JP3486818B2 - Bush type anti-vibration rubber - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bush-type vibration-isolating rubber having a rigid outer cylinder portion divided into two parts. In particular, the present invention is suitable for a body mount cushion (anti-vibration mount) of front and rear suspension members in an automobile. Here, a body mount cushion will be described as an example, but the present invention is not limited to this. 2. Description of the Related Art FIGS. 1 and 2 show an example of a conventional bush-type anti-vibration rubber used as a body mount cushion. [0004] The rigid inner cylindrical portion 1 and the rigid outer cylindrical portion 3 are connected by an anti-vibration rubber portion 5, and the rigid outer cylindrical portion 3 is divided into a pair of half cylindrical portions 3a, 3a. The half cylinder portions 3a, 3a are separated from each other before press-fitting into the cylindrical holder 9, and the half cylinder portions 3a, 3a approach each other after press-fitting into the cylindrical holder 9. The rigid outer cylindrical portion 3 has a drawn shape so that the upper end side (tip side) is easily inserted, and the lower end side (original end side) is engaged with the lower end of the cylindrical holder 9. Thus, the engagement flange 7 is formed. Here, the vibration-proof rubber is pressed into a cylindrical holder 9 formed integrally with the suspension member (sub-frame) 11 from below, and the rubber vibration-proof rubber is bolted to a bolt 15 protruding from the vehicle body 13. Is inserted into the rigid cylindrical portion 1 made of a vibration-proof rubber, and the nut 19 is inserted through the washer 17.
Into the body 13 and the sub-frame 11
And between them. In the illustrated example, reference numeral 21 denotes a stopper rubber. The vibration-absorbing rubber has an effect of attenuating vibrations such as vertical movement and vertical swing acting on the sub-frame during traveling of the vehicle and transmitting the vibrations to the vehicle body. [0007] However, in the vibration isolating rubber having the above-mentioned structure, a force is applied to the vibration isolating rubber in a downward direction during rebound. For this reason, it was found that relative misalignment occurred between the outer periphery of the outer cylindrical portion 3 and the cylindrical holder 9, and an abnormal noise (squeaking noise) was generated. Note that the vibration-proof rubber at the time of bounce tends to come off upward, but this is prevented by the engagement between the lower end of the cylindrical holder 9 and the flange portion 7 of the rigid outer cylindrical portion 3. In order to prevent this displacement, it is conceivable to provide an engaging projection at the upper end position of the holder on the outer periphery of the outer cylinder and engage the upper end edge of the holder to prevent the displacement. (See Japanese Utility Model Publication No. 57-126649, etc.)
It is necessary to press-fit from the bottom because the outer cylinder portion has a flange portion, and at that time, the press-fitting work into the cylindrical holder becomes difficult due to the presence of the engagement convex portion. Further, since the holder is usually formed by press working and has a large manufacturing dimensional tolerance, it is necessary to form the engaging projection at a higher position in consideration of the tolerance. For this reason, it is difficult to sufficiently prevent the shift movement. [0010] In view of the above, the present invention provides a bush-type anti-vibration rubber capable of improving the workability of press-fitting into a cylindrical holder and further reliably preventing the sliding movement with respect to the cylindrical holder. With the goal. The bush type vibration damping rubber of the present invention solves the above problems by the following constitution. [0012] A rigid body cylindrical portion and a rigid body outer cylinder portion having an engagement flange portion on an original end side are connected by a vibration isolating rubber portion, and the rigid body outer cylinder portion is formed of a pair of half cylinder portions. In a bush-type anti-vibration rubber having a configuration in which the semi-cylindrical portions are separated from each other before being press-fitted into the cylindrical holder, and the semi-cylindrical portions are close to each other after being press-fitted into the cylindrical holder, the rigid outer cylinder part forming a plurality of holes on the peripheral wall of, after press-fitted into the tubular holder, the engagement portion can be formed the anti-vibration rubber portion from the outer cylindrical portion outer peripheral surface exits Ri Sako <br/> from the through hole along with being a, 該迫Ri
The protruding engagement portion engages with the upper edge of the holder and rebounds.
The outer cylinder portion can be prevented from slipping at the time of closing . The operation and effect of the present invention are as follows.
With the configuration as described above, the following operations and effects can be obtained. At the beginning of the press-fitting of the vibration-proof rubber into the holder, the pushing-out force of the vibration-proof rubber part forming the engaging portion is small, and the pushing-out force becomes large at the final stage of the press-fitting. For this reason, the press-fitting workability is improved as compared with the case where the engaging portion is formed from the beginning. Since the engaging portion formed on the outer cylinder portion is a rubber member, it can be absorbed even if the manufacturing dimensional tolerance of the holder is large and can be securely engaged. You can prevent the slip inside. Hereinafter, the present invention will be described in detail with reference to examples. The same parts as those in the above-described example are denoted by the same reference numerals, and all or part of the description thereof is omitted. As in the above-described embodiment, the rigid inner cylindrical portion 1 and the rigid outer cylindrical portion 3 provided with the engaging flange 7 on the lower end side (original end side) are connected by a vibration-proof rubber portion 5. , Rigid outer cylinder 3
Is divided into a pair of half-cylinder portions 3a, 3a, and the half-cylinder portions 3a, 3a are separated from each other before being pressed into the cylindrical holder 9, and the half-cylinder portions 3a, 3a are pressed after being pressed into the cylindrical holder 9. The configuration is such that they are close to each other. Here, the separation distance d between the half-cylinder portions 3a, 3a is 3 to 5 mm when the outer peripheral radius of the half-cylinder portions 3a, 3a is 25 mm. Further, the molding material of the rigid body cylindrical portion 1 and the rigid body outer cylindrical portion 3 is not particularly limited as long as it has a required strength. For example, metal materials such as steel and aluminum, reinforced plastics, and ceramics are arbitrary. The anti-vibration rubber part is formed of natural rubber, ethylene propylene rubber, or the like, and is usually insert-molded by injection, transfer, or the like, using the above-mentioned rigid inner cylinder 1 and rigid outer cylinder 3 as inserts. Up to this point, there is substantially no difference from the conventional example. The shape of the inner cylinder 1 and the outer cylinder 3 are both cylindrical in the illustrated example, but the shape of the outer cylinder may be elliptical, rectangular, or the like. In the above embodiment, in this embodiment, FIGS.
As shown in FIG. 4, a plurality of holes 23 or 23A are formed in the peripheral wall of the metal rigid outer cylindrical portion 3, and as shown in FIG. Mold. Then, as shown in FIG.
After press-fitting, the rubber vibration isolating portion 5 protrudes from the outer peripheral surface of the outer cylindrical portion 3 to form an engaging portion 5a which engages with the upper edge (engagement receiving portion) 9a of the cylindrical holder 9. In the initial stage of the press-fitting, the vibration-proof rubber portion 5 tries to protrude from the outer peripheral surface of the outer cylindrical portion 3, but the outer cylindrical portion 3 is press-fitted into the holder 9 only at the tip portion. There is room for the material to escape, and the power is weak. Thereafter, the pushing force gradually increases, but at that time, the resistance is small and the influence on the press-fitting workability is small because of the dynamic friction state during the press-fitting movement. Since the engaging portion 5a is a rubber member, it can absorb even if the manufacturing dimensional tolerance of the holder 9 is large. Further, the presence of the engagement portion 5a can prevent the outer cylinder portion 3 from being displaced in the holder 9 during rebound. Therefore, it is possible to reduce the generation of abnormal noise while the vehicle is running. In the example shown in FIG. 7, a hole-shaped engagement receiving portion 9b is formed in the holder 9 and a hole 23B for extruding rubber is formed in the outer cylinder portion 3 in correspondence with the hole. Good.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an example of a conventional bush-type anti-vibration rubber. FIG. 2 is a longitudinal sectional view showing a state in which the anti-vibration rubber of FIG. 1 is pressed into a holder. FIG. 4 is a perspective view showing an example of a divided half-cylinder portion of an outer cylinder portion of an anti-vibration rubber in the embodiment. FIG. 4 is a perspective view showing another example. FIG. FIG. 6 is a longitudinal sectional view showing a state in which the vibration isolating rubber of FIG. 5 is pressed into the holder. FIG. 7 is a partial longitudinal sectional view showing a state in which the vibration isolating rubber of another embodiment is pressed into the holder. DESCRIPTION OF SYMBOLS 1 Rigid body cylindrical part 3 Rigid outer cylindrical part 3 a Half cylinder part 5 Anti-vibration rubber part 7 Engagement flange part 9 Cylindrical holder 23, 23A, 23B Through hole for protruding engagement part

Claims (1)

(57) [Claim 1] A rigid body cylindrical portion and a rigid outer cylindrical portion provided with an engagement flange portion on an original end side are connected by a vibration isolating rubber portion, The rigid outer cylinder portion is divided into a pair of half cylinder portions, and the half cylinder portions are separated from each other before being pressed into the cylindrical holder, and the half cylinder portions are close to each other after being pressed into the cylindrical holder. In the bush-type anti-vibration rubber, a plurality of through holes are formed in a peripheral wall of the rigid outer cylindrical portion,
When pressed into the tubular holder, the vibration damping rubber portion from the outer cylindrical portion outer peripheral surface being capable forming the engagement portion out looming from the through hole
With that, the upper edge of該迫Ri out engagement portion is the holder
To prevent slippage of the outer cylinder during rebound.
A bush-type anti-vibration rubber characterized in that it can be stopped .