JPS5999133A - Liquid-sealed vibration-isolating device - Google Patents

Abstract

PURPOSE:To prevent giving of vibration damping through release of a flow passage within a high frequency vibrating area and to give vibration damping through limitation of the flow passage in a low frequency vibration area, by installing a valve member, having a variable flow passage area, to a flow passage through which two fluid chambers are intercommunicated. CONSTITUTION:During low frequency high amplitude, with an electromagnet 8 excited, a valve member 7 is moved upward. This causes the upper end of the valve member 7 to be moved to a level above a through-hole 63 in a pipe 6 to form a narrow throttle part 72 between the valve member and the pipe 6. Thus, fluid flows between first and second fluid chambers A and B through a throttle part 72, and gives vibration damping resulting from meeting with resistance. Meanwhile, during high frequency low amplitude, the electromagnet 8 stops being excited. This causes the valve member 7 to be lowered through the energizing force of a coil spring 9 to open the through-hole 63, which results in intercommunication of the first and second fluid chambers A and B through the through-holes 63 and 62 without meeting with resistance. This enables the spring constant of a device to be maintained at a low value.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid-filled vibration isolator suitable for a vehicle engine mount or the like.

Conventional liquid-filled anti-vibration bag +tFi, a first fluid chamber having a chamber wall made of a thick rubber elastic material wall, and a second fluid chamber having a chamber wall made of a thin rubber elastic material wall with high deformability; The basic elements include a partition plate that partitions both fluid chambers and a throttle hole formed in the partition plate.The fixing member holds the chamber wall of the first fluid chamber, and the supported object is It has a mounting groove structure that supports it. Then, as the chamber wall of the first fluid chamber deforms due to the vibration of the supported body, a fluid pressure difference is generated between both fluid chambers.
The sealed liquid flows through the aperture hole, and the flow resistance at that time acts to damp vibrations.

By the way, in this liquid-filled vibration isolator, when the frequency is high and the amplitude is high, the spring constant of the device is large and the damping force is increased to perform the damping action, and at the time of the high frequency and low amplitude, the spring jt number is small and no damping force is applied. It is required to absorb vibrations and reduce the transmission of vibrations to the vehicle body.

However, it is extremely difficult to satisfy this contradictory requirement with a thick rubber elastic wall.In the meantime, as a means to solve q, a thin film part was formed on a part of the chamber wall of the 19th fluid chamber. A method has been proposed in which the change in fluid pressure in the first fluid chamber due to high-frequency, low-amplitude vibrations is absorbed by deformation of the thin film, but there is a problem in that it is difficult to appropriately set the area and elasticity of the thin film. Fell.

Therefore, it is an object of the present invention to provide a liquid-filled vibration isolator that satisfies both of the above requirements without providing such a thin film portion.

That is, in the present invention, the first fluid chamber is made of a non-deformable material such as metal, and is fixed to a wall of a thick rubber elastic body that supports a supported body, and is wrapped in a deformable material. A second fluid chamber having a chamber wall made of a thin rubber elastic body is communicated with the first fluid chamber through a flow path fixed to a fixed member, and a valve member is provided in the flow path to generate high-frequency vibrations. The feature is that the flow passages are spaced apart in the region, and the flow passage area is narrowed in the low frequency vibration region.

However, according to the device of the present invention, the vibration of the supported body can be applied to a thick rubber elastic body! f! The first fluid chamber is deformed and displaced, but since the flow path is constricted at low frequency and high amplitude, a large fluid pressure change occurs in the first fluid chamber, and the sealed liquid flows through the constricted flow path. , which provides a damping effect. on the other hand,
At high frequency and low amplitude, the flow path is open and the restrictor 9 does not exist, so both fluid chambers become substantially a single fluid chamber, and changes in the sealed fluid pressure are absorbed by deformation of the rubber elastic wall of the M wall.

The present invention will be explained below with reference to illustrated embodiments.

A cylindrical side plate 3 is provided on the outer periphery of the conical thick rubber elastic wall 1.
are joined. A flange portion 31 extending outward is formed at the lower end of the side plate 3, and a bolt is inserted into a hole 32 provided in the seventh rung portion 31 to fix and support the hook W on a double body (not shown). .

A through hole is formed in the axial center of the 11-wall rubber elastic wall 1, and a metal cylindrical casing 2 is joined into the through hole. There are 4 walls shaped at the top of 2 casings,
A bolt 21 is integrally formed to protrude from this, and the engine (not shown) is directly or indirectly supported by the bolt 21.

A container-shaped bottom plate 4 is provided at the lower end opening of the side plate 3 so as to cover it, and the outer peripheral edge of the bottom plate 4 and the seven rungs 31 of the side plate 3 are connected with bolts.

A vibro is coaxially inserted into the casing 2 through its lower opening. This vibro has a pipe support plate 61 formed in a seven-lung shape at the lower end, and its outer periphery is clamped to a fastening portion between the side plate 3 and the bottom plate 4. A plurality of through holes 62 are provided in the pipe support plate 61, and a number of through holes 63 are provided in the outer periphery of the vibro.

On the other hand, a sliding member 10 made of resin is provided on the outer periphery of the upper end of the vibro, and comes into sliding contact with the casing 2.

A rod-shaped valve member 7 having a pointed end is attached to the vibro from below.
is inserted. The valve member 7 is slidably attached to the center of the bottom plate 4 and extends downward, and has a 7 rung portion 7 at its lower end.
1 is formed.

The outer periphery of a thin rubber elastic wall 5 is clamped to the joint between the side plate 3 and the bottom plate 4 so as to curve around 610 pipe support plates. This rubber elastic wall 5 is generally dish-shaped with an L in the center.
A cylindrical portion is formed that rises in the direction, and this cylindrical portion is joined and fixed to the shaft portion of the valve member 7 which has been closed.

A round magnet 8 and a coil spring 9 are arranged around the valve member 7 which projects downward from the bottom plate 5. coil spring 9
urges the valve member 7 in the direction F, and when the magnet 8 is excited, the lower flange 71 of the valve member 7 made of a magnetic material is attracted and the valve member 7 moves upward. The figure shows the state moved upward.

Therefore, inside the device there is a thick-walled rubber elastic body 1 and a casing 2.
, a liquid-filled hermetic chamber 111 surrounded by the side plate 3 and the thin rubber elastic body 5 is formed, and this space communicates with a vibro and is partitioned by a valve member 7 into a first fluid chamber A and a second fluid chamber A.
Driftwood Room B will be constructed by 4tq.

Next, I will explain the operation of the device.
At time 1'ii, the magnet 8 is energized to move the valve member 7 upward. As a result, the upper portion of the valve member 7 moves in the -L direction from the through hole 63 of the vibro, and a small constricted portion 7z is formed between the valve member 7 and the vibro. When the supported body moves up and down due to vibration, the casing 2 also moves upward due to the accompanying deformation of the thick rubber elastic body 1, and the height of the first fluid chamber A changes. Therefore, the sealed liquid flows through the constriction part 72 by J]u
The fluid then flows between @1 and the second fluid chambers A and E, and is subjected to a large flow resistance at the accommodation portion 72, so that a vibration f<summer effect is exerted.

Next, when high frequency and low vibration 11@, i4F, (it3 stop the excitation of the stone 8, d2. This causes the valve member 7 coil spring 9
The upper end surface of the valve member 7 moves below the through hole 63 of the vibro, so that the first and second fluid chambers A
, B communicate through the vibro and its through hole 63.

Since these vibro, through holes 63, pipe support plate 610 and through holes 62 are formed sufficiently wide, almost no flow resistance occurs when the volume changes during the discharge amplitude, and the first
The second fluid chambers A and B can be regarded as a single fluid chamber. Therefore, changes in hydraulic pressure caused by vibrations are absorbed by the deformation of the thin rubber elastic body 5, and the spring constant of the device C can be maintained.

According to the present invention, there is no constriction between the first and second fluid chambers in the high frequency vibration range, so changes in fluid pressure can be absorbed by the chamber wall of the second fluid chamber. Furthermore, since the first fluid chamber is constructed of a casing that does not deform, a change in fluid pressure proportional to vibration in the vertical direction can be obtained, resulting in a large internal pressure and a large damping effect. Furthermore, since the control of the diaphragm can be electrically controlled, it is possible to appropriately determine the critical frequencies of the low frequency range that produces a vibration damping effect and the high frequency range that does not produce a vibration damping effect.

[Brief explanation of drawings]

The figure is a half-sectional view showing one practical example of the present invention. A...First fluid chamber B...Second fluid chamber 1...Original rubber elastic wall 2... Casing 5...I exclusive meat rubber/rhinoceros body wall 6...Pipe (flow path) 7...Valve member ８・・・・・・νhi magnet

Claims (2)

[Claims] (1) A thick rubber elastic body wall that is supported by a fixed member and supports the supported body, and a non-deformable portion that is used as a chamber wall and is displaced together with the thick rubber elastic body due to the vibration of the supported body. 1st
a second fluid chamber having a chamber wall made of a thin rubber elastic body and communicating with the first fluid chamber via a channel fixed to a fixed member; A valve member having a variable flow passage area; and a valve control means that controls the operation of the valve member to open the communication portion in a high frequency vibration range and limit the flow passage area of the communication portion in a low frequency vibration range. A liquid-filled vibration isolator characterized by comprising: (2) A metal stub-shaped casing with one end opening into the second fluid chamber is provided in the thick rubber elastic body to form a first fluid chamber in the casing, and the flow path is connected to the casing opening. The liquid-filled vibration isolator according to claim 1jJ1, wherein one opening end is inserted in relative contact with each other.