JP2012036946A - Vibration isolator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the fall-down of rising walls toward the inside of a groove width direction when externally fitting an outer cylinder to a rubber elastomer.SOLUTION: In the rubber elastomer 13, there are formed a plurality of recesses 14 which define recessed liquid chambers toward the inside of the radial direction in the circumferential direction at intervals, and a communication groove 15 which makes insides of the recesses 14 which are adjacent in the circumferential direction communicate with each other. The outer cylinder 12 is externally fit to the rubber elastomer, the communication groove is defined by a pair of the rising walls 22 which are integrally formed at the rubber elastomer, the communication groove is covered with the outer cylinder, an orifice passage for making the liquid chambers which are adjacent in the circumferential direction communicate with each other is defined, and an external contact part 13c continued to the rising walls from the outside of the groove width direction of the communication groove is located inside the radial direction rather than the bottom face 15a of the communication groove at the outer circumferential surface of the rubber elastomer.

Description

  The present invention relates to a vibration isolator.

As this type of vibration isolator, for example, as shown in Patent Document 1 below, an inner cylinder connected to one of a vibration generating part and a vibration receiving part, an outer cylinder connected to the other, and these A rubber elastic body that elastically connects the two cylinders, and the rubber elastic body is formed with a plurality of hollow portions that define a hollow liquid chamber inward in the radial direction at intervals in the circumferential direction. In addition, a communication groove that connects the insides of the recesses adjacent to each other in the circumferential direction is formed, and the communication groove is covered from the outside in the radial direction by the outer cylinder, so that the liquid chambers adjacent in the circumferential direction communicate with each other. A configuration in which an orifice passage is defined is known.
When vibration is input to the vibration isolator, the elastic body is elastically deformed and the internal volume of each liquid chamber fluctuates, so that the liquid in the liquid chamber flows through the orifice passage and causes liquid column resonance. As a result, vibration is attenuated and absorbed.

JP 2000-170823 A

However, in the conventional vibration isolator, the communication groove is defined by a pair of rising walls formed of a rubber material and projecting outward in the radial direction, and is covered from the outer side in the radial direction by the outer cylinder. Therefore, when the outer cylinder is externally fitted to the rubber elastic body, the rising wall may fall inward in the groove width direction and the groove width may be reduced.
When the groove width of the communication groove is reduced in this way, the flow passage cross-sectional area of the orifice passage becomes insufficient, and it becomes difficult to exhibit the desired vibration isolation performance.

  The present invention has been made in consideration of such circumstances, and can prevent the rising wall from falling inward in the groove width direction when the outer cylinder is externally fitted to the rubber elastic body. An object is to provide a vibration device.

  In order to solve the above-mentioned problems and achieve such an object, the vibration isolator of the present invention is connected to an inner cylinder connected to one of the vibration generator and the vibration receiver, and to the other. And a rubber elastic body that elastically connects both the cylinders, and the rubber elastic body has a recess portion that defines a recess liquid chamber in the circumferential direction. A plurality of grooves are formed at intervals, and a communication groove that communicates the insides of the recesses adjacent in the circumferential direction is formed, and the outer cylinder is fitted to the rubber elastic body to be fitted to the inner cylinder. The communication groove is elastically connected, and the communication groove is formed integrally with the rubber elastic body, and is defined by a pair of rising walls protruding outward in the radial direction, and the communication groove is formed by the outer cylinder. Before adjoining in the circumferential direction by being covered from the outside in the radial direction An orifice passage that communicates between the liquid chambers is defined, and an outer peripheral portion of the rubber elastic body that is connected to the rising wall from the outside in the groove width direction of the communication groove is more radially than the bottom surface of the communication groove. It is located inside.

According to the present invention, the circumscribed portion on the outer peripheral surface of the rubber elastic body is located on the inner side in the radial direction with respect to the bottom surface of the communication groove. The radial size of the outer side surface is larger than the radial size of the inner side surface located on the inner side in the groove width direction.
Therefore, when the outer cylinder is externally fitted to the rubber elastic body, due to the radially inward force applied to the pair of rising walls, these rising walls tend to fall outside rather than inside in the groove width direction. It becomes possible to do.
As a result, it is possible to prevent the communication groove from being narrowed, and the desired vibration-proofing performance can be reliably exhibited.

  Here, a circumferential groove may be formed in the circumscribed portion on the outer peripheral surface of the rubber elastic body.

  In this case, since the peripheral groove is formed in the circumscribed portion on the outer peripheral surface of the rubber elastic body, for example, the above-described effects can be achieved even if the depth of the communication groove is not reduced but is maintained at the same level as the current one. The vibration isolator can be easily switched from the current vibration isolator.

  According to the vibration isolator which concerns on this invention, when an outer cylinder is externally fitted to a rubber elastic body, it can suppress that a rising wall falls down toward the inner side of a groove width direction.

It is a transverse cross section in the central part of the direction of an axis of a vibration isolator shown as one embodiment concerning the present invention. It is AA arrow sectional drawing of the vibration isolator shown in FIG. In the vibration isolator shown in FIG. 1 and FIG. 2, it is the side view which looked at one coating | coated member from the front in the state which removed the outer cylinder. In the vibration isolator shown in FIG. 1 and FIG. 2, it is the side view which looked at the other coating | coated member from the front in the state which removed the outer cylinder. It is a principal part enlarged view of the vibration isolator shown in FIG. 1 and FIG. It is a principal part enlarged view of the vibration isolator shown as other embodiment which concerns on this invention.

Hereinafter, an embodiment of a vibration isolator according to the present invention will be described with reference to FIGS. 1 to 5.
The vibration isolator 1 according to the present embodiment includes an inner cylinder 11 connected to one of a vibration generator and a vibration receiver, an outer cylinder 12 connected to the other, and both the cylinders 11 and 12. A rubber elastic body 13 that is elastically connected.
The vibration isolator 1 is used as, for example, a suspension bush for an automobile, an engine mount, or a mount for an industrial machine installed in a factory.
The inner cylinder 11 and the outer cylinder 12 are arranged coaxially with the common axis. Hereinafter, this common axis is referred to as an axis O, a direction orthogonal to the axis O is referred to as a radial direction, and a direction around the axis O is referred to as a circumferential direction.

The inner cylinder 11 is a cylindrical body extending along the direction of the axis O, and has a curved surface protruding toward the outside in the radial direction in a longitudinal sectional view as shown in FIG. A bulging portion 11a is formed to protrude over the entire circumference. Note that the inner diameter of the inner cylinder 11 is the same over the entire length in the axis O direction.
The rubber elastic body 13 is formed in a cylindrical shape from a rubber material, and an inner peripheral surface thereof is bonded to the outer peripheral surface of the inner cylinder 11 over the entire area excluding both end portions in the axis O direction. The rubber elastic body 13 is vulcanized and bonded to the outer peripheral surface of the inner cylinder 11. On the other hand, the outer cylinder 12 is elastically connected to the inner cylinder 11 by being externally fitted to the rubber elastic body 13.

The rubber elastic body 13 is formed with a plurality of recess portions 14 that define a recess liquid chamber inward in the radial direction at intervals in the circumferential direction, and the insides of the recess portions 14 that are adjacent in the circumferential direction. A communication groove 15 that communicates with each other is formed.
As shown in FIG. 1, two depressions 14 are formed in the rubber elastic body 13, and are arranged separately on both sides sandwiching the axis O in the radial direction. The two recessed portions 14 have the same shape and the same size, and have a rectangular shape that is long in the circumferential direction when viewed from the side of the rubber elastic body 13 viewed from the outside in the radial direction.
The communication groove 15 is formed in the outer peripheral surface of one circumferential part 13a among the two circumferential parts 13a and 13b located between the two depressions 14 in the rubber elastic body 13, and extends along the circumferential direction. It is extended. The communication groove 15 is formed integrally with the rubber elastic body 13 and is defined by a pair of rising walls 22 protruding outward in the radial direction. Further, the communication groove 15 is disposed in the central portion of the outer peripheral surface of the rubber elastic body 13 in the direction of the axis O. The groove width of the communication groove 15 gradually increases from the inner side to the outer side in the radial direction.

A reinforcing body 16 is embedded in the rubber elastic body 13.
The reinforcing body 16 is separately disposed at both ends of the rubber elastic body 13 in the direction of the axis O, the reinforcing ring 16a extending over the entire circumference, and the axes of the two circumferential portions 13a and 13b of the rubber elastic body 13. And a reinforcing plate 16b disposed in a portion located on the inner side in the radial direction of the reinforcing ring 16a in the intermediate portion in the O direction. The reinforcing ring 16a and the reinforcing plate 16b are integrally formed.

In the illustrated example, a covering member 17 formed of a material harder than the material forming the rubber elastic body 13 is fitted into each of the recessed portions 14 so that the recessed portions 14 are formed from the outside in the radial direction. A liquid chamber is defined.
The covering member 17 is made of, for example, a synthetic resin material. The covering member 17 is formed with a communication opening 18 that penetrates in the radial direction, and a connection groove 19 that connects the communication opening 18 and the communication groove 15.

In this embodiment, as shown in FIGS. 3 and 4, the communication opening 18 is one side adjacent to the outer end portion on the recess 14 side in the communication groove 15, of both ends in the circumferential direction of the covering member 17. Is formed at the other end opposite to the other end. The communication opening 18 is located at one end of the covering member 17 in the direction of the axis O.
The connecting groove 19 is located on the other side in the axis O direction from the first groove 19a at the end on one side in the circumferential direction of the covering member 17 from the communication opening 18 toward the one side in the circumferential direction. The second groove 19b formed in the portion to be connected to the outer end portion of the communication groove 15 and the both grooves 19a and 19b are connected to each other and gradually from the other side in the circumferential direction toward the one side in the axis O direction. A third groove 19c extending from one side to the other side. As a result, the connection groove 19 that connects the communication opening 18 and the communication groove 15 extends over substantially the entire length of the covering member 17 in the circumferential direction.

In the example shown here, the covering member 17 has a dummy opening D1 that is point-symmetric with the communication opening 18 with respect to the center of the covering member 17 in a front view when the covering member 17 is viewed from the outside in the radial direction. A dummy groove D2 that is point-symmetric with the connection groove 19 is formed.
Then, the end of the dummy groove D2 opposite to the dummy opening D1 is a portion of the opening of the recess 14 that faces the communication groove 15 in the circumferential direction, that is, the two circumferential portions 13a of the rubber elastic body 13. 13 b is closed by the peripheral end of the other circumferential portion 13 b where the communication groove 15 is not formed.

In the above configuration, the communication groove 15, the communication opening 18, and the connection groove 19 are covered from the outside in the radial direction by the outer cylinder 12, thereby defining an orifice passage that communicates the liquid chambers adjacent in the circumferential direction. Has been. In the illustrated example, the orifice passage extends over the entire circumference except for the other circumferential portion 13 b of the rubber elastic body 13.
When vibration is input to the vibration isolator 1, the rubber elastic body 13 is elastically deformed, and the internal volume of each liquid chamber varies, so that the liquid in the liquid chamber flows through the orifice passage and the liquid column. By causing resonance, vibration is attenuated and absorbed.

  Here, not only the communication opening 18 and the connection groove 19 but also the dummy opening D1 and the dummy groove D2 are provided in each covering member 17, so that the covering members 17 fitted in the two depressions 14 can be connected to each other. It is possible to make the same shape and the same size, and when fitting the covering member 17 to the recessed portion 14, it is possible to match the inner peripheral edge of the recessed portion 14 and the outer peripheral edge of the covering member 17 without matching the other directions. However, a vibration isolator having the same length of the orifice passage can be obtained.

In the present embodiment, as shown in FIG. 5, on the outer peripheral surface of the rubber elastic body 13, a circumscribed portion 13 c that continues to the rising wall 22 from the outside in the groove width direction is formed from the bottom surface 15 a of the communication groove 15. Is also located on the inside in the radial direction. As a result, of the both side surfaces of the rising wall 22, the radial size of the outer side surface 22 b located outside the groove width direction is larger than the radial size of the inner side surface 22 a located inside the groove width direction. It has become.
In addition, before the outer cylinder 12 is fitted on the rubber elastic body 13, the rising angle of the outer surface 22 b of the rising wall 22 from the circumscribed portion 13 c on the outer peripheral surface of the rubber elastic body 13 is The inner surface 22 a is smaller than the rising angle from the bottom surface 15 a of the communication groove 15. For example, the outer surface 22 b of the rising wall 22 is substantially perpendicular to the circumscribed portion 13 c on the outer peripheral surface of the rubber elastic body 13 before the outer cylinder 12 is fitted on the rubber elastic body 13. The inner side surface 22a is inclined so that the groove width of the communication groove 15 gradually increases from the inner side to the outer side in the radial direction.

As described above, according to the vibration isolator 1 according to the present embodiment, the circumscribed portion 13c on the outer peripheral surface of the rubber elastic body 13 is located on the radially inner side with respect to the bottom surface 15a of the communication groove 15, Since the radial size of the outer side surface 22 b of the rising wall 22 is larger than the radial size of the inner side surface 22 a, when the outer cylinder 12 is externally fitted to the rubber elastic body 13, the pair of rising walls 22. Due to the radially inwardly applied force applied to, it is possible to make these rising walls 22 easily fall outside rather than inside in the groove width direction.
Thereby, it becomes possible to prevent the groove width of the communication groove 15 from being narrowed, and the desired vibration isolating performance can be reliably exhibited.

  In addition, since the recess 14 is covered with the covering member 17 in which the communication opening 18 and the connection groove 19 are formed, the liquid chamber is defined, so that the recess 14 is not the covering member 17 but the outer cylinder 12. Compared to the vibration isolator that covers the liquid chamber, the length of the orifice passage can be secured easily, and the frequency at which the liquid column resonance occurs, that is, tuning is easy. It can be carried out.

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

For example, in the above embodiment, the dummy opening D1 and the dummy groove D2 are disposed in the covering member 17, but these D1 and D2 may not be provided.
Further, the covering member 17 may not be provided. That is, the liquid chamber is defined by the depression 14 being covered with the covering member 17, but the liquid chamber is defined by the depression 14 being covered by the outer cylinder 12 instead of the covering member 17. You may make it be made.
Further, as shown in FIG. 6, a circumferential groove may be formed in the circumscribed portion 13 c on the outer peripheral surface of the rubber elastic body 13.
In this case, since the circumferential groove is formed in the circumscribed portion 13c on the outer peripheral surface of the rubber elastic body 13, for example, the above-described effects can be obtained even if the depth of the communication groove 15 is not reduced but is maintained at the same level as the current one. It is possible to succeed, and the vibration isolator 2 can be easily switched from the current vibration isolator.

  In addition, it is possible to appropriately replace the constituent elements in the above-described embodiments with well-known constituent elements without departing from the gist of the present invention, and the above-described modified examples may be appropriately combined.

  When the outer cylinder is externally fitted to the rubber elastic body, the rising wall can be prevented from falling toward the inside in the groove width direction.

DESCRIPTION OF SYMBOLS 1, 2 Vibration isolator 11 Inner cylinder 12 Outer cylinder 13 Rubber elastic body 13c Outer part 14 Indentation part 15 Communication groove 15a Bottom face 22 Standing wall

Claims (2)

An inner cylinder connected to one of the vibration generator and the vibration receiver, and an outer cylinder connected to the other,
A rubber elastic body that elastically connects both the cylinders,
The rubber elastic body is formed with a plurality of recessed portions defining a recessed liquid chamber inward in the radial direction at intervals in the circumferential direction, and the insides of the recessed portions adjacent to each other in the circumferential direction. A communication groove that communicates is formed,
The outer cylinder is elastically connected to the inner cylinder by being externally fitted to the rubber elastic body,
The communication groove is integrally formed with the rubber elastic body, and is defined by a pair of rising walls protruding outward in the radial direction,
The communication groove is covered from the outside in the radial direction by the outer cylinder, thereby defining an orifice passage that connects the liquid chambers adjacent in the circumferential direction.
In the outer peripheral surface of the rubber elastic body, a circumscribed portion connected to the rising wall from the outside in the groove width direction of the communication groove is located on the inner side in the radial direction from the bottom surface of the communication groove. Shaker. The vibration isolator according to claim 1,
A vibration isolator having a circumferential groove formed in the circumscribed portion of the outer peripheral surface of the rubber elastic body.

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