JP2002310235A - Vibration isolation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely attach a bolt to a bracket part even when a plastic material is used in the bracket part. SOLUTION: In this vibration isolation device constituted by injection-molding the bracket part 2 to which the bolt 1 is attached by the plastic material to form a rubber 3 integrally in the bracket part 2, a head part seat face 1B of a bolt head part 1A is exposed and the whole head part is inserted into the bracket part 2 when performing injection-molding, the bolt head part 1A consists of an upper part 11 having at least a large surface area and a lower part 12 having a small surface area, and a locking part is formed in either of the upper part 11 and the lower part 12 or/and serration is applied to outer periphery of either of them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration isolator such as an engine mount.

[0002]

2. Description of the Related Art As a conventional vibration isolator, as shown in FIGS. 8 to 10, a rubber 102 is integrally bonded between metal fittings 100 and 101 and attached to one or both of the metal fittings 100 and 101 to an engine or a body. Anti-vibration rubbers provided with bolts 103 are known. Metal fitting 10 for bolt 103
As shown in FIG. 11 to FIG. 13, attachment to the metal fittings 100, 10
Serration 10 is applied to the neck of bolt 103 that contacts
5 or a projection 106 was formed on the neck to caulk this.

[0003]

In order to reduce the weight and the number of processing steps, some of the conventional metal fittings 100 and 101 are made of a plastic material instead of the conventional metal fittings 100 and 101. When the bracket portion (metal fitting 100 or 101) is made of plastic, the plastic is cracked or deformed if a conventional bolt mounting method is adopted.

Accordingly, an object of the present invention is to provide a vibration isolator in which a bolt can be securely attached to a bracket even when a plastic material is used for the bracket.

[0005]

In order to achieve the above-mentioned object, the present invention relates to a vibration isolator in which a bracket to which a bolt is attached is injection-molded from a plastic material, and rubber is integrally molded with the bracket. The head of the bolt is exposed at its head seat surface and the entire head is inserted into the bracket during injection molding, and the bolt head is composed of at least an upper part having a large surface area and a lower part having a small surface area. One of them is provided with a detent portion and / or one of the outer peripheries is serrated. Further, the detent portion and / or the serrations are provided not on the lower periphery but on the upper periphery.

[0006]

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

In FIG. 1, a bracket 2 to which a metal bolt 1 is attached is injection-molded from a plastic material, and a rubber 3 is integrally bonded to the bracket 2, and an inner cylinder 4 is integrally bonded to the rubber 3. Have been. The bolt 1 attached to the bracket portion 2 made of a plastic material is inserted into the bracket portion 2 at the time of injection molding by exposing the bolt head portion 1A with its head seat surface 1B exposed.

FIG. 2 is a plan view of the one shown in FIG. 1, in which bolts 1 are inserted at three places of the bracket portion 2. FIG.

The bolt 1 used in this embodiment is shown in FIG.
And a bolt head 1A having a circular upper portion 11 as shown in FIG.
And a lower part 1 having a detent part (planar square)
2 and the lower surface of the quadrangular lower part 12 has a head seating surface 1
B is formed. The upper part 11 has a larger surface area than the lower part 12, so that the inserted bolt 1 does not come out downward. Further, the lower portion 12 is formed in a square shape, so that the inserted bolt 1 is prevented from rotating.

As means for preventing the bolt 1 from coming off or rotating, means shown in FIGS. 5 to 7 can be considered. In FIG. 5, the lower part 12 is formed in a circular shape and the upper part 11 is formed in a square shape. FIG. 6 shows an example in which both the upper part 11 and the lower part 12 are formed in a square shape. Further, FIG.
Then, serrations are applied to the outer periphery of the upper portion 11 and the upper 11
Both the lower part 12 and the lower part 12 are formed in a circular shape. Such serrations may be applied only to the lower portion 12 or to both the upper portion 11 and the lower portion 12. Further, serrations can be arbitrarily applied to the bolt head 1A having a shape as shown in FIGS.

Regardless of which bolt 1 is used, the head seat surface 1B must be exposed when the bolt head 1A is inserted into the bracket 2. If the head seating surface 1B is not exposed, the resin of the bracket portion 2 will fall due to contact with the mating member.

When manufacturing a vibration-proof rubber as shown in FIGS. 1 and 2, a rubber 3 is preliminarily vulcanized and bonded to the outer periphery of an inner cylinder 4, and the inner cylinder 4 and the rubber 3 are injection-molded. After setting in the mold and setting the bolt 1 in the mold, the plastic material is injected. Pressure is applied to the rubber 3 by the injection pressure of the plastic material. The injection pressure eliminates the need for press-fitting and drawing of rubber into the bracket portion, which has been conventionally performed. When the injected plastic material is cooled and solidified, the rubber 3 is compressed and the bolt 1 is inserted into the bracket portion 2. In this manner, by forming the bracket portion 2 with a plastic material, it is possible to reduce the weight and the number of processing steps.

In addition, the detent and the serrations are located on the upper
1 and not formed in the lower part 12 can be molded neatly without injection of the plastic material on the head seat surface 1B after injection molding. Conversely, head seating surface 1B
When the serration is formed in the lower portion 12 adjacent to the head, the plastic material may protrude from the uneven portion of the serration, and burrs may be generated on the head seat surface 1B.

For example, the mounting side of the engine or the body comes into direct contact with the seating surface 6 of the head seating surface 1B of the bolt 1 without the interposition of a plastic burr portion, thereby enabling metal to metal connection and loosening of the bolt. Does not occur, and the mounting strength is secured.

[0015]

As described above, according to the present invention, the bolt head is exposed at its head seat surface, and the entire head is inserted into the bracket during injection molding.
Since the bolt head is composed of at least an upper part having a large surface area and a lower part having a small surface area, a detent part is formed on one of the upper part and the lower part, and / or serrations are applied to one of the outer circumferences. There is no danger of cracking or deformation of the bracket part consisting of
In addition, the overall weight can be reduced and the number of processing steps can be reduced.
Furthermore, in the case where the detent portion and / or the serration is provided not on the lower outer periphery but on the upper outer periphery, there is no possibility that burrs will be generated on the head seat surface after injection molding, and the mounting strength can be secured.

[Brief description of the drawings]

FIG. 1 is a front view showing a preferred embodiment of the present invention.

FIG. 2 is a plan view of FIG. 1;

FIG. 3 is a front view of the bolt.

FIG. 4 is a bottom view of the bolt.

FIG. 5 is a bottom view showing a modification of the bolt.

FIG. 6 is a bottom view showing another example of a bolt.

FIG. 7 is a front view showing an example in which serrations are applied to a bolt head.

FIG. 8 is a front view showing a conventional vibration isolator.

FIG. 9 is a front view showing another conventional vibration damping device.

FIG. 10 is a front view showing still another conventional vibration damping device.

FIG. 11 is a sectional view showing a conventional bolt mounting example.

FIG. 12 is a sectional view showing still another example of bolt attachment.

FIG. 13 is a cross-sectional view showing a conventional example in which a projection is provided on a bolt for caulking.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bolt 1A Bolt head 1B Head bearing surface 2 Bracket part 3 Rubber 11 Upper part 12 Lower part

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3D035 CA05 3J048 AA01 BA04 EA01

Claims (2)

[Claims] 1. A vibration isolator in which a bracket to which bolts are attached is injection-molded from a plastic material, and rubber is integrally molded with the brackets. At the time of injection molding at the time of injection molding, the bolt head is composed of at least an upper part having a large surface area and a lower part having a small surface area, and a detent part is formed on one of the upper part and the lower part.
And a serration on one of the outer peripheries. 2. The anti-vibration device according to claim 1, wherein the rotation preventing portion and / or the serration are provided not on the lower outer periphery but on the upper outer periphery.