JPH0247615B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluid-filled mount that mainly aims at reducing vibration transmission in a low frequency range.

A base member that is fixed to a fixed member and a mounting member that is connected to a vibration source are connected by a shear type elastic member,
Fluid-filled mounts are known in which a fluid is sealed in an internal fluid chamber.

When such a fluid-filled mount is used as an engine mount, vibrations in the low rotation range of the engine, that is, in the low frequency range, are transmitted to the base member via the elastic member because no liquid pressure with the opposite phase is generated.
In particular, transmission of idling vibrations generates vibration noise in the vehicle interior.

The present invention has been made in view of the above circumstances.
The purpose of this is to reduce vibration transmission mainly in the low frequency range by generating fluid pressure that is in the opposite phase to vibration transmission. An object of the present invention is to provide a fluid-filled mount capable of reducing noise, particularly improving idling vibration noise.

In order to solve the above problems and achieve the object, the present invention connects a mounting member connected to a vibration source and a base member on which the vibration source is mounted with an elastic member, and also connects the mounting member to the mounting member side or the base member side. A fluid-filled mount in which a diaphragm is provided on either one of the diaphragms to form a fluid chamber therein, a partition plate is provided to divide the fluid chamber into two chambers, and a cylindrical communication portion having a large inner diameter is provided in the partition plate. , a movable plate member having a hole having a smaller diameter than the inner diameter of the communicating portion and a larger opening area at both ends of the cylindrical communicating portion, and having a diameter larger than the hole and smaller than the inner diameter of the communicating portion; is housed in the cylindrical communication portion, and the movable plate is floatingly supported at an intermediate position within the cylindrical communication portion by truncated conical helical springs arranged above and below.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a central longitudinal cross-sectional view of a mount to which the present invention is applied, in which a female tapered cylindrical portion 3 is provided at the top of a cylindrical portion 2.
An umbrella-shaped elastic member 5 made of thick rubber is baked onto the inner periphery of the female tapered cylindrical portion 3 of the base member 1, which has an annular clamping portion 4 with a U-shaped cross section at the bottom thereof. The elastic member 5 is baked onto the male tapered surface 8 of the mounting member 6 which has a male tapered surface 8 formed on the outer periphery, and a partition plate 11 and a thin rubber diaphragm are placed in the annular holding portion 4 of the base member 1 in order from the top. Insert 10.

A somewhat large diameter D is provided at the center of the partition plate 11.
A circular hole 12 of 1 is formed, and an inner diameter D larger than the diameter of the circular hole 12 is formed on the partition plate 11 around the circular hole 12.
2 and a low-height cylinder 15 as shown.
The circular hole 12 is installed at the upper end of the cylinder 15.
A circular hole portion 16 having the same diameter D1 is formed.

A thick disk member 21 having an outer diameter D3 that is larger than the diameter D1 of the circular hole 12 and the circular hole portion 16 and sufficiently smaller than the inner diameter D2 of the cylinder 15 is housed in the cylinder 15, This disk member 2
1 and the circular hole portion 16 and the partition plate 11, truncated conical helical springs 23 and 24 are provided, respectively.
is stretched, and the disc member 21 is floatingly supported concentrically in the center of the cylinder 15 and at an intermediate position between the upper and lower sides.

In this way, the main fluid chamber S1 is located above the partition plate 11.
A liquid is sealed in a mount having an auxiliary fluid chamber S2 formed therebelow, the base member 1 is fixed to the vehicle body frame, and the engine is connected to a mounting screw 9 protruding from the mounting member 6.

As described above, the cylinder 15 having a large inner diameter D2 is provided on the partition plate 11, and the circular hole portion 16 and the circular hole 12 having a smaller diameter D1 than the inner diameter D2 are provided at the upper and lower ends of this cylinder 15, and these hole portions 16, 1
The thick disk member 21 having a diameter D3 larger than 2 is floatingly supported and stored at an intermediate position within the cylinder 15 by upper and lower truncated conical spiral springs 23 and 24, so that the following effects are achieved. can.

That is, in a vibrating state in which the disc member 21 does not come into contact with the circular hole portion 16 at the upper and lower ends of the cylinder 15 and the periphery of the circular hole 12, vibration is applied to the mounting member 6, and the elastic member 5 is deformed, causing the main fluid chamber S1 When the fluid pressure inside changes, it flows through the passage 22 formed between the cylinder 15 and the disc member 21 to the sub-fluid chamber S2.
The liquid pressure inside also changes with almost no attenuation,
The diaphragm 10 is deformed. Accordingly, the elastic member 5 and the diaphragm 10 represent the liquid pressure exerted on the disk member 21 in the cylinder 15, and the mass system of the thick disk member 21 floating vertically within the cylinder 15. The vibration transmission generates a liquid pressure with a phase opposite to that of the vibration transmission, and the vibration transmission is canceled by this liquid pressure with a phase opposite to that of the vibration transmission. In other words, due to the offsetting effect, it is possible to reduce vibration transmission at a low frequency commensurate with the mass of the thick disk member 21, and therefore it is possible to achieve a reduction in cabin noise in the low engine speed range. can.

Especially from 450, which is the engine idling range.
By setting the mass of the disc member 21 so that it resonates at a vibration frequency of 990 rpm to 15 to 33 Hz, it is possible to significantly improve idling vibration noise.

On the other hand, the fluid chamber S1 defined by the partition plate 11,
Since the holes 16 and 12 at the upper and lower ends of the cylinder 15, which form the communication section of S2, both have large opening areas, even against high frequency vibration, there is no flow between the upper and lower fluid chambers S1 and S2 through the passage 22. Since the fluid moves freely, the elastic member 5 can sufficiently isolate vibrations.

Incidentally, the movement of the disc member 21 is restricted by the circular hole portion 16 at the upper and lower ends of the cylinder 15 and the circumferential edge of the circular hole 12, and if a larger load is applied, communication between the upper and lower fluid chambers S1 and S2 will be interrupted. This increases the rigidity of the mount.

Therefore, if an orifice 13 is formed in the partition plate 11 around the cylinder 15 as shown in FIG.
It is possible to generate damping against large loads, improving the performance of the mount.

Further, as shown in FIG. 3, the same effect can be obtained by forming an orifice 27 in the center of the disc member 26. In this embodiment, the disc member 26 is formed thicker as shown in the figure. We are trying to increase the mass.

In the above, floating support of each of the movable plates 21 and 26 is performed by the truncated cone-shaped helical springs 23 and 24 disposed above and below, so that the downward movement of the movable plates 21 and 26 is directed toward the lower surface of the movable plates 21 and 26. In addition to being supported by the compressive deformation of the helical spring 24, the upward movement of the movable plates 21 and 26 can be reliably supported by the compressive deformation of the helical spring 23 on the upper surface side. .

And a spiral spring 2 with a truncated conical shape on both the top and bottom.
3 and 24, it is possible to prevent the movable plates 21 and 26 from swinging in the vertical direction, and the movable plates 2
Stable mounting characteristics can be obtained by the smooth vertical movement of 1 and 26.

As described above, according to the present invention, in a fluid-filled mount in which a diaphragm is provided on either the mounting member side or the base member side connected by an elastic member to form a fluid chamber inside, the fluid chamber is divided into two chambers. A hole with a smaller diameter and a larger opening area than the inside of the communication part is formed at both ends of a cylindrical communication part with a large inner diameter provided in the partition plate that defines the partition, and a hole with a larger opening area than the above hole is formed in the cylindrical communication part. A movable plate material with a diameter smaller than the inner diameter of the communication part is housed and is floatingly supported in the middle position by a spring material, so that the movable plate material resonates in the low frequency vibration range and can generate liquid pressure in the opposite phase to vibration transmission. This makes it possible to improve, for example, engine idling vibration and noise.Moreover, since the holes at both ends of the cylindrical communication part have a large opening area, both fluid chambers can be effectively reduced in the high frequency vibration range. The elastic member can absorb the pressure fluctuation between the two and provide sufficient vibration isolation.

As the spring material that floats and supports the movable plate, truncated cone-shaped helical springs arranged above and below are used, so the downward movement of the movable plate is caused by the compressive deformation of the helical spring on the lower side. In addition, the upward movement of the movable plate can be reliably supported by compression deformation of the helical spring on the upper surface side, and the vertical movement of the movable plate can be prevented from swinging. This can be prevented, and stable mounting characteristics can be obtained by smooth vertical movement of the movable plate.

[Brief explanation of the drawing]

FIG. 1 is a central longitudinal sectional view of a mount to which the present invention is applied, and FIGS. 2 and 3 are longitudinal sectional views of main parts showing modified examples, respectively. In the drawings, 1 is a base member, 5 is an elastic member, 6 is a mounting member, 10 is a diaphragm, 11 is a partition plate,
15 is a cylindrical communication part, 12 and 16 are holes,
21 and 26 are movable plate materials, 23 and 24 are spring materials, 1
3 and 27 are orifices, and S1 and S2 are fluid chambers.

Claims (1)

[Claims] 1. A mounting member connected to a vibration source and a base member on which the vibration source is mounted are coupled by an elastic member, and a diaphragm is provided on either the mounting member side or the base member side. In a fluid-filled mount having a fluid chamber formed inside, a partition plate is provided to divide the fluid chamber into two chambers, a cylindrical communication portion having a large inner diameter is provided on the partition plate, and a cylindrical communication portion having a large inner diameter is provided at both ends of the cylindrical communication portion. A hole having a smaller diameter than the inner diameter of the communicating portion and having a larger opening area is formed, and a movable plate member having a larger diameter than the hole and smaller than the inner diameter of the communicating portion is housed in the cylindrical communicating portion. A fluid-filled mount, characterized in that the movable plate member is floatingly supported at an intermediate position within the cylindrical communication portion by a truncated cone-shaped helical spring arranged above and below. 2. The fluid-filled mount according to claim 1, wherein the partition plate or the movable plate member is provided with an orifice.