JPH0457950B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method of manufacturing a heat insulating box in which the space between the inner and outer boxes is filled with a foamed heat insulating material.

(B) Prior Art The resin foam insulation box shown in the specification and drawings of U.S. Patent No. 3,132,382 includes a mold for molding the resin foam under pressure, and the mold forms a closed cavity. an apparatus comprising a wall having a top wall, the top wall having an injection hole, and a flexible tube attached to the injection hole for injecting foamed resin into the mold; The tube is suspended freely within the mold away from the bottom of the mold, and the tube is hermetically permanently affixed to the rim of the injection hole, the lower end of the tube being suspended by the foam resin during expansion of the mold. It was provided with a configuration that flattened by folding laterally to seal the injection hole when brought into contact.

(c) Problems to be Solved by the Invention In the above-mentioned prior art, the lower end of the flexible tube through which the foamed resin stock solution passes is far away from the bottom of the mold, so that the foamed resin stock solution that has passed through the tube does not flow into the mold. It is then injected into a predetermined position with some of it being diffused within the mold and attached to opposing walls within the mold. For this reason, not only does the stock solution start foaming from the bottom of the mold, but it also starts foaming from the parts that adhere to the opposing walls, and as a result of the foaming of the stock solution that adheres to the walls, it is poured into the bottom. Foaming of the stock solution is inhibited, resulting in significantly non-uniform foam density. That is, partial foaming caused by diffusion of the stock solution causes density variations in the foamed resin within the mold, resulting in problems such as so-called shrinkage in which the walls deform as the foamed resin shrinks. In addition, when the flexible tube comes into contact with the foamed resin at its lower end, it folds horizontally and becomes flat, and it doubles as an injection hole cap that closes the injection hole, so the folded tube is foamed in the mold. Not only does this result in a bulky material that inhibits the growth of the foamed resin near the tube, making it difficult for the foamed resin to circulate around the tube, leading to the formation of a honeycomb area, but also causing the foamed resin near the tube to become stiff due to air remaining inside the tube. There was also the problem that the insulation effect deteriorated. Furthermore, since the flexible tube is folded horizontally when it comes into contact with the foamed resin, if it is installed laterally, that is, in the front-rear direction or the left-right direction,
There is also the problem that the tube bends due to the weight of the stock solution passing through it, making it impossible to inject the stock solution into a predetermined position.

(d) Means for solving the problems The present invention provides an insulating box body in which a foaming solution of a foaming insulating material is injected into the spaces inside and outside the box and solidified by foaming, in which an injection hole is formed in the outer box, and A heat insulating flexible pipe is arranged in the space so that one end opening faces the injection hole, and an injection gun for injecting the stock solution faces the one end opening of the pipe, so that the stock solution is passed through the pipe. After injecting into the space, the injection gun is removed from the injection hole, and the foam is solidified into the space.

(E) Function When the foaming solution of the foam insulation material is injected into the pipe using an injection gun placed facing the opening at one end of the insulating flexible pipe, the foaming solution flows through the pipe to the other end. foaming starts from that position. Since the pipe is flexible, even when foaming an insulating box with a complicated shape, the foaming stock solution can be reliably guided to the desired foaming start location.

The foaming solution enters the pipe and foams, so after foaming is finished, the pipe is also filled with foam insulation, which does not impair the insulation performance of the insulation box. Since the foam insulation material has solidified, the pipe also acts as reinforcement for the insulation box.

(f) Examples Examples of the present invention will be described below based on the drawings.

1 shown in FIGS. 9 to 11 is a box body, and this box body has an inner box 2 made of metal with an opening on the top, an outer box 3 made of metal with an opening on the top, and connects both the inner and outer boxes to each other. It is assembled with an annular connecting member 4 made of resin.
The inner box consists of a bottom wall 2A and four side walls 2B to 2E, front, back, left and right, rising from the peripheral edge of the bottom wall,
Flanges 2BF to 2EF that contact one side of the connecting member 4 are formed at the upper end of each side wall. Also, like the inner box, the outer box is composed of a bottom wall 3A and four side walls 3B to 3E on the front, back, left, and right sides rising from the peripheral edge of the bottom wall. Contacting flanges 3BF to 3EF are formed.
The connecting member is composed of narrow long sides 4A and 4B that face each other on the one hand and wide short sides 4C and 4D that face each other on the other hand, and has a U-shape in longitudinal section. An opening 5 of the box body 1 is defined on the circumferential surface. Reference numeral 6 denotes a space formed by assembling both the inner and outer boxes 2 and 3 by the connecting member 4, which includes a bottom area 6A between the bottom walls 2A and 3A of the two boxes, and a space between the two side walls 2B to 2.
E, front, rear, left and right areas between 3B and 3E 6B to 6E
The thickness of both the front and rear sections 6B, 6C located directly under the long sides 4A, 4B of the connecting member 4 is the thickness of both the left and right sections 6D, located directly under the short sides 4C, 4D.
It is thinner than the thickness of 6E. 7 is the central lower part of the front wall 3B of the outer box 3, and is the bottom area 6 of the space 6.
This is an injection hole formed slightly above A. 8A, 8B are both long sides 4A, 4 of the connecting member 4.
A large number of exhaust holes are formed in B, which face both the front and rear areas 6B and 6C of the space 6. This exhaust hole is located on the long side 4A,
4B is formed so that the number thereof decreases progressively from the center to both ends. 8C and 8D are exhaust holes formed in the inner walls of the short sides 4C and 4D of the connecting member.

14 is a cylindrical pipe attached to the inner surface of the center part of the bottom wall 3A of the outer box 3 with an adhesive tape 15, and is a cylindrical pipe which has heat insulation properties and whose wall surface has a low viscosity, that is, a glossy surface, for example, a flexible pipe. It is made of resin and is arranged so as to be inclined and bent backward so that the rear end is lower than the front end, and as shown in FIG. and its front end extends to the bottom area 6.
It is bent at the border between the bottom area 6A and the front area 6B so as to face the injection hole 7 formed in the front side wall 3B at a position slightly above A with a distance L. . This pipe 14 preferably has a length of 1/2 or more of the depth dimension M of the bottom area 6A of the space 6, that is, the length of the pipe 14 is such that its rear end extends to the vicinity of the injection point of the foaming stock solution, which will be described later. 1
Reference numeral 6 denotes a plate-shaped self-closing cap made of paper or soft resin attached to the inner surface of the front wall 3B of the outer box 3 with adhesive or adhesive tape so as to cover the injection hole 7, and is H-shaped as shown in FIG. Two movable tongue pieces 16 are provided with notches.
A, 16B are formed. Both tongues are pushed open by an injection gun, which will be described later, as shown by the solid lines in Figure 4, and after the foaming stock solution is injected, they return to the state shown by the chain lines due to their own elasticity, and are then expelled by the foaming pressure of the foam insulation material. It is pushed in the direction of the box 3 and closes the injection hole 7.

As shown in FIGS. 1, 2, and 5 to 7, the box is fixed by both inner and outer jigs 9 and 10, which have been heated to an appropriate temperature in advance, and subjected to a foaming operation.
The inner jig is inserted into the inner box 2, and the exhaust hole 8C,
A core portion 9A formed with exhaust passages 11C and 11D communicating with the exhaust hole 8
The annular portion 9B has exhaust passages 11A and 11B that communicate with the exhaust gases 11A and 8B, and is suspended from a support device (not shown) via an arm 9C so as to be vertically movable. Further, the outer jig is a substrate 10 on which the box body 1 is placed.
A, and four front, left, right and left side plates 1 that can be freely moved toward and away from each other.
Consisting of 0B to 10E, outer box 3 of this side plate
An injection path 12 communicating with the injection hole 7 is formed at the lower center of the front side plate 10B facing the front side wall 3B of the injection hole 7 .

First, the box body 1 is placed on the base plate 10A of the outer jig 10 with the bottom wall 3A of the outer box 3 placed on the base plate 10A of the outer jig 10 with the opening 5 facing upward, and then the inner jig 9 that has descended pushes the inner box 2 and the connecting member 4. At the same time, each side wall 3B to 3E of the outer case 3 is held down by each side plate 10B to 10E of the outer jig 10 that has been raised up, and is fixed by the SF foaming method. After fixing the box 1, the injection gun 13 shown in FIGS. 1, 2, and 4 is passed through the injection path 12 and the injection hole 7, and the self-closing cap 1 is closed as shown by the solid line in FIG.
Push open both tongue pieces 16A, 16B of 6 and remove pipe 1.
4, a foaming stock solution W such as a hard polyurethane stock solution is injected through the pipe 14 into the rear center of the bottom area 6A, which is the injection drop point, as shown in FIG. In the early stage of foaming, the injected foaming stock solution W grows radially from the rear center of the bottom area 6A toward the front and both sides, as shown in FIG. 5, and then foams as shown in FIGS. 6 and 7. In the middle stage, it grows toward the upper part of both the front and rear zones 6B, 6C and grows into the pipe 14, and in the late stage of foaming, the growth in the front zone 6B almost catches up with the growth in the rear zone 6C, and during this period, the foaming stock solution becomes a liquid. Cream time, which changes from foam to foam, gel time, which slows down the growth rate due to foam, tack-free time, which weakens adhesive strength, and foam time, which stops growing and solidifies, to form insulation foam.
It becomes W′. On the other hand, as the foamed W grows, the space 6
Due to the foaming pressure, air and fluorocarbon gas inside the pipe 14 pass through the self-closing cap 16, the injection hole 7, and the injection path 12 in the early stage of foaming, and from the early stage to the later stage of foaming, the air and fluorocarbon gas pass through the self-closing cap 16, the injection hole 7, and the injection path 12 in the early stage of foaming. Exhaust hole 8 as shown by the arrow
A, 8B, 8C, 8D and exhaust passages 11A, 11
It is gradually pushed out from B, 11C, and 11D. After forming the foam insulation material W′, both the inner and outer jigs 9 and 1
By removing 0, the insulation box 1' is completed as shown in FIG.

According to this manufacturing method, one end of the bent pipe 14 through which the foaming solution W passes is close to the injection hole 7 with a gap L therebetween, and the other end is close to the point where the foaming solution W is injected and falls. Therefore, the pipe 14, which maintains its internal hollow state even when bent, can prevent the foaming stock solution W from diffusing into the space 6 during injection, and the foaming stock solution W can be injected into a predetermined position. . As a result, foaming of the foaming solution W starts from a predetermined position in the space 6 and its growth becomes good, so that a foamed heat insulating material W' having a uniform foaming density can be formed. Further, since one end of the pipe 14 is close to the injection hole 7 with a gap L, as the foaming stock solution W foams, the foaming stock solution enters the pipe 14 and the air inside the pipe is pushed out. Similarly to the space 6, the foamed heat insulating material W' is filled, and the gap L between the pipe 14 and the injection hole 7 is also filled with the foamed heat insulating material W'. As a result, even if the pipe 14 is placed within the space 6,
There is no problem with the growth of the foaming solution W and the discharge of air, and it is possible to avoid air remaining in the space 6 and the formation of honeycomb portions due to this air remaining. Furthermore, since the pipe 14 is attached to the outer box 3 and filled with foamed heat insulating material W', after foaming, it becomes a reinforcing member for the outer box 3, increasing the strength of the outer box 3 against external shocks. , foam insulation
It serves to prevent shrinkage due to contraction of W′. Furthermore, since the pipe 14 is made of a flexible material, if parts or the like are provided on the outer surface of the inner box 2, the bent portion can be used as a detour by bending the pipe 14 into an appropriate shape. The foaming stock solution W can be injected into a predetermined position.

(G) Effects of the Invention According to the present invention, since the foaming stock solution is injected into the space through the pipe, most of the foaming stock solution is injected into the predetermined foaming start position by preventing the foaming stock solution from spreading within the space. The diffused foaming solution prevents the foaming from the predetermined foaming start position, and there is no air remaining in the space, resulting in smooth foaming operation and foam insulation with uniform density. Obtainable. Since the pipe is flexible, the foaming stock solution can be reliably guided to the desired foaming start location even when foaming an insulating box with a complicated shape.

In addition, since the foaming solution enters the pipe and foams, after foaming is completed, the pipe is also filled with foam insulation material, which does not impair the insulation performance of the insulation box. Provides a reinforcing effect.

[Brief explanation of drawings]

The drawings all show an embodiment of the method for manufacturing a heat insulating box according to the present invention, and FIG. 1 is a sectional view taken along the line A-A in FIG. 3
The figure is an installation diagram of the self-closing cap, Figure 4 is an enlarged vertical sectional view of the main part showing the opening and closing operation of the self-closing cap, Figure 5 is a cross-sectional view taken along the line B-B in Figure 1, and Figure 6 is the line C-- C sectional view, FIG. 7 is a sectional view taken along line D-D in FIG. 1, FIG. 8 is a vertical cross-sectional view of the insulation box, FIG. The sectional view, FIG. 11, is a sectional view taken along line FF in FIG. 2...Inner box, 3...Outer box, 6...Space, 7A, 7B...
Injection hole, 14, 14...pipe, W...foaming stock solution,
W′...Foam insulation material, L...Gap.

Claims (1)

[Claims] 1. In an insulating box body in which a foaming solution of a foaming insulation material is injected into the space between the inner and outer boxes and foamed and solidified, an injection hole is formed in the outer box, and an insulating flexible pipe is connected so that one end opening is connected to the injection hole. An injection gun for injecting the stock solution is placed in the space so as to face the opening at one end of the pipe, and after the stock solution is injected into the space through the pipe, the injection gun is injected from the injection hole. A method for manufacturing a heat insulating box body, in which a gun is removed and foam is solidified in the space.