JPH0228744B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a rubber bush for a vehicle suspension, and more particularly to a hydraulically movable rubber bush for a suspension whose central axis can be moved by pressure input from the outside. It is related to.

Prior Art Conventionally, various types of rubber bushes for suspensions of vehicles such as automobiles have been proposed and actually used, depending on the various required characteristics of the location where they are installed.

For example, in the case of an automobile rear suspension as shown in FIG. 1, left and right rear wheels 2a, 2b
Suspension arms 4a, 4 with attached
b is rotatably supported by a suspension member 6, and the suspension member 6 is attached to the vehicle body via rubber bushes 8a and 8b, which are so-called member mounts. The rubber bushings 8a, 8b have inner cylinders 10a, 10b fixed to the vehicle body and outer cylinders 12a, 12b fixed to the suspension member 6.

By the way, such conventional rear suspensions have a structure in which the same bushings are used to isolate vibrations from the road surface and to support the side force when turning, so it is difficult to avoid vibrations when riding over small bumps on the road surface. In order to isolate the front and back vibrations of the tires, the spring characteristics of the rubber bushings can be softened to reduce vibrations when the suspension member rotates, for example, when the side force F shown in Fig. 1 is applied to the rear wheels when the vehicle is turning left. The toe-out angle (hereinafter referred to as toe angle): α increases, causing a problem of deterioration of running stability at high speeds. On the other hand, in order to reduce the change in this toe angle: α, it is sufficient to make the spring characteristics of the rubber bushes 8a and 8b harder. The characteristics will also become hard, which will reduce the vibration absorption performance when riding over small bumps on the road surface as described above. Therefore, in order to improve running stability when turning,
The spring characteristics of the rubber bushes 8a and 8b are kept soft to better absorb longitudinal vibrations, while the B of the suspension member 6 increases the toe angle: α when inputting the side force F in the left and right direction.
It is desirable to suppress changes in direction (rotation).

For this reason, as a rubber bushing that can keep the toe angle α small as mentioned above,
Japanese Patent Publication No. 224802 discloses a hydraulically movable bushing in which the center axis of the bush can be moved by hydraulic pressure input from the outside.

This hydraulically movable rubber bush has a recess integrally formed in the rubber elastic body interposed between the inner and outer cylindrical metal fittings, and a predetermined pressure fluid is applied from the outside into the recess. By guiding the hydraulic pressure to the rubber elastic body and transmitting it to the inner cylindrical fitting, relative displacement is caused between the inner cylindrical fitting and the outer cylindrical fitting. Because it is a rubber elastic body,
There is a problem in that it is difficult to form a closed recess for applying a predetermined hydraulic pressure, and the structure is complicated. On the other hand, the hydraulic pressure introduced to move the center axis acts directly on the rubber elastic body, which causes extra deformation and fatigue on the rubber elastic body, causing the gap between the outer cylinder fitting and the rubber elastic body to deteriorate. This has inherent problems such as causing peeling and reducing the durability of the rubber.
Furthermore, there was a risk that the rubber elastic body would be deteriorated by the pressure liquid itself supplied from the outside.

Purpose of the Invention The present invention has been made against the background of the above, and its purpose is to provide an external An object of the present invention is to provide a rubber bushing for a vehicle suspension which is easy to manufacture and which minimizes the adverse effects of pressure derived from the air, especially pressure fluid.

Structure of the Invention In order to achieve this object, the present invention includes an inner metal fitting attached to either the vehicle body or the suspension member; and an outer metal fitting attached to the other side of the suspension member, and a rubber elastic body interposed between the inner metal fitting and the outer metal fitting. With a space appearing between them, both metal fittings are elastically held together by the rubber elastic body on both sides of the inner metal fitting in a direction substantially orthogonal to the opposing direction of the space. While connecting the two, an inflatable flexible bag is disposed in each of the spaces, and a pressure supply port is provided that penetrates the wall of the outer metal fitting and opens into the flexible bag, By supplying pressure from an external pressure source through the pressure supply port, the flexible bag is selectively inflated to press the inner metal fitting, and the inner metal fitting is moved relative to the outer metal fitting. It was made so that it could be displaced.

As described above, according to the present invention, the rubber elastic body and the pressurizing member, in other words, the flexible bag constituting the pressurizing chamber, are separated, and the pressurizing chamber is Because it is not integrally formed within the rubber elastic body, the material such as rubber constituting the flexible bag is different from the material of the rubber elastic body, and the pressure medium such as pressure liquid that is introduced is different from the material of the rubber elastic body. Of course, it is now possible to use rubber materials that are not affected by As a result, it is possible to effectively eliminate unnecessary deformation and fatigue on such rubber elastic bodies and flexible bags, and advantageously improve their durability. It was.

Moreover, such a flexible bag can be easily installed and fixed in the space between the inner metal fitting and the outer metal fitting by an appropriate means, so that the intended pressurizing mechanism can be easily installed. Since it can be formed, the rubber bushing can be manufactured with great ease.

A rubber bushing having such a structure is particularly suitable for use in a rear suspension device as a rubber bushing that can effectively isolate longitudinal vibrations of the tire and keep the toe angle of the rear outer wheel small when turning. It is.

EXAMPLES Hereinafter, in order to clarify the present invention more specifically, examples of the present invention will be described in detail based on the drawings.

First, in FIGS. 2 and 3, reference numeral 14 denotes an outer metal fitting having a box shape with upper and lower ends open, in other words, a square tube shape, and two opposing flat plates 16, 16 are connected to each other. The box-shaped shape is formed by riveting to the bent flange portions of the ends of the other pair of flat plates 18, 18 arranged in a direction perpendicular to the flat plates 18, 18. Then, an inner metal fitting 20 having a rectangular cross-sectional outer shape is arranged so as to be located approximately at the center of this outer metal fitting 14, and further between a corresponding outer surface of the inner metal fitting 20 and a pair of flat plates 16, 16. To,
A rubber elastic body 22 is arranged to elastically connect the outer metal fitting 14 (flat plate 16) and the inner metal fitting 20.

The inner metal fitting 20 has a mounting hole 24 in its center for inserting a predetermined mounting shaft on the vehicle body or suspension member side, and also elastically connects the outer surface of the inner metal fitting 20 and the flat plate 16. The connecting rubber elastic body 22 is fixed to the flat plate 16 and the inner fitting 20 by an appropriate method such as vulcanization adhesion, and an intermediate plate 26 is embedded in the intermediate portion thereof. As a result, the spring characteristics of the rubber elastic body 22 in the compression direction are changed, so that the toe angle can be corrected or the toe angle can be compensated for.

On the other hand, a sealed rubber bag 28 made of a predetermined rubber material as a flexible bag is connected to another pair of flat plates 18, 18 constituting the outer metal fitting 14 and a rubber elastic body 2.
2, a pipe-shaped pressure supply port 30 is disposed on the sides of the flat plates 18, 18, is attached to the rubber bag 28, and opens into the rubber bag 28. By being attached through the pair of flat plates 18, 18, the rubber bag 28 is fixed to the flat plates 18, 18, respectively. Although not shown, the rubber bag 28 has a reinforced structure in which a reinforcing material such as canvas is embedded inside, and has a pressure supply port 30 that penetrates the flat plate 18 and projects to the outside. A pressure medium such as pressure fluid supplied from an external pressure supply source is applied to the rubber bag 2 through the rubber bag 2.
8, so that it can effectively withstand the pressure. Furthermore, the rubber material constituting the rubber bag 28 will be selected from a material that is not affected by the pressure medium, but as long as it satisfies such requirements, it may be the same material as the rubber elastic body 22. It makes no difference whatsoever.

Therefore, in a rubber bushing having such a structure, rubber bags 28, 28 are provided inside the rubber elastic body 22 that connects the outer metal fitting 14 and the inner metal fitting 20, symmetrically with the inner metal fitting 20 in between. In contrast, pressure supply ports 30, 3 are connected from an external pressure supply source.
By selectively supplying a predetermined pressure liquid through the rubber bags 28, the rubber bags 28 are selectively inflated, and thereby the flatness of the inner metal fitting 20 is By pressing the facing surface (pressing surface) 32, the inner fitting 20 can be effectively displaced relative to the outer fitting 14 in a direction perpendicular to its center line.

At that time, the rubber bag (pressure chamber) 28 that exerts a pressing action on the inner metal fitting 20 is separate from the rubber elastic body 22 that connects the outer metal fitting 14 and the inner metal fitting 20. Therefore, it becomes possible to arbitrarily select a rubber material different from the rubber elastic body 22 as the rubber material constituting the rubber bag 28, and thereby, the pressure liquid etc. supplied into the rubber bag 28 can be The rubber bag 2 can be made of a rubber material that is not affected by the pressure medium.
8, and it became possible to form a predetermined pressurizing means.

Moreover, in this way, the rubber elastic body 22 and the rubber bag 2
8 is separated from the rubber elastic body 22, so that the rubber elastic body 22 effectively receives the swelling action of the rubber bag 28, and when no pressure is applied to the rubber bag 28,
Since there is no action from the rubber elastic body 22, it is possible to avoid as much as possible unnecessary deformation and fatigue on the rubber elastic body 22 and the rubber bag 28, thereby effectively improving their durability. It can be increased to

Furthermore, since the desired pressurizing means can be easily formed by simply attaching the rubber bag 28 to the inside of the outer metal fitting 14, the conventional structure in which a pressurizing chamber is formed inside the rubber elastic body can be easily formed. In comparison, its production is easy.

Rubber bushings having such characteristics include bushings 8a, 8a, and 8b arranged at symmetrical positions in a rear suspension structure as illustrated in FIG.
8b. More specifically, as shown in Japanese Unexamined Patent Publication No. 58-224802, especially in FIG. 5, pressurized chambers whose volumes change due to deformation of the rubber bushings are made to correspond to each other in each rubber bushing, and the left-right symmetrical position of the vehicle body is The left and right pressurization chambers, which are not located symmetrically, are connected to each other (by cross piping), so that one pressurization chamber of one rubber bushing can be used as a pressure supply source for one pressurization chamber of the other rubber bushing. The configuration uses a pressure chamber. However, when the vehicle turns such that the toe angle changes, the pressurizing chamber of the other rubber bushing, which is not located symmetrically among the left and right rubber bushings, is subjected to a shrinking deformation action, and the pressure medium at a predetermined pressure is then discharged. It is.

In addition to the structure in which the two pressurizing chambers of the left and right rubber bushings are connected by cross piping, the pressurizing chambers of each rubber bushing are connected to an independent pressure supply source such as a pressure tank or an actuator. It is also possible to inflate the pressurizing chambers of each rubber bushing independently by switching with a valve or the like, and by independently controlling the pressurizing chambers of the left and right rubber bushings, , it is possible to control the change in toe angle as described above more effectively and with a greater degree of freedom.

The valves that switch the supply of pressure medium from the independent pressure supply source to each pressurizing chamber of each rubber bushing are connected to appropriate sensors that detect the running state of the vehicle, such as detecting the operation state of the steering wheel that causes the vehicle to turn. This is controlled by a signal from a sensor or the like, and operations such as reducing the change in the toe angle are performed.

Then, by supplying pressure medium from an external pressure supply source to the pressurizing chambers of the rubber bushes attached to the left and right sides of the vehicle body, the pressurizing chambers are bulged, and the central axis (inner) of the rubber bushes is expanded. The suspension geometry can be effectively changed by displacing the cylindrical metal fittings).
In addition to effectively solving the problem of unstable steering due to changes in toe angle when the vehicle turns, etc., the rubber elastic body can be made of a rubber material with the same soft spring characteristics as conventional rubber materials, making it possible to avoid bumps on the road surface. At the same time, it was also possible to ensure isolation characteristics for longitudinal vibrations when riding over.

Of course, the rubber bush according to the present invention is suitably used as a rubber bush for the above-mentioned rear suspension, a so-called member mount, but is not limited thereto, and is applicable to suspensions in which it is desirable to forcibly move the central axis. The structure of the present invention can be applied to all rubber bushings, and thereby the objects and effects of the present invention can be effectively achieved.

Further, in the above example, the outer metal fitting 14 was box-shaped, but it is possible to use a cylindrical one instead of this, and a cylindrical one can be used as the inner metal fitting as well. It makes no difference whatsoever.

Furthermore, in the above example, a rubber bag 28 is used as a flexible bag.
is used, but any flexible bag made of other materials can be used.

In addition, although not listed in detail, the present invention can be implemented with various modifications, improvements, modifications, etc., based on the knowledge of those skilled in the art, without departing from the spirit thereof. It goes without saying that this also includes such embodiments.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view showing the structure of a conventional rear suspension, FIG. 2 is a cross-sectional view showing an example of a rubber bushing according to the present invention, and FIG. 3 is a cross-sectional view taken in FIG. 14: Outer metal fitting, 20: Inner metal fitting, 22: Rubber elastic body, 26: Intermediate plate, 28: Rubber bag, 3
0: Pressure supply port.

Claims (1)

[Scope of Claims] 1. An inner metal fitting attached to either the vehicle body or the suspension member, an outer metal fitting placed outside the inner metal fitting at a predetermined distance and attached to the other of the vehicle body or the suspension member, and In a rubber bushing including a rubber elastic body interposed between an inner metal fitting and an outer metal fitting, a space is created between the inner metal fitting and the outer metal fitting on both sides sandwiching the inner metal fitting in one direction. are elastically connected by the rubber elastic body on both sides of the inner metal fitting in a direction substantially orthogonal to the opposing direction of the space, while a bulgeable member is inserted into both spaces. In addition to arranging the flexible bags, a pressure supply port is provided that penetrates the wall of the outer metal fitting and opens into the flexible bag, and pressure is applied from an external pressure source through the pressure supply port. For a vehicle suspension, wherein the flexible bag is selectively inflated and pressed against the inner metal fitting, and the inner metal fitting can be displaced relative to the outer metal fitting. Rubber button. 2. The rubber bushing according to claim 1, wherein the flexible bag has a reinforcing material such as canvas embedded therein. 3. The surface of the inner metal fitting that faces the flexible bag is a flat surface, and the flexible bag, which is inflated by the supply of pressure, presses the flat surface, thereby causing the outer side of the inner metal fitting to Claim 1 or 2, which causes relative displacement with respect to the metal fittings.
Rubber bushing as described in section. 4. The rubber elastic body is located at an intermediate portion of the connecting portion between the inner metal fitting and the outer metal fitting, respectively.
The rubber bushing according to any one of claims 1 to 3, comprising intermediate plates embedded in positions facing each other with the inner metal fitting interposed therebetween. 5. The rubber bushing according to any one of claims 1 to 4, wherein the rubber bushing is used as a bushing for a rear suspension device. 6. The rubber bushing according to any one of claims 1 to 5, wherein the rubber elastic body and the flexible bag are made of different materials.