JP3689857B2 - Anti-vibration device manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a vibration isolator used as a bushing device such as a suspension bush of an automobile, an engine mount, a stabilizer link rod, a buffer rod, or the like.
[0002]
[Prior art]
As a conventional device of this type, a device described in Japanese Patent Publication No. 3-53094 is known. As shown in FIG. 6, a split mold (only the lower mold 100 is shown) is prepared, and the inner cylinder 101 and the elastic body 102 are set in a predetermined cavity of the mold. A rod forming cavity 103 and an outer cylinder forming cavity 104 are provided, and a resin material is injected from the injection gate 105 into the cavities 103 and 104. In addition, voids 106 and 107 are formed in the mold portions facing the upper and lower ends of the elastic body 102. When a resin material is fed from the runner 108 and injected into the cavities 103 and 104 from the injection gate 105 with a predetermined pressure (at this time, an upper die (not shown) is attached), the elastic body 102 faces inward, that is, the inner cylinder The portion of the elastic body 102 that protrudes to the left and right by the injected resin pressure enters the gaps 106 and 107 at the same time as it is compressed in the direction of the central axis 101, and the molding material is cured in this state, and the rod and the outer cylinder are molded. Is done. FIG. 7 shows a state where the elastic body 102 has received the injection pressure.
[0003]
[Problems to be solved by the invention]
Since the gaps 106 and 107 in the conventional manufacturing method are in contact with the inner cylinder 101, the contact point A swells as shown by the dotted line in FIG. 6, and the adhesive surface between the elastic body 102 and the inner cylinder 101 is peeled off. There was a risk of damage. The elastic body 102 is usually vulcanized and bonded to the inner cylinder 101.
[0004]
Therefore, an object of the present invention is to provide a method of manufacturing a vibration isolator that prevents the inner cylinder and the elastic body from being peeled off or damaged when the outer cylinder is molded from a resin material.
[0005]
[Means for Solving the Problems]
In order to achieve the above-described object, the present invention is to prevent the outer cylinder from being molded by setting an outer cylinder provided with an elastic body in an injection mold and injecting a resin material on the outer circumference of the elastic body. In the vibration device manufacturing method, a gap portion is formed at a position facing the upper and lower end surfaces of the elastic body of the mold and spaced from the inner cylinder , and a molding material is injected from the injection gate into the cavity so that the elastic body is molded by resin pressure. It is made to compress and escape into the gap .
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below with reference to the drawings.
[0007]
In the embodiment shown in FIG. 1, reference numeral 1 denotes a molding die. A molding die 1 in which an elastic body 3 is provided on the outer periphery of the inner cylinder 2 is set, and a resin material is injected into the cavities 4 and 5. Shows the state. Gap portions 6 and 7 are formed at positions spaced from the inner cylinder 2 facing the upper and lower end surfaces of the elastic body 3 of the molding die 1. Reference numeral 8 denotes an injection gate. The resin material injected to the outer periphery of the elastic body 3 is solidified to form an outer cylinder.
[0008]
When the molding material is injected from the injection gate 8 into the cavities 4 and 5, the elastic body 3 can be pre-compressed by the molding resin pressure, and shrinkage due to sink marks or the like of the resin main body can be offset. Further, the elastic body 3 compressed by the resin pressure escapes into the gap portions 6 and 7, and the fatigue durability against the movement of the elastic body 3 in the direction perpendicular to the cylindrical axis can be improved. Furthermore, the elastic body 3 compressed by the resin pressure escapes into the gap portions 6 and 7, and an excessive load is not applied to the bonding portion between the inner cylinder 2 and the elastic body 3, and the two are peeled off or damaged. There is no fear.
[0009]
In the second embodiment shown in FIG. 2, the upper and lower end surfaces of the elastic body 3 have constricted portions 3A and 3B, and the mold 1 facing the constricted portions 3A and 3B Gap portions 6 and 7 are provided. In the case of having the constricted portions 3A and 3B in this way, it is possible to prevent the elastic body 3 from being greatly strained when the elastic body 3 is compressed by resin pressure.
[0010]
FIG. 3 is a diagram showing an action state of the resin pressure in the embodiment shown in FIG. 1, and when the elastic body 3 is compressed by the resin pressure, the upper and lower end surfaces of the elastic body 3 escape into the gaps 6 and 7. Show. Also in this embodiment, since the gap portions 6 and 7 are formed at positions separated from the inner cylinder 2, an excessive load (shearing force) is applied to the portion A on the upper and lower end surfaces of the bonding portion between the inner cylinder 2 and the elastic body 3. ) Is not applied.
[0011]
FIG. 4 shows an example in which the shape of the constricted portion 3A of the elastic body 3 is changed, and is a diagram showing a deformed state when the resin pressure is applied.
[0012]
FIG. 5 shows a state before the elastic body 3 of FIG. 4 is subjected to the resin pressure. A central portion of the surface facing the cavity 4 protrudes, and both ends form a recess 3 </ b> C that is recessed inward. The central protruding portion of the elastic body 3 is compressed by resin pressure and straightens as shown in FIG. Since the central projecting portion of the elastic body 3 is pre-compressed by the pressure at the time of injection, the distortion is small with respect to deformation and the durability of the elastic body 3 is improved.
[0013]
【The invention's effect】
As described above, according to the present invention, the gap is formed at a position facing the upper and lower end surfaces of the elastic body of the mold and spaced apart from the inner cylinder , and the molding material is injected from the injection gate into the cavity. molding since so as to be compressed by the resin pressure Nigekoma into the gap portion, or the adhesive peeling the inner cylinder and the elastic body, a possibility is that Ku or damaged. In addition, pre-compression is applied to the elastic body by the resin pressure, and the shrinkage due to sink marks etc. of the molded resin main body can be offset, and the fatigue resistance against the movement of the elastic body in the direction perpendicular to the inner cylinder axis Can also be improved. In addition, in the case where the upper and lower end surfaces of the elastic body have portions that are constricted inward, it is possible to prevent the elastic body from being greatly strained by the resin pressure.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a first embodiment.
FIG. 2 is a cross-sectional view showing a second embodiment.
FIG. 3 is a sectional view showing a resin pressure acting state in the first embodiment.
FIG. 4 is a cross-sectional view of a modification when a resin pressure is applied.
5 is a cross-sectional view of the elastic body 3 in FIG. 4 before receiving a resin pressure.
FIG. 6 is a cross-sectional view showing a conventional example.
FIG. 7 is a cross-sectional view at the time of resin pressure action in a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Molding die 2 Inner cylinder 3 Elastic body 3A, 3B Constricted part 4, 5 Cavity 6, 7 Gap part

Claims (2)

In the manufacturing method of the vibration isolator, in which an elastic body is provided on the outer periphery of the inner cylinder is set in an injection mold, and a resin material is injected on the outer periphery of the elastic body to mold the outer cylinder.
Opposing the upper and lower end surfaces of the elastic body of the mold, forming a gap at a position away from the inner cylinder ,
A method for manufacturing an anti-vibration device, comprising: injecting a molding material from an injection gate into a cavity, compressing an elastic body by molding resin pressure, and allowing the elastic body to escape into a gap portion . Have a portion where the lower end surface is constricted inward on the elastic member,
2. The method for manufacturing a vibration isolator according to claim 1 , wherein the gap portion is provided in a portion of the mold facing the constricted portion .

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