JPH04285339A - Vibration proof device - Google Patents

Abstract

PURPOSE:To improve vibration eliminating operation by elongating the measurement of communication passages which connects liquid chambers. CONSTITUTION:A pressurized liquid chamber 36 is formed on a lower portion of an axial center part of an elastic body 30. A first sub-liquid chamber 40 is formed on an upper portion of the elastic body 30, while a second sub-chamber 44 is formed on an outer peripheral part of the elastic body 30, between the pressurized liquid chamber 36 and the first sub-liquid chamber 40. A first communication passage 52 and a second communication passage 54 are formed on axial both sides of the liquid chambers of the elastic body 30. One side of the first communication passage 52 is connected to the first sub-liquid chamber, at the side of the second sub-liquid chamber 44, while the other side is connected to the pressurized liquid chamber 36, at the side of the second sub-liquid chamber 44. One side of the second communication passage 54 is connected to the second sub-liquid chamber 44, at the side of the pressurized liquid chamber 36, while the other side is connected to the pressurized liquid chamber 36, at the side of the second sub-liquid chamber 44. Since the communication passages are formed on the side directions of the liquid chamber, the passages are connected to the liquid chambers at their most distant portions. The measurement of the communication passages can be thus elongated.

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 shake vibration (vibration with a frequency of less than 15Hz), idle vibration (vibration with a frequency of around 20 to 40Hz), and high-frequency vibration (vibration with a frequency of 80Hz).
A liquid-filled vibration isolator equipped with multiple liquid chambers has been proposed as a vibration isolator that absorbs vibrations in a wide range of frequencies (Japanese Patent Laid-Open No. 2-42).
No. 226, Japanese Unexamined Patent Publication No. 2-42227).

[0003] In this vibration isolator, there are three
The individual liquid chambers are arranged in layers, and the communication passage that connects the liquid chambers to each other is arranged on the other side of the inner cylinder, resulting in a complicated internal structure and complicated manufacturing. In order to effectively absorb the idle vibration of the engine, it is necessary to lengthen the communication path to increase the liquid passage resistance and liquid column resonance, but with this vibration isolator, it is necessary to prevent interference with the liquid chamber. In this case, the dimensions of the communicating path cannot be made long, and the liquid passage resistance and liquid column resonance cannot be increased too much. Although it is conceivable to lengthen the dimensions of the communication path by separately attaching a member that forms the communication path, the structure becomes even more complicated and manufacturing becomes difficult.

0004

SUMMARY OF THE INVENTION In view of the above-mentioned facts, the present invention provides a vibration isolating device which is capable of improving the vibration absorption effect by increasing the dimension of the communication passage connecting the liquid chambers, and which has a simple structure. The purpose is to obtain.

[0005]

[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. , an elastic body provided between the inner tube and the outer tube and deformed when vibration occurs; a plurality of liquid chambers in which the elastic body can be expanded and contracted by using at least part of a partition wall; and the elastic body and the outer tube; A vibration isolator comprising a restriction passage disposed between the liquid chambers and communicating the liquid chambers with each other, the liquid chambers being arranged around the inner cylinder,
It is characterized in that the restriction passages are arranged side by side in the axial direction of the liquid chamber.

[0006]

[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. Vibration is absorbed by resistance based on internal friction of the supported elastic body, and vibration is also absorbed by passage resistance of the liquid flowing through the restricted passage connecting the liquid chambers or liquid column resonance. In addition, since the restriction passages are arranged side by side on the sides of the liquid chambers, the connecting parts of the communication passages that connect the liquid chambers can be set at the farthest positions on the sides of the liquid chambers. The long communication path can increase the liquid passage resistance or the liquid column resonance effect. Furthermore, since the liquid chamber and the communication passage are arranged in parallel, the internal structure is not complicated.

[0007]

[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 has a substantially arc-shaped cross section perpendicular to the axis.

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, 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, 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 communication 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 communication 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 these pressure receiving liquid chamber 36, first sub-liquid chamber 44, second sub-liquid chamber 44, first communication passage 52, and 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), the 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 about ±1 mm), the liquid in the pressure receiving liquid chamber 36 flows into the first communication 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.

[0025] In this way, when two liquid chambers are connected to each other by a communication passage, this communication passage is not interfered with by other liquid chambers. In addition, since the communication path is arranged on the side of the liquid chamber, it is possible to connect the communication path to the part of the two liquid chambers that is the most dimensionally apart from each other. Dimensions corresponding to this can lengthen the communication path. Therefore, the passage resistance and resonance of the liquid in the communication path can be increased, and shake vibrations and idle vibrations can be absorbed more effectively than conventional vibration isolators. Further, a pressure receiving liquid chamber 3 is provided on the outer peripheral side of the elastic body 30.
6. First sub-liquid chamber 40, first sub-liquid chamber 44, first communication passage 52
and the second communicating path 54 are all arranged, so the structure is simple and manufacturing is easy.

[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.
As 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, the dynamic magnification in the high frequency range decreases.

Note that the first communicating path 52 and the second communicating path 54
It is also possible to tune the characteristics of liquid column resonance by varying the cross-sectional area of the liquid column.

In addition, in this embodiment, the movable body 64 is disposed in the pressure receiving liquid chamber 36 to reduce the dynamic magnification in the high frequency range, but the present invention is not limited to this, and the present invention A structure may also be provided in which an absorption means is provided.

[0035]

Since the vibration isolating device of the present invention has the above structure, it has a simple structure and has the excellent effect of increasing the dimension of the communicating path and improving the vibration absorption effect.

[Brief explanation of the drawing]

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.

[Explanation of symbols]

10 Vibration isolation device 16 Outer cylinder 30 Elastic body 31 Inner cylinder 36 Pressure receiving liquid chamber (liquid chamber) 40 First sub-liquid chamber (liquid chamber) 44 Second sub-liquid chamber (liquid chamber) 52 First communication passage (restricted passage) 54 Second communication passage (restricted passage) 70 Second communication passage (restricted passage)

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. an elastic body that is provided and deforms when vibration occurs; a plurality of liquid chambers that are expandable and contractible using the elastic body as at least part of a partition wall; and a plurality of liquid chambers that are disposed between the elastic body and the outer cylinder and communicate the liquid chambers with each other. A vibration isolator comprising a restriction passage, wherein the liquid chamber is arranged in succession around the inner cylinder, and the restriction passage is arranged side by side in the axial direction of the liquid chamber. Device.