JPH04296235A - Vibration isolator - Google Patents

Abstract

PURPOSE:To secure such a vibration isolator that produces no variation in a vibro-proofing characteristic according to the mounting direction. CONSTITUTION:An elastic body 30 is installed in the inner part of an outer cylinder 16. A recess 34 is formed in a lower part of this elastic body 30, and a pressure liquid chamber 36 is formed by this recess 34 and the outer cylinder 16. A movable body 64 formed by this elastic body is installed in the pressure liquid chamber 36, and a tip of a support leg 66 of this movable body 64 is inserted into a recess 68 formed in and around an opening of the recess 34, holding it between the outer cylinder 16 and the elastic body 30. In addition, a liquid such as oil or the like is filled up in the liquid chamber 36. Since the movable body 64 is supported by the support leg 66, size in a clearance between a movable part 65 and a wall surface of the pressure liquid chamber is in no case changed by a sense of installation of the vibration isolator 10. Therefore, flow resistance of the liquid lying between the movable part 65 and the wall surface of the pressure liquid chamber 36 or resonance frequency will not vary according to the mounting sense as well.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-filled vibration isolator that absorbs vibrations from vibration-generating parts such as engines.

0002

2. Description of the Related Art A vibration isolating device serving as an engine mount is disposed between the engine and the vehicle body of an automobile, and is designed to prevent engine vibrations from being transmitted to the vehicle body. Engine vibrations include low-frequency vibrations and high-frequency vibrations, and a liquid-filled vibration isolator has been proposed as a vibration isolator that effectively absorbs both (Japanese Unexamined Patent Publication No. 2-8529).

In this vibration isolator, a movable member that can freely move a predetermined distance is housed inside the liquid chamber, and when vibration is input, the movable member is separated from the bottom of the liquid chamber due to the flow of liquid, and the movable member is moved. The dynamic spring of the vibration isolator is reduced by the liquid flow resistance or resonance between the member and the liquid chamber wall.

By the way, since this vibration isolator does not have any means for supporting the movable member, the dimensions between the movable member and the liquid chamber wall surface vary and are not constant depending on the mounting direction of the vibration isolator. The frequency at which the fluid resonates is related to the dimensions between the movable member and the liquid chamber wall surface, and when this dimension changes, the resonance frequency changes, and the resonance frequency deviates from the frequency that should be attenuated, resulting in a change in the frequency at the desired frequency. A problem occurs in which the dynamic spring is not sufficiently reduced.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned facts, the present invention aims to provide a vibration isolating device whose vibration isolating characteristics do not change depending on the mounting direction.

[0006]

[Means for Solving the Problems] The vibration isolator of the present invention has an inner cylinder connected to one of the vibration generating part and the vibration receiving part, and an outer cylinder connected to the other of the vibration generating part and the vibration receiving part. , a vibration isolator comprising: an elastic body provided between the inner cylinder and the outer cylinder and deformed when vibration occurs; and a liquid chamber that can be expanded and contracted using the elastic body as at least a part of a partition wall, a movable body disposed inside the liquid chamber and a part of which is spaced a predetermined distance from an inner wall within the liquid chamber; one side connected to the movable body and the other side connected to the outer cylinder to support the movable body; It is characterized by having elastic support legs.

[0007]

[Operation] In the vibration isolating device of the present invention, for example, when the outer cylinder is connected to the vibration receiving part and the inner cylinder is connected to the vibration generating part, the vibration transmitted from the vibration generating part is transmitted to the outer cylinder through the elastic body. It is supported, and vibrations are absorbed by resistance based on internal friction of the elastic body. Furthermore, in this vibration isolator, the liquid between the movable body and the wall surface of the liquid chamber flows due to vibration input, so the dynamic spring constant is reduced due to liquid passage resistance or resonance. Further, since the movable body is supported by the support legs, there is no fear that the position of the movable body will be biased within the liquid chamber depending on the mounting direction of the vibration isolator, and the distance between the wall surface of the liquid chamber and the movable body will change. Therefore, the flow resistance or resonance frequency experienced by the liquid between the wall surface of the liquid chamber and the movable body can be kept constant, and changes in vibration damping characteristics can be prevented.

[0008]

[Embodiments] [First Embodiment] A vibration isolating device 10 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 8.

As shown in FIG. 1, this vibration isolator 10 is equipped with a mounting frame 12 (not shown) for mounting on a vehicle body, and an outer cylinder 16 is inserted into an annular portion 14 of this mounting frame 12. There is. Note that this outer cylinder 16 is connected to the annular portion 1.
Both ends of 4 are fixed to the annular portion 14 by drawing inward.

As shown in FIGS. 1 and 2, the outer cylinder 16 has a pair of rectangular holes 18 formed on its upper side, and a pair of small rectangular holes 20 formed on its lower side. Further, a thin rubber layer 22 is vulcanized and bonded to the inner peripheral surface of the outer cylinder 16, and portions of this thin rubber layer 22 corresponding to the rectangular holes 18 protrude inward to form a diaphragm 24, and a small A portion corresponding to the rectangular hole 20 projects inward to form a membrane 26. Note that the membrane 26 is the diaphragm 2.
It is formed thicker than 4 and has high rigidity.

An intermediate cylinder 28 is disposed coaxially inside the outer cylinder 16. The intermediate cylinder 28 is made of a steel plate, and as shown in FIGS. 3A and 3B, a pair of rings each having a substantially U-shaped cross section are connected to each other by a substantially semicircular connecting plate.

As shown in FIG. 4, an elastic body 30 is vulcanized and bonded to the intermediate cylinder 28, and an inner cylinder 31 is disposed approximately at the center of the elastic body 30 along the axis. The intermediate cylinder 28 is fixed to the outer cylinder 16 by drawing both ends of the outer cylinder 16 inward.

A recess 34 is formed in the elastic body 30 at the lower side of the inner cylinder 31 and at the middle part in the axial direction.
4 and the outer cylinder 16 form a pressure receiving liquid chamber 36. As shown in FIG. 5, the bottom surface 35 of the recess 34 serves as an inner wall.
The cross section perpendicular to the axis is formed in a substantially arc shape.

A movable body 64 made of an elastic material such as rubber is disposed in the pressure receiving liquid chamber 36 . The movable body 64 includes a movable part 65 and a pair of support legs 66 extending from the lower part of the movable part 65. The upper surface of the movable portion 65 has a shape corresponding to the bottom surface 35 of the recess 34 when viewed from the direction along the axis, and is formed so as to gradually separate from the bottom surface 35 as it approaches the side wall 37 of the recess 34. has been done. Further, the tip of the support leg 66 is inserted and fixed into a recess 68 formed near the opening of the recess 34. The movable portion 65 is biased toward the bottom surface 35 of the recess 34 by the biasing force of the support legs 66, and the center portion of the top surface of the movable portion 65 is lightly pressed against the bottom surface 35. Further, as shown in FIG. 5, the movable part 65 has side walls 39 of the recess 34 on both sides in the axial direction.
It is spaced a predetermined distance from.

On the other hand, on the upper side of the elastic body 30, as shown in FIG. A first sub-liquid chamber 40 is formed therein. Further, the space between the diaphragm 24 and the outer cylinder 16 is an air chamber. This air chamber may be communicated with the outside by forming a hole (not shown) in the annular portion 14 of the mounting frame 12.

Furthermore, the elastic body 30 has a recess 34 on the outer periphery.
A pair of left and right small recesses 42 are formed between the recess 38 and the recess 38, and a second sub-liquid chamber is formed between the small recess 42 on the right side in FIG. 44 is formed, and a small recess 42 on the left side of FIG. 5 (in the direction of arrow A in FIG. 5)
A dummy liquid chamber 46 is formed by the outer cylinder 16 and the outer cylinder 16 . Further, the space between the membrane 26 and the outer tube 16 may be an air chamber, and a hole (not shown) may be formed in the annular portion 14 of the mounting frame 12 to communicate with the outside.

As shown in FIG. 6, annular grooves 48 and 50 are formed on both sides of the recess 34, recess 38, and small recess 42 in the axial direction by rings of the intermediate cylinder 28, and these annular grooves 48 and 50 They are blocked from the outside by being closed by the outer cylinder 16, and the left side in FIG. 6 (in the direction of arrow C in FIG. 6) is the first communication path 52, and the right side in FIG. 6 (in the direction of arrow D in FIG. 6) is the second communication path 54. It is said that

As shown in FIG. 7, the first communication passage 52 is partially closed by the elastic body 30 and has a C-shaped cross section perpendicular to the axis, with one end connected to the second part of the pressure receiving liquid chamber 36. Sub-liquid chamber 4
The other end communicates with the pressure-receiving liquid chamber 36 through a hole 56 formed at the end of the first sub-liquid chamber 40 and the second sub-liquid chamber 44 . 1 sub-liquid chamber 40
It communicates with

As shown in FIG. 8, the second communicating passage 54 is partially closed by the elastic body 30 and has a C-shaped cross section perpendicular to the axis, with one end connected to the second communicating passage 54 of the pressure receiving liquid chamber 36. Sub-liquid chamber 4
The hole 60 formed at the fourth side end communicates with the pressure receiving liquid chamber 36, and the other end communicates with the pressure receiving liquid chamber 36 of the second sub liquid chamber 44.
It communicates with the second sub-liquid chamber 44 through a hole 62 formed at the 6th side end.

Note that the pressure receiving liquid chamber 36, the first sub-liquid chamber 44, the second sub-liquid chamber 44, the first communication passage 52, and the second communication passage 54 are filled with liquid such as water or oil. .

Next, the operation of the first embodiment will be explained.

When the frame 12 is attached to a vehicle body (not shown) and the inner cylinder 31 is connected to an engine (not shown), vibrations of the engine are supported by the vehicle body (not shown) via the inner cylinder 31, the elastic body 30, the outer cylinder 16, and the frame 12. Ru. At this time,
The elastic body 30 is elastically deformed and engine vibrations are absorbed by a damping effect based on internal friction.

When the vibration of the engine is relatively low frequency (for example, shake vibration with a frequency of less than 15 Hz and an amplitude of approximately ±1 mm), the liquid in the pressure receiving liquid chamber 36 flows into the first communicating path 5.
2 to and from the first sub-liquid chamber 44. At this time, the membrane 26 of the second sub-liquid chamber 44 hardly deforms, and the volume of the second sub-liquid chamber 44 changes little, and no liquid flows through the second communication path 54. This is because the membrane 26 of the second sub-liquid chamber 44 has higher rigidity than the diaphragm 24 of the first sub-liquid chamber 40. Therefore, the shake vibration is absorbed by the passage resistance of the liquid in the first communicating path 52 or by the liquid column resonance.

When the vibration frequency of the engine becomes a little higher (
For example, if the idle vibration is from 20 to 40 Hz, the first communication passage 52 becomes clogged. Therefore, the pressure receiving liquid chamber 36
The liquid passes through the second communication path 54, deforms the membrane 26, and flows back and forth between the pressure-receiving liquid chamber 36 and the second sub-liquid chamber 44. The idle vibration is absorbed by the passage resistance of the liquid in the second communication path 54 or by liquid column resonance.

Furthermore, when the vibration frequency of the engine becomes higher (for example, high frequency vibration of 80 Hz or more that causes muffled noise), the second communication passage 54 also becomes clogged.
When the liquid resonates between the movable body 64 and the inner wall of the pressure-receiving liquid chamber 36, the dynamic magnification in the high frequency range decreases. Moreover, since the movable body 64 is supported by the support legs 66, even if the vibration isolator 10 is installed obliquely, the gap between the wall surface of the pressure receiving liquid chamber 36 and the movable part 65 hardly changes. Therefore, the vibration damping characteristics do not change depending on the mounting direction.

[Second Embodiment] A vibration isolating device 10 according to a second embodiment of the present invention will be explained with reference to FIGS. 9 and 10. Note that the same components as those in the first embodiment are given the same reference numerals and their explanations will be omitted.

As shown in FIG. 9, the second communication passage 70 of the second embodiment has a C-shaped cross section perpendicular to the axis, and one end is connected to the second sub-section as shown in FIGS. 9 and 10. The liquid chamber 44 communicates with the second sub-liquid chamber 44 through a hole 72 formed at the end thereof on the side of the first sub-liquid chamber 40 , and the other end communicates with the second sub-liquid chamber 44 of the first sub-liquid chamber 40 . It communicates with the first sub-liquid chamber 40 through a hole 74 formed at the side end.

That is, in the vibration isolator 10 of the second embodiment, the liquid in the pressure receiving liquid chamber 36 flows through the second communication passage 54 and the second auxiliary liquid chamber 44.
, are connected to the first sub-liquid chamber 40 via the first communication passage 52 in this order.

Next, the operation of the second embodiment will be explained.

When the vibration of the engine is relatively low frequency (for example, shake vibration with a frequency of less than 15 Hz and an amplitude of approximately ±1 mm), the pressure in the pressure receiving liquid chamber 36 increases due to the vibration, causing the liquid in the pressure receiving liquid chamber 36 to It goes back and forth with the first auxiliary liquid chamber 40 via the two communication passage 54, the second auxiliary liquid chamber 44, and the first communication passage 52. The shake vibration is absorbed by the passage resistance or liquid column resonance between the pressure-receiving liquid chamber 36 and the first sub-liquid chamber 40 . Furthermore, since the dimension from the pressure receiving liquid chamber 36 to the first sub-liquid chamber 40 is long, the damping effect of shake vibration is greater than that of the vibration isolator 10 of the first embodiment.

When the vibration frequency of the engine becomes a little higher (
Although the first communication passage 52 (for example, idle vibration of 20 to 40 Hz) becomes clogged, the liquid in the pressure-receiving liquid chamber 36 flows back and forth to the second sub-liquid chamber 44 via the second communication passage 54. The idle vibration is absorbed by the passage resistance of the liquid in the second communication path 54 or by liquid column resonance.

Furthermore, when the vibration frequency of the engine becomes higher (for example, high frequency vibration of 80 Hz or more that causes muffled noise), the second communication passage 54 also becomes clogged.
The liquid in the pressure receiving liquid chamber 36 moves back and forth between the movable body 64 and the inner wall of the pressure receiving liquid chamber 36, thereby reducing the dynamic magnification in the high frequency range.

[Third Embodiment] A third embodiment of the present invention is shown in FIG.
1A and B. Note that the same components as those in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted.

In the movable body 64 of the third embodiment, a pair of bead portions 82 are formed on the upper surface of the movable portion 65 and a part of the side surface in the direction of the arrows C and D in the figure in the direction along the directions of the arrows C and D in the figure. ing. Therefore, the movable body 64 of the third embodiment
There is no surface contact with a wall surface (not shown). Further, by adjusting the height of the bead portion 82, a gap of a predetermined size can be provided above the movable body 64, and the flow resistance or resonance characteristics of the liquid can be tuned.

[Fourth Embodiment] A fourth embodiment of the present invention is shown in FIG.
2 will be explained. Note that the same components as those in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted.

As shown in FIG. 12, the movable body 80 of the fourth embodiment differs from the movable body 64 of the first embodiment in that a reinforcing layer 79 made of cloth or long fibers such as synthetic fibers is embedded inside. ing.

[Fifth Embodiment] The fifth embodiment of the present invention is shown in FIG.
This will be explained according to 3. Note that the same components as those in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted.

As shown in FIG. 13, the movable body 64 of the fifth embodiment differs from the movable body 64 of the first embodiment in that the movable body 64 has support legs 66.
The distal end portion of the elastic body 38 is vulcanized and bonded to the center portion of a curved plate 80 which is clamped and fixed between the outer cylinder 20 and the elastic body 38 .

[Sixth Embodiment] A sixth embodiment of the present invention is shown in FIG.
4 will be explained. This embodiment is a modification of the fifth embodiment, and the same components as those in the fifth embodiment are denoted by the same reference numerals, and the explanation thereof will be omitted.

As shown in FIG. 14, in the movable body 64 of the sixth embodiment, a steel plate 84 having a U-shaped cross section is embedded inside the movable portion 65. As shown in FIG. Further, the support leg 66 has an X-shaped cross section perpendicular to the axis, and one end is connected to the center of the bottom surface of the recess 86 of the movable part 65, and the other end is connected to the curved plate 8.
It is vulcanized and bonded to 0. In the vibration isolator 10 of the sixth embodiment, when the inner cylinder 31 is largely deviated downward and the movable part 65 is largely moved downward, the support leg 66 is folded inward into the recess 86 of the movable part 65. Therefore, there is no fear that the support leg 66 will be crushed by the movable part 65.

[Seventh Embodiment] The seventh embodiment of the present invention is shown in FIG.
The explanation will be given according to 5A and 5B. This embodiment is a modification of the fifth embodiment, and the same components as those in the fifth embodiment are denoted by the same reference numerals, and the explanation thereof will be omitted.

As shown in FIG. 15A, in the movable body 64 of the seventh embodiment, a movable portion 65 is formed into a box shape by pressing a metal plate. As shown in FIG. 15B, one side of a rubber ring 88 having a circular cross section perpendicular to the axis is vulcanized and bonded to the recess 86 of the movable part 65.
8 is vulcanized and bonded to the curved plate 80.

[Eighth Embodiment] The eighth embodiment of the present invention is shown in FIG.
6 will be explained. This embodiment is a modification of the seventh embodiment, and the same components as those in the seventh embodiment are denoted by the same reference numerals, and the explanation thereof will be omitted.

As shown in FIG. 16, in the movable body 64 of the eighth embodiment, a movable portion 65 is supported by a rectangular rubber ring 90. As shown in FIG. The rectangular rubber ring 90 has a substantially rectangular cross section perpendicular to its axis, and the supporting parts 92 are bent in a direction in which the central parts thereof approach each other. Further, the rectangular rubber ring 90 has an upper surface vulcanized and bonded to the bottom surface of the recess 86 of the movable portion 65.
The lower surface is vulcanized and bonded to the center of the curved plate 80.

[0045]

Effects of the Invention Since the vibration isolating device of the present invention has the above structure, it has an excellent effect that the vibration isolating characteristics do not change depending on the mounting direction.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing a vibration isolator according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG. 1, showing an outer cylinder and a thin rubber layer of the vibration isolator according to the first embodiment of the present invention.

3 shows an intermediate cylinder of the vibration isolator according to the first embodiment of the present invention, where A is a cross-sectional view taken along line IIIA-IIIA in FIG. 3B, and B is a cross-sectional view taken along line IIIB-IIIB in FIG. 3A.

4 shows a vibration isolator according to a first embodiment of the present invention, and is a cross-sectional view taken along the line IV-IV in FIG. 5. FIG.

5 shows a vibration isolator according to a first embodiment of the present invention, and is a cross-sectional view taken along the line V-V in FIG. 4. FIG.

FIG. 6 is a partial sectional view corresponding to FIG. 4, showing a vibration isolating device according to a first embodiment of the present invention.

7 shows a vibration isolator according to a first embodiment of the present invention, and is a sectional view taken along the line VII-VII in FIG. 6. FIG.

8 shows a vibration isolator according to a first embodiment of the present invention, and is a sectional view taken along the line VIII-VIII in FIG. 6. FIG.

9 shows a vibration isolator according to a second embodiment of the present invention, and is a sectional view taken along the line IX-IX in FIG. 10. FIG.

FIG. 10 is a partial cross-sectional view showing a vibration isolator according to a second embodiment of the present invention.

11A is a perspective view showing a movable body of a vibration isolator according to a third embodiment of the present invention, and B is a perspective view showing XIB-XI of FIG. 11A.
It is a sectional view taken along line B.

FIG. 12 is a sectional view showing a movable body of a vibration isolator according to a fourth embodiment of the present invention.

FIG. 13 is a sectional view showing a vibration isolator according to a fifth embodiment of the present invention.

FIG. 14 is a sectional view showing a vibration isolator according to a sixth embodiment of the present invention.

FIG. 15A is a perspective view showing a movable body of a vibration isolator according to a seventh embodiment of the present invention, and FIG. 15B is a perspective view showing a vibration isolator according to a seventh embodiment of the present invention.

FIG. 16 is a sectional view showing a vibration isolator according to an eighth embodiment of the present invention.

[Explanation of symbols]

10 Vibration isolation device 16 Outer cylinder 30 Elastic body 31 Inner cylinder 35 Bottom (inner wall) 36 Pressure receiving liquid chamber (liquid chamber) 40 First sub-liquid chamber (liquid chamber) 44 Second sub-liquid chamber (liquid chamber) 64 Movable body 66 Support legs 88 Rubber ring (support leg)

Claims (1)

[Claims] 1. An inner cylinder connected to one of the vibration generating part and the vibration receiving part, an outer cylinder connected to the other of the vibration generating part and the vibration receiving part, and between the inner cylinder and the outer cylinder. A vibration isolating device comprising an elastic body that is provided and deforms when vibration occurs, and a liquid chamber that is expandable and contractible using the elastic body as at least a part of a partition wall, the vibration isolator being disposed inside the liquid chamber and a part of which is A movable body disposed at a predetermined distance from an inner wall in a liquid chamber, and support legs having elasticity, one of which is connected to the movable body, the other of which is connected to the outer cylinder, and supports the movable body. Featured vibration isolation device.