JP2024154354A - Anti-vibration structure, strut mount, and method for manufacturing anti-vibration structure - Google Patents

Abstract

To provide a vibration control structure and a strut mount capable of reducing stiffness in a twisting direction, and a method of manufacturing the vibration control structure that can obtain a vibration control structure capable of reducing the stiffness in the twisting direction.SOLUTION: A vibration control structure 1 is equipped with an inner cylinder 2, an outer cylinder 3, and a body rubber 4 coupling the inner cylinder and the outer cylinder. An inner peripheral surface of the body rubber has a pair of joint parts 41 jointed over the whole circumference to an outer peripheral surface and/or an axial direction end surface of the inner cylinder on both sides in an axis direction, and a non-joint portion 42 that extends between the pair of the joint portions, and is not joined but contacted to the inner cylinder.SELECTED DRAWING: Figure 1

Description

This invention relates to a vibration-proof structure, a strut mount, and a method for manufacturing a vibration-proof structure.

Conventionally, there has been a vibration-proof structure that includes an inner tube, an outer tube, and a main rubber body that connects the inner tube and the outer tube together (for example, Patent Document 1).

JP 2015-209145 A

However, in conventional vibration-proof structures, the main rubber is bonded to both the inner and outer tubes over the entire surface of the main rubber, which means that the rigidity in the torsional direction is high, making it difficult for the inner tube to swing in the torsional direction relative to the outer tube.

The object of this invention is to provide an anti-vibration structure and strut mount 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.

[1] an inner cylinder;
An outer cylinder,
a main body rubber that connects the inner cylinder and the outer cylinder to each other;
A vibration-proof structure comprising:
The inner circumferential surface of the main rubber is
A pair of joints joined to an outer peripheral surface and/or an axial end surface of the inner cylinder over the entire circumference on both sides in the axial direction;
a non-jointed portion extending between the pair of jointed portions and contacting the inner cylinder without being joined thereto;
It has a vibration-proof structure.
This makes it possible to reduce the rigidity in the torsional direction.

[2] The outer cylinder has a straight portion extending parallel to the axial direction,
The vibration-proof structure described in [1], wherein the straight portion extends at least from the axial center of the vibration-proof structure to the axial position of at least a portion of each of the pair of joints of the main rubber.
This can improve durability.

[3] The vibration-proof structure described in [1] or [2], in which a lubricant is interposed between the inner tube and the non-jointed portion of the main rubber.
In this case, the main body rubber is more likely to slide relative to the inner cylinder.

[4] A vibration-proof structure described in any one of [1] to [3], wherein the outer peripheral surface of the inner tube has a bulge-shaped portion that protrudes toward the outer peripheral side.
In this case, higher spring rigidity can be exerted against displacement in the direction perpendicular to the axis.

[5] The pair of joint portions of the main rubber are joined over an entire circumference to a portion of the outer circumferential surface of the inner tube excluding the bulge-shaped portion and/or to the axial end surface of the inner tube,
The vibration-proof structure described in [4], wherein the non-jointed portion of the main body rubber is not joined to but is in contact with the bulge-shaped portion of the inner tube.
In this case, the spring stiffness against displacement in the prying direction can be further reduced.

[6] The outer cylinder is composed of a plurality of partial outer cylinder members arranged along the circumferential direction and constructed separately from each other,
The vibration-proof structure described in any one of [1] to [5], wherein in a natural state in which no external force is acting on the vibration-proof structure, the multiple partial outer cylinder members are spaced apart from each other in the circumferential direction.

[7] The outer peripheral surface of the inner tube has a pair of circumferential grooves extending in the circumferential direction, the pair of circumferential grooves being axially inward of the pair of joints of the main rubber,
The vibration-proof structure described in any one of [1] to [6], wherein the non-jointed portion of the main body rubber has a pair of protrusions configured to fit into the pair of circumferential grooves.

[8] The vibration-proof structure described in any one of [1] to [7], wherein the vibration-proof structure is configured as a bush used in a link mechanism of a suspension device.

[9] The vibration-proof structure described in any one of [1] to [7], wherein the vibration-proof structure is configured to be provided on a strut mount.

[10] A strut mount comprising the vibration-proof structure according to any one of [1] to [7].
This makes it possible to reduce the rigidity in the torsional direction.

[11] A method for manufacturing a vibration-proof structure, comprising the steps of: manufacturing the vibration-proof structure according to any one of [1] to [7] through a vulcanization step.
This makes it possible to obtain a vibration-proof structure that can reduce the rigidity in the torsional direction.

This invention provides an anti-vibration structure and strut mount 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.

1 is a cross-sectional view illustrating a vibration-proof structure according to a first embodiment of the present invention. 2 is a diagram for explaining a joint portion and a non-joint portion in the inner cylinder of FIG. 1 . 2 is a diagram for explaining an example of performing a lubricant injection process when manufacturing the vibration-proof structure of FIG. 1 . 2 is a diagram for explaining an example of performing a plug insertion process when manufacturing the vibration-proof structure of FIG. 1 . 4 is a diagram for explaining an example in which the injection hole in FIG. 3 is blocked by a narrowing process. 2 is a diagram for explaining the operation of the vibration-proof structure of FIG. 1 when an inner cylinder is displaced by twisting; 2 is a cross-sectional view illustrating a first modified example of the vibration-proof structure of FIG. 1. 1 is a cross-sectional view illustrating a strut mount having a vibration-proof structure according to a second embodiment of the present invention. FIG. 9 is a diagram for explaining a joint portion and a non-joint portion in the inner cylinder of FIG. 8 . 9 is a diagram for explaining an example of performing a lubricant injection step when manufacturing the vibration-proof structure of FIG. 8 . 9 is a diagram for explaining an example of performing a plug insertion process when manufacturing the vibration-proof structure of FIG. 8 . 9 is a diagram for explaining an example of performing a drawing process when manufacturing the vibration-proof structure of FIG. 8 . 9 is a diagram for explaining the operation when an inner cylinder is displaced by twisting in the vibration-proof structure of FIG. 8 . 9 is a diagram for explaining the operation of the vibration-proof structure of FIG. 8 when an inner cylinder is displaced in the axial direction. FIG. 9 is a cross-sectional view that illustrates a modified example of the vibration-proof structure of FIG. 8. 16 is a diagram for explaining a joint portion and a non-joint portion in the inner cylinder of FIG. 15 . 1. FIG. 4 is a cross-sectional view that illustrates a second modified example of the vibration-proof structure of FIG. 18 is a diagram for explaining the operation of the vibration-proof structure of FIG. 17 when the inner cylinder is displaced in a direction perpendicular to the axis. 18 is a diagram for explaining an example in which a bending process is performed after a vulcanization process when manufacturing the vibration-proof structure of FIG. 17. 1. FIG. 4 is a cross-sectional view that illustrates a third modified example of the vibration-proof structure of FIG. 1. FIG. 4 is a side view showing a fourth modified example of the vibration-proof structure of FIG. 1 as viewed from the radially outer side. 22 is a front view showing the vibration-proof structure of FIG. 21 as viewed from one side in the axial direction. FIG. 23 is an AA cross-sectional view that shows the vibration-proof structure of FIG. 22 in a schematic cross-section taken along the line AA of FIG. 22. FIG. 24 is a diagram for explaining the operation of the vibration-proof structure of FIG. 23 when the inner cylinder is displaced in a direction perpendicular to the axis. Figure 25(a) is a side view that shows, in outline, the appearance of one of the partial outer tube members in Figure 21 when viewed from the radial outside, and Figure 25(b) is a front view that shows, in outline, the appearance of the partial outer tube member in Figure 25(a) when viewed from one axial side. Figure 26(a) shows the vibration-proof structure of Figure 23 in its natural state, similar to Figure 23, and Figure 26(b) is a cross-sectional view showing, in outline, the state in which the vibration-proof structure of Figure 26(a) is pressed into the inner surface of a cylindrical portion of an external member. Figure 27(a) is a front view that shows, in outline, the appearance of the vibration-proof structure and external member shown in Figure 26(b) when viewed from one side in the axial direction, and Figure 27(b) is a side view that shows, in outline, the appearance of the vibration-proof structure and external member shown in Figure 27(a) when viewed from the radially outer side. 10 is a front view showing a fifth modified example of the vibration-proof structure of FIG. 1 as viewed from one side in the axial direction. FIG. 10 is a front view showing a sixth modified example of the vibration-proof structure of FIG. 1 as viewed from one side in the axial direction. FIG. 10 is a cross-sectional view showing a seventh modified example of the vibration-proof structure of FIG. Figure 31(a) is a side view that shows, in outline, the appearance of one of the partial outer tube members in Figure 30 when viewed from the radial outside, and Figure 31(b) is a front view that shows, in outline, the appearance of the partial outer tube member in Figure 31(a) when viewed from one axial side.

The vibration-proof structure, strut mount, and method for manufacturing a vibration-proof structure according to the present invention are suitable for application to a vehicle suspension device, for example, a MacPherson strut suspension device. The vibration-proof structure and method for manufacturing a vibration-proof structure according to the present invention are suitable for use as a bush used in a link mechanism (such as a suspension link arm) of a vehicle suspension device (for example, a MacPherson strut suspension device), or are suitable for use in a strut mount of a vehicle suspension device (for example, a MacPherson strut suspension device).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the vibration-proof structure, strut mount, and method for manufacturing the vibration-proof structure according to the present invention will be described with reference to the drawings.

1 to 7 and 17 to 31 are diagrams for explaining a vibration-proof structure 1 according to a first embodiment of the present invention and its modified example, and a manufacturing method thereof. In the first embodiment, the vibration-proof structure 1 is configured as a bush used in a link mechanism (such as a suspension link arm) of a suspension device of a vehicle.
8 to 16 are diagrams illustrating a vibration-proof structure 1 and a manufacturing method thereof according to a second embodiment and its modified example of the present invention. In the second embodiment, the vibration-proof structure 1 is provided in a strut mount 7 of a suspension device of a vehicle.
For convenience of explanation, these embodiments will be described in parallel below.

1 is a cross-sectional view that shows a schematic diagram of a vibration-proof structure 1 according to a first embodiment of the present invention. As described above, in the first embodiment, the vibration-proof structure 1 is configured as a bush used in a link mechanism (such as a suspension link arm) of a suspension device of a vehicle. In this embodiment, the axial direction of the vibration-proof structure 1 is oriented substantially horizontally.
1, in the first embodiment, the vibration-proof structure 1 includes an inner tube 2, an outer tube 3, and a main rubber body 4. The configuration of these components will be described later.

8 is a cross-sectional view showing a strut mount 7 equipped with a vibration-proof structure 1 according to a second embodiment of the present invention. As described above, in the second embodiment, the vibration-proof structure 1 is provided in a strut mount 7 of a suspension device of a vehicle. In this embodiment, the axial direction of the vibration-proof structure 1 is oriented substantially vertically.
Although not shown, the suspension device includes a strut mount 7, a shock absorber, and a spring 8.
The shock absorber includes a damper rod 6 and a cylinder. The cylinder is located below the damper rod 6 and is disposed coaxially with the damper rod 6.
The strut mount 7 is attached to the upper end of the damper rod 6 .
The spring 8 is configured to support the damper rod 6 and the strut mount 7 together in an upwardly biased state so as to be movable downward. The lower end of the spring 8 is supported by a receiving portion fixed to the cylinder of the shock absorber.
In the example of FIG. 8 , the strut mount 7 includes the vibration-proof structure 1 , a bracket 71 , a bearing 72 , and a spring seat 73 .
As shown in FIG. 8 , in the second embodiment, the vibration-proof structure 1 includes an inner tube 2 , an outer tube 3 , and a main rubber body 4 .
The bracket 71 is configured to be attached to a vehicle body. In the example shown in Fig. 8, the bracket 71 has a bracket tubular portion 711, a bracket flange portion 712, a bracket upper annular portion 715, and a bracket lower annular portion 716.
The bracket tubular portion 711 is configured in a tubular shape extending in the axial direction of the vibration-proof structure 1 .
The bracket upper annular portion 715 extends radially inward from an upper portion of the bracket tubular portion 711. The bracket upper annular portion 715 has an annular shape.
The bracket lower annular portion 716 extends radially inward from the bracket tubular portion 711 below the bracket upper annular portion 715. The bracket lower annular portion 716 has an annular shape.
The inner peripheral end of the bracket upper annular portion 715 and the inner peripheral end of the bracket lower annular portion 716 define a central through hole 713 that passes through the bracket 71 in the axial direction. The central through hole 717 of the bracket 71 is configured so that the upper end of the damper rod 6 is inserted therein.
The bracket flange portion 712 protrudes outward from an upper portion of the bracket tubular portion 711. The bracket flange portion 712 is configured to be attached to the vehicle body by being fastened to the vehicle body via one or more fasteners F1. The fasteners F1 are, for example, bolts.
However, the bracket 71 may be configured to be attached to the vehicle body by a means other than fastening with the fastener F1.
The vibration-proof structure 1 is disposed on the inner peripheral side of the bracket tubular portion 711, between the bracket upper annular portion 715 and the bracket lower annular portion 716 in the axial direction. The outer cylinder 3 of the vibration-proof structure 1 is in contact with the inner peripheral surface of the bracket tubular portion 711, and is fitted into the inner peripheral surface of the bracket tubular portion 711 by press-fitting or the like. The outer cylinder 3 of the vibration-proof structure 1 is coaxial with the bracket tubular portion 711.
The damper rod 6 has a mounting portion 61 at its upper end. The mounting portion 61 has a smaller diameter than the portion of the damper rod 6 below the mounting portion 61. The upper portion of the mounting portion 61 has a male thread formed on its outer circumferential surface. The damper rod 6 has a step surface 62 that extends from the lower end of the mounting portion 61 to the outer circumferential side and faces upward. The step surface 62 is located between the bracket upper annular portion 715 and the bracket lower annular portion 716 in the axial direction. The inner tube 2 of the vibration-proof structure 1 is configured to be attached to the damper rod 6 by inserting the mounting portion 61 of the damper rod 6 into a central through hole defined by the inner circumferential surface of the inner tube 2, and tightening the upper end surface of the inner tube 2 from above with a fastener F2 such as a nut, with the lower end surface of the inner tube 2 in contact with the step surface 62 of the damper rod 6. In this manner, with the mounting portion 61 of the damper rod 6 inserted through the central through-hole of the inner cylinder 2 of the vibration-proof structure 1, the inner cylinder 2 and the damper rod 6 are coaxial.
The bearing 72 is located on the outer circumferential side of the bracket tubular portion 711 and is in contact with the bracket flange portion 712 from below.
The spring seat 73 is in contact with the bearing 72 from below. The upper end of the spring 8 is in contact with the spring seat 73 from below.
The bearing 72 supports the bracket 71 and the vibration-proof structure 1 fitted therein as a whole so as to be rotatable about the central axis O3 of the vibration-proof structure 1 relative to the spring seat 73 (and thus the spring 8). This makes it possible to absorb the rotation of the spring 8 when, for example, the vehicle turns.
However, the strut mount 7 may have any configuration other than that of the vibration-proof structure 1 described in this specification, different from the example shown in FIG.

The vibration-proof structure 1 in the first embodiment (FIG. 1), the second embodiment (FIG. 8), and their modified examples will be described in more detail below. FIG. 7 is a drawing for explaining a first modified example of the first embodiment. FIG. 17 is a drawing for explaining a second modified example of the first embodiment. FIG. 20 is a drawing for explaining a third modified example of the first embodiment. FIGS. 21 to 27 are drawings for explaining a fourth modified example of the first embodiment. FIG. 28 is a drawing for explaining a fifth modified example of the first embodiment. FIG. 29 is a drawing for explaining a sixth modified example of the first embodiment. FIGS. 30 to 31 are drawings for explaining a seventh modified example of the first embodiment. FIGS. 15 to 16 are drawings for explaining a modified example of the second embodiment. The matters described below are applicable to each of the examples described in this specification unless otherwise specified.

In this specification, when describing the vibration-proof structure 1, for convenience, unless otherwise specified, the description will be given of the structure when no input or other external force is applied to the vibration-proof structure 1 and the vibration-proof structure 1 is in a stationary, normal state (also referred to as the "natural state" in this specification) as shown in Figures 1 and 8, etc.
1, 7, 8, 15, 17, 20, 21 to 23, and 28 to 30, the vibration-proof structure 1 is in a natural state.

As described above, the vibration-proof structure 1 comprises an inner tube 2, an outer tube 3, and a main body rubber 4 (Figs. 1, 7, 8, 15, 17, 20, 23, 28 to 30).

The outer cylinder 3 is located on the outer peripheral side of the inner cylinder 2. The inner cylinder 2 is arranged coaxially with the outer cylinder 3; in other words, the central axis O2 of the inner cylinder 2 coincides with the central axis O3 of the outer cylinder 3.

In this specification, the central axis O3 of the outer cylinder 3 is regarded as the central axis O3 of the vibration-proof structure 1. In addition, in this specification, unless otherwise specified, the direction parallel to the central axis O3 of the vibration-proof structure 1 is referred to as the "axial direction", the side farther from the center of the vibration-proof structure 1 in the axial direction is referred to as the "axial outer side", the side closer to the center of the vibration-proof structure 1 in the axial direction is referred to as the "axial inner side", the direction perpendicular to the central axis O3 of the vibration-proof structure 1 is referred to as the "axial perpendicular direction", the side closer to the central axis O3 of the vibration-proof structure 1 is referred to as the "inner peripheral side", the side farther from the central axis O3 of the vibration-proof structure 1 is referred to as the "outer peripheral side", the circumferential direction centered on the central axis O3 of the vibration-proof structure 1 is referred to as the "circumferential direction", and the radial direction centered on the central axis O3 of the vibration-proof structure 1 is referred to as the "radial direction".

The main body rubber 4 is made of rubber. The main body rubber 4 is located between the inner tube 2 and the outer tube 3 in the radial direction. The main body rubber 4 connects the inner tube 2 and the outer tube 3 to each other. The main body rubber 4 extends around the entire circumference between the inner tube 2 and the outer tube 3, and thus has a cylindrical shape.

It is preferable that the outer peripheral surface of the main rubber 4 is bonded to the inner peripheral surface of the outer tube 3 over the entire circumference. The main rubber 4 may be bonded to the outer tube 3 over the entire portion of the main rubber 4 that is in contact with the outer tube 3. The bond between the main rubber 4 and the outer tube 3 may be achieved by any method, such as vulcanization adhesion and/or adhesion via an adhesive.

The inner circumferential surface of the main body rubber 4 has a pair of joint portions 41 and a non-joint portion 42 (FIGS. 1, 7, 8, 15, 17, 20, 23, and 30).
For ease of understanding, in each drawing, the area where the joint 41 exists is hatched with dots.

A pair of joints 41 on the inner surface of the main rubber 4 are located on both axial sides of the axial center of the vibration-proof structure 1 (the same axial position as the axial center of the outer tube 3), and are each joined around the entire circumference to the outer circumferential surface and/or axial end face of the inner tube 2 (Figures 1, 7, 8, 15, 17, 20, 23, 30).
For example, in the first embodiment shown in Fig. 1 and the modified examples shown in Figs. 7, 20, 23, and 30, a pair of joints 41 are joined to the outer peripheral surface of the inner tube 2 (more specifically, both end portions of the outer peripheral surface in the axial direction). In the second embodiment shown in Fig. 8, the inner peripheral surface of the main rubber 4 has two pairs of joints 41, one pair of joints 41 of which is joined to the outer peripheral surface of the inner tube 2 (more specifically, both end portions of the outer peripheral surface in the axial direction), and the other pair of joints 41 is joined to both end surfaces of the inner tube 2 in the axial direction. In the modified example shown in Fig. 15, the pair of joints 41 are joined to both end surfaces of the inner tube 2 in the axial direction.
In each of the examples described in this specification, the inner surface of the main rubber 4 may have only one pair of joints 41 located on both sides in the axial direction, as in the examples of Figures 1, 7, 15, 17, 20, 23, and 30, or the inner surface of the main rubber 4 may have multiple pairs of joints 41 located on both sides in the axial direction, as in the example of Figure 8.
In each example described in this specification, for example in the example of Figure 8, each of the pair of joints 41 may be joined to both the outer peripheral surface and the axial end face of the inner tube 2 by integrally constructing a joint 41 joined to the outer peripheral surface of the inner tube 2 and a joint 41 joined to the axial end face of the inner tube 2 on both axial sides of the axial center of the vibration-proof structure 1.

The non-jointed portion 42 on the inner peripheral surface of the main rubber 4 extends between a pair of jointed portions 41 (if there are multiple pairs of jointed portions 41, any pair of the jointed portions 41) (FIGS. 1, 7, 8, 15, 17, 20, 23, 30). The non-jointed portion 42 is not joined to but is in contact with the inner tube 2 (specifically, the outer peripheral surface of the inner tube 2). The non-jointed portion 42 is located in the center of the vibration-proof structure 1 in the axial direction, and is located on the center of the vibration-proof structure 1 in the axial direction.
In the second embodiment ( FIG. 8 ), the non-jointed portion 42 extends between one pair of joint portions 41 that is joined to the outer circumferential surface of the inner cylinder 2, out of the two pairs of joint portions 41. The non-jointed portion 42 extends from one joint portion 41 to the other joint portion 41 of the pair of joint portions 41, and connects the pair of joint portions 41 to each other.
In this specification, "in contact" with respect to the relationship between the main rubber 4 and the inner tube 2 does not mean limited to the case where the main rubber 4 and the inner tube 2 are in direct contact with nothing interposed between them, but also includes the case where a lubricant 5 is interposed between the main rubber 4 and the inner tube 2 as described below (Figures 1 and 8), but excludes the case where a member or space other than the lubricant 5 is interposed between the main rubber 4 and the inner tube 2.

In addition, in the drawings such as Figures 1, 7, 8, and 15, the gap G between the main rubber 4 and the inner tube 2 at the non-jointed portion 42 (also referred to as the "non-jointed portion gap G" in this specification) is shown partially exaggerated in order to make it easier to understand the area where the non-jointed portion 42 exists. However, in reality, since the main rubber 4 and the inner tube 2 are in contact at the non-jointed portion 42, this gap G is almost or completely collapsed.

1 to 2, 7, 8 to 9, and 15 to 16, in this specification, the portion of the surface of the inner tube 2 that is joined to the joint portion 41 of the main body rubber 4 is referred to as the "joint portion 21," and the portion that is not joined but is in contact with the non-joint portion 42 of the main body rubber 4 is referred to as the "non-joint portion 22." The joint portion 21 is located on the outer circumferential surface and/or the axial end surface of the inner tube 2.
For ease of understanding, in each drawing, the area where the joint 21 exists is hatched with dots.
1 and 2 and the modified examples shown in Figures 7, 17, 20, 23, and 30, the outer circumferential surface of the inner cylinder 2 has a pair of joints 21 located on both axial sides of the axial center of the vibration-proof structure 1 and a non-jointed portion 22 therebetween. The pair of joints 21 are located on both axial end portions of the outer circumferential surface of the inner cylinder 2.
8 and 9, the outer peripheral surface of the inner cylinder 2 has a pair of joints 21 located on both axial sides of the axial center of the vibration-proof structure 1 and a non-jointed portion 22 therebetween, and both axial end faces of the inner cylinder 2 have a further pair of joints 21 located on both axial sides of the axial center of the vibration-proof structure 1. Of the two pairs of joints 21 of the inner cylinder 2, one pair of joints 21 is located at both axial ends of the outer peripheral surface of the inner cylinder 2, and the other pair of joints 41 is located at both axial end faces of the inner cylinder 2.
In the modified example shown in Figures 15 and 16, both axial end faces of the inner tube 2 have a pair of joint portions 21 located on both axial sides of the axial center of the vibration-proof structure 1, and the outer circumferential surface of the inner tube 2 has non-joint portions 22 over its entirety.
The non-jointed portion 22 in the inner tube 2 extends between a pair of jointed portions 21 (if there are multiple pairs of jointed portions 21, any one of those pairs of jointed portions 21). In the second embodiment (FIGS. 8 to 9), the non-jointed portion 22 extends between one of the two pairs of jointed portions 21 that is located on the outer circumferential surface of the inner tube 2. The non-jointed portion 22 extends from one jointed portion 21 to the other jointed portion 21, connecting the pair of jointed portions 21. The non-jointed portion 22 is located in the center of the vibration-proof structure 1 in the axial direction, and is located on the axial center of the vibration-proof structure 1.

The joining between the main rubber 4 and the inner tube 2 at the joints 41, 21 may be achieved by any method, such as vulcanization adhesion and/or adhesion via an adhesive.
An example of a method for forming the bonded portions 41, 21 and the non-bonded portions 42, 22 will be described in more detail later.

In each example described in this specification, as mentioned above, the main rubber 4 is joined to the inner tube 2 around its entire circumference at a pair of joints 41 on both sides in the axial direction, and the non-jointed portion 42 between the pair of joints 41 is not joined to the inner tube 2 but is in contact with it (Figures 1, 7, 8, 15, 17, 20, 23, 30).
Therefore, when the inner tube 2 is displaced relative to the outer tube 3 in a torsional direction (the direction in which the inner tube 2 rotates circumferentially relative to the outer tube 3) or a twisting direction (the direction in which the central axis O2 of the inner tube 2 is inclined relative to the central axis O3 of the outer tube 3 as shown in Figures 6 and 13), the main rubber 4 is fixed to the inner tube 2 at a pair of joints 21 on both sides in the axial direction, but can slide on the inner tube 2 at the non-jointed portion 22 therebetween, as illustrated in Figures 6 and 13. Therefore, during displacement in the torsional or twisting direction, the portions of the main rubber 4 in the vicinity of the pair of joints 41 contribute to the spring rigidity, but the portions of the main rubber 4 in the vicinity of the non-jointed portion 42 contribute little or nothing to the spring rigidity. Therefore, compared to a case where the main body rubber 4 is bonded to the inner tube 2 over the entire surface thereof, the area of the portion where the main body rubber 4 is bonded to the inner tube 2 is smaller, and the rigidity in the torsional and prying directions can be reduced accordingly, and ultimately the inner tube 2 can more easily swing in the torsional and prying directions relative to the outer tube 3. This improves the performance as a vibration-proof structure for a vehicle suspension device.
In addition, in each example described in this specification, the simple configuration of the joint between the main rubber 4 and the inner tube 2 as described above has the advantage that the above-mentioned effects can be obtained without the need for additional parts (i.e., while preventing an increase in the number of parts).
Furthermore, each of the examples described in this specification has the advantage that a smooth sliding structure can be realized not only in the torsional direction, but also in both the torsional and prying directions.
Furthermore, in each of the examples described in this specification, the presence of the non-jointed portion 42 of the main rubber 4 does not affect the displacement perpendicular to the axis, so that the main rubber 4 can exhibit high spring rigidity equal to or greater than that of conventional rubber when the inner tube 2 is displaced relative to the outer tube 3 in the direction perpendicular to the axis, and thus can exhibit good performance as a vibration-proof structure for a vehicle suspension device.
In each example described in this specification, as described above, the pair of joints 41 on both sides of the non-jointed portion 42 in the main rubber 4 are joined to the inner tube 2 over the entire circumference, so that the gap G between the non-jointed portion 22 of the inner tube 2 and the non-jointed portion 42 of the main rubber 4 becomes an enclosed space sealed by the pair of joints 41 on both sides. Therefore, it is possible to prevent dust and the like from entering this gap G from the outside without requiring any additional members (sealing members, etc.) (i.e., while preventing an increase in the number of parts), and thus it is possible to prevent a decrease in the sliding property between the main rubber 4 and the inner tube 2 therein. Furthermore, even if the gap G is filled with the lubricant 5 as described below, it is possible to prevent the lubricant 5 from leaking out from between the main rubber 4 and the inner tube 2 without requiring any additional members (sealing members, etc.) (i.e., while preventing an increase in the number of parts).

As described above, the bushing of the vibration-proof structure 1 (Figure 1) of the first embodiment has a portion (non-jointed portion 42) where the main rubber 4 can slide against the inner tube 2, and therefore can be said to be a so-called "sliding type bushing."
Furthermore, as described above, the strut mount equipped with the vibration-proof structure 1 of the second embodiment (Figure 8) has a portion (non-jointed portion 42) where the main rubber 4 can slide against the inner tube 2, and so can be said to be a so-called "sliding-type strut mount".

In each example described in this specification, as shown in Figures 1, 8, 15, 17, and 20, it is preferable that a lubricant 5 is interposed between the non-jointed portion 22 of the inner tube 2 and the non-jointed portion 42 of the main rubber 4. In this case, the lubricant 5 is filled in the gap G between the non-jointed portion 22 of the inner tube 2 and the non-jointed portion 42 of the main rubber 4.
As described above, the gap G is exaggerated in Figures 1, 8, 15, 17, and 20, but in reality, the gap G is almost or completely collapsed. Therefore, the layer thickness of the lubricant 5 is actually very thin. In this case, the non-jointed portion 22 of the inner tube 2 and the non-jointed portion 42 of the main rubber 4 come into contact with each other via the lubricant 5.
The lubricant 5 is made of, for example, lubricating oil.
By interposing the lubricant 5 between the non-jointed portion 22 of the inner tube 2 and the non-jointed portion 42 of the main body rubber 4, the frictional resistance between the non-jointed portion 22 of the inner tube 2 and the non-jointed portion 42 of the main body rubber 4 can be reduced, and thus the non-jointed portion 42 of the main body rubber 4 can slide more easily against the non-jointed portion 22 of the inner tube 2. This makes it easier for the inner tube 2 to swing in the twisting and twisting directions.
However, the lubricant 5 does not have to be interposed between the non-jointed portion 22 of the inner tube 2 and the non-jointed portion 42 of the main rubber 4 .

In each example described in this specification, as in the example shown in FIG. 1, the inner cylinder 2 may be integrally formed throughout, and may be made of the same material throughout.
Alternatively, in each example described in this specification, the inner cylinder 2 may be composed of a plurality of parts made of different materials, as in the examples shown in Figures 7, 8, and 15. For example, as in the examples shown in Figures 7, 8, and 15, the inner cylinder 2 may have an inner cylinder inner peripheral portion 25 and an inner cylinder outer peripheral portion 26 located on the outer periphery side of the inner cylinder inner peripheral portion 25. The inner cylinder inner peripheral portion 25 and the inner cylinder outer peripheral portion 26 are made of different materials. The inner cylinder inner peripheral portion 25 defines a central through hole passing along the central axis O2 by its inner peripheral surface.
Examples of materials that form the inner cylinder 2 include metal and/or resin.

In each example described in this specification, it is preferable that at least a part of the non-jointed portion 22 of the inner tube 2 (preferably the entire non-jointed portion 22) is made of a relatively slippery (i.e., low frictional resistance) material (hereinafter referred to as a "low friction resistance material"). This reduces the frictional resistance between the non-jointed portion 22 of the inner tube 2 and the non-jointed portion 42 of the main rubber 4, and thus the non-jointed portion 42 of the main rubber 4 can slide easily against the non-jointed portion 22 of the inner tube 2. This configuration is particularly preferable when no lubricant 5 is interposed between the non-jointed portion 22 of the inner tube 2 and the non-jointed portion 42 of the main rubber 4. Even when no lubricant 5 is interposed between the non-jointed portion 22 of the inner tube 2 and the non-jointed portion 42 of the main rubber 4, it is possible to reduce the frictional resistance between the non-jointed portion 22 of the inner tube 2 and the non-jointed portion 42 of the main rubber 4 by using a low friction resistance material for the inner tube 2 as described above.
The low friction resistance material is preferably, for example, a resin, such as polyacetal, which may be either fiber-reinforced or non-fiber-reinforced.
For example, as described above, when the inner cylinder 2 has the inner cylinder inner peripheral portion 25 and the inner cylinder outer peripheral portion 26 located on the outer peripheral side of the inner cylinder inner peripheral portion 25 (FIGS. 7, 8, 15), the outer peripheral surface of the inner cylinder outer peripheral portion 26 may constitute at least a part of the non-jointed portion 22 (in the examples of FIGS. 7, 8, 15, the entire non-jointed portion 22), and the inner cylinder outer peripheral portion 26 may be made of a low friction resistance material. In this case, the inner cylinder inner peripheral portion 25 may be made of a material (e.g., a metal) having a higher friction resistance and/or strength than the low friction resistance material constituting the inner cylinder outer peripheral portion 26.
In the examples of Figures 7, 8, and 15, each joint 21 is formed by the outer peripheral surface or axial end face of the inner tube outer peripheral portion 26, but each joint 21 may be formed by the outer peripheral surface and/or axial end face of the inner tube inner peripheral portion 25.
Furthermore, the portion of the inner tube 2 that constitutes the joint portion 21 may be made of the same material as the portion of the inner tube 2 that constitutes the non-joint portion 22, or it may be made of a different material.
Moreover, the entire inner cylinder 2 may be made of a low friction resistance material.

In each example described in this specification, it is preferable that the outer peripheral surface of the inner tube 2 has a bulge-shaped portion 23 that has a bulge shape that protrudes toward the outer peripheral side, as in the examples of Figures 1 to 2, 7, 8 to 9, 15 to 16, 17, 20, 23, and 30. In this case, the portion of the inner peripheral surface of the main rubber 4 that contacts the bulge-shaped portion 23 of the inner tube 2 forms a concave shape that is recessed toward the outer peripheral side to fit the bulge-shaped portion 23. It is preferable that the bulge-shaped portion 23 extends around the entire circumference to form an annular shape.
When the outer surface of the inner tube 2 has a bulge-shaped portion 23, the thickness of the main rubber 4 in the axial direction (up and down direction in Figure 1, left and right direction in Figure 8) is relatively thin in the portion of the main rubber 4 that faces the bulge-shaped portion 23 in the axial direction, and therefore the main rubber 4 can exhibit higher spring rigidity against relative displacement of the inner tube 2 in the axial direction.
In each example described in this specification, as in each of the examples in Figures 1 to 2, 8 to 9, 17, 20, 23, and 30, the outer circumferential surface of the inner cylinder 2 may have a bulge-shaped portion 23 and a pair of non-bulge-shaped portions 24 that are located on both sides of the bulge-shaped portion 23 in the axial direction and do not form a bulge shape. The non-bulge-shaped portions 24 may be configured in a linear shape (e.g., a cylindrical shape) along the axial direction throughout the entire non-bulge-shaped portion 24, as in each of the examples in Figures 1 to 2, 7, 8 to 9, 17, and 20, for example.
Alternatively, in each example described in this specification, the outer circumferential surface of the inner cylinder 2 may have only the bulge-shaped portion 23, as in the example of Figs.

In each example described in this specification, when the outer peripheral surface of the inner tube 2 has a bulge-shaped portion 23 as described above, as in the examples of Figures 1 to 2, 7, 8 to 9, 15 to 16, 17, 20, 23, and 30, it is preferable that a pair of joint portions 41 of the main rubber 4 are joined around the entire circumference to at least a portion of the outer peripheral surface of the inner tube 2 excluding the bulge-shaped portion 23 (i.e., the non-bulge-shaped portion 24) and/or at least a portion of the axial end face of the inner tube 2, and that the non-joint portion 42 of the main rubber 4 is not joined to but is in contact with the bulge-shaped portion 23 of the inner tube 2 (i.e., the bulge-shaped portion 23 forms the non-joint portion 22).
In this case, when the inner tube 2 is displaced in the prying direction, the non-jointed portion 42 of the main rubber 4 slides more easily against the non-jointed portion 22 consisting of the bulge-shaped portion 23 of the inner tube 2 (FIGS. 6 and 13). Therefore, the spring rigidity against displacement in the prying direction can be further reduced.
1 to 2, 7, 17, 20, 23, and 30, the pair of joint portions 41 of the main rubber 4 are joined over the entire circumference to at least a part of a pair of non-bulge shaped portions 24 located on both sides of the bulge shaped portion 23 in the axial direction on the outer circumferential surface of the inner tube 2, and the non-joined portion 42 of the main rubber 4 is not joined to but is in contact with the entire bulge shaped portion 23 of the inner tube 2. In the examples of Figs. 8 to 9, one pair of joint portions 41 of the two pairs of joint portions 41 of the main rubber 4 is joined over the entire circumference to a pair of non-bulge shaped portions 24 located on both sides of the bulge shaped portion 23 in the axial direction on the outer circumferential surface of the inner tube 2, and one pair of joint portions 41 of the two pairs of joint portions 41 of the main rubber 4 is joined over the entire circumference to both axial end faces of the inner tube 2, and the non-joined portion 42 of the main rubber 4 is not joined to but is in contact with the entire bulge shaped portion 23 of the inner tube 2. In the example of Figures 15 and 16, a pair of joint portions 41 of the main rubber 4 are joined around the entire circumference to at least a portion of both axial end faces of the inner tube 2, and the non-joint portion 42 of the main rubber 4 is not joined to the entire bulge-shaped portion 23 of the inner tube 2 but is in contact with it.

In each example described in this specification, when the outer peripheral surface of the inner tube 2 has a bulge-shaped portion 23 as described above, the bulge shape of the bulge-shaped portion 23 may be any shape as long as it protrudes toward the outer periphery.
It is preferable that the bulge shape of the bulge-shaped portion 23 includes a curved portion as in the examples of Figures 1 to 2, 7, 8 to 9, 15 to 16, 17, 20, 23, and 30. In this case, when the inner tube 2 is displaced in the prying direction, the non-jointed portion 42 of the main body rubber 4 slides more easily against the non-jointed portion 22 of the bulge-shaped portion 23 of the inner tube 2. The bulge shape of the bulge-shaped portion 23 may be one that is made up of only a curved surface.
It is preferable that the bulge shape of the bulge-shaped portion 23 is a shape without any angular edges, as in the examples of Figures 1 to 2, 7, 8 to 9, 15 to 16, 17, 20, 23, and 30. In this case, when the inner tube 2 is displaced in the prying direction, the non-jointed portion 42 of the main body rubber 4 is more likely to slide against the non-jointed portion 22 consisting of the bulge-shaped portion 23 of the inner tube 2.
It is preferable that the bulge shape of the bulge-shaped portion 23 be a shape that gradually approaches the outer periphery as it approaches the axial center of the vibration-proof structure 1, as in the examples of Figures 1 to 2, 7, 8 to 9, 15 to 16, 17, 20, 23, and 30. In this case, when the inner tube 2 is displaced in the prying direction, the non-jointed portion 42 of the main body rubber 4 is more likely to slide against the non-jointed portion 22 consisting of the bulge-shaped portion 23 of the inner tube 2.
The bulge shape of the bulge-shaped portion 23 may be, for example, a spherical shape.

When the vibration-proof structure 1 is provided on the strut mount 7, it is preferable that the main rubber 4 has stopper portions 43 that protrude outward in the axial direction at both axial end faces, as in the examples of Figures 8 to 9 and Figures 15 to 16. It is preferable that the stopper portions 43 are located on the axial end faces of the inner tube 2. It is preferable that the stopper portions 43 are disposed so as to face the bracket upper annular portion 715 or the bracket lower annular portion 716 of the bracket 71 in the axial direction. As in the example shown in Figure 8, it is preferable that the stopper portions 43 contact the bracket upper annular portion 715 or the bracket lower annular portion 716 during normal times when there is no input to the inner tube 2, but they do not have to be in contact.
14 , when the damper rod 6 and inner cylinder 2 are displaced together in the axial direction relative to the outer cylinder 3, the stopper portion 43 is compressed between the inner cylinder 2 and the bracket upper annular portion 715 or the bracket lower annular portion 716, thereby effectively stopping the axial displacement of the damper rod 6 and inner cylinder 2 while mitigating the impact between the inner cylinder 2 and the bracket 71. This configuration is advantageous as the strut mount 7 may be subjected to a large axial input.
As shown in the examples of Figures 8 to 9 and Figures 15 to 16, it is preferable that at least a part of the axially inner surface of each stopper portion 43 forms a joint portion 41 that is joined to the axial end surface of the inner cylinder 2. This makes it possible to suppress positional deviation of the stopper portion 43.
The stopper portion 43 may extend around the entire circumference so as to form an annular shape, or a plurality of stopper portions 43 may be arranged spaced apart from each other along the circumferential direction.
However, the stopper portion 43 may be omitted.

Figure 17 is a cross-sectional view that shows a schematic of a second modified example of the vibration-proof structure 1 in Figure 1. Figure 20 is a cross-sectional view that shows a schematic of a third modified example of the vibration-proof structure 1 in Figure 1.

In each example described in this specification, it is preferable that the outer tube 3 has a straight portion 3S extending parallel to the axial direction, as in each example shown in Figures 1, 7, 8, 15, 17, and 20. The straight portion 3S only needs to have at least its inner peripheral surface extending parallel to the axial direction. The outer peripheral surface of the straight portion 3S may extend parallel to the axial direction as in each example shown in Figures 1, 7, 8, 15, 17, and 20, or may extend non-parallel to the axial direction. The straight portion 3S extends continuously from at least the axial center of the vibration-proof structure 1 (and thus the axial center of the outer tube 3) to the axial position of at least a part (preferably the entirety) of each of the pair of joint portions 41 of the main rubber body 4. The straight portion 3S is located on the outer circumferential side of the entire non-jointed portion 42 of the main body rubber 4 over its entire circumference, and is also located on the outer circumferential side of at least a portion (preferably all) of each of a pair of joined portions 41 of the main body rubber 4.
This ensures a large radial thickness in the vicinity of the pair of joints 41 of the main rubber 4 compared to, for example, a case in which the outer tube 3 gradually becomes smaller in diameter toward the axial outside in an axial region extending from the axial center of the vibration-proof structure 1 to at least a part of each of the pair of joints 41 of the main rubber 4. This improves the durability of the vicinity of the pair of joints 41 of the main rubber 4. The vicinity of the pair of joints 41 of the main rubber 4 is connected to the inner tube 2 and the outer tube 3 on the radial inside and outside, and therefore is a portion that expands and contracts more than the vicinity of the non-jointed portions 42 of the main rubber 4 when the inner tube 2 is relatively displaced in the twisting direction, prying direction, etc., and therefore it is desirable for the vicinity of the pair of joints 41 to have high durability.

As shown in the examples in Figures 1, 7, 8, and 15, the outer cylinder 3 may be composed of only the straight portion 3S.

17 and 20, the outer cylinder 3 may further have, in addition to the straight portion 3S, a pair of vertical portions 3V extending in parallel to the axial direction from both axial outer ends of the straight portion 3S toward the radially inward direction. It is preferable that the radially inner ends of the vertical portions 3V are spaced outward from the outer circumferential surface of the inner cylinder 2.
When the outer cylinder 3 has a pair of vertical portions 3V, the rigidity in the axial direction can be increased, and the effect of suppressing displacement in the axial direction can be improved. This improves the performance as a vibration-proof structure for a vehicle suspension device.
Furthermore, when the outer tube 3 has a pair of vertical portions 3V, the vertical portions 3V can effectively suppress the axial expansion of the portion of the main rubber 4 that is compressed (the lower portion in FIG. 18) when the inner tube 2 undergoes relative displacement in the axial direction (FIG. 18), compared to when the outer tube 3 is made of only the straight portions 3S, or when the outer tube 3 has, in addition to the straight portions 3S, portions that extend in a direction inclined in the axial direction radially inward from both axial outer ends of the straight portions 3S, and thus can increase the spring rigidity in the axial direction. This can improve the performance as a vibration-proof structure for a vehicle suspension device.
In this case, as in each of the modified examples shown in Figures 17 and 20, it is preferable that the main rubber 4 is joined to, or is in contact with, at least a portion of the axial inner surface of a pair of vertical portions 3V of the outer tube 3 without being joined.

As shown in the example of FIG. 17, the outer cylinder 3 may be composed only of a straight portion 3S and a pair of vertical portions 3V on both sides of the straight portion 3S in the axial direction.

When the outer tube 3 has a straight portion 3S and a pair of vertical portions 3V, the outer tube 3 may further have a pair of protruding portions 3E extending parallel to the axial direction from the radial inner ends of the pair of vertical portions 3V toward the axial outward direction, as in the modified example shown in Figure 20.
In this case, as in the example shown in Figure 20, it is preferable that the main rubber 4 is joined to at least a portion of the inner surface of a pair of protrusions 3E of the outer tube 3, or is not joined but is in contact with the inner surface of the pair of protrusions 3E.

In each example described in this specification, it is preferable that the outer peripheral surface of the outer cylinder 3 does not have a portion that extends outward (i.e., expands in diameter) as it moves outward in the axial direction, as in the examples shown in Figures 1, 7, 8, 15, 17, and 20. In this case, it becomes easier to press the vibration-proof structure 1 into the inner peripheral surface of an external cylindrical member (for example, the bracket cylindrical portion 711 of the bracket 71 in the example of Figure 8).
In each example described in this specification, it is preferable that the outer tube 3 does not have a portion extending in a direction inclined with respect to both the axial direction and the direction perpendicular to the axis, as in the examples shown in Figures 1, 7, 8, 15, 17, and 20.

The vibration-proof structure 1 of each example described in this specification may be used for any purpose other than the above-mentioned purposes. Furthermore, the axial direction of the vibration-proof structure 1 may be oriented in any direction.

Hereinafter, an embodiment of a method for manufacturing a vibration-proof structure of the present invention will be described. This manufacturing method can be suitably used for manufacturing the vibration-proof structure 1 of each example described in this specification.
In this manufacturing method, through a vulcanization process, an anti-vibration structure 1 is produced which comprises an inner tube 2, an outer tube 3, and a main body rubber 4 which connects the inner tube 2 and the outer tube 3 together, and the inner surface of the main body rubber 4 has a pair of joints 41 and a non-jointed portion 42 therebetween.
For example, in the injection process, unvulcanized rubber for forming the main rubber 4 is injected into a mold in which the inner tube 2 and the outer tube 3 are set, and then, in the vulcanization process, the vibration-proof structure 1 is vulcanized and molded using the mold.

The bonded portion 41 and the non-bonded portion 42 are preferably formed in a vulcanization process.
One method of forming the joint portion 41 and the non-joint portion 42 in the vulcanization process is as follows. First, in an adhesive application process before the vulcanization process, the portion of the surface of the inner tube 2 that will become the non-joint portion 22 is masked, and then the adhesive is applied to the portion of the surface of the inner tube 2 that will become the joint portion 21. This prevents the adhesive from being applied to the portion of the surface of the inner tube 2 that will become the non-joint portion 22. The masking is then removed. Then, in an injection process, unvulcanized rubber for forming the main body rubber 4 is injected into a mold in which the inner tube 2 and the outer tube 3 are set, and then, in a vulcanization process, the vibration-proof structure 1 is vulcanized and molded by the mold. In this case, during the vulcanization process, the main body rubber 4 is bonded to the portion of the surface of the inner tube 2 where the adhesive is applied, where the joint portion 41 is formed, and is not bonded to the portion of the surface of the inner tube 2 that was masked (i.e., where the adhesive was not applied), where the non-joint portion 42 is formed.
Another method for forming the joint portion 41 and the non-joint portion 42 in the vulcanization process is as follows. First, in an adhesive sheet attachment process before the vulcanization process, an adhesive sheet is attached to the portion of the surface of the inner tube 2 that will become the joint portion 21. At this time, the adhesive sheet is not attached to the portion of the surface of the inner tube 2 that will become the non-joint portion 22. Then, in an injection process, unvulcanized rubber for forming the main rubber 4 is injected into a mold in which the inner tube 2 and the outer tube 3 are set, and then, in a vulcanization process, the vibration-proof structure 1 is vulcanized and molded by the mold. In this case, during the vulcanization process, the main rubber 4 is bonded to the portion of the surface of the inner tube 2 to which the adhesive sheet is attached, where the joint portion 41 is formed, and is not bonded to the portion of the surface of the inner tube 2 to which the adhesive sheet is not attached, where the non-joint portion 42 is formed. Note that, for example, the adhesive sheet described in Japanese Patent No. 4681634 may be adopted as this adhesive sheet.
Another method for forming the joints 41 and non-joints 42 in the vulcanization process is as follows. First, in a surface processing step before the vulcanization step, a surface processing is performed by a laser on the part of the surface of the inner tube 2 that will become the joints 21, thereby forming a large number of microgrooves in that part of the inner tube 2. The part of the surface of the inner tube 2 that will become the non-joints 22 is not surface-processed. Then, in an injection step, unvulcanized rubber for forming the main rubber 4 is injected into a mold in which the inner tube 2 and the outer tube 3 are set, and then, in a vulcanization step, the vibration-proof structure 1 is vulcanized and molded by the mold. In this case, during the vulcanization step, the main rubber 4 enters the microgrooves in the surface-processed part of the surface of the inner tube 2 and is bonded to that part by an anchor effect, where the joints 41 are formed, and is not bonded to the part of the surface of the inner tube 2 that has not been surface-processed, where the non-joints 42 are formed. In addition, as this surface treatment, for example, those described in JP-A-2020-116862 and Japanese Patent No. 6489908 may be adopted.
However, the method for forming the bonded portion 41 and the non-bonded portion 42 may be a method other than the above.

In the vibration-proof structure 1, when the lubricant 5 is interposed between the non-jointed portion 22 of the inner tube 2 and the non-jointed portion 42 of the main rubber 4, it is preferable to carry out a lubricant injection process after the vulcanization process.
3 and 10 are diagrams for explaining an example of a lubricant injection step in manufacturing the vibration-proof structures 1 of the examples of FIGS. 1 and 8, respectively.
When performing the lubricant injection process, an injection hole H is formed in advance in the vibration-proof structure 1, as shown in Fig. 3 and Fig. 10, respectively. The injection hole H communicates the gap G between the non-jointed portion 22 of the inner tube 2 and the non-jointed portion 42 of the main rubber 4 with the outside of the vibration-proof structure 1. As in the examples of Fig. 3 and Fig. 10, the injection hole H may pass through the outer tube 3 and the main rubber 4 of the vibration-proof structure 1 between the gap G and the outside of the vibration-proof structure 1. In this case, any method may be used to form the injection hole H in advance, and examples include a method in which a through hole is formed in advance at a corresponding location of the outer tube 3, and a protrusion for forming the injection hole H is provided on a mold used during the injection process and the vulcanization process.
In the lubricant injection process, the lubricant 5 is injected from the outside through an injection hole H into the gap G between the non-joint portion 22 of the inner tube 2 and the non-joint portion 42 of the main rubber 4 .

When the lubricant injection step is performed as described above, the plug insertion step may be performed after the lubricant injection step.
4 and 11 are diagrams for explaining an example of performing a plug insertion step when manufacturing the vibration-proof structures 1 of the examples of FIGS. 1 and 8, respectively.
When performing the plug insertion step, as shown in Figures 4 and 11, the plug P is inserted into the injection hole H from outside the vibration-proof structure 1 to block the injection hole H. This makes it possible to prevent the lubricant 5 from leaking out to the outside.

After the vulcanization process, a drawing process may be performed. In the drawing process, the outer tube 3 is reduced in diameter by drawing the outer tube 3 inward in the radial direction. This causes the main rubber 4 to be in a compressed state, increasing the rigidity of the main rubber 4 and improving the durability of the main rubber 4.
When the lubricant injection step is performed as described above, it is preferable to perform the squeezing step after the lubricant injection step. In this case, as shown in FIG. 5, the injection hole H can be in an open state (FIG. 5(a)) before the squeezing step and in a closed state (FIG. 5(b)) after the squeezing step. Therefore, the injection hole H can be blocked by the squeezing step without performing the plug insertion step.
However, both the plug inserting step and the drawing step may be performed after the vulcanization step.
Although FIG. 5 shows the state where the drawing process is performed on the vibration-proof structure 1 of the example of FIG. 1, the drawing process may be similarly performed on the vibration-proof structure 1 of the example of FIG. 8 or other examples.

The above-mentioned drawing process may be performed on the vibration-proof structure 1 using a drawing machine or the like.
Alternatively, the above-mentioned drawing step may be performed by press-fitting the vibration-proof structure 1 onto the inner peripheral surface of an external cylindrical member (for example, the bracket cylindrical portion 711 of the bracket 71 in the example of FIG. 8).

When performing the drawing process as described above, the drawing rate may be the same (uniform) throughout the entire axial direction of the outer tube 3.

Alternatively, when the drawing process is performed as described above, the drawing rate at both axial end portions 31 of the outer cylinder 3 may be made greater than the drawing rate at the axial center portion 32 of the outer cylinder 3, as shown generally in Fig. 12. Fig. 12 is a drawing for explaining an example in which the drawing process is performed when manufacturing the vibration-proof structure 1 of the example of Fig. 8, with Fig. 12(a) showing generally the vibration-proof structure 1 before the drawing process and Fig. 12(b) showing generally the vibration-proof structure 1 after the drawing process.
In this case, in the vibration-proof structure 1 after the drawing process (FIG. 12(b)), the compression ratio at both axial ends of the main rubber 4 is higher than the compression ratio at the axial center of the main rubber 4.
This effectively improves the durability of both axial ends of the main rubber 4, and also suppresses a decrease in sliding property with respect to the inner tube 2 at the non-jointed portion 42 in the axial center portion of the main rubber 4. Since both axial ends of the main rubber 4 are connected to the inner tube 2 via a pair of joints 41, they are portions that expand and contract more than the axial center portion of the main rubber 4 during relative displacement of the inner tube 2, and therefore it is desirable for them to have a high compression ratio and therefore high durability. On the other hand, it is desirable for the axial center portion of the main rubber 4 to have a low compression ratio, since a high compression ratio would increase friction with the inner tube 2 at the non-jointed portion 42, which may increase sliding resistance.
A method for making the drawing ratio at both axial ends 31 of the outer tube 3 larger than that at the axial center 32 of the outer tube 3 in the drawing process may be, for example, as shown in the example of Fig. 12, such that the outer tube 3 has a shape with a larger diameter at both axial ends 31 than at the axial center 32 before the drawing process (Fig. 12(a)), and that the outer tube 3 has the same diameter over the entire axial direction after the drawing process (Fig. 12(b)) (i.e., the outer tube 3 consists only of straight portions 3S). In this case, as shown in the example of Fig. 12(a), the axial ends 31 of the outer tube 3 may extend gradually toward the outer periphery as they move outward in the axial direction before the drawing process (Fig. 12(a)).
Performing the drawing process so that the drawing rate at both axial ends 31 of the outer cylinder 3 is greater than the drawing rate at the axial center portion 32 of the outer cylinder 3 is particularly preferable when the vibration-proof structure 1 is provided on a strut mount 7 as in the example of Figure 8, since there is a tendency for movement in the prying direction to be large. However, a similar drawing process may also be performed on the vibration-proof structure 1 in the example of Figure 1 or other examples.

In the vibration-proof structure 1, when the outer tube 3 has a pair of vertical portions 3V (and possibly a pair of protruding portions 3E) in addition to the straight portion 3S (FIGS. 17 and 20), a bending process may be performed after the vulcanization process to bend both axial ends 31 of the outer tube 3, as illustrated diagrammatically in FIG. 19, thereby forming the pair of vertical portions 3V (and possibly a pair of protruding portions 3E).
Alternatively, in the vibration-proof structure 1, if the outer tube 3 has a pair of vertical portions 3V (and possibly a pair of protruding portions 3E) in addition to the straight portion 3S (Figures 17 and 20), the outer tube 3 may be formed in advance prior to the vulcanization process so that the outer tube 3 has a pair of vertical portions 3V (and possibly a pair of protruding portions 3E) in addition to the straight portion 3S, and then the vulcanization process may be carried out.

In each example described in this specification, the thickness of the outer tube 3 may be uniform, as in the examples shown in Figures 1, 7, 8, 15, 17, 20, and 30, or the thickness of the outer tube 3 may be non-uniform, as in the example shown in Figure 23.

In each of the examples described in this specification, as in the examples shown in Figures 1, 7, 8, 15, 17, and 20, the outer cylinder 3 may be constructed as a single unit, and may even consist of only one member.

Alternatively, in each example described in this specification, as in the fourth modified example shown in Fig. 21 to Fig. 27, the fifth modified example shown in Fig. 28, the sixth modified example shown in Fig. 29, and the seventh modified example shown in Fig. 30 to Fig. 31, the outer cylinder 3 may be composed of a plurality of partial outer cylinder members 3P arranged along the circumferential direction and constructed separately from each other. This configuration is particularly suitable when the vibration-proof structure 1 is press-fitted into the inner circumferential surface of the tubular part TP of the external member LA (e.g., a suspension link arm) as exemplified in Fig. 26 to Fig. 27. Each partial outer cylinder member 3P constitutes a part of the outer cylinder 3 in the circumferential direction, and thus has a partial cylindrical shape. Each partial outer cylinder member 3P may extend over approximately the same angular range (and thus the circumferential length) as each other. In the examples shown in Figures 21 to 27 and the examples shown in Figures 30 to 31, the outer tube 3 is composed of two partial outer tube members 3P, and each partial outer tube member 3P extends over an angular range of about 180°. In the example shown in Figure 28, the outer tube 3 is composed of three partial outer tube members 3P, and each partial outer tube member 3P extends over an angular range of about 120°. In the example shown in Figure 29, the outer tube 3 is composed of four partial outer tube members 3P, and each partial outer tube member 3P extends over an angular range of about 90°. The number of partial outer tube members 3P constituting the outer tube 3 may be any number.
In a natural state (FIGS. 21 to 23, 28, 29, and 30) in which no external force is acting on the vibration-proof structure 1, it is preferable that the multiple partial outer cylinder members 3P constituting the outer cylinder 3 are spaced apart from one another in the circumferential direction. In this case, gaps 3Q (also referred to as "division gaps 3Q" in this specification) exist between the partial outer cylinder members 3P.
In this case, it is preferable that the main body rubber 4 extends continuously around the entire circumference as in the examples shown in Figures 22, 28, 29, and 30. The inner circumferential surface of each partial outer tube member 3P is joined to the main body rubber 4 by adhesion or the like.
The multiple partial outer barrel members 3P constituting the outer barrel 3 are configured so that when the circumferential ends of each partial outer barrel member 3P come into contact with each other, thereby crushing each gap 3Q and making the outer barrel 3 continuous around the entire circumference (see FIG. 27(a)), the central axes O3P of each partial outer barrel member 3P coincide with each other (concentrate in one place). The central axis O3P of each partial outer barrel member 3P when the circumferential ends of each partial outer barrel member 3P come into contact with each other forms the central axis O3 of the outer barrel 3. The central axis O3P of the partial outer barrel member 3P is the central axis of the partial cylindrical shape formed by the partial outer barrel member 3P.
The outer diameter of the outer tube 3 (i.e., the diameter of the circumscribed cylinder of the outer peripheral surfaces of the multiple partial outer tube members 3P that make up the outer tube 3) when the vibration-proof structure 1 is in its natural state (Figs. 21 to 23, 28, 29, 30) is larger than the inner diameter of the tubular part TP of the external member LA. Moreover, the vibration-proof structure 1 is configured such that the circumferential ends of the partial outer tube members 3P come into contact with each other when the vibration-proof structure 1 is press-fitted into the tubular part TP of the external member LA (Figs. 26(b), 27).
In a vibration-proof structure 1 having such a configuration, as illustrated in Figures 26 to 27, when the vibration-proof structure 1 is pressed into the inner surface of the tubular portion TP of an external member LA (e.g., a suspension link arm), the main rubber 4 is compressed radially inward, while the multiple partial outer tube members 3P that make up the outer tube 3 are displaced radially inward and gradually approach each other in the circumferential direction, after which the circumferential ends of each partial outer tube member 3P come into contact with each other, thereby crushing each gap 3Q, and the outer tube 3 becomes continuous around the entire circumference (Figures 26 (b) and 27).
In this way, when the vibration-proof structure 1 is pressed into the tubular portion TP of the external member LA, the main body rubber 4 is in a compressed state, so that an initial strain can be applied to the main body rubber 4, which in turn improves the durability of the main body rubber 4 and suppresses rattling of the non-jointed portion 42.
5 and the like, there is a risk that the adhesion between the main body rubber 4 and the outer tube 3 may become easily peeled off due to the squeezing process, which is performed to squeeze the outer tube 3 made of one member. In this regard, when the outer tube 3 is made up of a plurality of partial outer tube members 3P as in this example, the squeezing process as described above is not required to put the main body rubber 4 into a compressed state, so that the risk that the adhesion between the main body rubber 4 and the outer tube 3 may become easily peeled off can be avoided.
In addition, before the vibration-proof structure 1 is press-fitted into the tubular portion TP of the external member LA, the outer diameter of the outer tube 3 when the circumferential ends of the partial outer tube members 3P come into contact with each other is set to be equal to or larger than the inner diameter of the tubular portion TP of the external member LA. It is preferable that before the vibration-proof structure 1 is press-fitted into the tubular portion TP of the external member LA, the outer diameter of the outer tube 3 when the circumferential ends of the partial outer tube members 3P come into contact with each other is set to be slightly larger than the inner diameter of the tubular portion TP of the external member LA. This makes it possible to make it difficult for the vibration-proof structure 1 to come out of the tubular portion TP of the external member LA when the vibration-proof structure 1 is press-fitted into the tubular portion TP of the external member LA.

In each example described in this specification, as in each example shown in FIG. 23 and FIG. 30, the outer peripheral surface of the inner tube 2 may have a pair of circumferential grooves 27 extending in the circumferential direction, each of which is located axially inward of the pair of joints 41 of the main rubber 4 (i.e., the non-jointed portion 22 of the outer peripheral surface of the inner tube 2). The pair of circumferential grooves 27 are located on both sides of the axial center of the vibration-proof structure 1. It is preferable that the pair of circumferential grooves 27 extend around the entire circumference and thus have an annular shape. As in each example shown in FIG. 23 and FIG. 30, the pair of circumferential grooves 27 may be located between the bulge-shaped portion 23 and the pair of joints 21 on the outer peripheral surface of the inner tube 2. It is preferable that the pair of circumferential grooves 27 are recessed toward the inner peripheral side from the pair of joints 21. 23 and 30, the non-bulge portion 24 on the outer circumferential surface of the inner cylinder 2 includes a circumferential groove 27 and a portion extending axially outward from the circumferential groove 27 in parallel with the axial direction.
The non-jointed portion 42 on the inner peripheral surface of the main rubber 4 has a pair of protrusions 44 configured to fit into the pair of circumferential grooves 27. The pair of protrusions 44 protrude toward the inner peripheral side and extend in the circumferential direction. It is preferable that the pair of protrusions 44 extend around the entire circumference and thus form an annular shape.
For example, when the inner tube 2 is displaced relative to the outer tube 3 in a direction perpendicular to the axis ( FIG. 24 ) or when the vibration-proof structure 1 is press-fitted into the tubular portion TP of the external member LA ( FIG. 26 ), the main rubber 4 tends to escape outward in the axial direction, particularly in the portion along the non-jointed portion 42, but according to this example, since the pair of protrusions 44 are fitted into the pair of circumferential grooves 27, it is possible to effectively prevent the main rubber 4 from shifting in the axial direction in the portion along the non-jointed portion 42. This makes it possible to prevent, for example, the main rubber 4 from shifting outward in the axial direction in the portion along the non-jointed portion 42 and buckling before the jointed portion 41, thereby improving durability.
23 and 30, when the vibration-proof structure 1 is in its natural state, it is preferable that the main rubber 4 extends continuously in the radial direction from the pair of protrusions 44 to the inner circumferential surface of the outer tube 3 in a pair of axial regions corresponding to the pair of protrusions 44 (and thus radially outward of the pair of protrusions 44). As a result, when the main rubber 4 is compressed between the inner tube 2 and the outer tube 3, for example, when the inner tube 2 is displaced relative to the outer tube 3 in the direction perpendicular to the axis (FIG. 24) or when the vibration-proof structure 1 is pressed into the tubular portion TP of the external member LA (FIG. 26), the compressive force in the direction perpendicular to the axis acting on the main rubber 4 can be applied more firmly to the pair of circumferential grooves 27, thereby further suppressing the main rubber 4 from shifting in the axial direction.

In each example described in this specification, as in the examples shown in Figures 23 and 30, the axial portion of the inner surface of the outer tube 3 (and thus the partial outer tube member 3P) corresponding to the bulge-shaped portion 23 of the inner tube 2 (i.e., the portion located radially outward of the bulge-shaped portion 23) may extend toward the inner circumference as it moves axially outward and may be curved so as to be convex toward the outer circumference.
In this case, as in the example shown in Figure 23, the thickness of the outer tube 3 may be made non-uniform and the outer peripheral surface of the outer tube 3 may extend parallel to the axial direction, or as in the example shown in Figures 30 to 31, the thickness of the outer tube 3 (and thus the partial outer tube member 3P) may be made uniform and the outer tube 3 itself may be curved by pressing or the like.

The vibration-proof structure, strut mount, and method for manufacturing the vibration-proof structure according to the present invention are suitable for application to a vehicle suspension system, for example, a McPherson strut suspension system. The vibration-proof structure and method for manufacturing the vibration-proof structure according to the present invention are suitable for use, for example, as a bush used in a link mechanism (such as a suspension link arm) of a vehicle suspension system (for example, a McPherson strut suspension system), or are suitable for use in a strut mount of a vehicle suspension system (for example, a McPherson strut suspension system).

1: Anti-vibration structure,
2: inner cylinder, 21: joint portion, 22: non-joint portion, 23: bulge-shaped portion, 24: non-bulge-shaped portion, 25: inner cylinder inner peripheral portion, 26: inner cylinder outer peripheral portion, 27: circumferential groove,
3: outer cylinder, 31: axial end portion, 32: axial center portion, 3S: straight portion, 3V: vertical portion, 3E: protruding portion, 3P: partial outer cylinder member, 3PO: central axis of partial outer cylinder member, 3Q: gap (division gap),
4: Main body rubber, 41: Joined portion, 42: Non-jointed portion, 43: Stopper portion, 44: Protrusion portion,
5: lubricant,
6: damper rod; 61: mounting portion; 62: step surface;
7: Strut mount,
71: bracket; 711: bracket tubular portion; 712: bracket flange portion; 713: central through hole; 715: bracket upper annular portion; 716: bracket lower annular portion;
72: bearings,
73: Spring seat,
8: Spring,
F1, F2: fasteners,
H: injection hole,
O2: central axis of the inner cylinder; O3: central axis of the outer cylinder (central axis of the vibration-proof structure);
G: Gap (non-joint gap),
P: plug,
LA: external member, TP: cylindrical part

Claims (11)

An inner cylinder;
An outer cylinder,
a main body rubber that connects the inner cylinder and the outer cylinder to each other;
A vibration-proof structure comprising:
The inner circumferential surface of the main rubber is
A pair of joints joined to an outer peripheral surface and/or an axial end surface of the inner cylinder over the entire circumference on both sides in the axial direction;
a non-jointed portion extending between the pair of jointed portions and contacting the inner cylinder without being joined thereto;
It has a vibration-proof structure. The outer cylinder has a straight portion extending parallel to an axial direction,
The vibration-proof structure according to claim 1 , wherein the straight portion extends from at least an axial center of the vibration-proof structure to an axial position of at least a portion of each of the pair of joints of the main rubber. The vibration-proof structure according to claim 1, wherein a lubricant is interposed between the inner tube and the non-jointed portion of the main rubber. The vibration-proof structure according to claim 1, wherein the outer peripheral surface of the inner cylinder has a bulge-shaped portion that protrudes toward the outer peripheral side. the pair of joint portions of the main rubber are joined over an entire circumference to a portion of the outer circumferential surface of the inner tube excluding the bulge-shaped portion and/or to the axial end surface of the inner tube,
The vibration-proof structure according to claim 4 , wherein the non-jointed portion of the main rubber is not joined to but is in contact with the bulge-shaped portion of the inner tube. The outer cylinder is made up of a plurality of partial outer cylinder members arranged in a circumferential direction and constructed separately from each other,
The vibration-proof structure according to claim 1 , wherein in a natural state in which no external force is acting on the vibration-proof structure, the partial outer cylinder members are spaced apart from each other in the circumferential direction. an outer circumferential surface of the inner tube has a pair of circumferential grooves extending in a circumferential direction, the pair of circumferential grooves being axially inward of the pair of joint portions of the main rubber;
The vibration-proof structure according to claim 1 , wherein the non-jointed portion of the main body rubber has a pair of protrusions configured to fit into the pair of circumferential grooves. The vibration-proof structure according to any one of claims 1 to 7, wherein the vibration-proof structure is configured as a bush used in a link mechanism of a suspension device. The vibration-proof structure according to any one of claims 1 to 7, wherein the vibration-proof structure is configured to be provided on a strut mount. A strut mount equipped with the vibration-proof structure described in any one of claims 1 to 7. A method for manufacturing a vibration-proof structure, comprising the steps of: manufacturing the vibration-proof structure according to any one of claims 1 to 7 through a vulcanization process.

Images