JPH04302731A - Liquid sealing type vibration isolation device - Google Patents

Abstract

PURPOSE:To suppress a deterioration of an elastic body owing to the contact of the elastic body and a partition plate, and to suppress a deterioration of the vibration-proof function, in a liquid sealing type vibration isolation device. CONSTITUTION:Near the center of a recess 12 formed to an elastic body 4, two thick wall parts 20a and 20b making almost symmetric laterially, making the longitudinal line of an inner tube 1 as the center line, are formed, and a valley 19 extending in the longitudinal direction of the inner tube 1, positioning between the two thick wall parts 20a and 20b, have been formed. As a result, when a vibration of the inner tube 1 is increased, and the elastic body 4 is contacted to the partition plate 22, both two thick wall parts 20a and 20b formed near the center of the recess 12 of the elastic body 4 are contacted to the partition plate 20. As a result, a stress from the inner tube 1 is dispersed to the thick wall parts 20a and 20b, but not concentrated at one part, and the deterioration of the elastic body 4 can be suppressed.

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 damping device used, for example, to support a vehicle engine on a vehicle body.

0002

2. Description of the Related Art Generally, a vehicle engine is supported by a vehicle body through a vibration isolating device to suppress transmission of engine vibrations to the vehicle body. As this vibration isolator, there is a liquid-filled vibration isolator that is filled with liquid.

FIG. 4 is a sectional view of an example of a liquid-filled vibration isolator, and FIG. 5 is a sectional view taken along line BB in FIG.

4 and 5, reference numeral 1 denotes an inner cylinder, and this inner cylinder 1 is attached to an engine or a vehicle body via a rod or the like (not shown). 3 is an outer cylinder, and this outer cylinder 3
is attached to the vehicle body or engine via a bracket 2. 4 is an elastic body for vibration absorption, and this elastic body 4 is attached between the inner cylinder 1 and the outer cylinder 3.

Further, the elastic body 4 is vulcanized and bonded to the outer circumference of the inner cylinder 1, and a recess 12 is formed in a part of the outer circumferential surface of the elastic body 4. A partition plate 13 is disposed in this recess 12, and the partition plate 13 divides the recess 12 into a main fluid chamber 7a and a sub-fluid chamber 7b. This recess 1
The center portion of 2 is a thick portion 21. One end of the partition plate 13 is in close contact with the inner peripheral surface of the outer cylinder 3. 14 is a cavity formed in the elastic body 4, and this cavity 14 is connected to the inner cylinder 1.
extends along the axial direction.

Reference numeral 15 denotes a metal cylinder vulcanized and bonded to the outer peripheral surface of the elastic body 4, and a portion of the metal cylinder 15 corresponding to the recess 12 of the elastic body 4 is cut out in the shape of a window. Further, 6 is an orifice, and this orifice 6 is formed on the outer peripheral surface of the barrel metal 15, and the main fluid chamber 7a and the sub-fluid chamber 7b are communicated through the orifice 6.

Reference numeral 5 denotes a diaphragm, and this diaphragm 5 is formed along the inner circumferential surface of the outer cylinder 3, and the space between the diaphragm 5 and the partition plate 13 forms an auxiliary fluid chamber 7b. 8 is an air chamber, and this air chamber 8 is connected to the diaphragm 5.
and the inner peripheral surface of the bracket 2. Further, 10 is a through hole formed in the outer cylinder 3, and 9 is a ventilation hole formed in the bracket 2. The ventilation hole 9 and the through hole 10 serve as an air passage for the air chamber 8. 1
1a and 11b are openings formed in the outer tube 3 as shown in FIG. 6, and the through hole 10 is formed between the openings 11a and 11b. Note that this opening 11
a and 11b are for facilitating the work of attaching the diaphragm 5 to the inner peripheral surface of the outer cylinder 3.

[0008]Fluid such as silicone oil is sealed in the main fluid chamber 7a and the auxiliary fluid chamber 7b.

In the liquid-filled vibration isolator constructed as described above, when the inner cylinder 1 vibrates due to engine vibration and the elastic body 4 is displaced upward in the figure, the main fluid chamber 7a is compressed. Then, as shown by the arrow in FIG.
Liquid flows into the orifice 6, and the diaphragm 5 is displaced upward in the figure. At this time, the volume of the air chamber 8 is displaced to become smaller, and a volume of air corresponding to this displacement is pushed out through the through hole 10 and the ventilation hole 9. Further, when the main fluid chamber 7a attempts to return to its original state from the compressed state, fluid flows out from the auxiliary fluid chamber 7b to the orifice 6. In this case, the ventilation hole 9 and the through hole 1
Air enters the air chamber 8 through 0.

In this manner, the transmission of engine vibrations to the vehicle body is suppressed by the vibration absorption effect of the elastic body 4 and the damping effect when the sealed liquid passes through the orifice 6.

[0011] Devices having a structure similar to the above-mentioned liquid-filled vibration damping device are disclosed in, for example, Japanese Patent Laid-Open No. 1-320343 and Japanese Patent Laid-Open No. 62-261730.

0012

[Problems to be Solved by the Invention] By the way, when the engine vibration becomes large and the vibration of the inner cylinder 1 becomes large, the elastic body 4
The thick portion 21 of the partition plate 13 comes into contact with the partition plate 13. In this case, the stress from the inner cylinder 1 would be concentrated at the contact area between the thick wall portion 21 and the partition plate 13, which could deteriorate the contact area and reduce the vibration absorption effect.

[0013]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides an inner tube, an outer tube, an elastic body and a diaphragm disposed between the inner tube and the outer tube, and an elastic body. a partition plate that separates the recess formed in the main fluid chamber into a main fluid chamber and a sub-fluid chamber located closer to the diaphragm than the main fluid chamber; In a liquid-filled vibration damping device that includes an orifice that communicates with Two thick parts are formed that are approximately symmetrical about the longitudinal direction of the inner cylinder as a center line, and these two
It is characterized by forming a recessed part located between the two thick parts and extending in the longitudinal direction of the inner cylinder.

[0014]

[Operation] When the vibration of the inner cylinder becomes large and the elastic body comes into contact with the partition plate, two thick portions formed near the center of the recess of the elastic body both come into contact with the partition plate. Therefore, the stress from the inner cylinder is distributed over the two thick parts and is not concentrated in one part.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a sectional view taken along line A--A in FIG. In FIGS. 1 and 2, members equivalent to those shown in FIGS. 4 and 5 are denoted by the same reference numerals, and their explanations will be omitted.

In FIGS. 1 and 2, 20a and 2
0b is a thick portion formed near the center of the recess 12, and the thick portions 20a and 20b are formed approximately symmetrically with respect to the longitudinal direction of the inner cylinder 1. Further, 19 is a recessed portion formed between the thick portions 20a and 20b, and this recessed portion 19 extends in the longitudinal direction of the inner cylinder 1.

5a and 5b are diaphragms, and in a normal state, these diaphragms 5a and 5b are
The openings 11a and 11b respectively bend inward of the outer cylinder 3 in a hemispherical shape. And diaphragm 5a
The diaphragm at the intermediate portion between and 5b is in contact with the inner circumferential surface of a bridge portion 16 of the outer cylinder 3, which will be described later. An air chamber 8 is formed by the outer peripheral surfaces of these diaphragms 5a and 5b and the inner peripheral surface of the bracket 2.

Further, as shown in FIG. 3, a groove 17 is formed on the outer peripheral surface of the bridge portion 16 between the openings 11a and 11b formed in the outer cylinder 3 to connect the openings 11a and 11b. has been done. An air passage 18 is formed by this groove 17 and the inner peripheral surface of the bracket 2.

In the above configuration, when the inner cylinder 1 vibrates due to engine vibration and the elastic body 4 is displaced upward in the figure,
The main fluid chamber 7a is compressed. Then, liquid flows into the sub-fluid chamber 7b from the orifice 6.

Then, the diaphragms 5a and 5b are
The outer cylinder 3 is displaced in the radial direction, and the volume of the air chamber 8 is reduced. At this time, an amount of air corresponding to the change in volume of the air chamber 8 is pushed out from the air chamber 8 through the air passage 18 and the ventilation hole 9. In this case, if diaphragms 5a and 5
Even if the amount of displacement of b becomes large, the diaphragm 5a
and 5b contact the inner circumferential surface of the bracket 2, but do not contact the corners of the openings 11a and 11b. On the other hand, in the liquid-filled vibration isolators shown in FIGS. 4 and 5, if the diaphragm 5 is largely displaced, the diaphragm 5 may come into contact with the corner of the through hole 10 and deteriorate. There is. Therefore, in the example of FIG. 1, the orifices 5a and 5b are prevented from being deteriorated by the corners such as the openings 11a and 11b.

When the main fluid chamber 7a attempts to return to its original state from the compressed state, fluid flows out from the auxiliary fluid chamber 7b to the orifice 6. In this case, air enters the air chamber 8 via the vent hole 9 and the air passage 18.

Now, the engine vibration has become large and the inner cylinder 1
Suppose that the vibration becomes large and the elastic body 4 comes into contact with the partition plate 22. In this case, the thick parts 20a and 20b of the elastic body 4
both come into contact with the partition plate 22. therefore,
The stress from the inner cylinder 1 is dispersed in the thick parts 20a and 20b and is not concentrated in one part.

The partition plate 22 is inclined from the fluid inlet of the sub-fluid chamber 7b to the vicinity of the center of the sub-fluid chamber 7b. In other words, the fluid inlet of the sub-fluid chamber 7b does not decrease rapidly compared to the flow path diameter of the orifice 6, but gradually decreases. Therefore, the sealed fluid can smoothly flow into the auxiliary fluid chamber 7b from the orifice 6, and the damping effect of the sealed liquid is improved.

According to one embodiment of the present invention described above,
Thick parts 20a and 20b are formed near the center of the recess 12 of the elastic body 4, and these thick parts 20a and 20
A recessed portion 19 is formed between the inner cylinder 1 and the partition plate 22.
When the partition plate 22 is largely displaced in the direction of
a and 20b are configured to be in contact with each other. Therefore, the stress from the inner cylinder 1 is
The elastic body 4
Deterioration of the contact portion with the partition plate 22 can be suppressed, and a decrease in the vibration absorption effect can be suppressed.

In the above-described embodiment, the partition plate 22 is connected from the fluid inlet of the sub-fluid chamber 7b to the sub-fluid chamber 7b.
Although the partition plate was tilted to near the center of the
The present invention can be applied even to a shape like the example shown in FIG.

[0026]

As described above, according to the present invention, there is provided an inner tube, an outer tube, an elastic body and a diaphragm disposed between the inner tube and the outer tube, and a recess formed in the elastic body. a partition plate that separates the main fluid chamber into a main fluid chamber and a sub-fluid chamber located closer to the diaphragm than the main fluid chamber; an orifice formed along the inner circumference of the outer cylinder and communicating the main fluid chamber and the sub-fluid chamber; In a liquid-filled vibration damping device that is provided on the outer circumferential side of a diaphragm and has an auxiliary fluid chamber and an air chamber adjacent to each other via the diaphragm, a recess is formed in the elastic body near the center of the concave portion in the longitudinal direction of the inner cylinder. It forms two thick parts that are approximately symmetrical about the center line, and also forms a recessed part that is located between these two thick parts and extends in the longitudinal direction of the inner cylinder, and the inner cylinder is connected to the partition plate. When there is a large displacement in the direction of , the two thick parts come into contact with the partition plate, so the stress from the inner cylinder is
It is dispersed in two thick parts and is not concentrated in one part. Therefore, deterioration of the contact portion of the elastic body with the partition plate is suppressed, and a decrease in the vibration absorption effect of the elastic body can be suppressed.

[Brief explanation of drawings]

FIG. 1 is a sectional view of one embodiment of the invention.

FIG. 2 is a sectional view taken along line A-A in FIG. 1;

FIG. 3 is a perspective view of an outer cylinder of one embodiment.

FIG. 4 is a sectional view of an example of a conventional device.

FIG. 5 is a sectional view taken along line BB in FIG. 4;

FIG. 6 is a perspective view of a conventional outer cylinder.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Inner cylinder, 3... Outer cylinder, 4... Elastic body, 5a, 5b... Diaphragm, 6... Orifice, 7a... Main fluid chamber, 7b... Subfluid chamber, 8... Air chamber, 12... Recessed part, 19... Recessed part , 20
a, 20b...thick part.

Claims (1)

[Claims] Claim 1: An inner cylinder, an outer cylinder, an elastic body and a diaphragm disposed between the inner cylinder and the outer cylinder, and a recess formed in the elastic body that is arranged between a main fluid chamber and a main fluid chamber. A partition plate that separates the auxiliary fluid chamber located on the diaphragm side, an orifice formed along the inner circumference of the outer cylinder that communicates the main fluid chamber and the auxiliary fluid chamber, and an auxiliary fluid chamber provided on the outer periphery of the diaphragm. In a liquid-filled vibration isolator equipped with an air chamber and an air chamber adjacent to each other via a diaphragm, a concave portion 2, which is approximately symmetrical about the longitudinal direction of the inner cylinder as a center line, is located near the center of a concave portion formed in an elastic body. At the same time as forming two thick parts,
1. A liquid-filled vibration isolator characterized in that a recessed part is formed between two thick parts and extends in the longitudinal direction of an inner cylinder.