JPS585549A - Vibration preventer containing sealed liquid - Google Patents

Abstract

PURPOSE:To effectively absorb vibrations in a vibration preventer applicable to the engine supporting part of a vehicle, by installing a vibration damping mechanism of low frequency and high amplitude, and a vibration absorbing mechanism of high frequency and low amplitude as an integral structure on the partition plate to partition a fluid chamber. CONSTITUTION:For a high frequency and low amplitude vibration a displacement of a rubber elastic wall 95 is small, so that liquid is flowed through a penetrating hole 8, by which liquid pressure changes in a first fluid chamber 1 can be absorbed. The penetrating hole 8 is formed widely enough not to cause the damping action. On another hand, in case where low frequency and high amplitude is involved, the rubber elastic wall 95 is largely displaced by the increase in the liquid pressure changes in the first fluid chamber 1, a void 10 which is formed into a fluid path and the opening of the penetrating hole 8 are narrowed. Thus, also the viscous resistance is increased, and large damping action is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a first fluid chamber and a second fluid chamber partitioned by a partition plate. This invention relates to an improvement in reducing vibrations of a supported body supported in a chamber.

This type of liquid-filled vibration isolator is applied to engine support parts of vehicles, etc., and generally uses a first fluid with a chamber wall made of a thick rubber elastic body that supports a supported object such as an engine. A second fluid chamber whose chamber wall is a rubber elastic body between which floor the bellows is located, and a partition plate which partitions both fluid chambers and has a throttle hole in the center as basic elements. When the supported body vibrates, the volume of the first fluid chamber changes due to the deformation of the chamber wall, a pressure difference is created between both fluid chambers, and the enclosed liquid flows through the aperture hole, causing vibration due to the viscous resistance at that time. A damping effect occurs.

By the way, when this type of vibration isolator is applied to the engine support part of a vehicle, the sealed liquid flows through the throttle hole to strongly attenuate low-frequency, high-amplitude vibrations. On the other hand, it is desirable that vibrations can be absorbed without the damping effect caused by flow through the throttle holes.

In view of these requirements, a means to construct a diaphragm by making a part of the chamber wall of the first fluid chamber thin is to absorb changes in fluid pressure due to high frequency and low amplitude vibrations of the first fluid chamber by deforming the diaphragm. It is being

The present invention incorporates a mechanism that effectively absorbs fluid pressure changes in the first fluid chamber at high frequency and low amplitude, and a mechanism that effectively exerts a damping effect due to liquid flow between both fluid chambers at low frequency and high amplitude, in an integrated structure. The present invention provides a liquid-filled vibration isolator in which this structure is formed on a partition plate.

Hereinafter, details of the present invention will be explained with reference to illustrated embodiments.

In FIG. 1, numeral 1 is a first fluid chamber, numeral 2 is a second fluid chamber, and these are partitioned by a partition plate 3, and both fluid chambers 1.
2 is filled with liquid.

The chamber wall of the first fluid chamber 1 is constituted by a conical thick rubber elastic plate 4 and an engine support member 5 embedded in the center thereof.

The lower outer periphery of the rubber elastic thick plate 4 is joined to the inner diameter surface of the device support member 6. The chamber wall of the second fluid chamber 2 is constituted by a bellows 7 made of a rubber elastic material. The partition plate 3, the outer circumferential portion of the bellows 7, and the inner thick wall portion of the device support member 6 are integrally connected in a fluid-tight manner by bolts. The device is supported on the vehicle body by a flange portion 7 on the outer diameter side of the support member 6.

The partition plate 3 is provided with a rectangular through hole 8 at a position deviated to one side from the center thereof. In this device, the eight through-holes have a larger area than the throttle holes provided in the partition plate, and the sealed liquid can freely flow over the through-holes 8 with almost no viscous resistance.

As shown in FIGS. 1 to 4, a member 9 having a gate-shaped cross section and a predetermined length is installed in the center of the partition plate 3 on the side facing the first fluid chamber 1. As shown in FIGS. A tunnel-shaped gap 10 is formed between this member 9 and the partition plate 3, with one end open and the other end closed.

The gap 10 and the through hole 8 communicate with each other, and together constitute a fluid passage between the first and second fluid chambers 1.2. Opposing side wall portions 91 and 92 of the member 9, opening 9
3 and the closing wall portion 94 are made of hard synthetic resin, and most of the upper surface portion is made of a highly flexible rubber elastic wall 95.

In the vibration isolator configured as described above, when engine vibration acts on the first fluid chamber 1, the volume of the first fluid chamber 1 changes due to deformation of the thick plate 4, causing a change in hydraulic pressure.

As a result, the rubber elastic wall 95 acts as a diaphragm. When the amplitude of the vibration becomes large and the change in hydraulic pressure becomes large, the rubber elastic wall 95 comes into contact with the partition plate 3 as shown in FIGS. 5 and 6.

By the way, in the case of high frequency and low amplitude vibration, the rubber elastic wall 95
Due to the displacement, the liquid flows through the through hole 8, whereby changes in the liquid pressure in the first fluid chamber 1 are absorbed. In this case, the displacement of the rubber elastic wall 95 is small, and the fluid passage 8 is formed sufficiently wide, so the liquid flows freely and there is almost no viscous resistance, so there is no damping effect. , in the case of low frequency and high amplitude, as shown in FIGS. 5 and 6, the rubber elastic wall 95 is largely displaced due to an increase in the fluid pressure change in the first fluid chamber 1, and the gap 10 serving as a fluid passage and the transparent The opening of hole 8 becomes narrower. Due to this increase in fluid pressure change and the narrowing of the 10° gap 8, the liquid flows strongly through the fluid passage, and the viscous resistance also increases, resulting in a large damping effect.

As described above, the device of the present invention can absorb high-frequency, low-amplitude vibrations, and can effectively damp low-frequency, high-amplitude vibrations. In particular, since the fluid passage becomes narrower as the amplitude increases, an excellent effect is exhibited in that the damping effect can be increased as the amplitude increases.

7 to 10 show another embodiment, in which a plurality of circular through holes 8 are formed in the partition plate 3, and four holes integrated by an annular portion 96 are formed on the upper surface of the partition plate 3. Legs 97 &
, 9'7b, 97o.

A rubber elastic wall 95 is formed in the annular part 96.The sealed liquid is the first one, the liquid in the body chamber 1 (Fig. 1) Leg 97 due to pressure change
a, 97b, 970, 97 (from gap 1 to gap 10, and further through hole 8, flowing between both fluid chambers 1.2. In this case as well, as in the previous embodiment, the high frequency and low amplitude vibrations is absorbed by freely flowing through the through hole 8, and a damping effect is effectively exerted against high frequency and low amplitude vibrations by narrowing the through hole 8 by displacement of the rubber elastic wall 95.

In this way, the present invention integrates a low-frequency, high-amplitude vibration damping mechanism and a high-frequency, low-amplitude vibration absorption mechanism and houses them inside the device. Since the rubber is present in the sealed liquid, there is no deterioration of the rubber due to ozone, which also contributes to improving the durability and reliability of the device.

[Brief explanation of the drawing]

Figures 1 to 5 show the first embodiment.
The figure is a longitudinal cross-sectional view of the vibration isolator, Figure 2 is a cross-sectional view taken along the line --- in Figure 1, Figure 3 is a cross-sectional view taken along the line ■-■ in Figure 2, and Figure 4 is a cross-sectional view taken in Figure 3. I'/-IV line sectional views, FIGS. 5 and 6 are 81 shown in FIGS. 3 and 4, respectively.
(Figures 7 to 10 are diagrams showing the operating state of the
Fig. 7 is a plan view of the sealed liquid circulation section, Fig. 8 is a sectional view taken along the line ■-■ in Fig. 7, and Fig. 9 shows the state of the members shown in Fig. 8 during operation. The figure shown in Figure 10 is X in Figure 7.
- FIG. 1...First fluid chamber 2...Second fluid chamber 3...Partition plate 8.10...Fluid passage 95...・Rubber elastic wall-8- Fig. 4 Fig. 6 Fig. 3 Fig. 5 Fig. 1 (J, i Fig. 7 3 Fig. 8 304- Fig. 9 V Fig. 10

Claims (1)

[Claims] A first fluid chamber that supports a supported body, a second fluid chamber that is coupled to the first fluid chamber, a partition plate that partitions both fluid chambers, and a partition that allows sealed liquid to flow between both fluid chambers. In a liquid-filled vibration isolator having a through hole provided in a plate, a rubber elastic wall forming a fluid passage communicating with the through hole is provided between the surface of the partition plate on the first fluid chamber side and the surface thereof. A liquid-filled vibration isolating device characterized in that the cross-sectional area of the fluid passage is changed by iJ by deforming a rubber elastic wall in response to a change in fluid pressure in the first fluid chamber.