JP3357696B2 - Method for manufacturing inner box of insulated box - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an inner box of a heat insulating box such as a freezer and a refrigerator.

[0002]

2. Description of the Related Art Insulated boxes, such as conventional freezers and refrigerators, are:
It is formed by interposing a heat insulating material between the outer box and the inner box. As a method of manufacturing the inner box of the heat insulating box, a resin sheet is set in a mold, and thereafter, the inside of the mold is evacuated and the sheet is brought into close contact with the mold to form an inner box. (Hereinafter referred to as the VF method) or an injection molding method for producing an inner box by injecting a molten resin into a gap formed between dies by an injection molding machine and forcibly filling the gap with the resin. Or after injecting molten resin into the mold,
There is an injection press method (hereinafter referred to as an imprint method) in which a product is compressed and formed by applying a pressing pressure to the resin.

[0003]

However, of the conventional methods for manufacturing an inner box of a heat-insulating box, the injection molding method and the imprinting method form a deeper one such as an inner box of a refrigerator. Therefore, there is a problem that the size of the mold is increased, and accordingly, the manufacturing cost of the mold is increased, and the manufacturing cost of the inner box is increased.

For this reason, the VF method is generally used. However, in this VF method, an expensive resin such as polystyrene must be used as a resin to be used as a material, resulting in a high material cost and a high manufacturing cost. There was a problem of becoming.

Further, in the VF method, since a mold used is formed by bonding an aluminum casting, there is a variation in accuracy of the mold itself. Since the degree of adhesion of the resin to the mold slightly differs depending on the molding time and the like, there is a problem that the accuracy of the inner box varies.

Further, in the VF method, since the inner box is formed as a completed one, there is a problem that a large space is required for storing the finished product. In order to solve this problem of storage space, there is a case where the inner box is stored in a disassembled form into a flat plate, and the inner box is assembled when desired. Problems arise.

An object of the present invention is to provide a method for manufacturing an inner box of an insulated box, which is capable of manufacturing an inner box which can be stored at a low cost without requiring a large storage space. .

[0008]

SUMMARY OF THE INVENTION The present invention relates to a method for manufacturing an inner box of an insulated box formed by interposing a heat insulating material between an outer box and an inner box formed of resin. This is a method for manufacturing an inner box in which a flat plate having an expanded shape is formed, and a fold for forming the inner box on the flat plate is formed at the time of forming, so that a box body can be formed from the flat plate when desired.

[0009]

With this configuration, it is possible to form the inner box when desired by forming a flat plate having the developed shape of the inner box, and further forming a fold at the time of forming the flat plate.

[0010]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an inner box forming apparatus for forming an inner box by a method of manufacturing an inner box of a heat insulating box according to one embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a fixed die having a concave portion 2 formed on one side, and 3 denotes a hydraulic press driven by a drive unit (not shown) to enter and exit the concave portion 2 of the fixed die 1. It is.

Here, the hydraulic press 3 moves the resin 4 poured into the concave portion 2 of the fixed mold 1 from the injector 8 described later while pressing the resin 4 against the back wall of the concave portion 2 to move the resin 4 into the fixed press 1 and the hydraulic press. 3, a closed gap having a predetermined width (hereinafter referred to as a forming gap) for forming a flat plate 5 having an expanded shape of an inner box having an opening as shown in FIG. .

In FIG. 1, guide grooves 6 are formed on the upper and lower edges of the concave portion 2 of the fixed mold 1, respectively. A stopper 7 is slidably held in the guide grooves 6 in the lateral direction. I have. Here, the stopper 7 is used for the hydraulic press 3
Slides into the guide groove 6 while abutting on the hydraulic press 3 when entering the fixed mold 1, and eventually stops at the flat plate forming position by abutting against the inner wall of the guide groove 6. Then, the molding gap is sealed.

On the other hand, reference numeral 8 denotes an injector attached to the fixed mold 1. The injector 8 injects the molten resin 4 so that the resin 4 faces the concave portion 2 located at a position further away from the injector 8. Resin injection port 1 formed
a to gradually flow into the concave portion 2 from a. Note that the amount of the resin 4 injected by the injector 8 at one time is an amount necessary to form one flat plate 5, and the resin 4 is heated at the time of molding as in the conventional VF method. Since there is no need, a cheap one may be used.

Here, the injection of the resin 4 from the injector 8 is performed in response to a molding command from a control device (not shown), and the hydraulic press 3 also enters the fixed mold 1 in accordance with the molding command. This hydraulic press 3 allows the resin injection port 1
The resin 4 gradually flowing into the recess 2 from a is pressed against the back wall of the recess 2.

At this time, since the resin 4 is poured into the concave portion 2 from the resin injection port 1a when the concave portion 2 is not in the closed state, the tightening pressure applied to the hydraulic press 3 and the fixed mold 1 is supplied in a closed state. Is not so large as compared with the case where the injection pressure of the resin by the conventional injection molding method is 1/2.
The size is about １ ／. For this reason, the hydraulic press 3
The fixed mold 1 is made of a relatively soft material such as aluminum which is easy to process.

Further, since the inner box as a finished product is not formed, but the flat plate 5 having the developed shape of the inner box is only formed, the depth dimensions of the hydraulic press 3 and the fixed mold 1 can be reduced, and the hydraulic pressure can be reduced. The press 3 and the fixed mold 1 can be reduced in size.

When the hydraulic press 3 further enters the recess 2, the resin 4 is pressed by the hydraulic press 3.
When the hydraulic press 3 reaches the flat plate forming position and forms a forming gap as shown in FIG. 4 described later, the inner box is closed. A flat plate 5 having an open shape is formed.

Immediately after the flat plate 5 is formed in this way, the hydraulic press 3 is retracted from the concave portion 2 and the flat plate 5 is once bent by, for example, a fold forming means (not shown), thereby obtaining a structure as shown in FIG. The crease 9 is formed.

Here, the flat plate 5 immediately after being formed in this way
When the fold 9 is formed, a hinge effect is generated, and if the flat plate 5 is bent along the fold 9 when desired, the inner box can be formed in a short time. When the inner box is formed, the joining portion of the inner box is fixed by fixing a tape at a predetermined portion of the flat plate 5 with a tape or by fitting the fixed portion by forming a fitting portion at a predetermined portion of the flat plate 5. And so on.

Next, the manufacture of the inner box by the inner box manufacturing method thus configured will be described. First, when a molding command is issued from the control device, as shown by an arrow A in FIG. 3, the resin 4 melted by the injector 8 is gradually poured into the recess 2 from the resin injection port 1a, and the hydraulic press 3 is moved by an arrow B as shown by an arrow B in FIG. Of the concave portion 2 and the resin 4 starts to be pressed against the back wall of the concave portion 2.

In this state, since the inside of the concave portion 2 is not hermetically sealed, the hydraulic press 3 and the fixed mold 1 do not need to receive much pressure of the resin 8 injected from the injector 10.

The hydraulic press 3 is provided with a stopper 7
While sliding into the guide groove 6, the resin 4 further enters the concave portion 2, and accordingly, the resin 4 is sandwiched between the hydraulic press 3 and the back surface of the concave portion 2 and gradually spreads vertically as shown in FIG. .

Eventually, as shown in FIG. 4, the stopper 7 comes into contact with the inner wall of the guide groove 6, and the hydraulic press 3 stops at the flat plate forming position. At this time, the single flat plate 5 injected from the injector 8 is formed. The required amount of resin permeates into the molding gap to form the flat plate 5.

Immediately after the inner box is formed in this manner, the hydraulic press 3 is moved into the recess 2 as shown by the arrow in FIG.
The flat plate 5 is creased by the crease forming means to prepare for the next molding command. The projection 5a extending rearward from the rear surface of the flat plate 5 is
Remove and remove.

The flat plate 5 thus creased 9 is stored in a warehouse or the like until the heat-insulating box is manufactured. When the flat plate 5 is manufactured, the flat plate 5 is transported out of the warehouse or the like, and then bent along the crease 9. As shown in FIG. 6, the joining portion is stopped by a tape 11 to form an inner box 10 having an opening 10a.

As described above, the inner box 10 is not formed as a finished product, but is formed as a flat plate 5 using an inexpensive resin, so that the hydraulic press 3 and the fixed mold 1 are reduced in size and the manufacturing cost is reduced. Can be. In addition, since it is formed into a flat plate, the time for formation can be reduced and the space for storage can be narrowed.

In this manufacturing method, man-hours for forming the inner box are required. However, even if such man-hours are applied, the manufacturing cost of the hydraulic press 3 and the like is reduced, and the time for forming is reduced. Also, significant advantages such as a reduction in storage space can be obtained.

In the above description, the case where the fold forming means is used for forming the fold 9 on the flat plate 5 has been described. However, the present invention is not limited to this, and the fold 9 for forming the fold 9 on the hydraulic press 3 is not limited thereto. The fold 9 may be formed when the projection is provided and the flat plate 5 is press-formed.

[0031]

As described above, according to the present invention, since the flat plate is formed in the developed shape of the inner box, the fixed mold and the like can be reduced in size, thereby reducing the manufacturing cost of the fixed mold and the like. And the cost of the inner box can be reduced.

Further, since the inner box is formed into a flat plate, a large storage space is not required, and the fold is formed at the time of forming the flat plate, so that the inner box can be formed when desired without forming the inner box as a finished product. It can be formed in a short time.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an inner box forming apparatus for forming an inner box by a method of manufacturing an inner box of a heat insulating box according to one embodiment of the present invention.

FIG. 2 is a perspective view of a flat plate formed by the inner box forming device.

FIG. 3 is a view showing a state in which a hydraulic press of the inner box forming apparatus enters a fixed mold.

FIG. 4 is a diagram showing a state in which the hydraulic press has reached a flat plate forming position.

FIG. 5 is a diagram showing a state in which the hydraulic press has retreated from the inside of a fixed mold.

FIG. 6 is a perspective view of an inner box formed by assembling the flat plate.

[Explanation of symbols]

 3 Hydraulic press 4 Resin 5 Flat plate 9 Fold 10 Inner box

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-152830 (JP, A) JP-A-61-49818 (JP, A) JP-A-61-179712 (JP, A) 154376 (JP, U) Fully open sho 59-30893 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 33/00-33/76 B29C 45/00-45/84 F25D 23/02 F25D 23/06-23/08

Claims (1)

(57) [Claims] The present invention relates to a method for manufacturing an inner box of an insulating box formed by interposing a heat insulating material between an outer box and an inner box formed of resin.
In, forming a flat plate having the developed shape of the inner box,
At the time of forming a fold to enable inner box formation on this flat plate
Once formed, a box can be formed from this flat plate when desired.
A method for manufacturing an inner box of an insulated box body, characterized in that: