Bush, vibration control structure, and manufacturing method of vibration control structure

Abstract

To provide a bush which enables reduction of rigidity in a twisting direction, and to provide a vibration control structure and a manufacturing method of the vibration control structure.SOLUTION: A bush includes a bracket part having an outer cylinder part, an inner cylinder part, and a body rubber part connecting the outer cylinder part with the inner cylinder part. The bush includes a pair of split assemblies. Each split assembly includes: a split bracket member forming a part of the bracket part and having a split outer cylinder part forming a part of the outer cylinder part in a circumferential direction; a split inner cylinder member forming a part of the inner cylinder part in the circumferential direction; and a split body rubber member forming a part of the body rubber part in the circumferential direction and connecting the split outer cylinder part of the split bracket member with the split inner cylinder member. An outer peripheral surface of the split inner cylinder member has: a pair of first joint parts joined to the split body rubber member at ends on both sides in the circumferential direction of the split inner cylinder member on a cross section viewed in a direction perpendicular to an axis in at least parts in an axial direction; and a first non-joint part which extends between the pair of first joint parts in the circumferential direction and is not joined to the split body rubber member.SELECTED DRAWING: Figure 15

Description

[Technical field]

[0001] The present invention relates to a bush, an anti-vibration structure, and a method for manufacturing an anti-vibration structure. [Background technology]

[0002] Conventionally, there is a bush equipped with a cylindrical rubber elastic body (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-147408 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional bushes, there is room for improvement in terms of the rigidity in the torsional direction.

[0005] The present invention aims to provide a bush and an anti-vibration structure that can reduce torsional rigidity, as well as a method for manufacturing an anti-vibration structure that can obtain an anti-vibration structure that can reduce torsional rigidity. [Means for solving the problem]

[0006] [1] A bracket portion having an outer cylinder portion; An inner cylinder portion; a main rubber portion that connects the outer cylinder portion and the inner cylinder portion to each other; A bushing comprising: The bushing includes a pair of split assemblies; Each of the split assemblies includes: a split bracket member including a split outer cylinder portion that constitutes a part of the bracket portion and constitutes a circumferential part of the outer cylinder portion; A divided inner cylinder member that constitutes a circumferential portion of the inner cylinder portion; a split main body rubber member that constitutes a circumferential portion of the main body rubber portion and connects the split outer cylinder portion and the split inner cylinder member of the split bracket member; Equipped with In each of the split assemblies, the outer circumferential surface of the split inner cylinder member has, when viewed in a cross section perpendicular to the axis, at least a portion of the axial direction of the split inner cylinder member, a pair of first joint portions joined to the divided main body rubber member at both circumferential end portions of the divided inner cylinder member; a first non-joined portion that extends between the pair of first joined portions in the circumferential direction and is not joined to the divided main body rubber member; Bush has. This makes it possible to reduce the rigidity in the torsional direction.

[0007] [2] In each of the split assemblies, the outer circumferential surface of the split inner cylinder member has, when viewed in an axial cross section, at least a portion of the circumferential direction of the split inner cylinder member, a pair of second joint portions joined to the divided main body rubber member at both axial ends of the divided inner cylinder member; a second non-joined portion that extends between the pair of second joint portions in the axial direction and is not joined to the divided main body rubber member; The bushing described in [1] has a This allows the rigidity in the torsional direction to be further reduced.

[0008] [3] A bush as described in [1] or [2], wherein in each of the split assemblies, the outer peripheral surface of the split inner tube member has a protrusion that protrudes toward the outer peripheral side at the axial center of the split inner tube member in at least a portion of the circumferential direction of the split inner tube member when viewed in axial cross section. This makes it easier to suppress displacement of the split inner cylinder members in the axial direction.

[0009] [4] A bush according to any one of [1] to [3], a rod-shaped member extending along an inner circumferential side of the inner cylindrical portion of the bush; A vibration-proof structure comprising: The inner cylindrical portion is joined to the rod-shaped member, This makes it possible to reduce the rigidity in the torsional direction.

[0010] [5] A method for manufacturing the vibration-proof structure according to [4], comprising the steps of: a bushing manufacturing process for manufacturing the bushing; a rod-shaped member joining process for joining the inner cylindrical portion to the rod-shaped member in a state in which the rod-shaped member is extended to an inner peripheral side of the inner cylindrical portion of the bush; A method for manufacturing a vibration-proof structure comprising the steps of: This makes it possible to obtain a vibration-proof structure that can reduce rigidity in the torsional direction. Effect of the Invention

[0011] According to the present invention, it is possible to provide a bush and an anti-vibration structure capable of reducing rigidity in the torsional direction, as well as a method for manufacturing an anti-vibration structure that can obtain an anti-vibration structure capable of reducing rigidity in the torsional direction. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a schematic diagram for explaining the rod-shaped member arrangement process in the vibration-proof structure manufacturing method according to the first embodiment of the present invention, and is an AA cross-sectional view showing the bush and vibration-proof structure according to the first embodiment of the present invention in a state before a rod-shaped member is arranged on the inner side of the bush just before the rod-shaped member arrangement process, taken along line AA in FIG. 2 which is parallel to the axial direction. [Diagram 2] FIG. 1 is a schematic diagram for explaining the rod-shaped member arrangement process in the method for manufacturing an anti-vibration structure according to the first embodiment of the present invention, and is a cross-sectional view along line BB in FIG. 1 which is parallel to the axial direction and shows the bush and anti-vibration structure according to the first embodiment of the present invention in the state shown in FIG. [Diagram 3]FIG. 2 is a schematic diagram for explaining the rod-shaped member arrangement step in the vibration-proof structure manufacturing method according to the first embodiment of the present invention, and is a cross-sectional view perpendicular to the axis, which is a schematic view of the bush and vibration-proof structure according to the first embodiment of the present invention in a state in which a rod-shaped member is arranged on the inner side of the bush immediately after the rod-shaped member arrangement step, in the same cross section as FIG. 1. [Figure 4] FIG. 2 is a schematic diagram for explaining an example of a rod-shaped member joining process in a method for manufacturing an anti-vibration structure according to a first embodiment of the present invention, and is an axial cross-sectional view that shows the bush and anti-vibration structure according to the first embodiment of the present invention during the rod-shaped member joining process, in a cross-section similar to that shown in FIG. [Diagram 5] FIG. 2 is a schematic diagram for explaining another example of the rod-shaped member joining process in the method for manufacturing an anti-vibration structure according to the first embodiment of the present invention, and is an axial cross-sectional view that shows the bush and anti-vibration structure according to the first embodiment of the present invention during the rod-shaped member joining process, in a cross-section similar to that of FIG. [Figure 6] 8 is a schematic diagram for explaining the bracket portion attachment process in the method for manufacturing an anti-vibration structure according to the first embodiment of the present invention; FIG. 8 is a cross-sectional view in the axial direction generally showing the bush and anti-vibration structure according to the first embodiment of the present invention immediately after the bracket portion attachment process, in a cross-section similar to that of FIG. 1; and FIG. 8 is a CC cross-sectional view generally showing the cross-section along line CC in FIG. 8 which is parallel to the axial direction. [Figure 7] 7 is a DD cross-sectional view showing the bush and the vibration-proof structure in the state shown in FIG. 6, taken along the line DD in FIG. 8 which is parallel to the axial direction. [Figure 8] 7 is a top view that shows a schematic view of the bush and the vibration-proof structure in the state shown in FIG. 6, as viewed in a direction from the first vertical side to the second vertical side. FIG. [Figure 9] 7 is a bottom view showing the bush and the vibration-proof structure in the state shown in FIG. 6, viewed from the second vertical side toward the first vertical side. FIG. [Figure 10]FIG. 11 is a schematic diagram for explaining the rod-shaped member arrangement step in the vibration-proof structure manufacturing method according to the second embodiment of the present invention, and is an E-E cross-sectional view that shows a schematic cross-section of the bush and vibration-proof structure according to the second embodiment of the present invention in a state before a rod-shaped member is arranged on the inner side of the bush just before the rod-shaped member arrangement step, taken along the E-E line in FIG. 11 that is parallel to the axial direction. [Figure 11] 10 is a schematic diagram for explaining the rod-shaped member arrangement process in a method for manufacturing an anti-vibration structure according to a second embodiment of the present invention, and is an FF cross-sectional view that diagrammatically shows the bush and anti-vibration structure according to the second embodiment of the present invention in the state shown in FIG. 10, in a cross-section taken along line FF in FIG. 10 that is parallel to the axial direction. [Figure 12] FIG. 11 is a schematic diagram for explaining the rod-shaped member arrangement step in the vibration-proof structure manufacturing method according to the second embodiment of the present invention, and is a cross-sectional view perpendicular to the axis, which is a schematic view of the bush and vibration-proof structure according to the second embodiment of the present invention in a state in which a rod-shaped member is arranged on the inner side of the bush immediately after the rod-shaped member arrangement step, in the same cross section as in FIG. [Figure 13] FIG. 13 is a schematic diagram for explaining an example of a rod-shaped member joining process in a method for manufacturing an anti-vibration structure according to a second embodiment of the present invention, and is an axial cross-sectional view generally showing the anti-vibration structure according to the second embodiment of the present invention during the rod-shaped member joining process, in a cross-section similar to that shown in FIG. [Figure 14] FIG. 13 is a schematic diagram for explaining another example of a rod-shaped member joining process in a method for manufacturing an anti-vibration structure according to the second embodiment of the present invention, and is an axial cross-sectional view that shows the bush and anti-vibration structure according to the second embodiment of the present invention during the rod-shaped member joining process in a cross-section similar to that of FIG. [Figure 15] 16 is a schematic diagram for explaining the bracket portion mounting process in the method for manufacturing an anti-vibration structure according to the second embodiment of the present invention; FIG. 17 is a cross-sectional view in the axial direction generally showing the bush and anti-vibration structure according to the second embodiment of the present invention immediately after the bracket portion mounting process, in a cross-section similar to that of FIG. 10; and FIG. 18 is a cross-sectional view in the GG direction generally showing the cross-section along line GG in FIG. 16 which is parallel to the axial direction. [Figure 16]16 is a cross-sectional view showing the bush and the vibration-proof structure in the state shown in FIG. 15, taken along the line HH in FIG. 15 which is parallel to the axial direction. [Figure 17] 17 is an axial cross-sectional view that shows, in a simplified manner, a modified example of the bush and vibration-proof structure according to the second embodiment of the present invention, in an axial cross-section similar to that of FIG. 16. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The bushing, vibration-proof structure, and vibration-proof structure manufacturing method of the present invention are suitable for use in the connecting portion between a rod-shaped member in a vehicle (e.g., a torsion bar of the vehicle, particularly a stabilizer bar) and a vibration-receiving member (e.g., a part of the vehicle body).

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a bush, an anti-vibration structure, and a method for manufacturing an anti-vibration structure according to the present invention will be described with reference to the drawings.

[0015] 1 to 9 are drawings for explaining a bush, an anti-vibration structure, and a method for manufacturing an anti-vibration structure according to a first embodiment of the present invention, as well as modified examples thereof. The method for manufacturing an anti-vibration structure according to the first embodiment of the present invention is used for manufacturing an anti-vibration structure S according to the first embodiment of the present invention as illustrated in Figs. 6 to 9. The anti-vibration structure S according to the first embodiment of the present invention comprises a bush 1 according to the first embodiment of the present invention and a rod-shaped member R. 10 to 17 are diagrams for explaining a bush, an anti-vibration structure, and a method for manufacturing an anti-vibration structure according to a second embodiment of the present invention, as well as modified examples thereof. The method for manufacturing an anti-vibration structure according to the second embodiment of the present invention is used to manufacture an anti-vibration structure S according to the second embodiment of the present invention as exemplified in the examples of Figs. 15 to 16 and the modified example of Fig. 17. The anti-vibration structure S according to the second embodiment of the present invention includes a bush 1 according to the second embodiment of the present invention and a rod-shaped member R. The method for manufacturing an anti-vibration structure according to the second embodiment of the present invention, which will be described with reference to Figs. 10 to 17, is basically the same as the method for manufacturing an anti-vibration structure according to the first embodiment of the present invention, which will be described with reference to Figs. 1 to 9, and only the configurations of the bush 1 and the anti-vibration structure S to be manufactured are different.

[0016] For convenience of explanation, the first and second embodiments will be explained in parallel below. Unless otherwise specified, the matters described below are applicable to each of the examples (each embodiment and their modified examples) described in this specification.

[0017] In this specification, when describing the bush 1 and the vibration-proof structure S, for convenience, unless otherwise specified, the description will be given of the structure when no input is applied to the bush 1 or the vibration-proof structure S and the bush 1 or the vibration-proof structure S is in a stationary, normal state, as shown in each figure.

[0018] First, the basic configuration of the bush 1 and the vibration isolation structure S in the first and second embodiments will be described.

[0019] 6 to 9, 15 to 17, etc., the bushing 1 includes a bracket portion 2 having an outer cylinder portion 25, an inner cylinder portion 3, and a main rubber portion 4. The main rubber portion 4 connects the outer cylinder portion 25 and the inner cylinder portion 3 to each other.

[0020] The bush 1 includes a pair of split assemblies 5 . Each split assembly 5 includes a split bracket member 2D, a split inner cylinder member 3D, and a split main body rubber member 4D. The split bracket member 2D constitutes a part of the bracket portion 2. The split bracket member 2D has a split outer cylinder portion 25D that constitutes a part of the outer cylinder portion 25 in the circumferential direction. The split inner cylinder member 3D constitutes a circumferential portion of the inner cylinder portion 3. The split inner cylinder member 3D is located on the inner circumferential side of the split outer cylinder portion 25D. The split main body rubber member 4D constitutes a circumferential portion of the main body rubber part 4. The split main body rubber member 4D is located radially between the split outer cylinder portion 25D and the split inner cylinder member 3D of the split bracket member 2D, and connects the split outer cylinder portion 25D and the split inner cylinder member 3D. In this manner, the bush 1 is divided into two split assemblies 5 .

[0021] In this specification, one of the pair of split assemblies 5 is referred to as the "first split assembly 51," and the other of the pair of split assemblies 5 is referred to as the "second split assembly 52." In addition, the split bracket member 2D, split outer cylinder portion 25D, split inner cylinder member 3D, and split main body rubber member 4D of the first split assembly 51 are referred to as the first split bracket member 2D1, first split outer cylinder portion 25D1, first split inner cylinder member 3D1, and first split main body rubber member 4D1, respectively. In addition, the split bracket member 2D, split outer cylinder portion 25D, split inner cylinder member 3D, and split main body rubber member 4D of the second split assembly 52 are referred to as the second split bracket member 2D2, second split outer cylinder portion 25D2, second split inner cylinder member 3D2, and second split main body rubber member 4D2, respectively.

[0022] The bracket portion 2 is composed of a pair of split bracket members 2D (a first split bracket member 2D1 and a second split bracket member 2D2). The outer cylinder portion 25 of the bracket portion 2 is composed of a pair of split outer cylinder portions 25D (a first split outer cylinder portion 25D1 and a second split outer cylinder portion 25D2). The inner cylinder portion 3 is composed of a pair of divided inner cylinder members 3D (a first divided inner cylinder member 3D1 and a second divided inner cylinder member 3D2). The main body rubber portion 4 is composed of a pair of divided main body rubber members 4D (a first divided main body rubber member 4D1 and a second divided main body rubber member 4D2).

[0023] 1-2, 10-11, each split assembly 5 is formed integrally by connecting a split bracket member 2D, a split inner cylinder member 3D, and a split main body rubber member 4D to each other. The pair of split assemblies 5 are separated from each other before being joined to the rod-shaped member R, and are configured to be able to be assembled to each other (FIGS. 3, 6, 12, 15).

[0024] When the pair of split assemblies 5 are separated from each other (FIGS. 1 and 10), the central axes O25 of the split outer cylinder portions 25D and the central axes O3 of the split inner cylinder members 3D are separated from each other. Here, the central axis O25 of the split outer cylinder portion 25D corresponds to the central axis of an imaginary cylinder shape formed by extending the split outer cylinder portion 25D all around. The central axis O3 of the split inner cylinder member 3D corresponds to the central axis of an imaginary cylinder shape formed by extending the split inner cylinder member 3D all around.

[0025] In a state where a pair of split assemblies 5 are assembled in close contact with each other (hereinafter also referred to as the "closely assembled state") (FIGS. 6 and 15), the split outer tube portions 25D come into contact with each other to form a cylindrical outer tube portion 25, the split inner tube members 3D come into contact with each other to form a cylindrical inner tube portion 3, and the split main body rubber members 4D come into contact with each other to form a cylindrical main body rubber portion 4. At this time, the central axes O25 of the split outer tube portions 25D coincide with each other to form the central axis O25 of a single outer tube portion 25, and the central axes O3 of the split inner tube members 3D coincide with each other to form the central axis O3 of a single inner tube portion 3. At this time, the inner cylinder portion 3 is located on the inner peripheral side of the outer cylinder portion 25. In this state, the inner cylinder portion 3 is disposed coaxially with the outer cylinder portion 25. In other words, the central axis O3 of the inner cylinder portion 3 coincides with the central axis O25 of the outer cylinder portion 25.

[0026] In this specification, the central axis O3 of the inner cylindrical portion 3 or the divided inner cylindrical member 3D is regarded as the central axis O3 of the bush 1 and the vibration-proof structure S, respectively. Furthermore, in this specification, unless otherwise specified, the direction parallel to the central axis O3 of the bushing 1 and the vibration-proof structure S is referred to as the "axial direction (AD)", the side farther from the center of the bushing 1 and the vibration-proof structure S in the axial direction (AD) is referred to as the "axial outer side", the side closer to the center of the bushing 1 and the vibration-proof structure S in the axial direction (AD) is referred to as the "axial inner side", the direction perpendicular to the central axis O3 of the bushing 1 and the vibration-proof structure S is referred to as the "axial direction", the side closer to the central axis O3 of the bushing 1 and the vibration-proof structure S is referred to as the "inner circumference side", the side farther from the central axis O3 of the bushing 1 and the vibration-proof structure S is referred to as the "outer circumference side", the circumferential direction centered on the central axis O3 of the bushing 1 and the vibration-proof structure S is referred to as the "circumferential direction", and the radial direction centered on the central axis O3 of the bushing 1 and the vibration-proof structure S is referred to as the "radial direction". For convenience, in this specification, a direction perpendicular to the axial direction (AD) is referred to as the "longitudinal direction (VD)", one side in the longitudinal direction (VD) is referred to as the "first longitudinal side (VD1)", and the other side in the longitudinal direction (VD) is referred to as the "second longitudinal side (VD2)". Furthermore, a direction perpendicular to the axial direction (AD) and the longitudinal direction (VD) is referred to as the "width direction (WD)", a side in the width direction (WD) closer to the center of the bush 1 and the vibration-proof structure S is referred to as the "inner width direction", and a side in the width direction (WD) farther from the center of the bush 1 and the vibration-proof structure S is referred to as the "outer width direction". In each drawing, each of these directions is indicated by an arrow. For example, the bushing 1 and the vibration-proof structure S may be oriented such that the axial direction AD is substantially horizontal, the longitudinal direction VD is substantially vertical, and the first longitudinal side VD1 is on the upper side in the substantially vertical direction when in use. However, the bushing 1 and the vibration-proof structure S may be oriented such that the axial direction AD faces in any direction when in use.

[0027] In the examples of each figure, the outer tube portion 25 is configured to have an approximately cylindrical shape when the pair of split assemblies 5 are closely assembled together (Figures 6 and 15), but it may be configured to have any cylindrical shape when the pair of split assemblies 5 are closely assembled together. In the first embodiment (Figure 6), the inner tube portion is configured to have an approximately cylindrical shape when the pair of split assemblies 5 are closely assembled, and in the second embodiment (Figure 15), it is configured to have a tubular shape with an inner surface having a circular cross-sectional shape and an outer surface having a non-circular cross-sectional shape, but it may be configured to have any tubular shape when the pair of split assemblies 5 are closely assembled.

[0028] In the example of each figure, each divided outer cylinder portion 25D, each divided inner cylinder member 3D, and each divided main body rubber member 4D constitutes approximately half the circumference of the outer cylinder portion 25, the inner cylinder portion 3, and the main body rubber portion 4, respectively, and thus each has an approximately semi-cylindrical shape. However, the first divided outer cylinder portion 25D1, the first divided inner cylinder member 3D1, and the first divided main body rubber member 4D1 may constitute a portion corresponding to any angle range in the outer cylinder portion 25, the inner cylinder portion 3, and the main body rubber portion 4, respectively, and in that case, the second divided outer cylinder portion 25D2, the second divided inner cylinder member 3D2, and the second divided main body rubber member 4D2 constitute a portion corresponding to the remaining angle range in the outer cylinder portion 25, the inner cylinder portion 3, and the main body rubber portion 4, respectively. Furthermore, it is preferable that the angular ranges over which each of the first divided outer tube portion 25D1, the first divided inner tube member 3D1, and the first divided main body rubber member 4D1 extend (approximately 180° in the examples of each figure) are approximately the same, and that the angular ranges over which each of the second divided outer tube portion 25D2, the second divided inner tube member 3D2, and the second divided main body rubber member 4D2 extend (approximately 180° in the examples of each figure) are approximately the same.

[0029] In the example of each figure, the first divided outer cylinder portion 25D1, the first divided inner cylinder member 3D1, and the first divided main body rubber member 4D1 are located on the first vertical side VD1 relative to the second divided outer cylinder portion 25D2, the second divided inner cylinder member 3D2, and the second divided main body rubber member 4D2 (Figs. 1 and 10). When viewed in a cross section perpendicular to the axis (Figs. 1 and 10), the first divided outer cylinder portion 25D1, the first divided inner cylinder member 3D1, and the first divided main body rubber member 4D1 each have a shape curved convexly toward the first vertical side VD1, and the second divided outer cylinder portion 25D2, the second divided inner cylinder member 3D2, and the second divided main body rubber member 4D2 each have a shape curved convexly toward the second vertical side VD2.

[0030] The main rubber portion 4 is made of rubber. In each divided assembly 5, a part or all of the outer peripheral surface of the divided main body rubber member 4D is joined to the inner peripheral surface of the divided outer cylinder portion 25D. Also, in each divided assembly 5, a part or all of the inner peripheral surface of the divided main body rubber member 4D is joined to the outer peripheral surface of the divided inner cylinder member 3D. The joining between the main body rubber portion 4 and the outer tube portion 25 (and thus between the split main body rubber member 4D and the split outer tube portion 25D), as well as the joining between the main body rubber portion 4 and the inner tube portion 3 (and thus between the split main body rubber member 4D and the split inner tube member 3D) may be achieved by any method, such as, for example, vulcanization bonding and / or bonding via an adhesive.

[0031] The inner cylindrical portion 3 is configured to be joined (fixed) to the rod-shaped member R with the rod-shaped member R extending to the inner peripheral side of the inner cylindrical portion 3 (i.e., inside the central hole of the inner cylindrical portion 3) (Figures 3 to 6, Figures 12 to 15). In the examples of the figures, the inner cylindrical portion 3 is made of a thermoplastic resin (FIGS. 3 to 6, 12 to 15). As a result, the inner cylindrical portion 3 is configured to be joined to the rod-shaped member R by welding (thermal welding). An example of the thermoplastic resin that constitutes the inner cylindrical portion 3 is nylon. However, the inner cylindrical portion 3 may be made of a resin other than a thermoplastic resin and / or a metal. Furthermore, the inner cylindrical portion 3 may be configured to be joined to the rod-shaped member R by a method other than welding (for example, adhesion).

[0032] The bracket portion 2 is made of, for example, metal and / or resin. The pair of split bracket members 2D may be made of the same material or different materials. In the example of each figure, the bracket portion 2 further has fitting portions 2D1a, 2D2a and an attachment portion 2D1b in addition to the outer cylinder portion 25 (FIGS. 1 and 10).

[0033] In the examples of each figure, the mating portions 2D1a, 2D2a of the bracket portion 2 are configured so as to enable a pair of split bracket members 2D of the bracket portion 2 (and thus a pair of split assemblies 5) to be assembled by mating (Figures 1, 6, 10, and 15). The fitting portions 2D1a, 2D2a are composed of a pair of legs 2D1a of the first split bracket member 2D1 and a pair of legs 2D2a of the second split bracket member 2D2. The pair of legs 2D1a of the first split bracket member 2D1 extend from both circumferential ends of the first split outer cylinder portion 25D1 of the first split bracket member 2D1 to the second vertical side VD2. The pair of legs 2D2a of the second split bracket member 2D2 extend from both circumferential ends of the second split outer cylinder portion 25D2 of the second split bracket member 2D2 to the second vertical side VD2. The pair of legs 2D2a of the second split bracket member 2D2 are located inward in the width direction WD than the pair of legs 2D1a of the first split bracket member 2D1.

[0034] The first divided assembly 51 defines an accommodating recess 2D1c configured to be able to accommodate the second divided assembly 52. ​​The accommodating recess 2D1c is open on a second vertical side VD2. In the example of each figure, the accommodating recess 2D1c is defined by inner surfaces in the width direction WD of a pair of legs 2D1a of the first divided bracket member 2D1 and the surfaces on the second vertical side VD2 of the first divided outer cylinder portion 25D1, the first divided inner cylinder member 3D1, and the first divided main body rubber member 4D1. When the second split assembly 52 is accommodated in the accommodating recess 2D1c of the first split assembly 51, it moves relatively within the accommodating recess 2D1c toward the first vertical side VD1, and when the pair of legs 2D2a of the second split bracket member 2D2 reach the back of the accommodating recess 2D1c, they engage with the pair of legs 2D1a of the first split bracket member 2D1 (Figures 3, 6, 12, 15). When the pair of legs 2D2a of the second split bracket member 2D2 are fitted into the pair of legs 2D1a of the first split bracket member 2D1, and the second split assembly 52 is completely accommodated in the accommodation recess 2D1c of the first split assembly 51 (FIGS. 6 and 15), the pair of split assemblies 5 are assembled in close contact with each other (closely assembled state of the pair of split assemblies 5). At this time, the end faces of the second vertical side VD2 of each split assembly 5 are flush with each other.

[0035] The mounting portion 2D1b of the bracket portion 2 is configured to be mounted to a vibration receiving member (for example, a part of a vehicle body) VB (FIGS. 6 and 15). The vibration receiving member VB has, for example, a substantially planar shape. More specifically, in the example of each figure, the first split bracket member 2D1 of the bracket portion 2 has a pair of mounting portions 2D1b on both sides in the width direction WD. The pair of mounting portions 2D1b extend outward in the width direction WD from ends of the pair of legs 2D1a of the first split bracket member 2D1 on the second vertical side VD2. Each mounting portion 2D1b has a fastening hole 2D1h and is configured to be attached to the vibration receiving member VB by fastening or the like through the fastening hole 2D1h with a fastener F such as a bolt.

[0036] 6 and 15, the bush 1 is configured so that the rod-shaped member R extends on the inner periphery of the inner cylinder portion 3, the pair of split assemblies 5 are assembled in close contact with each other (closely assembled state of the pair of split assemblies 5), and the end faces of the second vertical side VD2 of each split assembly 5 (more specifically, in the examples of each figure, the end faces of the second vertical side VD2 of each mounting portion 2D1b, each leg portion 2D1a, each leg portion 2D2a, and the second split outer cylinder portion 25D2) are placed on the vibration receiving member VB, and the bush 1 is configured to be attached to the vibration receiving member VB by fastening or the like via the mounting portion 2D1b of the bracket portion 2. In this manner, when the bush 1 is connected between the rod-shaped member R and the vibration receiving member VB, the bush 1 is configured to absorb the rotational displacement of the rod-shaped member R in the torsion direction and suppress the transmission of vibration between the rod-shaped member R and the vibration receiving member VB by the action of the main rubber portion 4.

[0037] The vibration-proof structure S (FIGS. 6 and 15) includes a bush 1 and a rod-shaped member R extending on the inner periphery side of an inner cylindrical portion 3 of the bush 1. The rod-shaped member R is, for example, a torsion bar of a vehicle, in particular a stabilizer bar. In the vibration-proof structure S, the inner cylindrical portion 3 is joined to the rod-shaped member R. More specifically, in the examples of the figures, in the vibration-proof structure S, the inner cylindrical portion 3 is welded to the rod-shaped member R. However, in the vibration-proof structure S, the inner cylindrical portion 3 may be joined to the rod-shaped member R by a method other than welding (for example, adhesive). The vibration-proof structure S may further include a vibration receiving member (eg, a part of the vehicle body) VB.

[0038] Next, a description will be given of a method for manufacturing an anti-vibration structure in the first and second embodiments. The anti-vibration structure manufacturing method includes a bush manufacturing step, a rod-shaped member arranging step, a rod-shaped member joining step, and a bracket portion mounting step.

[0039] First, in a bushing manufacturing process, a bushing 1 is manufactured (FIGS. 1 to 2, 10 to 11). More specifically, in the first and second embodiments, the bush 1 obtained in the bush manufacturing process is in a state in which a pair of split assemblies 5 are separated from each other. In the bush manufacturing process, each split assembly 5 is manufactured through a vulcanization process. More specifically, for example, for each split assembly 5, in a state in which a split bracket member 2D and a split inner cylinder member 3D prepared in advance are set in a mold, unvulcanized rubber for forming a split main body rubber member 4D is injected into a cavity of the mold in an injection process, and then in a vulcanization process, the unvulcanized rubber is vulcanized and molded to connect the split bracket member 2D and the split inner cylinder member 3D to each other with the split main body rubber member 4D, thereby obtaining a split assembly 5.

[0040] After the bushing manufacturing process, in the rod-shaped member arrangement process, the rod-shaped member R is arranged so that the rod-shaped member R extends on the inner periphery side of the inner cylindrical portion 3 of the bushing 1 (i.e., inside the central hole of the inner cylindrical portion 3) (FIGS. 3 and 12). More specifically, in the first and second embodiments, as illustrated in Fig. 3 and Fig. 12, respectively, a pair of split assemblies 5 are assembled together by sandwiching the rod-shaped member R between a pair of split inner cylinder members 3D. At this time, the second split assembly 52 is inserted into the accommodating recess 2D1c of the first split assembly 51 until the pair of split inner cylinder members 3D come into contact with each other. Here, it is not necessarily necessary to insert the second split assembly 52 into the accommodating recess 2D1c of the first split assembly 51 until the second split assembly 52 is completely accommodated in the accommodating recess 2D1c of the first split assembly 51. Immediately after the rod-shaped member arranging step, the rod-shaped member R extends to the inner peripheral side of the inner cylindrical portion 3 of the bushing 1. At this time, it is preferable that the inner peripheral surface of the inner cylindrical portion 3 of the bushing 1 contacts the outer peripheral surface of the rod-shaped member R.

[0041] After the rod-shaped member arrangement step, in the rod-shaped member joining step, the inner cylindrical portion 3 is joined to the rod-shaped member R with the rod-shaped member R extending on the inner peripheral side of the inner cylindrical portion 3 of the bush 1 (FIGS. 4, 5, 13, and 14). As a result, the inner cylindrical portion 3 is joined to the rod-shaped member R extending on the inner peripheral side of the inner cylindrical portion 3. More specifically, in the first and second embodiments, in the rod-shaped member joining step, the inner cylindrical portion 3 is joined to the rod-shaped member R by welding. As a result, the inner cylindrical portion 3 is in a state of being welded to the rod-shaped member R extending along the inner periphery side of the inner cylindrical portion 3. A specific example of a welding technique is to heat the rod-shaped member R, thereby melting the inner peripheral surface of the inner cylinder portion 3 and welding it to the rod-shaped member R. During this process, it is preferable to apply a load to the second split bracket member 2D2 toward the first vertical side VD1, thereby tightly adhering the inner cylinder portion 3 to the rod-shaped member R. As a method for heating the rod-shaped member R, for example, as illustrated in Figures 4, 5, 13, and 14, a coil K is placed on the outer periphery of the rod-shaped member R, and an electric current is passed through the coil K to heat the rod-shaped member R by electromagnetic induction heating. When arranging the coil K on the outer periphery of the rod-shaped member R, as exemplified in Fig. 4 and Fig. 13, the coil K may be arranged on the outer periphery of a portion of the rod-shaped member R that is located outside the inner cylindrical portion 3 of the bush 1 in the axial direction AD. This allows heat generated in the rod-shaped member R on the inner periphery of the coil K to travel through the rod-shaped member R and reach the inner cylindrical portion 3, thereby melting the inner periphery of the inner cylindrical portion 3. Such an arrangement of the coil K is suitable when the length of the inner cylindrical portion 3 in the axial direction AD is relatively short. Alternatively, when the coil K is disposed on the outer periphery of the rod-shaped member R, as illustrated in Figs. 5 and 14, the coil K may be disposed on the outer periphery of the ends of both sides in the axial direction AD of the inner tube portion 3 of the bush. This allows the inner periphery of the inner tube portion 3 to be melted by heat generated in the rod-shaped member R on the inner periphery of the coil K. Such an arrangement of the coil K is preferable when the length of the inner tube portion 3 in the axial direction AD is relatively long. In this case, as illustrated in the examples of Figs. 5 and 14, it is preferable that the inner tube portion 3 extends axially outwardly from the main rubber portion 4, and the coil K is disposed only on the outer periphery of the portion of the inner tube portion 3 located axially outwardly from the main rubber portion 4. However, in the rod-shaped member joining step, the inner cylindrical portion 3 may be joined to the rod-shaped member R by a method other than welding (for example, adhesion).

[0042] After the rod-shaped member joining step, in a bracket portion mounting step, the bracket portion 2 is mounted to a vibration receiving member (eg, a part of a vehicle body) VB by fastening or the like via the mounting portion 2D1b of the bracket portion 2 (FIGS. 6 and 15). More specifically, in the first and second embodiments, in the bracket portion mounting process, the second split bracket member 2D2 (and thus the second split assembly 52) is pushed toward the first vertical side VD1 and deep into the accommodating recess 2D1c until the pair of split assemblies 5 are in a close-fitting assembled state, and further, with the end faces of the second vertical side VD2 of each split assembly 5 (more specifically, in the examples of each figure, the end faces of the second vertical side VD2 of each mounting portion 2D1b, each leg portion 2D1a, each leg portion 2D2a, and each of the second vertical side VD2 of the second split outer tube portion 25D2) placed on the vibration receiving member VB, the mounting portion 2D1b of the bracket portion 2 is attached to the vibration receiving member VB by fastening or the like.

[0043] In this manner, the vibration-isolating structure S can be obtained.

[0044] As described above, in the first and second embodiments, the inner cylindrical portion 3 of the bushing 1 is made of a thermoplastic resin. This makes it possible to join the inner cylindrical portion 3 of the bushing 1 to the rod-shaped member R by welding. As described above, in the first and second embodiments, in the vibration-proof structure manufacturing method and in the vibration-proof structure S, the inner cylindrical portion 3 is joined to the rod-shaped member R by welding. This makes it possible to join (and thus fix) the inner tube portion 3 and the rod-shaped member R without the need for an adhesive between them, thereby eliminating the need for a bonding process. In this way, by joining the inner peripheral surface of the bushing 1 to the rod-shaped member R by welding, it is possible to simplify the work, shorten the time, and simplify the equipment for joining the bushing 1 to the rod-shaped member R, compared to, for example, joining the inner peripheral surface of the bushing 1 to the rod-shaped member R by adhesion, and thus improve the ease of work when joining the bushing 1 to the rod-shaped member R (and thus the manufacturability of the vibration-proof structure S). However, joining by adhesion requires more steps, is expensive, and takes a long time to dry the adhesive. Furthermore, by joining the inner cylinder 3 to the rod-shaped member R, the gap between the inner cylinder 3 and the rod-shaped member R is sealed, which prevents muddy water, dust, and the like from entering between the inner cylinder 3 and the rod-shaped member R. If muddy water, dust, and the like were to enter between the inner cylinder 3 and the rod-shaped member R, there is a risk that abnormal noise will be generated due to stick-slip, or that wear will occur there, creating a gap and causing abnormal rattling noise. Furthermore, by joining the inner cylinder portion 3 to the rod-shaped member R, it is possible to prevent the bush 1 from slipping relative to the rod-shaped member R. For example, when the bush 1 is connected between a torsion bar as the rod-shaped member R and a vehicle body as the vibration receiving member VB, if the bush 1 is allowed to slide relative to the rod-shaped member R, when a lateral force is applied, the torsion bar R may slide laterally relative to the vehicle body VB and may interfere with other components.

[0045] As described above, in the first and second embodiments, the bush 1 is divided into a pair of split assemblies 5, and each split assembly 5 includes a split bracket member 2D having a split outer cylinder portion 25D, a split inner cylinder member 3D, and a split main body rubber member 4D. With this configuration, in the rod-shaped member arrangement step, the pair of split assemblies 5 are simply assembled together so that the rod-shaped member R is sandwiched between the pair of split inner cylinder members 3D, and the rod-shaped member R can be easily arranged on the inner periphery side of the inner cylinder portion 3 of the bush 1. This improves the ease of construction when joining the bush 1 to the rod-shaped member R (and thus the manufacturability of the vibration-proof structure S).

[0046] As described above, in the rod-shaped member joining process, when the coil K is placed on the outer periphery of the rod-shaped member R and the rod-shaped member R is heated by electromagnetic induction heating to melt the inner surface of the inner tube portion 3 and weld it to the rod-shaped member R (Figures 4 to 5, 13 to 14), it is particularly easy to simplify the work, shorten the time, and simplify the equipment, and thus the ease of work when joining the bush 1 to the rod-shaped member R (and thus the manufacturability of the vibration-proof structure S) can be further improved. However, in the rod-shaped member joining step, the inner cylindrical portion 3 may be joined to the rod-shaped member R by welding using a method different from the above.

[0047] In each of the examples described in this specification, the method for manufacturing an anti-vibration structure may further include a rod-shaped member processing step at any timing before the rod-shaped member arranging step. In the rod-shaped member processing step, at least a part of the outer circumferential surface of the rod-shaped member R that will come into contact with the inner tube portion 3 is subjected to a surface processing treatment using a laser or the like to form a rough surface portion RG (shown by dot hatching in Figs. 4 to 5 and Figs. 13 to 14) having a plurality of minute recesses. As a result, the outer circumferential surface of the rod-shaped member R has a rough surface portion RG having a plurality of recesses. The rough surface portion RG has a rougher surface roughness than other parts of the outer circumferential surface of the rod-shaped member R. Due to the presence of the rough surface portion RG, in the subsequent rod-shaped member joining step, the molten resin of the inner tube portion 3 can penetrate into the plurality of recesses in the rough surface portion RG and then harden by cooling, and the anchor effect makes it possible to more reliably join the inner tube portion 3 and the rod-shaped member R. That is, in this case, the inner tube portion 3 is easily welded to the outer circumferential surface of the rod-shaped member R, particularly to the rough surface portion RG. As the above surface processing treatment, for example, the treatment described in Japanese Patent No. 6489908 may be adopted. However, the bar-shaped member processing step (and thus the rough surface portion RG) is not essential.

[0048] In each example described in this specification, the main rubber part 4 may be in a compressed state when the pair of split assemblies 5 are closely assembled (FIGS. 6 and 15). In this case, an initial strain is applied to the main rubber part 4, thereby improving durability. In the examples of each figure, when a pair of split assemblies 5 are separated from each other (Figures 1 and 10), each split assembly 5 is positioned such that the central axis O3 of the split inner tube member 3D and the central axis O25 of the split outer tube portion 25D are located at different positions in the vertical direction VD. As a result, when the pair of split assemblies 5 are in a close-fitting assembled state (Figures 6 and 15) and the central axis O3 of the split inner tube member 3D and the central axis O25 of the split outer tube portion 25D coincide with each other, the main rubber portion 4 is compressed. However, this configuration is not essential.

[0049] In each example described in this specification, as in the examples of each figure, in each split assembly 5, the outer surface of the split inner tube member 3D has, when viewed in a cross section perpendicular to the axial direction, a pair of first joint portions 311 (hereinafter also simply referred to as "join portions (311)") and a first non-join portion 312 (hereinafter also simply referred to as "non-join portion (312)") in at least a portion of the axial direction AD of the split inner tube member 3D (i.e., at each axial position in at least a portion of the axial direction AD of the split inner tube member 3D) (Figures 1, 3, 6, 10, 12, 15). The pair of first joint portions 311 are located at both circumferential end portions of the split inner cylinder member 3D and are respectively joined to the split main body rubber member 4D. It is preferable that the pair of first joint portions 311 extend over the entire length of the split inner cylinder member 3D in the axial direction AD. The first non-joined portion 312 extends between the pair of first joint portions 311 in the circumferential direction, and is not joined to the divided main body rubber member 4D. The first non-bonded portion 312 may be in contact with the divided main body rubber member 4D as in the examples shown in Figures 1, 3, 10, and 12. In this case, the gap G between the first non-bonded portion 312 and the divided main body rubber member 4D is in a substantially or completely collapsed state. In this specification, "in contact" with respect to the relationship between the inner tube portion 3 and the main rubber portion 4 does not mean limited to the case where the inner tube portion 3 and the main rubber portion 4 are in direct contact with each other with nothing interposed therebetween, but also includes the case where a lubricant 6 is interposed between the inner tube portion 3 and the main rubber portion 4 as described below (Figure 17), but excludes the case where a member or space other than the lubricant 6 is interposed between the inner tube portion 3 and the main rubber portion 4. Alternatively, the first non-jointed portion 312 may not be in contact with the divided main body rubber member 4D, and a gap G that actually forms a space may exist between the divided main body rubber member 4D and the first non-jointed portion 312. In each split assembly 5, it is preferable that the outer circumferential surface of the split inner cylinder member 3D has the above-mentioned pair of first joint portions 311 and first non-joint portions 312 only in the center of the split inner cylinder member 3D in the axial direction AD when viewed in cross section perpendicular to the axis, and for example, it is preferable that the outer circumferential surface of the split inner cylinder member 3D has the above-mentioned pair of first joint portions 311 and first non-joint portions 312 only in a portion along a second non-joint portion 322 (FIGS. 4 to 5, 16) described below of the split inner cylinder member 3D in the axial direction AD when viewed in cross section perpendicular to the axis. In each split assembly 5, it is preferable that the outer circumferential surface of the split inner cylinder member 3D has only joint portions 321 (FIGS. 4 to 5, 16) over the entire circumferential length at the ends on both sides of the axial direction AD of the split inner cylinder member 3D when viewed in cross section perpendicular to the axis.

[0050] As described above, in each split assembly 5, the outer surface of the split inner tube member 3D, in at least a portion of the axial direction AD of the split inner tube member 3D, has a pair of first joint portions 311 on both circumferential sides and a first non-joint portion 312 therebetween, when viewed in a cross section perpendicular to the axial direction (Figures 1, 3, 6, 10, 12, 15), which has the following advantages. First, when the split inner cylinder member 3D (and thus the inner cylinder portion 3) is displaced in a torsional direction (the direction in which the inner cylinder portion 3 rotates in the circumferential direction relative to the outer cylinder portion 25) or a twisting direction (the direction in which the central axis O3 of the inner cylinder portion 3 tilts relative to the central axis O25 of the outer cylinder portion 25) relative to the split outer cylinder portion 25D (and thus the outer cylinder portion 25), the split inner cylinder member 3D is fixed to the split main body rubber member 4D at a pair of first joint portions 311 on both sides in the circumferential direction, but can slide on the split main body rubber member 4D at the first non-joint portion 312 therebetween. Therefore, while displacing in the torsional direction or twisting direction, the portion of the split main body rubber member 4D near the pair of first joint portions 311 contributes to the spring rigidity, but the portion of the split main body rubber member 4D near the first non-joint portion 312 contributes little or nothing to the spring rigidity. Therefore, compared to a case where the split main body rubber member 4D is bonded to the split inner cylinder member 3D over the entire surface of the split main body rubber member 4D, the area of ​​the portion where the split main body rubber member 4D is bonded to the split inner cylinder member 3D is smaller, so that the rigidity in the torsional and prying directions can be reduced accordingly, and thus the split inner cylinder member 3D (and thus the inner cylinder portion 3) can more easily swing in the torsional and prying directions relative to the split outer cylinder portion 25D (and thus the outer cylinder portion 25). This improves the performance as a vibration-proof structure for a vehicle. Furthermore, since the presence of the first non-jointed portion 312 does not affect the displacement in the axial direction, the divided main body rubber member 4D (and thus the main body rubber portion 4) can exhibit high spring rigidity equal to or greater than that of the conventional structure when the divided inner cylinder member 3D (and thus the inner cylinder portion 3) is displaced in the axial direction relative to the divided outer cylinder portion 25D (and thus the outer cylinder portion 25). This in turn improves the performance as a vibration-proof structure for a vehicle. Furthermore, the gap G between the split main body rubber member 4D and the first non-joint portion 312 of the split inner cylinder member 3D is sealed by a pair of first joint portions 311 on both circumferential sides thereof. This makes it possible to prevent dust and the like from entering this gap G through the mating surfaces between the pair of split assemblies 5, and thus to prevent a decrease in the sliding property between the split main body rubber member 4D and the split inner cylinder member 3D therein. Furthermore, if the lubricant 6 is filled in this gap G as described below (FIG. 17), it is possible to prevent the lubricant 6 from leaking out through the mating surfaces between the pair of split assemblies 5.

[0051] In each example described in this specification, as in the examples of each figure, in each split assembly 5, the outer peripheral surface of the split inner tube member 3D may have a pair of second joint portions 321 (hereinafter also simply referred to as "join portions (321)") and a second non-join portion 322 (hereinafter also simply referred to as "non-join portion (322)") in at least a portion of the circumferential direction of the split inner tube member 3D (i.e., at each circumferential position in at least a portion of the circumferential direction of the split inner tube member 3D) when viewed in axial cross section (Figures 2, 4 to 5, 11, 16, 17). The pair of second joint portions 321 are located at both ends of the split inner cylinder member 3D in the axial direction AD, and are respectively joined to the split main body rubber member 4D. It is preferable that the pair of second joint portions 321 extend over the entire circumferential length of the split inner cylinder member 3D. The second non-joined portion 322 extends between the pair of second joint portions 321 in the axial direction, and is not joined to the divided main body rubber member 4D. The second non-joined portion 322 may be in contact with the divided main body rubber member 4D as in the examples shown in Figures 2, 4 to 5, 11, 16, and 17. In this case, the gap G between the second non-joined portion 322 and the divided main body rubber member 4D is in a substantially or completely collapsed state. Alternatively, the second non-jointed portion 322 may not be in contact with the divided main body rubber member 4D, and a gap G that actually forms a space may exist between the divided main body rubber member 4D and the second non-jointed portion 322. In each split assembly 5, it is preferable that the outer circumferential surface of the split inner cylinder member 3D has the above-mentioned pair of second joint portions 321 and second non-joint portions 322 only at the circumferential center of the split inner cylinder member 3D when viewed in axial cross section, and for example, it is preferable that the outer circumferential surface of the split inner cylinder member 3D has the above-mentioned pair of second joint portions 321 and second non-joint portions 322 only at a portion along the above-mentioned first non-joint portion 312 (FIGS. 6, 15) of the split inner cylinder member 3D when viewed in axial cross section. In each split assembly 5, it is preferable that the outer circumferential surface of the split inner cylinder member 3D has only joint portions 311 (FIGS. 6, 15) over the entire axial length at both circumferential ends of the split inner cylinder member 3D when viewed in axial cross section.

[0052] As described above, in each split assembly 5, when the outer peripheral surface of the split inner tube member 3D has, in at least a portion of the circumferential direction of the split inner tube member 3D, a pair of second joint portions 321 on both axial sides and a second non-joint portion 322 therebetween when viewed in axial cross section (Figures 2, 4 to 5, 11, 16, and 17), the following advantages are obtained. First, when the split inner cylinder member 3D (and thus the inner cylinder portion 3) is displaced in a torsional or twisting direction relative to the split outer cylinder portion 25D (and thus the outer cylinder portion 25), the split inner cylinder member 3D is fixed to the split main body rubber member 4D at a pair of second joint portions 321 on both sides in the axial direction, but can slide on the split main body rubber member 4D at the second non-joint portion 322 therebetween. Therefore, during displacement in the torsional or twisting direction, the portion of the split main body rubber member 4D in the vicinity of the pair of second joint portions 321 contributes to the spring rigidity, but the portion of the split main body rubber member 4D in the vicinity of the second non-joint portion 322 contributes little or nothing to the spring rigidity. Therefore, compared to a case where the split main body rubber member 4D is bonded to the split inner cylinder member 3D over the entire surface of the split main body rubber member 4D, the area of ​​the portion where the split main body rubber member 4D is bonded to the split inner cylinder member 3D is smaller, so that the rigidity in the torsional and prying directions can be reduced accordingly, and thus the split inner cylinder member 3D (and thus the inner cylinder portion 3) can more easily swing in the torsional and prying directions relative to the split outer cylinder portion 25D (and thus the outer cylinder portion 25). This improves the performance as a vibration-proof structure for a vehicle. Furthermore, since the presence of the second non-jointed portion 322 does not affect the displacement in the axial direction, the divided main body rubber member 4D (and thus the main body rubber portion 4) can exhibit high spring rigidity equal to or greater than that of the conventional structure when the divided inner cylinder member 3D (and thus the inner cylinder portion 3) is displaced in the axial direction relative to the divided outer cylinder portion 25D (and thus the outer cylinder portion 25). This in turn improves the performance as a vibration-proof structure for a vehicle. Furthermore, the gap G between the split main body rubber member 4D and the second non-joint portion 322 of the split inner cylinder member 3D is sealed by a pair of second joint portions 321 on both axial sides thereof. This prevents dust and other particles from entering the gap G from both axial sides, thereby preventing a decrease in the sliding properties between the split main body rubber member 4D and the split inner cylinder member 3D. Furthermore, if the gap G is filled with lubricant 6 as described below (FIG. 17), the lubricant 6 can be prevented from leaking out from both axial sides.

[0053] As described above, the bush 1 in the example of each figure has parts (first non-jointed part 312, second non-jointed part 322) where the inner tube part 3 can slide against the main rubber part 4, and therefore can be said to be a so-called "sliding type bush."

[0054] In the bush manufacturing process, it is preferable that the bonded portions 311, 321 and the non-bonded portions 312, 322 are formed in a vulcanization process. One method for forming the joints 311, 321 and the non-joints 312, 322 in the vulcanization process is as follows. First, in a surface processing step before the vulcanization step, the portions of the outer circumferential surface of the split inner cylinder member 3D that will become the joints 311, 321 are subjected to a surface processing treatment using a laser or the like, thereby forming a plurality of minute recesses in the corresponding portions of the split inner cylinder member 3D. The portions of the outer circumferential surface of the split inner cylinder member 3D that will become the non-joints 312, 322 are not subjected to a surface processing treatment. Then, in an injection step, unvulcanized rubber for forming the split main body rubber member 4D is injected into a mold in which the split bracket member 2D and the split inner cylinder member 3D are set, and then, in the vulcanization step, the split assembly 5 is vulcanized and molded by the mold. In this case, during the vulcanization process, the divided main body rubber member 4D enters into a plurality of minute recesses in the surface-treated portion of the outer circumferential surface of the divided inner tube member 3D, and is joined to the portion by the anchor effect, forming joints 311, 321, and is not joined to the portion of the outer circumferential surface of the divided inner tube member 3D that has not been subjected to the surface treatment, forming non-joined portions 312, 322. Note that, for example, the surface treatment described in JP 2020-116862 A and JP 6489908 A may be adopted as the surface treatment. Another method for forming the joints 311, 321 and the non-joints 312, 322 in the vulcanization process is as follows. First, in an adhesive sheet attachment process prior to the vulcanization process, an adhesive sheet is attached to the portions of the outer circumferential surface of the split inner cylinder member 3D that will become the joints 311, 321. At this time, the adhesive sheet is not attached to the portions of the outer circumferential surface of the split inner cylinder member 3D that will become the non-joints 312, 322. Then, in an injection process, unvulcanized rubber for forming the split main body rubber member 4D is injected into a mold in which the split bracket member 2D and the split inner cylinder member 3D are set, and then, in the vulcanization process, the split assembly 5 is vulcanized and molded by the mold. In this case, during the vulcanization process, the divided main body rubber member 4D is bonded to the portion of the outer circumferential surface of the divided inner cylinder member 3D to which the adhesive sheet is attached, forming bonded portions 311, 321, and is not bonded to the portion of the outer circumferential surface of the divided inner cylinder member 3D to which the adhesive sheet is not attached, forming non-bonded portions 312, 322. Note that, for example, the adhesive sheet described in Japanese Patent No. 4681634 may be used as this adhesive sheet. Another method for forming the joints 311, 321 and the non-joints 312, 322 in the vulcanization process is as follows. First, in an adhesive application process before the vulcanization process, the portions of the outer circumferential surface of the split inner cylinder member 3D that will become the non-joints 312, 322 are masked, and then adhesive is applied to the portions of the outer circumferential surface of the split inner cylinder member 3D that will become the joints 311, 321. This prevents adhesive from being applied to the portions of the outer circumferential surface of the split inner cylinder member 3D that will become the non-joints 312, 322. Thereafter, the masking is removed. Then, in an injection process, unvulcanized rubber for forming the split main body rubber member 4D is injected into a mold in which the split bracket member 2D and the split inner cylinder member 3D are set, and then, in a vulcanization process, the split assembly 5 is vulcanized and molded by the mold. In this case, during the vulcanization process, the split main body rubber member 4D is joined to the portion of the outer surface of the split inner tube member 3D where adhesive has been applied, forming joints 311, 321, and is not joined to the portion of the outer surface of the split inner tube member 3D that has been masked (i.e., where adhesive has not been applied), forming non-jointed portions 312, 322. However, methods for forming the bonded portions 311, 321 and the non-bonded portions 312, 322 may be other than those described above.

[0055] A lubricant 6 may be interposed between the divided main body rubber member 4D and the non-jointed portions 312, 322 of the divided inner cylinder member 3D, as shown in Fig. 17. In this case, the lubricant 6 is filled in the gap G between the divided main body rubber member 4D and the non-jointed portions 312, 322 of the divided inner cylinder member 3D. 17, this gap G is shown in an exaggerated manner, but in reality, this gap G may be almost or completely collapsed. Therefore, the layer thickness of the lubricant 6 may actually be very thin. In this case, the divided main body rubber member 4D and the non-jointed portions 312, 322 of the divided inner cylinder member 3D come into contact with each other via the lubricant 6. The lubricant 6 is, for example, a lubricating oil. By interposing the lubricant 6 between the divided main body rubber member 4D and the non-jointed portions 312, 322 of the divided inner cylinder member 3D, the frictional resistance between the divided main body rubber member 4D and the non-jointed portions 312, 322 of the divided inner cylinder member 3D can be reduced, and therefore the non-jointed portions 312, 322 of the divided inner cylinder member 3D can slide more easily against the divided main body rubber member 4D. This makes it easier for the inner cylinder portion 3 to swing in the twisting and twisting directions. However, as shown in Figs. 15 and 16, the lubricant 6 does not have to be interposed between the divided main body rubber member 4D and the non-jointed portions 312, 322 of the divided inner cylinder member 3D.

[0056] When lubricant 6 is interposed between non-jointed portions 312, 322 of split inner cylinder member 3D and split main body rubber member 4D (FIG. 17), it is preferable to carry out a lubricant injection step after the vulcanization step in the bushing manufacturing process. When performing the lubricant injection process, injection holes H are formed in each split assembly 5 of the bush 1 in advance. The injection holes H communicate the gap G between the non-jointed portions 312, 322 of the split inner cylinder member 3D and the split main body rubber member 4D with the outside of the split assembly 5. As in the example of FIG. 17, the injection holes H may pass through the split outer cylinder portion 25D and the split main body rubber member 4D of the split assembly 5 between the gap G and the outside of the split assembly 5. In this case, any method may be used to form the injection holes H in advance. For example, a through hole may be formed in the corresponding position of the split outer cylinder portion 25D in advance, and a protrusion for forming the injection holes H may be provided on a mold used in the injection process and the vulcanization process. In the lubricant injection step, lubricant 6 is injected from the outside through injection hole H into gap G between non-jointed portions 312, 322 of split inner cylinder member 3D and split main body rubber member 4D.

[0057] In the bushing manufacturing process, when the lubricant injection step is performed as described above, a plug insertion step may be performed after the lubricant injection step. When performing the plug insertion step, as shown in Fig. 17, the plug P is inserted into the injection hole H from the outside of the split assembly 5 to close the injection hole H. This makes it possible to prevent the lubricant 6 from leaking out to the outside.

[0058] In each example described in this specification, as in the second embodiment shown in Figures 10 to 17, in each split assembly 5, the outer circumferential surface of the split inner cylinder member 3D may have a first protruding portion 33 (protruding portion) that protrudes toward the outer circumferential side at the center in the axial direction of the split inner cylinder member 3D when viewed in an axial cross section (Figure 16) in at least a part of the circumferential direction of the split inner cylinder member 3D (i.e., at each circumferential position in at least a part of the circumferential direction of the split inner cylinder member 3D). In this case, the part of the inner circumferential surface of the split main body rubber member 4D that comes into contact with the first protruding portion 33 of the split inner cylinder member 3D forms a concave shape recessed toward the outer circumferential side to fit the first protruding portion 33. When the outer peripheral surface of the split inner tube member 3D has the first protrusion 33 (Figure 16), the thickness of the split main body rubber member 4D located on the outer peripheral side of the first protrusion 33 is thinner than when the split inner tube member 3D does not have the first protrusion 33 (see, for example, Figures 4 to 5). As a result, the split main body rubber member 4D can exhibit higher spring rigidity against relative displacement perpendicular to the axis of the split inner tube member 3D. Furthermore, when the outer peripheral surface of the split inner tube member 3D has the first protrusion 33 (Figure 16), unlike when the first protrusion 33 is not present (see, for example, Figures 4 to 5), the first protrusion 33 has side surfaces on both axial sides, which improves durability and makes it easier to suppress axial displacement of the split inner tube member 3D, thereby suppressing axial movement of the rod-shaped member R. In each split assembly 5, the outer peripheral surface of the split inner tube member 3D may extend in an approximately linear manner along the axial direction on both sides of the axial direction AD relative to the first protrusion 33, when viewed in an axial cross section (Figure 16), in at least a portion of the circumferential direction of the split inner tube member 3D. In each split assembly 5, the outer circumferential surface of the split inner cylinder member 3D may have the first protruding portion 33 at the axial center of the split inner cylinder member 3D only at the circumferential center of the split inner cylinder member 3D when viewed in axial cross section, for example, the first protruding portion 33 may be at the axial center of the split inner cylinder member 3D only in a portion along the first non-joint portion 312 (FIG. 15) of the split inner cylinder member 3D in the circumferential direction when viewed in axial cross section. In each split assembly 5, the outer circumferential surface of the split inner cylinder member 3D may not have the first protruding portion 33 at both circumferential ends of the split inner cylinder member 3D when viewed in axial cross section, and may extend approximately linearly along the axial direction over the entire axial length.

[0059] In each split assembly 5, as in the example of Figure 16, when viewed in axial cross section, it is preferable that a pair of second joint portions 321 constitute at least a portion of the outer surface of the split inner tube member 3D on both sides in the axial direction AD relative to the first protrusion portion 33, and that the second non-joint portion 322 constitutes at least a portion (preferably the entirety) of the first protrusion portion 33 of the split inner tube member 3D. In this case, when the split inner cylinder member 3D is displaced in the prying direction, the second non-jointed portion 322 including the first protruding portion 33 of the split inner cylinder member 3D slides more easily against the split main body rubber member 4D. Therefore, the spring rigidity against displacement in the prying direction can be further reduced.

[0060] In each divided assembly 5, the protruding shape of the first protruding portion 33 when viewed in an axial cross section may be any shape as long as it protrudes toward the outer periphery. As illustrated in FIG. 16, in each split assembly 5, when viewed in axial cross section, the first protruding portion 33 may have a recessed portion 33a recessed toward the inner periphery at its protruding end surface toward the outer periphery. The radial depth of the recessed portion 33a is smaller than the radial height of the first protruding portion 33. In this case, the portion of the inner periphery of the split main body rubber member 4D that contacts the recessed portion 33a of the first protruding portion 33 of the split inner tube member 3D forms a convex shape protruding toward the inner periphery to fit the recessed portion 33a. With this configuration, the axial displacement of the split inner tube member 3D is further suppressed, and thus the axial movement of the rod-shaped member R can be further suppressed. 16, in each split assembly 5, the inner circumferential surface of the split outer cylinder portion 25D may have a protrusion 25a that protrudes inward toward the recessed portion 33a on the outer circumferential side of the recessed portion 33a of the first protruding portion 33 of the split inner cylinder member 3D when viewed in axial cross section. With this configuration, the axial displacement of the split inner cylinder member 3D can be further suppressed, and thus the axial movement of the rod-shaped member R can be further suppressed.

[0061] In each example described in this specification, as in the second embodiment shown in Figures 10 to 17, in each split assembly 5, the outer circumferential surface of the split inner cylinder member 3D may have a second protruding portion 34 (protruding portion) protruding toward the outer circumferential side at the circumferential center of the split inner cylinder member 3D in at least a part of the axial direction of the split inner cylinder member 3D (i.e., at each axial position in at least a part of the axial direction AD of the split inner cylinder member 3D) when viewed in a cross section perpendicular to the axis (Figure 15). In this case, the part of the inner circumferential surface of the split main body rubber member 4D that comes into contact with the second protruding portion 34 of the split inner cylinder member 3D forms a concave shape recessed toward the outer circumferential side to fit the second protruding portion 34. When the outer peripheral surface of the split inner tube member 3D has the second protrusion 34 (Figure 15), the thickness of the split main body rubber member 4D located on the outer peripheral side of the second protrusion 34 is thinner than when the split inner tube member 3D does not have the second protrusion 34 (see, for example, Figure 6), and therefore the split main body rubber member 4D can exhibit higher spring rigidity against relative displacement perpendicular to the axis of the split inner tube member 3D. In each split assembly 5, the outer peripheral surface of the split inner tube member 3D may extend circumferentially on both circumferential sides of the second protrusion 34 when viewed in a cross section perpendicular to the axis (Figure 16) in at least a portion of the circumferential direction of the split inner tube member 3D. In each split assembly 5, the outer circumferential surface of the split inner cylinder member 3D may have the second protruding portion 34 at the axial center of the split inner cylinder member 3D only at the circumferential center of the split inner cylinder member 3D when viewed in cross section perpendicular to the axis, for example, the outer circumferential surface of the split inner cylinder member 3D may have the second protruding portion 34 at the axial center of the split inner cylinder member 3D only in a portion along the second non-joint portion 322 (FIG. 16) of the split inner cylinder member 3D in the axial direction when viewed in cross section perpendicular to the axis. In each split assembly 5, the outer circumferential surface of the split inner cylinder member 3D may not have the second protruding portion 34 at both axial ends of the split inner cylinder member 3D when viewed in cross section perpendicular to the axis, and may extend along the circumferential direction over the entire circumferential length.

[0062] In each split assembly 5, as in the example of Figure 15, when viewed in a cross section perpendicular to the axis, it is preferable that a pair of joint portions 311 constitute at least a portion of the outer peripheral surface of the split inner tube member 3D on both circumferential sides of the second protrusion portion 34, and that the non-joint portion 312 constitutes at least a portion (preferably the entirety) of the second protrusion portion 34 of the split inner tube member 3D. In this case, when the split inner cylinder member 3D is displaced in the prying direction, the non-jointed portion 312 including the second protruding portion 34 of the split inner cylinder member 3D slides more easily against the split main body rubber member 4D. Therefore, the spring rigidity against displacement in the prying direction can be further reduced. [Industrial Applicability]

[0063] The bushing, vibration-proof structure, and vibration-proof structure manufacturing method of the present invention are suitable for use in the connecting portion between a rod-shaped member in a vehicle (e.g., a torsion bar of the vehicle, particularly a stabilizer bar) and a vibration-receiving member (e.g., a part of the vehicle body). [Explanation of symbols]

[0064] S: Anti-vibration structure, 1: Bush, 2: bracket portion, 2D: split bracket member, 2D1: first split bracket member, 2D1a: leg portion (fitting portion), 2D1b: mounting portion, 2D1h: fastening hole, 2D1c: accommodation recess, 2D2: second split bracket member, 2D2a: leg portion (fitting portion), 25: outer cylinder portion, 25D: split outer cylinder portion, 25D1: first split outer cylinder portion, 25D2: second split outer cylinder portion, 25a: protrusion portion, 3: inner cylinder portion, 3D: divided inner cylinder member, 3D1: first divided inner cylinder member, 3D2: second divided inner cylinder member, 311: first joint portion (joining portion), 312: first non-joining portion (non-joining portion), 321: second joint portion (joining portion), 322: second non-joining portion (non-joining portion), 33: first protruding portion (protruding portion), 33a: recessed portion, 34: second protruding portion (protruding portion), 4: main body rubber part; 4D: divided main body rubber member; 4D1: first divided main body rubber member; 4D2: second divided main body rubber member; 5: Divided assembly, 51: First divided assembly, 52: Second divided assembly, 6: Lubricants, G: Gap, H: injection hole, P: Plug, F: fastener, O25: central axis of the outer cylinder (central axis of the divided outer cylinder), O3: central axis of the inner cylinder (central axis of the divided inner cylinder member, central axis of the bush, central axis of the vibration-proof structure), R: Rod-shaped member, RG: Rough surface part, AD: Axial direction, VD: vertical direction, VD1: first vertical side, VD2: second vertical side, WD: Width direction, K: Coil, VB: Vibration receiving material

Claims

1. A bracket portion having an outer cylinder portion; An inner cylinder portion; a main rubber portion that connects the outer cylinder portion and the inner cylinder portion to each other; A bushing comprising: The bushing includes a pair of split assemblies; Each of the split assemblies includes: a split bracket member including a split outer cylinder portion that constitutes a part of the bracket portion and constitutes a circumferential part of the outer cylinder portion; A divided inner cylinder member that constitutes a circumferential portion of the inner cylinder portion; a split main body rubber member that constitutes a circumferential portion of the main body rubber portion and connects the split outer cylinder portion and the split inner cylinder member of the split bracket member; Equipped with In each of the split assemblies, the outer circumferential surface of the split inner cylinder member has, when viewed in a cross section perpendicular to the axis, at least a portion of the axial direction of the split inner cylinder member, a pair of first joint portions joined to the divided main body rubber member at both circumferential end portions of the divided inner cylinder member; a first non-joined portion that extends between the pair of first joined portions in the circumferential direction and is not joined to the divided main body rubber member; Bush has.

2. In each of the split assemblies, the outer circumferential surface of the split inner cylinder member has, when viewed in an axial cross section, at least a portion of the circumferential direction of the split inner cylinder member. a pair of second joint portions joined to the divided main body rubber member at both axial ends of the divided inner cylinder member; a second non-joined portion that extends between the pair of second joined portions in the axial direction and is not joined to the divided main body rubber member; The bushing of claim 1 , comprising:

3. The bushing described in claim 1, wherein in each of the split assemblies, the outer peripheral surface of the split inner tube member has a protrusion that protrudes toward the outer peripheral side at the axial center of the split inner tube member in at least a portion of the circumferential direction of the split inner tube member when viewed in axial cross section.

4. A bush according to any one of claims 1 to 3; a rod-shaped member extending along an inner circumferential side of the inner cylindrical portion of the bush; A vibration-proof structure comprising: The inner cylindrical portion is joined to the rod-shaped member,

5. A method for manufacturing the vibration-isolating structure according to claim 4, comprising the steps of: a bushing manufacturing process for manufacturing the bushing; a rod-shaped member joining process for joining the inner cylindrical portion to the rod-shaped member in a state in which the rod-shaped member is extended to an inner peripheral side of the inner cylindrical portion of the bush; A method for manufacturing a vibration-proof structure comprising the steps of:

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