JPH1163058A - Rubber bush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide such a rubber bush as being capable of keeping a spring constant, perpendicular to the axial direction, at a specified value and setting other spring constants at desired values. SOLUTION: A supporting ring 5 with a ring stopper rubber 6 pressure contacted against the end of a connection cylinder is fixed to the axial end of an inner cylinder 2, separately of a rubber elastic body 3, and the hardness and compression ratio of the stopper rubber 6 is increased, so that a spring rigidity in the axial direction and in the wrench direction can be increased, separately of the spring constant of a rubber elastic body 3, and the steering stability is improved as riding comfortableness remains unchanged. The supporting ring 5 with the stopper rubber which is mounted later on a rubber bush mainbody 1a can be simply vulcanized and molded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber bush used for a connecting portion such as a suspension arm of an automobile, and more particularly to a rubber bush most suitable for changing a spring constant in an axial direction and a twisting direction. .

[0002]

2. Description of the Related Art A rubber bush is used for elastically supporting each connecting portion of a vehicle suspension. In order to improve steering stability and ride comfort and to prevent vibration and noise, Conventionally, various forms are provided.

In a rubber bush 100 shown in FIG. 4, a rubber-like elastic body 103 having a rubber flange 102 is vulcanized and bonded around an inner cylinder 101 serving as a shaft member.
This is a so-called inner cylinder bonded outer cylinder press-fit type anti-vibration rubber in which a connection cylinder 105 such as a suspension arm is externally press-fitted into the fitting portion 104 of No. 03. This outer cylinder press-fit type is effective when a large compression ratio is applied to the rubber-like elastic body 103 to increase the spring constant in the direction perpendicular to the axis.

[0005] A rubber bush 107 shown in FIG. 5 has a rubber-like elastic body 110 interposed between an inner cylinder 108 serving as a shaft member and an outer cylinder 109 arranged around the inner cylinder. This is a so-called inner / outer cylinder bonding type vibration damping rubber in which a rubber-like elastic body 110 is vulcanized and bonded to 109. is there.

[0005]

By the way, the rubber bush used for a suspension of an automobile or the like has an axial direction,
A desired spring constant is required in the direction perpendicular to the axis and in the torsion direction (direction of rotation about the axis), and also in the twisting direction (direction inclined with respect to the axis A). In general, in a rubber bush for a suspension, the spring constant in the direction perpendicular to the axis affects the riding comfort, and if it is soft, the riding comfort is improved. Also,
In particular, the spring constants in the axial direction and the prying direction affect the steering stability, and the higher the spring constant, the better the steering stability.

In the rubber bush 100 with the flange rubber 102 of the press-fit type of the inner cylinder and the outer cylinder shown in FIG. 4, since the flange rubber 102 is formed, a desired spring constant is obtained in the direction perpendicular to the axis and the axial direction. It is also possible to obtain a certain degree of spring stiffness. Further, in the rubber bush 107 of the inner and outer cylinder bonding type shown in FIG. 5, a desired spring constant is obtained in the direction perpendicular to the axis, and the axial direction is adapted with a certain degree of spring rigidity.

However, in order to increase the steering stability, it is desired to obtain a high spring constant in both the axial direction and the twisting direction while keeping the spring constant in the direction perpendicular to the axis, as shown in FIGS. 4 and 5. In the embodiment, there is no other method than increasing the rubber hardness of the rubber-like elastic body, and if it is set so, the spring constant in the direction perpendicular to the axis increases.

In view of the above, it is an object of the present invention to provide a rubber bush in which the spring constant in the axial direction and the prying direction can be set to desired values while maintaining the spring constant in the direction perpendicular to the axis at a predetermined value.

[0009]

Means for Solving the Problems In order to achieve the above object, the present inventors have separated the rubber portion involved in the spring constant in the axial direction and the twisting direction from the rubber-like elastic body of the main body, and As a result, desired spring characteristics are obtained, and the present invention has been completed.

That is, a structure is adopted in which a ring-shaped support ring with a stopper rubber that contacts the end of the connecting cylinder is fixed to at least one end in the axial direction of the shaft member, separately from the rubber-like elastic body. If the hardness or the compression ratio of the stopper rubber is appropriately selected, the spring constant of the rubber-like elastic body is separately determined.
The spring constant in the axial direction and the twisting direction can be set, and the spring characteristics of the entire rubber bush can be appropriately selected.

Therefore, among the spring constants of the rubber-like elastic body,
This is advantageous when it is desired to change only the spring constant in a specific direction such as the axial direction or the twisting direction. Since the stopper rubber is in contact with the end of the connecting cylinder, the spring constant in the torsion direction around the axis A can be changed. Further, in this case, since the support ring with the stopper rubber is of a type that is formed separately from the vulcanization molding of the rubber-like elastic body in the rubber bush body and then attached later, the vulcanization molding process can be easily performed. .

[0012] Such a structure is either a rubber bush of a type in which an end connecting cylinder of a connecting member such as a suspension arm is directly press-fitted around a rubber-like elastic body without an outer cylinder, or a rubber bush with an outer cylinder. It can also be adopted in the system. Also,
Since the support ring with the stopper rubber has a role of supplementing the spring constant of the rubber-like elastic body, as the rubber-like elastic body, for example, one having a through hole or one having an intermediate cylinder interposed, Various shapes can be employed.

Here, the shaft member may be a solid member in addition to the inner cylinder as shown in FIGS. The support ring fitted to the shaft member may be arranged at one end instead of being arranged at both ends of the shaft member.

The support ring is generally formed of a ring-shaped metal plate, but a hard resin or the like having the same rigidity as the metal plate may be used. The support ring can be fitted to the shaft member by either an insertion method or an adhesion method such as welding. However, the insertion method is preferable in consideration of production efficiency. In order to prevent the support ring from falling off, it is preferable to form a hub on the center hole wall from the viewpoint of increasing the contact area with the shaft member and increasing the rigidity.

The support ring and the ring-shaped stopper rubber are fixed to each other by a vulcanization bonding method in which unvulcanized rubber is adhered to the support ring and vulcanized and bonded, or the stopper rubber is vulcanized after being vulcanized. Any of the sticking baking methods can be adopted.

The spring constant of the stopper rubber can be arbitrarily selected according to the spring characteristics required for the product. As a means for setting the spring constant, it is optimal to make the rubber-like elastic body and the stopper rubber different in hardness. It is. This makes it possible to easily obtain desired spring constants in the axial direction, the direction perpendicular to the axis, the torsion direction, and the twisting direction of the entire rubber bush. If the rubber hardness of the stopper rubber is set higher than that of the rubber-like elastic body, the spring constant in the direction perpendicular to the axis of the rubber bush is maintained,
Since the spring constants in the axial direction and the twisting direction can be increased, the steering stability can be significantly improved while maintaining the riding comfort performance.

In order to increase the spring constants of the stopper rubber in the axial direction and the prying direction, in addition to increasing the rubber hardness, a state in which the contact pressure between the stopper rubber and the connecting cylinder at the time of insertion into the connecting cylinder is increased, that is, Also, it is possible to increase the spring constant by fitting the support ring to the shaft member in a state where the compression ratio of the stopper rubber is increased and the preliminary compression is given. Further, if the pre-compression is given to the stopper rubber, the durability of the stopper rubber is also improved.

The contact pressure between the end of the connecting cylinder and the stopper rubber can be arbitrarily set according to the use conditions in order to obtain a desired value as the spring stiffness in the axial direction and the twisting direction. Therefore, a low contact pressure may be set when a low spring stiffness is required, and a strong contact pressure may be set when a high spring stiffness is required.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded view of a rubber bush showing the first embodiment, and FIG. 2 is a cross-sectional view showing a state in which the rubber bush is similarly fitted into a connecting cylinder formed at an end of a suspension arm.

The rubber bush 1 according to the first embodiment has a rubber-like elastic body 3 on an outer peripheral portion of an inner cylinder 2 serving as a shaft member.
Are vulcanized and bonded to form a rubber bush body 1a. A connecting cylinder 4 such as a suspension arm is fitted around the rubber-like elastic body 3 and support rings 5 are attached to both ends of the inner cylinder 2 in the axial direction.
And a ring-shaped stopper rubber 6 is fixed to the inside of the support ring 5 in the axial direction, and the stopper rubber 6 is pressed against the end of the connecting cylinder 4 to apply preliminary compression.

The inner cylinder 2 is a thick cylindrical pipe,
The central outer peripheral portion is a fixing portion of the rubber-like elastic body 3, and both end portions are fitting portions of the support ring 5. A bolt (not shown) for connecting to a bracket (not shown) on the vehicle body side passes through the center hole 7 of the inner cylinder 2.

When the rubber-like elastic body 3 is press-fitted into the connecting cylinder 4 of the suspension arm, the center part 3a in the axial direction has an end part 3b so that a uniform compression ratio can be obtained in the axial direction.
It is formed in a barrel shape with a larger diameter than that. Examples of the material of the rubber-like elastic body 3 include natural rubber or synthetic rubber generally used as a vibration-proof rubber, for example, SBR (styrene butadiene rubber), BR (butadiene rubber), IR (isoprene rubber), NBR ( Acrylic nitrile butadiene rubber), CR (chloroprene rubber), IIR (butyl rubber), EPDM (ethylene propylene rubber), urethane elastomer or the like is used. A compounding agent such as a vulcanizing agent, a vulcanization accelerator, an antioxidant, a reinforcing agent, a filler, and a softening agent is added to these raw rubbers, and a predetermined elastic modulus, mechanical strength, dynamic characteristics, fatigue characteristics, etc. So that you can get

The support ring 5 is made of a ring-shaped formed rolled steel, and has a support portion 5a to which a stopper rubber 6 is adhered and a shaft wall from a hole wall of a central hole 8 for fitting to the inner cylinder 2. And a hub portion 5b formed to project inward in the direction. The support ring 5 presses the rubber bush body 1a into the connection cylinder 4 of the suspension arm,
It is inserted with a predetermined press input, for example, 2-3
Even when press-fitting is performed with a press-fitting load of tf, the detachment load is maintained at about 500 kgf.

The stopper rubber 6 may have the same composition as that of the rubber-like elastic body 3, but in the present embodiment, the rubber hardness different from that of the rubber-like elastic body 3 is obtained by changing the ratio of various compounding agents. I am trying to be. The hardness and spring constant of the stopper rubber 6 vary depending on the use conditions.
JIS hardness Hs of rubber-like elastic body: 58 °, spring constant in the direction perpendicular to the axis: 25,000 N / m, spring constant in the axial direction: 700 N / m
JIS rubber hardness Hs7 of the stopper rubber
0 °, the axial spring constant can be set to 15,000 N / m, and the torsion spring constant can be set to 100 N · m / deg.

The stopper rubber 6 is fixed to the inside of the support ring 5 in the axial direction by vulcanization bonding. The fixing position of the stopper rubber 6 to the support ring 5 is set at a position where the stopper rubber 6 is pressed against the end of the connecting cylinder 4. Have been.

In the rubber bush 1 constructed as described above, in addition to the rubber-like elastic body 3, the rubber hardness of the stopper rubber 6 for compensating the spring constant in a specific direction (axial direction and twisting direction) is determined. Because it is set higher than the rubber hardness of, the spring stiffness in the axial direction can be increased,
Even when a force in the prying direction acts on the rubber bush 1, the connecting cylinder 4 slides on the contact surface with the stopper rubber 6 to exert a frictional force, so that the prying rigidity also increases. Further, since the stopper rubber 6 is in contact with the end of the connecting cylinder 4 at a predetermined pressure, the spring rigidity in the torsion direction can be increased.

In this case, if the rubber hardness of the rubber-like elastic body 3 in the direction perpendicular to the axis is kept as it is, the rubber bush is soft in the direction perpendicular to the axis and has high rigidity in the axial direction and the twisting direction, and the riding comfort performance is maintained. As it is, the steering stability can be significantly improved. Since the contact pressure between the stopper rubber and the connecting cylinder is increased during insertion into the connecting cylinder and the pre-compression is applied to the stopper rubber 6, the support ring 5 is fitted to the inner cylinder 2; The durability will also be improved.

FIG. 3 is a sectional view showing the second embodiment. The rubber bush 1 according to the second embodiment has a rubber-like elastic body 3 interposed between an inner cylinder 2 and an outer cylinder 10 arranged therearound. A support ring 5 is fitted to both ends of the arm, a ring-shaped stopper rubber 6 is fixed to the inside of the support ring 5 in the axial direction, and the stopper rubber 6 is externally fitted into the outer cylinder 10 by press-fitting. Is pressed into contact with the end portion of the.

The outer cylinder 10 is formed in a thin cylindrical shape from STKM material or the like, and the rubber-like elastic body 3 is interposed between the outer cylinder 10 and the inner cylinder 2 and vulcanized and bonded. .
The rubber-like elastic body 3, the inner cylinder 2, and the support ring 5 with the stopper rubber 6 have the same configuration as in the first embodiment.

In the rubber bush 1 after molding, the outer cylinder 10 is press-fitted into the connecting cylinder 4 of the suspension arm.
Thereafter, the support ring 5 with the stopper rubber 6 is press-fitted into the end of the inner cylinder 2 and the stopper rubber 6 is pressed against the end of the connecting cylinder 4 to assemble the suspension arm.

In the second embodiment, since the inner and outer cylinders are of the adhesive type, the outer cylinder 10 is reduced in diameter to give a preliminary compression to the rubber-like elastic body 3 to improve the durability of the rubber. Can be done. Other functions and effects are the same as those of the first embodiment, and the description thereof is omitted here.

[0032]

As is apparent from the above description, according to the rubber bush according to the present invention, at least one end in the axial direction of the shaft member is in contact with the end of the connecting cylinder separately from the rubber-like elastic body. The structure of fixing the support ring with the rubber stopper is adopted, so that the hardness or compression ratio of the stopper rubber is selected, and the spring constant in the axial direction and the prying direction is set separately from the spring constant of the rubber-like elastic body. Can be set,
In addition, since the support ring with the stopper rubber is of a type that is formed separately from the vulcanization molding of the rubber-like elastic body in the rubber bushing body and then attached later, the vulcanization molding process can be easily performed.

Further, by making the rubber hardness of the rubber-like elastic body different from that of the stopper rubber, desired spring characteristics can be easily obtained as a whole rubber bush.

Furthermore, if the rubber hardness of the stopper rubber is set higher than the rubber hardness of the rubber-like elastic body, the spring constant in the axial direction and in the twisting direction is maintained while the spring constant in the direction perpendicular to the axis of the rubber bush is maintained. Since it can be set high, the handling stability can be significantly improved while maintaining the riding comfort performance. Further, if preliminary compression is given by bringing the stopper rubber and the connecting cylinder into pressure contact with each other, the durability of the stopper rubber can also be improved.

[Brief description of the drawings]

FIG. 1 is an exploded view of a rubber bush showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a rubber bush is similarly fitted into a connecting cylinder of a suspension arm.

FIG. 3 is a cross-sectional view of a rubber bush showing a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of a conventional so-called inner cylinder bonded outer cylinder press-fit type rubber bush.

FIG. 5 is a cross-sectional view of a conventional rubber bush of a so-called inner and outer cylinder bonding type.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rubber bush 1a Rubber bush main body 2 Inner cylinder 3 Rubber-like elastic body 4 Connecting cylinder 5 Support ring 6 Stopper rubber

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshio Ihara 1-17-18 Edobori, Nishi-ku, Osaka-shi, Osaka Toyo Tire & Rubber Co., Ltd. (72) Inventor Akinori Arai 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto (72) Inventor Shuichi Kobayashi 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Kazuhiro Horikoshi 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation

Claims (5)

[Claims] 1. A rubber-like elastic body is fixed around a shaft member,
In a rubber bush in which a connecting cylinder of a connecting member is fitted around the rubber-like elastic body, a support ring is fitted to at least one end in the axial direction of the shaft member, and a ring is provided inside the support ring in the axial direction. A rubber bush, wherein a stopper rubber in a shape of a circle is fixed, and the stopper rubber is in contact with an end of the connecting cylinder. 2. A rubber bush wherein a rubber-like elastic body is interposed between a shaft member and an outer cylinder arranged around the shaft member.
A connecting member in which a support ring is fitted to at least one end in the axial direction of the shaft member, a ring-shaped stopper rubber is fixed to the inside of the support ring in the axial direction, and the stopper rubber is externally fitted and pressed into the outer cylinder. A rubber bush, characterized in that it comes into contact with the end of the connecting cylinder. 3. The rubber bush according to claim 1, wherein the rubber elastic body and the stopper rubber have different rubber hardness. 4. The rubber bush according to claim 3, wherein the rubber hardness of the stopper rubber is set higher than the rubber-like elastic body. 5. The rubber bush according to claim 1, wherein the stopper rubber is pressed against the end of the connecting cylinder to perform pre-compression.