JPH0664005A - Injection mold - Google Patents

Abstract

(57) [Summary] [Purpose] To facilitate the release of a decorated product. [Structure] By applying an embossing process equivalent to the embossing process applied to the molding surface 2 of the fixed mold 1 to the molding surface 6 of the movable mold 5, a strong release resistance generated on these embossing surfaces at the time of mold release. The mold is offset so that the molded product can be easily released from the fixed mold 1 without being left.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal mold for injection molding, and more particularly, it is characterized in that a decorated product can be easily released from the mold. For molds.

[0002]

2. Description of the Related Art For example, in an instrument panel W of an automobile, as shown in FIG. 2, a surface called "decoration" such as leather or wood pattern is formed on a surface a which forms an outer surface of a box. Processing is applied.

[0003] This type of decoration forming processing method includes a method of directly processing by the mold itself and a method of secondary processing after the mold is formed. In terms of the size and quantity of the formed product, the former molding process is generally adopted for the decoration process.

However, since the surface of the molded product is decorated with a mold, from the standpoint of mold release, it has the same effect as providing a kind of undercut portion on the molded product. When embossing is applied to the molding surface of the fixed mold to decorate the outer surface of the molded product, the mold release resistance becomes extremely large, and the molded product remains on the fixed mold side at the time of mold release. The phenomenon of "fixed mold release" occurs, which causes scratches on the molded product, causes clogging of the injection port, or defective molding due to defective gas release in the cavity. Various problems arise.

Of course, in order to eliminate such a "fixed mold release", many undercut parts are provided on the back surface of the molded product, and the resistance applied to these parts at the time of mold release is used to mold from the fixed mold. It is considered possible to release the product from the mold, but it is said that the undercut part should not be provided as much as possible in the product design, but providing a wasteful undercut part complicates the mold device by mischief. Not only does it cause inconvenience, but also causes a failure during molding.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to:
It is an object of the present invention to provide a simple injection-molding die capable of easily releasing a decorated molded product without causing “fixed mold release”.

[0007]

That is, according to the present invention, as an injection-molding die for achieving the above-mentioned problems, a mold surface of a movable die is separated from a molding surface of a fixed die by a graining process. It is designed to be embossed so as to produce a mold release resistance similar to the mold resistance.

[0008]

EXAMPLES Examples of the present invention will be described below. FIG. 1 shows an injection molding die for forming an instrument panel of an automobile, which is an embodiment of the present invention.

In the drawing, reference numeral 1 is a fixed mold, and a molding surface 2 of this female mold cavity for forming an instrument panel W as a molded product is provided with a decoration process to be formed on the surface of the instrument panel W, that is, The textured surface 3 according to the leather, the grain pattern, etc. is formed by a surface processing technique such as chemical corrosion, photoetching or electroforming.

On the other hand, the movable mold shown by the reference numeral 5 is made to correspond to the fixed mold 1 by the instrument panel W.
A molding surface 6 of a male cavity for forming
This surface 6 also has a textured surface 7 with an appropriate surface processing technique.
Are formed.

The embossing process applied to the molding surface 6 on the movable mold 5 side opposes the mold release resistance generated by the embossing process applied to the fixed mold 1 side, in other words, the embossing on the fixed mold 1 side. A mold release resistance corresponding to the mold release resistance generated by the processing 3 is applied to the movable mold 5.

Therefore, the embossing applied here does not have to be in accordance with a special pattern, but rather, from the viewpoint of making the resistances at the time of mold release uniform, the fixed mold 1 is used.
The surface of the side molding surface 2 is embossed with an area equivalent to the surface area of the molding surface 6, or the molding surface 6 of the movable mold 5 has a large mold release resistance comparable to that of the fixed mold 1. It is desirable to apply the embossing to the molding surface 6 on the movable mold 5 side, and further, on the molding surface 2y on the fixed mold 1 side, the molding surface 2y in a direction orthogonal to the mold dividing surface PL. The embossing that is performed, that is, the embossing that produces the same degree of release resistance as the embossing on the fixed mold 1 side where the mold release resistance is the largest, is performed on the movable mold 5 side. Surface PL
It is desirable to apply it to the molding surface 6y which is orthogonal to.

Reference numeral 8 in the drawing denotes an eject pin provided on the movable mold 5 side, and 9 denotes an undercut portion provided on the movable mold 5 for forming the instrument panel mounting piece b. .

In the apparatus thus constructed, when the movable mold 5 is retracted so as to take out the molded product formed on the joint surface of the two molds, that is, the instrument panel W, the textured work is fixed. The strong mold release resistance generated on the molding surface 2 on the mold 1 side is offset by the mold release resistance generated on the molding surface 6 on the movable mold 5 side, which has also been textured, and the instrument panel W Can be easily released without being held by the fixed mold 1.

Although the present invention has been described with reference to the injection molding mold for molding an automobile instrument panel, the present invention can be applied to other molds for decorating the outer surface of a molded product. It goes without saying that the invention can be applied.

[0016]

As described above, according to the present invention, the movable mold forming surface is subjected to the same embossing as the fixed mold forming surface. It is possible to give a mold release resistance comparable to the mold resistance to the movable mold, and despite the fact that it adopts an extremely simple mold structure, it is easy to make decorated products from fixed molds. The mold can be released from the mold, and various inconveniences caused by the "fixed mold release" can be eliminated.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an injection molding die that constitutes an embodiment of the present invention.

FIG. 2 is a view showing an example of a molded product molded by the same mold.

[Explanation of symbols]

 1 Fixed mold 2 Molding surface 3 Textured surface 5 Movable mold 6 Molding surface 7 Textured surface

Claims (1)

[Claims] 1. An injection method characterized in that the molding surface of a movable mold is subjected to an embossing process which produces a mold release resistance comparable to the mold release resistance produced by the embossing process carried out on the molding surface of a fixed mold. Mold for forming.