JP3507937B2 - Elastic bush - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elastic bush mainly used by being incorporated in a suspension mechanism of an automobile.

[0002]

2. Description of the Related Art Conventionally, in a suspension of a vehicle such as an automobile, a connecting portion between the vehicle body and the suspension, for example, a connecting portion between an arm member of the suspension supporting a wheel and a member on the vehicle body side is elastic for the purpose of cushioning. Bush is used.

For example, in a torsion beam type suspension of an automobile as shown in FIG. 6, a trailing arm (60) is pivotally supported on the vehicle body side by a bush part (61) at its front end and a wheel (70) at its rear end part. Is rotatably supported, and the bush portion (61) includes an elastic bush (A1) supported by a bush shaft (not shown) extending inward and outward of the vehicle.

As shown in FIG. 7, the elastic bush (A1) includes a metal inner cylinder (101) and an outer cylinder (102) which are concentrically arranged, and are made by a vulcanizing adhesive means between the two cylinders. It is connected via a rubber elastic body (103) arranged, and is usually fixed to the outer cylinder (102) at the end of an arm member (106) such as the trailing arm by a press-fitting means or the like. The bush shaft is inserted into the inner cylinder (101) for use.

In order to improve the spring characteristic of the elastic bush in the axial direction, the inner and outer cylinders (1
01) and (102) are provided with flanges (111) and (121) at different axial positions, and a rubber elastic body (103) is provided between the flanges (111) and (121).
There is a form in which the flange portion (131) of (1) is integrally extended.

Further, as shown in FIG. 8, two bushes (110) (110) having the same structure as described above are press-fitted into the arm member (106) with their end portions having no flanges facing each other. It is also considered to do.

[0007]

In the case of the elastic bush (A1) of the type having the above-mentioned flange, although the spring characteristic in the axial direction is improved, the arm member (106) is twisted by the swing in the direction of the arrow in the figure. May occur.

For example, the trailing arm (6
The elastic bush (A1) in 0) supports the arm so that it can swing up and down about the bush shaft, but the arm swings even in a plane (generally horizontal plane) including the arm and the bush shaft. This may cause the elastic bush (A1) to twist.

When such twisting occurs, the flange portion (131) of the rubber elastic body (103) is compressed or pulled at a portion of the elastic bush (A1) facing the extending direction of the arm member (106). There is a problem that the deformation (strain) becomes large and, for example, the outer peripheral portion of the flange portion (131) is squeezed out or an excessive tensile force is exerted, and the fatigue is reduced due to the repeated fatigue of the flange portion (131).

In particular, as disclosed in Japanese Utility Model Laid-Open No. Sho 60-194638, in order to adjust and improve the spring characteristic in the direction perpendicular to the axis, which is required according to the situation of use, the relative elasticity of the rubber elastic body between the inner and outer cylinders. Even when a cavity called "currant" is provided at the facing position to lower the spring constant in the direction perpendicular to the axis where the currant portion exists, in the case of a bush having a flange, the same problem as described above occurs. Occurs.

The present invention has been made in view of the above, and maintains good spring characteristics in the axial direction and the direction perpendicular to the axis, and moreover, compresses the rubber elastic body by the twisting force due to the swing of the arm member. Excellent in reducing strain caused by tension,
It is intended to provide an elastic bushing which can improve durability and whose spring characteristics can be easily adjusted.

[0012]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems. According to the invention of claim 1, a rubber elastic body is provided between the inner cylinder and the outer cylinder, and one end thereof is provided. An elastic bush provided with a flange on the arm member and attached to an arm member, wherein the flange portion of the rubber elastic body is provided only on both side portions facing each other across the inner cylinder in the extending direction of the arm member , It is characterized in that each of them has an engraved portion.

[0013] With this elastic bushes, only on each side portion, each example <br/> counterbore provided opposed across the inner cylinder in the extending direction of the arm member distortion increases by prying from the arm member As a result, the twisting force due to the swing of the arm member can be absorbed by the gouging portion, the flange portion of the rubber elastic body is not largely compressed and pulled, the strain is reduced, and the durability is improved. On the other hand, the original spring characteristics can be maintained in the axial direction and the axis-perpendicular direction.

According to a second aspect of the present invention, in the elastic bush, the arm member is a suspension arm, and the cursed portion is provided at a position of a main body of the rubber elastic body in a vehicle vertical direction. .

According to this elastic bush, the scooping portion is located opposite to the extending direction of the suspension arm, so that the prying force due to the swinging of the arm in the substantially horizontal plane is effectively absorbed and the durability is improved. Since it has an advantageous structure and the curls are provided in the vertical direction of the vehicle, the vertical vibration of the suspension arm can be absorbed with a soft desired spring constant, and the riding comfort can be improved.

The invention of claim 3 is characterized in that the two bushes according to claim 1 or 2 are attached to an arm member with their end portions having no flange portion facing each other. And

In this case, since it has a form in which flanges having a cutout portion are provided at both ends thereof in a state of being attached to the arm member, the spring characteristic as an elastic bush, that is, the spring characteristic in the axial direction and the direction perpendicular to the axis. Furthermore, the spring characteristic against twisting can be improved, and its adjustment and setting become easy.

According to a fourth aspect of the invention, when the two bushes are opposed to each other, the inner cylinder of one bush is press-fitted into the inner cylinder of the other bush.

In this case, the combined connection of both bushes is facilitated, and the amount of press-fitting of the inner cylinder makes it possible to easily apply preliminary compression for the purpose of reducing tensile strain to the flange portion of the rubber elastic body. Therefore, it becomes easy to adjust the preliminary compression amount.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing an elastic bush (A) of a first embodiment of the present invention, and FIG. 2 is a front view of the elastic bush (A).

In this elastic bush (A), a metallic cylindrical inner cylinder (1) and an outer cylinder (2) arranged concentrically are
These two cylinders are integrally connected via a rubber elastic body (3) in the shape of a cylinder arranged by vulcanizing and bonding means, and a flange (8) is provided at one axial end thereof. . That is, the inner cylinder (1) is formed to be longer than the outer cylinder (2), and the ends of the inner cylinder (1) and the outer cylinder (2) are axially different from each other and have a required gap therebetween. (11) (21)
And a flange portion (31) of the rubber elastic body (3) sandwiched between the flanges (11) and (21).
Are extended and these constitute the flange (8).

The outer cylinder (2) is attached to the end of the arm member (6) such as the trailing arm of the suspension by press fitting means or the like. A bush shaft (not shown) supported by the vehicle body side member is inserted into the inner cylinder (1).

The flange portion (31) of the rubber elastic body (3) is distorted when both side portions facing each other with the inner cylinder (1) sandwiched therebetween, particularly when a prying force is applied by the arm member (6). The portions facing each other in the extending direction of the enlarged arm member (6) are respectively provided with the cut-out portions (4) and (4) which are recessed from the outer peripheral side by the rounded curved surface.

If the circumferential spread angle of the cutout portion (4) is larger than 90 °, the spring constant in the axial direction is lowered and the effect of providing the flange portion is reduced, and the angle is smaller than 45 °. If so, the effect of absorbing the prying force becomes small, so that the cutout portion (4)
Is 45 ° to 9 around the axis in the circumferential direction as shown in FIG.
It shall have a spread (length) in the angular range (E) of 0 °.

Regarding the above-mentioned cut-out portion (4), the curvature radius (Re) of the point (P) at the deepest portion in the cross-section is set to 1 mm or more in FIG. The distance (C) from the inner peripheral surface to the deepest point (P), and the distance (D) from the inner surface of the flange (11) of the inner cylinder (1) to the deepest point (P). , The flange portion (31) of the rubber elastic body (3), respectively
The thickness (T) and the space (B) between the inner and outer cylinders (1) and (2) are preferably set to satisfy the following conditions. 0.2B ≤ C ≤ 0.8B D ≤ 0.5T (however, T> 30mm)
.

That is, when the radius of curvature (Re) of the point (P) at the deepest portion is less than 1 mm, cracks are likely to occur from this portion. If the distance (C) from the inner peripheral surface of the outer cylinder to the point (P) at the deepest portion is smaller than 0.2B, the cut-out portion becomes shallow and the expected effect cannot be obtained.
If it is larger than 8B, the cutout portion becomes too deep and buckling is likely to occur when compression is applied, resulting in a problem in durability. If the distance (D) from the flange surface of the inner cylinder to the deepest point (P) exceeds 0.5T, buckling also tends to occur during compression, which is not preferable.

In the figures, (5) and (5) are both inner and outer cylinders (1).
Between the (2) and the rubber elastic body (3) is a curled portion provided in the main body portion (32) and extending parallel to the axial center. The curled portions (5) and (5) are provided with the arm member (6). In the case of a suspension arm such as a trailing arm extending in the vehicle front-rear direction shown in FIG. 6, the suspension arm is provided so as to face each other in the vehicle vertical direction position of the main body portion (32) as shown in FIGS. To be As a result, the spring constant is set low in the vertical direction of the vehicle.

The cut portion (5) is set in an angular range (F) of 120 ° or less (usually 60 to 120 °) when viewed from the axial center in the circumferential direction. Moreover, as the currant part (5),
In addition to the case where the rubber elastic body (3) is provided so as to penetrate in the axial direction as shown in the figure, it may be provided without being penetrated in the axial direction. Further, the outer cylinder (2) is attached to the outer periphery of the rubber elastic body (3).
It can also be provided in the form of a recess that contacts the inner peripheral surface.

The elastic bush (A) of the above embodiment is
The outer cylinder (2) is press-fitted into the mounting hole of the arm member (6) in the suspension for mounting. For example, in the torsion beam type suspension of FIG.
The elastic bush (A) of the present invention is attached to the bush portion (61) at the front end of the trailing arm (60) extending in the vehicle front-rear direction, and the bush shaft in the vehicle width direction is attached to the inner cylinder (1).
Insert and use.

At this time, in the elastic bush (A), the flange (8) is located on the inner side of the vehicle, and the cutout (5) is in the extending direction of the arm member (6) such as the trailing arm. It is attached to the arm member (6) so that it is positioned to face a certain vehicle front-rear direction, and the currant portion (5) is positioned to face the vehicle vertical direction.

In this use, the original spring characteristics can be maintained in the axial direction and the direction perpendicular to the axis, and
By the rocking of the arm member (6), for example, the rocking of the trailing arm in a substantially horizontal plane, the twisting force transmitted from the arm member (6) can be effectively absorbed by the gouging portion (4), and the rubber elastic body ( Distortion due to compression and tension in the flange portion (31) of 3) is reduced, and durability is improved. At the same time, the spring constant in the vertical direction is reduced by the currant portion (5) provided so as to face the vehicle in the vertical direction, the vertical vibration of the arm member (6) of the suspension can be softly absorbed, and the riding comfort is also improved.

FIG. 4 shows a second embodiment of the elastic bush (A) of the present invention and is a sectional view of the same angle as FIG. In FIG. 4, the same components as those of the first embodiment are designated by the same reference numerals.

In this embodiment, the two bushes (10) (10) having the same construction as those of the first embodiment are provided on the side not having the flange (8) with respect to the mounting holes of the arm member (6). Are press-fitted so as to face each other.

That is, the two bushes (10) (1
0) has a flange portion (31) of a rubber elastic body (3), which is sandwiched between the flanges (11) and (21) of the inner and outer cylinders (1) and (2) at one end, respectively. Opposed to the extending direction of the arm member (6) of the flange portion (31)
The cutout portions (4) similar to those in the above-described embodiment are provided only on both sides . Further, the body portion (32) of the rubber elastic body (3) is provided with a curled portion (5) at a portion facing in the vehicle vertical direction.

Then, this bush (10) (10)
Are press-fitted and fixed from both sides into the mounting holes of the arm member (6) so that the end sides not having the flanges (8) face each other, thereby being combined and coupled.

For this reason, the length of the outer cylinder (2) is made slightly shorter than 1/2 of the width of the arm member (6) so that the flange (21) can be press-fitted to the position where it abuts on the arm end face. It is good to keep it. Both bushes (10)
The cutout portion (4) and the cutout portion (5) of (10) are provided on the same line so as to correspond in parallel.

In the case of this elastic bush (A), due to the combination of the two bushes (10) and (10), there will be a flange having a cutout at both ends, so the spring characteristics when used as an elastic bush, That is, the spring characteristics in the axial direction and the axis-perpendicular direction, and further the spring characteristics against the twisting force can be favorably maintained, and the durability can be further improved. It is also possible to adjust the characteristics.

FIG. 5 shows a third embodiment of the elastic bush (A) of the present invention and is a sectional view of the same angle as FIG. Also in this FIG. 5, the same components as those of the first embodiment are designated by the same reference numerals.

In this embodiment, as in the second embodiment, 2
When two bushes are opposed to each other and attached to the arm member (6), in particular, one end of the bush (10a) opposite to the flange (11) of the inner cylinder (1) is extended,
The inner cylinder (1) of the other bush (10b) is press-fitted and joined to the outer periphery of the extension (1a) of the inner cylinder (1) of the one bush.

That is, the inner cylinder (1) is replaced with the rubber elastic body (3).
Insert the extension (1a) of the inner cylinder (1) of the longer bush (10a) into the mounting hole of the arm member (6), press the outer cylinder (2) into the mounting hole, and the other The outer cylinder (2) of the bush (10b) is press-fitted from the opening opposite to the mounting hole, and the inner cylinder (1) is press-fitted to the extension (1a) of the inner cylinder. Note that the cutout portion (4) is provided in the extending direction of the arm member (6), and that the cutout portion (5) is arranged in the vehicle vertical direction is the same as in the above-described embodiment.

In the case of this embodiment, both bushes (10a)
In addition to facilitating the combined connection of (10b), it is easy to give a precompression for the purpose of reducing tensile strain to the rubber elastic body (3) by using the press-fitting of the inner cylinder (1). It is possible, and in particular the precompression can also be adjusted by means of the above-mentioned press fit. Also, as shown, the bush (10b)
By press-fitting the inner cylinder (1) of the
The bush (10a) and the bush (10b) are easily coaxial.

[0043]

As described above, the elastic bushing of the present invention is provided with the cutout portion so as to effectively absorb the prying force due to the swing of the arm member in relation to the extending direction of the arm member. In addition, the spring characteristics in the axial direction and the axis-perpendicular direction can be maintained satisfactorily, and further, the compression effect due to the twisting force from the arm member and the strain reduction effect due to the tension are excellent, and the durability can be improved.

In particular, in the suspension arm extending in the vehicle front-rear direction, by providing a cutout portion in the vertical direction of the vehicle together with the above-mentioned cutout portion, the durability is improved by absorbing the prying force and the vertical vibration is reduced. It is possible to achieve both improvement in riding comfort.

Further, by making the two bushes face each other, the degree of freedom in setting the spring characteristics is high, and in particular precompression can be easily applied to the rubber elastic body.

[Brief description of drawings]

FIG. 1 is a sectional view taken along line XX of FIG. 2 showing an elastic bushing according to a first embodiment of the present invention.

FIG. 2 is a front view of the above elastic bush.

FIG. 3 is an enlarged cross-sectional explanatory view of a cutout portion.

FIG. 4 is a sectional view of the same portion as FIG. 1 showing an elastic bushing according to a second embodiment of the present invention.

FIG. 5 is a sectional view of the same portion as FIG. 1 showing an elastic bushing according to a third embodiment of the present invention.

FIG. 6 is a perspective view showing an example of a torsion beam suspension.

FIG. 7 is a vertical sectional view showing an example of a conventional elastic bush.

FIG. 8 is a vertical cross-sectional view showing another example of a conventional elastic bush.

[Explanation of symbols]

(A) Elastic bush (1) Inner cylinder (2) Outer cylinder (3) Rubber elastic body (4) Egg section (5) Currant (6) Arm member (8) Flange (10) (10a) (10b) Bush (11) Inner cylinder flange (21) Flange of outer cylinder (31) Flange part of rubber elastic body (60) Trailing arm

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroshi Ono 1-17-18 Edobori, Nishi-ku, Osaka-shi, Osaka Toyo Tire & Rubber Co., Ltd. (56) Reference JP-A-6-179315 (JP, A) JP Flat 8-156557 (JP, A) Actual opening Sho 52-139988 (JP, U) Actual opening Sho 62-62041 (JP, U) Actual opening Sho 62-27239 (JP, U) Actual opening Sho 59-93978 (JP , U) Actual Development Sho 62-177936 (JP, U) Japanese Patent Publication 3-20132 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16F 1/38 F16F 15/08

Claims (4)

(57) [Claims] 1. An elastic bush having a rubber elastic body interposed between an inner cylinder and an outer cylinder, a flange provided at one end, and attached to an arm member, the flange portion of the rubber elastic body. In the extending direction of the arm member, only on both side portions facing each other with the inner cylinder interposed therebetween.
Elastic bushing Re gouge portion, characterized in that the thus provided. 2. The elastic bush according to claim 1, wherein the arm member is a suspension arm, and a curled portion is provided at a position of a main body of the rubber elastic body in a vehicle vertical direction. 3. An elastic bush, characterized in that the two bushes according to claim 1 or 2 are attached to an arm member with their end portions having no flanges facing each other. 4. The elastic bush according to claim 3, wherein the inner cylinder of one bush is press-fitted into and joined to the inner cylinder of the other bush.