JP2022038658A - Vibration control bush - Google Patents

Abstract

To reduce axial rigidity without softening an elastic body.SOLUTION: A vibration control bush includes: an outer cylinder 11; an inner cylinder 12 attached to one of a vibration generating part F and a vibration receiving part R and disposed at the inner side of the outer cylinder; an elastic body 14 which connects the outer cylinder with the inner cylinder; a case cylinder 21 which is attached to the other of the vibration generating part and the vibration receiving part and in which the outer cylinder is disposed so as to be movable relative to the case cylinder 21 in an axial direction along a center axis O of the vibration control bush 1; and an air chamber 22 whose volumetric capacity expands or contracts in conjunction with the outer cylinder and the case cylinder moving relative to each other in the axial direction.SELECTED DRAWING: Figure 2

Description

The present invention relates to an anti-vibration bush.

Conventionally, for example, as shown in Patent Document 1 below, an outer cylinder attached to either one of a vibration generating portion and a vibration receiving portion, and an inner cylinder attached to the other and arranged inside the outer cylinder. A vibration-proof bush having a cylinder and an elastic body connecting an outer cylinder and an inner cylinder is known.

Japanese Unexamined Patent Publication No. 2004-221791

However, in the conventional anti-vibration bush, for example, if the elastic body is softened to reduce the axial rigidity along the central axis of the anti-vibration bush in order to reduce road noise, the durability is lowered. There is a risk that the steering stability may deteriorate during turning.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a vibration-proof bush that can reduce the rigidity in the axial direction without softening the elastic body.

In order to solve the above problems, the present invention proposes the following means.
The vibration-proof bush according to the present invention is attached to one of an outer cylinder, a vibration generating portion and a vibration receiving portion, and is an inner cylinder disposed inside the outer cylinder, and the outer cylinder and the said. The outer cylinder is attached to the elastic body connected to the inner cylinder and one of the vibration generating portion and the vibration receiving portion, and the outer cylinder moves inward in the axial direction along the central axis of the vibration isolator bush. It includes a case cylinder that is possibly arranged, and an air chamber whose volume expands and contracts as the outer cylinder and the case cylinder move relative to each other in the axial direction.

According to the present invention, the volume of the air chamber expands and contracts as the outer cylinder and the case cylinder move relative to each other in the axial direction. Therefore, when the vibration in the axial direction is input, the volume of the air chamber expands and contracts to provide air. The outer cylinder and the case cylinder can be relatively moved in the axial direction while increasing or decreasing the internal pressure of the chamber, and the outer cylinder and the case cylinder are supported by the air chamber so as to be elastically displaceable in the axial direction. The Rukoto. As a result, the axial rigidity of the anti-vibration bush depends not on the rigidity of the elastic body but on the volume of the air chamber, and the axial rigidity of the anti-vibration bush can be increased without softening the elastic body. It can be kept low.
Since the outer cylinder and the case cylinder are supported by the internal pressure of the air chamber so as to be elastically displaceable in the axial direction, the rigidity of the vibration-proof bush in the axial direction depends on the rigidity of the elastic body. In comparison, it can be easily and greatly reduced. As a result, the axial resonance frequency of the anti-vibration bush can be largely separated from the unsprung resonance frequency in the axial direction to a lower side, floor vibration is suppressed, and riding comfort is improved. You can make it happen.

The outer cylinder is provided with a sliding cylinder sandwiched in the radial direction by the outer peripheral surface of the outer cylinder and the inner peripheral surface of the case cylinder, the outer cylinder and the case cylinder are formed of a metal material, and the sliding cylinder is made of resin. It may be formed of a material.

In this case, the outer cylinder and the case cylinder are formed of a metal material, and the sliding cylinder sandwiched in the radial direction by the outer peripheral surface of the outer cylinder and the inner peripheral surface of the case cylinder is formed of a resin material. When assembling the anti-vibration bush, the sliding cylinder is easily deformed, and the anti-vibration bush can be easily assembled without increasing the dimensional accuracy of the outer cylinder, the case cylinder, and the sliding cylinder.

A sliding cylinder is provided which is sandwiched in the radial direction by the outer peripheral surface of the outer cylinder and the inner peripheral surface of the case cylinder, and one of the outer peripheral surface and the inner peripheral surface of the sliding cylinder is the outer cylinder. Is fixed to either the outer peripheral surface of the outer cylinder or the inner peripheral surface of the case cylinder, and any one of the outer peripheral surface and the inner peripheral surface of the sliding cylinder is the outer peripheral surface of the outer cylinder and the case cylinder. Is provided slidably on any one of the inner peripheral surfaces of the above in the axial direction, and any one of the outer peripheral surface and the inner peripheral surface of the sliding cylinder, the outer peripheral surface of the outer cylinder, and the said. The coefficient of dynamic friction between any one of the inner peripheral surfaces of the case cylinder and the other may be smaller than the coefficient of dynamic friction between the outer peripheral surface of the outer cylinder and the inner peripheral surface of the case cylinder.

In this case, a sliding cylinder is provided which is sandwiched in the radial direction by the outer peripheral surface of the outer cylinder and the inner peripheral surface of the case cylinder, and the outer cylinder is provided with any one of the outer peripheral surface and the inner peripheral surface of the sliding cylinder, and the outer cylinder. Since the coefficient of dynamic friction between the outer peripheral surface and the inner peripheral surface of the case cylinder is smaller than the coefficient of dynamic friction between the outer peripheral surface of the outer cylinder and the inner peripheral surface of the case cylinder. , The outer cylinder and the case cylinder can be smoothly moved relative to the axial direction when the vibration in the axial direction is input.

The outer cylinder is provided with an inner peripheral wall protruding toward one side in the axial direction, and the case cylinder is provided with an inner peripheral wall protruding toward one side in the axial direction, and is radially on the outer peripheral surface of the inner peripheral wall. An outer peripheral wall facing from the outside is provided, and the outer cylinder or the inner peripheral wall protrudes outward in the radial direction and abuts slidably on the inner peripheral surface of the outer peripheral wall in the axial direction. A second end wall provided with one end wall portion, projecting inward in the radial direction from the case cylinder or the outer peripheral wall, and slidably contacting the outer peripheral surface of the inner peripheral wall in the axial direction. A portion is provided, and the air chamber is defined by being surrounded by an outer peripheral surface of the inner peripheral wall, an inner peripheral surface of the outer peripheral wall, the first end wall portion, and the second end wall portion. May be.

In this case, since the air chamber is located so as to project from the outer cylinder and the case cylinder to one side in the axial direction, it is easy to secure a wide volume of the air chamber with less restrictions, and the rigidity of the vibration isolator bush in the axial direction. Can be easily lowered.

According to the present invention, it is possible to reduce the rigidity in the axial direction along the central axis of the vibration-proof bush without softening the elastic body.

It is sectional drawing in the central part in the axial direction of the anti-vibration bush which concerns on 1st Embodiment of this invention. FIG. 1 is a cross-sectional view taken along the line II-II of the anti-vibration bush of FIG. It is sectional drawing in the central part in the axial direction of the anti-vibration bush which concerns on 2nd Embodiment of this invention. FIG. 3 is a cross-sectional view taken along the line IV-IV of the anti-vibration bush of FIG. It is a modification of the vibration-proof bush of FIG.

Hereinafter, the anti-vibration bush according to the first embodiment of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the vibration-proof bush 1 is attached to either the outer cylinder 11 or the vibration generating portion F or the vibration receiving portion R, and is arranged inside the outer cylinder 11. The inner cylinder 12 is provided with an elastic body 14 connecting the outer cylinder 11 and the inner cylinder 12.
In the illustrated example, the intermediate cylinder 13 is fitted in the outer cylinder 11. The elastic body 14 adheres the outer peripheral surface of the inner cylinder 12 and the inner peripheral surface of the intermediate cylinder 13, and connects the outer cylinder 11 and the inner cylinder 12 via the intermediate cylinder 13. The intermediate cylinder 13 may not be provided.

The outer cylinder 11, the inner cylinder 12, and the intermediate cylinder 13 are arranged coaxially with the common axis (central axis) O. Hereinafter, the direction along the common axis O is referred to as an axial direction, the direction intersecting the common axis O when viewed from the axial direction is referred to as a radial direction, and the direction orbiting around the common axis O is referred to as a circumferential direction. In the axial direction, the central side of the anti-vibration bush 1 is referred to as the inside, and the side away from the central portion of the anti-vibration bush 1 is referred to as the outside.

The central portions of the outer cylinder 11, the inner cylinder 12, the intermediate cylinder 13, and the elastic body 14 in the axial direction coincide with each other. The axial outer end opening edge of the inner cylinder 12 is located outside the axial direction of the outer end opening edge of the outer cylinder 11 and the intermediate cylinder 13, respectively.
The central portion of each of the outer cylinder 11, the inner cylinder 12, the intermediate cylinder 13, and the elastic body 14 in the axial direction may be displaced in the axial direction. Further, for example, the outer end opening edge in the axial direction of each of the outer cylinder 11, the inner cylinder 12, and the intermediate cylinder 13 may be positioned at the same position in the axial direction.

The outer peripheral surface of the inner cylinder 12 has a rectangular shape having a pair of first side portions 12a and a pair of second side portions 12b when viewed from the axial direction. The first side portion 12a extends in one of the radial directions when viewed from the axial direction, and the second side portion 12b extends in one of the radial directions orthogonal to the one direction when viewed from the axial direction. It is extending. A bulging portion 12c protruding in one direction is formed at the central portion in the axial direction of the second side portion 12b. The bulging portion 12c exhibits a curved shape of a protrusion toward the outside in the radial direction when viewed from the axial direction, and exhibits a linear shape extending in the axial direction in a vertical cross-sectional view along the axial direction. The bulging portion 12c is formed over the entire area of the second side portion 12b in the other direction.

The elastic body 14 is made of a rubber material. Of the elastic body 14, the main body portion 14a connected to the first side portion 12a of the inner cylinder 12 is connected to the inner peripheral surface of the intermediate cylinder 13. Of the elastic body 14, the stopper portion 14b adjacent to the main body portion 14a in the circumferential direction and connected to the second side portion 12b of the inner cylinder 12 is radially inward from the inner peripheral surface of the intermediate cylinder 13. .. The stopper portion 14b is connected to the bulging portion 12c of the second side portion 12b. The stopper portion 14b is provided so as to be in contact with the inner peripheral surface of the intermediate cylinder 13.

In the present embodiment, the case cylinder 21 is attached to either one of the vibration generating portion F and the vibration receiving portion R, and the outer cylinder 11 is arranged inside so as to be relatively movable in the axial direction. It includes an air chamber 22 whose volume expands and contracts as the outer cylinder 11 and the case cylinder 21 move relative to each other in the axial direction.
Examples of the vibration generating portion F include a suspension frame and a body frame, and examples of the vibration receiving portion R include, for example, a body and a cabin provided above the vibration generating portion F.

The anti-vibration bush 1 is provided in a suspension device having a vibration generating portion F, and supports a vibration receiving portion R provided above the vibration generating portion F.
In the illustrated example, the case cylinder 21 is attached to the vibration generating portion F, and the inner cylinder 12 is attached to the vibration receiving portion R.

A plurality of anti-vibration bushes 1 are provided on both sides of the vehicle, sandwiching the central portion in the left-right direction in the left-right direction, at intervals in the front-rear direction. The anti-vibration bush 1 is provided at each position of the vehicle on both sides sandwiching the central portion in the left-right direction of the vehicle in the left-right direction at the same position in the front-rear direction of the vehicle and facing each other in the left-right direction of the vehicle.
For example, when the vibration generating portion F is a suspension frame, the anti-vibration bush 1 is located on both sides of the vehicle in the left-right direction, and the front wheels or the rear wheels are located on both sides of the vehicle in the front-rear direction. One is provided for each part.

The anti-vibration bush 1 has an axial direction oriented in the vertical direction, one of the radial directions directed to the front-rear direction of the vehicle, and the other radial direction directed to the left-right direction of the vehicle. In this state, it is attached to the vibration generating portion F and the vibration receiving portion R for use.
In the illustrated example, in the vibration-proof bush 1, the main body portion 14a of the elastic body 14 and the first side portion 12a of the inner cylinder 12 are arranged in the left-right direction of the vehicle, and the stopper portion 14b of the elastic body 14 and the inner cylinder 12 are arranged. The second side portion 12b of the above is attached to the vibration generating portion F and the vibration receiving portion R in a posture of arranging in the front-rear direction of the vehicle.
In this case, since the main body 14a of the elastic body 14 connected to both the outer peripheral surface of the inner cylinder 12 and the inner peripheral surface of the intermediate cylinder 13 are arranged in the left-right direction of the vehicle, the vehicle of the vibration-proof bush 1 It is possible to increase the rigidity in the left-right direction, and it is possible to improve the steering stability when the vehicle is turning.

A sliding cylinder 23 is provided which is sandwiched in the radial direction by the outer peripheral surface of the outer cylinder 11 and the inner peripheral surface of the case cylinder 21. The outer cylinder 11 and the case cylinder 21 are made of a metal material, and the sliding cylinder 23 is made of a resin material. Examples of this resin material include low friction materials such as polyacetal.

One of the outer peripheral surface and the inner peripheral surface of the sliding cylinder 23 is fixed to either the outer peripheral surface of the outer cylinder 11 or the inner peripheral surface of the case cylinder 21, and the outer peripheral surface of the sliding cylinder 23 is fixed. And any one of the inner peripheral surfaces is provided so as to be slidable in the axial direction on any one of the outer peripheral surface of the outer cylinder 11 and the inner peripheral surface of the case cylinder 21. The coefficient of dynamic friction between the outer peripheral surface and the inner peripheral surface of the sliding cylinder 23 and any other of the outer peripheral surface of the outer cylinder 11 and the inner peripheral surface of the case cylinder 21 is determined. It is smaller than the coefficient of dynamic friction between the outer peripheral surface of the outer cylinder 11 and the inner peripheral surface of the case cylinder 21.

Any one of the outer peripheral surface and the inner peripheral surface of the sliding cylinder 23 is provided slidably in the circumferential direction on any one of the outer peripheral surface of the outer cylinder 11 and the inner peripheral surface of the case cylinder 21. ing.
Between one of the outer peripheral surface and the inner peripheral surface of the sliding cylinder 23 and any other of the outer peripheral surface of the outer cylinder 11 and the inner peripheral surface of the case cylinder 21, for example, grease or the like. The lubricant may be provided.

In the illustrated example, the outer peripheral surface of the sliding cylinder 23 is fixed to the inner peripheral surface of the case cylinder 21, and the inner peripheral surface of the sliding cylinder 23 is provided on the outer peripheral surface of the outer cylinder 11 so as to be slidable in the axial direction. Has been done. The coefficient of dynamic friction between the inner peripheral surface of the sliding cylinder 23 and the outer peripheral surface of the outer cylinder 11 is based on the coefficient of dynamic friction between the outer peripheral surface of the outer cylinder 11 and the inner peripheral surface of the case cylinder 21. It's getting smaller.
Screws or the like are driven into the case cylinder 21 and the sliding cylinder 23 from the radial outside of the case cylinder 21 to fix the case cylinder 21 and the sliding cylinder 23 to each other, whereby the outer periphery of the sliding cylinder 23 is fixed. The surface is fixed to the inner peripheral surface of the case cylinder 21.

The air chamber 22 is defined by being surrounded by an outer peripheral surface of the inner peripheral wall 25, an inner peripheral surface of the outer peripheral wall 26, a first end wall portion 27, and a second end wall portion 28. The air chamber 22 is an annular space coaxially arranged with the common axis O.

The inner peripheral wall 25 is provided on the outer cylinder 11 and projects from the outer cylinder 11 toward one side in the axial direction.
Hereinafter, one side in the axial direction is referred to as a lower side, and the other side in the axial direction is referred to as an upper side.
A first flange portion 11a is formed at the lower end portion of the outer cylinder 11 so as to project inward in the radial direction and continuously extend over the entire length in the circumferential direction. The inner peripheral wall 25 extends downward from the inner peripheral edge portion of the first flange portion 11a. The inner peripheral wall 25 is located inside the outer cylinder 11 in the radial direction. The inner peripheral surface of the inner peripheral wall 25 is separated radially outward from the outer peripheral surface of the inner cylinder 12. The inner peripheral surface of the upper end portion of the inner peripheral wall 25 faces the outer peripheral surface of the inner cylinder 12 in the radial direction. The lower end of the inner peripheral wall 25 is located below the lower end opening edge of the inner cylinder 12.

The outer peripheral wall 26 is provided on the case cylinder 21 and projects downward from the case cylinder 21. The outer peripheral wall 26 surrounds the inner peripheral wall 25 from the outside in the radial direction, and the inner peripheral surface of the outer peripheral wall 26 faces the outer peripheral surface of the inner peripheral wall 25 in the radial direction. A second flange portion 21a is formed at the lower end portion of the case cylinder 21 so as to project outward in the radial direction and continuously extend over the entire length in the circumferential direction. The outer peripheral wall 26 extends downward from the outer peripheral edge portion of the second flange portion 21a. The outer peripheral wall 26 is located on the outer side in the radial direction from the case cylinder 21.

The first end wall portion 27 is provided on the outer cylinder 11 or the inner peripheral wall 25. In the illustrated example, the first end wall portion 27 is provided on the inner peripheral wall 25 and projects outward from the inner peripheral wall 25 in the radial direction. The first end wall portion 27 is provided at the lower end portion of the inner peripheral wall 25. The first end wall portion 27 extends continuously over the entire length in the circumferential direction. The outer peripheral surface of the first end wall portion 27 is in axially slidable contact with the inner peripheral surface of the outer peripheral wall 26. An O-ring is provided on the outer peripheral surface of the first end wall portion 27 so as to be slidably and closely contacted with the inner peripheral surface of the outer peripheral wall 26 in the axial direction.

The second end wall portion 28 is provided on the case cylinder 21 or the outer peripheral wall 26. In the illustrated example, the second end wall portion 28 is provided on the outer peripheral wall 26 and protrudes inward in the radial direction from the outer peripheral wall 26. The second end wall portion 28 is provided at the upper end portion of the outer peripheral wall 26 and is integrally formed with the second flange portion 21a. The second end wall portion 28 extends continuously over the entire length in the circumferential direction. The inner peripheral surface of the second end wall portion 28 is in axially slidable contact with the outer peripheral surface of the inner peripheral wall 25. An O-ring is provided on the inner peripheral surface of the second end wall portion 28 so as to be slidably and closely contacted with the outer peripheral surface of the inner peripheral wall 25 in the axial direction.

The second end wall portion 28 is located above the first end wall portion 27. The lower surface of the second end wall portion 28 faces the upper surface of the first end wall portion 27 in the axial direction, and the lower surface of the second end wall portion 28 and the upper surface of the first end wall portion 27 are air chambers 22. Is defined. The air chamber 22 is located so as to project downward from the outer cylinder 11 and the case cylinder 21.
In the above configuration, when the anti-vibration bush 1 is attached to the vibration generating portion F and the vibration receiving portion R and a static load downward is applied to the case cylinder 21, the case cylinder 21, the sliding cylinder 23, and the outer peripheral wall 26 are applied. , And the second end wall portion 28 descends with respect to the outer cylinder 11, the inner peripheral wall 25, and the first end wall portion 27, and the volume of the air chamber 22 is reduced.

As described above, according to the vibration-proof bush 1 according to the present embodiment, the volume of the air chamber 22 expands and contracts as the outer cylinder 11 and the case cylinder 21 move relative to each other in the axial direction, so that vibration in the axial direction occurs. At the time of inputting, the volume of the air chamber 22 is expanded or contracted to increase or decrease the internal pressure of the air chamber 22, and the outer cylinder 11 and the case cylinder 21 can be relatively moved in the axial direction, so that the outer cylinder 11 and the case cylinder 21 can be moved relative to each other. However, it is supported by the air chamber 22 so as to be relatively elastically displaceable in the axial direction.
As a result, the axial rigidity of the anti-vibration bush 1 depends not on the rigidity of the elastic body 14 but on the volume of the air chamber 22, and the axial rigidity of the anti-vibration bush 1 does not need to be softened. Rigidity can be kept low.

Since the outer cylinder 11 and the case cylinder 21 are supported by the internal pressure of the air chamber 22 so as to be elastically displaceable in the axial direction, the axial rigidity of the vibration isolator bush 1 depends on the rigidity of the elastic body 14. It can be easily and greatly reduced as compared with the case of doing so. As a result, the axial resonance frequency of the anti-vibration bush 1 can be largely separated from the unsprung resonance frequency in the axial direction to the lower side, floor vibration is suppressed, and riding comfort is improved. You can do things.

The outer cylinder 11 and the case cylinder 21 are formed of a metal material, and the sliding cylinder 23 sandwiched in the radial direction by the outer peripheral surface of the outer cylinder 11 and the inner peripheral surface of the case cylinder 21 is formed of a resin material. Therefore, when assembling the anti-vibration bush 1, the sliding cylinder 23 is easily deformed, and the anti-vibration bush 1 can be easily made without increasing the dimensional accuracy of the outer cylinder 11, the case cylinder 21, and the sliding cylinder 23. Can be assembled into.

A sliding cylinder 23 is provided which is sandwiched in the radial direction by the outer peripheral surface of the outer cylinder 11 and the inner peripheral surface of the case cylinder 21, and is provided with any one of the outer peripheral surface and the inner peripheral surface of the sliding cylinder 23 and the outer cylinder. The coefficient of dynamic friction between the outer peripheral surface of 11 and any one of the inner peripheral surfaces of the case cylinder 21 is based on the dynamic friction coefficient between the outer peripheral surface of the outer cylinder 11 and the inner peripheral surface of the case cylinder 21. Since it is small, the outer cylinder 11 and the case cylinder 21 can be smoothly moved relative to each other in the axial direction when the vibration in the axial direction is input.

Since the air chamber 22 is located so as to project downward from the outer cylinder 11 and the case cylinder 21, it is easy to secure a wide volume of the air chamber 22 with few restrictions, and the axial rigidity of the vibration isolator bush 1 is easily lowered. can do.

Next, the second embodiment according to the present invention will be described, but the basic configuration is the same as that of the first embodiment. Therefore, the same reference numerals are given to the same configurations, the description thereof will be omitted, and only the different points will be described.

In the anti-vibration bush 2 according to the present embodiment, as shown in FIGS. 3 and 4, two liquid chambers 15 and an orifice passage 16 that communicates these liquid chambers 15 are arranged inside the outer cylinder 11. It is set up. At least a portion of the inner surface of each of the liquid chamber 15 and the orifice passage 16 is defined by a rubber material. The axial size of the liquid chamber 15 is larger than the axial size of the orifice passage 16, and the orifice passage 16 opens at the central portion of the liquid chamber 15 in the axial direction.
In the illustrated example, one orifice passage 16 is provided. For example, ethylene glycol, water, silicone oil, or the like is sealed in the liquid chamber 15 and the orifice passage 16. Two orifice passages 16 may be provided.

Two through holes 13a are formed in the intermediate cylinder 13 at intervals in the circumferential direction, and these through holes 13a face each other in one of the radial directions. The through hole 13a is formed in the entire portion of the intermediate cylinder 13 located inside in the axial direction from both ends in the axial direction. An orifice passage 16 is provided between the outer peripheral surface of the intermediate cylinder 13 located between the through holes 13a adjacent to each other in the circumferential direction and the inner peripheral surface of the outer cylinder 11.
Hereinafter, the portion of the intermediate cylinder 13 located between the through holes 13a adjacent to each other in the circumferential direction is referred to as an intermediate portion 13b of the intermediate cylinder 13.

A recess portion extending in the circumferential direction and opening to the through hole 13a is formed in the central portion in the axial direction on the outer peripheral surface of each intermediate portion 13b. The inside of each recess is filled with the covering rubber 14c. The coated rubber 14c is integrally formed with the elastic body 14. The orifice passage 16 is a groove portion extending in the circumferential direction formed on the outer peripheral surface of the coated rubber 14c.

The elastic body 14 is connected to the inner peripheral surface of the intermediate portion 13b and the opening peripheral edge portion 13c of the through hole 13a on the inner peripheral surface of the intermediate cylinder 13, so that the liquid chamber 15 is defined inside the through hole 13a. ing. The elastic body 14 is connected over the entire circumference of the opening peripheral edge portion 13c of the through hole 13a on the inner peripheral surface of the intermediate cylinder 13. Of the elastic body 14, at least a portion connected to the opening peripheral edge portion 13c of the through hole 13a on the inner peripheral surface of the intermediate cylinder 13 defines a part of the inner surface of the liquid chamber 15.
On the outer peripheral surface of the intermediate cylinder 13, O-rings that are in close contact with the inner peripheral surface of the outer cylinder 11 are provided at each position sandwiching the liquid chamber 15 from both sides in the axial direction.

The main body portion 14a of the elastic body 14 is connected to the inner peripheral surface of the intermediate portion 13b of the intermediate cylinder 13.
The stopper portion 14b of the elastic body 14 is located in the liquid chamber 15 and is provided so as to be able to come into contact with the inner peripheral surface of the outer cylinder 11 through the through hole 13a. The stopper portion 14b is arranged at the central portion in the axial direction in each of the inner cylinder 12 and the liquid chamber 15.

The anti-vibration bush 2 has an axial direction oriented in the vertical direction, one of the radial directions directed to the front-rear direction of the vehicle, and the other direction orthogonal to the one radial direction of the vehicle. It is used by being attached to the vibration generating portion F and the vibration receiving portion R in a state of being oriented in the left-right direction. That is, in the vibration-proof bush 2, the main body portion 14a of the elastic body 14 and the first side portion 12a of the inner cylinder 12 are arranged in the left-right direction of the vehicle, and the liquid chamber 15 and the stopper portion 14b of the elastic body 14 are the vehicle. It is attached to the vibration generating portion F and the vibration receiving portion R so as to be arranged in the front-rear direction.

As described above, according to the vibration-proof bush 2 according to the present embodiment, the liquid chamber 15 and the orifice passage 16 are provided, and the liquid chambers 15 are arranged in the front-rear direction of the vehicle, and the vibration generating portion F and the vibration receiving portion are arranged. Since it is attached to R, when the vibration generating portion F and the vibration receiving portion R vibrate due to relative displacement in the front-rear direction due to, for example, the tire getting over the protrusion when the vehicle is running, the two liquids. As the chamber 15 expands and contracts, the liquid in the liquid chamber 15 flows through the orifice passage 16 to cause liquid column resonance, and vibration in the front-rear direction can be attenuated and absorbed.

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, as shown in FIG. 5, when the vibration isolator bush 2 is attached to the vibration generating portion F and the vibration receiving portion R and a static load downward is applied to the case cylinder 21, the volume of the air chamber 22 is increased. You may adopt the structure which expands.
In the illustrated example, the first end wall portion 27 is provided on the upper portion of the inner peripheral wall 25, and the second end wall portion 28 is provided on the lower end portion of the outer peripheral wall 26. The second end wall portion 28 is located below the first end wall portion 27. The upper surface of the second end wall portion 28 faces the lower surface of the first end wall portion 27 in the axial direction, and the upper surface of the second end wall portion 28 and the lower surface of the first end wall portion 27 are the air chamber 22. Is defined.
In the above configuration, when the anti-vibration bush 2 is attached to the vibration generating portion F and the vibration receiving portion R and a static load downward is applied to the case cylinder 21, the case cylinder 21, the sliding cylinder 23, and the outer peripheral wall 26 are applied. , And the second end wall portion 28 descends with respect to the outer cylinder 11, the inner peripheral wall 25, and the first end wall portion 27, and the volume of the air chamber 22 expands.

An air tank that communicates with the air chamber 22 and maintains a constant volume may be provided.
In this case, the axial springs of the anti-vibration bushes 1 and 2 can be easily lowered with less space limitation.
A constricted portion may be provided in the middle of the pipe connecting the air chamber 22 and the air tank, and the vibration may be attenuated and absorbed by the flow resistance of the air flowing through the pipe when the vibration in the axial direction is input.
The air chamber 22 may be positioned so as to project upward from the outer cylinder 11 and the case cylinder 21.

The outer peripheral surface of the sliding cylinder 23 may be provided so as to be slidable in the axial direction on the inner peripheral surface of the case cylinder 21, and the inner peripheral surface of the sliding cylinder 23 may be fixed to the outer peripheral surface of the outer cylinder 11. The coefficient of dynamic friction between the outer peripheral surface of the sliding cylinder 23 and the inner peripheral surface of the case cylinder 21 is based on the coefficient of dynamic friction between the outer peripheral surface of the outer cylinder 11 and the inner peripheral surface of the case cylinder 21. It may be smaller.

In addition, it is possible to appropriately replace the components in the above-described embodiment with well-known components without departing from the spirit of the present invention, and the above-described embodiments and modifications may be appropriately combined.

1, 2 Anti-vibration bush 11 Outer cylinder 12 Inner cylinder 14 Elastic body 21 Case cylinder 22 Air chamber 23 Sliding cylinder 25 Inner peripheral wall 26 Outer wall 27 First end wall part 28 Second end wall part F Vibration generating part O Common axis (Central axis)
R vibration receiver

Claims (4)

With the outer cylinder
An inner cylinder that is attached to either the vibration generating part or the vibration receiving part and is arranged inside the outer cylinder, and the inner cylinder.
An elastic body connecting the outer cylinder and the inner cylinder,
A case cylinder that is attached to either one of the vibration generating part and the vibration receiving part, and in which the outer cylinder is arranged so as to be relatively movable in the axial direction along the central axis of the vibration-proof bushing.
A vibration-proof bush comprising an air chamber whose volume expands and contracts as the outer cylinder and the case cylinder move relative to each other in the axial direction. It is provided with a sliding cylinder sandwiched in the radial direction by the outer peripheral surface of the outer cylinder and the inner peripheral surface of the case cylinder.
The outer cylinder and the case cylinder are made of a metal material, and the outer cylinder and the case cylinder are made of a metal material.
The anti-vibration bush according to claim 1, wherein the sliding cylinder is made of a resin material. It is provided with a sliding cylinder sandwiched in the radial direction by the outer peripheral surface of the outer cylinder and the inner peripheral surface of the case cylinder.
One of the outer peripheral surface and the inner peripheral surface of the sliding cylinder is fixed to either the outer peripheral surface of the outer cylinder or the inner peripheral surface of the case cylinder.
One of the outer peripheral surface and the inner peripheral surface of the sliding cylinder is provided on any one of the outer peripheral surface of the outer cylinder and the inner peripheral surface of the case cylinder so as to be slidable in the axial direction. Be,
The coefficient of kinetic friction between any one of the outer peripheral surface and the inner peripheral surface of the sliding cylinder and any other of the outer peripheral surface of the outer cylinder and the inner peripheral surface of the case cylinder is the outer circumference. The vibration-proof bush according to claim 1 or 2, which is smaller than the coefficient of dynamic friction between the outer peripheral surface of the cylinder and the inner peripheral surface of the case cylinder. The outer cylinder is provided with an inner peripheral wall protruding toward one side in the axial direction.
The case cylinder is provided with an outer peripheral wall that projects toward one side in the axial direction and faces the outer peripheral surface of the inner peripheral wall from the outside in the radial direction.
The outer cylinder or the inner peripheral wall is provided with a first end wall portion that protrudes outward in the radial direction and is slidably contacted in the axial direction on the inner peripheral surface of the outer peripheral wall.
A second end wall portion that protrudes inward in the radial direction and is slidably abutted in the axial direction is provided on the outer peripheral surface of the inner peripheral wall of the case cylinder or the outer peripheral wall.
The air chamber is defined by being surrounded by an outer peripheral surface of the inner peripheral wall, an inner peripheral surface of the outer peripheral wall, the first end wall portion, and the second end wall portion. The anti-vibration bush according to any one of 1 to 3.

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