JPH042875B2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to SF (STATIONARY)
FIXTURE) relates to a method of manufacturing insulation boxes for refrigerators, etc. using a foaming method.

(B) Prior Art Generally, the S/F foaming method is a method used to manufacture heat insulating boxes for large refrigerators and the like.
In this method, the box body is assembled by connecting both the inner and outer boxes with an annular connecting member, and the bottom wall of the outer box is placed on the outer jig board with the opening facing upward. Lower the inner jig into the inner box, press the inner box with the inner jig, then raise each side plate of the outer jig to press the side walls of the outer box, and use both the inner and outer jigs to press the inner box. After fixing the body, a foaming process is performed in which a foaming agent is injected into the space between the inner and outer boxes and the foam is solidified to form a foamed insulation material. It is removed and moved to the next step with the opening facing upward. Therefore, with the S/F foaming method, there is no need to invert the box when fixing the box with both the inner and outer jigs or after removing both jigs from the box, so the rotation rate of both the inner and outer jigs is reduced. It has the advantage that the foaming process can be carried out quickly.

However, in this foaming method, in order to speed up the growth of the foaming agent injected into the space of the large box, two injection holes are formed at both ends of one side wall of the outer box, and the foaming agent is injected into one side of the space opposite each other. Foaming agent is injected at two points (two places) on the bottom wall of the outer box through both the left and right sections, at both ends of the bottom section far from the injection port, and the air inside the space is injected into the space through the many exhaust holes formed on each side of the connecting material. The foamed insulation material is formed by discharging air and fluorocarbon gas, which is a growth agent for the foaming agent, which is the stock solution of the foamed insulation material such as rigid polyurethane.In the initial stage of foaming, the foamed material is released horizontally from both ends of the bottom area, that is, from the bottom. It grows upward while facing the center of the area, that is, toward the top of both the left and right areas, and merges at the center of the bottom area, and intersects with the blowing agent injection direction in the middle of foaming. Because the foaming agent grows toward the top, the growth of the foaming agent in the front and rear regions tends to be slower than in the left and right regions, and the foamed insulation material at the top of both the front and rear regions of the space forms a so-called nest, resulting in poor foaming.

(c) Purpose of the invention The present invention aims to solve the drawbacks of the prior art.

(d) Structure of the Invention An outer box with an opening at the top in which an inlet and an exhaust port located above the inlet are formed on one side wall, and an inner box with an opening at the top disposed inside the outer box, It is arranged on the inner box side and connected by an annular connecting member with an exhaust port formed on one side facing the exhaust port of the outer box, and consists of bottom, front, rear, left, and right regions. After assembling a box with a space, fix the box with the opening surface as the top surface using both the inner and outer jigs, and pour the foaming agent, which is the stock solution of the foam insulation material, from the injection port into the bottom of the space far from the injection port. A method for producing a heat insulating box body in which a foamed heat insulating material is formed by injecting air into the back of the area and exhausting the air in the space from both the exhaust ports of the outer box and the connecting material, which are the final foaming points.

(E) Embodiments of the Invention Reference numeral 1 shown in FIGS. 1 to 3 is a box body, which has an inner box 2 made of metal with an open top surface and an outer box 3 made of metal with an open top surface. , and an annular connecting member 4 made of resin that interconnects both the inner and outer boxes. The inner box is composed of a bottom wall 2A and four side walls 2B to 2E (front, rear, left and right) rising from the periphery of the bottom wall, and flanges 2F to 2I are provided at the upper end of each wall along one end edge of the connecting member 4. is forming. Also, like the inner box, the outer box has a bottom wall 3A.
It consists of four side walls 3B to 3E on the front, rear, left and right sides rising from the periphery of the bottom wall, and at the upper end of each side wall there are opening end faces 3 on the front, rear, left and right sides extending at right angles inward.
F to 3I, and flanges 3J to 3M are formed, which extend perpendicularly downward from the inner edge of each opening end surface and contact the other edge of the connecting member. The connecting member is made up of front, rear, left and right sides 4A to 4D, and each side has flanges 2F to 2I, 3J to 3M of both the inner and outer boxes 2 and 3, as shown in FIGS. 4 to 6. A protrusion 6 that is interposed therein and defines a groove 5 for storing lead wires, etc., and flanges 2F to 2I, 3J to 3M of the inner box 2 or outer box 3 extending vertically from both ends of this protrusion.
regulating parts 7A and 7B facing each other and regulating the degree of insertion of the protrusion; and flanges 2F to 2I, 3J to 3M extending upward or downward from one end of the regulating parts.
Locking portions 8A and 8B spaced apart from each other are integrally formed.

Reference numeral 9 denotes a space formed by fixing the connecting member 4 to both the inner and outer boxes 2 and 3 with fasteners 10A and 10B such as screws, and a bottom area 9A between the bottom walls 2A and 3A of both boxes. and both side walls 2B-2E, 3B-3
It consists of each area 9B to 9E on the front, back, left and right between E.
Inlet ports 11 and 11 are formed at the center of both ends of the front wall 3B of the outer box 3, and are provided facing both the left and right sections 9C to 9E through the front section 9B of the space 9.
12, 12 are formed in the front wall 3B of the outer box 3 in the same manner as the injection ports, and are a number of exhaust ports arranged in a row, located along the upper edge of the front wall 3B above the injection ports 11, 11. , and is provided so as to face the front area 9B of the space 9. The number of exhaust holes is dense near the center of the upper edge of the front side wall 3B, and sparse near both ends. 13, 13 are a number of exhaust ports formed in a row on the protrusion 6 of the front side 4A of the connecting member 4, facing the front area 9B of the space 9 in the same way as the exhaust ports 12, 12 on the front side wall; Also, like the exhaust ports 12, 12, the number is dense near the center and sparse near both ends. The opening area of this exhaust port is smaller than that of the exhaust ports 12, 12 in the front side wall 3B. 1
4, 14 are the left and right sides 4B, 4 after the connecting member 4
A thin plate-shaped heat insulating sealing material made of closed-cell soft resin such as foamed polyethylene is attached to the regulating parts 7A and 7B of C and 4D, and is attached to each of the left and right flanges 2G and 2H after both the inner and outer boxes 2 and 3. ,2I,3K,3L,3
After M and the connecting member 4, left and right sides 4B, 4C, 4
It is interposed between D. 15 and 16 are the front wall 3B
Inlet ports 11, 11 and exhaust ports 12, 1 are provided on the space 9 side surface of the
It is a self-closing cap made of paper or the like that closes the cap. 17
is an air-permeable sealing material made of open-cell soft resin such as Moltoprene, which is provided on the surface of the protrusion 6 on the space 9 side so as to cover the exhaust ports 13, 13 of the front side 4A of the connecting member 4. Reference numeral 18 shown by a chain line in FIGS. 4 and 5 and a solid line in FIG.
8B after foaming the box 1, the locking part 8A of the connecting member 4,
By engaging with 8B, the connecting member 4 is covered.

As shown in FIGS. 7 to 9, the box body is fixed by both inner and outer jigs 20 and 21, 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 has a core portion 20A forming exhaust passages 22, 22 communicating with the exhaust ports 13, 13 of the connecting member 4.
and an annular portion 20B that holds the open end surfaces 3F to 3I of the outer box 3, and is suspended from a support device (not shown) via an arm 20C so as to be able to rise and fall.
The outer jig includes four side plates 21B, 21B, 21B, 21B, 21B, 21B, 21B, 21B, 21B, 21B, 21B, 21A, 21B, 21A, 21B, 21A, 21B, 21A, 21A, 21B, 21B, 21B, 21B, 21B, 21B, 21B, 21B, 21B, 21B, 21B, 21B, 21B, 21B, 21A, 21A, 21A, 21A, 21A, 21A, 21A, 21A, 21A, 21A, 21A, 21A, 21A, 21A, 21A;
21E, and the front side plate 21B, which faces the front wall 3B of the outer box 3, has an injection port 1.
Injection paths 23, 23 communicating with 1, 11, exhaust port 1
2 and 12 are formed. 25, 25 is an injection gun.

First, the box body 1 is placed with the outer jig 21 with the opening surface as the top surface.
The inner box 2 is held down by the inner jig 20 that descends next, and the outer box 3 is held down by the side plates 21B to 21E of the outer jig 21 that rises. Each side wall 3B to 3E is pressed and fixed. After fixing the box body 1, the injection guns 25, 25 are passed through the injection channels 23, 23 and the injection ports 11, 11 as shown in FIGS. 7 and 8, and a foaming agent W such as a hard polyurethane stock solution is poured into As shown, it passes through both the left and right areas 9D and 9E of the space 9 and is injected at two points at the back of the bottom area 9A, that is, at both ends of the bottom area 9A on the rear area 9C side. In the early stage of foaming, the injected foaming agent W grows radially and joins both sides, and first, it flows into the rear area 9C.
Then, as shown in FIG. 9, in the middle stage of foaming, the bottom region 9A, both left and right regions 9D, 9E grow toward the front region 9B, and in the late stage of foaming, they merge from the three directions to form the front region. The self-closing caps 15 and 16 are closed one after another by growing upward from below 9B. During this time, the foaming agent W is used for cream time that changes from liquid, gel time that slows down the growth rate due to foam,
After passing through a tax-free time in which the adhesive strength is weakened by foam and a for-time in which growth stops and solidification occurs, the foamed heat insulating material W shown in FIGS. 10B and 11 is obtained. On the other hand, as the foaming agent W grows, the air in the space 9 (including the front gas) is affected by the foaming pressure.
Inlet ports 11, 1 as shown by the arrows in Figure and Figure 10 A
1. Gradually pushed out from both exhaust ports 12, 12, 13, 13. After forming the foamed heat insulating material W, the desired heat insulating box 1 can be obtained by removing both the inner and outer jigs 20 and 21.

According to this manufacturing method, the blowing agent W is injected 1
Inject into the bottom area 9A of the space 9 far from the inlet 11, 11 and both exhaust ports 12, 1.
In order to make the front area 9B where the foams 2, 13, and 13 face the final foaming area, the foaming agent W in a tax-free state is filled into the front area 9B, and the injection ports 11, 11, both exhaust ports 12, 12 ,13,13
There is little foam leakage from the foam insulation material, and even if it leaks, it can be easily removed because the adhesive strength of the foam insulation material is weak. Since the air in the space 9 is divided into inward and outward directions and discharged to the outside, not only does the rise of the blowing agent W not occur unevenly in the final foaming zone, but also a large eddy flow of air occurs at the corners of the final foaming zone. As a result, air venting becomes smoother and the growth of the foaming agent W improves, making the foam insulation material
It is possible to prevent the formation of so-called cavities due to poor foaming of W'.
In addition, by making the opening area of the exhaust ports 13, 13 of the connecting member 4 smaller than the exhaust ports 12, 12 of the outer box 3, the amount of leaking foam cross-sectional heat material on the inner box 2 side can be reduced from that on the outer box 3 side. By making it smaller, it is possible to save time and effort in removing leaking foam insulation material.

(F) Effect In order to make the front area of the space facing the inlet, exhaust port, and connecting material exhaust port of the outer box the final foaming area, the foaming agent in a tax-free state whose adhesive force has been weakened by the foam is applied to the front area. As a result,
Foam leakage from the inlet and both exhaust ports is reduced, and even if leakage occurs, the adhesive strength of the leaked foam insulation material is weak, making it easier to remove the leaked foam insulation material after the foaming process is completed. Since the air in the space is divided into inward and outward directions and discharged upward and outward from both exhaust ports, which serve as foaming points, the rise of the foaming agent is uneven and large vortices are generated in the air in the space. As a result, the air can be vented smoothly, the foaming agent can grow very well, and the formation of cavities in the foamed heat insulating material near the final point of foaming can be prevented.

[Brief explanation of drawings]

The drawings show an embodiment of the method for manufacturing a heat insulating box according to the present invention, FIG. 1 is a perspective view of the box, and FIG. 2 is a perspective view of the box.
A' cross-sectional view, Figure 3 is a cross-sectional view of Figure 1 B-B', Figure 4
The figure is an enlarged view of FIG. 3C, FIG. 5 is an enlarged view of FIG. 3D, and FIG.
Fig. 7 is a perspective view of the box fixed with both the inner and outer jigs, Fig. 8 is a sectional view taken along the line E-E' in Fig. 7, and Fig. 9 is a sectional view taken along Fig. 7 F-
F' sectional view, FIGS. 10A and 10B are longitudinal sectional views of essential parts showing the growth of the foaming agent at the final foaming point, and FIG. 11 is a longitudinal sectional view of the heat insulating box. 1... Box body, 2... Inner box, 3... Outer box, 4...
Connecting material, 9... Space, 11, 11... Inlet, 1
2, 12, 13, 13...exhaust port, W...foaming agent.

Claims (1)

[Claims] 1. An outer box with an opening at the top in which an inlet and an exhaust port located above the inlet are formed on one side wall, and an inner box with an opening at the top disposed inside the outer box. , connected by an annular connecting member disposed on the inner box side and having an exhaust port formed on one side adjacent to and facing the exhaust port of the outer box from the bottom, front, rear, left, and right areas. After assembling a box with a space of A method for producing a heat insulating box body, which forms a foam heat insulating material by injecting air into the depths of a bottom area and exhausting air in the space from both exhaust ports of an outer box and a connecting member. 2. The method of manufacturing a heat insulating box according to claim 1, wherein the opening area of the exhaust port of the connecting member is smaller than that of the exhaust port of the outer box.