JP2961723B2 - Mold equipment - 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 apparatus for molding a tray or the like which is a component of a compact disc storage case and which holds a compact disc in a detachable manner.

[0002]

2. Description of the Related Art An example of a compact disk storage case will be described with reference to FIG. In the figure, 1 is a compact disc, 2 is a circular opening formed in the center of the compact disc 1, 3 is a non-recording portion around the opening 2, and 4 is a periphery of the non-recording portion 3 Recording section. The illustrated compact disc 1 is a single-storage type that accommodates one compact disc 1 as described above. A transparent base 11, a tray 12 attached to the base 11, and a tray 12 Cover 13 that can be opened and closed freely
It consists of The cover 13 is pivotally attached to the base 11 by a hinge 14. In the following description, the hinge portion 14 side is referred to as a rear side. The base 11
Is a molded article made of a transparent resin and has a shallow rectangular box shape. On the left and right sides of the base 11, a notch 16 for finger hooking, a pair of notches 17 for storing and holding a label press, and a plurality of tray mounting holes 18 are formed. The cover 13 is also a molded product made of a transparent resin, and has a rectangular shape. A pair of label holders 19 for holding a label are formed on the inner surfaces of the left and right sides, respectively. The hinge portion 14 is provided on an arm portion 20 protruding rearward from both right and left sides of the cover 13. Further, as shown in FIG. 5, the tray 12 is a molded product made of an opaque resin, and has a rectangular shape. And tray
An exposed portion 21 for closing the position between the arms 20 when the cover 13 is closed is formed at the rear portion of the cover 12 so as to protrude to the front side (the side shown in FIG. 4). The tray 12 is formed with a circular disk storage portion 22 that is recessed toward the rear side (the side shown in FIG. 5). Further, on both left and right sides of the tray 12, notch portions 23 for finger hooking are formed facing the disk storage portion 22, respectively, and a pair of label holding portions 24 are formed so as to be recessed to the back side. A pair of mounting projections 25 are formed on the outer surface. The notches 23 for hooking both fingers are respectively continuous with the notches 16 for hooking both fingers of the base 11, and are used for putting fingers on the compact disc 1 when the compact disc 1 is attached or detached. The label holding section 24 is provided with a label holding notch 17 of the base 11.
When the cover 13 is closed, the label holder 19 of the cover 13 is stored. Further, the mounting projection 25 is engaged with the tray mounting hole 18 of the base 11,
The tray 12 is stopped on the base 11. A circular pedestal portion 26 is formed at the center of the disk storage portion 22 so as to protrude toward the front side. The pedestal 26 holds the non-recording section 3 of the compact disc 1 and keeps the recording section 4 of the compact disc 1 in a non-contact state with the bottom surface in the disc storage section 22. Further, at the center of the pedestal portion 26, a disk holding portion 31 which elastically expands and contracts and is engaged with the opening hole 2 of the compact disk 1 so as to be detachably engageable and holds the compact disk 1 bulges to the front side. It is formed. This disk holding portion 31 as a bulging portion is composed of a plurality of hook-shaped protrusions 32 arranged along the circumference, and the space between these hook-shaped protrusions 32 forms a through groove 33, so that the disk holding portion 31 elastically expands and contracts. It is possible. And, the through groove 33,
It extends radially from the circular opening 34 between the tips of the hook-shaped projections 32 to the pedestal 26. Further, the outer peripheral surface of the disk holding portion 31 is in a natural state, and has an inverse tapered surface 35 whose diameter gradually increases toward its tip. this is,
This is to ensure that the compact disc 1 is held.

In the injection molding of such a tray 12, a mold apparatus having a fixed mold and a movable mold which moves in directions indicated by A and B in FIG. 5 when the mold is opened is used. In the conventional mold apparatus, the front side including the outer surface of the disk holding portion 31 of the tray 12 is formed by a fixed die, and the back side including the inner surface of the disk holding portion 31 of the tray 12 is formed by a movable die. In order to make the gate mark invisible and to increase the commercial value, the gate is provided as a side gate as shown by a chain line arrow a in FIG.
For example, the tray 12 is opened to the reinforcing rib 36 on the front surface of the tray 12 instead of the front side. In contrast, tray 12
The rear side of the tray is formed by a fixed mold, the front side of the tray is formed by a movable mold, and the gate is used as a valve gate. FIG. 5 shows a solid arrow b.
As shown by, the valve gate is opened to a reinforcing rib 37 on the back side of the exposed portion 21 or the like. However, when the back side of the tray 12 is formed by a fixed mold as described above, because of the shape, the release resistance of the tray 12 from the fixed mold side becomes large, so that in addition to the movable mold side, the tray 12 is formed on the fixed mold side. Also has a protruding pin. That is, as shown by the hatched pin marks 38 in FIG. 5, a large number of projected pins are provided on the entire back surface of the tray 12 on the fixed mold side. On the other hand, as shown by the hatched pin traces 39 in FIG. 4, the movable pins are provided with the projected pins only for the four label holding sections 24 on the movable die side. This is because the protruding pin marks 39 on the label holding section 24 which are not formed on the grain surface are relatively inconspicuous.
On the other hand, for reasons such as appearance, it is not preferable to provide a protruding pin on the bottom surface or the pedestal portion 26 in the disc storage portion 22 which is a grained surface. However, since the reverse tapered surface 35 of the outer peripheral surface of the disk holder 31 formed by the movable die is undercut in the mold opening direction A of the movable die, the movable die side Some form of mold release from is required. As this releasing means, air blow is used.

[0004] Here, an example of this type of conventional die apparatus utilizing air blow will be described with reference to FIGS. 41 is a fixed mold and 42 is a movable mold. The fixed mold 41 and the movable mold 42 move up and down with respect to each other in the drawing to open and close, and a cavity 43 having the shape of the tray 12 at the time of mold clamping.
Is formed inside. And, the fixed mold 41
Has a cavity member 44 that forms the back side of the tray 12 including the inner surface of the disk holding unit 31. On the other hand, the movable mold 42 has a core member 45 forming the front side of the tray 12, and a nest 47 for air blowing is provided in a through hole 46 formed through the core member 45 in the vertical direction in the drawing. Is embedded and fixed. This nest 47
Although the outer surface of the insert 31 is formed, the cavity surface at the upper end of the nest 47 in the drawing has a size including the entire through groove 33. In addition, a concave groove-shaped air passage is formed on the outer peripheral surface of the nest 47.
48 is formed, and the compressed air is supplied to the air passage 48 via an air passage 49 formed in the core member 45 or the like. The peripheral surface of the nest 47 and the core member
About four gaps 50 of about 0.02 mm from the air passage 48 to the cavity 43 are formed between the 45 and the peripheral surface of the through hole 46. In the conventional mold apparatus, convex portions 51 and 52 that form the through groove 33 of the disk holding portion 31 and the circular opening portion 34 are formed in the cavity member 44, and the concave portion 53 into which the convex portion 51 is fitted. Was formed in nest 47. Then, when the tray 12 is formed, the molten resin is poured into the cavity 43 from the gate while the fixed mold 41 and the movable mold 42 are clamped. Next, after the resin filled in the cavity 43 is solidified, the fixed mold 41 and the movable mold 42 are opened. At this time,
First, the tray is ejected by pushing out the ejection pin on the fixed mold 41 side.
12 is released from the fixed mold 41 side. Then, push out the protruding pin on the movable mold 42 and air blow the tray.
12 is released from the movable mold 42 side. That is, the air passage 4
Air is blown from 8, 49 to the center of the tray 12 through the gap 50 between the nest 47 and the peripheral surface of the through hole 46 of the core member 45. Leave.

[0005]

However, in the conventional mold apparatus, the projections 51 and 52 forming the through-groove 33 of the disk holding portion 31 and the circular opening 34 thereof are formed in the cavity member 44 of the fixed mold 41. As shown in FIG. 8, when the tray 12 is slightly lifted from the movable mold 42, air escapes through the through groove 33 of the disk holding portion 31, as shown by an arrow. Therefore, the air pressure is not effectively applied to the tray 12, and the disk holding unit from the movable mold 42 side is not provided.
There was a problem that the release of 31 was not performed reliably.

SUMMARY OF THE INVENTION The present invention is intended to solve such a problem, and forms a molded product having a swellable portion such as a tray of a compact disk storage case which is expandable and contractible and whose outer peripheral surface is an inversely tapered surface. It is another object of the present invention to provide a mold apparatus for releasing a bulging portion from a die member forming an outer surface of the bulging portion by air blow, so that the bulging portion is surely released.

[0007]

In order to achieve the above object, the present invention comprises a plurality of projections arranged along a circumference,
A mold device for molding a molded product having a through groove between these projections and a bulged portion having an inversely tapered surface whose outer peripheral surface gradually increases in diameter toward the tip, wherein a bulge in the molded product is provided. The first forming the back side including the inner surface of the protrusion
And a second mold member forming a front side including an outer surface of a bulging portion of the molded product, a nest is embedded in the second mold member, and a molded product is formed around the nest. In a mold device for blowing air to the mold part to release the bulge portion of the molded product from the second mold member side, the convex part forming the through groove is formed on the second mold member side including the nest. It is provided in.

[0008]

The mold device of the present invention has a through groove between a plurality of protrusions arranged along the circumference and a bulging portion having an inverse tapered surface whose outer peripheral surface gradually increases in diameter toward the tip. When molding the molded product, the back side including the inner surface of the bulging portion in the molded product is formed by the first mold member, and the front side including the outer surface of the bulging portion in the molded product is formed by the second mold member. Is done. Here, the reverse tapered surface of the outer peripheral surface of the bulging portion is undercut in the mold opening direction of the second mold member, but when the mold is opened, the molded product is separated from the first mold member side. After the mold, when releasing from the second mold member side,
Air is blown to the molded product from around the nest embedded in the second mold member to release the mold from the second mold member side while elastically deforming the bulging portion of the molded product. At this time, until the molded product is lifted up by the thickness from the second mold member side, the through groove is blocked by the convex portion on the second mold member side including the nest, so that air does not leak, Air pressure is effectively applied to the molding.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the mold apparatus according to the present invention will be described below with reference to FIGS. The mold apparatus of this embodiment is for molding the tray 12 of the compact disk storage case as described above and shown in FIGS. Reference numeral 61 denotes a fixed mold as a first mold member, and 62 denotes a movable mold as a second mold member. The fixed mold 61 and the movable mold 62 move upward and downward in the figure to open and close, and clamp. Sometimes a cavity 63 in the shape of the tray 12 is formed inside. The fixed die 61 has a cavity member 64 that forms the back side of the tray 12 including the inner surface of the disk holding unit 31. On the other hand, the movable mold 62 has a core member 65 forming the front side of the tray 12, and a nest 67 for air blowing is provided in a through hole 66 formed through the core member 65 in the vertical direction in the drawing. Is embedded and fixed. The nest 67 forms the outer surface of the disk holding portion 31, and the cavity surface at the upper end of the nest 67 in the drawing has a size including the entire through groove 33. In addition, a concave groove-shaped air passage 68 is formed on the outer peripheral surface of the nest 67, and the air passage 68 is supplied with compressed air via an air passage 69 formed in the core member 65 or the like. It has become. Between the peripheral surface of the insert 67 and the peripheral surface of the through hole 66 of the core member 65, there are formed about four gaps 70 of about 0.02 mm from the air passage 68 to the cavity 63. Further, convex portions 71 and 72 forming the through groove 33 of the disk holding portion 31 and the circular opening portion 34 thereof are formed in the insert 67.

Next, the operation of the above configuration will be described. When forming the tray 12, the fixed die 61 and the movable die 62
With the mold clamped, molten resin is poured from a gate into a cavity 63 formed between the fixed mold 61 and the movable mold 62. Next, after the resin filled in the cavity 63 is solidified, the fixed mold 61 and the movable mold 62 are opened. At this time, first, the tray 12 is released from the fixed die 61 side by the protrusion of the protrusion pin on the fixed die 61 side. Then, movable type 62
The tray 12 is released from the movable mold 62 by the protrusion of the protrusion pin on the side and air blow. That is, as shown by arrows in FIG. 1, air is blown from the air passages 68 and 69 to the central portion of the tray 12 through the nest 67 and the gap 70 between the peripheral surfaces of the through holes 66 of the core member 65. The disk holder 31 separates from the movable mold 62 while being elastically deformed. In this manner, the disk holding portion 31 whose outer peripheral surface has an undercut reverse taper surface with respect to the mold opening direction of the movable mold 62 is forcibly removed by air blow. At this time, as shown in FIG. 1, the through-groove 33 and the circular opening 34 are nested 67 until the tray 12 rises from the movable mold 62 by the thickness thereof.
The space 73 formed between the cavity surface of the movable mold 62 and the tray 12 is shielded from the outside air. Therefore, the tray from the movable mold 42
Until the 12 rises by its thickness, the air flowing out of the gap 70 around the nest 67 to the space 73 and blowing on the tray 12 does not escape to the outside air 74, and the air pressure is effectively applied to the tray 12. As a result, the disk holding unit is moved from the movable mold 62 side.
31 can be surely released.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made. For example,
In the above-described embodiment, the nest 67 is formed such that the cavity surface thereof has a through groove.
6 and 7, the nest 67 may be of a small diameter forming only the central portion of the disk holding portion 31, as shown in FIGS. In this case, the through groove 33 between the tips of the hook-shaped protrusions 32 and the convex portions 71 and 72 forming the circular opening 34 are formed in the nest 67 while the through groove 33 is formed.
Is formed on the core member 65. Further, in the above-described embodiment, the molding of the tray 12 of the compact disk storage case has been described as an example.However, the present invention has a through groove between a plurality of protrusions arranged along the circumference, and the outer peripheral surface faces the front end. The present invention can be generally applied to a molded article having a bulging portion having an inversely tapered surface whose diameter gradually increases.

[0012]

According to the present invention, like a tray of a compact disk storage case, a bulging portion having a through groove between a plurality of projections arranged along the circumference and having an outer peripheral surface forming an inversely tapered surface is provided. A first mold member forming a back side including an inner surface of a bulge portion of the molded product, and a second mold member forming a front side including an outer surface of the bulge portion in the molded product. In a mold apparatus in which a nest is embedded in the second mold member, air is blown from around the nest to the molded product to release the bulge portion from the second mold member side. By providing the protruding portion to be formed on the second mold member side including the nest, when the bulging portion is released from the mold by air blow, the molded product rises by the thickness from the second mold member side. Until the through groove is closed by the convex part In not leak air, the air pressure is applied to enable the molded article, therefore, it is possible to reliably release the bulging portion from the second mold member side.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a mold apparatus of the present invention;
The state at the time of mold release is shown.

FIG. 2 is a cross-sectional view taken along a plane passing through a protrusion of a disk holding portion as a bulging portion.

FIG. 3 is a cross-sectional view taken along a plane passing through a through groove of the disk holding unit.

FIG. 4 is a perspective view of a compact disk storage case.

FIG. 5 is a perspective view of a tray of the compact disk storage case.

FIG. 6 is a cross-sectional view showing another embodiment of the mold apparatus of the present invention, in which a surface passing through a projection of the disk holding portion is a cross section.

FIG. 7 is a cross-sectional view taken along a plane passing through a through groove of the disk holding unit.

FIG. 8 is a cross-sectional view showing an example of a conventional mold apparatus, showing a state at the time of mold release.

FIG. 9 is a cross-sectional view taken along a plane passing through a protrusion of the disk holding unit.

FIG. 10 is a cross-sectional view taken along a plane passing through a through groove of the disk holding unit.

[Explanation of symbols]

 12 Tray (molded product) 31 Disk holding part (bulging part) 32 Hook-shaped projection (projection) 33 Through groove 35 Reverse taper surface 61 Fixed die (first die member) 62 Movable die (second die member) ) 67 nesting 71 convex part 72 convex part 76 convex part

Claims (1)

(57) [Claims] 1. A method comprising: a plurality of protrusions arranged along a circumference;
A mold device for molding a molded product having a through groove between these projections and a bulged portion having an inversely tapered surface whose outer peripheral surface gradually increases in diameter toward the tip, wherein a bulge in the molded product is provided. The first forming the back side including the inner surface of the protrusion
And a second mold member forming a front side including an outer surface of a bulging portion of the molded product, a nest is embedded in the second mold member, and a molded product is formed around the nest. In a mold device for blowing air to the mold part to release the bulge portion of the molded product from the second mold member side, the convex part forming the through groove is formed on the second mold member side including the nest. A mold device provided in a mold.