JP2004167720A - Manufacturing method for two-layer molded object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a two-layer molded object with the advantages that the number of processes can be reduced and the minimum radius of a design shape is made small without using a high pressure-resistant mold to attach fittings simultaneously with molding. <P>SOLUTION: This manufacturing method comprises a first step for forming a skin 11 from a skin raw material by slush molding, a second step for setting the skin 11 and the fittings 12 at specified positions inside the mold 20, a third step for filling the mold 20 with a resin molding material including a reinforcing material after mold clamping to injection-mold a core 14 and a fourth step for removing the unnecessary part of the outer periphery of the molded object 15 taken out of the mold by mold opening. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a molded product such as an instrument panel for a vehicle having a two-layer structure.
[0002]
[Prior art]
Conventionally, the manufacture of an instrument panel having a two-layer structure has been performed according to the procedure shown in FIG. That is, as shown in FIG. 2A, a core material 1 made of, for example, PP (polypropylene) or PC (polycarbonate) is formed by injection molding or the like. At this time, a large number (for example, about 150) of through-holes 1a for evacuation and a mounting portion 1b for mounting components are simultaneously formed in the core material 1.
Subsequently, as shown in FIG. 2B, the adhesive 2 is applied to the surface of the core material 1 by a spray gun 2a or the like.
In parallel with this, as shown in FIG. 2C, a skin 3 to be provided on the surface of the core material 1 is prepared, and the skin 3 is heated by a heater 4 or the like.
[0003]
Then, as shown in FIG. 2 (D), a heated skin 3 is set on the surface of the core material 1 on which the adhesive 2 is applied, and as shown in FIG. 2 (E), for example, a vacuum chamber The outer skin 3 is brought into close contact with the surface of the core material 1 by performing vacuum evacuation from the back surface of the core material 1 through a through hole 1a provided in the core material 1 by vacuum forming as shown by an arrow A in FIG. Then, the adhesive 2 is dried.
Thereafter, as shown in FIG. 2 (F), the outer periphery of the skin 3 adhered to the surface of the core material 1 is cut as indicated by reference numeral B to remove the excess skin 3a.
[0004]
Finally, as shown in FIG. 2 (G), the mounting component 5 is assembled to a predetermined portion of the core material 1, in the case shown, using the impact wrench 6 or the like.
In this manner, the instrument panel 7 having the two-layer structure including the attachment parts 5 is completed.
[0005]
By the way, in such a method of manufacturing an instrument panel having a two-layer structure, the number of steps is large, and the mounting parts are assembled after the core material 1 and the skin 3 are bonded. And the manufacturing cost increases.
Further, since the skin 3 is brought into close contact with the surface of the core 1 by vacuum forming, it is necessary to form a through hole 1a for evacuation of the core 1, so that the cost of the vacuum forming die is reduced. Will be expensive.
[0006]
Furthermore, since the minimum radius of a design shape that can be formed by vacuum forming is about 1 mm, it may be difficult to realize a desired design.
In addition, since the injection pressure in injection molding of the molding die for the core material 1 is as high as 300 kg / cm ² , for example, it is necessary to cope with high pressure, so that the die cost increases.
[0007]
On the other hand, various methods for producing molded articles having a two-layer structure are known (see Patent Documents 1 to 4).
[0008]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 05-253939 [Patent Document 2]
Japanese Patent Application Laid-Open No. 05-050450 [Patent Document 3]
Japanese Patent Application Laid-Open No. H11-216739 [Patent Document 4]
JP-A-09-150435
[Problems to be solved by the invention]
The technique described in Japanese Patent Application Laid-Open No. 05-253939 (see Patent Document 1) is a method of manufacturing a two-layer molded product by integrally insert-molding a core material into a vacuum-formed skin. However, in this method, since the skin is formed by vacuum forming, the minimum radius of the design shape is similarly restricted, and it is difficult to realize an arbitrary design.
[0010]
Also, the technique described in Japanese Patent Application Laid-Open No. 05-050450 (see Patent Document 2) is a method of manufacturing a two-layer molded product by forming a core material and a skin by injection molding, respectively. While using the mold, a part of the movable mold is slid in the movable direction so that the mold for the core material and the mold for the skin can be switched and used, thereby continuously forming the core material and the skin. It has become. However, in this method, since the core material and the skin are formed by injection molding, a high-pressure compatible mold is required, and the mold cost is increased.
[0011]
In the technique described in Japanese Patent Application Laid-Open No. H11-216739 (see Patent Document 3), a material to be a skin is inserted into a mold, a core material is injection-molded, and the material of the skin is heated to a set temperature. In this case, too, the core material is formed by injection molding, so that a high-pressure-compatible mold is required, which increases the mold cost and increases the surface area of the skin. Since the material needs to be heated, the number of steps increases, and the manufacturing time increases.
[0012]
The technique described in Japanese Patent Application Laid-Open No. 09-150435 (see Patent Document 4) manufactures a two-layer molded product by inserting a slash-molded skin into a mold and integrally molding a core material by injection molding. The method is shown. However, since the skin is formed by slush molding, the radius of the design shape can be reduced, but since the core is similarly formed by injection molding, a high-pressure compatible mold is required, Mold cost will increase.
[0013]
Furthermore, in the above-mentioned manufacturing method (see Patent Documents 1 to 4), when mounting parts are mounted on a two-layer molded product, since both are post-assembled, the number of steps is increased, and the manufacturing time is long. In addition, the manufacturing cost increases.
[0014]
In view of the above, the present invention reduces the number of steps, reduces the minimum radius of the design shape without using a high-pressure-compatible mold, and enables the mounting parts to be assembled at the same time as molding. It is an object of the present invention to provide a method for producing a two-layer molded product.
[0015]
[Means for Solving the Problems]
The object is, according to the present invention, a method for producing a two-layer molded product comprising a core material, and a skin provided on the surface of the core material, and further, mounting components are attached to the core material, A first step of forming a skin by slash molding, a second step of setting the skin and the mounting parts at predetermined positions in the mold, and clamping the mold to mix a reinforcing material into the mold And a fourth step of opening the mold and removing unnecessary portions on the outer periphery of the removed molded article by filling the molded resin material and injecting the core material. This is achieved by a method for producing a two-layer molded article characterized by the following. Preferably, glass is used as the reinforcing material.
[0016]
According to the above configuration, the core is integrally formed with the skin formed by the slush molding, and at the same time, the mounting parts are also insert-molded.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.
FIG. 1 shows an embodiment of a method for manufacturing an instrument panel to be deployed in a vehicle having a two-layer structure to which the method for manufacturing a two-layer molded product according to the present invention is applied.
[0018]
First, in FIG. 1A, as a first step, a skin material 11 is formed by slush molding in which a skin material such as powdered vinyl chloride is charged into a heated mold, melted and gelled. In this case, the design shape of the skin 11 can be provided with a minimum radius of, for example, 0.5 mm or less by slash molding.
[0019]
Subsequently, as shown in FIG. 1B, as a second stage, the skin 11 thus formed is set in a cavity of a mold 20 for molding a two-layer molded product. That is, in the case of the drawing, the skin 11 is set along the cavity surface of the lower die 21 among the lower die 21 and the upper die 22 constituting the die 20.
At the same time, the mounting component 12 is set at the mounting position of the mounting component provided on the upper die 22 of the mold 20.
[0020]
Next, the upper mold 22 is relatively lowered with respect to the lower mold 21 of the mold 20 and clamped. As shown in FIG. A resin molding material is injected from the resin injection section 13 and filled into the cavity of the mold 20 to perform injection molding of the core material 14. In addition, a reinforcing material such as glass is mixed in the resin molding material.
[0021]
Finally, the mold 20 is opened, and the molded product 15 composed of the skin 11 and the core 14 is taken out. As shown in FIG. Cut as indicated by the symbol C to remove the extra skin 11 and the core 14. Thereby, the attachment part 12 is insert-molded, and the instrument panel 10 having a two-layer structure including the skin 11 and the core material 14 is completed.
[0022]
As described above, according to the method of manufacturing the instrument panel 10 having the two-layer structure according to the embodiment of the present invention, the core material 14 is integrally formed with the skin 11 formed by slush molding by injection molding. Therefore, the number of steps is small, and the manufacturing cost is reduced by, for example, about 30%.
[0023]
Furthermore, the minimum radius of the design shape of the skin 11 and the core material 14 depends on the shape of the skin 11 formed by slash molding, and is smaller than the minimum radius (about 1 mm) of the design shape by the conventional vacuum forming. For example, a minimum radius of 0.5 mm or less can be realized. Therefore, an arbitrary design shape can be easily realized.
[0024]
Further, since the mounting component 12 to be assembled to the instrument panel 16 having the two-layer structure is integrally formed simultaneously with the core material 14 by so-called insert molding, post-assembly becomes unnecessary, and the number of steps can be reduced.
[0025]
Further, since the core 14 is formed by injection molding, the injection pressure is relatively low, for example, 3 kg / cm ² . Therefore, the mold 20 does not need to be compatible with high pressure as compared with the case of normal injection molding, and the mold manufacturing cost can be reduced.
[0026]
In addition, since the core material 14 is formed from a resin molding material mixed with a reinforcing material, its strength is enhanced. In order to obtain the same strength, the amount used is small, and the weight of the material is reduced to about 1/3. This can contribute to a reduction in the weight of the automobile.
[0027]
In the above-described embodiment, the case of an instrument panel for an automobile has been described as a two-layer molded product. However, the present invention is not limited to this, and it is apparent that the present invention can be applied to the manufacture of other two-layer molded products. It is.
[0028]
【The invention's effect】
As described above, according to the present invention, the core is integrally formed with the skin formed by slush molding, and at the same time, the mounting parts are also insert-molded. As well as being shortened, manufacturing costs will be reduced. Further, since the core material is formed of a resin molding material mixed with a reinforcing material, the amount of the core material can be reduced to obtain the same strength, and the weight of the core material can be reduced.
[Brief description of the drawings]
FIG. 1 is a process chart sequentially showing the steps of an embodiment of a method for manufacturing a two-layer instrument panel to which the present invention is applied.
FIG. 2 is a process chart sequentially showing steps of an example of a conventional method for manufacturing an instrument panel having a two-layer structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Instrument panel 11 of two-layer structure 11 Skin 12 Mounting part 13 Resin injection part 14 Core material (resin molding material)
15 Molded product 20 Mold 21 Lower mold 22 Upper mold

Claims (2)

A method for manufacturing a two-layer molded product comprising a core material and a skin provided on the surface of the core material, and further, mounting parts are assembled to the core material,
The first step of forming the skin from slush molding from the skin material,
A second step of setting the skin and the attachment parts at predetermined positions in the mold;
The third stage of closing the mold, filling the mold with a resin molding material mixed with a reinforcing material, and injection molding the core material,
Finally, a fourth step of opening the mold and removing unnecessary portions on the outer periphery of the removed molded product,
A method for producing a two-layer molded product, comprising: The method for producing a two-layer molded product, wherein the reinforcing material is glass.

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