JP3398946B2 - Mold device for shutter molding of recording disk - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold device for molding a shutter of a recording disk for molding a resin shutter such as a micro floppy disk.

[0002]

2. Description of the Related Art As shown in FIG. 5, a micro-floppy disk has a magnetic disk 3 built in a shell case 2 having an opening window 1 and a shutter 4 slidably mounted on the shell case 2 to provide a magnetic disk. The opening window 1 for exposing a part of 3 is opened and closed. The shutter 4 is formed in a substantially U-shaped cross section by a pair of main plate portions 5 that face each other with a small gap therebetween and a connecting portion 6 that integrally connects the edge portions of the main plate portions 5 to each other. Opening windows 7 that overlap the opening windows 1 of the shell case 2 are formed in the main plate portions 5 respectively. The shutter 1 may be made by pressing a metal plate,
Some are made of resin integrally molded. FIG. 6 shows a cross-sectional view of an example of the resin shutter 4. As shown in FIG. 6, the shutter 4 is attached to the shell case 2 on the inner surfaces of the main plate portion 5 and the connecting portion 6 of the shutter 4. Projections 8 and 9 are formed. An opening hole 10 for die cutting, which is necessary to form the protrusions 8 and 9, is formed in the edge portion of the main plate portion 5 on the connecting portion 6 side.

The shutter 4 is generally molded by using a mold device as shown in FIGS. 7 and 8. In the figure, 11 is a fixed type and 12 is a movable type. The fixed die 11 and the movable die 12 move in the vertical direction shown in FIG. 8 (hereinafter referred to as the main die opening / closing direction) to open and close,
A cavity 13 in the shape of the shutter 4 is formed between the two when the mold is closed. The main mold opening / closing direction is set to be a direction orthogonal to the connecting portion 6 of the shutter 4 and along the main plate portion 5. The fixed mold 11 has a cavity block 14 forming the outer surface of the connecting portion 6. The cavity block 14 is provided with a gate 15 which is a resin injection port into the cavity 13.

The movable die 12 has a core holder 16 and a center core 17 fixed to the core holder 16. The center core 17 has a thin flat plate portion 18 forming the inner surface of the shutter 4. ing. A pair of slide cores 19 are attached to the core holder 16 so as to be slidable in a direction orthogonal to the main plate portion 5 of the shutter 4. The two slide cores 19 form the outer surfaces of the two main plate portions 5, respectively. A convex portion 20 for forming the opening window 7 of the main plate portion 5 is formed on one or both of the facing surfaces of the slide core 19 and the center core 17. At the same time, the slide core 19 is provided with a convex portion 21 for forming the opening hole 10 of the main plate portion 5 and the protrusions 8 and 9. Further, each slide core 19 is formed with a core holder facing surface 22 facing the center core 17 side. On the other hand, the core holder 16 is formed with a pair of slide core facing surfaces 23 against which the core holder facing surfaces 22 of the slide cores 19 abut when the mold is closed. Further, the core holder 16 is provided with a pair of side cores 24 along both side surfaces of the center core 17 and the slide core 19, that is, the surfaces parallel to the sliding direction of the slide core 19 and the main mold opening / closing direction. .

A spring 25 is provided between the facing surfaces 22 and 23 of the core holder 16 and the slide core 19 for opening the slide core 19 with respect to the center core 17 as the mold is opened. On the other hand, the fixed mold 11 is provided with a locking block 26 for pressing the slide core 19 and closing the center core 17 when the mold is closed. In this locking block 26, an inclined surface 27 inclined in a predetermined direction with respect to the main mold opening / closing direction abuts an inclined surface 28 formed on the slide core 19.

During molding, the molten thermoplastic resin flows from the gate 15 to the cavity 13 with the mold closed as shown.
Filled inside. Then, after the resin filled in the cavity 13, that is, the shutter 4 is cooled and solidified,
The mold is opened. When the fixed mold 11 and the movable mold 12 are opened at the time of opening the mold, the molded shutter 4 is first fixed.
Leave 11 Further, in conjunction with the opening of the fixed die 11 and the movable die 12, the force of the spring 25 causes the slide core 19 to move in a direction away from the center core 17 with respect to the core holder 16, so that the main plate portion 5 of the shutter 4 can be moved. Leave. further,
The shutter 4 is ejected toward the fixed mold 11 side by a protrusion pin (not shown) provided on the movable mold 12 side, separated from the center core 17, and taken out.

After that, the mold is closed again and the molding is repeated. When the mold is closed, the locking block 26 has an inclined surface 2
By pushing the slide core 19 at 7 and 28, the slide core moves in the direction of approaching the center core 17 with respect to the core holder 16, as opposed to when the mold is opened. When the cavity block 14 hits the side core 24 and the slide core 19 and the mold closing is completed, the locking block 28 presses the slide core 19 to cause the core holder 16
The core holder facing surface 22 of the slide core 19 abuts on the slide core facing surface 23, and these slide cores 19 are positioned.

[0008]

By the way, the cavity
When the inside of the cavity 13 is filled with resin, a high pressure is applied to the inside of the cavity 13, and the flat plate portion 18 of the center core 17 is
A load of 500 to 600 kg is applied. However, since the flat plate-shaped portion 18 is thin and is fixed to the core holder 16 only on the lower side thereof, inclination and bending are likely to occur due to the resin pressure. For example, if the flat plate portion 18 is tilted, the thicknesses of both main plate portions 5 of the shutter 4 are varied, resulting in defective molding. In particular, the thickness of the main plate 5 is 0.4 mm, which is very thin by regulation, and a slight variation in thickness causes defective molding. Even in the conventional shutter molding die device,
The projections 20 and 21 of the slide core 24 forming the opening window 7 and the opening hole 10 abut against the flat plate portion 18, but with only that,
Deformation of the flat plate portion 18 cannot be sufficiently prevented, and if the slide core 24 abuts against the flat plate portion 18, the flat plate portion 18 may be undesirably deformed. If, for example, even a part of the main plate portion 5 has a portion thicker than the regulation, it is a defective product.

The present invention is intended to solve such problems, and it is possible to surely prevent the center core from tilting or flexing, and to mold a shutter having a main plate portion of a prescribed thickness to mold a shutter for a recording disk. An object is to provide a mold device for use.

[0010]

According to a first aspect of the present invention, there is provided a mold device for molding a shutter for a recording disk, comprising: a pair of main plate portions facing each other with a small gap therebetween in order to achieve the above object. In a mold device for molding a shutter including a connecting portion that integrally connects the edge portions of the main plate portion to each other,
A core holder, a center core integrally formed with the core holder to form an inner surface of the shutter, and a core holder slidably attached to the core holder in a direction intersecting with a main plate portion of the shutter to form outer surfaces of both main plate portions. A pair of slide cores, side cores provided on the core holder and located on both sides of the center core and both slide cores, respectively, and opened and closed in a direction intersecting with a connecting portion of the shutter with respect to the center core and the slide cores. And a cavity block forming an outer surface of the center core, and the side core is provided with a recess into which the side edge portion of the center core fits.

At the time of molding, in a mold closed state, a molding material is filled in a cavity formed between the center core, the slide core and the cavity block. At this time, the side edges of the center core that forms the inner surface of the shutter are fitted into the recesses of the side core, so that the center core is prevented from tilting or bending due to the pressure of the molding material, and thus the specified thickness A shutter having a main plate portion of is molded. When the mold is opened, the center core, the slide core, the side core, and the cavity block are opened.
The slide core opens to the center core and separates from the main plate of the shutter.

According to a second aspect of the present invention, in the mold device for molding a shutter for a recording disk according to the first aspect of the present invention, the slide core is provided with an abutting portion facing the center core side, and the side core is provided with a die. A receiving portion is provided to which the abutting portion of the slide core abuts when closed.

The slide cores are positioned with respect to the side cores by abutting the abutting portions of the slide cores against the receiving portions of the side cores in the mold closed state. Further, since the center core is positioned with respect to the side core by fitting the side edge portion thereof into the recess of the side core, the slide core is positioned with respect to the center core.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a mold device for molding a shutter for a recording disk according to the present invention will be described below with reference to the drawings. First, a first embodiment will be described with reference to FIG. In the present embodiment, the molded shutter 4 is the same as that shown in FIGS. 5 and 6 described above, and therefore, corresponding parts will be denoted by the same reference numerals and description thereof will be omitted. Further, since the mold apparatus of the present embodiment has a similar configuration to the mold apparatus shown in FIGS. 7 and 8 described above, the corresponding parts are designated by the same reference numerals and their description is omitted. Omit it. In the mold device of the first embodiment, the center core 17 and the slide core 19 provided on the core holder 16 are provided.
Groove-shaped recesses in which both side edge portions 31 of the flat plate-shaped portion 18 of the center core 17 are fitted to both side cores 24 located on both sides of
32 are provided.

Further, on both sides of both slide cores 19 slidably assembled to the core holder 16, step-shaped butting parts which are orthogonal to the sliding direction of these slide cores 19 and face the center core 17 side. 33 are formed. On the other hand, the surface of the side core 24 orthogonal to the sliding direction of the core holder 16 forms a receiving portion 34 against which the abutting portions 33 of the slide core 19 abut when the mold is closed. That is, when the cavity block 14 (see FIG. 8) on the fixed mold 2 side presses the slide core 19 in the mold closed state, the slide core 19
The abutting portions 33 of the abutting portions abut on the receiving portions 34 of the side cores 24, respectively. On the other hand, in this state, the dimensions are set so that a minute gap c of, for example, about 0.01 mm is formed between the slide core 19 and the center core 17.
This clearance c is provided so that the slide core 19 does not abut against the center core 17 and interfere with the positioning of the side core 24 and the center core 17, but the flat plate-shaped portion 18 bends within the range of the clearance c. However, it is set to a value that is acceptable as the product dimensional error. If the slide core 19 is directly abutted against the center core 17, a biased force is applied to the center core 17, which may cause the center core 17 to tilt or bend. In addition, in this embodiment, the slide core facing surface 23 of the core holder 16 is
The dimensions of the slide core 19 and the core holder facing surface 22 of the slide core 19 are set so as not to abut each other.

At the time of molding, in the mold closed state, the cavity 13 formed between the center core 17, the slide core 19 and the cavity block 14 is filled with resin as a molding material. At this time, since both side edge portions 31 of the flat plate-shaped portion 18 of the center core 17 forming the inner surface of the shutter 4 are fitted into the recessed portions 32 of the both side cores 24, the thin flat plate-shaped portion 18 due to the pressure of the resin is formed. The inclination and bending of the are prevented. As a result, the shutter 4 having the main plate portion 5 having the specified thickness is formed. That is, it is possible to prevent variations in the thickness of both main plate portions 5 and also to make the thickness of each main plate portion 5 uniform. Also, with the mold closed, the receiving part of the side core 24
The slide core 19 is positioned with respect to the side core 24 by the abutting portion 33 of the slide core 19 hitting the slide core 34. In addition, as described above, the center core 17
Since the side edge portion 31 is fitted into the recess 32 of the side core 24 and thus positioned with respect to the side core 24, the slide core 24 is positioned with respect to the center core 17. In this way, the positioning of the center core 17 and the slide core 24 can be made more reliable, so that the accuracy of the thickness of the main plate portion 5 can be further improved.

As in the first embodiment, if the both side edges 31 of the center core 17 are fitted in the recesses 32 of the side core 24, respectively, the positioning effect is higher.
Even if only one side edge 31 of 17 is fitted into the recess 32 formed in the side core 24, some effects can be obtained.

In the first embodiment, the center core
Although the side edge portion 31 and the recessed portion 32 of 17 are made straight,
It may be tapered as in the second embodiment shown in FIG.

Next, a reference example will be described with reference to FIGS. Since the mold device of the reference example has a similar configuration to the mold device shown in FIGS. 7 and 8 described above, the corresponding parts are designated by the same reference numerals and the description thereof will be omitted. To do. In the mold device of the reference example , the convex portions 41 are formed on both end portions of the surface of the flat portion 18 of the center core 17 on the cavity block 14 side. These convex portions 41 are located outside the portion of the flat plate portion 18 that forms the shutter 4. On the other hand, the cavity block 14 is formed with a pair of concave portions 42 into which the convex portions 41 of the center core 17 are fitted when the mold is closed. These convex portion 41 and concave portion 42,
It is preferable to form a taper so that the mold can be fitted smoothly when the mold is closed.

A stepped abutting portion 43, which is orthogonal to the sliding direction of the slide cores 19 and faces the center core 17 side, is formed by a convex portion at a position on the cavity block 14 side of both slide cores 19. ing. On the other hand, the cavity block 14 is formed with a pair of receiving portions 44, which the abutting portions 43 of the slide core 19 abut when the mold is closed, as stepped surfaces. That is, when the cavity block 14 on the fixed mold 2 side presses the slide core 19 in the mold closed state, the abutting portions 43 of the slide core 19 abut the receiving portions 44 of the cavity block 14, respectively. On the other hand, in this state, the slide core 19 and the center core
The dimensions are set so that a minute gap c of, for example, about 0.01 mm is formed between the groove 17 and the groove 17. This clearance c is provided so that the slide core 19 does not abut against the center core 17 and interfere with the positioning of the cavity block 14 and the center core 17, but within the range of the clearance c Even if it bends, it is set to a value that is acceptable as a dimensional error of the product. Further, in the present reference example , the dimension is set so that the slide core surface 23 of the core holder 16 and the core holder surface 22 of the slide core 19 do not abut each other.

In this reference example , as shown in FIG.
Although the convex portion 20 forming the opening window 7 of the shutter 4 is formed on the center core 17, it may be formed on the slide core 19 side.

At the time of molding, with the mold closed, the cavity
Fill 13 with resin. At this time, since the convex portions 41 at both ends of the surface of the flat portion 18 of the center core 17 on the side of the cavity block 14 are fitted into the pair of concave portions 42 of the cavity block 14, respectively, the thin wall due to the pressure of the resin is formed. The flat plate-shaped portion 18 is prevented from tilting or bending. This allows
The shutter 4 having the main plate portion 5 having a specified thickness is molded. That is, it is possible to prevent variations in the thickness of both main plate portions 5 and also to make the thickness of each main plate portion 5 uniform.

Further, when the abutting portion 43 of the slide core 19 abuts the receiving portion 44 of the cavity block 14 in the mold closed state, the slide core 19 is positioned with respect to the cavity block 14. Further, as described above, since the center core 17 is positioned with respect to the cavity block 14 by fitting the convex portion 41 into the concave portion 42 of the cavity block 14, the center core 17 slides with respect to the center core 17. The core 24 will be positioned. In this way, the positioning of the center core 17 and the slide core 24 can be made more reliable, so that the main plate 5
The thickness accuracy of can be further improved.

As in the above reference example , the center core
Providing convex portions 41 on both ends of the surface of the cavity block 14 side in 17 and fitting both convex portions 41 into the concave portions 42 of the cavity block 14 provides a higher positioning effect, but the cavity in the center core 17 Even if only one end of the surface on the block 14 side is provided with the convex portion 41 that is fitted into the concave portion 42 of the cavity block 14, some effects can be obtained.

Furthermore, the present invention is not limited to the above-mentioned embodiment, but various modifications can be made. For example, the configuration of the first or second embodiment and the configuration of the reference example may be combined and implemented. Further, in the above-described embodiment, the shutter for MFD was described as an example, but the present invention can be applied to general shutters having the same shape and structure.

[0026]

According to the first aspect of the present invention, in a mold device for molding a shutter in which a pair of main plate portions opposed to each other with a small gap therebetween are connected by a connecting portion, a shutter device is provided. Since the side core provided on the core holder together with the center core forming the inner surface is provided with the recess into which the side edge portion of the center core fits, when filling the molding material,
It is possible to reliably prevent the center core from tilting or bending due to the pressure of the molding material, and it is possible to mold a shutter having a main plate portion with a prescribed thickness.

According to the invention of claim 2, in addition to the effect of the invention of claim 1, the slide core is provided with an abutting portion facing the center core side, and the side core abuts the slide core when the mold is closed. Since the receiving portion with which the portion abuts is provided, the positioning of the center core and the slide core can be made more reliable, and the accuracy of the thickness of the main plate portion can be further improved.

[Brief description of drawings]

FIG. 1 is a plan view of a movable mold showing a first embodiment of a mold device for molding a shutter for a recording disk of the present invention.

FIG. 2 is a plan view of a movable mold showing a second embodiment of the mold device for molding the shutter of the recording disk of the present invention.

3 is a view to a cross-sectional view of the shutter mold <br/> equipment of the recording disk of the embodiment.

FIG. 4 is a perspective view of the above center core.

FIG. 5 is a perspective view of a micro floppy disk.

FIG. 6 is a sectional view of the same shutter.

FIG. 7 is a plan view of a movable mold showing an example of a conventional mold device for molding a shutter of a recording disk.

FIG. 8 is a sectional view of the same.

[Explanation of symbols]

4 shutter 5 Main plate 6 connection 14 cavity block 16 core holder 17 Center core 19 slide core 24 side core 31 Center core side edge 32 Side core recess 33 Slide core butting part 34 Side core receiving part

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B29C 33/02-33/54 B29C 45/26 G11B 23/03

Claims (2)

(57) [Claims] 1. A mold apparatus for molding a shutter, comprising: a pair of main plate portions facing each other with a small gap therebetween, and a connecting portion integrally connecting end edges of the main plate portions to each other. A holder, a center core integrally formed with the core holder to form the inner surface of the shutter, and a pair that is slidably assembled to the core holder in a direction intersecting with the main plate portion of the shutter and forms outer surfaces of both main plate portions, respectively. Slide cores, side cores provided on the core holder and located on both sides of the center core and both slide cores, respectively, and the center core and the slide cores are opened and closed in a direction intersecting with the connection portion of the shutter. A cavity block forming an outer surface, and the side core is provided with a recess into which the side edge of the center core is fitted. A mold device for molding a shutter of a recording disk, which is characterized in that: 2. The slide core is provided with an abutting portion facing the center core side, and the side core is provided with a receiving portion with which the abutting portion of the slide core abuts when the mold is closed. Item 1. A mold device for molding a shutter of a recording disk according to item 1.