JPS63172624A - Two-color molding method - Google Patents

Abstract

PURPOSE:To mold a molded material having a complicated form into two-color molding, by a method wherein two kinds of slide cores shifted independently with each other are provided, the two kinds of the slide cores are shifted in dependently after casting of a first resin, and second resin is cast into a generat ed cavity. CONSTITUTION:An opaque part of a cassette half 20 is molded by a stationary side mold 10 and movable side mold 11 under a state where slide cores 12, 13 are clamped down. The molding is attained by casting opaque resin 21 into a cavity formed between a pair of molds 10, 11 through a gate 24. Then the central slide core 12 is moved upward to the movable side mold 11 and the right and left slide cores 13 are shifted laterally respectively. With this construc tion, a fresh cavity 15 is formed on an intermediate part of a part between the molds 10, 11. Transparent resin 22 is cast into the cavity 15 through a gate 14. Then a molded material of the transparent resin 22 is joined to that of the opaque resin 21 with the resin 22 so as to continue to the molded material of the opaque resin 21.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Application Field 1 The present invention relates to a two-color molding method, in particular a method in which a slide core is disposed movably in a mold and the slide core is moved after injecting a first resin. However, the present invention relates to a 2fΔ molding method in which a second resin is injected into the cavity created by this.

KQ Akira's 11 The present invention provides two types of slide cores that are moved independently of each other, and after the first resin is injected, the two types of slide cores are moved independently, and the cavity created by this is A second resin is injected into the mold, thereby allowing molded products with complex shapes to be molded using a two-color molding method.

K. PRIOR ART Generally, in tape recorders and VTRs, tapes are made into cassettes to facilitate handling of magnetic tapes, and tape cassettes are now being used. A tape cassette is a tape cassette in which magnetic tape is wound around a pair of reels and stored in a cassette casing. The cassette casing is usually constructed by combining a pair of upper and lower halves made of synthetic resin molded bodies. By making a portion of such a tape cassette transparent, it becomes possible to check the internal state or the remaining magnetic tape.

Problems to be Solved by the Invention Akashitsu 1 - When a part of the casing is made transparent, the method of shielding the transparent window part with a separately constructed transparent plate makes it difficult to assemble. Man-hours increase. Therefore, the number of times is 1
1f158-212926 discloses that a cassette casing is molded by a two-color molding method. I!
It is being proposed. According to such a tape cassette, a cassette half having a transparent window can be obtained by molding most of the half with an opaque resin, moving the slide core, and filling the resulting cavity with a transparent resin. It will be done.

The transparent part of such a cassette casing cannot extend as far as the side wall part. This is because the thickness of the window portion and the height of the wall are different, and the side wall is only as thick as the window determined by the stroke of a single sliding core. In other words, the conventional two-color molding method has the disadvantage that the shape of the member to be molded is limited.

The present invention was made in view of these problems, and it is an object of the present invention to provide a method for molding a molded article having a complicated shape by a two-color molding method.

(Means for Solving the Problems) The present invention provides a movable slide core in a mold, moves the slide core after injecting a first resin, and fills a cavity formed by the slide core with a movable slide core. In the method of injecting two resins, two types of slide cores that are moved independently of each other are provided (b. After the first resin is injected, the two types of slide cores are moved independently, The second resin is injected into the cavity created by this.

Therefore, according to the present invention, by changing the moving direction or the movement direction of the slide core of Type 2, ? It becomes possible to mold a molded body having a shape of tJ m by the two-color molding method, and for example, it becomes possible to extend the transparent window to the side wall part of the casing of a tape cassette.

Example] The present invention will be explained below with reference to one embodiment shown in the drawings.

FIG. 1 shows a mold for molding the casing of the tape cassette according to this embodiment, and the mold is composed of a stationary mold 10 and a movable mold 11. The movable mold 11 has a slide core 12 in its center.
are combined, and slide cores 13 that are moved laterally are combined at the left and right lower portions, respectively.

Furthermore, a gate 14 for injecting transparent resin is formed in the stationary mold 10.

When molding a tape force hit casing using such a mold, the fixed side mold 10 and the movable side mold 11 are used to form the cassette half 20 shown in FIG. 2 with the slide cores 12 and 13 closed. Shape the opaque parts.

This molding is accomplished by injecting the opaque resin 21 through the gate 24 into the cavity formed between the pair of molds 10.11. At this time, as shown in FIG. 2, the slide cores 12 and 13 push the opaque resin 21 so that it does not flow to the rear part of the half 20. The opaque portion of the resin 21 will be molded.

After this, the slide core 12.1 is attached to the movable mold 11.
Move 3 each. That is, as shown in FIG. 1B, the center slide core 12 is moved upward, and the left and right slide cores 13 are moved laterally. As a result, a new cavity 15 is formed between the molds 10 and 11 in the middle thereof. Transparent resin 22 is injected into this cavity 15 through the gate 14. Then, with this resin 22, the third M
As shown in FIG. 2, the molded body of transparent resin 22 is joined to the molded body of opaque resin 21 so as to be continuous with the molded body of opaque resin 21, and thus the cassette half 20 can be assembled. After this, as shown in FIG. 1C, the mold 10.11 is
is opened, and thereby the cassette half 20 is taken out.

According to such a molding method, the side wall 23 of the cassette half 20 can also be made of the transparent resin 22h1, especially by the second slide core 13 that moves left and right. The transparent window portion extends to the side wall 23. In other words, the central slide core 12 moves only a distance corresponding to the thickness of the main surface of the cassette half 20, while the slide core 13 forms a cavity with the dimensions necessary to form the side walls 23. By side wall part 2
3 can be made transparent.

According to such a molding method, it is now possible to produce a molded article in a shape that could only be manufactured by rotary molding using the core pack method. In general, the low-criteria method of molding has the drawbacks of long molding cycles, making it unsuitable for mass production, and high cost; however, the method described above makes it possible to eliminate these drawbacks. Become. Additionally, multifunctional core-back two-color molding will be achieved.

Next, a modified method will be explained with reference to FIG.

According to the mold of the above embodiment, the left and right second slide cores 13 are moved in a different direction from the first slide core 12, but according to this modification, the left and right slides The core 13 is adapted to be moved in the same direction as the central slide core 12. By increasing the stroke of the left and right slide cores 13, the side wall 2
I'm trying to get the strokes I need to form a 3.

Therefore, according to this modification, the center core 12 is moved upward, and at the same time, the left and right cores 13 are moved by a stroke corresponding to the height of the side walls 23, so that they hit the stepped portion 16 of the core 12. The cassette half 20 is molded by moving the cassette half 20 to a position where they come into contact with each other, and then injecting transparent resin 22 into the cavity 15. Therefore, with this modification, it is possible to achieve the same effects as those of the above embodiment.

(Effects of the Invention) As described above, the present invention provides two types of slide cores that are moved independently of each other, and moves the two types of slide cores independently in contact with the first resin injected, The second resin is injected into the cavity created by this. Therefore, according to this two-color molding method, it is possible to mold a molded object with a complicated shape by two-color molding. become.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a mold showing a method for molding a cassette half according to an embodiment of the present invention, FIG. 2 is a plan view of the cassette half showing the state of molding of an opaque portion, and FIG. 3 is a transparent portion. FIG. 4 is a plan view of the cassette half showing the state of molding. FIG. In addition, in the symbols used in the drawings, 10... Fixed side mold 11... Movable side mold 12... Slide core (center) 13... Slide core (left and right) 14... Gate 15. ...Cavity 20...Cassette half 21...Opaque resin 22...Transparent resin.

Claims (1)

[Claims] A method in which a slide core is disposed movably in a mold, the slide core is moved after a first resin is injected, and a second resin is injected into a cavity created thereby, which are independent of each other. Two types of slide cores that are moved are provided, and after the first resin is injected, the two types of slide cores are moved independently, and the second resin is injected into the cavity created thereby. A two-color molding method that is characterized by: