JP2956876B2 - Vacuum molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum molded product obtained by attaching a synthetic resin sheet to a base material and integrally maintaining the shape of the outer surface of the product and the shape of the back surface thereof.

[0002]

2. Description of the Related Art Conventionally, for example, as shown in FIG. 5, a base material 51 molded by injection molding is used for interior parts of automobiles to provide a soft feel and to improve appearance. As a material, a vacuum molded product is used in which the base material 51 and the synthetic resin sheet 52 in which the cushion layer 53 and the skin layer 54 are bonded to each other are formed into a product shape by vacuum molding.

[0003] Usually, the surface on the side where the synthetic resin sheet 52 is attached becomes the product appearance surface, and the opposite substrate 51
Other components are often coupled to the back surface on the side. For this reason, a part of the back surface is a reference surface when other components are mounted.

[0004]

Therefore, the thickness of the base material 51 cannot be made uniform uniformly due to the requirement from the shape on the external appearance of the product and the requirement from the shape on the back side of the substrate 51. It may be partially thick or thin.

In particular, in the thick portion 51a of the base material 51, as shown in FIG. 3, sinks s are easily generated due to molding shrinkage during injection molding. When vacuum forming is performed on the material, there is a problem that a dent d is generated on the external surface of the product, resulting in poor external appearance.

In order to prevent sink marks, for example, Japanese Unexamined Patent Publication No. 3-286814 discloses a method of injecting gas into a thick portion to make the inside of the thick portion hollow.
In such a gas injection system, various new problems such as gas injection timing, gas pressure control, gas injection position, and attachment of additional facilities occur. Therefore, there is a problem that a large amount of cost is required and the equipment becomes large.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention relates to a method of integrating a synthetic resin sheet, in which a skin layer and a cushion layer are bonded, with a base material by vacuum forming, the method comprising: And a projection whose tip is substantially the same as the surface to which the synthetic resin sheet is attached.

[0008]

By providing a projection on the surface of the base material to which the synthetic resin sheet is attached, the sink in the thickness direction is eliminated, and the outer surface of the product and the back surface of the base material on the opposite side are also desired. Keep in shape.

Further, in order to form a projection on the base material, an inverted shape of the projection is engraved in a mold on the corresponding side of the injection mold by, for example, electric discharge machining.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a vacuum-formed product according to an embodiment of the present invention. 1A and 1B show a first embodiment of a substrate according to the present invention, in which FIG. 1A is a longitudinal sectional view and FIG.
Is a cross-sectional view taken along line XX of (A), FIG. 2 shows a vacuum-formed product,
(A) is a longitudinal sectional view, and (B) is a sectional view taken along line YY of (A).

In a vacuum molded product frequently used for interior parts of automobiles, a substrate 2 as shown in FIG. 1 is set in a vacuum mold (not shown), and a synthetic resin sheet 3 as shown in FIG. Then, the substrate 2 and the synthetic resin sheet 3 are integrated and manufactured by vacuuming with a vacuum mold.

The base material 2 is formed by injection molding, for example, an ABS resin or a polyolefin resin such as polyethylene or polypropylene.
The cushion layer 4 is formed by bonding a skin layer 5 to a cushion layer 4 made of a foam material. For example, the cushion layer 4 is formed by a polyolefin foam material, and the skin layer 5 is formed by a polyvinyl chloride (PVC) or polyolefin resin. Molding.

When the vacuum molded article 1 as shown in FIG. 2 is formed, the skin layer 5 side of the base material 2 becomes the outer appearance side of the product, and it is necessary to avoid poor appearance which may cause deterioration of appearance.

At this time, when the back surface of the thick portion 2a of the base material 2 serves as a reference surface b for mounting other parts, it is necessary to accurately form the shape of the reference surface b. There is.

Therefore, in the first embodiment of the present invention, a comb-shaped projection as shown in FIG. 1 is provided on a thick portion 2a of the base material 2 where the shape of the reference surface b on the back surface is required. t,... were formed.

As shown in FIG. 1B, the surface of the comb-shaped projections t, to which the synthetic resin sheet 3 is attached, has an uneven shape. 3 is approximately the same as the surface to which the projections 3 are attached, and the thickness and interval at the tip of the projection t are approximately equal to the thickness of the synthetic resin sheet 3 around the base 2 or the projection t after vacuum forming. . This is to prevent the uneven shape of the protrusion t from appearing on the external appearance of the product when the synthetic resin sheet 3 is attached by vacuum forming.

The comb-shaped projections t,... Are formed, for example, by injection machining into a female mold of an injection mold (a mold having a cavity surface on the product shape side) by electric discharge machining or the like.
The reverse shape is engraved and molded during injection molding.

The reference surface b of the substrate 2 and the protrusions t,
.. Are formed between them to increase the effect of vacuum evacuation and, when the synthetic resin sheet 3 is adhered, the space between the projections t and the external space are formed by the through holes. The air is communicated to prevent air from being trapped in the space between the protrusions t.

By the way, the shape of the protrusion t in the present invention is not limited to the comb-like shape as described above, but also a large number of pin-shaped protrusions t in the form of a prism or a column as shown in the second embodiment of FIG. ,
Alternatively, they may be formed in a lattice as shown in the third embodiment of FIG.

When vacuum forming is performed on the substrate 2 as described above, since no sink marks are generated on the product-shaped surface side of the substrate 2, no dent is generated on the outer surface of the skin layer 5.
The shape of the reference surface b on the back surface can be made accurate. That is, the external shape of the product is not impaired, and the degree of freedom in mounting components on the reference surface b is increased.

In the case of the first embodiment, the interval between the comb-shaped projections t is set to be approximately the same as the thickness of the base material 2 so that the synthetic resin sheet 3 is not sagged when the synthetic resin sheet 3 is attached. It is convenient.

[0022]

As described above, the vacuum molded article of the present invention is a vacuum molded article in which a substrate and a synthetic resin sheet are integrated.
The thick part of the base material is provided with a protrusion whose tip is almost the same as the surface on which the synthetic resin sheet is to be attached. The regular shape can be maintained on both the synthetic resin sheet and the back surface of the base material. Therefore, not only does the appearance quality not deteriorate, but also the degree of freedom in mounting parts increases, and a high value-added vacuum molded product can be provided. Further, even if a gas injection mechanism or the like is not used in injection molding, sink does not occur, and there is no need to add cost to the mold apparatus.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of a substrate according to a vacuum molded product,
(A) is a longitudinal sectional view, (B) is a sectional view taken along line XX of (A).

FIGS. 2A and 2B show a vacuum-formed product according to the first embodiment, wherein FIG. 2A is a longitudinal sectional view, and FIG. 2B is a sectional view taken along line YY of FIG.

3A and 3B are explanatory views showing a second embodiment of the base material, wherein FIG. 3A is a longitudinal sectional view, and FIG. 3B is a partial view of FIG.

4A and 4B are explanatory views showing a third embodiment of the base material, wherein FIG. 4A is a longitudinal sectional view, and FIG. 4B is a sectional view taken along line XX of FIG.

FIG. 5 is a conventional view of a vacuum molded product.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum molded product 2 Base material 2a Thick part 3 Synthetic resin sheet 4 Cushion layer 5 Skin layer t Projection

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁶ , DB name) B29C 45/00-45/84 B29C 51/00-51/46 B29C 63/00-63/48

Claims (1)

(57) [Claims] 1. A vacuum-molded product in which a synthetic resin sheet in which a skin layer and a cushion layer are bonded to each other is integrated with a substrate by vacuum molding. A vacuum formed product having a projection substantially identical to the surface.