WO2014021018A1

WO2014021018A1 - Manufacturing method for insulating boxes, insulating boxes, and refrigerators

Info

Publication number: WO2014021018A1
Application number: PCT/JP2013/066968
Authority: WO
Inventors: 剛史永田; 仁史乾; 康哲中西
Original assignee: シャープ株式会社
Priority date: 2012-07-30
Filing date: 2013-06-20
Publication date: 2014-02-06
Also published as: JP2014025671A

Abstract

Provided are a manufacturing method for insulating boxes, and an insulating box and a refrigerator manufactured by way of the manufacturing method for insulating boxes capable of molding, with a good yield rate, insulating boxes that can be fit together precisely during assembly, without the use of complex manufacturing devices or metal molds. The manufacturing method for insulating boxes, wherein an inner box comprising a foam body, an outer box comprising a metal plate, and insulating material between the inner box and outer box are disposed, is characterized by performing, in order: an inner box formation step of disposing the foam body using a fixed jig as a base; an insulating material disposition step of disposing the insulating material on the outside of the inner box; and an outer box bonding step of bonding the outer box to the outside of the insulating material.

Description

Method for manufacturing heat insulation box, heat insulation box and refrigerator

The present invention relates to a method for manufacturing a heat insulating box, a heat insulating box manufactured by the method for manufacturing the heat insulating box, and a refrigerator using the heat insulating box.

In recent years, refrigerators, freezers, and refrigerator-freezers have higher requirements for the dimensional accuracy and appearance quality of the heat insulating box constituting the refrigerator, in addition to the requirements for functional performance such as cooling performance and energy saving performance. In addition, a manufacturing method that meets the above-described requirements is required, and in particular, in the manufacture of heat-insulated boxes, yields are reduced and tact time cannot be shortened, and improvement of the manufacturing method is required.

First, the heat insulation box will be explained. In the heat insulating box, a foamable heat insulating material (for example, urethane foam) is disposed in a space formed between the inner box and the outer box. The outer box is made of a metal plate having a thickness of about 1 mm, the inner box is made of resin with a good appearance, and the metal outer box and the resin inner box itself do not have sufficient strength and heat insulation. . For this reason, in the heat insulation box, the strength and heat insulation necessary for the exterior of the refrigerator are given by the urethane foam filled in the space between the inner box and the outer box.

Next, manufacture of a general heat insulation box will be described. The heat insulating box is formed by fitting the inner box and the outer box together. After injecting urethane foam into the space between the inner box and the outer box, the foam is foamed and filled into the space to form a heat insulating box. At this time, the foaming pressure of urethane is a high foaming pressure of 0.1 kg / cm ² or more. As described above, the inner box and the outer box have a thickness of about 1 mm, and it is difficult to withstand the foaming pressure of urethane foam.

For this reason, urethane foam is injected into the space between the inner box and the outer box in a state where the inner box and the outer box are attached to a mold (jig) having a strength capable of withstanding the foaming pressure of the urethane foam. The method is adopted.

At the time of injection of urethane foam, the blending ratio of materials, filling pressure, temperature, injection amount, etc. are controlled so that the urethane foam filled in the space has the above-described strength and heat insulation.

However, injecting urethane foam, it is necessary to maintain the foaming pressure with a mold until the urethane foam is cured. For this reason, the holding time of about 3 minutes was needed with respect to one metal mold | die for forming a heat insulation box. In particular, in order to cope with a complicated shape and an increase in size, stability is required for the shape, so it is necessary to extend the holding time, and shortening tact is an urgent issue.

For this reason, a method for forming a heat insulating box by combining a plurality of foamed urethane boards as shown in Patent Document 1 (Patent No. 4631544) is effective as a manufacturing technique that does not use a mold.

FIG. 9 is an assembly configuration diagram of the casing 90 of the vending machine disclosed in Patent Document 1. In the vending machine, a plurality of heat insulating panels configured by arranging steel plates to surround the heat insulating material are arranged inside the outer box, and at least one of the heat insulating panels has a vacuum heat insulating panel embedded in the heat insulating material. Has been. By setting it as such a structure, high heat insulation performance can be acquired.

In the figure, the heat insulating panel is assembled by inserting it into the outer box 95 in the order of the heat insulating panel 96a, then the heat insulating panels 96c and 96d, then the heat insulating panel 96e, and finally 96b. Insulating foam foam or the like is affixed to the abutting surfaces of the heat insulating panels. At the final stage of assembly, the abutting surfaces are fixed in a compressed state, and the heat insulating panels are fastened.

Conventionally, foaming heat insulation materials may be used as structural materials as they are, but in this case, even if cut with high precision, due to temperature fluctuations and residual stress after panel manufacture, depending on the standing time, The shape may vary. On the other hand, in patent document 1, the fluctuation | variation of a shape is suppressed by taking the sandwich structure which pinches | interposes panel itself with a metal thin plate material.

Japanese Patent No. 4631544 (registered on November 26, 2010)

However, in the assembly method shown in Patent Document 1, when a plurality of heat insulation panels are combined, if the fitting accuracy is poor, the outer box 95 is tilted, twisted, or a gap is formed in the corner portion inside the outer box. It may open. In order to increase the fitting accuracy, a metal that has been subjected to complicated bending may be disposed at the end of the panel, but there are problems such as an increase in weight and a decrease in yield.

Similarly, even when the size of the panel used for assembly is changed, the outer box 95 may be tilted or twisted, and a gap may be formed in the corner portion inside the outer box, resulting in a problem that the yield is not improved. It was.

Furthermore, when a groove or the like for installing a shelf board in advance is provided in the heat insulation board, there is a problem that the yield is not improved because the position of the shelf board is shifted if the fitting accuracy is poor.

Moreover, as shown in Patent Document 1, when a sandwich structure in which the board itself is sandwiched between metal thin plate materials is taken, the heat insulating board is heavy and difficult to assemble, or the refrigerator inner surface is made of metal. In other words, there are problems such as providing an aesthetically pleasing design or forming a complicated groove shape by forming the inner surface from a resin as in a household refrigerator.

In addition, it is possible to make a heat insulation board combination box by combining heat insulation boards in advance, and insert and bond it to the outer box. In such a method, both the outer box and the heat insulation board combination box are closely attached with high accuracy. It is difficult to do so, and the assembly efficiency decreases.

The present invention has been made in view of such a problem, and the object thereof is to form a heat insulating box with a high yield without using a complicated manufacturing apparatus and mold, and with high fitting accuracy during assembly. An object of the present invention is to provide a heat insulating box body and a refrigerator manufactured by the heat insulating box body manufacturing method and the heat insulating box body manufacturing method.

The manufacturing method of the heat insulation box which concerns on this invention is the heat insulation box by which the heat insulation was arrange | positioned between the inner box comprised from a foam, the outer box comprised from a metal plate, and the said inner box and the said outer box A method for manufacturing a body, wherein an inner box forming step of arranging the foam on the basis of a fixing jig, a heat insulating material arranging step of arranging the heat insulating material outside the inner box, and an outer side of the heat insulating material The outer box bonding step for bonding the outer box is performed in this order.

Further, the fixing jig may be formed according to the dimensions of the inner box.

Further, the inner box forming step may include a step of temporarily fixing the foams together.

Further, the outer box bonding step may include a heating step for bonding.

Further, after the outer box forming step, a molding step of thermoforming the inner side of the inner box may be included.

The heat insulation box according to the present invention is manufactured using the method for manufacturing a heat insulation box according to any one of the above.

The refrigerator according to the present invention is manufactured using the heat insulating box described above.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the heat insulation box which can shape | mold a heat insulation box body with high yield with high fitting precision at the time of an assembly, without using a complicated manufacturing apparatus and metal mold | die, and a heat insulation box body It becomes possible to provide the heat insulation box and refrigerator which were manufactured by the manufacturing method.

It is the refrigerator schematic using a heat insulation box. It is a flowchart which shows the manufacturing method of a heat insulation box. FIGS. 3A, 3B, 3C and 3D are schematic views for explaining a method for manufacturing a heat insulating box. 4E, 4F, 4G, and 4H are schematic views for explaining a method for manufacturing a heat insulating box. 5 (a) and 5 (b) are schematic diagrams for explaining the molding of the inner box. FIGS. 6A and 6B are schematic views for explaining the molding of the inner box. FIGS. 7A and 7B are schematic views for explaining the molding of the inner box. It is a perspective view of a metal mold | die. It is a figure which shows the assembly method of the conventional heat insulation box.

Embodiments of the present invention will be described below with reference to the drawings. In the drawings of the present invention, the same reference numerals represent the same or corresponding parts.

FIG. 1 is a schematic view of a refrigerator using a heat insulating box manufactured by the method for manufacturing a heat insulating box according to the first embodiment. However, the door of the refrigerator 1, refrigeration cycle components such as an evaporator and a compressor, and electrical components such as a control board are not illustrated.

The refrigerator 1 includes an inner box 2, an outer box 3, and a heat insulating board 4. Further, a shelf 5 for placing food or the like is provided inside the refrigerator 1, and a shelf receiving portion 6 for supporting the shelf 5 is molded in the inner box 2. The inner box 2 is a hollow rectangular parallelepiped box that is open on one side, and is a foam box that is thermoformed. By using a mold having projections and depressions for molding the shelf receiving part 6 when thermoforming, the shelf receiving part 6 can also be molded at the same time, and the inner box 2 including the surface of the shelf receiving part 6 A hard layer is formed on the entire inner surface. Therefore, the inner surface of the inner box 2 has excellent aesthetics and strength.

The foam is made of a thermoplastic resin, and polyethylene, polypropylene, polystyrene, ABS resin, polyethylene terephthalate, polyacetal, polyamide and the like are used, and a closed-cell foam formed by a bead foaming method is suitable. Specifically, bead foamed polypropylene, bead foamed polyethylene, or the like is used.

In the case of this embodiment, a foam having a foaming ratio of about 5 to 30 times is used. Moreover, the force which compresses a foam at the time of manufacture of a foam changes with foam materials, the temperature of the metal mold | die of thermoforming, and a foaming ratio. In the case of 20-fold bead-foamed polyethylene and a mold temperature of 150 degrees Celsius, a press pressure of 2 kg / cm2 is required, and a foamed polyethylene with a foaming ratio of 8 times has a mold temperature of 250 degrees Celsius. In this case, a pressing pressure of 5 kg / cm 2 was necessary. This result is merely an example, and the processing conditions vary depending on the foam material used and the shape and size of the bubbles in the foam.

The outer box 3 forms the outermost shell of the refrigerator and has the role of maintaining the strength of the refrigerator 1. Here, a bent product of an iron plate is used.

The heat insulation board 4 is disposed between the inner box 2 and the outer box 3 in order to give the refrigerator 1 sufficient heat insulation properties, and foamed polyurethane is mainly adopted. In addition to the polyurethane foam, it is also possible to use a foamed polystyrene resin, a foamed phenol resin, a foamed urea resin, a vacuum heat insulating material, or the like.

Here, although the refrigerator 1 provided with the two inner boxes 2 is illustrated, not only this but the inner box 2 may be one, and may be three or more. Moreover, there is no restriction | limiting in particular in the number of the shelves 5 and the shelf receiving parts 6, and how many may be provided.

Next, a method for manufacturing a refrigerator will be described with reference to FIGS. Here, the manufacturing method of a refrigerator with one inner box 2 will be described for easy understanding.

FIG. 2 is a flowchart for explaining a method for manufacturing a heat insulating box. 3 and 4 are schematic views for explaining a method for manufacturing a heat insulating box. Hereinafter, the manufacturing method will be described with reference to the flow of FIG. In addition, S in FIG. 2 represents each step in the manufacturing method of a heat insulation box.

First, as shown in FIG. 3A, the foam 21 is temporarily assembled on the belt conveyor 100 along the fixing jig 10 made of a pipe frame (S1 in FIG. 2, the same applies hereinafter). The fixing jig 10 is composed of a hollow square pipe such as aluminum, a frame, or the like, and is assembled by being fixed by welding or a bracket. In this embodiment, since the surface of the foam 21 that forms the inner box 2 is preliminarily thermoformed with a groove as a shelf receiving part for installing a shelf board, the outer dimensions of the fixing jig 10 are as follows. Designed to be the same as the inner size of 2 when completed.

The fixing jig 10 depends on the size of the completed refrigerator and the number of partitions in the cabinet, and a plurality of types of the fixing jig 10 are required for each refrigerator model. For example, if the model has one refrigerator room and one freezer room, a fixing jig 10 corresponding to the internal dimensions of each room is required, and these fixing jigs 10 move on the belt conveyor 100. It is fixed to a pallet (not shown).

Next, as shown in FIG.3 (b), it heat-welds to the junction part 21a of the foam 21 using the hot welding tool 60, and fixes both the foam 21 (S2). As the heat welding method, vibration is applied by ultrasonic waves and the resin is melted and joined by frictional heat, or a heated metal plate is brought into direct contact with the joining surface, the melted surfaces are immediately aligned, and pressure is applied until cooling. There is a method of pressing and joining with. If necessary, if burrs are generated, they must be removed after assembly. In this embodiment, bead foam polypropylene is used as the foam 21. The melting temperature of the bead-expanded polypropylene was 140 to 160 ° C., and the foam 21 was heated with the hot welding tool 60 to reach this temperature, and was melted, adhered and fixed.

Next, as shown in FIG. 3C, piping 11 and wiring 12 necessary for the refrigerator are arranged (S3). The pipe 11 and the wiring 12 may be temporarily fixed with an acrylic adhesive or the like.

Next, as shown in FIG. 3D, an adhesive 13 is applied to the outer surface of the foam 21 including the periphery of the pipe 11 and the wiring 12 (S4). The adhesive to be used is preferably an acrylic adhesive or a hot-melt adhesive from the viewpoint of using for the purpose of storing foods, placing importance on safety.

Next, as shown in FIG. 4 (e), the heat insulating board 4 is bonded along the outside of the temporarily fixed foam 21 (S5). In this embodiment, a urethane foam board is used. It is desirable that a groove is formed in the heat insulating board 4 in advance so that the pipe 11 and the wiring 12 can be accommodated. Thus, since the foam 21 is bonded together using the fixing jig 10 to form the inner box, and the heat insulating board 4 is bonded to the outside of the inner box, the fitting accuracy is high and there is no gap. .

Next, as shown in FIG. 4 (f), the adhesive sheet 14 is temporarily fixed to the inner side of the outer box 3 (S6), and the outer box 3 is covered along the outer side to which the heat insulating board 4 is bonded (S7). . As the adhesive sheet 14, a hot melt adhesive was used. The outer box 3 is made of an iron plate having a thickness of about 1 mm, has a substantially U-shaped cross section as shown in FIG. 4 (f), and the end face is bent inward. When covering the outer box 3 on the outside of the heat insulating board 4, it is preferable that the outer box 3 is slightly warped. Or the iron plate which comprises the outer case 3 is not bend | folded, The some iron plate matched with each surface of the heat insulation board 4 may be stuck on each surface, and the method of screwing may be used.

Next, as shown in FIG. 4G, the heating member 15 is used to heat from the outside of the outer box, and the adhesive sheet 14 is heated and melted to bond the inside of the outer box 3 and the outside of the heat insulating board 4. (S8). Thus, the foam 21 is bonded together using the fixing jig 10 to form the inner box, the heat insulating board 4 is bonded to the outer side of the inner box, and the outer box 3 is bonded to the outer side of the heat insulating board 4. Since they are bonded together, the fitting accuracy is high and no gap is formed.

After that, when the hot melt adhesive is cured and the heat insulating board 4 and the outer box 3 are completely fixed, the heating member 15 and the fixing jig 10 are removed (S9), and the opening is formed as shown in FIG. The top and bottom are inverted so that they are on top (S10).

Next, another embodiment of the present invention will be described.

In the first embodiment, the surface of the foam 21 forming the inner box 2 is preliminarily thermoformed with the groove for installing the shelf board. However, in this embodiment, the foam 21 is formed before being thermoformed. It is different in using things. As in this embodiment, when the surface of the foam 21 that forms the inner box 2 is the one before thermoforming and is thermoformed in a later step, the inside of the inner box 2 is thermoformed. Each side is designed to be about 0.5 to 1 mm smaller than the inner dimension before being formed. The manufacturing method of the other heat insulation box is as having shown to the manufacturing method of the said Example 1, The inner surface of the inner box 2 is shape | molded using this.

In this embodiment, up to step 10 in FIG. 2 is performed in the same manner as in the embodiment. Thereafter, the inner surface of the inner box 2 of the refrigerator 1 is molded. In FIG. 3B, the part to be melted and bonded does not have to be the entire surface of the joint portion 21a of the foam body 21, and may be fixed in a state where the shape of the inner box 2 is temporarily maintained. In the present embodiment, both of the foams 21 are completely bonded in the hot pressing process of the inner box 2.

The molding of the inner surface of the inner box 2 of the refrigerator 1 will be described with reference to FIGS. The inner surface of the inner box 2 is molded by the molding device 31. The molding apparatus 31 includes a plurality of

molds

32a, 32b, 32c, and 32d, and a drive unit 33 that drives them and presses them against the inner surface of the inner box 2.

5A and 5B are diagrams for explaining the molding of the side surface 2a of the inner box 2, and FIG. 5A shows the inner box 2, the outer box 3, and the heat insulating board 4 before molding. An outline of the combined state viewed from the opening side of the inner box 2 is shown, and FIG. 5B shows an outline of a cross section taken along line II ′ of FIG. The side surface 2a is molded by the mold 32a. The mold 32a includes a cartridge heater (not shown) and can heat the mold 32a. In addition, a cooling oil passage is formed inside the mold 32a, and the mold 32a is cooled by circulating cooling oil inside the mold 32a by a pump (not shown). Can do. The molding apparatus 31 moves the mold 32a in the direction of the arrow 34a by the drive unit 33 and presses it against the side surface 2a. A support member (not shown) is disposed outside the outer box 3 so as to be in contact with the outer surface of the outer box 3, and is sandwiched between the outer box 3 and the heat insulating board 4 supported by the support member and the mold 32a. 2, pressure is applied.

The molding method by the molding apparatus 31 is to heat the mold 32a, press the mold 32a against the side surface 2a, defoam the foamed resin on the side surface 2a, cool the mold 32a while applying pressure, Is released and the mold 32a is removed. By cooling the mold 32a while applying pressure, a hard layer having a shape corresponding to the mold 32a can be accurately formed on the side surface 2a, and foaming of the hard layer can also be prevented.

6A and 6B are diagrams for explaining the molding of the upper surface 2b and the lower surface 2c of the inner box 2, and FIG. 6A shows the inner box 2, the outer box 3, and the heat insulation before molding. FIG. 6B shows an outline of the combined state of the boards 4 as viewed from the opening side of the inner box 2, and FIG. 6B shows an outline of a cross section taken along the line II-II ′ of FIG. ing. A support member (not shown) is disposed outside the outer box 3. The upper surface 2b is molded by the mold 32b, and the lower surface 2c is molded by the mold 32c. The molding device 31 moves the mold 32b in the direction of the arrow 34b by the drive unit 33, presses it against the upper surface 2b, and moves the mold 32c in the direction of the arrow 34c to press it against the lower surface 2c. Since the molding method of the upper surface 2b and the lower surface 2c by the molding apparatus 31 is the same as that of the side surface 2a, the description is omitted.

FIGS. 7A and 7B are views for explaining the molding of the inner surface 2d of the inner box 2, and FIG. 7A shows the inner box 2, the outer box 3, and the heat insulating board 4 before molding. 7A and 7B show an outline of the combined state seen from the opening side of the inner box 2, and FIG. 7B shows an outline of a cross section taken along the line III-III ′ of FIG. 7A. . A support member (not shown) is disposed outside the outer box 3. The back surface 2d is molded by a mold 32d. The molding apparatus 31 moves the mold 32d in the direction of the arrow 34d by the drive unit 33 and presses it against the back surface 2d. Since the molding method of the back surface 2d by the molding device 31 is the same as that of the side surface 2a, the upper surface 2b, and the lower surface 2c, description thereof is omitted.

FIG. 8 is a perspective view of the mold 32a and represents an example of the mold 32a. The inner box 2 is preferably provided with a shelf 5 on which food or the like is placed, and a side wall 2 a of the inner box 2 is preferably formed with a shelf receiving portion 6 for supporting the shelf 5. Therefore, it is preferable that the metal mold 32 a has a convex portion 35 for molding the shelf receiving portion 6. By using the mold 32a having the convex portion 35, a concave shelf receiving portion can be molded on the side surface 2a. The shape of the mold 32a is not limited thereto, and for example, the mold 32a may have a concave portion for molding a convex shelf receiving portion on the side surface 2a. The shapes of the

molds

32b, 32c, and 32d may be arbitrary shapes according to the shapes to be molded on the upper surface 2b, the lower surface 2c, and the back surface 2d, and may be flat or uneven.

As described above, the inner box 2 can be manufactured by molding the inner surface for each surface, and the inner box 2 having high strength and excellent aesthetics can be manufactured by defoaming and cooling while applying pressure. it can. At this time, the shelf receiving part 6 for supporting the shelf 5 can also be simultaneously molded by using the mold 32a having irregularities. The molding of each surface of the inner box 2 may be performed on a plurality of surfaces simultaneously, but may be performed on each surface. In addition to the molding of each surface, the boundary of each surface and the corner portion may be molded.

As described above, an inner box is formed with a foam plate based on an assembly jig formed in accordance with the inner dimension of the inner box, and a heat insulating board is bonded to the outer side of the inner box. By attaching the outer box to the outside and manufacturing the heat insulation box, it does not require a large mold, and without using complicated manufacturing equipment and manufacturing processes, the fitting accuracy at the time of assembly is high, Moreover, the heat insulating box can be molded with a high yield.

In addition, although this embodiment demonstrated the refrigerator using the heat insulation box, it can also use for not only this but an air conditioner, an air cleaner, an air conditioner.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the embodiments are also applicable. It is included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Refrigerator 2 Inner box 3 Outer box 4 Thermal insulation board 5 Shelf 6 Shelf receiving part 10 Fixing jig 11 Piping 12 Wiring 13 Adhesive 14 Adhesive sheet 15 Heating member 31

Molding apparatus

32a, 32b, 32c, 32d Mold 33 Drive part

Claims

An inner box made of foam, an outer box made of a metal plate, and a method for manufacturing a heat insulating box in which a heat insulating material is disposed between the inner box and the outer box,
An inner box forming step of arranging the foam on the basis of a fixing jig;
A heat insulating material disposing step of disposing the heat insulating material on the outside of the inner box;
The manufacturing method of the heat insulation box which performs the outer box adhesion process which adhere | attaches an outer box on the outer side of the said heat insulating material in this order.
The method for manufacturing a heat insulation box according to claim 1, wherein the fixing jig is formed according to the dimensions of the inner box.
The method for manufacturing a heat insulating box according to claim 1, wherein the inner box forming step includes a step of temporarily fixing the foams.
The method for manufacturing a heat insulating box according to claim 1, wherein the outer box bonding step includes a heating step for bonding.
After the outer box forming step,
The manufacturing method of the heat insulation box of any one of Claims 1-4 including the shaping | molding process of thermoforming the inner side of the said inner box.
A heat insulating box manufactured using the method for manufacturing a heat insulating box according to any one of claims 1 to 5.
A refrigerator manufactured using the heat insulating box according to claim 6.