Suspension bushing and method for assembling suspension bushing

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 bush is described in the following Patent Document 1. Fig. 1 is a perspective view showing a leaf-type suspension to which the present invention and a conventional suspension bush are applied, Fig. 7 is a vertical cross-sectional view showing the conventional suspension bush, and Fig. 8 is a vertical cross-sectional view showing the conventional suspension bush 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 generally known, as shown in Fig. 1. On the vehicle body side, a housing 02 is disposed between two wheels 01, 01 on the driving side, 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, has a plurality of plate-shaped springs 05 extending in the front-rear direction of the vehicle, and is provided with a shackle 06 at its rear end. Also, the front end of the suspension 04 is provided with a spring eye (collar) 07, and each collar 07 is provided with a suspension bush 1.

[0005] 7, this suspension bushing 1 is composed of two members, a first bushing member 2 and a second bushing member 3, on the left and right sides in the figure, and includes a pair of outer cylinders 4, 4 inserted from opposite axial directions into a collar member 07 on the suspension side, a pair of inner cylinders 5, 5 disposed inside each of the outer cylinders 4, 4, and rubber members 6, 6 vulcanized and bonded between each of the outer cylinders 4, 4 and each of the inner cylinders 5, 5. Since the first and second bushing members 2, 3 have the same structure, for convenience of explanation, one side will be mainly explained below.

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

[0007] When the first bush member 2 and the second bush member 3 are attached to the collar 07 of the leaf-type suspension with respect to each rubber member 6, a pre-compression is applied between the two plate-shaped bracket pieces 08, 08 at the ends of the suspension by a hexagonal bolt 09 and a nut 010.

[0008] That is, in a free state before being assembled between both bracket pieces 08, 08, the first bush member 2 and the second bush member 3 have an overall axial length set to L2 as shown in FIG. 8. Then, they are placed between both bracket pieces 08, 08 and tightened with a predetermined torque by a hexagonal bolt 09 and a nut 010. As a result, the annular rubber parts 6b, 6b between the outer tube flange parts 4b, 4b and the inner tube flange parts 5b, 5b are compressed and deformed, and after the opposing ends 5c, 5c of both inner tubes 5, 5 are butted together, a compressive force is applied to each rubber body 6a, 6a via each inner tube flange part 5b, 5b, and the overall axial length is shortened to L1, which is shorter than L2. In this way, the rubber members 6, 6 of both bush members 2, 3 are precompressed in the axial direction by the tightening force of the hexagonal bolt 09 and the nut 010.

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

[0010] [Patent Document 1] JP 2001-225622 A (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 each rubber member 6, 6 by previously setting a large serial length L2 of both bush members 2, 3 in a free state, and then arranging the first and second bush members 2, 3 between both bracket pieces 08, 08 on the suspension side, and tightening them with a hexagonal bolt 09 and a nut 010 to compressively deform the rubber members 6, 6 and shorten their axial length to L1, as described above.

[0012] In this way, in order to obtain the 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 hexagonal bolt 09 and the nut 010 in the post-process of assembling each component, so that it is necessary to control the axial lengths of both bushing members 2, 3 with high precision. This makes the manufacturing process for each bushing member 2, 3 complicated, leading to a decrease in the efficiency of the manufacturing process and a rise in the operating costs.

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

[0014] The present invention has been 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 each bushing member in advance, 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 end of the outer cylinder body in an axial direction, The inner cylinder is formed into a cylindrical shape having a substantially uniform or uniform outer diameter, the rubber member has a rubber main body disposed between an inner peripheral surface of the outer tube main body and an outer peripheral surface of the inner tube, 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 tube, a pressing member that is press-fitted into one axial end of the inner tube on the stopper portion side, and that compressively deforms the stopper portion in the axial direction while bending the rubber body via the outer tube in a direction opposite to the stopper portion; A first bushing member having A second bush member is disposed coaxially and adjacently symmetrically to the first bush member and has the same configuration as the first bush member; The present invention is characterized in that it has the following features. Effect 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 dimensional accuracy in the axial direction of each bushing member and eliminates the need for a flange on the inner cylinder, thereby improving the efficiency of manufacturing and reducing manufacturing costs. [Brief description 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 bush are applied; [Diagram 2] 1 is a vertical cross-sectional view showing an embodiment of a suspension bush according to the present invention. [Diagram 3] 4 is a vertical cross-sectional view showing a state before a pressing member is press-fitted into one axial end portion of an inner cylinder of a first bushing member used in the present embodiment. FIG. [Figure 4] 1 is a vertical cross-sectional view showing a state in which a pressing member is slightly press-fitted into one axial end portion of an inner cylinder of a first bushing member used in this embodiment. FIG. [Diagram 5] 10 is a vertical 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] 6 is an explanatory diagram showing the amount of compressive deformation of the stopper portion of the rubber member and the displacement of the rubber body when the pressing member is successively pressed into one end of the inner tube shown in FIGS. 3 to 5, in which (a) shows the state before the pressing member is pressed into the inner tube corresponding to FIG. 3, (b) shows the initial state where the pressing member is pressed into one end of the inner tube corresponding to FIG. 4, and (c) shows the state where the pressing member is pressed into one end of the inner tube corresponding to FIG. 5. [Figure 7] FIG. 11 is a vertical cross-sectional view showing a conventional suspension bushing. [Figure 8] 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 PREFERRED EMBODIMENTS

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

[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 pressed into one axial end of an inner tube of a 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 pressed into one axial end of an inner tube of a 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 pressed into one axial end of an inner tube of a first bushing member used in this embodiment to a predetermined extent.

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

[0021] 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 symmetrically adjacent to each other. The first and second bushing members 12, 13 each 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 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-walled 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 integral with 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 surface 17a of the outer tube main body 17 and the outer 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 in the axial direction 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 inclination from the outer tube 14 side to the inner tube 15 side.

[0026] The stopper portion 20 is formed in a cylindrical shape, has a circular annular tip surface 20a that is formed flat, and has a second conical groove 20b formed in an inner peripheral surface with 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 body 19.

[0027] A pressing member 21 is provided which is press-fitted into one end 5b in the axial direction of the inner tube 5. The pressing member 21 is formed by forming a relatively thick iron-based metal plate into a disk shape, and a press-fit hole 21a is formed in the center thereof, penetrating in the vertical direction in Fig. 3, so that the pressing member 21 is press-fitted and fixed to the outer peripheral surface of one end 15c of the inner tube 15. 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 pressed into one end 15c of the inner tube 15, the pressing member 21 presses 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 body 19 in the opposite direction to the stopper portion 20.

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

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

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

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

[0033] As described above, when a pressing force is applied to the stopper portion 20 by the pressing member 21, causing compression and deformation, the relative axial position of the outer tube 14 and the inner tube 15 changes due to the reaction force, and this relative position becomes a position where the reaction force of the rubber 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 the 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 be deflected and displaced in the axial direction by pre-compression, and compression can also be applied to the rubber body 19 in the direction perpendicular to the axis.

[0037] Next, as shown in FIG. 2, the first bush member 12 and the second bush 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 outer cylinders 14, 14 (third step).

[0038] 2, the two bushing members 12, 13 are sandwiched while the opposing inner faces of the two bracket pieces 22, 22 of the suspension are brought into axial contact with the outer faces of the pressing members 21, 21. Then, the shaft 23a of the hexagonal bolt 23 is inserted into the inside of each of the inner cylinders 15, 15, and the nut 24 screwed onto the tip of the shaft 23a of the hexagonal 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 bush member 12 and the second bush 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 bush 11 of this embodiment, before the first bush member 12 and the second bush member 13 are arranged between the collar 07 of the suspension and both bracket pieces 22, 22, the pressing members 21, 21 are pressed into one end 15c of the axial direction of the inner tubes 15, 15 to press the stopper portions 20, 20 of the rubber members 16, 16 from the axial direction. As a result, the stopper portions 20, 20 are compressed and deformed through the second conical grooves 20b, 20b, and at the same time, the rubber bodies 19, 19 are deflected and displaced in the axial direction opposite to the stopper portions 20, 20 through the outer tubes 14, 14. As a result, the rubber members 16, 16 are precompressed, so that the twisting of the inner tubes 15, 15 due to the vibration of the vehicle can be suppressed. As a result, the force in the twisting direction applied to the rubber members 16, 16 from the inner tubes 15, 15 is alleviated, and the durability of the bush members 12, 13 can be improved.

[0040] In particular, in this embodiment, unlike the prior art described in the publication, in which the rubber members 16, 16 are precompressed by the fastening force of the hexagonal bolt 09 (23) and nut 010 (24) when assembling the components, the stopper portions 20, 20 are compressed and deformed in advance by the pressing members 21, 21, thereby precompressing the entire rubber members 16, 16. Therefore, it is not necessary to increase the axial dimension of each bushing member 12, 13 by the amount of precompression in order to perform precompression, and high dimensional accuracy in the axial direction is not required. This makes it easier to manufacture the components, improving the efficiency of the manufacturing process and reducing the operating costs.

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

[0042] Furthermore, in this embodiment, it is no longer necessary to form inner cylinder flange portions in advance on each of the inner cylinders 15, 15 as in the conventional technology, and in this respect too, manufacturability is improved.

[0043] Furthermore, in this embodiment, as described above, when the pressing members 21, 21 are pressed into the one end 15c, 15b side of each inner cylinder 15, 15 and the stopper portions 20, 20 are pressed in the axial direction by the pressing members 21, 21, the stopper portions 20, 20 are easily compressed and deformed via the second conical groove 20b, and the rubber bodies 19, 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 precompression to the rubber members 19, 19, and the precompression application work becomes smooth.

[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 entire manufacturing process easier and prevents the 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 members 12, 13. By making the thickness variable in this way, the amount of press-fitting into the one ends 15c, 15b of the inner cylinders 15, 15 can be changed, so that the characteristic value of the pre-compression for each rubber member 16, 16 can be freely changed.

[0046] The present invention is not limited to the configurations of the above-described embodiments, and for example, the application of the suspension bushings may be further changed.

[0047] In addition, as a method of fixing each of the inner tubes 15, 15 when pressing each of the pressing members 21, 21 into each of the inner tubes 15, 15, it is also possible to fix the inner tubes 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 bushings 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 comprising: an outer tube disposed between a vehicle body and a suspension and 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 end of the outer cylinder body in an axial direction, The inner cylinder is formed into a cylindrical shape having a substantially uniform or uniform outer diameter, the rubber member has a rubber main body disposed between an inner peripheral surface of the outer tube main body and an outer peripheral surface of the inner tube, 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 tube, a pressing member that is press-fitted into one axial end of the inner tube on the stopper portion side, and that compressively deforms the stopper portion in the axial direction while bending the rubber body via the outer tube in a direction opposite to the stopper portion; A first bushing member having a second bush member arranged coaxially and adjacently symmetrically to the first bush member and having the same configuration as the first bush member; A suspension bushing comprising:

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

3. 2. The suspension bushing according to claim 1, 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 a shank of a bolt having a head at one end in the axial direction is disposed inside each of the inner tubes of the first bushing member and the second bushing member, a pair of bracket pieces on the suspension side are disposed in contact with each outer surface of each of the pressing members which are press-fitted into one end of each of the inner tubes, and by tightening a nut screwed onto the other axial end of the bolt, 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 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 the 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 in the axial direction with the pressing member to compressively deform the stopper portion in the axial direction and flexibly deform the rubber body in the direction opposite to the stopper portion via the outer tube; a third step of axially inserting the outer cylinders of the first bush member and the second bush 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 a bracket piece against each of the outer surfaces of each of the pressing members, and tightening a nut screwed onto an axial end of the bolt 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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