JP2003340874A - Method for forming storage case - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming a storage case in which a weld line is not appeared at the corresponding place of a hinge for opening and closing and also a cycle can be increased. <P>SOLUTION: The method for forming the storage case comprises that a case body and a cover part are laterally connected and provided on the both sides of a back wall part disposed in the center thereof in a developed plane through the hinge for opening and closing respectively having a schematic V shape in cross section. A mold is characterized in that an injection gate, which fills a resin material, is respectively provided one place to each on the place corresponding to the case body and the cover part. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a storage case that can be cycled up.

[0002]

2. Description of the Related Art Conventionally, as a method of molding a storage case 31, a case main body is provided with two opening / closing hinges 33 each having a substantially V-shaped cross section on the left and right sides of a back wall portion 32 arranged in the center in a developed plane. In the case of a structure in which 34 and the lid portion 35 (including the case where both are lid bodies) are provided in a row on the left and right, FIG.
As shown in (a) and (b), one or two injection gates for filling the resin material are arranged at a position corresponding to the center of the back wall. G in the figure is a gate mark shown to show the position of the injection gate. In this case, since the injection gate is arranged at a location corresponding to the center of the back wall portion 32, a location where a pair of left and right hinges 33 for opening and closing are formed to be thin (for example, a thickness of 0.3 mm and a width of 0.5 mm). Since it is necessary to fill the resin in the formation portion of the case main body 34 and the lid portion 35 beyond the above, and the filling pressure cannot be increased to create the opening / closing hinge 33, there is a problem that molding takes time. .

Similarly, in FIG. 8A, in the case of the storage case 31 provided with the band 37 via the auxiliary bending hinge 36 having a substantially V-shaped cross section, a portion corresponding to the center of the back wall portion 32. While the injection gate (gate mark G1) is provided in and the injection gate (gate mark G2) is also provided in the portion corresponding to the band 35, in this case as well, it takes time to form as in the above case.

Further, as shown in FIG. 8B, in the case of a storage case 31 having no band, an injection gate (gate mark G1) is provided at a location corresponding to the center of the back wall portion 32 and the case body is provided. An injection gate (gate mark G
A configuration in which 2) is provided is also known.

Also in this case, the lid 35 or the case body 34 on the side where the injection gate is not provided is filled with the resin by the injection gate (gate mark G1) provided at a portion corresponding to the back wall 33. , The same hinge 3 for opening and closing as above
There is a problem in that it takes a long time to mold because it is molded through the forming point of No. 3.

Further, as shown in FIG. 9, a case body 3
In the case of the storage case 31 in which the lid portion 35 is continuously provided to one end of 4'through one opening / closing hinge 33 having a substantially V-shaped cross section, either the case body 34 or the lid portion 35. The injection gate (gate mark G) is arranged at a position corresponding to one predetermined position. Therefore, also in this case, the opening / closing hinge 3
Since the other lid portion or the case body is molded via the forming point of 3, there is a problem that the molding takes time.

[0007]

SUMMARY OF THE INVENTION The present invention was created as a result of intensive research in view of the above circumstances. In addition, the present invention relates to a method of forming a storage case that can be cycled up.

[0008]

In order to solve the above-mentioned problems, the present invention provides an opening / closing device having a substantially V-shaped cross-section on the left and right sides of the back wall portion arranged in the center in the development plane. A method of molding a storage case in which a case main body and a lid part are connected to each other via a hinge for left and right, in which a molding die fills a portion corresponding to the case main body and the lid part with a resin material, respectively. We have taken technical measures to provide one gate at a place. Further, according to the invention of claim 2, there is provided a method of molding a storage case, wherein a lid is continuously provided on one end of the case body through an opening / closing hinge having a substantially V-shaped cross section, and the molding die comprises: A technical measure is taken such that each of the case body and the lid portion is provided with one injection gate for filling the resin material. Further, in the invention of claim 3, the one injection gate is arranged at a position corresponding to a position biased from the center of the case body or the lid body to the side separated from the opening / closing hinge. I am taking it.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a method of molding a storage case according to the present invention will be described below with reference to the drawings. Figure 1 (a)
2, the storage case 1 is molded of polypropylene or other thermoplastic synthetic resin, and has substantially V-groove-shaped opening / closing hinges 3 at the left and right ends of the back wall portion 2 having a narrow width in the development plane.
A case body 4 and a lid body 5 are formed in series with the intermediate body 3 interposed therebetween.

Here, the case body 4 and the lid 5 may have different shapes, or may have substantially the same shape so that they can be engaged with each other. In the case of the illustrated example, the case body 4 is
It has a main body bottom plate 6 having a wide surface, and a main body peripheral wall portion 7 having a U-shape in a plan view that stands up along three sides of the main body bottom plate 6 excluding the side facing the opening / closing hinge 3.

The lid 5 is provided with a lid bottom plate 8 and upright along the four sides of the lid bottom plate 8, and is set to a size that can be fitted into the main body peripheral wall portion 7 of the case body 4. It has a lid peripheral wall portion 9 having a rectangular shape and a low height. Although not shown, the case body 4 and the lid body 5 are provided with a pair of engageable and disengageable portions, respectively.

Next, the opening / closing hinge 3 has a substantially V-shaped groove (approximately U) with respect to the wall thickness of the plate surface which constitutes the entire storage case.
The thin linear part (including the groove) is bendable. The opening / closing hinge 3 has a known thickness of 0.3 mm and a groove width of 0.5 mm, and has a shape traversing the storage case left and right (see FIG. 1B).

FIG. 2 is a vertical sectional view of the molding die 10 used in this embodiment. In the molding die 10, a molding space portion 20 for forming the storage case 1 is formed on the opposing surfaces of the male and female dies 10A and 10B. Here, the molding space portion 20
Is an internal space of the molding die 10 filled with the resin material for forming the storage case 1, and the hinge bottleneck 11 is used for forming the opening / closing hinge 3 of the storage case 1.
It is the narrow part of the filament formed in the molding space 20 of 0.

As shown in the figure, the molding space 20 is formed with a pair of hinge bottles 11, 11 corresponding to the pair of opening / closing hinges 3 of the storage case 1. A first space portion 21 in which the case body 4 is formed, a second space portion 22 in which the lid 5 is formed, and a back wall portion 2 that is sandwiched between a pair of hinge narrow passages 11
It is composed of a space portion 23.

In the female mold 10A, injection gates 13a and 13b are formed at intermediate positions of the first space portion 21 and the second space portion 22 outside the hinge bottleneck, respectively. A degassing gate 15 is formed at a position corresponding to an end of the case body 4 or the lid 5 in the figure.

A known material injection pipe (not shown) is connected to the injection gates 13a and 13b of the molding die 10 having the above-described structure to inject the resin material into the molding space 20. In the case of the illustrated example, the positions of the injection gates 13a and 13b are arranged substantially at the centers of the first and second spaces 21 and 22 forming the case body 4 and the lid 5.

As a result, even if the hinge bottleneck 11, 11 is set, the first space 2 forming the case body 4 is formed.
1 is filled with resin from the injection gates 13a and 13b arranged in the middle of the second space 22 that forms the lid 5, so that the hinge bottleneck 11 that reduces the filling speed is distant from the injection gates 13a and 13b. It can be filled efficiently in time.

In this case, the injection gates 13a, 13
The resin filled from b is the first that forms the case body 4.
The space 21 side and the second space 22 side forming the lid 5 are filled substantially evenly, and the resin material of both sides is the third space beyond the hinge bottleneck 11 forming the opening / closing hinge 3. Part 23
Abut each other near the center of.

In this way, compared with the conventional case where the injection gate is provided at the center of the third space 23 which becomes the back wall 2, the filling speed is increased to improve the cycle and the vicinity of the opening / closing hinge 3. No weld line is generated, and the strength of the opening / closing hinge 3 is not impaired. In addition,
In FIG. 1A, G1 is a gate trace showing the position of the injection gate 13a, and G2 is a gate trace showing the position of the injection gate 13b.

Next, the storage case 1 shown in FIGS. 3 and 4.
In the molding die 10, the position of the injection gate 13a is outside the center position of either the case body 4 or the lid body 5, that is, the first space portion 21 forming the case body 4 in the illustrated example, that is, the hinge bottleneck path 11. It is placed so as to be biased away from. The position of the other injection gate 13b is arranged at the center of the second space portion 22.

As a result, the resin filled from the injection gates 13a and 13b is evenly filled on the side of the first space 21 forming the case body 4 and on the side of the second space 22 forming the lid 5. If not performed, the resin material on the second space 22 side flows into the case body 4 side and both resin materials collide with each other, so that a weld line is generated on the case body 4 side except the position of the opening / closing hinge 3.

Also in this case, since the distance to the hinge bottleneck 11 serving as the opening / closing hinge 3 is longer than in the case where the injection gate is provided in the center of the conventional third space portion 23, the filling speed is accelerated and the cycle is increased. It can be realized, and no weld line is formed near the opening / closing hinge 3.

In the above embodiment, the case 1 having the two opening / closing hinges 3 on both sides of the back wall 2 is shown.
As shown in FIG. 5, a case body 4 ′ integrally formed with a back wall 2 and a storage case 1 in which a lid 5 ′ is continuously provided to the case body 4 ′ through one opening / closing hinge 3. In the case of ', the same as in the above embodiment.

In this case, as shown in the mold 10 of FIG. 6, the injection gates 13a, 1a are provided in the first space 21 'forming the case body 4'and the second space 22' forming the lid 5.
The injection gate 1 is provided so as to improve the cycle by providing the respective 3b and prevent the weld line from being formed in the hinge bottleneck 11 forming the opening / closing hinge 3.
The positions of 3a and 13b are substantially the same as in the above embodiment,
Alternatively, one of them is set in a direction away from the opening / closing hinge 3. The other structure is similar to that of the first embodiment, and the description thereof is omitted.

In the above embodiment, the storage case is for storing tape-shaped objects such as magnetic tapes, disk-shaped objects such as FDs, MDs, MOs, and plate-shaped objects as the objects to be stored. It may be. The other structure of the storage case may be a combination of known structures as appropriate. In addition, it goes without saying that various design changes can be made without departing from the spirit of the present invention.

[0026]

Since the storage case of the present invention is constructed as described above, it is possible to achieve a cycle increase of about twice that of the conventional case, which is suitable for industrial mass production. In addition, it is possible to maintain the strength of the opening / closing hinge without generating a weld line in the vicinity of the opening / closing hinge while improving the cycle, which is extremely useful.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a first embodiment of a storage case having two hinges.

FIG. 2 is a cross-sectional view showing a molding die for the storage case of the two hinges of FIG.

FIG. 3 is an exploded perspective view of a second embodiment of a storage case having two hinges.

FIG. 4 is a cross-sectional view showing a mold of the storage case of FIG.

FIG. 5 is an exploded perspective view of the third embodiment of the single-hinge storage case.

FIG. 6 is a vertical cross-sectional view of a mold of the storage case of FIG.

FIG. 7 is a perspective view of a conventional storage case showing a position of an injection gate by a gate mark.

FIG. 8 (a) is a perspective view of a storage case with a band when unfolded, and FIG. 8 (b) shows a storage case with two hinges without a band.
It is a perspective view which shows the well-known example which has arrange | positioned the spot injection gate.

FIG. 9 is a perspective view showing a gate mark in a single-hinge storage case.

[Explanation of symbols]

1 storage case 2 back wall 3 Hinge for opening and closing 4 case body 5 Lid 6 Body bottom plate 7 Body wall 8 lid bottom plate 9 Peripheral wall 10 Mold 10A, 10B Male and female type 11 Hinge bottleneck 13a, 13b injection gate 15 Degassing gate 20 Molding space 21 First Space Section 22 Second space section 23 Third Space Section

Claims (3)

[Claims] 1. A storage case in which a case main body and a lid are connected to each other on the left and right sides of a back wall portion arranged in the center on an unfolded plane via opening and closing hinges each having a substantially V-shaped cross section. A method of molding a storage case, characterized in that the molding die is provided with one injection gate for filling a resin material at each position corresponding to the case body and the lid. 2. A method of molding a storage case, wherein a lid is connected to one end of a case main body through an opening / closing hinge having a substantially V-shaped cross section, wherein a molding die is the case main body. A method of molding a storage case, characterized in that the lid is provided with one injection gate for filling each with a resin material. 3. The one injection gate is arranged at a position corresponding to a position deviated from the center of the case main body or the lid toward the side separated from the opening / closing hinge. The method of forming the storage case described in.