JPH0366947A - Liquid sealed vibration isolator - Google Patents

Abstract

PURPOSE:To greatly prolong the service life of the subject liquid sealed vibration isolator and effectively prevent deterioration of the performance of this liquid sealed vibration isolator by manufacturing a vibration isolating rubber body to constitute a main liquid chamber and a rubber film to constitute a sub liquid chamber as separate bodies and by using a rubber material which is superior in ozone proof and gas permeation proof. CONSTITUTION:At the time of inputting vibration, the relative position of an inner cylinder 2 and an outer cylinder 1 changes and in concert with it, a main liquid chamber A deforms and sealed liquid flows to a sub liquid chamber B through a throttle passage F and causes the damping of vibration. At this time, a rubber film 4 forming a chamber wall of the sub liquid chamber B deforms in concert with the incoming and outgoing flow of sealed liquid, but as it is superior in ozone proof, it does not cause deterioration, and as it is also superior in gas permeation proof, it effectively prevents mixture of air in the liquid inside the sub liquid chamber B. Consequently, the vibration isolation performance of the liquid sealed vibration isolator can be well maintained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a liquid-filled vibration isolator, and particularly to a cylindrical liquid-filled vibration isolator in which a liquid chamber is formed within a vibration-isolating rubber body disposed between an inner and outer cylinder. Regarding.

[Prior Art] Due to its compact shape, cylindrical liquid-filled vibration isolators are often used in vehicle engine mounts, etc., and a typical structure is as shown in Japanese Patent Application Laid-Open No. 63-214531, for example. A main liquid chamber is formed in the vibration-proof rubber body that occupies most of the space inside the outer cylinder, and a sub-liquid chamber is formed by a thin sealing rubber ring in the space penetrating the outer cylinder in the axial direction. Vibration damping is achieved by flowing a sealing liquid through the connecting flow channels.

Usually, the rubber film is integrally formed by extending a part of the vibration-proof rubber body in the form of a film.

[Problems to be Solved by the Invention] However, the characteristics required for the vibration isolating rubber body that constitutes the chamber wall of the main liquid chamber and performs a vibration isolating effect, and the rubber membrane that stores the fluid flowing out from the main liquid chamber are insufficient. In the conventional structure described above, since natural rubber (NR) material is used with priority given to the characteristics of the vibration-proof rubber body, the durability of the rubber film is difficult, and
There was a risk that air would penetrate the rubber membrane and get mixed into the sealing liquid, deteriorating the vibration damping properties.

The present invention has been made to solve this problem, and an object of the present invention is to provide a liquid-filled vibration isolator in which the vibration isolating rubber body constituting the main liquid chamber and the rubber film constituting the auxiliary liquid chamber can each exhibit optimal characteristics. shall be.

[Means for Solving the Problems] To explain the present invention in detail, an inner cylinder 2 is disposed within an outer cylinder 1 so that the axial direction thereof coincides with the outer cylinder 1, and a gap between the inner cylinder 2 and the outer cylinder 1 is A vibration isolating rubber body 3 is bonded and arranged leaving a space penetrating in the axial direction to form a main liquid chamber A with this as a chamber wall within the vibration isolating rubber body 3, and in the space, A freely deformable rubber membrane 4 made of a rubber material with excellent gas permeability and ozone resistance is stretched separately from the vibration-proof rubber body 3, and the sub-liquid uses the rubber membrane 4 as a chamber wall. A chamber B is formed, and the main liquid chamber A and the sub-liquid chamber B are communicated with each other through a throttle channel F.

[Function] In the liquid-filled vibration isolator with the above configuration, when vibration is input, the relative position of the inner cylinder and the outer cylinder changes, the main liquid chamber is deformed accordingly, and the sealing liquid flows into the secondary liquid through the throttle channel. It flows into the chamber and causes vibration damping. The rubber membrane that makes up the chamber wall of the sub-liquid chamber deforms as the sealing liquid enters and exits, but it does not deteriorate due to its excellent ozone resistance, and it also has excellent gas permeation resistance. Also, air is effectively prevented from being mixed into the liquid in the sub-liquid chamber. In this way, the vibration isolation performance of the device is maintained well.

[First Embodiment] In FIGS. 1 and 2, a vibration-proof rubber body 3 is fitted and fixed in the upper half of an outer cylinder 1. That is, the vibration isolating rubber body 3 is joined to the inner circumferential surface of the interring 6, and the interring 6 is press-fitted into the inner circumference of the outer cylinder 1 with the widthwise end edge of the outer circumference touching the inner circumference of the outer cylinder 1. A recess 31 with both side walls left is formed in the vibration-proof rubber body 3 to constitute a main liquid chamber A.
The main liquid chamber A faces an opening provided in the interring 6. The vibration-proof rubber body 3 is made of a natural rubber material having appropriate elasticity and wear resistance.

The interring 6 is recessed inward at the center of its outer periphery, and the amount of recess is larger in the lower half. An orifice ring 5 is disposed in this concave portion in contact with the inner periphery of the outer cylinder 1, and the orifice ring 5 opens at a portion corresponding to the lower half concave portion of the interring 6, and covers this opening with a thin wall. A rubber membrane 4 is stretched.

That is, as shown in FIG. 3, a protrusion 51 is formed in the center of the opening circumferential surface of the orifice ring 5, and this protrusion 51
The concave grooves on the outer periphery of the rubber membrane 4 are aligned with and joined. A perspective view of the orifice ring 5 provided with the rubber membrane 4 is shown in FIG. A protruding strip 41 for sealing is formed on the upper and lower surfaces of the rubber membrane 4 near the outer periphery (see Fig. 5), which means that the outer periphery of the rubber membrane 4 is inserted between the outer cylinder 1 and the interring 6. It is deformed by soaking in the state to ensure perfect sealing performance.A sub-liquid chamber B is formed between the rubber film 4 and the interring 6.

The rubber film 4 is made of a rubber material with excellent gas permeability and ozone resistance, such as isobutylene-isoprene copolymer rubber (II
R>, chlorinated isobutylene/isoprene copolymer rubber (C
I-I IR), chloroprene rubber (CR), ethylene-propylene-diene copolymer rubber (EPDM), etc.

A groove is formed on the outer periphery of the upper half of the orifice ring 5, the negative end of which communicates with the main liquid chamber A, and which is folded back midway and the other end communicates with the auxiliary liquid chamber B, forming a throttle flow path F. .

An inner cylinder 2 is embedded through the lower end of the vibration isolating rubber body 3, and a stirring plate 7 is protruded from the center upper surface of the inner cylinder 2.
It is located within the main liquid chamber A. The stirring plate 7 is a generally fan-shaped metal plate with a constant thickness, the width of which is the width of the base wheel, and the width gradually increases toward the tip, and the surface is covered with a rubber layer. A stopper rubber 32 having a constant thickness is bonded to the end face, and is in contact with the outer peripheral surface of the recessed portion of the interring 6.

In the liquid-filled vibration isolator having the above structure, the outer cylinder 1 is fitted and fixed into, for example, a cylindrical bracket of an engine, and the inner cylinder 2 is fixed to a vehicle frame by a mounting bolt inserted therein.

While supporting the engine, the inner cylinder 2 receives its static load.
moves upward and is located approximately at the center of the outer cylinder l. The position of the stirring plate 7 at this time is shown by the chain line in FIG. As shown in the figure, a substantially triangular space with <, 1 > N 1 is formed.

In a liquid-filled vibration isolator having such a structure, when large vibrations are input, the inner cylinder 2 is largely displaced relative to the outer cylinder l, the main liquid chamber A is deformed, and the sealing fluid passes through the throttle flow path F and enters the secondary Liquid chamber B
distributed in Thus, a large vibration damping force is generated and input vibrations are quickly reduced. Rubber membrane 4 of sub-liquid chamber B
Although it repeatedly deforms as the sealing fluid enters and exits, its excellent ozone resistance reduces deterioration over time and maintains good operation.

Further, since the rubber film 14 has excellent gas permeation resistance, there is no risk of air entering the sealing liquid and deteriorating the damping characteristics of the device.

When a high frequency micro-vibration is input, the stirring plate 7 vibrates together with the inner cylinder 2, and the sealing liquid flows back and forth at high speed between the tip of the stirring plate 7 and the small gap 11 between the outer cylinder 1, causing liquid resonance, which causes effective Vibration is absorbed.

Furthermore, since the stirring plate 7 has no wing-shaped extending portion, there is no risk of fatigue failure of the wing portion due to bending vibration, and the durability is excellent! ! It is something that was given. Further, it is also possible to mold the entire body from a rubber body, and in this case, manufacturing becomes easier.

[Second Embodiment] As shown in FIG. 7, the rubber membrane 4 may be molded separately from the orifice ring 5. In this case, the rubber membrane 4 is formed between the edge of the orifice ring opening 5a and the outer cylinder Pinch the outer edge (
Figure 8). That is, a chevron-shaped protrusion 42 is formed on the outer peripheral edge of the rubber membrane 4, and this protrusion 42 is fitted and fixed into a groove formed at the edge of the orifice ring opening 5a. A sealing protrusion 43 (FIG. 9) is formed on the surface of the rubber film 4 opposite to the surface on which the protrusion 42 is formed, and the protrusion 43 is deformed by being soaked during clamping to maintain sealing properties. .

[Third Embodiment] The structure for sandwiching the rubber film 4 may be the structure shown in FIG. 10. That is, in the figure, an insert ring 44 is embedded in the outer peripheral edge of the rubber membrane 4, and sealing protrusions 45 and 46 are formed on the upper and lower surfaces of this outer peripheral edge (No. 11).
figure). The outer peripheral edge of the rubber is sandwiched between the stepped recess 52 on the edge of the orifice ring opening 5a and the outer cylinder (2).

[Fourth Embodiment] In each of the above embodiments, a single large opening 5a was formed in the orifice ring 5 and the rubber film 4 was covered therewith.
As shown in the figure and FIG. 13, a pair of small openings 5b,
5c, and rubber membranes 4A and 4B are placed in each opening 5b and 5c.
If these rubber films 4 are bonded and covered respectively,
The durability of A and 4B can be further improved.

[Effects of the Invention] As described above, in the liquid-filled vibration isolator of the present invention, the vibration isolating rubber body constituting the main liquid chamber and the rubber membrane constituting the auxiliary liquid chamber are manufactured separately, and the above-mentioned rubber By using a rubber material with excellent ozone resistance and gas permeation resistance as the membrane, the life of the device can be greatly extended, and deterioration of device performance can also be effectively prevented.

[Brief explanation of drawings]

1 to 6 show a first embodiment of the present invention.
Figure 2 is a cross-sectional view of the entire device, Figure 2 is a vertical sectional view of the entire device, Figure 3 is a sectional view of the main part, Figure 4 is a perspective view of the main part, and Figure 5 is an enlarged sectional view of the rubber membrane joint. , FIG. 6 is a schematic diagram of the space formed by the stirring plate, FIGS. 7 to 9 show a second embodiment of the present invention, FIG. 7 is an exploded perspective view of the main part, and FIG. 8 is a rubber clamp. Figure 9 is an enlarged cross-sectional view of the outer peripheral part of the rubber membrane.
0 and 11 show the third embodiment of the present invention, and the first embodiment
Figure 0 is an enlarged cross-sectional view of the rubber clamping part, Figure I1 is a cross-sectional view of the outer peripheral part of the rubber membrane, Figures 12 and 13 show the fourth embodiment of the present invention, and Figure 12 is a cross-sectional view of the entire device. The top view and FIG. 13 are partial perspective views of the orifice ring. Engineering... Outer cylinder 2... Inner cylinder 3... Vibration-proof rubber bodies 4.4A, 4B... Rubber membrane 5... Orifice rings 5a, 5b, 5 c... Opening 6... Interring 7...Stirring plate A...Main liquid chamber B...Sub-liquid chamber F...Restriction channel Fig. 5 322 Fig. 1 Fig. 2 Fig. 7 Fig. 9 Fig. 10 Fig. 11 Figure 6 Figure 12 Figure 13

Claims (1)

[Claims] An inner cylinder is disposed within the outer cylinder so that the axial direction thereof coincides with the inner cylinder, and a vibration isolating rubber body is bonded and arranged between the inner cylinder and the outer cylinder, leaving a space penetrating in the axial direction, A main liquid chamber is formed in the vibration-isolating rubber body with this as a chamber wall, and the space is made of a rubber material with excellent gas permeability and ozone resistance, separate from the vibration-isolating rubber body. By installing a freely deformable rubber membrane,
A liquid-filled vibration isolator characterized in that a sub-liquid chamber is formed with the rubber membrane as a chamber wall, and the main liquid chamber and the sub-liquid chamber are communicated through a constricted flow path.