JPH03216311A - Mold assembly for molding disc case - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a molding device for molding a disk case for housing a disk-shaped storage disk body such as a magnetic disk, an optical disk, an optical disk, etc. Regarding.

[Conventional technology]

Conventionally, when molding this type of disc case, gates (injection ports) were provided at positions corresponding to the four corners of the surface of the disc case, and molten resin was supplied into the cavity from these four gates to mold the disc. The case is molded, so the molten resin injected from the four gates flows toward the center of the disc case.

[Problem to be solved by the invention]

By the way, when forming with the four-point gate as described above, especially in the upper case where there is no through hole in the center part,
Gas venting in the central portion tends to be insufficient, resulting in problems such as a wet surface appearing on the surface of the molded product, or pressure not being applied uniformly within the molded product, resulting in warping of the molded product.

Therefore, in order to solve the above problem, an injection molding gate trace is provided only near one end of the face plate part, and the side end opposite to the gate trace is the resin filling end position, and the gate A disk cartridge has been proposed in which a resistance part is provided on the side end opposite to the mark to provide resistance to the flow of resin during case molding (Japanese Patent Application Laid-Open No. 1993-1910).
(See Publication No. 217780).

However, in the above-mentioned conventional disk cartridge, since the resistance part is provided at the side end opposite to the gate mark, the flow of resin during molding is obstructed, which has a negative effect on the molding of the disk cartridge. There is a problem.

The present invention has been made in view of the above circumstances, and its purpose is to allow resin to flow smoothly inside the cavity and to allow smooth degassing, as well as to prevent the molded product from becoming wet or warped. It is an object of the present invention to provide a mold device for molding a disk case that can prevent the occurrence of such defects.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a mold apparatus for molding a disk case for storing a disk-shaped storage disk body by supplying molten resin to a cavity in the mold, which includes the molten resin. Two injection ports for the cavity are placed on the engraved surface of the mold in a part that is normally covered and hidden by a shutter and that corresponds to the outside of the storage section of the storage disk body, and A gas venting portion is formed in the center, and the thickness of the portion of the cavity corresponding to the outside of the storage portion of the storage disk body is set to be larger than the thickness of the portion of the cavity that corresponds to the storage portion of the storage disk body. This is what I did.

[Effect]

In the mold device for molding a disk case of the present invention,
The molten resin is supplied into the cavity from two injection ports (gates) placed on the engraved surface of the mold, which is a part that is normally covered and hidden by the shutter and corresponds to the outside of the storing section of the storage disk body. The thickness of the storage disc body is set to be larger than the thickness of the part corresponding to the storage part of the storage disc body, and the liquid flows more smoothly through the part corresponding to the outside of the storage part of the storage disc body, and reaches the central part of the cavity on the side far from the injection port. When the resin reaches the formed gas venting part, filling of the entire space in the cavity with the resin is completed.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 5.

FIG. 1 is a sectional view showing a part of a mold apparatus for molding an upper case 1 for a floppy disk as shown in FIGS. 2 and 3. FIG. The upper case 1 is formed into a substantially square thin-walled surface, and a shutter 6 is provided on the surface 1a.
A shutter area portion 1b for attaching a label and a label area portion 1c for pasting a label are each formed in a slightly recessed state than the other portions. Further, the upper case 1 is formed with a window 1d for introducing a magnetic head and a hole 1e for a write protector. Further, on the inner surface 1f side of the upper case 1, an outer frame portion 1g is formed over almost the entire outer edge thereof, and an arcuate rib portion 1h is formed continuous with the outer frame portion 1g. The inner side of the rib portion 1h is used as a disk storage portion 11 for storing a disc-shaped storage disk, and the outer side of the lip portion 1h is the upper right side in FIG. , a spring storage portion 1j that stores a spring for biasing the shutter 6 to the right. Furthermore, the thickness of the outer face plate portion of the disk body storage portion 11 is set larger than the thickness of the disk body storage portion 11. In particular, the thickness of the face plate portions at the lower left corner and the lower right corner in FIG.

The mold for molding the upper case 1 configured as described above is
As shown in FIG. 1, a fixed mold plate 2 has an engraved surface for forming the surface 1a of the upper case 1, and a movable mold plate 3 has an engraved surface for forming the inner surface 1f of the upper case 1. An injection port (gate) 5 for injecting the molten resin into the cavity 4 formed between the templates 2 and 3 is a second gate.
As shown in the figure, the 7th soter area portion 1b of the upper case 1
This is the part that is covered and hidden by the shutter 6 which is biased by the spring inside (shown as the gate mark 1k in Fig. 2), and as shown in Fig. 3, the disc body of the upper case 1. It corresponds to the outside of the storage part 11, located as close to the center 7 of the case 1 as possible, and at a symmetrical position with respect to the center line ρ (in Fig. 3, it appears as a protrusion 1a facing the gate trace 1k). It is formed on the engraving surface of the fixed template 2. Further, a plurality of gas vent inserts 8 are attached to the movable mold plate 3, and the gas vent inserts 8 are placed opposite the window portion 1d across the center 7, as shown in FIG. placed at the corresponding position on the side. In addition,
In FIG. 1, the upper case 1 inside the cavity 4 has a second
The figure shows a cross section taken along line I-1, and FIG. 3 shows a cross section taken along line I'-1'.

When molding the upper case 1 for a floppy disk using the mold device configured as described above, as in the past, the space between the fixed mold plate 2 and the movable mold plate 3 is closed, and both molds are molded. Board 2,
3. Molten resin is supplied from a pair of injection ports 5 into the cavity 4 to be formed.

At this time, the injection port 5 is placed at a symmetrical position with respect to the center line ρ.
They are arranged in a portion covered and hidden by the shutter 6 in the shutter area portion 1b of the upper case 1, and are formed at a position corresponding to the center 7 of the upper case 1 as much as possible outside the disk body storage portion 11. , the thickness of the portion of the cavity 4 corresponding to the outer face plate portion of the disk body storage portion 11 is set larger than the thickness of the portion of the cavity 4 corresponding to the disk body storage portion 11, and the central portion on the side far from the injection port 5; Since the gas venting insert 8 is attached to the movable mold plate 3, the resin injected into the cavity 4 from the injection port 5 is
It flows from one end side to the other end side (the degassing insert 8 side), and is filled from the thick part (outside of the disc body storage part 11) to the thin part (the disc body storage part 1i), and finally degassed. Reach nest 8.

As a result, the molten resin is sufficiently supplied to the thin-walled parts, and the flow of the molten resin is smoothly arranged, so that the resin is reliably distributed to each part, and degassing is easily performed.

Therefore, a product of good quality can be obtained without causing defects such as a wet surface or warping in the molded product.

In the above embodiment, the molding of the upper case 1 was explained, but as shown in FIGS. 4 and 5, the lower case 9 was molded.
The same applies to molding.

〔Effect of the invention〕

As explained above, the present invention provides a mold apparatus for molding a disk case for storing a disc-shaped storage disk body by supplying a molten resin to a cavity in the mold. Two injection ports are placed on the engraved surface of the mold in a part that is normally covered and hidden by a mirror and that corresponds to the outside of the storage section of the storage disk body, and the injection port is located on the side of the cavity far from the injection port. A scrap removal portion is formed in the center, and a thickness of a portion of the cavity corresponding to the outside of the storage portion of the storage disk body is set to be larger than a thickness of a portion of the cavity that corresponds to the storage portion of the storage disk body. Therefore, it was supplied into the cavity through injection ports (gates) placed at two points on the engraved surface of the mold, which is a part that is normally covered by a shutter and corresponds to the outside of the storage section of the storage disk body. The thickness of the molten resin is thicker than that of the part corresponding to the storage part of the storage disc body.It flows more smoothly through the part corresponding to the outside of the storage disc part of the set storage disc body, and from the above injection port of the cavity. By reaching the gas vent formed in the center of the far side and completing filling the entire space within the cavity,
Each part in the cavity can be reliably filled with resin, gas can be vented smoothly, and problems such as wetting surfaces and warping can be prevented from occurring in the molded product.

[Brief explanation of drawings]

Figure 1 is a sectional view showing one embodiment of the present invention, Figures 2 and 3 are
The figures show an example of an upper case molded using the molding device of the present invention. Fig. 2 is a plan view of the upper case as seen from the surface side, Fig. 3 is a bottom view of the upper case as seen from the inner side, Figures 4 and 5 show an example of the lower case molded using the molding device of the present invention. Figure 4 is a plan view of the lower case as seen from the surface side, and Figure 5 is the inner surface of the lower case. This is a bottom/top view seen from the side. 1... Upper case for Flo/P disk, 2... Fixed template, 3... Movable template, 4... Cavity, 5...
- Inlet (gate), 8... Gas venting insert (gas venting part), 9... Lower case, 11... Disc body storage part.

Claims (1)

[Scope of Claims] A molding die device for supplying molten resin to a cavity in the mold to mold a disk case for housing a disk-shaped storage disk body, comprising: an injection port for the molten resin into the cavity; are placed at two points on the engraved surface of the mold, which is a part that is normally covered and hidden by a shutter, and corresponds to the outside of the storing section of the storage disk body, and a gas venting section is placed in the center of the cavity on the side far from the injection port. and a thickness of a portion of the cavity corresponding to the outside of the storage portion of the storage disk body is set to be larger than a thickness of a portion of the cavity corresponding to the storage portion of the storage disk body. Mold device for molding disc cases.