JPS6344529B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a heat insulating box body in which a part that acts as a flow path resistance of a foam heat insulating material during the growth process of the heat insulating material is attached to the wall surface of one of the inner and outer boxes. The purpose of this is to prevent air bubbles generated in the heat insulating material during the growth process from deforming the wall surface facing the wall surface on which the parts are attached due to the temperature drop after foaming.

Examples of the present invention will be described below with reference to the drawings.
1 shown in Fig. 1 is an insulated box body such as a storage warehouse, which is composed of a storage section A with an opening for storing and taking out products on the top surface, and a mechanical section B in which a compressor, condenser, etc. (not shown) are installed. As shown in Fig. 2, the storage section includes an inner box 2 made of metal, an outer box 3 made of metal or a synthetic resin resistant to chlorofluorocarbons such as ABS, and a rectangular resin box 3 that connects the upper ends of both the inner and outer boxes. A decorative frame 4 and a space 5 formed by the boxes and the decorative frame.
A meandering cooler 7 is constructed of a foamed heat insulating material 6 made of hard polyurethane or the like which is filled with foam, and is arranged in a meandering manner on the outer surface of the inner box 2, that is, on the side of the heat insulating material. It is for cooling. Reference numeral 9 denotes a refrigeration component such as a header for collecting the refrigerant returned from the cooler, which is attached to one side wall surface 2a of the inner box and buried in the foam insulation material 6 together with the cooler.

Next, a method for manufacturing the storage section A having such a structure will be explained with reference to FIG.

An inner box 2 has a cooler 7 attached to an outer circumferential wall in advance, a component 9 is attached to one side wall surface 2a of the circumferential wall, and a reinforcing plate 10 such as a metal plate is attached to a wall surface 3a opposite to the wall surface 2a on which the component is attached. The male jig 1 is heated so that the decorative frame 4 faces downward after connecting the outer box 3 which is placed in close contact with the outer box 3 with a decorative frame 4 so as to form a space 5.
1, the inner box 2 is fixed, and then the foaming stock solution is injected into the space 5 through injection holes 13 at both ends of the bottom wall of the outer box 3.
After injection, the injection hole 13 is closed with a plug 15 and the outer box 3 is fixed with a heated female jig 12. The foaming solution injected into the space 5 gradually foams and grows due to chemical changes, and the air and fluorocarbon gas in the space 5 are pushed out from the plurality of small holes 14 in the center of the bottom wall of the outer box 3 as shown by the arrows. As a result, the space 5 is filled with foam and solidified to form a foamed heat insulating material 6, thereby completing the production of the storage section A.

In the above foaming process, the component 9 acts as a flow path resistance for the growing foamed insulation material 6, so the insulation material in the component side area of the space 5 grows slower than the insulation material in the other side area, making it difficult for air to escape. , the air bubbles generated in the insulation material cannot be completely removed and remain in the insulation material as residual air, resulting in air pockets (referred to as voids) between the foam insulation material 6 and the reinforcement board 10 as the insulation material adheres to the reinforcing board 10. ) 16. This air pocket gradually contracts due to the temperature drop after foaming in storage section A is completed, for example, the temperature drop until the insulation material returns to room temperature immediately after foaming, or the temperature drop that occurs during operation of the refrigeration cycle, resulting in a small volume and negative pressure. Although the reinforcing plate 10 is tried to be sucked toward the foamed heat insulating material, the strength of the reinforcing plate 10 is greater than this suction force, so no dent is created in the reinforcing plate 10. Incidentally, as shown in FIG. 4, in a failure example in which the reinforcing plate 10 was not provided, the wall surface 3a of the outer box 3 was dented toward the heat insulating material due to the suction force.

As described above, in the present invention, during the growth process of the foam insulation material, a component that acts as a flow path resistance of the insulation material is attached to one wall surface of both the inner and outer boxes, a reinforcing plate is provided on the wall surface opposite to this wall surface, and the inside and outside This is a method for manufacturing an insulating box in which a foaming solution is injected between both boxes, and the air bubbles generated in the insulating material during the growing process are left as air pockets between the insulating material and the reinforcing plate. The reinforcing plate can reliably prevent the deformation of the wall surface due to the volume change of air bubbles contracted due to temperature drop during operation of the refrigeration cycle, and it is possible to provide an insulated box that does not produce defective products.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a heat insulating box completed by the method of the present invention, Fig. 2 is a longitudinal sectional view of the same foaming process, Fig. 3 is a longitudinal sectional view of the main part after foaming, and Fig. 4 is a perspective view of the heat insulating box completed by the method of the present invention. FIG. 4 is a vertical cross-sectional view corresponding to FIG. 3 in an example of failure up to this point. 2...Inner box, 3...Outer box, 6...Foam insulation material,
9... Parts, 10... Reinforcement plate, 16... Air pocket.

Claims (1)

[Claims] 1. During the growth process of the foam insulation material, a component that acts as a flow resistance for the insulation material is attached to one wall of both the inner and outer boxes, a reinforcing plate is installed on the wall facing this wall, and the foam is inserted between the inner and outer boxes. A method for producing a heat insulating box body by injecting a stock solution and allowing air bubbles generated in the heat insulating material during the growth process to remain between the heat insulating material and the reinforcing plate as air pockets.