JP2522693Y2 - Mold for cassette half molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a metal mold for forming a cassette half formed by a two-color molding method using a primary injection material portion and a secondary injection material portion. It is about type.

[Prior Art] Conventionally, for example, an audio cassette half formed by a two-color molding method as shown in FIGS. 4 and 5 is known. The cassette half includes a transparent secondary injection material portion 1 (hereinafter abbreviated as a “transparent portion”) formed at the center, and colored primary injection material portions 2 formed on both sides of the transparent portion 1. 3 (hereinafter abbreviated as “colored portion”).

As means for forming such a cassette half, first, in a state in which a portion corresponding to the transparent portion 1 of the cavity in the mold is closed with a movable mold, a primary injection material is inserted into the cavity corresponding to the colored portions 2.3. (Colored resin) to perform primary molding, and then move the movable mold to move the transparent portion 1
Is formed, and a secondary injection material (transparent resin) is supplied into the cavity to complete the secondary molding.

[Problem to be Solved by the Invention] However, in the above-described conventional cassette half, the transparent portion 1 of the cassette half is bent outward due to the pressure or the like at the time of injecting the secondary injection material, and the cassette half is bent outward. There was a tendency that the entire half was warped in the S1 and S2 directions in FIG.

Therefore, as a result of various studies by the present inventors, it has been found that the warpage of the cassette half can be prevented by changing the shape of the abutting surface between the transparent portion 1 and the colored portions 2 and 3. That is, when the colored portions 2 and 3 and the transparent portion 1 are overlapped one another in the thickness direction at the boundary portion, it is possible to prevent the cassette half from being warped.

The present invention has been made based on the above findings, and an object of the present invention is to provide a cassette half molding die capable of molding a high-quality cassette half without warpage.

Means for Solving the Problems Accordingly, the present invention provides a primary injection material portion and a secondary injection material by sequentially filling a cavity formed between opposed dies with a primary injection material and a secondary injection material. A mold half for molding a cassette half by means of a portion, a fixed mold plate forming one surface of the cassette half with a cavity surface, and the other of the cassette half being capable of approaching and separating from the fixed mold plate. A movable mold plate forming a surface, a core assembly slidably penetrated in the mold release direction with respect to the movable mold plate, and an assembly drive unit for moving the core assembly in the mold release direction. The core assembly has a tip surface set to be in close contact with the cavity surface at the time of primary injection material injection, and is separated from the cavity surface at the time of secondary injection material injection and includes only one layer of the secondary injection material portion. Formed A movable mold for a single-layer part for molding a portion to be molded, and a primary injection material portion which is further separated from the cavity surface at the time of secondary injection material injection while the tip surface is set to be separated from the cavity surface at the time of primary injection material injection. A movable part for a boundary part, which is formed by overlapping a boundary part with the secondary injection material part in the thickness direction, and the movable part for the one-layer part and the movable part for the boundary part are connected to each other to form a boundary with the cavity surface; A connecting pin is provided which allows the movable part to move forward and backward smaller than the movable part.

FIG. 1 is a view showing a cassette half according to an embodiment of the present invention.

The cassette half includes a transparent portion 10 and colored portions 20 and 30.

The colored portions 20 and 30 are formed with recesses 22 and 32 that open on the inner surface sides 21 and 31 and the transparent portion 10 side. As a result, the transparent portion 10 has extended portions 11 and 12 which extend from the inner surface 13 thereof and are filled in the recesses 22 and 32.
Is provided.

In the cassette half of the present embodiment, the recess 22
By filling the extension portions 11 and 12 into the inside of the
-The transparent part 10 and the transparent part 10 are overlapped in the thickness direction at the boundary parts P1 and P2.

Here, the width of the recesses 22 and 32 in the thickness direction, that is, the thickness of the extending portions 11 and 12 is set to half the thickness t of the cassette half, that is, 1/2 t. Here, the thickness of the extending portions 11 and 12 is preferably not less than 1 / 3t and not more than 1 / 2t.

Next, an example of a mold for molding the cassette half will be described with reference to FIGS.

The mold includes a fixed mold plate 40 forming the outer surface of the cassette half, a movable mold plate 41 capable of approaching and separating from the fixed mold plate 40 to form the inner surface of the cassette half, and a movable mold plate 42. The movable spacers 42 and 43 fixed to the lower surface of the movable spacers 42 and 43, and the movable mounting plate
And a core back assembly (core assembly) housed between the movable spacers 42 and 43 and slidably penetrated with respect to the movable receiving plate 41 in a releasing direction (vertical direction in FIG. 2). Body) 45.

A cavity 46 for forming a cassette half is formed between opposing surfaces of the fixed mold plate 40 and the movable mold plate 44. The thickness of the cavity 46 in the releasing direction is set to a thickness equal to the thickness t of the cassette half.

The fixed mold plate 40 has a flow path (not shown) for injecting the primary injection material and the secondary injection material into the cavity 46.
Are formed.

The core back assembly 45 has a transparent portion on the cassette half.
First movable mold for molding 10 (movable mold for boundary) 48
A second movable mold (movable mold for one layer) 47, a third movable mold (movable mold for boundary) 49, and a first receiving plate 50 to which lower ends of the second and third movable molds 48 are fixed. And the second receiving plate 51 to which the lower end of the first movable mold 47 is fixed, and the first and second receiving plates 50 and 51 can be separated by a half length t of half the thickness of the cavity 46. And a connecting pin 52 to be connected.

The length of the first movable mold 47 in the mold release direction is set to a length such that the leading end surface of the first movable mold 47 is in close contact with the lower surface of the fixed mold plate 40 during the primary injection material injection (FIG. 2). I have.

The length of the second and third movable dies 48 and 49 in the mold release direction is such that the tip of the second and third movable dies 48 and 49 is located at the bottom with respect to the lower surface of the fixed mold plate 40 when the primary injection material is injected. 46 thickness t
The length is set to be half the length of 1 / 2t apart.

Inside the movable mounting plate 44, a cylinder (assembly driving unit) 53 having a piston 54 is provided. One end of a piston rod 55 is attached to the upper surface of the piston 54. The other end of the piston rod 55 is connected to the second
It is attached to the lower surface of the receiving plate 51. The piston 54
Is configured to be able to move forward and backward, and at the time of forward movement, the tip of the first movable mold 47 is brought into close contact with the lower surface of the fixed mold 40,
At the time of retreat, the lower surface of the second receiving plate 51 can be brought into contact with the upper surface of the movable mounting plate 44.

The distance between the lower surface of the second receiving plate 51 and the upper surface of the movable mounting plate 44 is set to a distance equal to the thickness t of the cavity 46, and the lower surface of the second receiving plate 51 and the movable mounting plate 44 In a state where the upper surface is in contact with the first, second, and third movable molds 47,
The configuration is such that 48 and 49 and the upper surface of the movable mold plate 41 are located on the same plane.

Next, a method of forming a cassette half using the mold having the above configuration will be described.

First, in the mold clamping state, the piston 54 is advanced,
The distal end surface of the first movable die 47 is brought into contact with the lower surface of the fixed die 40.
At this time, the tip surfaces of the second and third movable dies 48 and 49 are half the thickness t of the cavity 46 with respect to the lower surface of the fixed mold plate 40.
The state is separated by 1 / 2t. This allows the movable mold plate
A cavity 46 for injecting the primary injection material can be formed between the solid mold plate 40 and the solid mold plate 41, and the cavity 46 for injecting the secondary injection material is formed in the first, second, and third movable molds. It can be closed by 47, 48, 49.

Next, a primary injection material is injected into the cavity 46 to form portions corresponding to the colored portions 20 and 30 of the cassette half. At this time, since the cavity 46 for injecting the secondary injection material is closed by the first, second, and third movable dies 47, 48, and 49, the recesses 22 and 32 are formed in the colored portions 20 and 30. can do.

Next, the piston 54 is retracted, and the second receiving plate 51 approaches the movable mounting plate 44. Since the second receiving plate 51 and the first receiving plate 50 are connected by the connecting pins 52 so as to be able to be separated by a length of 1/2 t, the first receiving plate 50 is first stopped while the first receiving plate 50 remains stopped. The two receiving plates 51 move by a length of 1 / 2t. The second and third
The tip surfaces of the movable dies 48 and 49 and the lower surface of the fixed die 40
When the second receiving plate 51 moves by a length of 1 / 2t, the end surfaces of the first, second, and third movable dies 47, 48, and 49 are flush with each other. Will be located. When the second receiving plate 51 is further moved downward, the first receiving plate 50 and the second receiving plate are moved.
51 moves together with a 1 / 2t interval.

Next, the lower surface of the second receiving plate 51 is brought into contact with the upper surface of the movable mounting plate 44, and at this time, the retraction of the piston 54 is stopped. According to the mold of the present embodiment, the separation distance between the lower surface of the second receiving plate 52 and the upper surface of the movable mounting plate 44 is previously set to the length t.・ 3rd movable type 47 ・ 48
The tip surface of 49 and the upper surface of the movable mold plate 41 are located on the same plane. In this way, a cavity 46 for injecting the secondary injection material can be formed between the solid mold plate 40 and the movable mold plate 41.

Next, a secondary injection material is injected into the cavity 46 formed as described above. This secondary injection material has a colored portion 20
Since the recesses 22 and 32 formed in 30 are filled, the extending portions 11 and 12 can be formed in the transparent portion 10. In this way, it is possible to obtain a cassette half in which the colored portions 20 and 30 and the transparent portion 10 overlap each other in the thickness direction at the boundary.

If the thickness of the extension parts 11 and 12 is changed,
The distance between the distal end surfaces of the third movable dies 48 and 49 and the lower surface of the fixed die 40 and the distance between the first receiving plate 50 and the second receiving plate 51 that can be separated by the connecting pin 52 are determined by the extension 11. The length may be set equal to the thickness of twelve.

In the cassette half of the present embodiment, the colored portion
The recesses 22 and 32 that open on the inner surface sides 21 and 31 of 20 and 30 are formed, and the extending portions 11 and 12 provided in the transparent portion 10 are recessed 22 and 32.
By filling the inside, the colored portions 20 and 30 and the transparent portion 10 are configured to overlap each other in the thickness direction at the boundary portions P1 and P2, but the configuration is not limited thereto, and the recesses 22 and 30 are not limited to this.
32 is configured to be open on the outer surface side of the colored portions 20 and 30 and the transparent portion 10 side, and the extending portions 11 and 12 are continuously extended from the outer surface of the transparent portion 10 to extend the extending portion 11・ 12 is recess 22 ・
A configuration in which 32 are filled may be used. In short, if the colored portions 20 and 30 and the transparent portion 10 are configured to overlap each other in the thickness direction at the boundary portions P1 and P2, the extending portion 11
The 12 and the recesses 22 and 32 may be provided on the inner surface side or on the outer surface side.

[Effects of the Invention] The present invention connects the movable layer for the one-layer part and the movable mold for the boundary part, and allows the movable part for the boundary part to move back and forth with respect to the cavity surface smaller than the movable part for the one-layer part. The structure formed with the connecting pins that make the boundary portion movable mold allows the portion formed by the boundary movable mold to be thinner than the portion formed by the partial movable mold, and the primary injection material portion and the secondary injection material to be formed. The boundary with the part can be formed by overlapping each other in the thickness direction. Therefore, a high-quality cassette half without warpage can be easily formed.

[Brief description of the drawings]

FIG. 1 is a view showing a cassette half according to an embodiment of the present invention. FIG. 2 is a sectional view of the cassette half. FIG. 2 and FIG. FIG. 2 is a cross-sectional view showing a mold in which a primary injection material is injected, and FIG. 3 is a cross-sectional view showing a die in a state where a secondary injection material is injected. 4 and 5 are views showing a conventional cassette half, FIG. 4 is a perspective view of the cassette half, and FIG. 5 is an enlarged sectional view taken along line VV in FIG. 10 ... Transparent part (secondary injection material part), 20/30 ... Colored part (primary injection material part), P1, P2 ... Boundary part.

Claims (1)

(57) [Scope of request for utility model registration] 1. A cassette for forming a cassette half by a primary injection material portion and a secondary injection material portion by sequentially filling a cavity formed between opposed molds with a primary injection material and a secondary injection material. In the half-molding mold, a fixed mold plate forming one surface of the cassette half with a cavity surface, a movable mold plate which can be approached and separated from the fixed mold plate and forms the other surface of the cassette half, A core assembly slidably penetrated in the mold release direction with respect to the movable mold plate; and an assembly drive unit for moving the core assembly in the mold release direction, wherein the core assembly is A one-layer portion in which a tip surface is set to be in close contact with the cavity surface at the time of primary injection material injection and which is separated from the cavity surface at the time of secondary injection material injection to form a portion formed by only one secondary injection material portion; for A dynamic mold, wherein a front end surface is set to be separated from the cavity surface at the time of primary injection material injection, and further separated from the cavity surface at the time of secondary injection material injection, and a boundary between the primary injection material portion and the secondary injection material portion. The movable part for the boundary portion, which is formed by overlapping the parts in the thickness direction, and the movable die for the one-layer part and the movable part for the boundary part are connected to each other, and the amount of advance / retreat of the movable part for the boundary part with respect to the cavity surface is reduced. A connecting pin which is smaller than the movable mold for the one-layer part and is capable of moving forward and backward.