JP7619907B2 - Anti-Vibration Bushings - Google Patents

Description

The present invention relates to vibration-proof bushings.

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.

Japanese Patent Application Publication No. 6-129460

However, the conventional vibration-proof bushings had the problem that it was difficult to achieve low spring resistance against input vibration in the twisting direction.

This invention was made in consideration of these circumstances, and aims to provide a vibration-proof bushing that can reduce spring resistance against input vibration in the twisting direction.

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 one of 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, and a bulge portion bulging outward in the radial direction is formed on the outer peripheral surface of the inner tube in the 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 two elastic bodies located on both sides of the outer peripheral surface of the inner tube, sandwiching the bulge portion in the axial direction along the central axis of the inner tube. The second elastic body includes a pair of second elastic bodies that connect each of the portions of the outer tube and the inner peripheral surface of the outer tube over the entire circumferential length, an outer locking member that protrudes radially inward from the inner peripheral surface of the outer tube, and an inner locking member that is provided on the inside of the outer locking member, closer to the bulging portion along the axial direction, and protrudes radially outward from the outer peripheral surface of the inner tube. The second elastic body extends outward in the axial direction, away from the bulging portion as it moves from the radial inside to the outside, and 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 bulging portion.

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 relatively 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 response to the relative displacement of the inner tube and the outer tube, while the sliding tube slides along the inner surface of the outer tube.

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.

The second elastic body is provided with a compressive force applied in the axial direction, which prevents the relative axial positions of the outer tube, inner tube, and sliding tube from shifting before and after the load input, and ensures the durability of the second elastic body.

The outer locking member and the inner locking member may extend from the inside to the outside in the radial direction and then extend toward the inside in the axial direction.

The outer and inner locking members extend from the inside to the outside in the radial direction and then toward the inside in the axial direction, so that the second elastic body can be reliably sheared against a prying load.

A recess for containing a lubricant may be formed on at least one of the outer peripheral surface of the sliding cylinder and the inner peripheral surface of the outer cylinder.

A recess for containing 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, making it 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.

This invention makes it possible to reduce spring resistance against input vibration in the twisting direction.

FIG. 2 is a vertical cross-sectional view of a vibration-isolating bushing shown as an embodiment. 2 is a cross-sectional view taken along line II-II of FIG. 1.

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.

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 bushing 1 is used, for example, as a suspension bushing 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.

Hereinafter, the direction along the central axis O of the inner cylinder 11 is 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 is referred to as the radial direction, and the direction going around the central axis O is referred to as the circumferential direction.

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 straight line L passing through the axial center portion in a vertical cross-sectional view along one of the axial direction and the radial direction.
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.

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

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

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 accommodating recess 16 on the outer peripheral surface of the sliding cylinder 13 and the inner peripheral surface of the outer cylinder 12 .

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.

On the outer circumferential surface of the inner tube 11, steps 11a facing outward in the axial direction are formed in each portion located on both sides of the bulge 17 in the axial direction. The steps 11a are located axially inward from the steps 12a of the outer tube 12. The steps 11a and the bulge 17 extend continuously over the entire circumferential length.

The first elastic body 14 connects the outer peripheral surface of the bulge 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 bulge 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 axial ends of the inner peripheral surface of the sliding tube 13.

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 14 a on the outer circumferential surface of the first elastic body 14 .

The second elastic body 15 connects the portions located on both sides of the bulge 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 bulge 17, and the first elastic body 14. The second elastic body 15 may abut against the first elastic body 14 in the axial direction.

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 of 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 the second elastic body 15 from the inner locking member 19 and the outer locking member 18 in the axial direction.

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 are arranged 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 inside to the outside in the radial direction and then toward the inside in the axial direction.

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.

The radial inner end of the outer locking member 18 is spaced radially outward from the outer peripheral surface of the inner tube 11. 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 made 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 circumferential length. The first seal portion 21 is axially pressed against the step portion 12a formed on the inner peripheral surface of the outer tube 12. The radially outer end of the outer locking member 18 is clamped and fixed in the axial direction between the step portion 12a and the crimped portion 12b of the outer tube 12.

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 the step portion 11a formed on the outer peripheral surface of the inner tube 11. The inner radial end of the inner locking member 19 is formed with a fitting tube 19a that extends axially outward and fits into the axial end of the inner tube 11, fixing the inner locking member 19 to the inner tube 11.

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

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 spaced axially outward 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.

The second elastic body 15 is provided with a compressive force applied in the axial direction from the inner locking member 19 and the outer locking member 18, which prevents the relative axial positions of the outer tube 12, the inner tube 11, and the sliding tube 13 from shifting before and after the load input, and ensures the durability of the second elastic body 15.

The outer locking member 18 and the inner locking member 19 extend radially from the inside to the outside and then axially inward, so that the second elastic body 15 can be reliably sheared against a prying load.

A storage recess 16 for storing a lubricant is formed on at least one of the outer peripheral surface of the sliding tube 13 and the inner peripheral surface of the outer tube 12, making it possible to retain the lubricant between the outer peripheral surface of the sliding tube 13 and the inner peripheral surface of the outer tube 12, thereby maintaining smooth sliding of the sliding tube 13 for a long period of time.

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.

For example, it is not necessary to provide the first seal portion 21 on the outer engaging member 18 and the second seal portion 22 on the inner engaging member 19 .
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.

In addition, the components in the above-described embodiments may be replaced with well-known components as appropriate without departing from the spirit of the present invention, and the above-described embodiments and variations may be combined as appropriate.

REFERENCE SIGNS LIST 1 anti-vibration bushing 11 inner cylinder 12 outer cylinder 13 sliding cylinder 14 first elastic body 15 second elastic body 16 accommodation recess 17 bulge 18 outer locking member 19 inner locking member O central axis

Claims (4)

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 radial inside to the radial outside, 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. The vibration-proof bushing of 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. An anti-vibration bushing according to claim 1 or 2, in which the outer engaging member and the inner engaging member extend from the inner side to the outer side in the radial direction and then extend toward the inner side in the axial direction. An anti-vibration bushing according to any one of claims 1 to 3, in which a receiving recess for receiving 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.

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