JPH02290486A - Manufacture of heat insulating box body - Google Patents

Abstract

PURPOSE:To enable sharp reduction of the cost of a jig by a method wherein most of a space formed by outer and inner boxes is packed with a free-foaming heat insulating material, and after this heat insulating material is almost set, the residual space is packed with a regulated-foaming heat insulating material. CONSTITUTION:An inner box 1 and an outer box 2a are assembled and a heat insulating material 3a of urethane is injected and foamed in a state wherein a back plate 2b is not fitted. Since foaming is effected in an open space on the occasion, a foaming pressure does not rise almost at all, and a foaming jig is dispensed with when the strength of the outer box 2a and the inner box 1 is large. Even when the strength is small, the back plate 2b is incorporated after the heat insulating material 3a of urethane is set, and a heat insulating material 3b of urethane is foamed in the residual space by using an internal jig 8 and an external jig 9. By this method, foaming jigs can be simplified and the cost of a heat insulating box body can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing a heat insulating box, and more specifically to simplifying a foaming jig in the process of filling a foam heat insulating material.

3. Prior Art FIG. 3 is an external perspective view of a domestic refrigerator-freezer, which is constructed by filling a space formed by an inner box 1 and an outer box 2 with a urethane foam heat insulating material.

3. Prior Art FIG. 3 is an external perspective view of a domestic refrigerator-freezer, which is constructed by filling a space formed by an inner box 1 and an outer box 2 with a urethane foam heat insulating material.

FIG. 4 is a vertical cross-sectional view of the main part to explain the filling of the urethane foam insulation material, in which the inner box 1 made of resin and the outer box made of steel plate are assembled, and the t-box body conforms to the inner shape of the inner box 1. It is surrounded by an inner jig 4 and an outer jig 5 that matches the outer shape of the outer box 2.
The urethane injection nozzle 6 was inserted into the space formed by the inner box 1 and the outer box 2 from the back side of the box, and the urethane raw material was injected to fill the insulation material by controlled foaming (foaming in a closed state).

<Problems to be Solved by the Invention> By the way, when the urethane heat insulating material is regulated and foamed in a closed state using this method, the foaming pressure increases, and a strong inner jig 4 and outer jig 5 are required.

Providing a large number of strong foaming jigs (which cost a lot of money) meant higher fixed costs, which led to an increase in the manufacturing cost of the insulating box.

Measures to Solve Problems> Most of the space formed by the outer box and inner box is filled with a free-foaming (foaming in an open state) insulation material, and the remaining space is filled after the insulation material has almost hardened. Fill the space with regulated foam insulation.

Function: Since most of the void formed by the outer box and inner box is filled with free foaming with low foaming pressure, a simple foaming jig is sufficient for that part; If the box is strong, it is not necessary) and the cost of the jig can be significantly reduced.

Example Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a sectional view showing a state in which most of the space formed by the outer box and the inner box is filled with urethane insulation material by free foaming (foaming in an open state). The urethane heat insulating material 3a was assembled and the back plate 2b was not attached, and the urethane heat insulating material 3a was injected and foamed without using a foaming jig.

At that time, foaming is performed in an open space, so the foaming pressure hardly increases.If the outer box and inner box are strong, a foaming jig is not necessary, and even if the strength is low, a simple jig can be used. can.

FIG. 2 is a cross-sectional view showing the state in which the remaining space is filled with heat insulating material by controlled foaming (foaming in the closed state) after the urethane heat insulating material 3a has hardened. Urethane insulation foam 3b is foamed into the remaining space using an external jig 9. At that time, the rL. Since the foaming is regulated in this space, the foaming pressure is considerably increased, and the gap between the urethane insulation material 3a filled earlier and the back plate 2b is completely filled, and the urethane insulation material is filled in the space formed by the inner box 1 and the outer box 2. 8 is completely filled.

Effects> According to the present invention, the foaming jig can be simplified, and the cost of the heat insulating box can be reduced.

[Brief explanation of drawings]

Figure 1 is a sectional view showing a state in which most of the space is filled with free foam insulation, Figure 2 is a sectional view showing the remaining space is filled with regulated foam insulation, and Figure 3 is a refrigerator. FIG. 4 is a vertical cross-sectional view of the main part to explain the conventional method of filling with foamed heat insulating material. Code 1: Inner box, 2: Outer box, 3: Foamed insulation material (8a...free foaming, ab...regulated foaming).

Claims (1)

[Claims] 1. In the step of filling a heat insulating box body by injecting and foaming a foamed heat insulating material into the space formed by the outer box and the inner box, most of the space is filled with free-foamed heat insulating material. 1. A method for producing a heat insulating box, characterized in that the remaining space is filled with a heat insulating material by controlled foaming after the heat insulating material has almost hardened.