JPS6337872B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a heat insulating box for a refrigerator or the like, and an object thereof is to prevent sub-effects such as deterioration, cracking, and whitening of the inner box.

Generally, the above-mentioned insulating box body consists of an inner box, an outer box, and a foamed insulation material (hereinafter referred to as urethane) filled in the space between the two boxes, but as a result of direct contact between the urethane and the inner box, the fluorocarbon gas in the urethane This caused deterioration of the inner box, and due to temperature changes, stress was generated due to the difference in expansion and contraction ratio between the inner box and the urethane, causing cracks in the urethane or the 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 it goes without saying that such a method has poor assembly workability and requires a separate process. An air layer is formed between the inner box and the inner box, which deteriorates the insulation performance, and deterioration of 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.

Fig. 1 shows a heat insulating box 1 of a refrigerator, which includes an outer box 2 made of metal, an inner box 3 made of synthetic resin, and both boxes 2,
3 and a foamed urethane (foamed heat insulating material) 4 filled in the space A between the holes.

2 to 4 show the manufacturing process of this heat insulating box 1. That is, first, outer box 2 and inner box 3
are connected at their respective opening edges to form a sealed space A between both 2 and 3. Incidentally, 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 assembled in this manner are set in a jig (not shown) with the opening side facing downward. (FIG. 2) Next, a gas containing a large amount of fine particles 7, 7, such as soot, is injected from one of the injection ports 5 through the nozzle 8 as shown in FIG. 3, and is caused to flow out from the other injection port 6.
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 urethane 4 is injected from 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 fluorocarbon gas contained therein are directly injected, as shown in FIG. Do not touch inner box 3.

The characteristics of the fine particles 7 for adhering the fine particles 7 to the inner box 3 as described above include a) being an adhesive or sticky substance to at least the inner box 3;
(b) It must be included in the air flow (the gas containing the fine particles 7) and flow easily, that is, it must be light.

As an experimental example of injection of fine particles 7, kerosene was partially heated and then injected. At this time, the gas is about 50
The temperature was ~60°C, the soot content was approximately 20%, and the injection process continued for approximately 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 filling the foam insulation material, a gas containing fine particles that do not react with fluorocarbon gas is injected, and the fine particles adhere to the inner box. Deterioration of the inner box due to fluorocarbon gas in the material, cracking and whitening 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. , it is possible to prevent problems such as whitening of the inner box. In addition, since particulate-containing gas leaks from areas with poor sealing properties between the inner and outer boxes, it is possible to check in advance for areas with poor sealing properties, which also helps prevent leakage of the insulation material. Furthermore, compared to the case where a film or the like is attached to the inner box, the assembly work is easier and the defect rate is lower.

[Brief explanation of the drawing]

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... Outer box, 3... Inner box, 4... Urethane (foamed insulation), 7... Soot (fine particles).

Claims (1)

[Claims] 1 A sealed space is constructed by combining an inner box and an outer box,
A gas containing fine particles that do not react with fluorocarbon gas is injected into this sealed space, and after the fine particles are attached to the entire surface of the inner box that comes into contact with the foam insulation material such as urethane, the foam insulation material is placed in the sealed space. A method of manufacturing a foamed insulation box.