JPS58158478A - Manufacture of heat insulating box body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a method of manufacturing a heat insulating box for a refrigerator, etc., and is aimed at preventing adverse effects such as deterioration, cracking, and whitening of the inner box.

In general, the above-mentioned insulating box body is made of foamed insulation material (hereinafter referred to as urethane) filled in the inner box, outer box, and the space between the two boxes.Due to deterioration of the urethane and temperature changes, stress due to the difference in expansion and contraction rate of the inner box and urethane is generated. There were occurrences of cracking in the urethane or inner box, and whitening of the inner box.

In order to solve this problem, it has been proposed to attach a plastic film to the inner box, but such a method has poor assembly workability and requires a separate process. An air layer is formed between the product and the box, which deteriorates the insulation performance, and deterioration in quality is unavoidable due to peeling during the assembly process.

The present invention provides a novel manufacturing method capable of eliminating such drawbacks, and one embodiment thereof will be described below with reference to the accompanying drawings.

Figure 1 shows an insulated box body 1 of a refrigerator, and a metal outer box 2.
and the inner box 3 made of synthetic resin, and the space A between these two boxes 2゜3.
It is composed of urethane (foamed heat insulating material) 4 which is filled and foamed inside.

2 to 4 show the manufacturing process of this heat insulating box 1. That is, first, the outer box 2 and the inner box 3 are connected at their respective opening edges to form a sealed space A between them. A pair of urethane injection ports 5 and 6 are pre-drilled on the back side of the outer box 2. Then, both boxes 2 and 3 combined in this way are placed with a jig (not shown) with the opening side facing downward.
Set inside. (Fig. 2) Next, fine particles such as soot 7°7...
A gas containing a large amount of . . . is injected through the nozzle 8 as shown in FIG. At this time, the fine particles 7, 7, . . . adhere to the inner box 3.

At this time, if the sealing performance between the inner box 3 and the outer box 2 is poor, the particulates 7, 7, .

After that, when the urethane and tan 4 are injected through the injection ports 5 and 6 mentioned above, since the fine particles 7, 7... are attached to the inner box 3, the urethane and the urethane inside are injected as shown in Fig. 4. The fluorocarbon gas contained in the inner box 3 does not come into direct contact with the inner box 3.

The characteristics of the particulate particles that cause the particulates 7 to adhere to the inner box 3 as described above include a) being adhesive or sticky at least to the inner box 3; As an experimental example of injection of fine particles 7, kerosene was injected by incomplete combustion. At this time, the gas temperature was about 5° to 60° C. and contained about 20% soot, and the injection process continued for about 30 seconds. As a result, it was found that soot adhered almost uniformly to the surface of the inner box 3.

As is clear from the above explanation, according to the present invention, before the foam insulation material is injected and filled, a gas containing fine particles that do not react with fluorocarbon gas is injected to cause the fine particles to adhere to the inner box. Deterioration of the inner box due to fluorocarbon gas in the material, cracking, whitening, etc. of the inner box due to this, and cracking of the insulation material and inner box due to stress caused by the difference in expansion and contraction ratio between the inner box and the foam insulation material due to temperature changes. , problems such as whitening of the inner box can be prevented. In addition, since particulate-containing gas leaks from areas where the inner and outer boxes have poor sealing properties, it is possible to check in advance for areas with poor sealing properties, which also helps prevent insulation material leakage.

Furthermore, compared to the case where a film or the like is pasted onto the inner box, assembly is easier and the defect rate is lower.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of a heat insulating box produced by a manufacturing method according to an embodiment of the present invention, and FIGS. 2 to 4 are sectional views of each assembly process by the same manufacturing method. 2...0・Outer box, 311@11...Inner box, 4...0
... Urethane (foamed insulation material), 7... Soot (fine particles). Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (1)

[Claims] The inner box and the outer box are combined to form a sealed space, and a gas containing fine particles that do not react with fluorocarbon gas is injected into the sealed space to cover the entire surface of the inner box that comes into contact with the foam insulation material such as urethane. A method for producing a heat insulating box body, in which after fine particles are attached, a foamed heat insulating material is injected into the closed space and foamed.