WO2004070229A1

WO2004070229A1 - Vibration isolator

Info

Publication number: WO2004070229A1
Application number: PCT/JP2003/001402
Authority: WO
Inventors: Naoki Yamaguchi; Yoshitaka Ishimoto
Original assignee: Toyo Tire & Rubber Co., Ltd.
Priority date: 2003-02-10
Filing date: 2003-02-10
Publication date: 2004-08-19
Also published as: JP3937352B2; AU2003207048A1; JPWO2004070229A1

Abstract

A vibration isolator, comprising an inner tube (10), an outer tube (12) surrounding the inner tube (10), and a rubber elastic body (14) installed therebetween, wherein a plurality of axial rigid ribs (24) axially extending from the flange (18) side end part of the outer tube (12) are provided on the outer peripheral surface of the outer tube (12) at intervals in circumferential direction to increase a press-fitting workability when the outer tube (12) is mounted in a tubular holder (4) and to assure the force of extraction thereof from the holder, and a circumferentially extending rubber annular rib (26) is provided on the outer tube (12) at the anti-flange side end part.

Description

Description Anti-vibration device [Technical field]

The present invention relates to an anti-vibration device, and more particularly to an anti-vibration device suitable as a body mount used for mounting a vehicle underbody member or the like. .

(Background technology)

Conventionally, this type of body mount includes an inner cylinder attached to one of the underbody member and the body, an outer cylinder attached to the other, and a rubber elastic body fixed between the two cylinders. Is known.

Such a body mount is mounted by press-fitting the outer cylinder into a cylindrical holder provided on one of the underbody member and the body, but the conventional outer cylinder is press-fitted into the holder. Since the part has a cylindrical shape with a constant outer diameter in the axial direction, it requires a very large pressurized force, and therefore has the drawback of poor workability in mounting to the holder.

Therefore, Japanese Patent Application Laid-Open Publication No. Hei 4-327033 discloses a rubber provided with a multistage annular lip extending in the circumferential direction on the outer peripheral surface of the outer cylinder in order to improve the attachment of the outer cylinder to the holder. It is disclosed that a film is formed to prevent the annular rib from coming off when attached to a holder, and to improve seating.

However, in the structure in which the rubber film is provided on the entire outer peripheral surface of the outer cylinder as described above, the press-fitting load is reduced while the unloading load is also reduced, so that the use environment is limited.

Further, when the annular ribs are provided in multiple stages on the outer peripheral surface of the outer cylinder as described above, there is a possibility that the annular lip may be caught every time when each of the annular ribs is climbed when being pressed into the holder. Also, every time the vehicle gets over each annular rib, a beak of press-in force is generated, and the press-in workability is impaired. Considering the workability of attaching the outer cylinder to the holder, Then, it is desirable that such an annular lip be as small as possible.

[Disclosure of the Invention]

The present invention has been made in view of such a point, and an object of the present invention is to improve the workability of attaching an outer cylinder to a cylindrical holder in the above-described vibration isolator. Another object of the present invention is to secure the removal force from the holder while improving the workability of attaching such an outer cylinder to the holder.

The vibration isolator according to the present invention includes an inner cylinder, an outer cylinder surrounding the inner cylinder, and a rubber elastic body interposed between the inner cylinder and the outer cylinder to couple the two cylinders to each other. A plurality of axial ribs arranged at intervals in the circumferential direction and extending in the axial direction, and an annular rib extending in the circumferential direction is provided at one axial end of the outer cylinder. It is.

In this vibration isolator, since the annular rib is only provided at one end in the axial direction, the possibility of winding the annular rib when press-fitting the cylindrical holder and the peak number of press-fitting can be further reduced. Further, the pressure input can be reduced as compared with the case where the outer diameter of the outer cylinder is constant in the axial direction. Therefore, the workability of attaching the outer cylinder to the holder is improved. In addition, the combination of the annular rib and the above-mentioned axial rib provides excellent stability against input perpendicular to the axis.

In the vibration damping device of the present invention, the outer cylinder is provided with a flange extending radially outward at one end in the axial direction, and the annular rib is provided at an end of the outer cylinder opposite to the flange. It is preferable that the axial lip extends axially from an end on the flange side and terminates so as not to cross the annular rib. For example, the axial rib may be terminated substantially at the center in the axial direction of the press-fitting range into the holder. In this case, the annular rib can prevent intrusion of water, dust, and the like from the end on the side opposite to the flange.

The axial rib is preferably a rigid rib made of metal, resin, or the like, and the annular rib is preferably a rubber rib fixed to the outer peripheral surface of the outer cylinder. As a result, when pressed into the cylindrical holder, the flange with the axial rib The flange side is a press-fit portion with a rigid body, and the opposite flange side with the annular rib is a press-fit portion with rubber, and both advantages can be utilized. That is, the pressure input can be reduced as compared with the case where the outer diameter of the outer cylinder is constant in the axial direction. In addition, the removal force of the press-fitted outer cylinder can be ensured, and the stability against input in the direction perpendicular to the shaft is excellent. In addition, the rubber annular ribs provide excellent sealing performance against water and dust.

[Brief description of drawings]

FIG. 1 is a side view of a vibration isolator according to one embodiment of the present invention,

Fig. 2 is a vertical sectional view of the vibration isolator (a sectional view taken along the line II-II in Fig. 3).

Figure 3 is a bottom view of the vibration isolator,

Fig. 4 is a cross-sectional view of the vibration isolator during manufacturing (before the outer cylinder is drawn).

FIG. 5 is a longitudinal sectional view of the vibration isolator in an assembled state.

[Best mode for carrying out the invention]

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

The anti-vibration device of the present embodiment is a body mount for supporting an underbody member such as an automobile suspension in a vibration-proof manner with respect to the body, and is arranged concentrically around the inner cylinder 10. An outer cylinder 12 and a rubber elastic body 14 interposed between the inner cylinder 10 and the outer cylinder 12 and connecting the two. In this example, the inner cylinder 10 is a member that is mounted to the body via the mounting member 1 and is fastened and fixed to the mounting member 1 by a bolt 2 that penetrates the inner side. The outer cylinder 12 is fixed to the cylindrical holder 4 of the suspension member connected to the suspension member by being press-fitted from above.

Two diametrically opposed portions of the rubber elastic body 14 are formed with burrs 16 and 16. As a result, when a low load is applied to the body mount that oscillates in the direction crossing the diametrical section 16 in the diametric direction, the bulging section 16 bends, and the rubber elastic body is formed around the inner cylinder 10. 14 exerts soft radius characteristics and contributes to vibration isolation. Also, in the direction perpendicular to the above transverse direction, In other words, a rigid radius characteristic can be exhibited to withstand high-load vibration, and thus the spring characteristic is given a different direction.

The outer cylinder 12 has a flange 18 extending radially outward at an upper end thereof, and a stopper rubber 20 which exerts a stopper function between the mounting member 1 and the stopper rubber 20 is provided on the upper surface of the flange 18. It is made of rubber connected to the body 14. Further, on the lower surface of the flange 18, a plate-shaped contact rubber 22 which comes into contact with the flange portion 5 at the upper end of the holder 4 is formed of rubber continuous from the rubber pad 20. A plurality of axial ribs 24, 24... Slightly projecting outward in the radial direction and extending in the axial direction are provided on the outer peripheral surface of the outer cylinder 12 at predetermined intervals in the circumferential direction. As shown in FIG. 3, in this embodiment, six directional ribs 24 are evenly arranged in the circumferential direction.

Also, as shown in FIGS. 1 and 2, the axial rib 24 extends axially downward from the end (ie, the upper end) on the flange 18 side, and is located within a press-fit range 30 into the holder 4. It terminates at the approximate center in the axial direction. The length of the axial rib 24 is not particularly limited, but is preferably terminated so as not to intersect with the annular rib 26 described later. Specifically, the press-fit range 30 of the axial rib 24 4 and the length 25 from the upper end should be set within the range of 2/3 to 1/3 of the axial length of the press-fit range 30. Is preferred. In the present embodiment, the length of the axial ribs 24 is set to the same value for six ribs, but may be set to different values.

In this embodiment, the outer cylinder 12 is made of a metal material such as iron, and its peripheral wall is radially inward so that the compression amount differs between the portion where the axial ribs 24 are arranged and the other portions. The plurality of axial ribs 24 are formed on the outer peripheral surface of the outer cylinder by being compressed. That is, the compression amount is set small in the portion where the axial ribs 24 are provided, and large in the other portions.

A single rubber annular rib 26 extending around the entire circumference in the circumferential direction is fixed to the outer peripheral surface of the outer cylinder 12. The annular rib 26 is provided at the end on the opposite side of the flange (opposite to the flange 18), that is, at the lower end of the outer cylinder 12 in the press-fitting range 30. Has been. The projecting height of the annular rib 26 outward in the radial direction is set to be slightly larger than the projecting height of the axial rib 24 because it is compressed and assembled by the inner peripheral surface of the holder 4 at the time of press-fitting. I have. Further, the annular rib 26 is formed to have an inclined surface 26A on the lower end side in consideration of insertability at the time of press-fitting.

′ When manufacturing the vibration isolator of the present embodiment, as shown in FIG. 4, the outer cylinder 12 is formed into a cylindrical shape having a constant outer diameter in the axial direction (this outer cylinder 12 is formed in advance). The rubber elastic body 14 is vulcanized and molded using a rubber mold (not shown) between the inner cylinder 10 and the inner cylinder 10. At this time, an annular rib 26 is formed on the outer peripheral surface of the outer cylinder at the end opposite to the flange side. Next, in order to remove residual strain due to shrinkage after vulcanization in the rubber elastic body 14, a so-called drawing is performed to compress the outer cylinder 12 inward in the radial direction. At the time of drawing, the outer peripheral surface of the outer cylinder 12 is fixed using a die (not shown) so that the drawing ratio (compression amount) of the other portion is larger than that of the portion where the axial ribs 24 are arranged. By pressing inward and compressively deforming in the radial direction, the axial ribs 24 are formed.

The axial ribs 24 may be formed before the rubber elastic body 14 is vulcanized. However, when the axial ribs 24 are formed after the vulcanization molding as described above, the rubber elasticity may be reduced. When the body 14 is vulcanized and formed, the outer cylinder 12 has a cylindrical shape with a constant outer diameter, so that there is an advantage that vulcanization and molding are easy.

In FIG. 5, reference numeral 8 denotes a stopper for restricting excessive displacement of the inner cylinder 10 upward, and includes a ring-shaped reinforcing bracket 8A and a rubber 8B integrally formed on the lower surface thereof. It is composed of

In the body mount according to the present embodiment as described above, when press-fitted into the holder 4 as shown in FIG. 5, the flange 18 side with the axial rib 24 becomes a press-fit portion of a rigid body, and the annular rib 26 is provided. The non-flange side is a press-fitting part made of rubber.

As a result, the contact area between the rigid body and the inner peripheral surface of the holder 4 is reduced as compared with the case where the outer cylinder has a constant outer diameter, and the force required for press-fitting is reduced and the mounting workability is improved. be able to. In particular, an axial rib 24 is provided on the flange 18 side. Therefore, the press-fitting workability is further improved as compared with the case where the axial ribs 24 are provided on the side opposite to the flange to be press-fitted first. Further, since the press-fitting portion of the rigid body is constituted by the axial ribs 24 instead of the circumferential ribs, the mounting workability is excellent. In other words, when circumferential ribs are provided in multiple stages instead of the axial ribs 24, when press-fitting the holder, the peak of the press-in force is generated every time the tire crosses over each circumferential rib, and the fluctuation of the press-in force is large. The press-fitting workability is impaired, but the axial rib 24 does not cause such a problem.

Further, the press-fit outer cylinder 12 is firmly held in the axial ribs 24 by the contact of the rigid bodies with the inner peripheral surface of the holder 4 at a high contact pressure. Can be sufficiently secured.

Further, the end on the side opposite to the flange is held by the contact between the annular rib 26 and the inner peripheral surface of the holder 4, so that stability against input in a direction perpendicular to the axis is also ensured. That is, when the shaft is held only by the axial ribs 24, particularly when the length of the axial ribs 24 is short, the axis of the inner cylinder 10 is inclined with respect to the axis of the outer cylinder 12. However, the lower rib 26 along with the upper axial rib 24 also supports the inner peripheral surface of the holder 4, so that such a twisting direction is likely to occur. Can be suppressed.

Further, when water or dust enters from the lower end of the outer cylinder 12 to the space between the outer cylinder 12 and the holder 4, the intrusion can be prevented by the annular rib 26. Further, since only one annular rib 26 at the lower end is provided on the outer peripheral surface of the outer cylinder 12, a rubber film having a multistage annular rib is formed on the outer peripheral surface of the outer cylinder as in the conventional case described above. Compared to the case where it is performed, the moldability is excellent and the productivity is improved.

In the above embodiment, the outer cylinder 12 made of metal is used, but the outer cylinder may be made of a resin material such as polyamide 66. When a resin material is used, the axial ribs 24 can be formed during the injection molding of the outer cylinder.

[Industrial applicability]

ADVANTAGE OF THE INVENTION According to the vibration isolator of this invention, the mounting workability of an outer cylinder to a cylindrical holder can be improved. It is also excellent in stability against input in the direction perpendicular to the axis. Also, in particular, while the axial lip is formed of a rigid lip, the annular lip is formed of a rubber lip, so that the detaching force from the holder can be secured while improving the mounting workability. Excellent sealing performance against dust and dust.

Claims

The scope of the claims

1. An inner cylinder, an outer cylinder surrounding the inner cylinder, and a rubber elastic body interposed between the inner cylinder and the outer cylinder to couple the two cylinders to each other; A plurality of axial lips arranged at intervals in the circumferential direction and extending in the axial direction are provided, and an annular lip extending in the circumferential direction is provided at one axial end of the outer cylinder. Anti-vibration device.

2. The outer cylinder has a flange extending radially outward at one axial end thereof, and the annular rib is provided at an end of the outer cylinder opposite to the flange, and the axial rib is provided on the flange side. 2. The vibration isolator according to claim 1, wherein the vibration isolator extends in an axial direction from an end and does not cross the annular rib.

3. The vibration damping device according to claim 2, wherein the outer cylinder is press-fitted into a cylindrical holder, and the axial rib terminates at a substantially axial center of a press-fitting range of the holder.

4. The vibration isolator according to claim 1, wherein the axial rib is a rigid lip.

5. The outer cylinder is made of a metal material, and its peripheral wall is radially inwardly compressed so that the amount of compression is different between the portion where the axial ribs are arranged and the other portion, thereby obtaining the plurality of axial directions. 5. The anti-vibration device according to claim 4, wherein a lip is provided.

6. The vibration isolator according to claim 1, wherein the annular rib is a rubber rib fixed to an outer peripheral surface of the outer cylinder.