Anti-Vibration Bushings

Abstract

To achieve reduction of spring rigidity for input vibration acting in a twisting direction.SOLUTION: In a vibration control bush, an expansion part 17 expanding to a radial outer side is formed at a portion which is enclosed from the radial outer side by a slide cylinder 13 on an outer peripheral surface of an inner cylinder 11. The vibration control bush includes: a first elastic body 14 which connects an outer peripheral surface of the expansion part with an inner peripheral surface of the slide cylinder; second elastic bodies 15, making a pair, which respectively connect portions located at both sides sandwiching the expansion part in an axial direction with an inner peripheral surface of an outer cylinder 12 over an entire circumferential length on the outer peripheral surface of the inner cylinder; outer engagement members 18 each of which protrudes from the inner peripheral surface of the outer cylinder to the radial inner side; and inner engagement members 19 each of which is provided at the axial inner side relative to the outer engagement member and protrudes from the outer peripheral surface of the inner cylinder to the radial outer side. Each second elastic body extends to the axial outer side in a direction from the radial inner side toward the outer side, connects the inner engagement member with the outer engagement member in the axial direction, and is spaced apart from the slide cylinder and the expansion part to the axial outer side.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vibration-isolating bushing. [Background technology]

[0002] Conventionally, there has been known a vibration-damping bushing comprising an inner tube connected to either a vibration generating part or a vibration receiving part, an outer tube connected to the other and surrounding the inner tube from the outside in the radial direction, and a sliding tube slidably fitted into the outer tube, wherein a spherical bulge that bulges outward in the radial direction is formed on the outer surface of the inner tube, and a concave spherical recess into which the bulge is slidably fitted is formed on the inner surface of the sliding tube, and a pair of elastic bodies that connect the inner surface of the outer tube to each portion located on either side of the bulge in the axial direction along the central axis of the inner tube, and the inner surface of the outer tube, separately over their entire circumferential length. In this vibration-damping bushing, when vibration in the twisting direction is input, the inner tube and outer tube are displaced relative to each other so that their respective central axes intersect with each other, the elastic body elastically deforms and the outer surface of the bulge slides against the inner surface of the recessed portion, and when vibration in the axial direction is input, the elastic body elastically deforms in response to the relative displacement of the inner tube and outer tube, and the sliding tube slides against the inner surface of the outer tube. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-129460 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the conventional vibration-isolating bushings, there is a problem in that it is difficult to reduce the spring resistance against input vibration in the twisting direction.

[0005] The present invention has been made in consideration of the above circumstances, and has an object to provide a vibration-isolating bushing that can reduce spring resistance against input vibration in the twisting direction. [Means for solving the problem]

[0006] In order to solve the above problems and achieve the above object, the vibration-proof bushing of the present invention comprises an inner tube connected to either a vibration generating section or a vibration receiving section, an outer tube connected to the other and surrounding the inner tube from the outside in the radial direction, and a sliding tube slidably fitted into the outer tube, wherein a bulge portion bulging outward in the radial direction is formed on the outer peripheral surface of the inner tube in a portion surrounded from the outside in the radial direction by the sliding tube, a first elastic body connecting the outer peripheral surface of the bulge portion and the inner peripheral surface of the sliding tube, and the inner peripheral surface of the outer tube over the entire circumferential length thereof; an outer locking member protruding radially inward from the inner peripheral surface of the outer tube; and an inner locking member provided on the inside, closer to the bulge in the axial direction than the outer locking member, protruding radially outward from the outer peripheral surface of the inner tube, wherein the second elastic body extends outward in the axial direction away from the bulge as it moves from the radial inside to the outside, connects the inner locking member and the outer locking member in the axial direction, and is spaced outward in the axial direction from the sliding tube and the bulge.

[0007] According to this invention, since the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder are connected to the first elastic body and the second elastic body, when the inner cylinder and the outer cylinder are relatively displaced so that their central axes cross each other and a vibration in the prying direction is input, the first elastic body and the second elastic body are elastically deformed. At this time, the pair of second elastic bodies sandwiching the bulge in the axial direction extend from the inside to the outside in the radial direction toward the outside in the axial direction and connect the inner locking member and the outer locking member in the axial direction, so that the second elastic body can be shear-deformed by the load in the prying direction, and it is possible to reduce the springiness against the input vibration in the prying direction. Since a first elastic body is provided connecting the outer peripheral surface of the bulge portion and the inner peripheral surface of the sliding tube, when radial vibration is input, the first elastic body and the second elastic body elastically deform, causing the outer tube and the inner tube to elastically displace relative to each other in the radial direction, making it easy to adjust the spring against the input radial vibration. Since the second elastic body is spaced axially outward from the sliding tube and the bulge portion, when axial vibrations and vibrations around the central axis are input, the second elastic body elastically deforms smoothly in accordance with the relative displacement of the inner tube and the outer tube, while the sliding tube slides along the inner surface of the outer tube.

[0008] The second elastic body may be provided in a state in which a compressive force is applied in the axial direction from the inner engaging member and the outer engaging member.

[0009] Since the second elastic body is provided with a compressive force applied in the axial direction, it is possible to prevent the relative positions in the axial direction between the outer tube and the inner tube and the sliding tube from shifting before and after the load input, and it is also possible to ensure the durability of the second elastic body.

[0010] The outer locking member and the inner locking member may extend inward in the axial direction as they move from the inner side to the outer side in the radial direction.

[0011] Since the outer locking member and the inner locking member extend inward in the axial direction as they move from the inner side to the outer side in the radial direction, the second elastic body can be reliably subjected to shear deformation in response to a load in the prying direction.

[0012] A recess for accommodating a lubricant may be formed in at least one of an outer circumferential surface of the sliding cylinder and an inner circumferential surface of the outer cylinder.

[0013] Since a storage recess for storing a lubricant is formed on at least one of the outer peripheral surface of the sliding cylinder and the inner peripheral surface of the outer cylinder, it becomes possible to retain the lubricant between the outer peripheral surface of the sliding cylinder and the inner peripheral surface of the outer cylinder, thereby maintaining smooth sliding of the sliding cylinder for a long period of time. Effect of the Invention

[0014] According to this invention, it is possible to reduce spring resistance against input vibration in the twisting direction. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a vertical cross-sectional view of a vibration-isolating bushing shown as an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, one embodiment of the vibration-isolating bushing will be described with reference to FIGS. The vibration-damping bush 1 comprises an inner tube 11 connected to either the vibration generating part or the vibration receiving part, and an outer tube 12 connected to the other, a sliding tube 13, a first elastic body 14, a second elastic body 15, an outer locking member 18, and an inner locking member 19.

[0017] The vibration-isolating bushing 1 is used, for example, as a suspension bushing or engine mount for an automobile, or as a mount for industrial machinery installed in a factory. When the vibration-damping bush 1 is used, for example, as a suspension bush for an automobile, the inner tube 11 is clamped on both axial sides by a bracket (not shown) of a suspension member or the like, and the inner tube 11 is fixed to the bracket using a fastening member (not shown) such as a bolt inserted into the inner tube 11, and the outer tube 12 is fixed to the holder by pressing the outer tube 12 into the inside of, for example, an attachment holder (not shown) of a link member.

[0018] Hereinafter, the direction along the central axis O of the inner cylinder 11 will be referred to as the axial direction. In addition, in a plan view of the vibration-proof bushing 1 from the axial direction, the direction intersecting the central axis O will be referred to as the radial direction, and the direction going around the central axis O will be referred to as the circumferential direction.

[0019] The axial center portions of the inner cylinder 11, the outer cylinder 12, the sliding cylinder 13, and the first elastic body 14 coincide with each other. The vibration-proof bushing 1 has a symmetrical shape with respect to a line L passing through the axial center portion in a vertical cross-sectional view along one of the axial and radial directions. Hereinafter, the side approaching the straight line L along the axial direction will be referred to as the inner side in the axial direction, and the side away from the straight line L along the axial direction will be referred to as the outer side in the axial direction.

[0020] The outer cylinder 12 is formed of, for example, a metal material. The outer cylinder 12 surrounds the inner cylinder 11 from the outside in the radial direction. The outer cylinder 12 is arranged coaxially with the central axis O. A step portion 12a facing outward in the axial direction is formed on both axial ends of the inner peripheral surface of the outer cylinder 12. A crimped portion 12b bent toward the inside in the radial direction is formed on an end edge of the outer cylinder 12 located axially outward from the step portion 12a. The step portion 12a and the crimped portion 12b extend continuously over the entire circumferential length. The step portion 12a and the crimped portion 12b face each other in the axial direction.

[0021] The sliding cylinder 13 is slidably fitted in the outer cylinder 12. The sliding cylinder 13 is formed of a low-friction material such as polyacetal. The sliding cylinder 13 is disposed coaxially with the central axis O. The sliding cylinder 13 is provided in the axial center of the outer cylinder 12. A strip-shaped restricting portion 13a is formed on each of both axial ends of the inner peripheral surface of the sliding cylinder 13, protruding radially inward and extending continuously over the entire circumferential length.

[0022] An accommodating recess 16 for accommodating a lubricant such as grease is formed on at least one of the outer circumferential surface of the sliding cylinder 13 and the inner circumferential surface of the outer cylinder 12. In the illustrated example, the accommodating recess 16 is formed on the outer circumferential surface of the sliding cylinder 13. The accommodating recess 16 is composed of a plurality of grooves formed in stripes, and is formed over the entire length of the outer circumferential surface of the sliding cylinder 13 in both the axial and circumferential directions, and has a lattice shape when viewed from the outside in the radial direction. It is not necessary to provide the receiving recess 16 on the outer peripheral surface of the sliding cylinder 13 and the inner peripheral surface of the outer cylinder 12 .

[0023] Both axial ends of the inner cylinder 11 are located axially outward of both axial ends of the outer cylinder 12 . A bulging portion 17 that bulges outward in the radial direction is formed on the outer peripheral surface of the inner tube 11 in a portion surrounded from the radial outside by the sliding tube 13. The bulging portion 17 is formed in the central portion in the axial direction on the outer peripheral surface of the inner tube 11. The bulging portion 17 has a trapezoidal shape in a vertical cross-sectional view along one of the axial direction and the radial direction. The bulging portion 17 may be formed, for example, in a spherical shape, etc. Also, the bulging portion 17 may be formed on the outer circumferential surface of the inner cylinder 11 at a portion away from the axial center.

[0024] Steps 11a facing outward in the axial direction are formed on the outer circumferential surface of the inner cylinder 11 at both sides of the bulge 17 in the axial direction. The steps 11a are located axially inward of the step 12a of the outer cylinder 12. The steps 11a and the bulge 17 extend continuously over the entire circumferential length.

[0025] The first elastic body 14 connects the outer peripheral surface of the bulging portion 17 and the inner peripheral surface of the sliding tube 13. The first elastic body 14 connects the inner tube 11 and the outer tube 12 via the sliding tube 13. The first elastic body 14 is formed in a cylindrical shape from a rubber material or the like. The first elastic body 14 is arranged coaxially with the central axis O. The inner peripheral surface of the first elastic body 14 is bonded to the outer peripheral surface of the bulging portion 17. The outer peripheral surface of the first elastic body 14 is in pressure contact with the inner peripheral surface of the sliding tube 13. The first elastic body 14 is compressed and deformed in the radial direction. The first elastic body 14 is sandwiched in the axial direction by the restricting portions 13a formed separately at both ends in the axial direction on the inner peripheral surface of the sliding tube 13.

[0026] A plurality of ribs 14a, which protrude radially outward and extend continuously over the entire circumferential length, are formed at intervals in the axial direction on the outer circumferential surface of the first elastic body 14. The ribs 14a are crushed in the radial direction when the first elastic body 14 is fitted into the sliding tube 13. It is not necessary to form the rib 14a on the outer circumferential surface of the first elastic body 14.

[0027] The second elastic body 15 connects each portion located on both sides of the bulging portion 17 in the axial direction on the outer peripheral surface of the inner tube 11 to the inner peripheral surface of the outer tube 12 over the entire circumferential length. The pair of second elastic bodies 15 are formed into a cylindrical shape from a rubber material or the like, and extend continuously over the entire circumferential length. The second elastic body 15 is disposed coaxially with the central axis O. The second elastic body 15 is spaced outward in the axial direction from the sliding tube 13, the bulging portion 17, and the first elastic body 14. The second elastic body 15 may abut against the first elastic body 14 in the axial direction.

[0028] Here, the outer locking member 18 protrudes radially inward from the inner peripheral surface of the outer tube 12. The inner locking member 19 is provided axially inward from the outer locking member 18, and protrudes radially outward from the outer peripheral surface of the inner tube 11. The second elastic body 15 extends from the inside to the outside in the radial direction and then extends axially outward, and axially connects the inner locking member 19 and the outer locking member 18. The second elastic body 15 is provided in a state in which a compressive force is applied to it in the axial direction from the inner locking member 19 and the outer locking member 18.

[0029] In the illustrated example, the outer locking member 18 and the inner locking member 19 face each other in the axial direction. The outer locking member 18 and the inner locking member 19 are formed in an annular shape and disposed coaxially with the central axis O. The outer locking member 18 and the inner locking member 19 are formed in a plate shape with the front and back surfaces facing the axial direction. The outer locking member 18 and the inner locking member 19 extend from the inner side to the outer side in the radial direction and then toward the inner side in the axial direction.

[0030] The outer locking member 18 and the inner locking member 19 may extend straight in the radial direction. The outer locking member 18 may be formed integrally with the outer tube 12, and the inner locking member 19 may be formed integrally with the inner tube 11. The outer locking member 18 and the inner locking member 19 may be separated from each other in the radial direction and may not face each other in the axial direction.

[0031] The radial inner end of the outer locking member 18 is separated from the outer peripheral surface of the inner tube 11 toward the outside in the radial direction. The radial outer end of the outer locking member 18 extends straight in the radial direction. The crimped portion 12b of the outer tube 12 abuts against the outer surface of the radial outer end of the outer locking member 18 facing outward in the axial direction. The elastically deformable first seal portion 21 is provided on the inner surface of the radial outer end of the outer locking member 18 facing inward in the axial direction. The first seal portion 21 is formed of a rubber material or the like, and is formed integrally with the second elastic body 15. The first seal portion 21 extends continuously over the entire length in the circumferential direction. The first seal portion 21 is in axial pressure contact with the step portion 12a formed on the inner peripheral surface of the outer tube 12. The radial outer end of the outer locking member 18 is fixed by being sandwiched in the axial direction between the step portion 12a and the crimped portion 12b of the outer tube 12.

[0032] The radial outer end of the inner locking member 19 is radially inward from the inner peripheral surface of the outer tube 12, and axially outward from the sliding tube 13, the bulge 17, and the first elastic body 14. The radial inner end of the inner locking member 19 extends straight in the radial direction. An elastically deformable second seal portion 22 is provided on the inner surface of the radial inner end of the inner locking member 19 facing inward in the axial direction. The second seal portion 22 is made of a rubber material or the like, and is formed integrally with the second elastic body 15. The second seal portion 22 extends continuously over the entire circumferential length. The second seal portion 22 is axially pressed against a step portion 11a formed on the outer peripheral surface of the inner tube 11. A fitting tube 19a is formed at the radially inner end of the inner locking member 19, which extends axially outward and into which the axial end of the inner tube 11 is fitted to fix the inner locking member 19 to the inner tube 11.

[0033] As described above, according to the vibration-proof bushing 1 of this embodiment, the outer peripheral surface of the inner cylinder 11 and the inner peripheral surface of the outer cylinder 12 are connected to the first elastic body 14 and the second elastic body 15, so that when the inner cylinder 11 and the outer cylinder 12 are relatively displaced so that their central axes cross each other, and vibration in the prying direction is input, the first elastic body 14 and the second elastic body 15 are elastically deformed. At this time, the pair of second elastic bodies 15 that sandwich the bulge 17 in the axial direction extend axially outward as they move from the inside to the outside in the radial direction, and connect the inner locking member 19 and the outer locking member 18 in the axial direction, so that the second elastic body 15 can be shear-deformed in response to a load in the prying direction, and a low spring can be achieved against input vibration in the prying direction.

[0034] Since a first elastic body 14 is provided connecting the outer peripheral surface of the bulge portion 17 and the inner peripheral surface of the sliding tube 13, when radial vibration is input, the first elastic body 14 and the second elastic body 15 elastically deform, causing the outer tube 12 and the inner tube 11 to elastically displace relative to each other in the radial direction, making it easy to adjust the spring against the input radial vibration. Since the second elastic body 15 is located axially outwardly away from the sliding tube 13 and the bulge portion 17, when axial vibrations and vibrations around the central axis O are input, the second elastic body 15 elastically deforms smoothly in accordance with the relative displacement of the inner tube 11 and the outer tube 12, while the sliding tube 13 slides along the inner surface of the outer tube 12.

[0035] Since the second elastic body 15 is provided in a state in which a compressive force is applied in the axial direction from the inner locking member 19 and the outer locking member 18, it is possible to prevent the relative axial positions of the outer tube 12, and the inner tube 11 and the sliding tube 13 from shifting before and after the load input, and it is also possible to ensure the durability of the second elastic body 15.

[0036] Since the outer locking member 18 and the inner locking member 19 extend axially inwardly as they move from the radially inner side to the radially outer side, the second elastic body 15 can be reliably shear-deformed by a load in the prying direction.

[0037] Since a storage recess 16 for storing a lubricant is formed on at least one of the outer peripheral surface of the sliding cylinder 13 and the inner peripheral surface of the outer cylinder 12, it becomes possible to retain the lubricant between the outer peripheral surface of the sliding cylinder 13 and the inner peripheral surface of the outer cylinder 12, and the smooth sliding of the sliding cylinder 13 can be maintained for a long period of time.

[0038] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0039] For example, it is not necessary to provide the first seal portion 21 on the outer locking member 18 and the second seal portion 22 on the inner locking member 19, respectively. The inner locking member 19 does not need to be formed with the fitting cylinder 19a. A recess may be provided on the outer circumferential surface of the first elastic body 14, for example, in a portion facing a direction in which transmission of vibration is desired to be reduced.

[0040] In addition, within the scope of the spirit of the present invention, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, and the above-described embodiments and variations may be combined as appropriate. [Explanation of symbols]

[0041] 1 Anti-vibration bush 11 Inner cylinder 12 Outer cylinder 13 Sliding tube 14 First Elastic Body 15 Second Elastic Body 16 Recessed portion 17 Bulge 18 Outer locking member 19 Inner locking member O center axis

Claims

1. an inner cylinder connected to one of the vibration generating unit and the vibration receiving unit, and an outer cylinder connected to the other and surrounding the inner cylinder from the outside in the radial direction; A sliding cylinder slidably fitted in the outer cylinder, A bulging portion that bulges outward in the radial direction is formed on the outer circumferential surface of the inner cylinder in a portion surrounded by the sliding cylinder from the radial outside, a first elastic body connecting an outer peripheral surface of the bulging portion and an inner peripheral surface of the sliding cylinder; a pair of second elastic bodies that connect the inner peripheral surface of the outer tube and each of the portions located on both sides of the bulge in the axial direction along the central axis of the inner tube, over the entire circumferential length thereof; an outer engaging member protruding radially inward from an inner peripheral surface of the outer cylinder; an inner locking member provided on the inner side of the outer locking member on the bulging portion side along the axial direction and protruding radially outward from an outer peripheral surface of the inner cylinder, The second elastic body extends outward in the axial direction, away from the bulge portion, as it moves from the radially inner side to the radially outer side, connects the inner engaging member and the outer engaging member in the axial direction, and is spaced outward in the axial direction from the sliding tube and the bulge portion.

2. 2. The vibration-isolating bushing according to claim 1, wherein the second elastic body is provided in a state in which a compressive force is applied in the axial direction from the inner engaging member and the outer engaging member.

3. 3. The vibration-isolating bushing according to claim 1, wherein the outer engaging member and the inner engaging member extend radially from the inner side to the outer side and then axially inward.

4. 4. The vibration-isolating bushing according to claim 1, wherein a receiving recess for receiving a lubricant is formed in at least one of an outer circumferential surface of the sliding cylinder and an inner circumferential surface of the outer cylinder.

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