JPH04311449A - Foamed synthetic resin small box and manufacture thereof - Google Patents

Abstract

PURPOSE:To enable an integral formation of a box body and a lid body by a method wherein side plates of the box body are planted on a periphery of a bottom side through a cut-in hinge part, and a lid plate is connected in a state that one side of the lid plate is opened in the horizontal direction on an upper side of the side plates of the box body through the cut-in hinge part. CONSTITUTION:A side plate 13 of a foamed synthetic resious box body 11 is planted on a periphery of a bottom plate through a cut-in hinge part 14, and a lid plate 12 is connected in a state that one side of the lid plate 12 is opened in the horizontal direction on an upper side of the side plate 13 through another cut-in hinge part 16. In the cut-in hinge part 14 of the box body 11, a cut 17 having a prescribed depth is formed on an extension of an inner surface of the side plate 13 inside the bottom plate 15, while in the cut-in hinge part 16 of the lid plate 12, a cut 18 having a prescribed depth is formed on an extension of an outer surface of the side plate 13 inside the lid plate 12. Thus, as the box body 11 and the lid plate 12 can be molded integrally, only one metal die will do, whereby working effiency is improved and the cost is reduced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foamed synthetic resin assembly box that can be developed into a flat plate shape and a method for manufacturing the same.

0002

2. Description of the Related Art Conventionally, as shown in FIG.
A device equipped with
No. 46). The box body 1 has a side plate 3 erected around a bottom plate 5 via a cut hinge part 4, and a cut hinge part 4 has a cut 6 of a predetermined depth inside the bottom plate 5 on an extension of the inner surface of the side plate 3. It is formed into. The cut hinge portion 4 allows the side plate 3 to be unfolded into a flat plate as shown in FIG. 11, making it convenient to store and transport the box body 1 in an empty state. In the assembly box having the above structure, the box body 1 is molded into a three-dimensional shape using a mold, and the lid plate 2 is molded using a separate mold.

0003

[Problem to be Solved by the Invention] However, in the conventional assembly box described above, since the box body 1 and the lid plate 2 are molded separately, two sets of molds are required, which not only complicates the manufacturing process but also ,
Naturally, there was the problem of increased costs. In addition, in terms of maintenance, it was necessary to perform maintenance on two sets of molds, and furthermore, in terms of product management, it was necessary to perform maintenance on both the box body and the lid plate, which was extremely troublesome. The present invention was made in view of such conventional problems, and an object of the present invention is to provide an assembly box in which a box body and a lid plate can be integrally molded, and a method for manufacturing the same.

0004

[Means for Solving the Problems] In order to achieve the above object, the foamed synthetic resin assembly box of the present invention is provided with at least one lid plate on the box body, and the side plate of the box body has a cut hinge portion. one side of the lid plate is connected to the upper side of the side plate of the box body in a horizontally open state through a notched hinge part, and the notched hinge part of the box body has a predetermined depth. The notch is formed on the inner surface extension of the side plate inside the bottom plate, and the cut hinge portion of the lid plate has a notch of a predetermined depth formed on the inner surface extension of the side plate inside the lid plate.

[0005] It is preferable that the notch hinge portion of the box body is provided with a notch hinge reinforcing portion on the opposite side of the bottom plate from the notch. The method for manufacturing an assembly box having the above configuration includes providing a mold cavity for integrally molding the assembly box having a concave cross-sectional shape in the mold, the mold cavity having a side plate molding part around the bottom plate molding part,
At least one lid plate molding part is connected to the edge of the side plate molding part, and a notch forming plate is provided on the inner surface of the side plate molding part so as to protrude by a predetermined depth into the bottom plate molding part, and the outer surface of the side plate molding part A notch forming plate is provided so as to protrude by a predetermined depth into the lid plate molding section, and foamable resin beads are filled into the mold cavity and heated and molded.

[0006] Furthermore, the method for manufacturing an assembly box in which the notched hinge reinforcing portion is formed includes forming a recessed portion for forming the notched hinge reinforcing portion of the box body on the opposite side of the notch forming plate in the bottom plate molding portion of the mold cavity. The mold cavity is filled with foamed resin beads, heated to temporarily fuse them, and after cooling, the mold is opened at minute intervals, and the recesses are cut and foamed resin beads for the hinge reinforcement are filled and the mold is closed. , which is heated to perform the final fusion.

[0007]

[Function] The assembly box with the above structure is connected to the box body with the side plates standing up around the bottom plate, with one side of the lid plate open horizontally to the top side of the side plate of the box body. By providing a mold cavity with a concave cross-sectional shape in the box body, the box body and the lid plate can be integrally molded. When the notch hinge reinforcement portion is formed, the notch hinge portion of the box body is strengthened, and the durability of the box as assembled is improved, and heavy objects can be accommodated.

[0008]

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 6, but it goes without saying that these do not limit the present invention in any way. As shown in FIG. 1, the assembly box of this embodiment is made of foamed synthetic resin and includes a box body 11 and a pair of left and right lid plates 12. As the foamed synthetic resin, polystyrene resins, polyolefin resins such as polyethylene and polypropylene, polyurethane resins, etc. are suitably used. The box body 11 includes a side plate 13 erected around a bottom plate 15 via a notch hinge part 14, and a lid plate 12.
As shown in the figure, it has a double door shape, and one side is connected to the upper side of the side plate 13 via a notch hinge part 16 in a horizontally open state. Furthermore, the cut hinge part 14 has a cut 17 of a predetermined depth formed inside the bottom plate 15 on the inner surface extension of the side plate 13, and the cut hinge part 16 has a cut 18 of a predetermined depth formed inside the cover plate 12. It is formed on an extension of the outer surface of the side plate 13. The thickness of these notch hinge parts 14 and 16 is set taking into account the size of the assembly box, the type of resin, the expansion ratio, the presence or absence of a skin layer, etc., but it is usually 0.5 mm.
It is preferable that the thickness be approximately several mm.

In order to manufacture the assembly box having the above structure, first, as shown in FIG. 2, a mold cavity 22 in which the assembly box can be integrally molded is provided in a mold 21. The mold 21 consists of a pair of core molds 23 and a cavity mold 24, the cavity mold 24 is equipped with a plurality of resin bead fillers 25, and the wall forming the mold cavity 22 has a large number of steam holes 26. is open. mold cavity 2
2 has a concave cross-sectional shape, has a side plate molded part 28 around a bottom plate molded part 27, and a pair of cover plate molded parts 29 are connected to opposite sides of the side plate molded part 28. And side plate molding part 2
A notch forming plate 30 is provided on the inner surface of the bottom plate molding part 27 so as to protrude by the depth of the notch 17, and a notch forming plate 31 is provided on the outer surface of the side plate molding part 28 so as to protrude into the bottom plate molding part 29 by the depth of the notch 18. Provided so that it protrudes by the depth. These cut-forming plates 30 and 31 form cuts 17 and 18, and the adjacent side plates 13
It is made from metal, gunmetal, etc. Next, foamable resin beads 32 are filled into the mold cavity 22 from the filling device 25, steam is supplied into the mold cavity 22 from the steam hole 26, and the molded product is heated and molded, and then cooled and the molded product is taken out. In this way, an assembly box having the shape shown in FIG. 1 can be integrally molded.

As shown in FIG. 3, the assembled boxes obtained as described above can be unfolded into a flat shape via the cut hinge parts 14 and 16, so that a plurality of boxes can be stacked and stored or transported. Therefore, large storage space is not required,
It also has good transportation efficiency. In addition, the adjacent side plates 13
If the joints of the lid plates 12 are made into a so-called joint structure as illustrated in FIGS. 4 to 6, or the joints between the lid plates 12 are made into a joint structure as illustrated in FIG. 1, the tightening action of the joint structure The strength of the assembled box is improved.

As another embodiment of the present invention, as shown in FIG. 7, a notched hinge reinforcing portion (hereinafter referred to as reinforcing portion) 19 may be formed on the surface of the bottom plate 15 opposite to the notch 17. The necessity of the reinforcing part 19 is determined by the type of resin used for the assembly box, the weight of the contents, etc., but generally,
In the case of polyolefin resin, the reinforcing part 19 is often not required because it has excellent bending strength, and in the case of polystyrene resin, it is often preferable to provide the reinforcing part 19. Also, the material of the reinforcing part 19 A material of the same quality as the material of the assembly box, an olefin-styrene copolymer resin, etc. are suitable as the material.

In order to manufacture an assembly box provided with the reinforcing portion 19, as shown in FIG. A recess 33 is provided for use. And the filling device 25
The mold cavities 22 are filled with foamable resin beads 32, and steam is supplied from the steam holes 26 into the mold cavities 22 to heat and temporarily fuse them. Temporary welding is the process by which the foamed resin beads 32 are bonded to the extent that the temporarily welded material does not collapse when the mold is opened, and so that water vapor can penetrate into the inside during the actual welding of the reinforcing part 19 (described later). A state in which a gap exists between The conditions for temporary welding are determined by the type of resin, the thickness of the molded body, etc.
One-sided heating under low pressure to normal pressure of kg/cm2 to 0.4 kg/cm2 is preferred. Next, after cooling slightly if necessary, the mold is opened by a minute gap (corresponding to the thickness of the reinforcing part 19), and foamed resin beads 34 for the reinforcing part are inserted into the recess 33 from a filler (not shown) provided in the recess 33. After filling, the mold is closed and final fusion bonding is performed to integrate the reinforcing portion 19 with the bottom plate 15. In this way, an assembly box having the shape shown in FIG. 7 can be integrally molded. Note that during the above temporary welding, a small amount of the foamed resin beads 32 also enters the recess 33 and is temporarily fused, and after that, a minute gap is opened and the foamed resin beads 34 for the reinforcing portion are filled. However, since the main fusion is carried out, the reinforcing part 19 and the bottom plate 15 in the vicinity thereof are subjected to a type of compression molding, thereby increasing flexibility and providing properties suitable for the notched hinge part 14.

[0013] Furthermore, the reinforcing portion 19 can be further reinforced. For example, a box for heavy objects can be made by attaching a film or the like to the cut hinge portion 14 corresponding to the reinforcing portion 19 and performing integral molding. The film (or sheet) used in this case is preferably the same or similar to the material used for molding the box because it has good fusion properties during molding. For example, if the box material is polystyrene,
It is better to use a film made of high-impact polystyrene. However, it goes without saying that different types of materials can be used as long as they can be bonded. In addition, although the above description has been made regarding a double-folding lid plate, it goes without saying that the present invention can also be applied to a single-opening lid plate.

[0014]

Effects of the Invention As explained above, the present invention has a box main body in which the side plate is erected around the bottom side through a notch hinge part, and one side of the lid plate is a side plate of the box main body through a notch hinge part. Since the box body and the lid plate are connected to each other in a horizontally open state on the upper side, the box body and the lid plate can be integrally molded. Therefore, only one set of molds is required, greatly improving work efficiency and reducing costs. Furthermore, only one set of molds is required.
Furthermore, since the product is integrally molded, mold maintenance and product inventory management are easy. Further, since the assembled box can be unfolded into a flat shape via the cut hinge portion, storage space can be reduced by stacking a plurality of boxes and storing or transporting them, and transportation efficiency is also good. Furthermore, by forming a notched hinge reinforcing portion on the bottom plate, the notched hinge portion of the box body is strengthened, improving the durability of the assembled box and making it possible to accommodate heavy objects.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an assembly box showing an embodiment of the present invention.

FIG. 2 is a sectional view of the assembly box manufacturing apparatus shown in FIG. 1;

FIG. 3 is a developed view of the assembly box shown in FIG. 1;

FIG. 4 is a sectional view showing an example of a joint structure of side plates in an assembly box.

FIG. 5 is a sectional view showing an example of a joint structure of side plates in an assembly box.

FIG. 6 is a sectional view showing an example of a joint structure of side plates in an assembly box.

FIG. 7 is a sectional view of an assembly box showing another embodiment of the present invention.

8 is a sectional view of the assembly box manufacturing apparatus shown in FIG. 7. FIG.

9 is a developed view of the assembly box shown in FIG. 7. FIG.

FIG. 10 is a sectional view showing an example of a conventional assembly box.

11 is a developed view of the conventional assembly box (box main body) shown in FIG. 10. FIG.

[Explanation of symbols]

11 Box body
12 Lid plate 13 Side plate
14 Cut hinge part (box body side) 15 Bottom plate
16 Notch hinge part (lid plate side) 17 Notch (box body side) 18 Notch (lid plate side) 19 Notch hinge reinforcement part 21 Mold 22 Mold cavity
27 Bottom plate molding part 28 Side plate molding part
29 Lid plate forming part 30 Notch forming plate (box body side) 31 Notch forming plate (
Lid plate side) 32 Foaming resin beads 3
3 Recessed portion 34 Foamed resin beads for reinforcing portion

Claims (4)

[Claims] Claim 1: A box body is provided with at least one lid plate, a side plate of the box body is erected around the bottom plate through a notch hinge part, and one side of the lid plate is provided with a side plate of the box body through a notch hinge part. It is connected to the top of the side plate in a horizontally open state,
The notch hinge portion of the box body has a notch of a predetermined depth formed on the inner surface extension of the side plate inside the bottom plate, and the notch hinge portion of the lid plate has a notch of a predetermined depth formed on the outer surface extension of the side plate inside the lid plate. An assembly box made of foamed synthetic resin. 2. The foamed synthetic resin assembly box according to claim 1, further comprising a notched hinge reinforcing portion formed on the surface of the bottom plate opposite to the notch. 3. A mold cavity for integrally molding an assembly box having a concave cross-sectional shape is provided in the mold, the mold cavity has a side plate molding part around the bottom plate molding part, and at least one molding part is provided on the edge of the side plate molding part. A notch forming plate is provided on the inner surface of the side plate forming part so as to protrude by a predetermined depth into the bottom plate forming part, and a notch forming plate is provided on the outer surface of the side plate forming part inside the cover plate forming part. 1. A method for producing an assembly box made of foamed synthetic resin, characterized in that the mold cavity is provided so as to protrude by a predetermined depth, and foamed resin beads are filled into the mold cavity and then heated and molded. 4. A recess for forming the notch hinge reinforcement portion of the box body is provided on the opposite side of the notch forming plate in the bottom plate molding portion of the mold cavity, and foamed resin beads are filled in the mold cavity and heated to temporarily fuse. 3. The manufacturing method according to claim 2, wherein after cooling, the mold is opened at minute intervals, the recess is filled with foamed resin beads for the cut hinge reinforcing portion, the mold is closed, and the mold is heated for final fusion.