JPH0788866B2 - Anti-vibration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a vibration damping device used for an engine mount or the like for an automobile.

[Background technology]

BACKGROUND ART In engine mounts, car mounts, body mounts, and the like for automobiles, a vibration isolation device provided with a liquid chamber is used to absorb vibration.

As an example, as shown in Japanese Patent Laid-Open No. 52-131072, this vibration isolator has a liquid chamber divided into small liquid chambers through an orifice, and when vibrating, liquid in one liquid chamber passes through the orifice and the other The resistance that reaches the liquid chamber absorbs vibration.

However, in such a vibration isolator, when high frequency vibration is applied, the orifice is clogged, so that the dynamic spring constant increases. Further, since the orifice is provided on the outer periphery of the pipe penetrating the central portion, the length of the orifice is limited and a large attenuation cannot be obtained.

The present invention has been made in consideration of the above facts, and an object thereof is to provide a vibration isolator that can appropriately absorb high frequency vibrations and can provide sufficient damping by providing a long orifice.

[Outline and Action of Invention]

The present invention relates to an inner cylinder attached to one of the vibration generating portion and the vibration support portion, an outer cylinder attached to the other, an elastic thick film connecting one axial end between the inner and outer cylinders, and a space between the inner and outer cylinders. An elastic thin film that connects the other axial end of the elastic thick film to form a liquid chamber, and a partition wall that spans between the inner and outer cylinders and divides the liquid chamber into a small liquid chamber. The partition wall has an inner cylinder and a slidable inner ring, an outer ring attached to the outer cylinder, and an elastic body interposed between the inner and outer rings, and the outer ring has the small liquid chamber. It is characterized by the formation of an orifice that communicates with each other.

Therefore, in the vibration isolator according to the present invention, when the vibration from the engine, the cabin or the like acts, the vibration is absorbed by the resistance when the fluid in one small liquid chamber reaches the other through the orifice. Since the orifice is formed on the outer ring of the partition wall, its axial length can be lengthened and a large damping effect can be obtained.

Also, when the vibration becomes high frequency and small amplitude, the orifice becomes clogged, but in this case, the small liquid chamber on the side where the elastic thin film is provided suppresses the rise of the liquid chamber due to the elastic deformation of the elastic thin film. Vibration is properly absorbed without an increase in the dynamic spring constant.

Example of Invention

1 and 2 show a vibration isolation device 10 according to an embodiment of the present invention. In this vibration isolator 10, the lower end of the auxiliary outer cylinder 14 is fixed to the upper end of the outer cylinder 12, and the upper end of the auxiliary outer cylinder 14 is a flange portion 16 protruding in the radial direction and a flange plate 18 is fixed. Has been done. A circular hole 22 is formed in the flange portion 16 and the flange plate 18 as shown in detail in FIG. 2 and serves as a mounting portion to a vehicle body (not shown).

An elastic thick film 24 is vulcanized and adhered to the inner peripheral portion of the auxiliary outer cylinder 14, and this elastic thick film 24 is also vulcanized and attached to the outer circumference of a connecting cylinder 28 that is arranged coaxially with the outer cylinder 12. The connecting cylinder 28 is fixed to the outer periphery of the inner cylinder 30, and the inner cylinder 30 is arranged coaxially with the outer cylinder 12. Therefore, the elastic thick film 24 is composed of the outer cylinder 12 and the inner cylinder.
It will be handed over to 30.

A top plate 32 is fixed to the upper end of the inner cylinder 30, and a vehicle cabin (not shown) mounted on the top plate 32 is supported by a mounting bolt that is fixed through the inner cylinder 30.

The lower end of the inner cylinder 30 projects below the lower end of the outer cylinder 12,
A stopper plate 34 is fixed to the tip portion. An elastic thin film 36 is inserted and fixed directly above the stopper plate 34. A tightening ring 38 is provided inside the elastic thin film 36 to firmly attach the elastic thin film 36. The outer circumference of the elastic thin film 36 is vulcanized and attached to the inner circumference of the connecting cylinder 42. This connecting cylinder 42 is inserted into the inner circumference of the outer cylinder 12 from below the outer cylinder 12, and has a flange portion bent in the radial direction at the lower end.
42A is fixed by a caulking portion 12A provided on the lower end portion of the outer cylinder 12.

As a result, the outer cylinder 12, the auxiliary outer cylinder 14, the inner cylinder 30, the elastic thick film 2
4, the elastic thin film 36 and the connecting cylinder 42 form a liquid chamber 44, and liquid such as water or oil is sealed in the liquid chamber 44.

The liquid chamber 44 is partitioned by a partition wall 46 into an upper small liquid chamber 44A and a lower small liquid chamber 44B. The partition wall 46 has an inner ring 48 that is slidable on the outer circumference of the inner cylinder 30 in the axial direction of the inner cylinder 30. It is preferable that a gap of about 0.2 to 0.3 mm is provided between the inner ring 48 and the outer circumference of the inner cylinder 30. An elastic body 50 is vulcanized and adhered to the outer periphery of the inner ring 48 together with the outer ring 52.

The outer ring 52 has an elastic thick film at one end and the outer circumference in the axial direction.
It is supported by an extension 24A from a part of 24, and the lower end is a connecting tube 4
The upper end of 2 is pressed against the extension 24A. Further, as shown in FIG. 3, the outer ring 52 has a groove formed over about half the circumference thereof, and an orifice 54 is formed between the outer ring 52 and the extension 24A.

One end in the axial direction of this orifice 54 is communicated with the upper small liquid chamber 44A by a notch 56, and the other end is communicated with the lower small liquid chamber 44B by a notch 58. Therefore, the upper small liquid chamber 44A and the lower small liquid chamber 44B are communicated with each other through the orifice 54, and the orifice has a long axial length. In the case of further extending the axial length of this orifice 54, it may be rotated a plurality of times around the axis of the outer ring 52, and a spiral orifice can be set according to the required length.

When manufacturing this vibration isolator 10, an elastic thick film 24 is vulcanized and bonded between the auxiliary outer cylinder 14 attached to the outer cylinder 12 and the connecting cylinder 28 attached to the inner cylinder 30 in advance. Assembled parts are manufactured, immersed in liquid, the partition wall 46 is inserted into the inner cylinder 30, the elastic thin film 36 is further inserted into the inner cylinder 30, and the outer peripheral part is fixed by the caulking part 12A of the connecting cylinder 42. To do. The elastic thin film 36
The fastening ring 38 and the stopper plate 34 prevent the inner peripheral portion thereof from coming off.

Next, the operation of this embodiment will be described.

The auxiliary outer cylinder 14 is fixed to a vehicle body (not shown) through the circular hole 22,
A casing (not shown) is mounted and fixed to the inner cylinder 30. The load of this cabin is mainly supported by the elastic thick film 24.

The vibration generated in the cabin when the vehicle is traveling is transmitted to the elastic thick film 24, and is absorbed by the internal resistance of the elastic thick film 24.

If the vibration of the cabin is low frequency, the upper small liquid chamber
The vibration applied to 44A acts as a force to transfer the liquid in the upper small liquid chamber 44A to the lower small liquid chamber 44B through the orifice 54, but the vibration is attenuated by viscous resistance when this liquid passes through the orifice 54. It In particular, since the orifice 54 has a long axial length, sufficient damping characteristics can be obtained.

At the time of this vibration, the inner cylinder 30 and the inner ring 48 relatively move in the axial direction, so that the expansion of one of the upper small liquid chamber 44A and the lower small liquid chamber 44B acts as a contraction of the other, and in the orifice 54 portion. The damping becomes more effective. Even when vibration in a direction different from the axial direction of the inner cylinder 30 is applied, the inner cylinder 30 and the inner ring 48 can move relative to each other, so that there is no hindrance to the vibration absorbing action.

When the vibration has a high frequency and small amplitude, the orifice 54 becomes clogged. In this case, the pressure of the liquid chamber 44 rises and the dynamic spring constant increases, but in this embodiment, the elastic thin film 36 is thin and easily elastically deformed, so that the lower small liquid chamber 44B can be easily expanded. As a result, the pressure rise of the liquid chamber 44 as a whole is suppressed to 1/2, and the rise of the dynamic spring is halved.

The inner ring 48 in the above embodiment is not limited to metal such as iron and aluminum, but synthetic resin can be used.

〔The invention's effect〕

As described above, the present invention provides an inner cylinder attached to one of the vibration generating portion and the vibration support portion, an outer cylinder attached to the other, an elastic thick film connecting one axial end between the inner and outer cylinders, and these. An elastic thin film that connects the other axial ends between the inner and outer cylinders to form a liquid chamber with the elastic thick film; and a partition wall that spans between the inner and outer cylinders and divides the liquid chamber into small liquid chambers. , And the partition wall has an inner cylinder and a slidable inner ring,
An outer ring attached to the outer cylinder and an elastic body interposed between these inner and outer rings are provided, and since the outer ring is formed with an orifice which communicates the small liquid chambers with each other, With a long orifice, great damping is obtained, and the pressure rise during high frequency vibration is suppressed, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a vibration isolator according to the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a perspective view showing an outer ring. 10 …… Anti-vibration device, 12 …… Outer cylinder, 24 …… Elastic thick film, 30 …… Inner cylinder, 36 …… Elastic thin film, 44 …… Liquid chamber, 44A …… Upper liquid chamber, 44B …… Lower Small liquid chamber, 46 ... Partition wall, 48 ... Inner ring, 50 ... Elastic body, 52 ... Outer ring, 54 ... Orifice.

Claims (1)

[Claims] 1. An inner cylinder attached to one of the vibration generator and the vibration support, an outer cylinder attached to the other, an elastic thick film connecting one axial end between the inner and outer cylinders, and these inner and outer cylinders. An elastic thin film that connects the other axial ends between the elastic thick film and the elastic thin film, and a partition wall that spans between the inner and outer cylinders and divides the liquid chamber into small liquid chambers. The partition wall includes an inner cylinder and a slidable inner ring, an outer ring attached to the outer cylinder, and an elastic body interposed between the inner and outer rings, and the outer ring has the small liquid chamber. An anti-vibration device, characterized in that an orifice is formed which communicates with each other.