JP2001180778A - Storage case for disks and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of defects in forming such as warps, weld lines and others for a lid of a CD storage case. SOLUTION: Recessed thinned sections 46 are formed on the inner faces of side wall sections 33 of a lid 12. The sections 46 are extended from a position along the inner face of a base section 31 to the end edges of side wall sections 33. The thinned sections 46 are formed on the positions in the vicinity of both sides of protruded piece sections 37 on central sections of side wall sections 33 and separating away from the protrusion sections 37. In forming, the resin flow is prevented by the thinned sections 46 to prevent the generation of weld lines on the base section 31. After forming, the force for shrinking the wide wall sections is divided into sections by the sections 46 to prevent the generation of warps.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk storage case for storing disks such as a compact disk (hereinafter referred to as a CD) and a digital video disk (hereinafter referred to as a DVD) and a method of manufacturing the same.

[0002]

A CD storage case for storing a CD therein is constituted by a bottom as a bottom member and a lid as a lid member which are rotatably opened and closed with each other. Each of the bottom and the lid is an integrally molded article of a thermoplastic resin such as transparent polystyrene.

FIG. 13 shows an example of a conventional lid 1. The CD is held at the bottom (not shown), and the lid 1 covers the CD held at the bottom. The lid 1 includes a rectangular substrate portion 2 positioned in parallel with the stored CD, an elongated base end wall portion 3 bent substantially at right angles from one edge of the base portion 2, and a base end wall portion. And a pair of elongated side walls 4 bent at substantially right angles in the same direction as the base wall 3 from the two edges sandwiching the side 3. One end of the side wall portion 4 on the side of the base end wall portion 3 is a bearing piece 5 for pivoting to the bottom. A pair of label holding pieces 6 are formed on the inner surface of the side wall 4, and through holes 7 are formed between the label holding pieces 6 and the substrate 2. These through holes 7
Are necessary for forming the label holding piece 6.
And in the conventional lid 1, the thickness of the side wall part 4 is:
Except for a part of the label holding piece 6, the through hole 7, and the bearing piece 5, the whole was basically uniform.

In the molding of the lid 1, although not shown, a mold having a fixed mold and a movable mold that can be opened and closed is used, and the mold is closed to form the lid 1 between the fixed mold and the movable mold. A cavity is formed, and the cavity is filled with molten resin from a single gate. The position of the gate is set at a position corresponding to the center of the edge of the substrate 1 opposite to the base wall 3.
In FIGS. 13 and 14, reference numeral 8 denotes a gate mark.

However, the lid 1 of the conventional CD storage case has the following problems. First, due to shrinkage of the resin after molding, particularly shrinkage of the side wall portion 4, the side wall portion 4 is likely to be warped as shown by a chain line in FIG. In particular, when the molding cycle is shortened to improve the productivity, the molded lid 1 is taken out of the mold before being sufficiently cooled and contracted, so that the deformation due to the contraction becomes larger. For example, in a storage case for a CD-R, which can be written only once, the molding cycle must be shortened for mass production, so deformation due to shrinkage becomes even more problematic. Further, the film packaging is performed on the CD storage case. At the time of the film packaging, the film material is shrunk and adhered to the outer surface of the CD storage case.
If the film has a warp, the warp tends to be further expanded by the force of shrinking the film material. And lid 1
Warp results in poor stability when stacked at a store or the like, and also makes it inconvenient for a general user to store or the like.

One means for preventing the warpage is:
The reason is that the thickness of the substrate portion 2 is increased so that deformation is less likely to occur.
However, increasing the thickness of the substrate portion 2 is against the demand for weight reduction.

At the time of molding, the resin flowing from the gate at the edge of the substrate portion 2 opposite to the base end wall portion 3 is:
As shown by an arrow A in FIG. 14, a portion corresponding to the substrate portion 2 in the cavity spreads toward the base end wall portion 3.
Some resin flows into a portion corresponding to the side wall portion 4 and flows there. In the recent lid 1, the thickness of the substrate 1 is set to be as thin as 1.1 mm, for example, in order to reduce the weight.
For example, it is set to be 1.4 to 1.5 mm thicker than the substrate portion 1.
Therefore, the flow resistance in the portion corresponding to the substrate portion 4 in the cavity is large. Therefore, on the base wall 3 side,
The resin flowing through the side wall portion 4 is moved earlier than the resin flowing through the portion corresponding to the substrate portion 2 reaches the side wall portion 4.
Flow into Therefore, the resin flowing in the substrate portion 2 and the resin flowing from the side wall portion 4 merge into the substrate portion 2, and as a result, a weld line 9 is generated in the substrate portion 2 along the side wall portion 4. Since the weld line 9 is formed on the substrate portion 2 that is easily visible to the user, the appearance of the CD storage case as a product is impaired. The weld line 9 is a place where the strength is weak. However, as described above, since the substrate portion 2 itself is wider and thinner and has a weaker strength, the lid 1 is easily damaged.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a disk storage case capable of preventing occurrence of molding defects such as warpage and weld lines, and a method of manufacturing the same.

[0009]

According to a first aspect of the present invention, there is provided a lid member comprising a resin molded article having a substrate portion and an elongated wall portion bent from an edge of the substrate portion. In the case of a disk storage case provided with the above, a concave-shaped recessed portion is formed in a wall portion of the lid member, and the recess portion extends to a leading edge of the wall portion.

[0010] Even if the lid material shrinks after molding due to the presence of the fleshy portion, the force to shrink in the wall portion is divided by the fleshy portion, and the wall portion is warped by the shrinkage. Is prevented from being deformed. Also, during molding, the flow of the resin in the portion corresponding to the wall portion in the cavity in the mold is hindered in the portion corresponding to the thinned portion, so that the portion corresponding to the wall portion in the cavity corresponds to the substrate portion. The resin is prevented from sneaking into the portion where the resin flows, and the resin flows from the portion corresponding to the substrate to the portion corresponding to the wall. This prevents a weld line from being generated in the substrate portion.

According to a second aspect of the present invention, in the disk storage case according to the first aspect of the present invention, the thinned portion is formed on an inner surface of the wall.

In particular, when film packaging is performed on the outer surface of the disk storage case, if the outer surface of the lid member has a concave meat-thinned portion, the film material may be thinned when a heater is applied to the film material from outside during packaging. There is a possibility that the welding may escape into the portion and the welding may not be reliably performed, or the film material may be damaged. However, such a problem can be avoided by forming the underfill portion on the inner surface of the wall portion.

According to a third aspect of the present invention, in the disk storage case according to the second aspect of the present invention, the wall portion has a protruding portion having a height dimension larger than that of an adjacent portion at a central portion in the longitudinal direction. The fleshy portion is formed in the vicinity of both sides of the projecting piece and at a position off the projecting piece.

The protruding piece is inserted into a notch at the edge of the bottom material to which the lid is pivotally attached, for example. In this case, the flesh-filled portion communicates between the inside and the outside of the disc storage case, so that there is a possibility that dust may enter the disc-like storage case via the flesh-filled portion during use. On the other hand, if there is a fleshy portion at a position separated from the projecting portion, it is possible to prevent dust from entering the disc storage case. Further, in order to enhance the effect of preventing the warp and the occurrence of the weld line, it is preferable that the underfill is located as close to the center in the longitudinal direction of the wall as possible. , The meat-thinned portion can be positioned as close to the longitudinal center of the wall as possible.

According to a fourth aspect of the present invention, in the disk storage case according to the second or third aspect, the underfill portion extends from a position along an inner surface of the substrate portion to a leading edge of the wall portion. It is.

[0016] Thereby, the force of shrinking the wall portion after molding can be surely divided by the slackened portion.
The effect of preventing the flow of the resin in the portion corresponding to the wall portion in the cavity and preventing the occurrence of the weld line in the substrate portion can be obtained more reliably.

According to a fifth aspect of the present invention, in the disk storage case according to the fourth aspect of the present invention, a base end of the recess is extended to a position deeper than an inner surface of the substrate.

Thus, the force of shrinking the wall portion after molding can be more reliably divided by the thinned portion, and the flow of resin in the portion corresponding to the wall portion in the cavity is obstructed and the weld line is formed on the substrate portion. The effect of preventing the occurrence of phenomena can be obtained even more reliably.

According to a sixth aspect of the present invention, in the disk storage case according to any one of the second to fifth aspects, the depth of the thin portion in the thickness direction of the wall portion is equal to the thickness of the wall portion. Is 1/2 or more.

Thus, the force of shrinking the wall after molding can be surely divided by the slackened portion.
The effect of preventing the flow of the resin in the portion corresponding to the wall portion in the cavity and preventing the occurrence of the weld line in the substrate portion can be obtained more reliably.

According to a seventh aspect of the present invention, there is provided the method of manufacturing a disk storage case according to any one of the first to sixth aspects, wherein a plurality of molds are closed and the lid is formed between the molds. Is formed, the cavity is filled with resin to form the lid, and at the time of this molding, the underfill is formed by nests removably provided on one of the molds. .

In order to surely obtain the effect of preventing the occurrence of the warp and the weld line and to prevent the occurrence of breakage or molding failure due to the excessively large thickness of the underfill, the size and position of the underfill must be appropriately adjusted. It is necessary to set. However, if the fleshy portion is formed by the detachably provided nest as in the invention of claim 7, the size and position of the flesh-thin portion can be adjusted by removing or replacing the nest once. Can be relatively easy.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a disk storage case and a method of manufacturing the same according to the present invention will be described below with reference to the drawings. The disk storage cases of the present embodiment are all CD storage cases. 1 and 2 show a first embodiment of the storage case. A storage case for storing a CD (not shown) therein includes a bottom 11 as a bottom material and a lid 12 as a lid material that are rotatably opened and closed with each other. Each of the bottom 11 and the lid 12 is an integrally molded article of a thermoplastic resin such as transparent polystyrene. The storage case of the present embodiment does not have a tray, and includes only the bottom 11 and the lid 12.

The bottom 11 is for holding a CD in a detachable manner, and has a rectangular substrate portion 16 positioned in parallel with the CD.
And the same direction (upward) from the four edges of the substrate portion 16
It has an elongated base end wall portion 17 bent substantially at right angles, a pair of first side wall portions 18, a pair of second side wall portions 19, and a front end wall portion 20. The base wall 17 is located on one side connected to the lid 12, the tip wall 20 is located on the opposite side, and the side walls 18, 19 are located on the remaining two sides. is there. The first side wall 18 is connected to the base wall 17, and the second side wall 19 is connected to the front end wall 20.
An important notch portion 21 is formed between the side wall portion 19 and the side wall portion 19 to make it easier to put a finger on the stored CD. The dimension A between the two important notches 21 is substantially equal to the outer diameter (120 mm) of the CD. The board portion 16 projects slightly outward from the side wall portions 18 and 19, and the projecting portion forms the lid receiving portion 22. In addition, small notches 23 are formed in the center of the front edge (upper edge) of the first side wall 18 and the second side wall 19 opposite to the substrate 16. The first side wall portion 18 has an arm portion 24 whose end on the base end wall portion 17 side projects beyond the base end wall portion 17, and a support shaft portion 25 is provided on an outer surface of the arm portion 24. Are formed to protrude. A concave lid engaging portion 26 is formed at a position near the important notch 21 on the outer surface of the first side wall portion 18. Further, a CD holding portion 27 is formed on the inner surface of the substrate portion 16 so as to be detachably engaged with the center hole of the CD, and a plurality of arc-shaped protrusions located on the outer peripheral side of the stored CD. Article 28 is formed.

The lid 12 has a rectangular substrate portion 31 positioned parallel to the stored CD, an elongated base end wall portion 32 bent substantially at right angles from one edge of the substrate portion 31, It has a pair of elongated side walls 33 bent at substantially right angles in the same direction as the base wall 32 from two edges sandwiching the side of the base wall 32. Further, at the end of the substrate portion 31 on the side of the base wall portion 32, a cut groove portion 34 is formed along the side wall portion 33, whereby the end of the side wall portion 33 on the side of the base wall portion 32 is formed. The bearing piece 35 is provided. And these bearing pieces
In 35, a bearing hole 36 is formed in which the support shaft 25 of the bottom 11 is pivotally connected. The central portion in the longitudinal direction of the side wall portion 33 is a protruding portion having a height dimension larger than that of the adjacent portion.
It is 37. In other words, the center of the leading edge (upper edge) of the side wall 33 opposite to the substrate 31 is the bottom 11.
The projection 37 is inserted into each of the important notches 21. Note that a part of the bearing piece 35 is also at the same height as the protruding piece 37. A pair of label pressing pieces 38 are formed on the inner surface of the side wall 4 at both sides of the protruding piece 37, respectively.
Through holes 39 are formed in portions between the two. On the inner surface of the substrate portion 31, a label pressing ridge 40 is formed at an end edge opposite to the base end wall portion 32. Furthermore, on the inner surface of the side wall 4, a position on the base end wall 32 side of the protruding piece 37 is
Engagement protrusions 41 are respectively formed to be engaged with both lid locking portions 26 of the bottom 11.

On the inner surfaces of both side walls 33 of the lid 12, concave concave portions 46 are formed near the both sides of the projecting portion 37 and at positions off the projecting portion 37, respectively.
As shown in detail in FIG. 2, these recesses 46 extend from positions along the inner surface of the substrate 31 to the leading edge of the side wall 33, and escape to the leading edge. Further, while the thickness t1 of the side wall portion 33 is 1.4 to 1.5 mm, the maximum depth t2 of the thin portion 46 in the direction of this thickness t1 is about 0.8 to 0.9 mm, and the side wall portion is The thickness is less than half of the thickness t1 of 33.

When the bottom 11 and the lid 12 are rotated and closed, the leading edge of the side wall 33 of the lid 12 abuts on the lid receiving portion 22 of the bottom 11, and the projection of the side wall 33 of the lid 12 is made. The piece 37 enters the important notch 21 of the bottom 11, and the label pressing piece 38 of the side wall 33 of the lid 12 is the side wall of the bottom 11.
After entering the small notch portions 18 and 19, the engaging projections 41 of the side wall portion 33 of the lid 12 engage with the lid engaging portions 26 of the side wall portion 18 of the bottom 11.

Next, the construction of a mold apparatus for injection-molding the lid 12 will be described with reference to FIGS.
51 is a fixed type and 52 is a movable type.
And the movable mold 52 are arranged in the vertical direction in FIG.
(Referred to as the mold opening / closing direction) to open and close, and when the mold is closed, a cavity 53 having the shape of the lid 12 is formed therebetween. The mold opening / closing direction is set to a direction orthogonal to the substrate 31 of the lid 12, and the fixed mold 51 is basically
The movable mold 52 forms the inner surface of the lid 12.

The fixed mold 51 includes a fixed mold plate 56 and a cavity member 57 fixed to the fixed mold plate 56 to form the cavity 53. Further, the fixed mold 51 has a gate 58 for injecting a resin as a molding material into the cavity 53. There is only one gate 58 for one cavity 53, and the gate 58 opens at a position corresponding to the center of the edge of the substrate portion 31 of the lid 12 opposite to the base wall portion 32. In FIG. 1, reference numeral 58a denotes a gate mark.

The movable mold 52 includes a movable mold plate 61 and a core member 62 detachably fixed to the movable mold plate 61 to form a cavity 53. The movable mold plate 61 and the core member 62 are fixed to a movable receiving plate 63. The slide core 64 is incorporated in the movable receiving plate 63 so as to be movable in a direction orthogonal to the side wall 33 of the lid 12. The slide core 64 forms the bearing hole 36, the label pressing piece 38, and the through hole 39 of the side wall 33 including the outer surface of the side wall 33. The slide core 64 has an inclined hole 65.
And an inclined surface 66 are formed. On the other hand, the fixed mold 51
Is fixed to an inclined pin 67 which is removably inserted into an inclined hole 65 of a slide core 64, and a locking block which abuts against an inclined surface 66 of the slide core 64 when the mold is closed.
68 is fixed. The movable die 52 is provided with a protruding pin 69 for releasing the molded lid 12 from the mold. These protruding pins 69 are provided at positions corresponding to the side wall portions 33 of the lid 12 so that the marks do not impair the appearance.

Further, a plurality of nests 71 forming the recesses 46 of the side walls 33 of the lid 12 are detachably fixed to the movable mold 52. These inserts 71 have a substantially elongated rectangular rod shape, and one side thereof is fitted in a concave groove 72 formed on a side surface of the core member 62 and extending in the mold opening and closing direction. A flange 73 is formed at the base end of the nest 71 abutting against the movable receiving plate 63. And nesting 71,
The movable side receiving plate 63 and the core member by the movable side mold plate 61
Fixed to 62. For that purpose, the movable mold plate 61
Has a concave portion 76 that fits into the flange portion 73 of the insert 71. Further, the movable mold plate 61 itself is detachably fixed to the movable-side receiving plate 63 by bolts 77.
Is fixed by being sandwiched between the core member 62 and the movable mold plate 61. Then, move the movable mold plate 61 to the movable receiving plate.
By removing it from 63, the nest 71 can also be removed.

As shown in FIG. 6 to FIG.
An appropriate draft angle is set in the meat-thickness forming portion 78 forming the meat-thickness portion 46 in FIG. In addition, an appropriate curvature is set at a corner of the meat-thickness forming portion 78.

Next, injection molding of the lid 12 using the above-described mold apparatus will be described. First, the fixed mold 51 and the movable mold 52 are closed, and a cavity 53 is formed between the fixed mold 51 and the movable mold 52. With the closing of the mold, the inclined pin 67 of the fixed mold 51 is inserted into the inclined hole 65 of the slide core 64 of the movable mold 52, whereby the slide core 64 moves in a direction approaching the core member 62. Eventually, the locking core 68 of the fixed mold 51 abuts against the inclined surface 66 of the slide core 64, so that the slide core 64 is held at a predetermined position.

Then, the molten resin is injected from the gate 58 into the cavity 53. In the cavity 53, the resin first spreads a portion corresponding to the substrate portion 31 of the lid 12, further flows into a portion corresponding to the side wall portion 33, a portion corresponding to the base end wall portion 32, and flows into the entire cavity 53. Will be filled. When the resin flows through the portion corresponding to the side wall portion 33,
The flesh-thickening forming portion 78 of the nest 71 forms a convex portion in a portion corresponding to the side wall portion 33, and thus obstructs the flow of the resin. Therefore, even on the side of the base end wall portion 32 away from the gate 58, the side wall portion
Before the resin flowing through the portion corresponding to 33 goes around to the portion corresponding to substrate portion 31, the resin flowing through the portion corresponding to substrate portion 31 goes around to the portion corresponding to side wall portion 33. That is, the resin flowing in the portion corresponding to the substrate portion 31 and the resin flowing in the portion corresponding to the side wall portion 33 are not the substrate portion 31 but the corners between the substrate portion 31 and the side wall portion 33. Alternatively, they merge at the side wall 33. Therefore, even if a weld line is generated, the weld line is formed at a corner between the substrate portion 31 and the side wall portion 33 or at the side wall portion 33.

Further, after the resin filled in the cavity 53, ie, the lid 12, is cooled to some extent and solidified, the fixed mold 51 and the movable mold 52 are opened. At the start of this mold opening, the molded lid 12 is first fixed
Moves away from 51 and stops on the movable mold 52. When the mold is opened, the inclined pins 67 of the fixed mold 51 slide in the inclined holes 65 of the slide core 64 on the movable mold 52 side, so that the slide core 64 moves outward from the side wall 33 of the lid 12. And passes through the bearing hole 36 and the through hole 39 of the side wall 33. afterwards,
When the protruding pins 69 protrude the lid 12, the lid 12 is separated from the core member 62, and the lid 12 is taken out of the mold.

Thereafter, the mold is closed again, and the above molding cycle is repeated.

The thermoplastic resin generally shrinks due to solidification by cooling, but if the mold is in a closed state, it is possible to compensate for the shrinkage of the resin by holding pressure. Since the lid 12 is regulated by the mold, deformation of the lid 12 can be prevented. However, particularly when the molding cycle is shortened to improve productivity, the lid 12 is taken out before cooling sufficiently, so that deformation due to shrinkage is likely to occur. Furthermore, when the substrate portion 31 is made thinner for weight reduction, the shape retaining force of the substrate portion 31 is weakened, and the side wall portion 33 of the lid 12 is likely to be warped due to shrinkage.

However, in the above-described embodiment, since the recess 12 is formed in the side wall 33, even if the lid 12 taken out of the mold after the molding is contracted, the side wall 33 contracts. Since the force to be cut is divided by the thinned portion 46, the side wall 33 is prevented from being deformed due to shrinkage, in particular, warpage.

The lid 12 thus formed is combined with the separately formed bottom 11 to form a CD storage case. Further, if necessary, a label is incorporated, a CD is stored in the bottom 11, and a film is wrapped on the outer surface of the CD storage case to obtain a product.

Here, the film packaging will be described. In this film packaging, as shown in FIG.
The film material 81 is put on the CD storage case, and the heater 82 is pressed against the edge of the overlapped film material 81 from the outside, so that the edge of the overlapped film material 81 is welded. This welded portion 83 is usually on the outer surface of the walls 20, 32, 33 of the bottom 11 and the lid 12. In some cases,
Heating causes the film material 81 to shrink and adhere to the outer surface of the CD storage case.

As described above, according to the configuration of the above embodiment,
The lid 46 is excellent in quality because it can prevent deformation such as warpage and occurrence of molding defects such as weld lines, etc.
12, and can provide a CD storage case. Prevention of warpage brings advantages such as improvement in stability when CD storage cases are stacked at a store or the like and improvement in usability when used by general users. Further, as described above, the film material 81
When the CD storage case is film-wrapped by shrinking the CD storage case, it is possible to prevent the warpage from expanding. Also, the substrate part 31
Can prevent the occurrence of weld lines
This has the effect of improving the appearance and preventing the lid 12 from being damaged.

Further, the underfill portion 46 extends from a position along the inner surface of the substrate portion 31 on the inner surface of the side wall portion 33 to the leading edge of the side wall portion 33. The depth t2 of the underfill portion 46 is Since the thickness t1 of the portion 33 is set to １ ／ or more, the force of the side wall portion 33 to shrink after molding can be surely divided by the thinned portion 46, and at the portion corresponding to the side wall portion 33 in the cavity 53. The effect of preventing the flow of the resin and the generation of the weld line in the substrate portion 31 can be obtained more reliably.

The provision of the underfill 46 on the inner surface of the side wall 33 has the following advantages. As mentioned above, C
When the D storage case is film-wrapped, there is a concave portion on the outer surface of the CD storage case, and the concave portion is a welded portion of the film material 81.
When it is located at 83, when the heater 82 is applied to the film material 81 from the outside at the time of packaging, the film material 81 escapes into the concave portion, welding is not reliably performed, or the film material 81 is damaged. However, such a problem can be avoided by forming the concave portion 46 having a concave shape on the inner surface of the side wall portion 33.

Further, assuming that the concave portion 46 formed on the inner surface of the side wall portion 33 is located at the projecting portion 37 at the center of the side wall portion 33, the projecting portion 37 is 12 is inserted into the important notch 21 of the bottom 11 in a state in which the bottom 12 is closed, so that the meat thin portion 46 communicates with the inside and outside of the CD storage case, and dust enters the CD storage case via the meat thin portion 46. May invade. On the other hand, in the above-described embodiment, since the underfill portion 46 is provided at a position deviated from the protruding piece portion 37, the distal end opening of the underfill portion 46 is closed by the lid of the bottom 12 with the bottom 11 and the lid 12 closed. Since it is closed by the receiving portion 22, dust can be prevented from entering the CD storage case.

In order to enhance the effect of preventing the occurrence of the warp and the weld line, it is preferable that the underfill portion 46 is located as close to the longitudinal center of the side wall portion 33 as possible.
By locating the flesh-thinned portions 46 near both sides of the protruding piece 37, the flesh-thinned portions 46 can be positioned as close to the longitudinal center of the side wall 33 as possible.

Further, the concave meat-slack portion 46 is formed on the side wall portion 33.
Since the opening is formed at the leading edge opposite to the substrate portion 31 in the above, the underfill portion 46 does not form an undercut during molding, and the underfill portion 46 can be formed without any trouble.

In addition, according to the method of manufacturing the lid 12, since the fleshy portion 46 is formed by the nest 71 which is detachably provided on the movable mold 52, the nest 71 may be once removed or the size may be reduced. By replacing it with a different one,
Adjustment of the size and position of the meat sunk portion 46 can be relatively easily performed. In other words, in order to reliably obtain the effect of preventing the occurrence of warpage and weld lines as described above, and to prevent the occurrence of breakage or molding failure due to the excessively large thickness of the underfilled portion 46, the size of the underfilled portion 46 must be reduced. Although it is necessary to set the position appropriately, the size and position of the flesh-filled portion 46 can be easily adjusted by forming the flesh-filled portion 46 with the detachable inserts 71.

Further, the CD storage case of the above embodiment is
Since a CD is held on the bottom 11 itself without using a tray separate from the bottom 11, the entire CD storage case can be made thin.

FIG. 9 shows a second embodiment of the CD storage case of the present invention. In the lid 12 of the second embodiment, the thinner portion 46 is also provided on the inner surface of the side wall portion 33, but the base end of the thinner portion 46 is extended to a position deeper than the inner surface of the substrate portion 31. . In other words, the base end of the undercut portion 46 forms a concave portion 86 in the substrate portion 31.

Thus, the force of shrinking the side wall portion 33 after molding can be more reliably divided by the thinned portion 46, and the flow of resin in the portion of the cavity 53 corresponding to the side wall portion 33 is obstructed. The effect of preventing a weld line from being generated in the portion 31 can be obtained more reliably.

FIG. 10 shows a third embodiment of the CD storage case according to the present invention.
It shows an embodiment. In the lid 12 according to the third embodiment, a concave recess 87 is formed in a wide area on the inner surface of the side wall 33 except for both ends thereof. Side wall part 33
Because the inner surface of the bottom 11 covers the outside of the side wall portions 18 and 19 of the bottom 11, the strength of the product is reduced and the bottom 11
The entire side wall 33 cannot be made thinner, for example, because the gap between the side wall 33 and the backlash becomes large, and it is not preferable to form a thinned portion on the inner surface of the bearing piece 35 in particular. In addition, the outer dimensions of the CD storage case are half standardized. Therefore, the structure is such that the recesses 87 are formed only on the inner surface of the side wall 33, and the recesses 87 are not formed on both ends of the inner surface of the side wall 33.

FIG. 11 shows a fourth embodiment of the CD storage case according to the present invention.
It shows an embodiment. Lid 12 of this fourth embodiment
Is formed by forming a concave-shaped recessed portion 88 on the outer surface of the side wall portion 33. The lightening portion 88 is also open to the front end edge of the side wall portion 33 on the side opposite to the substrate portion 31, so that the lightening portion 88 can be easily formed when the lid 12 is formed. Thus, if the fleshy portion 88 is provided on the outer surface of the side wall portion 33, dust enters the CD storage case via the fleshy portion 88 even if the fleshy portion 88 is provided on the protruding piece portion 37. No problem.

FIG. 12 shows a fifth embodiment of the CD storage case of the present invention.
It shows an embodiment. Lid 12 of the fifth embodiment
Is formed in a portion of the side wall portion 33 opposite to the substrate portion 31 with a concave-shaped recessed portion 90 penetrating from the inner surface to the outer surface. In this case, it is preferable that the lid receiving portion 22 of the bottom 11 be formed with a convex portion 91 that enters the underfill 90 when the bottom 11 and the lid 12 are closed together.

Note that the present invention is not limited to the above-described embodiment, and various modifications can be made. For example,
The position, the size, and the number of the flesh-filled portions can be appropriately set in addition to the above embodiments. Generally, if the underfill is provided at a position far away from the gate, that is, at a position closer to the bearing piece, the effect of preventing the occurrence of a weld line in the substrate becomes weaker. It is better to provide it near the center of the part. Although the disk storage case of the above embodiment is a CD storage case, the present invention can be applied to a DVD storage case and the like.

Further, the configuration of the mold apparatus for forming the undercut portion is not limited to that of the above embodiment. For example, in the above-described embodiment, the fleshy portion 46 is formed by using the nest 71, but a convex portion for forming the fleshy portion may be formed integrally with the core member. Further, it is also possible to form a fleshy portion using a protruding pin. Further, in the case where the thinner portion is formed on the outer surface of the side wall portion as in the fourth embodiment, the thinner portion can be formed by the slide core.

[0056]

According to the first aspect of the present invention, in the disk storage case provided with a lid member made of a resin molded product having a substrate portion and an elongated wall portion bent from an edge of the substrate portion, Since the concave wall portion of the lid material is formed with a concave recessed portion that penetrates to the edge of the wall portion, it is possible to prevent the occurrence of molding defects such as warpage and weld lines, and to provide a high-quality disk storage case. .

According to the disk storage case of the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, since the thinned portion is formed on the inner surface of the wall, for example, the desk storage case of Even when film packaging is performed on the outer surface, it is possible to prevent inconveniences such as a portion where welding is not reliably performed in the film material and the film material being damaged.

According to the disk storage case of the third aspect of the invention, in addition to the effect of the second aspect of the invention, the wall portion is
A protruding portion having a height dimension larger than that of the adjacent portion is provided at a central portion in the longitudinal direction, and the underfill is formed at a position near both sides of the protruding portion and separated from the protruding portion. Therefore, for example, even if the protruding portion is inserted into the cutout portion at the edge of the bottom member to which the lid member is pivotally attached, dust enters the disk storage case through the recessed portion. Can be prevented, and the effect of preventing the occurrence of warpage and weld lines due to the thinned portions can be exhibited as much as possible.

According to the disk storage case of the fourth aspect of the present invention, in addition to the effects of the second or third aspect of the present invention, in addition to the effect of the second aspect of the present invention, the thinned portion is provided at an end of the wall portion from a position along the inner surface of the substrate portion. Since it extends to the edge, it is possible to further enhance the effect of preventing the occurrence of warpage and weld lines due to the recessed portions.

According to the disk storage case of the fifth aspect, in addition to the effect of the fourth aspect, in addition to the effect of the fourth aspect, the base end of the underfill portion extends to a position deeper than the inner surface of the substrate portion. Therefore, it is possible to further enhance the effect of preventing the occurrence of warpage and weld lines due to the slack portion.

According to the disk storage case of the sixth aspect of the invention, in addition to the effect of any one of the second to fifth aspects, the depth of the thin portion in the thickness direction of the wall is: Since the thickness is equal to or more than の of the thickness of the wall portion, the effect of preventing warpage and weld lines from occurring due to the thinned portion can be further enhanced.

According to a seventh aspect of the present invention, there is provided the method of manufacturing a disk storage case according to any one of the first to sixth aspects,
After closing a plurality of molds and forming a cavity in the shape of the lid between the molds, the cavity is filled with resin to form the lid, and at the time of molding, one of the molds is formed. Since the fleshy portion is formed by nests which are detachably provided on one, the size and position of the fleshy portion can be relatively easily adjusted at the time of molding, and the effect of preventing warpage and weld lines due to the flesh-thin portion can be prevented. Can be obtained accurately.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a disk storage case of the present invention.

FIG. 2 is a cross-sectional view showing the vicinity of a meat-slack portion of the same.

FIG. 3 is a cross-sectional view showing the same film packaging.

FIG. 4 is a sectional view of a mold device for molding the lid.

FIG. 5 is a side view of a core member of the mold apparatus.

FIG. 6 is an enlarged view of the vicinity of the nest shown in FIG. 4;

FIG. 7 is an enlarged view of the vicinity of the nest shown in FIG. 5;

FIG. 8 is a plan view showing the vicinity of the telescopic member.

FIG. 9 is a sectional view showing a second embodiment of the disk storage case of the present invention.

FIG. 10 is a plan view showing a third embodiment of the disk storage case of the present invention.

FIG. 11 is a sectional view showing a fourth embodiment of the disk storage case of the present invention.

FIG. 12 is a sectional view showing a fifth embodiment of the disk storage case of the present invention.

FIG. 13 is a perspective view of a lid showing an example of a conventional disk storage case.

FIG. 14 is a perspective view illustrating a problem of a weld line according to the embodiment.

[Explanation of symbols]

 12 Lid (lid material) 31 Board part 33 Side wall part (wall part) 37 Protrusion part 46 Slack part 51 Fixed type (mold) 52 Movable type (mold) 53 Cavity 71 Nest 87 Filler part 88 Filler part Part 90 Thickness t1 Side wall thickness t2 Thickness

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshinori Higuchi 3-1-1 Koganecho, Niigata City, Niigata Prefecture Inside Mitsubishi Materia Real Co., Ltd. (72) Inventor Hiroki Honma 3-1-1 Koganemachi, Niigata City, Niigata Mitsubishi Materia Inside Niigata Manufacturing Co., Ltd. (72) Inventor Yu Ikebe 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Corporation (72) Inventor Kimitoshi Ito 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Corporation (72) Inventor Yoshiyuki Okada 1-6-1 Nihonbashi Honishi-cho, Chuo-ku, Tokyo Asahi Nippon Sangyo Co., Ltd. F-term (reference) 3E036 AA05 CA01 FA01 FB01

Claims (7)

[Claims] 1. A disk storage case provided with a lid member made of a resin molded product having a substrate portion and an elongated wall portion bent from an edge of the substrate portion.
A disc storage case, wherein a recessed recessed portion is formed to extend to a leading edge of the wall. 2. The disk storage case according to claim 1, wherein the wall portion is formed on an inner surface of the wall. 3. The wall portion has a protruding portion having a height dimension larger than that of an adjacent portion at a central portion in the longitudinal direction. 3. The disk storage case according to claim 2, wherein the disk storage case is formed at a position deviated from the one part. 4. The disk storage case according to claim 2, wherein the underfill portion extends from a position along an inner surface of the substrate portion to a leading edge of the wall portion. 5. The disk storage case according to claim 4, wherein a base end of the underfill portion extends to a position deeper than an inner surface of the substrate portion. 6. The thickness of the wall portion in the thickness direction of the wall portion is less than or equal to 厚 of the thickness of the wall portion. Disc storage case described in. 7. The method for manufacturing a disk storage case according to claim 1, wherein a plurality of molds are closed, and a cavity having the shape of the lid is formed between the molds. After forming, the cavity is filled with resin to mold the lid, and at the time of this molding, the meat-slack portion is formed by a nest that is detachably provided on one of the molds. Manufacturing method of disc storage case.