JPS60184740A - Elastic bush - Google Patents

Abstract

PURPOSE:To permit a vehicle to comfortably run all over by providing a fluid chamber and an air chamber in a bush whereby assuring a satisfactory damping characteristic over low frequency and large amplitude regions and an excellent vibration transmission characteristic over high frequency and micro-amplitude region. CONSTITUTION:An inner cylinder 1 is fixedly mounted on an inside elastic member 3, while an outer cylinder 2 fixedly mounted on an outside elastic member 4. Fluid chambers 5 are provided on the inner elastic member 3 at symmetrical positions thereof perpendicularly to an axis thereof. The two opposing fluid chambers 5 are communicated with each other through a communication hole 7 formed with a ring material 6 fitted to the internal cylinder 1 from the outside thereof. An air chamber 8 is provided in the outside elastic member 4, and the chamber 8 is formed by the external cylinder 2 and disposed adjoining to the fluid chamber 5 via a bellows 9. Any high frequency and micro-amplitude vibration can be, if produced, absorbed by the air chamber 8, while vibration of low frequency and large amplitude can be prevented from transmitted due to damping produced as a fluid passes through the communication hole 7.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an elastic bushing used in a suspension for a vehicle such as an automobile, and was developed for the purpose of improving a composite elastic bushing in which an incompressible fluid is enclosed in an elastic body.

One general suspension push is an elastic sleeve made of rubber material between an inner tube fitting into which a predetermined support shaft is inserted for suspension of 41 cars, and an outer tube fitting arranged concentrically with the inner tube fitting. However, in order to change the vibration damping characteristics depending on the load direction, techniques such as providing a hollow in the rubber elastic body or sealing in an incompressible fluid are used6. A composite bushing has been developed with a structure in which holes for sealing incompressible fluid are provided at symmetrical positions in the direction perpendicular to the axis of the body, the holes are communicated through orifices, and each hole and orifice is filled with fluid. As a result, fairly good vibration damping characteristics have been obtained. However, even if such a composite bushing is used, if the damping is increased to eliminate the jittery feeling that occurs when driving over a protrusion, etc., the inertial resistance of the internal liquid will gradually increase as the I++ frequency region approaches. Eventually, fluid will no longer pass through the orifice, and even if an elastic body is interposed between the inner and outer cylinders, it will appear to be a rigid body between them, significantly deteriorating the vibration transmission characteristics in the high frequency range. Disadvantages 6 The elastic bushing according to the present invention has a structure that satisfies both the damping characteristics in the low frequency, large amplitude region and the vibration transmission characteristics in the high frequency and small amplitude region, and eliminates the jittery feeling, while at the same time The objective is to provide a high-performance elastic bushing that improves vibration transmission characteristics in all areas and allows comfortable driving in all areas. The second feature of its structure is that a fluid chamber and an air chamber are provided via bellows at almost symmetrical positions in the direction perpendicular to the axis of the inner and outer elastic bodies, and a communication hole is provided between the opposing fluid chambers. . In addition to the above-mentioned characteristics, the product of the present invention also has a stopper function to prevent excessive deformation under excessive load, and has a structure that takes into consideration the durability of the elastic bushing.

The present invention will be described in detail below with reference to illustrative drawings.

Fig. 1 is a longitudinal cross-sectional view of the elastic bushing, and Fig. 2 is a longitudinal cross-sectional view of the elastic bushing.
It is a sectional view taken along the line AA in the figure. FIG. 3 is a longitudinal sectional view showing another embodiment. FIG. 4 is a sectional view taken along line BB in FIG. 3.

The elastic bushing of the present invention shown in these figures is particularly useful as a trailing link bushing, and is useful as a trailing link bushing.
) is fixed to the inner elastic body (3), and the outer cylinder (2) is fixed to the outer elastic body (4). In the elastic bushing illustrated in FIGS. 1 and 2, the inner elastic body (3)
A fluid chamber (5) is provided at a symmetrical position in the axis-perpendicular direction. These two opposing fluid chambers (5) (5) are connected to the inner cylinder (1).
The communicating hole (
7). The ring material (6) is not limited to a perfect circle, but may be an oval or other deformed ring, and can be fixed to the inner cylinder (1) by caulking or welding. The communication hole (7) is connected to the introduction part (12) (1
2), it is in communication with the fluid chambers (5) (5). The fluid chamber (5) is filled with a fluid containing an appropriate mixture of silicone oil, glycols, water, grease, etc. according to the desired vibration characteristics. The outer elastic body (4) has an air chamber (
8) is provided, and this air chamber (8) is connected to the outer cylinder (2).
is formed by. Air chamber (8) and fluid chamber (5)
There is a bellows (9) between. Inner elastic body (3
) and the bellows (9), the bellows is integrated with the outer elastic body (4) and equipped with an outer clamping ring (10), and is further fitted with an inner ring (10) to the inner elastic body (3). ring(
11), and a bellows (9) integrated with the tightening outer ring (10) and an outer elastic body (4) are press-fitted or press-fitted and bonded thereto. At this time, if the tightening outer ring (10) is caulked toward the inner ring, the sealing performance is further improved.

The objects shown in FIGS. 3 and 4 can also achieve the object of the present invention in the same manner as described above. That is, in this example, conversely, the outer elastic body (4) is provided with the fluid chamber (5), and the inner elastic body (3) is provided with the air chamber (8). The opposing fluid chambers (5) (5) are in communication with each other through a communication hole (7) provided in a groove shape in the outer cylinder (2). Air chamber (8
) is formed around one circle in this example, but it may be formed partially.

In these elastic bushings, the volume ratio of the air chamber to the fluid chamber and the diameter of the communication hole (orifice) are changed depending on the vibration damping characteristics required for the vehicle type, etc. Further, in the examples shown in FIGS. 3 and 4, the performance can be changed by providing the communicating holes only on one side instead of all around the circumference, or by making one side have a large diameter and the other one a small diameter. Furthermore, as shown by the two-dot chain line in FIG. 4, the vibration damping characteristics can be changed by controlling a structure in which a valve element such as a solenoid valve (13) is moved in and out of the communication hole.

As described above, by providing the air chamber and the fluid chamber by sandwiching the bellows between the elastic bodies, the following effects can be obtained. That is, the fluid in the fluid chamber (5) is pushed into the air chamber (8) through one bellows (9), and when further displacement is applied, the fluid in the fluid chamber (5) is forced into the air chamber (8) through the bellows (9). 7) and is pushed into the fluid chamber on the opposite side, causing attenuation due to the resistance of the communication hole.

To explain this effect in detail, when low frequency and large amplitude occur, such as when driving over a bump, the internal fluid passes through the communication hole and attenuation occurs, but in a small amplitude high frequency region that causes road noise, The inertial resistance of the fluid is large, and even if the fluid does not pass through the communication hole, the herous (9) spreads toward the air chamber side, and by performing volume compensation, the high frequency transmission characteristics can be greatly improved. As described above, the present invention provides an elastic bushing with high performance in all areas required for elastic bushings used particularly in suspensions.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of the elastic bushing, and Fig. 2 is a longitudinal cross-sectional view of the elastic bushing.
It is a sectional view taken along the line AA in the figure. FIG. 3 is a longitudinal sectional view showing another embodiment. FIG. 4 is a plan view of part 14118-B in FIG. 3. (1) Inner cylinder (2) Outer cylinder (3) Inner elastic body (4) Outer elastic body (5) Fluid chamber (6) Ring material (7) Communication hole (8) Air chamber (9) Bellows (1O) Tighten Outer ring (11) Inner ring (12) Introduction Applicant Kurashiki Kako Co., Ltd. Agent Patent attorney Morihiro Third Department Figure 1 Figure 2 Item 3 Item 3 Fourth circle

Claims (1)

[Claims] In an elastic bushing having a damping effect in the direction perpendicular to the axis through the elastic body 4 between the inside and outside i and 6, a fluid chamber and an air chamber are provided via bellows at substantially symmetrical positions in the direction perpendicular to the axis of the elastic body, and An elastic bushing characterized by having a communication hole between fluid chambers.