JPH02190638A - Liquid seal type elastic bush - Google Patents

Abstract

PURPOSE:To cut off and attenuate engine vibration for high-speed running by installing a recessed pot on the inside of an outer tube on the extension of a stopper and thrusting the stopper into this recessed pot at a preset small gap. CONSTITUTION:A stopper 11 which moves outward from an inner tube 1 to an outer tube 2 along the vibration direction is provided on the inner tube 1 in a liquid chamber 4. A recessed pot 12 is installed on the inside of the outer tube 2 on the extension of the stopper 11. The stopper 11 is thrust into the recessed pot 12 at a preset small gap. When the recessed pot 12 and a mass body 14 are adequately arranged, the rise of the dynamic spring constant can be suppressed against the frequency up to about 350Hz at the maximum. Engine vibration can be cut off or attenuated for high-speed running.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid-sealed elastic bushing suitable for use as an engine mount of an automobile.

[Conventional technology]

Conventionally, in the case of bush-type vibration isolating rubber, a liquid chamber was separated inside the rubber elastic body and communicated with an orifice structure, and a liquid was sealed inside, in order to improve the damping performance during low-frequency vibrations. Liquid-sealed elastic bushings are seen (for example, Patent No. 88
5820), but the disadvantages of this type of elastic bushing are: 50! The dynamic spring constant increases all at once in the primary frequency range below 1z, impairing vibration isolation.

Therefore, the inventors constructed a movable valve in an orifice structure that communicates between liquid chambers, and by absorbing vibration energy by the behavior of this movable valve (Japanese Patent Application No. 145710/1982)
, succeeded in suppressing the increase in dynamic spring constant to the second-order frequency range of about 15011z.

[Problem to be solved by the invention]

However, in recent high-speed driving, vibration isolation, that is, suppression of the increase in dynamic spring constant, is required to extend to a higher frequency range.

This invention was devised in order to solve these problems, and its purpose is to provide a certain configuration in the liquid chamber, so that the 250112 or 350H
This is due to the development of a liquid-sealed elastic bushing that suppresses the increase in the spring constant up to the 2nd 2nd 4th order frequency range, which is even higher than before.

[Means to solve the problem]

In other words, this invention.

A liquid-sealing liquid chamber is separated by a side wall and a partition wall in the rubber elastic body molded between the inner cylinder and the outer cylinder.

A movable valve having an orifice structure that communicates between the two separated liquid chambers is installed, and a stopper is provided in the inner cylinder in the liquid chamber to make sound from the inner cylinder to the outer cylinder along the vibration direction. In the liquid seal type elastic bushing, a recessed bot is installed inside the outer cylinder on an extension of the stopper, and the stopper is inserted into the recessed bot with a predetermined small gap. .

The elastic bushing having this structure is a liquid seal type elastic bushing in which a mass body is added by interposing an elastic body on the outer periphery of the recessed bond.

, was provided.

[Effect]

By taking the above measures, the vibrations in the first and second frequency ranges emitted from the vibrating body are absorbed by the liquid movement in the orifice structure and the behavior of the movable valve. The constant does not increase, while vibrations in the higher tertiary frequency range are absorbed by the movement of fluid between the stopper and the recessed bot, and vibrations in the even higher 4th frequency range are absorbed by the recessed bot. The dynamic spring constant does not increase, at least in this frequency range, because it is absorbed by the vibration of the mass body added to it.

〔Example〕

Examples of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view of a liquid-sealed elastic bushing according to this invention, FIG. 2 is a vertical cross-sectional view, and FIG. 3 is a cross-sectional view showing another embodiment.

This liquid-sealing type elastic bushing consists of an inner cylinder l and an outer cylinder 2 made of gold EaJ.
(However, those used for engine mounts are set eccentrically in the opposite load direction, and those used for roll insulators are set concentrically.)
A sleeve-shaped rubber elastic body 3 is integrally molded between the two 1.2, and a suitable incompressible liquid is sealed inside this rubber elastic body 3 to separate two liquid chambers 4. It is. That is, if the inner cylinder 1 is provided with a side wall 5 in a direction perpendicular to its axis and a partition wall 6 in a horizontal direction to create a space inside the inner cylinder 1, and inserted into the outer cylinder 1 in liquid, this space will be filled. The part becomes the liquid chamber 4, and a liquid can be sealed inside. By the way, in this case 5, if it is an eccentric type, make it on the eccentric side in the eccentric (vibration) direction, and if it is a concentric type, make the part (11175) on both sides of the vibration direction curved inward. In addition, near the outer peripheral end of the rubber elastic body 3, a core bar 7 with a window-shaped notch in the liquid chamber 4 is inserted to increase strength, and a rubber elastic body is also inserted outside the core bar 7. A slight layer of layer 3 is provided, and several protrusions (
(not shown) improves sealing performance during liquid sealing.

Next, the two liquid chambers 4 are communicated with each other by a movable valve 9 having an orifice structure 8. That is, a communication hole 10 is formed at a suitable location in the partition wall 6, and a movable valve 9 having a cross-sectional shape having a considerable gap in both the valve body and valve head directions is installed in the communication hole 10.
A through hole connecting both liquid chambers 4 is provided in this flexible valve train 9, and this is used as an orifice structure 8. Further, a stopper 11 is attached to the outer periphery of the inner cylinder 1 in the liquid chamber 4, which comes into contact with the outer cylinder 2 when an excessive displacement occurs. Furthermore, on the extension of this stopper 11, a recessed bottom 12 is provided on the inner periphery of the outer cylinder 2, etc., in which a part of the tip of the stopper 11 projects into the upper opening hole with a predetermined small gap. Although the stopper 11 is provided in the liquid chamber 4 on both the biased side and the biased side, the recessed bottom 12 is generally provided in the fluid chamber 4 on the biased side. However, if you want to further improve the vibration isolation performance described in 1&.

The recessed bots 12 may be provided in both liquid chambers 4, and a heavy mass body 14 may be added to the outer periphery of the recessed bond 12 with an elastic body 13 interposed therebetween as necessary. .

As described above, when the engine is attached to the inner cylinder l side and the chassis is attached to the outer cylinder 2α11 to elastically support the engine, first,
For vibrations in the first frequency range of about 101Hz, vibrations are damped and blocked by liquid movement in the orifice structure 8.For vibrations in the second frequency range of about 150Hz, vibrations are damped and blocked. Vibration energy is absorbed by the behavior of the movable valve 9, and an increase in the dynamic spring constant is suppressed, thereby blocking vibration. Conventionally, if a vibration with a frequency exceeding this second frequency range was input, the spring constant would increase from this point, but here, the above-mentioned recessed positive eye 2 is provided. By appropriately tuning the size of the gap between the concave bot 12 and the stopper 11, the length of the overlapping part, etc., the 250H frequency exceeding the second frequency range can be achieved.
For vibrations up to the second frequency range of about z, the inner cylinder l,
That is, one stroke of the stopper 11 converts the liquid in the recessed bond 12 into energy that moves it in and out of the recessed bond 12, and therefore does not increase the dynamic spring constant. If you add body 14, you can exceed this by 35011
For vibrations in the fourth frequency range of about z, this mass body 1
The energy used to vibrate 3 is consumed, and the dynamic spring constant is not increased in the same way. It should be noted that FIG. 4 shows these configurations and the relationship between the frequency and the increase in dynamic spring constant based on these configurations.

〔Effect of the invention〕

From the above, by appropriately arranging the recessed bond 12 and the mass body 14, it is possible to suppress the increase in the dynamic spring constant for vibration frequencies up to a maximum of 350 I (Z), so that the engine Can block and damp vibration.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a liquid-sealed elastic bushing according to the present invention, FIG. 2 is a vertical cross-sectional view, FIG. 3 is a cross-sectional view showing another embodiment, and FIG. 4 is a diagram showing the frequency and dynamics. It is a graph showing a relationship with a spring constant. (Symbol) l... Inner tube 2... Outer tube 3... Rubber elastic body 4... Liquid chamber 5... Side wall 6... Partition wall 8... Orifice structure 9... Movable valve 11... Stopper 12... Recess Bond 13...Elastic body 14...Mass body Figure 3

Claims (1)

[Claims] [1] A liquid-sealing liquid chamber ( 4), and a movable valve (9) having an orifice structure (8) that communicates the two separated liquid chambers (4) is installed on this partition wall (6). ) in which the inner cylinder (1) is provided with a stopper (11) that extends from the inner cylinder (1) toward the outer cylinder (2) along the vibration direction; 11
) A concave pot (12) inside the outer cylinder (2) on the extension of the outer cylinder (2)
is installed, and the stopper (11) is placed in this concave pot (
12) A liquid-sealed elastic bush that is inserted into the interior with a predetermined small gap. [2] A liquid seal type elastic bushing comprising a mass body (14) with an elastic body (13) interposed on the outer periphery of the recessed pot (12) according to claim [1].