JPH09119771A - Manufacture of heat insulation case and heat insulating structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of components and the assembling steps and to enhance the heat insulation performance. SOLUTION: The method for manufacturing a heat insulation case comprises the steps of molding a case 15 by using molds 11, 12 by blow molding synthetic resin, charging the hollow part 16 of the case 15 with open cell foam urethane 17 in the state supported to the molds 11, 12, and evacuating in vacuum the box 15. Thus, after the charging, the urethane 17 becomes a desired shape, and is not necessary to be processed later and further since the case 15 is supported to the molds 11, 12 at the time of charging the urethane 17, it is not deformed by the charging pressure. Therefore, the heat insulation case can be easily and accurately formed in a complicated shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat insulating box and a method of manufacturing a heat insulating structure for improving heat insulating performance between the inside and outside of a refrigerator or a freezer.

[0002]

2. Description of the Related Art Generally, in a refrigerator or a freezer, for example, heat insulation between the inside and the outside of the refrigerator is an important factor for improving the refrigerating capacity and the freezing capacity. For this reason, in recent years, as shown in FIG. 7, a heat insulating box 1 that constitutes an outer frame of a refrigerator or the like.
In addition, the vacuum insulation pack 2 is used.

This vacuum insulation pack 2 is arranged in a space between an outer box 3 made of an iron plate and an inner box 4 made of synthetic resin of the heat insulation box 1, and one surface thereof is in close contact with the inner surface 3a of the outer box 3. Pasted in. Then, the independent foam insulation material 5 such as polyurethane foam is injected into the space between the outer box 3 and the inner box 4, and the outer box 3
A heat insulating layer is formed between the inner box 4 and the inner box 4.

[0004]

However, in the vacuum heat insulating pack 2, after the spacer material made of an inorganic powder having a low thermal conductivity is filled in a middle bag such as kraft paper having good air permeability, A spacer material is vacuum-sealed together with a bag with an outer packaging material having a good vacuum holding property.

Therefore, in order to manufacture this vacuum insulation pack 2, each component of the spacer material, the inner bag and the outer packaging material is required, and further, the spacer material is heated and dried, and the spacer material is filled in the inner bag. The processing and assembly process of inner bag, insertion of getter agent, and vacuum exhaust is required.

Further, a step of attaching the vacuum heat insulating pack 2 to the inner surface 3a of the outer box 3 is also necessary, and the area occupied by the vacuum heat insulating pack 2 with respect to the total heat transfer area of the heat insulating box 1 is small. There was a problem of poor performance.

Therefore, an object of the present invention is to provide a heat-insulating box body and a method of manufacturing a heat-insulating structure which has a small number of parts and a small number of working / assembling steps and has high heat-insulating performance.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, a case is molded by blow molding a synthetic resin using a molding die, and the case is supported by the molding die. In this state, the hollow portion of the case is filled with open-cell urethane foam, and the inside of the case is evacuated to form a vacuum.

According to a second aspect of the present invention, the heat insulating box according to the first aspect is arranged in the space between the outer box and the inner box,
The closed cell urethane foam is filled in the space between the outer box and the inner box.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments.

The heat insulating box 1 of the first embodiment shown in FIG.
As for 0, for example, as shown in FIG. 5, a synthetic resin tube is inserted into a molding portion 13 formed by an outer molding die 11 for blow molding and an inner molding die (split mold) 12,
A box 15 as a case along the molding portion 13 is blow-molded by feeding a predetermined air from the air inlet 14.

Next, as shown in FIG. 6, the molding dies 11 and 12 are used to support the box 15, and the air inlet 1 is used.
From 4 on, the open cell urethane foam 17 is filled in the hollow portion 16 of the box 15. Since the molding dies 11 and 12 are used in this manner, the open cell urethane foam 17 can be easily filled in the entire box 15. In addition, since the open-cell urethane foam 17 has a desired shape after filling, there is no need to process it further, and the box 15 is the molding die 1
Since it is supported by Nos. 1 and 12, it is not deformed by the filling pressure. Therefore, the heat insulating box 10 is
It can be easily and accurately formed into a complicated shape.

When the heat insulating box 10 is used as a heat insulating structure constituting an outer frame of a refrigerator, as shown in FIG. 1, two iron plates of a condenser and a dryer are provided on the back surface of the heat insulating box 10 as a laser. The welded condenser-dryer unit 20 is attached, and the evaporator 21 and the heat-insulating box body 1 provided inside the heat-insulating box body 10 are attached to the one-body body 20.
0 is connected to the compressor 22 provided outside. A vacuum exhaust device 23 is provided outside the heat insulating box 10, and the vacuum exhaust device 23 is connected to the air inlet port 14.
Connected to Then, the vacuum evacuation device 23 is controlled by a cycle timer or a pressure sensor (not shown) so that the degree of vacuum in the hollow portion 16 of the box 15 is constantly increased.

Since a portion indicated by a in FIG. 1 is required to pass an electric cord or the like for connecting the evaporator 21 inside the heat insulating box 10 and the integral body 20 outside the heat insulating box 10, As shown in FIG. 3, a recess 15b is provided in the inner wall 15a of the box 15, the recess 15b is airtightly joined to the inner surface of the outer wall 15c, and a through hole 15d is formed in this joint as shown in FIG. Then, the electric cord or the like can be passed through the through hole 15d with the hollow portion 16 sealed. If the heat insulating box body 10 is configured as in the first embodiment, the conventional vacuum heat insulating pack is not required, and the number of parts and the working / assembling process are greatly reduced.

Further, the heat insulating box 10 is the same as the heat insulating box 10.
Since it has a vacuum heat insulation area almost equal to the total heat transfer area, the heat insulation performance is remarkably improved as compared with the conventional heat insulation box partly using the vacuum heat insulation pack.

The second embodiment shown in FIG. 2 is a heat insulating structure 30 having a double structure. The heat insulating structure 30 is provided in a space 33 between a metal outer box 31 and a synthetic resin inner box 32.
The box 15 of the first embodiment is arranged, and the open cell 31 is filled in the box 15 with the open-cell urethane foam 17 from the air inlet 14 and the outer box 31 is provided in the space 33 between the outer box 31 and the inner box 32. The closed-cell urethane foam 34 is filled from the filling port 31a. Then, the box 15 is evacuated to a vacuum.

As in the second embodiment, the heat insulating box 3
If 0 is configured, in addition to the same functions and effects as in the first embodiment, a heat insulating box body having a double structure is obtained, so that higher heat insulating performance can be obtained. Further, although not shown, a vacuum exhaust device similar to that of the first embodiment is connected to the box 15 of the second embodiment so that the degree of vacuum in the box 15 is constantly increased. .

[0018]

As is apparent from the above description, in the method of manufacturing the heat-insulating box according to the first aspect of the present invention, the case is formed by blow molding the synthetic resin using the molding die, and therefore the flat plate shape is not used. Even if the case has a complicated curved shape, it is possible to easily fill the inside of the case with the open-cell urethane foam.

Further, since the open-cell urethane foam is filled in the case supported by the molding die, the open-cell urethane foam has a desired shape after the filling and does not need to be processed later. Moreover, since the case is supported by the molding die when the open-cell urethane foam is filled, it is not deformed by the filling pressure. Therefore, the heat insulating box can be easily and accurately formed into a complicated shape.

Further, since the case is evacuated and evacuated while the case is filled with the open-cell urethane foam, even if the case has a complicated shape used for a refrigerator, etc. The body as a whole exhibits high vacuum insulation performance and can improve the insulation performance. Further, since a vacuum heat insulating pack having a large number of parts and a large number of processing and assembling steps is unnecessary, it is possible to reduce the cost.

According to a second aspect of the present invention, there is provided a method for manufacturing a heat insulating structure, wherein the heat insulating box body according to the first aspect is arranged in a space between an outer box and an inner box, and further, closed cell urethane foam is provided between the outer box and the inner box. Since it has a double structure filled with, the heat insulation performance can be further enhanced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a heat insulation box body according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a heat insulating structure according to a second embodiment of the present invention.

FIG. 3 is an enlarged view of a portion shown in FIG. 1 before processing.

FIG. 4 is an enlarged view of a portion shown in FIG. 1 after processing.

FIG. 5 is a cross-sectional view showing a step of blow molding the heat insulating box body of FIG.

FIG. 6 is a cross-sectional view showing a step of filling the open-cell urethane foam of the heat insulating box of FIG.

FIG. 7 is a cross-sectional view of a conventional heat insulating box.

[Explanation of symbols]

 10 Insulation Box Body 15 Box 16 Hollow Part 17 Open Cell Urethane Foam 30 Insulation Box Body 31 Outer Box 32 Inner Box 33 Space 34 Closed Cell Urethane Foam

Claims (2)

[Claims] 1. A case is formed by blow molding a synthetic resin using a molding die, and the hollow portion of the case is filled with open-cell urethane foam while being supported by the molding die. A method for manufacturing a heat-insulating box body, which comprises evacuating the interior to create a vacuum. 2. The heat insulating box according to claim 1 is arranged in a space between the outer box and the inner box, and the closed cell urethane foam is filled in the space between the outer box and the inner box. A method of manufacturing a heat insulating structure having a feature.