JPH08247636A - Heat-insulated box - Google Patents

Abstract

PURPOSE: To increase the volumetric efficiency and prevent rigid urethane foam from cracking at corners due to sharp temperature changes by providing triangular prisms or elastic sheets on insulating-material contact surfaces at the corners between the upsides and sides of the inner box and the foamed insulating material. CONSTITUTION: Foamed insulating material 10 of nearly-spherical rigid urethane foam is filled between outer and inner boxes 2 and 3. Triangular prisms 8 of foamed styrol are adhered onto insulating-material contact surfaces of the outer box 2 at the corners between the upsides and sides of the inner box 3 and the foamed insulating material 10 with a double-sided adhesive tape or adhesive 9 such as hot-melt adhesive. Elastic sheets 11 such as closed-cell foamed flexible urethane foam are stucked on corners 5 of the inner box 3 with adhesive 9. Thereby, rigid urethane foam of an insulated box, that uses the inner box 3 with the corners 5 rounded in a short radius, does not crack even under sharp temperature changes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat insulating box used for refrigerators, showcases and the like.

[0002]

2. Description of the Related Art In recent years, due to space saving, refrigerators having a large volume inside the refrigerator with respect to the external dimensions of the refrigerator, so-called large volumetric efficiency, are mainstream, and the inside of the refrigerator is large, and it seems that the refrigerator feels refreshed. Designs in which the radius R of the corner portion of the inner box is made as small as possible are becoming mainstream.

An example of the conventional heat insulating box described above will be described below with reference to the drawings. FIG. 7 shows a conventional heat insulating box. First, reference numeral 1 is a heat-insulating box, and the heat-insulating box 1 is composed of an outer box 2 formed by bending a steel plate, an inner box 3 made of plastic, and a hard urethane foam 4 filled in a box shell formed between the two boxes. It is configured.

Further, 5 is a corner portion of the inner box in which the radius R is reduced so that the inside of the refrigerator looks large and a clean feeling is obtained in order to increase the volumetric efficiency. Generally, it is often 15 mm or less.

FIG. 8 is a vertical sectional view of the heat insulating box. 6 is air bubbles of flattened urethane foam, 7
Is an approximately spherical rigid urethane foam. In the rigid urethane foam, when the wall thickness changes abruptly during fluid foaming, or when the traveling direction changes abruptly, the bubbles become flat as in 6.

[0006]

However, in the heat-insulating box body 1 constructed in this way, it is used in a situation where the temperature changes drastically, for example, in the case of a refrigerator, it is stored in a warehouse at 30 ° C. or more during the day and −10 ° C. at night. When it is cooled to the vicinity, or when the refrigerator is manufactured and shipped and transported to a cold region, the rigid urethane foam 4 cracks in the corner portion 5 of the heat insulating box 1,
When the refrigerator is operated, there is a problem in that the surface of the outer box 2 is exposed at the corner portion 5 of the heat insulating box 1 in which cracking occurs and the heat insulating performance of the hard urethane foam 4 is partially deteriorated.

The mechanism of cracking in the hard urethane foam 4 at the corner 5 of the heat-insulating box 1 will now be described.

The materials for the outer box 2 and the inner box 3 are steel plate and A, respectively.
When using BS, the linear expansion coefficient of the constituent materials of the heat insulating box 1 is shown in Table 1.
It is like this, and it differs greatly between each material. When the heat insulating box 1 using this material is cooled from room temperature to −30 ° C., the heat insulating box 1 changes as shown in FIG. 9 due to the difference in linear expansion coefficient of each material.

[0009]

[Table 1]

When the heat insulating box 1 is deformed as shown in FIG. 9, stress concentrates on the R portion 5 at the corner of the inner box 3 and the smaller R becomes, the larger the stress becomes. Further, the rigid urethane foam 4 tries to shrink more than the outer box 2 and the inner box 3 due to the difference in linear expansion coefficient, and the stress in the corner portion 5 of the heat insulating box body 1 in which the bubble is flat and the tensile strength is weaker than the spherical part The crack occurred from the inner box side, which took the maximum.

In view of the above problems, the present invention provides a rigid urethane foam having a large volumetric efficiency and a sharp temperature change even if the corner portion R of the inner box is reduced so that the inside of the container looks large and feels clean. The object of the present invention is to provide a heat-insulating box that does not crack.

[0012]

[Means for Solving the Problem] In order to solve this problem,
The heat insulating box body of the present invention comprises an inner box, a foamed heat insulating material, and an outer box in which triangular prism members are arranged on the heat insulating material contact surfaces at the top and side corners.

Further, it comprises an outer box, a foamed heat insulating material, and an inner box in which a resilient sheet is arranged on the heat insulating material contact surface at the corners of the top and side surfaces.

Further, it comprises an outer box, a foamed heat insulating material, and an inner box in which open-celled soft urethane foam is arranged on the heat insulating material contact surface at the corners of the top and side surfaces.

Further, it comprises an outer box, a foamed heat insulating material, and an inner box in which steel plates are arranged on the top surface or the side surfaces or both the top surface and the side surfaces.

Further, a V-shaped reinforcing member is arranged at the fitting portion of the outer box and the inner box at the corners of the outer box, the foamed heat insulating material, the inner box, and the top and side surfaces. .

[0017]

According to the present invention, since the hard urethane foam is smoothly filled even in the corner portion of the heat insulating box by the above-mentioned constitution, the bubbles of the hard urethane foam become almost spherical and the tensile strength is not lowered, and R
The effect is that the rigid urethane foam does not crack even if a rapid temperature change is applied to the heat-insulating box body using the small inner box.

Further, since the elastic sheet can absorb the stress applied to the corner portion of the inner box, even if abrupt temperature change is applied to the heat insulating box body using the inner box having a small R at the corner portion. The effect is that the rigid urethane foam does not crack.

In addition, since the rigid urethane foam is impregnated in the open-celled soft urethane foam to form a hard skin having a small linear expansion coefficient, the heat insulation box body using the inner box having a small R at the corner portion is subjected to a sudden temperature rise. The effect is that even if a change is applied, the rigid urethane foam does not crack.

Further, since the hard urethane foam in the portion where the steel plate is arranged in the inner box is sandwiched between the steel plates, there is no deformation of the wall surface of the heat insulating box due to the difference in linear expansion coefficient, and the heat insulation The deformation of the box is small, the stress applied to the corner is small, and the corner R
The effect is that the rigid urethane foam does not crack even if a rapid temperature change is applied to the heat-insulating box body using the small inner box.

Further, since the V-shaped reinforcing member prevents the heat insulating box from being deformed, the stress applied to the corner is reduced,
There is an effect that cracking of the rigid urethane foam does not occur even when a rapid temperature change is applied to the heat insulating box body using the inner box having the small R in the corner portion.

[0022]

1 to 6 show a heat insulation box body according to an embodiment of the present invention. The same components as those of the conventional example described with reference to FIGS. Omit it.

A first embodiment of the present invention will be described with reference to FIG.
In the above, reference numeral 8 is a member made of styrofoam or the like which is adhered to the heat insulating material contact surface of the outer box 2 with an adhesive 9 such as a double-sided tape or hot melt into a triangular prism. It is desirable that the size of the triangle be a = b because the cells of the rigid urethane foam can be made spherical. Numeral 10 is a substantially spherical rigid urethane foam.

The second embodiment will be described. In FIG. 2, 11 is the elasticity of a closed cell soft urethane foam or the like adhered to the heat insulating material contact surface of the inner box 3 with an adhesive 9 such as double-sided tape or hot melt. It is a flexible sheet. The elastic sheet 11 can absorb the stress applied to the corner portion 5 of the inner box 3.

Further, to explain the third embodiment, in FIG. 3, 12 is a hard material such as open-celled soft urethane foam adhered to the heat insulating material contact surface of the inner box 3 with an adhesive 9 such as double-sided tape or hot melt. It is a foam with open cells that can be impregnated with urethane foam. The rigid urethane foam 4 can be impregnated into the foam 12 having the open cells to form a hard skin having a small linear expansion coefficient.

To explain the fourth embodiment, reference numeral 13 in FIG. 4 denotes a steel plate adhered to the heat insulating material contact surface of the inner box 3 with an adhesive 9 such as a double-sided tape or hot melt. Inner box 3
Since the hard urethane foam 4 in the portion where the steel plate 13 is arranged is sandwiched between the steel plates 13 and 13, the heat insulating box 1 is not deformed due to the difference in linear expansion coefficient, but is deformed as the heat insulating box 1. Is smaller and corner 5
It is possible to reduce the stress applied to.

The steel plates 13 on the wall surface may be arranged on the top surface or the side surfaces, but if they are arranged on both the top surface and the side surfaces, the deformation of the heat insulating box 1 can be further reduced.

Further, to describe the fifth embodiment, FIG. 5 is a front view of the heat insulating box 1 and shows a portion where the reinforcing member 14 is arranged by a dotted line. FIG. 6 is a sectional view of the fitting portion between the outer case 2 and the inner case 3. Reference numeral 14 is a V-shaped reinforcing member 14 arranged at a fitting portion between the outer box 2 and the inner box 3 at a corner portion 5 between the top surface and the side surface, which is plated with a strong metal such as iron so as not to rust. is there.

The reinforcing member 14 is the second flange 15 of the outer box 2.
It is firmly attached to by welding. Since the V-shaped reinforcing member 14 prevents the heat insulating box body 1 from being deformed, the stress applied to the corner portion 5 can be reduced.

[0030]

As is apparent from the above description, the heat-insulating box body according to claim 1 of the present invention comprises the inner box, the foam heat-insulating material, and the triangular prism member on the heat-insulating material contact surface at the corners of the top and side surfaces. By the configuration consisting of the outer box that is arranged, the rigid urethane foam is smoothly filled even at the corners of the heat insulating box, so the bubbles of the rigid urethane foam become almost spherical and the tensile strength is not reduced, It is effective in that the rigid urethane foam does not crack even if a rapid temperature change is applied to the heat insulating box body using the inner box having a small R.

The heat-insulating box body according to claim 2 is an outer box,
Due to the configuration of the foam insulation material and the inner box that has the elastic sheet on the contact surface of the heat insulation material at the corners of the top and side surfaces, the elastic sheet exerts stress on the corner portion of the inner box. Since it can absorb R,
The effect is that the rigid urethane foam does not crack even if a rapid temperature change is applied to the heat-insulating box body using the small inner box.

The heat-insulating box body according to claim 3 is an outer box,
Due to the configuration of the foam insulation material and the inner box in which the open-cell soft urethane foam is placed on the heat-insulating material contact surfaces at the corners of the top and side surfaces, the open-cell soft urethane foam contains hard urethane foam. Since a hard skin with a small penetrating linear expansion coefficient is formed, the rigid urethane foam does not crack even when a sudden temperature change is applied to the heat insulating box body using the inner box with a small corner radius R. There is.

The heat-insulating box body according to claim 4 is an outer box,
By approaching the structure consisting of foam insulation and an inner box with steel plates on the top or side or both top and side,
The hard urethane foam in the part where the steel plate is placed in the inner box has a structure sandwiched between steel plates, so there is no deformation of the wall surface of the heat insulating box due to the difference in linear expansion coefficient,
The deformation of the heat insulation box becomes small, the stress applied to the corners becomes small, and the rigid urethane foam cracks even if a sudden temperature change is applied to the heat insulation box using an inner box with a small corner radius R. There is no effect.

The heat-insulating box 5 according to the present invention has a V-shaped outer box, a foamed heat insulating material, an inner box, and a V-shaped fitting portion between the outer box and the inner box at the corners of the top and side surfaces. Since the V-shaped reinforcing member prevents the heat insulating box from being deformed, the stress applied to the corner portion is reduced, and the heat insulating box body using the inner box with a small corner R is formed. The effect is that the rigid urethane foam does not crack even if a sudden temperature change is applied.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a heat insulating box according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a heat insulation box body according to a second embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view of a heat insulating box according to a third embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view of a heat insulating box according to a fourth embodiment of the present invention.

FIG. 5 is a front view of a heat insulating box in a fifth embodiment of the present invention.

FIG. 6 is a sectional view of a fitting portion between an outer box and an inner box of a heat insulating box according to a sixth embodiment of the present invention.

FIG. 7 is a perspective view of a conventional heat insulating box.

FIG. 8 is a vertical cross-sectional view of a conventional heat insulating box.

FIG. 9 shows the state of deformation when the conventional heat insulation box is cooled to −30 ° C.

[Explanation of symbols]

 1 Insulation Box 2 Outer Box 3 Inner Box 4 Foam Insulation 5 Corner of Inner Box 9 Triangular Column Member 11 Resilient Sheet 12 Open Cell Soft Urethane Foam 13 Steel Plate 14 V-Shaped Reinforcing Member

Claims (5)

[Claims] 1. A heat insulating box body comprising an inner box, a foamed heat insulating material, and an outer box in which triangular prisms are arranged on the heat insulating material contact surface at the corners of the top and side surfaces. 2. A heat insulating box body comprising an outer box, a foamed heat insulating material, and an inner box in which a resilient sheet is arranged on the heat insulating material contact surface at the corners of the top and side surfaces. 3. A heat-insulating box body comprising an outer box, a foamed heat insulating material, and an inner box in which open cell soft urethane foam is arranged on the heat insulating material contact surface at the corners of the top and side surfaces. 4. A heat insulating box body comprising an outer box, a foamed heat insulating material, and an inner box in which steel plates are provided on the top surface or side surfaces or both the top surface and the side surfaces. 5. An insulating box having an outer box, a foamed heat insulating material, an inner box, and a V-shaped reinforcing member provided at a fitting portion between the outer box and the inner box at a corner portion between a top surface and a side surface. body.