JP2020165478A - Vibration damping bushing - Google Patents

Abstract

To provide a vibration damping bushing in a novel structure capable of obtaining a hard spring property in a direction perpendicular to the axis and a soft spring property in a twisting direction in a compatible manner.SOLUTION: An expansion part 18 including a spherical outer peripheral surface is provided in an intermediate portion of an inner shaft member 12 in an axial direction, and the expansion part 18 and an outer cylinder member 14 are connected by a main body rubber elastic body 16. An intermediate member 26 is disposed in an outer periphery of the inner shaft member 12 and a main body part 28 in a spherical shell shape is provided in the intermediate member 26. A straight part 30 of which the curvature radius is enlarged is provided in an intermediate portion of a main body part 28 and the main body part 28 is separately disposed in an outer periphery of the expansion part 18. An axial length dimension L1 of the main body part 28 is made smaller than an axial length dimension L2 of the expansion part 18, and the main body rubber elastic body 16 between both ends of the main body part 28 in the axial direction and the expansion part 18 is defined as thin constriction parts 38.SELECTED DRAWING: Figure 2

Description

The present invention relates to a vibration-proof bushing applied to a suspension bush of an automobile or the like.

Conventionally, vibration-proof bushes such as suspension bushes used for attaching a suspension arm to a vehicle body in an automobile have been known. The anti-vibration bush has a structure in which the inner shaft member and the outer cylinder member are radially connected by a rubber elastic body of the main body.

By the way, the anti-vibration bush may be required to have a hard spring characteristic in the direction perpendicular to the axis. In order to satisfy such a requirement, for example, as in Japanese Patent Application Laid-Open No. 2014-092218 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2018-071664 (Patent Document 2), between the inner shaft member and the outer cylinder member in the radial direction. A structure in which an intermediate member is provided is also known.

Japanese Unexamined Patent Publication No. 2014-092218 Japanese Unexamined Patent Publication No. 2018-0716664

However, as a result of examination by the present inventor, in the structure disclosed in Patent Document 1, there is a case where the durability of the main body rubber elastic body cannot be sufficiently ensured with respect to the input in the prying direction. That is, in the structure of Patent Document 1, since both the inner shaft member and the intermediate member have a cross-sectional shape extending linearly in the axial direction, the inner shaft member and the intermediate member have a cross-sectional shape that extends linearly in the axial direction. The main body rubber elastic body is easily compressed locally between them, and there is still room for improvement in the durability of the main body rubber elastic body.

In Patent Document 1, a breakage portion is provided in the intermediate member to partially shorten the axial length dimension of the intermediate member, so that the inner cylinder is displaced in the prying direction with respect to the outer cylinder. , The amount of compression deformation of the main body rubber elastic body is reduced. However, if the axial length of the intermediate member is reduced by the cutout portion, the effect of increasing the static spring constant in the direction perpendicular to the axis by the intermediate member is reduced, and the rigid spring characteristic in the direction perpendicular to the axis is maintained. hard.

Further, in Patent Document 2, a spherical convex portion protruding outward in the radial direction is provided in the center of the axial direction of the shaft member, and the intermediate cylinder is formed to be curved corresponding to the outer peripheral surface of the convex portion. There is. According to this, the rubber elastic body is less likely to be compressed between the shaft member and the intermediate cylinder with respect to the input in the prying direction, and the soft spring characteristics and durability in the prying direction can be improved.

However, in the structure of Patent Document 2, not only the spring characteristics in the prying direction but also the spring characteristics in the direction perpendicular to the axis are softened. That is, when a load in the direction perpendicular to the axis is input to the anti-vibration bush of Patent Document 2, the rubber elastic body between the convex portion of the shaft member and the intermediate cylinder becomes the outer peripheral surface and the intermediate cylinder of the convex portion as a curved surface. It becomes easy to escape to the outside in the axial direction along the inner peripheral surface of the. As a result, it is difficult for the rubber elastic body to exhibit the hard spring characteristics due to the compression spring component, and the spring characteristics in the direction perpendicular to the axis tend to be soft, and it may be difficult to obtain the required spring characteristics.

An object of the present invention is to provide a vibration-proof bush having a novel structure capable of obtaining both a hard spring characteristic in the direction perpendicular to the axis and a soft spring characteristic in the prying direction.

Hereinafter, preferred embodiments for grasping the present invention will be described, but each of the embodiments described below is described as an example, and not only can be appropriately combined with each other and adopted, but also described in each embodiment. The plurality of components of the above can be recognized and adopted independently as much as possible, and can be appropriately adopted in combination with any of the components described in another embodiment. Thereby, in the present invention, various other aspects can be realized without being limited to the aspects described below.

The first aspect is a vibration-proof bush in which an inner shaft member and an outer cylinder member are radially connected by a rubber elastic body of the main body, and a spherical outer peripheral surface is provided at an axially intermediate portion of the inner shaft member. A bulging portion is provided, and the bulging portion and the outer cylinder member are connected by the main body rubber elastic body, and an intermediate member is arranged on the outer periphery of the inner shaft member, and the intermediate member is provided. Is provided with a spherical shell-shaped main body portion, and a straight-shaped portion having a large radius of curvature is provided in an axially intermediate portion of the main body portion, and the main body portion is the outer circumference of the bulging portion. The axial length dimension of the main body portion is made smaller than the axial length dimension of the bulging portion, and both ends in the axial direction of the main body portion and the bulging portion are The main body rubber elastic body between the two is a thin-walled narrowed portion.

According to the anti-vibration bush having a structure according to this aspect, the spring constant in the direction perpendicular to the axis can be set large by providing the intermediate member between the inner shaft member and the outer cylinder member. Therefore, when a hard spring characteristic is required in the direction perpendicular to the axis, the required characteristic can be easily satisfied. Moreover, the main body portion of the spherical shell-shaped intermediate member is provided with a straight-shaped portion in the intermediate portion in the axial direction. As a result, when a load in the direction perpendicular to the axis is input between the inner shaft member and the outer cylinder member, the rubber elastic body of the main body is efficiently compressed in the straight portion, and the hard spring characteristics due to the compression spring component are efficiently performed. Can be obtained.

In the intermediate member, the spherical shell-shaped main body portion is arranged apart from the outer periphery of the bulging portion provided on the inner shaft member. Therefore, when the inner shaft member is displaced relative to the outer cylinder member and the intermediate member due to the input in the prying direction, the main body rubber elastic body is formed between the bulging portion of the inner shaft member and the main body portion of the intermediate member. Local compression is unlikely to occur. As a result, the expression of the hard spring characteristic by the compression spring of the rubber elastic body of the main body is suppressed, and the spring can be lowered in the prying direction.

The axial length of the main body is smaller than the axial length of the bulge, and both ends of the main body in the axial direction approach the bulge outward in the axial direction. ing. The main body rubber elastic body provided between both ends in the axial direction of the main body portion and the bulging portion is a thin-walled constricted portion. As a result, when the rubber elastic body of the main body located between the straight part and the bulging part of the main body is compressed in the direction perpendicular to the axis, the deformation that bulges outward in the axial direction due to the narrowed part having a large strain is restricted. It is hard to escape to the outside in the axial direction. As a result, the compression spring component becomes more dominant with respect to the load input in the direction perpendicular to the axis, and a hard spring characteristic can be obtained in the direction perpendicular to the axis.

In the second aspect, in the anti-vibration bush described in the first aspect, the thickness dimension of the narrowed portion of the main body rubber elastic body is such that the straight portion of the intermediate member and the bulge of the inner shaft member. It is made smaller than the thickness dimension of the main body rubber elastic body between the protruding portion.

According to the anti-vibration bush having a structure according to this embodiment, the strain of the narrowed portion is compressed between the straight portion of the intermediate member and the bulging portion of the inner shaft member with respect to the load input in the direction perpendicular to the axis. It becomes larger than the strain of the rubber elastic body of the main body. As a result, the rubber elastic body of the main body, which is compressed between the straight portion and the bulging portion, is restrained from being deformed outward in the axial direction at the narrowed portion, and it becomes easier to set the spring characteristics in the direction perpendicular to the axis more rigidly. ..

Further, since the portion of the main body rubber elastic body located between the straight portion and the bulging portion is thicker than the narrowed portion, the spring characteristic with respect to the input in the prying direction is softened.

The third aspect is the anti-vibration bush described in the first or second aspect, wherein the intermediate member is composed of a pair of divided bodies facing each other in the radial direction, and each of the divided bodies has the main body portion. Protruding portions protruding outward in the axial direction are provided at two locations in the circumferential direction, and the width dimension between the protruding portions of each of the divided bodies is the width dimension of the inner shaft member at least at the base end portion of the protruding portion. It is made smaller than.

According to the anti-vibration bush having a structure according to this aspect, at least at the base end portion of the protruding portion, the protruding portion and the inner shaft member are arranged at overlapping positions in the direction perpendicular to the axis. Therefore, when the load is input in the direction perpendicular to the axis, the rubber elastic body of the main body is compressed even between the protrusion and the inner shaft member, and a harder spring characteristic can be realized in the direction perpendicular to the axis.

A fourth aspect is the anti-vibration bush described in any one of the first to third aspects, wherein the outer cylinder member has a diameter reduced to the inner peripheral side toward the main body portion of the intermediate member. The diaphragm-shaped portion is provided on the outer side in the axial direction from the main body portion.

According to the anti-vibration bush having a structure according to this embodiment, the outer cylinder member is provided with a throttle-shaped portion on the outer side in the axial direction from the main body portion of the intermediate member, so that a softer spring characteristic is realized in the prying direction. It becomes easy to be done.

According to the present invention, in the anti-vibration bush, it is possible to obtain both a hard spring characteristic in the direction perpendicular to the axis and a soft spring characteristic in the prying direction.

It is a right side view which shows the suspension bush as the 1st Embodiment of this invention, and corresponds to the right side surface of FIG. II-II sectional view of FIG. Section III-III sectional view of FIG. IV-IV sectional view of FIG. Top view of the split body constituting the suspension bush shown in FIG. Right side view of the split body shown in FIG. VII-VII sectional view of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In FIGS. 1 to 4, a suspension bush 10 for an automobile is shown as a first embodiment of a vibration-proof bush having a structure according to the present invention. As shown in FIG. 2, the suspension bush 10 has a structure in which the inner shaft member 12 and the outer cylinder member 14 are radially connected by the main body rubber elastic body 16. In the following description, as a general rule, the vertical direction means the vertical direction in FIG.

The inner shaft member 12 is a highly rigid member made of metal or a hard synthetic resin. The inner shaft member 12 has a substantially cylindrical shape with a thick wall and a small diameter. The inner shaft member 12 includes a bulging portion 18 at an intermediate portion in the axial direction. The bulging portion 18 is provided so as to project toward the outer periphery in the radial direction, and the outer peripheral surface is a spherical convex curved surface. The bulging portion 18 of the present embodiment is provided at the center of the inner shaft member 12 in the axial direction, but the bulging portion 18 is provided at an intermediate portion off the center of the inner shaft member 12 in the axial direction. You may.

Like the inner shaft member 12, the outer cylinder member 14 is a highly rigid member made of metal, a hard synthetic resin, or the like. The outer cylinder member 14 has a thin-walled large-diameter substantially cylindrical shape. A flange-shaped portion 20 extending toward the outer circumference is provided at one end of the outer cylinder member 14 in the axial direction. The other end of the outer cylinder member 14 in the axial direction is reduced in diameter by the tapered portion 22.

The inner shaft member 12 is inserted through the outer cylinder member 14, and the inner shaft member 12 and the outer cylinder member 14 are radially connected by the main body rubber elastic body 16. The main body rubber elastic body 16 has a substantially cylindrical shape, the inner peripheral surface of the main body rubber elastic body 16 is fixed to the outer peripheral surface of the inner shaft member 12, and the outer peripheral surface of the main body rubber elastic body 16 is an outer cylinder member. It is fixed to the inner peripheral surface of 14. The bulging portion 18 of the inner shaft member 12 is arranged in a state of being inserted into the inner circumference of the outer cylinder member 14, and the main body rubber elastic body 16 is arranged between the bulging portion 18 and the outer cylinder member 14 in the radial direction. Is provided. The main body rubber elastic body 16 is fixed to the entire surface of the bulging portion 18. The main body rubber elastic body 16 is fixed to the inner peripheral surface of the drawn portion 22 of the outer cylinder member 14.

A stopper rubber 24 is fixed to the flange-shaped portion 20 of the outer cylinder member 14. The stopper rubber 24 is integrally formed with the main body rubber elastic body 16 and is fixed to the axial outer surface of the flange-shaped portion 20.

An intermediate member 26 is fixed to the main body rubber elastic body 16. The central portion of the intermediate member 26 in the axial direction is a spherical shell-shaped main body 28 that is convex toward the outer circumference as a whole. The main body 28 has a straight portion 30 whose central portion in the axial direction extends linearly in the axial direction, and both sides of the straight portion 30 in the axial direction have a tapered shape whose diameter becomes smaller toward the outside in the axial direction. It is said to be parts 32 and 32. The straight portion 30 has a linear cross-sectional shape extending in the axial direction with a large radius of curvature. The tapered portion 32 has a linear cross-sectional shape that extends at an angle with respect to the straight portion 30, and is smoothly continuous with the straight portion 30 by a connecting portion having a curved cross section.

The intermediate member 26 of the present embodiment is composed of a pair of divided bodies 34, 34. As shown in FIGS. 5 to 7, each of the divided bodies 34 has a hemispherical shell shape constituting the main body 28. Further, each of the divided bodies 34 is provided with four protrusions 36, 36, 36, 36. The projecting portion 36 has a plate shape, and projects toward both sides in the axial direction at both end portions in the circumferential direction of the divided body 34. Each protruding portion 36 has a width dimension of less than 1/4 of the divided body 34 in the circumferential direction. The protrusions 36 are symmetrical to each other, but may have different shapes that are asymmetrical to each other.

As shown in FIGS. 2 to 4, the pair of divided bodies 34, 34 are arranged on the same circumference between the inner shaft member 12 and the outer cylinder member 14 in the radial direction, and are arranged so as to face each other in the radial direction. It is fixed to the rubber elastic body 16 of the main body. As a result, the intermediate member 26 having the main body portion 28 having a spherical shell shape as a whole is composed of the pair of divided bodies 34 and 34. The intermediate member 26 is arranged on the outer periphery of the inner shaft member 12, and is arranged between the inner shaft member 12 and the outer cylinder member 14 in the radial direction. The main body 28 of the intermediate member 26 is arranged apart from the outer periphery of the bulging portion 18 of the inner shaft member 12. As shown in FIGS. 3 and 4, the pair of divided bodies 34, 34 have ends separated from each other in the circumferential direction. In the intermediate member 26, the main body 28 and the base end portions of the protruding portions 36 are fixed to the main body rubber elastic body 16 in a state of being embedded, and the tip portion of each protruding portion 36 is shafted from the main body rubber elastic body 16. It protrudes outward in the direction and is exposed to the outside.

As shown in FIG. 2, the main body portion 28 of the intermediate member 26 has an axial length dimension L1 smaller than the axial length dimension L2 of the bulging portion 18 of the inner shaft member 12. The axial center of the main body 28 substantially coincides with the axial center of the bulge 18. As a result, the entire main body 28 is located apart from the outer periphery of the bulge 18.

In the main body 28 of the intermediate member 26, the straight portion 30 is located substantially at the center between the bulging portion 18 of the inner shaft member 12 and the outer cylinder member 14 in the radial direction. The tapered portions 32, 32 extending from the straight portion 30 to both sides in the axial direction approach the bulging portion 18 of the inner shaft member 12 in the outward direction in the axial direction, and the inner shaft member 12 and the outer cylinder It is located on the inner peripheral side of the center between the radial directions of the members 14. As a result, the distance t1 from the bulging portion 18 to both ends of the tapered portion 32 in the axial direction is made smaller than the distances t2 and t3 from the bulging portion 18 to the straight portion 30. As a result, in the main body rubber elastic body 16, the portions provided between the bulging portion 18 and the axially outer ends of the tapered portions 32 and 32 are formed as thin-walled narrowed portions 38, respectively. Further, in the main body rubber elastic body 16, the portion located axially inside the narrowed portions 38, 38 between the main body portion 28 of the intermediate member 26 and the bulging portion 18 of the inner shaft member 12 is the center of the thick wall. It is said to be a thick portion 40. The thickness dimension t1 of the narrowed portion 38 is smaller than the thickness dimension t2 of the axially central portion of the central thick portion 40. The distance t2 from the bulging portion 18 to the center of the straight portion 30 in the axial direction is smaller than the distance t3 from the bulging portion 18 to both ends of the straight portion 30 in the axial direction.

In the cross section of the base end portion of the protruding portion 36 shown in FIG. 4, the distance D between the protruding portions 36, 36 at both ends in the circumferential direction in each of the divided bodies 34 is made smaller than the width dimension W of the inner shaft member 12. There is. As a result, at least the base end portion of the protruding portion 36 overlaps with the inner shaft member 12 in the projection in the direction perpendicular to the axis (vertical direction in FIG. 4).

The throttle-shaped portion 22 of the outer cylinder member 14 is arranged outward in the axial direction with respect to the main body portion 28 of the intermediate member 26. Preferably, the inner peripheral surface of the drawn portion 22 is arranged so as to face the outer peripheral surface of the bulging portion 18 of the inner shaft member 12.

For example, the suspension bush 10 having such a structure is attached to the vehicle by attaching the inner shaft member 12 to a vehicle body (not shown) and press-fitting and fixing the outer cylinder member 14 to the arm eye of the suspension arm (not shown). In the vehicle-mounted state, the load in the vertical direction and the load in the prying direction are mainly input to the suspension bush 10.

When a load in the vertical direction is input, the inner shaft member 12 and the outer cylinder member 14 are relatively displaced in the vertical direction, and the main body rubber elastic body 16 between the inner shaft member 12 and the outer cylinder member 14 moves up and down. It compresses and deforms on one side of the direction. As a result, the hard spring characteristics due to the compression spring component are exhibited, and excellent running performance and load bearing performance can be realized.

In particular, an intermediate member 26 is arranged between the inner shaft member 12 and the outer cylinder member 14 in the vertical direction, and between the inner shaft member 12 and the intermediate member 26 and between the intermediate member 26 and the outer cylinder member 14, respectively. The substantially free length of the main body rubber elastic body 16 is reduced. As a result, the compressibility of the main body rubber elastic body 16 with respect to the input becomes large, and the hard spring characteristic is easily exhibited with respect to the input in the vertical direction.

Further, the straight portion 30 provided on the main body portion 28 of the intermediate member 26 extends substantially parallel to the inner peripheral surface of the outer cylinder member 14. As a result, the main body rubber elastic body 16 is efficiently compressed between the straight portion 30 and the outer cylinder member 14, and the hard spring characteristics due to the compression spring component are more effectively exhibited.

Further, the straight portion 30 of the intermediate member 26 is located substantially at the center between the inner shaft member 12 and the outer cylinder member 14 in the radial direction. As a result, in response to the input in the vertical direction, the portion of the main body rubber elastic body 16 located on the inner peripheral side and the portion located on the outer peripheral side of the straight portion 30 are substantially arranged in series in the vertical direction. It is compressed at the same compression ratio. As a result, it is easy to set a large spring constant in the vertical direction as compared with the case where the main body rubber elastic body 16 is significantly thicker than the other on either the inner peripheral side or the outer peripheral side of the intermediate member 26. Become.

The portions of the main body rubber elastic body 16 located between the tapered portions 32 and 32 and the bulging portions 18 are thin-walled narrowed portions 38, respectively. As a result, the narrowed portion 38 is compressed with a larger compression rate with respect to the input in the vertical direction, and a hard spring characteristic can be realized.

The central thick portion 40 of the main body rubber elastic body 16 tends to bulge outward in the axial direction according to the Poisson's ratio when compressed in the vertical direction, but on both sides in the axial direction of the central thick portion 40. By providing the narrowed portions 38, 38, bulging (escape) outward in the axial direction is prevented. That is, when the main body rubber elastic body 16 is compressed in the vertical direction, the strain of the narrowed portions 38, 38 becomes larger than the strain of the central thick portion 40. In this way, by tightening the narrowed portions 38, 38 on both lateral sides of the central thick portion 40 in the axial direction, the escape of the central thick portion 40 to the lateral side in the axial direction is restricted by the narrowed portions 38, 38. .. As a result, the spring constant of the central thick portion 40 in the vertical direction becomes large, and a harder spring characteristic in the vertical direction can be realized.

The intermediate member 26 is provided with a plurality of protruding portions 36, and these protruding portions 36 face the inner shaft member 12 on the lateral side in the axial direction from the bulging portion 18. Thereby, a harder spring characteristic can be realized in the vertical direction. In the present embodiment, the distance D between the base end portions of the two projecting portions 36, 36 provided apart from each other in the circumferential direction in each of the divided bodies 34 is narrower than the width dimension W of the inner shaft member 12. As a result, the protruding portion 36 overlaps the inner shaft member 12 at least in part in the vertical projection, and the main body rubber elastic body 16 is compressed between the inner shaft member 12 and the protruding portion 36 at the time of input in the vertical direction. Therefore, harder spring characteristics are exhibited.

Since the spherical shell-shaped main body 28 provided on the intermediate member 26 is arranged apart from the outer periphery of the bulging portion 18 of the inner shaft member 12, the inner shaft member 12 and the main body are arranged when a load in the prying direction is input. It is difficult for the main body rubber elastic body 16 to be compressed between the portions 28. Therefore, the increase in spring due to the compression spring is suppressed with respect to the input in the prying direction, and a softer spring characteristic can be obtained.

Further, when the relative displacement amount of the inner shaft member 12 and the intermediate member 26 increases due to the input in the prying direction, the narrowed portion 38 of the main body rubber elastic body 16 is compressed, and the spring constant increases non-linearly. As a result, while achieving the initial low spring characteristics with respect to the input in the prying direction, when the input is large, the amount of deformation of the main body rubber elastic body 16 is limited by the non-linear and hard spring characteristics, and the main body rubber The durability of the elastic body 16 is improved.

Since the distance D between the base ends of the projecting portions 36, 36 adjacent to each other in the circumferential direction is smaller than the width dimension W of the inner shaft member 12, there is a space between the protruding portion 36 and the inner shaft member 12 with respect to the prying input. The main body rubber elastic body 16 is compressed. As a result, even when inputting in the prying direction, the static spring characteristics are adjusted so as not to be too soft due to a certain amount of compression spring component. The spring characteristics in the prying direction can be easily adjusted by appropriately adjusting the difference between the distance D between the base ends of the protrusions 36 and 36 and the width dimension W of the inner shaft member 12.

The outer cylinder member 14 is provided with a throttle-shaped portion 22, and the throttle-shaped portion 22 is arranged outside the main body portion 28 of the intermediate member 26 in the axial direction. As a result, the escape of the main body rubber elastic body 16 outward in the axial direction with respect to the input in the vertical direction is also reduced by the throttle-shaped portion 22, and it becomes easier to obtain a hard spring characteristic in the vertical direction. For input in the prying direction, the compression spring of the main body rubber elastic body 16 is reduced between the bulging portion 18 of the inner shaft member 12 and the drawn portion 22 of the outer cylinder member 14, and the spring is soft in the prying direction. The characteristics can be obtained.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited by the specific description thereof. For example, the intermediate member does not necessarily have to be composed of a pair of divided bodies 34, 34, and may be, for example, a spherical shell shape continuous all around.

In the embodiment, the tapered portion 32 of the main body portion 28 of the intermediate member 26 has a substantially flat cross-sectional shape with almost no change in curvature, but for example, even if the cross-sectional shape has a large change in curvature. good. Further, the straight portion 30 of the main body portion 28 does not need to have a strictly linear cross-sectional shape as long as the curvature is smaller than the curvature of the cross section of the entire main body portion 28 having a spherical shell shape. , Curvature of cross-sectional shape is allowed.

The protrusion 36 provided on the intermediate member 26 of the embodiment is not essential. For example, the intermediate member may be composed of only the main body 28. Further, when the protrusions 36 are provided, the number of the protrusions 36 is not limited.

The arrangement of the protruding portion 36 is not limited to the circumferential end portion of the divided body 34, and may be arranged, for example, in the circumferential direction of the divided body 34 and inside the end portion. In this case, the area where the protruding portion 36 and the inner shaft member 12 overlap in the direction perpendicular to the axis becomes large, and the springs in the direction perpendicular to the axis and the twisting direction become stiff. Therefore, the position of the protruding portion 36 is appropriately set in the circumferential direction. It is possible to tune the spring characteristics by adjusting.

In the above embodiment, the throttle-shaped portions 22 are provided only at one end in the axial direction of the outer cylinder member 14, but the throttle-shaped portions 22 can also be provided on both sides of the outer cylinder member 14 in the axial direction. ..

10 Suspension bush (vibration-proof bush)
12 Inner shaft member 14 Outer cylinder member 16 Main body rubber elastic body 18 Protruding part 20 Flange-shaped part 22 Squeezed part 24 Stopper rubber 26 Intermediate member 28 Main body part 30 Straight-shaped part 32 Tapered part 34 Divided body 36 Protruding part 38 Stenosis Part 40 Central thick part

Claims (4)

A vibration-proof bush in which the inner shaft member and the outer cylinder member are radially connected by a rubber elastic body of the main body.
A bulging portion having a spherical outer peripheral surface is provided at an axially intermediate portion of the inner shaft member, and the bulging portion and the outer cylinder member are connected by the main body rubber elastic body.
An intermediate member is arranged on the outer periphery of the inner shaft member, the intermediate member is provided with a spherical shell-shaped main body portion, and the radius of curvature is increased in the axial intermediate portion of the main body portion. A straight portion is provided, and the main body portion is arranged apart from the outer periphery of the bulging portion.
The axial length dimension of the main body portion is made smaller than the axial length dimension of the bulging portion, and the main body rubber elastic body between the axially both ends of the main body portion and the bulging portion. Anti-vibration bush that is said to be a thin-walled constriction. The thickness dimension of the narrowed portion of the main body rubber elastic body is made smaller than the thickness dimension of the main body rubber elastic body between the straight portion of the intermediate member and the bulging portion of the inner shaft member. The anti-vibration bush according to claim 1. The intermediate member is composed of a pair of divided bodies facing each other in the radial direction.
Each of the divided bodies is provided with protrusions protruding outward in the axial direction from the main body at two locations in the circumferential direction, and at least at the base end of the protrusions, the width between the protruding portions of the divided bodies. The anti-vibration bush according to claim 1 or 2, wherein the dimension is smaller than the width dimension of the inner shaft member. Claims 1 to 3 that the outer cylinder member is provided with a throttle-shaped portion of the intermediate member whose diameter is reduced inward toward the main body portion in the axial direction with respect to the main body portion. The anti-vibration bush according to any one item.

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