JPH0734657Y2 - Two-color mold equipment - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is a molded product obtained by sequentially injecting a primary injection material and a secondary injection material into a cavity formed between a pair of opposing molds. The present invention relates to a two-color molding die device for molding.

[Conventional technology]

Conventionally, for example, when manufacturing an audio cassette half composed of two colors, that is, an audio cassette half having a structure in which a transparent window is fitted inside an opaque (colored) half frame body, A movable mold body is installed in a part of the mold so as to be movable in the mold release direction, and when the primary injection material is filled, the female movable mold body is made to project in the male mold direction to fill the secondary injection material. Is filled with the primary injection material in a state where the space for use is closed, and then, when the secondary injection material is filled, the movable mold body is retracted to form a space for filling the secondary injection material. A method of filling a secondary injection material in a space to form a two-color molded article, that is, a so-called core-back two-color molding method is used.

[Problems to be solved by the device]

However, in the conventional mold for performing the two-color molding method of the core back method, a movable mold body movably provided in a part of the female mold and a female mold around the movable mold body are provided. If a lubricating oil is interposed between the movable mold body and the female mold, the lubricating oil cannot be used because the lubricant mixes in the product and causes a product defect. There is a problem that is likely to occur.

In order to eliminate this galling problem, it is necessary to make a large clearance between the movable mold body and the female mold around it.In this way, the injection material flows into this clearance and burrs are generated. There is a problem of inviting.

The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent the galling between the movable mold body and the mold around the movable mold body and to smoothly move the movable mold body.
Moreover, it is an object of the present invention to provide a two-color molding die device capable of preventing burr generation.

[Means for Solving the Problems]

In order to achieve the above object, the present invention provides a part of a mold,
A movable mold body that forms a space for filling the secondary injection material is movably provided in the mold release direction of the molded product, and is between the movable mold body and a mold surrounding the movable mold body. Provided with a friction reducing member composed of a plurality of steel balls, steel rollers or steel rings that are fixed to one side of the movable mold and the mold and slidably point-contacted or line-contacted to the other side. Is.

[Action]

In the two-color molding die device of the present invention, when the movable mold body provided in a part of the mold moves in the mold releasing direction,
A plurality of steel balls provided between the movable mold body and a mold surrounding the movable mold body are moved by being brought into point contact with the inner surface of the mold while being fixed to the movable mold body. The mold body is accurately positioned with respect to the mold, and the contact area is reduced, which reduces the frictional force generated between the movable mold body and the mold, and prevents galling between the two. As a result, smooth movement of the movable mold body is realized. The same applies when the steel ball is fixed to the mold, and the same applies when a steel roller or a steel ring is used instead of the steel ball.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In these drawings, reference numeral 1 is a fixed mold plate, and this fixed mold plate 1 is attached to a fixed mounting plate 3 via a runner stripper 2. A movable mold plate 4 is movably provided so as to face the fixed mold plate 1, and the movable mold plate 4 includes the first, second and third movable receiving plates 5, 6, 7 and a spacer block ( It is attached to the movable mounting plate 8 via (not shown). Engraved surfaces 1a and 4a for forming the outer surface and the inner surface of the cassette half are formed on the facing surfaces of the template plates 1 and 4, respectively.

The core back assembly 9 penetrates through the movable mold plate 4, the first and second movable receiving plates 5 and 6, and inside thereof, a core back assembly 9 is formed in the releasing direction of the cassette half (molded product) (see FIG. 1 and FIG. It is provided so as to be movable in the vertical direction in FIG. The core back assembly 9 is composed of a movable mold body 10 for molding the window of the cassette half, and a movable receiver 11 for supporting the movable mold body 10. A mounting groove 10a is formed on the outer periphery of the upper portion of the movable mold body 10, and a large number of steel balls (friction reducing members) 12 are mounted in the mounting groove 10a.
The movable receiver 11 of the core back assembly 9 is connected to a piston rod 13a of a hydraulic cylinder 13 arranged inside the third movable receiving plate 7, and oil passages are provided at both ends of the hydraulic cylinder 13. 7a and 7b have been contacted. When the die is closed, the piston rod 13a of the hydraulic cylinder 13 is moved forward to bring the tip surface of the movable die body 10 into close contact with the fixed die plate 1 (see FIG. 1). By moving the piston rod 13a backward, the movable mold body 1
The front end surface of 0 is retracted to be flush with the engraving surface 4a of the movable template 4 (see FIG. 2).

A pair of locate rings 14 and 15 are attached to the fixed mounting plate 3, and the fixed mounting plate 3 and the runner stripper 2 are attached.
Sprue bushes 16 and 17 are inserted through and. The sprue bush 16, the fixed mold plate 1, and the movable mold plate 4 are each filled with a primary injection material (opaque).
A primary injection material passage 18 for injecting from a portion corresponding to the outer surface of the cassette half is formed in a space (cavity) formed between the mold plates 1 and 4. Further, the sprue bush 17 and the fixed mold plate 1 are each formed with a secondary injection material passage 19 for injecting the secondary injection material into the gap from a portion corresponding to the surface of the window portion of the cassette half. ing.

Further, between the third movable receiving plate 7 and the movable mounting plate 8, the first and second projecting plates 20 and 21 are arranged in the mold releasing direction (vertical direction in FIGS. 1 and 2). The first and second projecting plates 20 and 21 are movably installed, and projecting pins 22 for projecting a molded product and runner projecting pins 23 for projecting a solidified product in the primary injection material passage 18 are provided on the first and second projecting plates 20 and 21. And each protruding pin above
A return pin 24 for retracting 22,23 is attached respectively. A return spring 25 is attached to the return pin 24.

When molding an audio cassette half using the two-color molding die device configured as described above, first, at the same time as the start of mold clamping, the piston rod 13a of the hydraulic cylinder 13 is
Is moved forward to move the core back assembly 9 so that the tip surface of the movable mold body 10 is brought into close contact with the engraving surface 1a of the fixed mold plate 1 (first
See figure). In this state, the primary injection material injected from the first molding machine (not shown) guided by the locate ring 14 forms the primary injection material inside the sprue bush 16, the fixed mold plate 1, and the movable mold plate 4. The space for molding the frame of the cassette half is filled through the injection material passage 18. As a result, the frame body 26 is molded.

Next, when the piston rod 13a of the hydraulic cylinder 13 is retracted, the core back assembly 9 moves to move the movable mold body.
The tip surface of 10 becomes flush with the engraving surface 4a of the movable template 4, and a space for secondary injection material (for forming the window portion) is formed between this tip surface and the engraving surface 1a of the fixed template 1. To be done. In this state, the secondary injection material injected from the second molding machine (not shown) in which the locate ring 15 is guided is the secondary injection material passage formed inside the sprue bush 17 and the fixed mold plate 1. The space for the secondary injection material is filled via 19. As a result, the window portion 27 of the cassette half is molded, and the cassette half is molded in two colors.

In this way, when the cassette half is two-color molded, the core back assembly 9 is formed during the primary molding and the secondary molding.
Is reciprocated by the hydraulic cylinder 13, but at this time, since the steel ball 12 is mounted in the mounting groove 10a of the movable mold body 10 of the core back assembly 9, the movable mold body 10 is moved to the movable mold plate 4. On the other hand, it moves smoothly and no galling occurs between them. Therefore, the two-color molding can be continuously performed without any trouble, and the productivity can be improved. Also, the above steel balls
By interposing 12 between the movable mold body 10 and the movable mold plate 4, the clearance between the movable mold body 10 and the movable mold plate 4 can be made small, and burrs are generated in the molded product. Can be prevented as much as possible.

In the above embodiment, the rope ball is used as the friction reducing member.
Although the description has been given using 12, the ring or the roller having a circular cross section may be mounted in the mounting groove 10a of the movable mold body 10. Needless to say, instead of forming the mounting groove 10a in the movable mold body 10, the mounting groove may be formed in the movable mold plate 4 side.

[Effect of device]

As described above, in the present invention, a movable mold body that forms a space for filling the secondary injection material is provided in a part of the mold so as to be movable in the mold releasing direction of the molded product, and Between the movable mold body and a mold surrounding the movable mold body, a plurality of ropes fixed to one side of the movable mold body and the mold and slidably brought into point contact or line contact with the other side, Since the friction reducing member consisting of a steel roller or steel ring is provided, when the movable mold body moves in the mold releasing direction of the molded product, the movable mold body and the mold surrounding the movable mold body are provided. By reducing the frictional force between the movable mold body and the mold by the friction reducing member provided between the movable mold body and the mold around it, it is possible to prevent galling and The mold can be moved smoothly, and burr is prevented from occurring on the molded product. Has an excellent effect that kill.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention.
The figure is a cross-sectional view illustrating a mold during primary molding, and FIG. 2 is a cross-sectional view illustrating a mold during secondary molding. 1 ... Fixed mold plate, 4 ... Movable mold plate, 10 ... Movable mold body, 12
...... Rope ball (friction reducing member), 10a …… Mounting groove.

Claims (1)

[Scope of utility model registration request] 1. A two-color molding die device for molding a molded article by sequentially injecting a primary injection material and a secondary injection material into a space formed between a pair of opposing molds, the die comprising: A movable mold body that forms a space for filling the secondary injection material is provided in a part of the mold so as to be movable in the mold releasing direction of the molded product, and surrounds the movable mold body and the movable mold body. A plurality of steel balls fixed to one side of the movable mold and the mold and slidably in point contact with the other side between the mold and the movable mold and the other side fixed to the one side of the mold A friction reducing member consisting of a plurality of steel rollers slidably in line contact with the movable mold body or a steel ring fixed to one side of the mold and slidably in line contact with the other side. A mold device for two-color molding, which is provided.