JPH0968255A - Liquid sealing type bush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid sealing type bush which permits its metal mold to be commonly used when a separately specified liquid sealing type bush different in the resonance characteristics of a second orifice for high frequency vibration is manufactured, can facilitate its manufacture, and concurrently is profitable costwise. SOLUTION: A second orifice 11 is provided with a second orifice forming hole 2b provided for an inner side mounting part 1 so that liquid chamber 7 and 8 are communicated with each other, a cylindrical case 22 inserted into the second orifice forming hole 2b, and with a diaphragm 13 provided in the inside of the case 12 in such a way that it blocks the inside. And the effective length L of the second orifice 11 is so designed as to be altered by changing the fixed position of the case 12 in the second orifice forming hole 2b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-filled bush used as an anti-vibration device or anti-vibration support device in an automobile or the like. The liquid-filled bush according to the present invention is frequently used as an engine mount for automobiles.

[0002]

2. Description of the Related Art As shown in FIG. 2, a liquid-filled bush has conventionally been provided with an orifice 53 for communicating a first liquid chamber 51 and a second liquid chamber 52 with each other in order to damp low-frequency vibrations. In addition to the provision of the orifice 5
3 shows only the openings for the respective liquid chambers 51 and 52), and a second orifice 54 provided with a diaphragm 55 in order to absorb and suppress high-frequency vibration (see Japanese Patent Laid-Open No. 6-257641). ).

However, in this prior art, the diaphragm 55 has an inner mounting portion 56 and an outer mounting portion 5.
7 is integrally molded with the elastic body 58 made of a rubber-like elastic material, which is connected to 7, and is vulcanized together with the elastic body 58 by using a mold (not shown) so as to obtain a final product shape from the beginning. In addition, after molding, the second orifice 5
The effective length of 4 cannot be changed. Therefore, if the effective length of the second orifice 54 is changed and the resonance characteristic (resonance frequency) of the second orifice 54 is changed to manufacture a liquid-filled bush of another specification (specification), the other portion will be changed. Even if there is no change, the mold has to be recreated from the beginning, and this causes a lot of labor and time for manufacturing, and there is a problem that it is disadvantageous in terms of cost.

[0004]

SUMMARY OF THE INVENTION In view of the above points, the present invention shares a mold when manufacturing a liquid-filled bush of another specification having different resonance characteristics of the second orifice for high frequency vibration ( The purpose of the present invention is to provide a liquid-filled bush that can be used as it is), is easy to manufacture, and is advantageous in terms of cost.

[0005]

In order to achieve the above object, in the liquid-filled type bush of the present invention, the outer mounting portion is connected to the outer peripheral side of the inner mounting portion via an elastic body made of a rubber-like elastic material. Then, a plurality of liquid chambers partitioned by the elastic body are communicated with each other through an orifice, a working fluid is sealed in the liquid chambers, and the inner mounting portion blocks the communication of the liquid chambers with a diaphragm. In a liquid-filled bush having two orifices, the second orifice is inserted in the second orifice forming hole and the second orifice forming hole provided in the inner mounting portion so as to communicate the liquid chambers with each other. A cylindrical case that is attached to the case and a diaphragm that is provided inside the case so as to block the inside thereof are provided, and the fixing position of the case in the second orifice forming hole can be changed. And that the effective length of said second orifice is changed by.

[0006]

In the liquid-filled type bush of the present invention having the above-mentioned structure, the fixed position of the case in the second orifice forming hole is changed when the case is inserted into the second orifice forming hole during manufacturing. It is possible to change the effective length of the second orifice for high frequency vibration, and the resonance characteristic of the second orifice is changed accordingly. Therefore, in the case of manufacturing a liquid-filled bush having different specifications in which the resonance characteristics of the second orifice are different, it is possible to share (use as it is) a mold for vulcanizing and molding the elastic body.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An elastic body made of a rubber-like elastic material for connecting an inner mounting portion and an outer mounting portion is vulcanized and bonded to constituent parts of both mounting portions simultaneously with vulcanization molding. Further, the diaphragm made of a rubber-like elastic material forming the second orifice is vulcanized and bonded to the case at the same time as the vulcanization and molding. Therefore, when manufacturing the liquid-filled bush of the present invention, two sets of molds are required. If there are two sets of molds, the fixing position of the case in the second orifice forming hole should be changed. It is possible to change the effective length of the second orifice steplessly.

[0008]

Embodiments of the present invention will now be described with reference to the drawings.

As shown in FIG. 1, the orifice ring 4 is provided on the outer peripheral side of the inner (inner peripheral side) mounting portion 1 provided with the inner cylinder 2.
And an outer (outer peripheral side) mounting portion 3 having an outer cylinder 5 is arranged, and the inner cylinder 2 and the orifice ring 4 are arranged in a substantially V-shaped elastic body 6 made of a rubber-like elastic material. They are connected to each other through legs (also referred to as rubber legs) 6a, an outer cylinder 5 is fitted on the outer peripheral side of the orifice ring 4, and is vertically divided by the pair of legs 6a on the inner peripheral side of the outer cylinder 5. Further, a first liquid chamber 7 and a second liquid chamber 8 are provided, and a working liquid (also referred to as an internal sealing liquid) 9 such as a viscous fluid is enclosed in both liquid chambers 7, 8. The orifice ring 4 is provided with a pair of component parts (also referred to as connecting parts) having an arcuate cross-section indicated by reference numerals 4a and 4a, but is provided with annular parts (not shown) at both axial end parts not shown. An orifice 10 is provided in one of the annular portions so that the liquid chambers 7 and 8 communicate with each other (the drawing shows only the openings of the orifice 10 for the liquid chambers 7 and 8). The elastic body 6 includes a pair of legs 6a and a covering portion 6b that covers the surface of the inner cylinder 2, and further forms a wall portion (both rubber wall portions) that constitutes axial end walls of both liquid chambers 7 and 8. (Not shown) and the like.

A convex portion 2a is integrally formed on the left side surface of the inner cylinder 2 as viewed in the figure.
A second orifice 11 is provided in a, and the second orifice 11 is provided in the convex portion 2a so as to communicate the two liquid chambers 7 and 8 with each other (also referred to as a second orifice hole). 2b, a case 12 made of a rigid material such as a metal and having a cylindrical shape, which is inserted into the second orifice forming hole 2b from above in the figure, and vulcanized and adhered to the inside of the case 12 to block the inside. And a diaphragm (also referred to as a film portion or a rubber film portion) 13 made of a rubber-like elastic material having a bellows shape, and the second orifice forming hole 2b.
The effective length L of the second orifice 11 is changed depending on the fixed position (insertion depth) of the case 12 in FIG. The inner wall of the second orifice forming hole 2b is provided with a stepped stopper portion 2c that defines the limit of the insertion depth of the case 12.

The liquid-filled bush having the above structure is
For example, one of the inner mounting portion 1 and the outer mounting portion 3 is mounted on the vehicle body side of the automobile and the other mounting portion is mounted on the engine side to support the vibration isolation of the engine. When the vibration is input, the vibration is effectively damped by the elasticity provided in the leg portion 6a of the elastic body 6 and the flow resistance or the liquid column resonance of the hydraulic fluid 9 flowing through the orifice 10. Further, when a high-frequency, small-amplitude vibration is input to the bush, the hydraulic fluid 9 moves in and out of the second orifice 11 according to the input direction and resonates, so that the absolute spring constant of the bush is suppressed to a low level. As a result, this vibration can be effectively absorbed and suppressed.

When manufacturing the bush, the diaphragm 13 is vulcanized in advance to a predetermined position when manufacturing a liquid-filled bush of another specification in which the resonance characteristic of the second orifice 11 for high frequency vibration is different. When the adhered case 12 is inserted into the second orifice forming hole 2b, the effective position of the second orifice 11 is changed by changing the fixing position of the case 12 in the second orifice forming hole 2b.
Can be changed, and the resonance characteristics of the second orifice 11 can be changed accordingly. Therefore, even in the case of manufacturing a liquid-filled type bush having different specifications in which the resonance characteristics of the second orifice 11 are different, it becomes possible to share (use as it is) the mold for vulcanizing and molding the elastic body 6, and another Since it is not necessary to manufacture a new mold, it is possible to save labor and time, and it is possible to manufacture a liquid-filled bush that is also advantageous in terms of cost. Since the fixed position of the case 12 in the second orifice forming hole 2b is changed steplessly and the effective length L of the second orifice 11 is also changed steplessly, the resonance characteristic of the second orifice 11 is changed. Changes can also be made steplessly.

[0013]

The present invention has the following effects.

That is, in the liquid-filled type bush of the present invention having the above-mentioned structure, when the case is inserted into the second orifice forming hole during manufacturing, the fixing position of the case in the second orifice forming hole is changed. By doing so, it is possible to change the effective length of the second orifice for high frequency vibration, and it is possible to change the resonance characteristic of the second orifice accordingly. Therefore, even when manufacturing a liquid-filled bush having different specifications with different resonance characteristics of the second orifice, the mold for vulcanizing and molding the elastic body can be shared (used as it is). Since it is not necessary to newly manufacture the liquid-filled bush, it is possible to save labor and time, and it is possible to manufacture the liquid-filled bush which is also advantageous in cost. Further, since the above change is made steplessly, there is an effect that the resonance characteristic of the second orifice can be finely adjusted.

[Brief description of drawings]

FIG. 1 is a sectional view of a liquid-filled bush according to an embodiment of the present invention.

FIG. 2 is a sectional view of a liquid-filled bush according to a conventional example.

[Explanation of symbols]

 1 Inner Mounting Part 2 Inner Cylinder 2a Convex Part 2b Second Orifice Forming Hole 2c Stopper Part 3 Outer Mounting Part 4 Orifice Ring 4a Constituent Part with Circular Arc Section 5 Outer Cylinder 6 Elastic Body 6a Leg 6b Cover Part 7 First Liquid chamber 8 Second liquid chamber 9 Hydraulic fluid 10 Orifice 11 Second orifice 12 Case 13 Diaphragm L Effective length

Claims (1)

[Claims] 1. An outer mounting portion (3) is connected to an outer peripheral side of an inner mounting portion (1) through an elastic body (6) made of a rubber-like elastic material, and is partitioned by the elastic body (6). A plurality of liquid chambers (7) and (8) are communicated with each other through an orifice (10), the working liquid (9) is sealed in the liquid chambers (7) and (8), and the inner mounting portion (1) is attached. In a liquid-filled bush provided with a second orifice (11) in which communication between the liquid chambers (7) and (8) is blocked by a diaphragm (13), the second orifice (11) has the inner mounting portion. (1)
A second orifice forming hole (2b) provided so that the liquid chambers (7) and (8) communicate with each other, and a cylindrical case (1) inserted into the second orifice forming hole (2b).
2) and a diaphragm (13) provided inside the case (12) so as to block the inside,
A liquid-filled bush characterized in that the effective length (L) of the second orifice (11) is changed by changing the fixing position of the case (12) in the second orifice forming hole (2b). .