JPS6045352B2 - Manufacturing method of insulation box - Google Patents

Description

[Detailed description of the invention] The present invention uses rigid polyurethane foam as a heat insulating material.
The present invention relates to a method of manufacturing a heat insulating box.

Refrigerators using rigid polyurethane foam as a heat insulator generally employ a method of injecting an undiluted solution into the gap between the outer box and the inner box of the refrigerator and foaming it to generate foam. However, there is an injection method required due to the design specifications of the refrigerator box. That is, for the foaming stock solution, an inexpensive raw material is selected, the density of the allowed foam is lowered, and the foam is filled to the required degree in order to improve the foam performance.

On the other hand, the position where the stock solution is injected is located in a structural part that maximizes the performance of the refrigerator, and is also located at an appropriate position to ensure uniformity of the foam. In other words, the normal liquid injection state is to inject the liquid from the back of the outer box into the gap between the outer box and the inner box, and then release the gas through the gas vent hole provided on the back of the outer box or inner box to form a uniform form. A method is used to generate . However, because the current injection port of the box structure injects and foams from the center of the back side, the stock solution that falls from the injection port is injected into the gap between the outer box and the inner box, and the left and right openings of the gap are injected. The liquid flows along the side toward the ceiling panel and the machine room, and then returns as a foam toward the drop point of the raw solution at the injection port.

As the flow distance of the foam increases in this way, the flow of the foam is inhibited, resulting in non-uniform density and
Bubbles turbulence, gas boards, etc. occur. All of these phenomena cause outer box distortion, so in order to eliminate these phenomena, it is necessary to shorten the flow distance as much as possible, eliminate obstruction of foam flow, and obtain stable foam. The present invention has been made to eliminate such drawbacks, and will be explained below with reference to detailed explanatory drawings to FIG. 3 of the present invention.

1 is an outer box assembly, 2 is an inner box, and 3 is an injection port for the stock solution provided according to the present invention.

4 indicates the flow direction of the foam, and 5
is a gas hole provided on the back of the outer box.

6 is a stock solution injection nozzle, 7 is urethane foam, and 8 is a ceiling board.

To explain the injection method, the stock solution is injected into the injection port 3 from the stock solution injection nozzle 6 with the opening facing downward, and the foam is filled while the gas generated by foaming is removed through the gas vent hole 5. Usually, a method is used in which a gas vent hole 5 is provided in the final filling part so that the foam is completely filled. In general, for urethane foam, foaming in one direction from the point where the stock solution is injected is the most effective foaming method because it produces fewer gas voids and gases, has good liquid flowability, and makes the foam uniform. This allows the foam density to be well balanced and contributes to reducing the amount of filling. As explained above, the present invention provides a space created by combining an outer box and an inner box.
In a heat insulating box formed by filling a foamed heat insulating material by foaming on site, etc., an injection port for the foamed heat insulating material is provided near the longitudinal end of the heat insulating box, and a back plate portion of the end opposite to the fill port is provided. The insulating box body is characterized in that a gas vent hole is formed, the box body is inclined so that the side opposite to the injection port is higher, and the foam insulation material is filled with the back plate facing upward. Because it is a manufacturing method, the injection port is placed near the space created by the outer box ceiling and the inner box ceiling.
By making the foam uniform and eliminating outer box distortion, it has the effect of increasing commercial value. Further, the injected heat insulating material causes the foam to rise from the point where it falls, pushing out the gas in the space between the inner box and the outer box toward the vent hole. Therefore, since the foaming direction of the injected heat insulating material is unidirectional, the foaming time of the heat insulating material is shortened, and the hardening of the heat insulating material during foaming is eliminated.

[Brief explanation of drawings]

Figure 1 is a perspective view of the refrigerator from the rear, Figure 2 is A of Figure 1.
-A sectional view shows the injection method, and FIG. 3 is a BB sectional view of FIG. 1...Outer box assembly, 2...Inner box, 3...Inlet, 4
...Flow direction of the foam, 5.Gas vent hole, 6.
...Stock solution injection nozzle, 7...Urethane foam, 8.
・Ceiling board.

Claims (1)

[Claims] 1. A box body with a space formed by combining an outer box and an inner box, and an insulating box body formed by filling foam insulation material from an injection port provided on the back side of the box body with the back side facing up. An injection port for the foam insulation material is provided in a space formed by the ceiling of the outer box and the ceiling of the inner box, and on the back plate near the ridgeline formed by the ceiling plate and the side plate of the outer box, A method for manufacturing a heat insulating box body, characterized in that a gas vent hole provided at the end opposite to the injection port of the back plate and the box body are inclined so that the gas vent hole is located at a higher position.