JPH04201529A - Insert molding - Google Patents

Abstract

PURPOSE:To obtain a highly accurate composite resin insert molded product without any warpages or waviness by providing a protruded annular projection and a recessed annular projection on a resin molding shaft in the vicinity of the external end of insert parts. CONSTITUTION:The inward cooling contraction of a resin molding main body 1 is absorbed at the outside of external end of an insert molding 2 through the deformation of a protruded annular projection 6 and recessed annular projection 7 provided on the main body 1. In this way, a molded product can be obtained which has no any warpages or wavinesses on the upper surface 3 or the outer periphery 4 of the resin molded main body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an insert molded product composed of a resin obtained by injection molding and parts made of different materials.

BACKGROUND OF THE INVENTION In recent years, composite molded parts made of resin and different materials have been widely used for the purpose of reducing the number of parts and assembly man-hours. In order to obtain this composite part, insert molding is usually performed in which parts made of different materials are set in a mold and then injection molded.

An example of the above-mentioned conventional insert molded product made of different materials will be described below with reference to the drawings.

FIG. 2 shows a cross-sectional view of a conventional insert molded product. In FIG. 2, 1 is a resin molded product body. 2 shows an insert part made of different materials to be composite molded. Reference numeral 3 indicates the upper surface of the resin molded product main body 1, and 4 indicates the outer edge of the resin molded product main body 1. 5 is the outer end of the insert part 2.

Regarding the insert molded product configured as above, the product shape after injection molding will be described below.

In an insert molded product manufactured by injection molding, for example, a thin metal part is used as the insert part 2,
This is set in a mold during injection molding of the resin molded product main body 1, resin is injection molded around it, and after cooling, it is taken out as an integral part and completed.

Problems to be Solved by the Invention However, with the above configuration, during insert molding,
The cooling shrinkage that occurs in the resin molded product body 1 causes the insert part 2 to shrink.
This is hindered by the restriction by the outer edge 5 of the outer edge 4, causing the outer edge 4 to warp significantly upward or downward. Further, the upper surface portion 3 cannot ensure flatness and undulations occur.

In view of the above problems, the present invention provides a highly accurate insert molded product by reducing warping and waviness of the resin molded product body during insert molding.

Means for Solving the Problems In order to solve the above-mentioned problems, the insert molded product of the present invention is an insert molded product in which a molded resin material and an insert part made of different materials are arranged in the center. It is characterized in that a convex annular projection and a concave annular projection are provided on the resin molded product body near the end.

Function: With the above-described configuration, the present invention can absorb the cooling shrinkage inward of the resin molded product body during injection molding by deformation of the convex annular projection and the concave annular projection, and the upper surface of the resin molded product body It is possible to obtain a product without warping or waviness at the outer edge.

EXAMPLE Hereinafter, an insert molded product according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of an insert molded product in one embodiment of the present invention. In FIG. 1, 6 is a convex annular projection provided on the resin molded product main body 1, and 7 is a concave annular projection. The other constituent parts are the same as those of the conventional insert molded product shown in FIG. 2, so the same numbers are given and explanations are omitted.

The insert molded product configured as above will be described in detail below.

Usually, the molding shrinkage rate of resin is 5/1000 to 15/10.
00, and if the shrinkage is restrained by the insert part 2, the outer resin part will be greatly deformed, but in the insert molded product shown in FIG. Since they are provided uniformly on the outside of the portion 5, it is possible to absorb all the cooling shrinkage of the resin during insert molding. As a result, the outer edge portion 4 of the main body does not warp and exhibits shrinkage in the same way as when there is no insert component.

Effects of the Invention As described above, the present invention enables cooling shrinkage of the resin on the outside of the insert part to be caused by each uneven annular protrusion in an insert molded product, resulting in a highly accurate composite resin insert without warping or waviness. Molded products can be realized.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an insert molded product according to an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional insert molded product. DESCRIPTION OF SYMBOLS 1... Resin molded product body, 2... Insert part, 5... Outer end, 6... Convex annular projection, 7... ...Concave annular projection. Name of agent: Patent attorney Akira Koebi and 2 others +-4tT%
mbutaakishina se1 F-iririto fy-productday Masubou light g--one convex attack I summer

Claims (1)

[Claims] An insert molded product formed by placing a molded resin material and an insert part made of a different material in the center, characterized in that a convex annular protrusion and a concave annular protrusion are provided on the resin molded product axis near the outer end of the insert part. Insert molded products.