JPH08295336A - Collapsible container - Google Patents

Abstract

PURPOSE: To increase the productivity and facilitate the assembly by producing an upper side board and a lower side board and a freely bendable thinner layer joining the two all integrally by injection molding relating to a collapsible container of plastic of which two opposed side boards are bendable inward and two other opposed side boards are capable of being turned inward simultaneously with rise. CONSTITUTION: Each of upper longer side boards 2 and each of shorter side boards 5 are joined with an upper frame 1 of a container by hinges and each of lower longer side boards 3, with a bottom board 7 by hinges. A thinner layer 4 joins the adjoining upper and lower longer side boards 2, 3. This assembly is produced integrally from a material of the polypropylene series by injection molding. The thinner layer 4, which is freely bendable, and the hinge mechanism which each of the longer side boards 2, 3 has enable each longer side board 2, 3 to be bent along the thinner-layer part 4. The thinner layer 4 is provided at intervals discontinuously with a cut between adjacent layers so as to be bent smoothly. A fastening piece 72 is provided on an outer frame 71 of the bottom board 7 and by fitting small projections 73 on a stepped part 53 of a fastening piece 52 in the lower part of the shorter side board 5 a fixing is lightly effected and the shorter side board 5 is prevented from returning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a collapsible container, and more particularly to a collapsible container which is easy to assemble and fold and is easy to mold with a plastic material.

[0002]

2. Description of the Related Art Containers are used to transport various goods, parts, materials, etc., and folding containers are used to reduce the volume of an empty box after use.
This container is generally used in large quantities for industrial use.
Therefore, folding and assembling operations are easy, and durability and load resistance are required. The plastic foldable container shown in FIG. 6 is the most popular and well known in the market as one satisfying these requirements. In this container, the side plate (generally the long side) on one side of the container is bent inward at the lateral center, and the side plate (generally the short side) on the other side of the container is the upper end. It is a type (center bending type) that rotates so as to flip up inward with the part as a spindle.
Normally, the height after folding is 1/4 to 1 / the height when assembled.
Reduce to about 3.

Further, there is a conventional center folding type folding container which is made of a heat insulating material for keeping cold (Japanese Patent Laid-Open No. 63-96031, 2-11032).
etc). In this container, each member is composed of a hollow molded body, and urethane foam is filled in the hollow molded body. The upper side plate, the lower side plate and the bottom plate of the middle folding side plate are blow-molded into one body, and their joints can be bent. In blow molding, the seam portion is a thin layer formed by pressing both sides of the hollow portion inward and bringing them into contact with each other to partially fuse them.

[0004]

In the folding container described above, the long side plate is composed of two upper and lower independent molded bodies, and the two molded bodies are hinged to each other at their joints. Hinge connection is a method in which a hinge hole is provided in both joints at the joint, and this is arranged in a straight line, and a metal pin is inserted into the hinge hole, or a hinge hole is provided at the joint in one of the joints. , A hinge shaft which is one body with the molded body is provided in the molded body of the seam portion of the other molded body,
This is a method of inserting the hinge shaft into the hinge hole. In any of these methods, two long side plates must be molded for one side, and the two molding plates must be assembled by a hinge mechanism. The costs for these cannot be ignored.

In the above-mentioned blow molding, the upper plate and the lower plate are joined together by a thin layer, but various problems arise in smoothly bending at the thin layer. If the thin layer is a little thick, it will not be perfectly horizontal when folded and tends to be slightly raised. If the thin layer is too thin, problems of strength and durability will occur. In order to solve these problems, the present invention specifically improves the long side plate, and the upper long side plate and the lower long side plate are formed by injection molding.
The purpose is to bend the seam part of the body flexibly, improve the productivity of the container, and reduce the cost.

[0006]

SUMMARY OF THE INVENTION The inventor has made a folding container of a middle folding type by bending the upper and lower sides of the folding side plate and the joint portion between them into one body so that the joint portion can be bent. Moreover, they have found that it is possible to have sufficient durability and arrived at the present invention. That is, the present invention is a plastic folding container in which one opposite side plate is bent inward at the center in the lateral direction, and the other opposite side plate is turned upward inward with the upper part as a support shaft. The folding container is characterized in that the lower side plate and a bendable thin layer connecting them are integrally formed by injection molding. In this container, it is desirable that the bendable thin layer connecting the upper plate and the lower plate is provided intermittently in the lateral direction, and the gap between them is separated.

A concrete description will be given below based on an embodiment shown in the drawings. FIG. 1 is a schematic perspective view of a folding container showing an example of the present invention. An upper long side plate 2 is hinged to an upper frame 1 of the container. The short side plate 5 is also hinged to the upper frame. The lower long side plate 3 is hinged to the bottom plate 7. The upper long side plate and the lower long side plate are connected by a thin layer 4, and these are injection-molded into one body by using the same material. The thin layer 4 is bendable and the long side plate can be bent at the thin layer portion by the hinge mechanism between the thin layer 4 and the upper and lower long side plates.

FIG. 2 shows a cross section of the long side plate, and FIG. 3 shows a front view of the thin layer portion. The thin layer is thinner than the wall thickness of the side plate as shown in FIG. When the thin layer is thick, the upper and lower side plates do not completely fold and become slightly floating when folded. On the other hand, if it is too thin, problems such as strength and durability will occur. The desired thickness depends on the size of the container, but is 0.2 to 0.
It is about 5 mm. Further, in order to facilitate the bending, the thin layer portions 4 may be intermittent as shown in FIG. 3 and cut between them to form the discontinuous portion 41.

The thin layer serving as the folded portion is thin as described above, and the folding container is frequently folded and assembled, but according to the durability test, even if the folding and assembling are repeated 10,000 times. There was no problem. Polypropylene resin is the most desirable material for the long side plate because of the durability of the thin layer and the moldability of the side plate including the thin layer.

The short side plate 5 is hinge-joined to the upper frame 1, and is rotatable inward and upward with the hinge portion serving as a pivot. The fixing mechanism between the bottom plate and the lower portion of the short side plate and the engaging mechanism at the corners of the short side plate and the long side plate are basically the same as those of the conventional non-adiabatic folding container described above. For reference, a partial view of the engaging mechanism at the corners of the short side plate and the long side plate is shown in FIG. 4, and an engaging mechanism at the bottom plate and the lower part of the short side plate is shown in FIG. As shown in FIG. 4, when the container is assembled, the engagement piece 42 of the long side plate is inserted into the engagement hole 51 of the short side plate and locked.

As shown in FIG. 5, the bottom plate and the lower portion of the short side plate are provided with an engaging piece 72 partially on an outer frame 71 of the bottom plate, and a small projection 73 at the tip thereof is a step of the engaging piece 52 at the lower side of the short side plate. It is lightly fixed by being hooked on the portion 53 and prevents the short side plate from returning naturally. Further, the short side plate is prevented from coming off to the outside by the outer frame 71 of the bottom plate.

The hinges on the upper side of the short side plate, the upper side of the short side plate and the lower side are the same as the conventional ones, and the hinge shafts provided on the long side plate and the short side plate are inserted into the hinge holes provided on the upper frame and the bottom plate. It consists of a structure. In the figure, 8
Is a groove, and there are projections corresponding to the grooves at the four corners of the bottom surface of the container. When the containers are stacked, the projections enter the grooves. The protrusions on the bottom are for reinforcing the container. This structure is also conventionally known.

[0013]

EFFECTS OF THE INVENTION Since the middle side plate of the folding container is molded by injection molding, the productivity is high. Further, unlike the conventional case, it is not necessary to join the middle bent side plates to each other by hinges, and the structure is simple, which facilitates the assembly when manufacturing the container.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a folding container according to the present invention.

FIG. 2 is a cross-sectional view of a long side plate bent at a central portion.

FIG. 3 is a front view of a bent portion of a long side plate.

FIG. 4 is a partial perspective view showing an engaged state at a corner portion of a long side plate and a short side plate.

FIG. 5 is a partial cross-sectional view showing an engagement state between a bottom plate and a lower end portion of a short side plate.

FIG. 6 is a schematic perspective view of a conventional folding container.

[Explanation of symbols]

 1 Frame 2 Upper Long Side Plate 3 Lower Long Side Plate 4 Thin Layer 5 Short Side Plate 6 Corner Engagement 7 Bottom Plate 8 Recessed Groove 9 Rib 10 Hinge

Claims (3)

[Claims] 1. A plastic folding container in which one opposite side plate is bent inward at a lateral center portion and the other opposite side plate is turned inward and upward about a support shaft as an upper portion, and the opposite side plate is an upper plate of the folding side plate. A foldable container characterized in that a lower plate and a bendable thin layer connecting them are integrally formed by injection molding. 2. The folding container according to claim 1, wherein the bendable thin layer is provided intermittently. 3. The folding container according to claim 1, wherein the folding side plate is formed of a polypropylene material.