed and deformed in the axial direction in advance to ensure the amount of deformation in the extension direction (torsional direction), thereby improving the durability of each bushing member 2, 3 against torsion. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-225622 (Fig. 2) Summary of the Invention [Problem to be solved by the invention]

[0011] In the conventional suspension bushing described in the publication, pre-compression is imparted to the rubber members 6, 6 by first setting the serial length L2 of both bushing members 2, 3 in a free state to a large value, and then arranging the first and second bushing members 2, 3 between the bracket pieces 08, 08 on the suspension side, and then tightening them with the hexagon bolt 09 and nut 010 to compress and deform the rubber members 6, 6, thereby shortening their axial length to L1.

[0012] In this way, to obtain pre-compression, the axial lengths of both bushing members 2, 3 in a free state are set long in advance, and then shortened by the tightening force of the hexagon bolt 09 and nut 010 in the subsequent process of assembling the components, which requires highly accurate management of the axial lengths of both bushing members 2, 3. This makes the manufacturing process for each bushing member 2, 3 complicated, leading to a decrease in manufacturing efficiency and a rise in manufacturing costs.

[0013] Furthermore, in order to obtain the pre-compression, the inner cylinders 5, 5 must be provided with the inner cylinder flanges 5b, 5b in advance, which also raises concerns about a decrease in the manufacturing efficiency of the suspension bushing.

[0014] The present invention was devised in consideration of the technical problems with the conventional suspension bushings described above, and aims to provide a suspension bushing in which the rubber members of the first and second bushing members are pre-compressed by a pressing member, thereby eliminating the need for high axial dimensional precision of the bushing members, thereby improving manufacturing efficiency and reducing manufacturing costs. [Means for solving the problem]

[0015] The invention according to claim 1 of the present application is a suspension bushing that is disposed between a vehicle body and a suspension and includes an outer tube that is inserted into an end of the suspension, an inner tube that is disposed inside the outer tube, and a rubber member that is adhesively fixed between the outer tube and the inner tube, The outer cylinder has a cylindrical outer cylinder body and a flange portion extending radially outward from one axial end of the outer cylinder body, The inner cylinder is formed into a cylindrical shape with an outer diameter that is substantially uniform or uniform, the rubber member has a rubber main body disposed between the inner peripheral surface of the outer cylinder main body and the outer peripheral surface of the inner cylinder, and a cylindrical stopper portion integral with the rubber main body and protruding in the axial direction from a tip end surface of a flange portion of the outer cylinder, a pressing member that is press-fitted into one axial end of the inner tube on the stopper portion side, and that compresses and deforms the stopper portion in the axial direction while bending and deforming the rubber body via the outer tube in the direction opposite to the stopper portion; a first bushing member having a second bushing member arranged coaxially and adjacently symmetrically to the first bushing member and having the same configuration as the first bushing member; It is characterized by having: [Effects of the Invention]

[0016] According to the present invention, the rubber members of the first and second bushing members are pre-compressed by the pressing member, which eliminates the need for high axial dimensional accuracy in advance for each bushing member and eliminates the need for a flange on the inner cylinder, thereby improving manufacturing efficiency and reducing manufacturing costs. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a perspective view showing a leaf-type suspension to which the present invention and a conventional suspension bushing are applied. [Figure 2] 1 is a vertical cross-sectional view showing an embodiment of a suspension bushing according to the present invention. [Figure 3] 10 is a vertical cross-sectional view showing a state before a pressing member is press-fitted into one axial end of an inner cylinder of a first bushing member used in this embodiment. FIG. [Figure 4] 10 is a vertical cross-sectional view showing a state in which a pressing member is slightly press-fitted into one axial end of an inner cylinder of a first bushing member used in this embodiment. FIG. [Figure 5] 10 is a longitudinal cross-sectional view showing a state in which a pressing member is press-fitted to a predetermined range into one axial end of an inner cylinder of a first bushing member used in this embodiment. FIG. [Figure 6] 6A to 6C are explanatory views showing the amount of compressive deformation of the stopper portion of the rubber member and the displacement of the rubber body when the pressing members are successively pressed into one end of the inner cylinder shown in FIGS. 3 to 5, in which (a) corresponds to FIG. 3 and shows the state before the pressing members are pressed into the inner cylinder, (b) corresponds to FIG. 4 and shows the initial state after the pressing members are pressed into one end of the inner cylinder, and (c) corresponds to FIG. 5 and shows the state after the pressing members are pressed into one end of the inner cylinder. [Figure 7] FIG. 10 is a vertical cross-sectional view showing a conventional suspension bushing. [Figure 8] FIG. 1 is a vertical cross-sectional view showing a conventional suspension bush in a free state before being assembled to a suspension. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of a suspension bushing according to the present invention will be described with reference to the drawings. In this embodiment, the suspension bushing is mounted on a leaf-type suspension of a vehicle such as a truck. However, the suspension bushing of the present invention can also be applied to full trailing arm suspensions other than leaf-type suspensions.

[0019] FIG. 2 is a longitudinal cross-sectional view showing an embodiment of a suspension bushing according to the present invention, FIG. 3 is a longitudinal cross-sectional view showing a state before a pressing member is press-fitted into one axial end of the inner tube of the first bushing member used in this embodiment, FIG. 4 is a longitudinal cross-sectional view showing a state in which a pressing member has been slightly press-fitted into one axial end of the inner tube of the first bushing member used in this embodiment, and FIG. 5 is a longitudinal cross-sectional view showing a state in which a pressing member has been press-fitted to a predetermined extent into one axial end of the inner tube of the first bushing member used in this embodiment.

[0020] As described above, the suspension bushing 11 according to the present invention is provided on the collar 07 at the front end of the leaf-type suspension 04 on the rear side of the vehicle shown in FIG.

[0021] As shown in Figure 2, this suspension bushing 11 is composed of two left and right bushing members, a first bushing member 12 and a second bushing member 13, which are arranged coaxially and adjacently at symmetrical positions. The first and second bushing members 12 and 13 include a pair of outer cylinders 14, 14 inserted into a collar member 07 on the suspension side from opposite sides in the axial direction, a pair of inner cylinders 15, 15 arranged inside each of the outer cylinders 14, 14, and rubber members 16, 16 vulcanized and bonded between each of the outer cylinders 14, 14 and each of the inner cylinders 15, 15. For ease of explanation, the following will mainly describe only the first bushing member 12 on one side.

[0022] As shown in Figures 3 to 5, the outer tube 14 is formed by bending a thin iron-based metal plate material into a cylindrical shape, and has a cylindrical outer tube main body 17 and an outer tube flange portion 18 that is integrally formed at one end of the outer tube main body 17 in the axial direction and extends radially outward.

[0023] The inner cylinder 15 is formed as a straight cylinder with a substantially uniform or uniform outer diameter made of an iron-based metal material that is thicker than the outer cylinder 14, and has a bolt insertion hole 15a formed therethrough.

[0024] The rubber member 16 has a rubber main body 19 arranged between the inner peripheral surface 17a of the outer tube main body 17 and the outer peripheral surface 15b of the inner tube 15, and a stopper portion 20 integrally formed at one axial end of the rubber main body 19 and protruding axially from the tip surface 18a of the outer tube flange portion 18.

[0025] The rubber body 19 is formed in a cylindrical shape, and in the free state shown in Figure 3, the end face on the other axial end 15d side of the inner tube 15 has a first conical groove 19a formed in a downward slope from the outer tube 14 side to the inner tube 15 side.

[0026] The stopper portion 20 is formed in a cylindrical shape, with a flat annular tip surface 20a, and has a second conical groove 20b formed on the inner surface in a downward slope from the tip surface 20a to the edge on the side of one end 15c in the axial direction of the inner tube 15 of the rubber main body 19.

[0027] Also provided is a pressing member 21 that is press-fitted into one axial end 5b of the inner tube 5. This pressing member 21 is formed into a disk shape from a relatively thick iron-based metal plate, and has a press-fit hole 21a formed in the center that penetrates in the vertical direction in Figure 3 and is press-fitted and fixed to the outer peripheral surface of one end 15c of the inner tube 15. Also, the pressing member 21 is formed so that its outer diameter d is larger than the outer diameter of the stopper portion 20, and when press-fitted into one end 15c of the inner tube 15, it presses against the tip end surface 20a of the stopper portion 20 from the axial direction, compressing and deforming the stopper portion 20 and bending (displacing) the rubber main body 19 in the direction opposite to the stopper portion 20.

[0028] The second bushing member 3 has the same configuration as the first bushing member 2, and therefore a detailed description thereof will be omitted. [Functions and Effects of the Suspension Bush of the Present Embodiment] 6A and 6B are explanatory diagrams showing the amount of compressive deformation of the stopper portion of the rubber member and the displacement of the rubber body when the pressing members are successively pressed into one end of the inner cylinder shown in FIGS. 3 to 5, in which (a) corresponds to FIG. 3 and shows the state before the pressing member is pressed into the inner cylinder, (b) corresponds to FIG. 4 and shows the initial state after the pressing member is pressed into one end of the inner cylinder, and (c) corresponds to FIG. 5 and shows the state after the pressing member is pressed into one end of the inner cylinder.

[0029] The assembly procedure and effects of the components of the suspension bushing 1 of this embodiment will be described below.

[0030] First, as shown in Figures 3 and 6(a), the inner tube 15, which has the outer tube 14 and rubber member 16 fixed to its outer periphery, is fixed upright, for example, on a base 25 with the other end 15d facing downward. In this state, the pressing member 21 is moved downward from an upper position above one end 15c of the inner tube 15 using, for example, a press. Then, as shown in Figures 4 and 6(b), the lower surface 21b of the pressing member 21 comes into contact with the annular tip end surface 20a of the stopper portion 20, slightly compressing and deforming the stopper portion 20.

[0031] 5 and 6(c), the pressing member 21 is pressed into the one end 15c of the inner cylinder 15 from above through the press-fitting hole 21a by a predetermined amount while being positioned, and is then pressed downward to the maximum position (first step). This maximum pressing position is a position where the upper surface of the pressing member 21 and the upper surface of the one end 15c of the inner cylinder 15 are flush with each other.

[0032] At this time, the lower surface 21b of the pressing member 21 further presses downward against the tip surface 20a of the stopper portion 20. As a result, the stopper portion 20 is further compressively deformed via the second conical groove 20b, and the rubber body 19 is deflected downward in the axial direction via the first conical groove 19a (second step). As a result, the rubber member 16 is compressively deformed as a whole, and is placed in a pre-compressed state, as shown in Figures 5 and 6(c).

[0033] As described above, when the pressing member 21 applies a pressing force to the stopper portion 20, compressing and deforming it, the reaction force changes the relative axial position of the outer tube 14 and the inner tube 15, and this relative position becomes a position where the reaction force of the rubber main body 19 and the reaction force of the stopper portion 20 are balanced.

[0034] Therefore, if the spring constant of the rubber body 19 is KB, the spring constant of the stopper portion 20 is KA, the relative movement amount of the outer tube 14 with respect to the inner tube 15 is B, and the compressive deformation amount of the stopper portion 20 is A2, the equation KB×B=KA×A2 holds true.

[0035] Therefore, when manufacturing the suspension bushing 11 in this embodiment, KB, KA, A1, and B should be determined so that the relative axial movement dimension of the outer tube 14 and inner tube 15 shown in Figure 6(c) is A (the height of the stopper portion 20 after maximum compressive deformation is A3) and the pre-compression amount of the entire rubber member 16 is A2.

[0036] Furthermore, if the inclined surface length L1 of the first conical groove 19a of the rubber body 19 shown in Figure 6(a) is formed long in advance, the rubber body 19 will bend and displace in the axial direction due to pre-compression, and compression can also be applied to this rubber body 19 in the direction perpendicular to the axis.

[0037] Next, as shown in FIG. 2, the first bushing member 12 and the second bushing member 13 to which pre-compression has been applied are inserted into the collar 07 of the suspension from opposite sides in the axial direction via the respective outer cylinders 14, 14 (third step).

[0038] 2, the bushing members 12, 13 are sandwiched together with the opposing inner surfaces of the bracket pieces 22, 22 of the suspension abutting against the outer surfaces of the pressing members 21, 21 in the axial direction. Subsequently, the shaft 23a of the hexagon bolt 23 is inserted into each of the inner cylinders 15, 15, and the nut 24 threaded onto the tip of the shaft 23a of the hexagon bolt 23 is tightened via the head 23b, so that the opposing other ends 15d, 15c of the inner cylinders 15, 15 are butted together (fourth step). Through this series of steps, the first bushing member 12 and the second bushing member 13 are connected and fixed between the two bracket pieces 22, 22, completing the assembly work.

[0039] As described above, according to the suspension bushing 11 of this embodiment, before the first bushing member 12 and the second bushing member 13 are disposed between the suspension collar 07 and the bracket pieces 22, 22, the pressing members 21 are press-fitted into the axial ends 15c of the inner tubes 15 to press the stopper portions 20 of the rubber members 16 in the axial direction. This causes the stopper portions 20 to compress and deform via the second conical grooves 20b, and simultaneously causes the rubber bodies 19 to bend and displace in the axial direction opposite the stopper portions 20 via the outer tubes 14. This pre-compresses the rubber members 16, 16, thereby suppressing torsion of the inner tubes 15, 15 due to vehicle vibration. As a result, the torsional force exerted by the inner tubes 15, 15 on the rubber members 16, 16 is alleviated, improving the durability of the bushing members 12, 13.

[0040] In particular, in this embodiment, unlike the prior art described in the publication, in which pre-compression is applied to the rubber members 16, 16 by tightening the hexagon bolts 09 (23) and nuts 010 (24) when assembling the components, pre-compression is applied to the entire rubber members 16, 16 by compressing and deforming the stopper portions 20, 20 in advance using the pressing members 21, 21. This eliminates the need to increase the axial dimension of the bushing members 12, 13 by the amount of pre-compression, and does not require high axial dimensional accuracy. This simplifies the manufacturing process of the components, improving manufacturing efficiency and reducing manufacturing costs.

[0041] Furthermore, as described above, the suspension bushing 11 of this embodiment can be assembled to the suspension with the first bushing portion 12 and the second bushing portion 13 having been pre-compressed by the pressing members 21, 21 in advance to the stopper portions 20, 20 and the rubber main bodies 19, 19, i.e., the rubber members 16, 16, making it easier to assemble both bushing members 12, 13 to the suspension.

[0042] Furthermore, in this embodiment, it is not necessary to form inner cylinder flange portions on the inner cylinders 15, 15 in advance, as in the prior art, and in this respect too, manufacturability is improved.

[0043] Furthermore, in this embodiment, as described above, when the pressing members 21 are press-fitted into the one end portions 15c, 15b of the inner cylinders 15 and the stopper portions 20 are pressed axially by the pressing members 21, the stopper portions 20 are easily compressed and deformed via the second conical grooves 20b, and the rubber bodies 19 are easily deflected and displaced in the axial direction via the first conical grooves 19a, 19a in response to this. As a result, it becomes easier to effectively apply pre-compression to the rubber members 19, 19, and the pre-compression application work is also facilitated.

[0044] Although the pressing members 21, 21 are molded separately from the outer cylinders 14, 14 and the inner cylinders 15, 15, etc., they are formed with a simple structure, which makes the overall manufacturing process easier and helps prevent manufacturing costs from rising.

[0045] Furthermore, the thickness of each pressing member 21, 21 of each bushing member 12, 13 can be changed as desired depending on the specifications and application of the bushing member 12, 13. By making the thickness changeable in this way, the amount of press-fitting into the one end 15c, 15b of the inner cylinder 15, 15 can be changed, and therefore the characteristic value of pre-compression for each rubber member 16, 16 can be freely changed.

[0046] The present invention is not limited to the configuration of the above-described embodiment, and for example, the application of the suspension bushing can be further changed.

[0047] In addition, when press-fitting each pressing member 21 into each inner tube 15, 15, it is also possible to fix each inner tube 15, 15 by gripping the other end 15d of the inner tube 15 with a chuck or the like, without using a base 25 or the like. [Explanation of symbols]

[0048] 11...Suspension bushing 12...First bushing member 13...Second bushing member 14...Outer cylinder 15...Inner cylinder 15a...Bolt insertion hole 15b...Outer surface 15c...One end 15d...Other end 16...Rubber material 17...Outer cylinder body 18...Outer cylinder flange 19...Rubber body 20...Stopper part 20a...Tip surface 21...Pressing member 22...Bracket piece 23...Bolt 23a...Shaft part 23b…Head 24...Nut

Claims

1. A suspension bushing is disposed between a vehicle body and a suspension, and includes an outer tube inserted into an end of the suspension, an inner tube disposed inside the outer tube, and a rubber member adhesively fixed between the outer tube and the inner tube, The outer cylinder has a cylindrical outer cylinder body and a flange portion extending radially outward from one axial end of the outer cylinder body, The inner cylinder is formed into a cylindrical shape with an outer diameter that is substantially uniform or uniform, the rubber member has a rubber main body disposed between the inner peripheral surface of the outer cylinder main body and the outer peripheral surface of the inner cylinder, and a cylindrical stopper portion integral with the rubber main body and protruding in the axial direction from a tip end surface of a flange portion of the outer cylinder, a pressing member that is press-fitted into one axial end of the inner tube on the stopper portion side, and that compresses and deforms the stopper portion in the axial direction while bending and deforming the rubber body via the outer tube in the direction opposite to the stopper portion; a first bushing member having a second bushing member arranged coaxially and adjacently symmetrically to the first bushing member and having the same configuration as the first bushing member; A suspension bushing comprising:

2. 2. The suspension bushing according to claim 1, a first conical groove having a downwardly sloping inclined surface extending from the outer cylinder side to the inner cylinder side, at an end of the rubber body axially opposite to the stopper portion, in a free state before the pressing member is press-fitted into the inner cylinder; and a second conical groove having a downwardly sloping inclined surface extending from the stopper portion to the inner cylinder, on an inner peripheral surface of the inner cylinder side of the stopper portion.

3. 2. The suspension bushing according to claim 1, The suspension bushing is characterized in that the pressing member is formed in a disk shape from a metal material and has a press-fit hole formed in the center thereof for press-fitting into the outer peripheral surface of the inner cylinder.

4. 4. The suspension bushing according to claim 3, A suspension bushing characterized in that the shank of a bolt having a head at one end in the axial direction is disposed inside each inner tube of the first bushing member and the second bushing member, and a pair of bracket pieces on the suspension side are disposed in contact with each outer surface of each of the pressing members press-fitted into one end of each of the inner tubes, and by tightening nuts threaded onto the other axial ends of the bolts, the inner tubes are butted together in the axial direction, and the first bushing member and the second bushing member are connected and fixed between the two bracket pieces.

5. 2. The suspension bushing according to claim 1, A suspension bushing characterized in that the thickness of the pressing member is formed so as to be freely changeable.

6. 2. A method for assembling a suspension bushing according to claim 1, comprising the steps of: a first step of press-fitting a pressing member into one axial end of the inner cylinder; a second step of pressing the stopper portion from the axial direction with the pressing member to compressively deform the stopper portion in the axial direction and flexibly deform the rubber body via the outer cylinder in a direction opposite to the stopper portion; a third step of axially inserting the outer cylinders of the first bushing member and the second bushing member that have been subjected to the second step into collars of a suspension; a fourth step of inserting a shank of a bolt into each of the inner cylinders while abutting bracket pieces against the outer surfaces of the pressing members, and tightening nuts threaded onto the axial ends of the bolts to butt the opposing ends of the inner cylinders together in the axial direction; A method for assembling a suspension bush, comprising:

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