JP2013174406A - Heat insulating box and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerator for stably storing an existing article that can stand by itself and a thin article, such as a bag, that is hard to stand by itself, and having a partition member that is nonobstructive when not in use.SOLUTION: A heat insulating box 1 includes an outer box 11, an inner box 12, and a heat insulating layer 13 molded by injecting, foaming and filling a foam heat insulator Lp into a space 30 inside a box 3 with the outer box 11 and the inner box 12 combined therein, and a roughened face 11s (12s) is formed on a surface of the space 30 side of at least one of the outer box 11 and the inner box 12.

Description

  The present invention relates to a heat insulating box used for a refrigerator or the like and a method for manufacturing the same.

  In recent years, in order to improve cooling performance and energy-saving performance in a refrigerator equipped with a storage room for storing articles at a low temperature such as a refrigeration room and / or a freezer room, foam insulation such as urethane foam or vacuum insulation with high heat insulation performance Is used. Although the said vacuum heat insulating material is excellent in heat insulation performance, it is inferior in strength compared with foam heat insulating materials, such as urethane foam. Therefore, in order to maintain sufficient strength in the heat insulating box using the vacuum heat insulating material, a strong foam heat insulating material is filled in the periphery of the vacuum heat insulating material and the region in the thickness direction. That is, even when the vacuum heat insulating material is used, a foam heat insulating material is used to satisfy the structural strength and the heat insulating performance as the heat insulating box of the refrigerator.

  A conventional refrigerator manufacturing method is performed as follows. An outer box and an inner box are combined to produce a box body having a space between the outer box and the inner box. Then, refrigeration cycle parts, electrical parts, other mechanical parts, etc. are attached to the space. At this time, the box body is assembled only by fitting the peripheral portion of the outer box and the inner box, and the wall surface portion is easily bent (is easily deformed). For this reason, an outer box and an inner box with mechanical parts and the like attached inside are attached to a foaming jig to suppress deformation.

  And the heat insulation box which has intensity | strength is produced by inject | pouring the stock solution of a foam heat insulating material inside the space of the said box attached to the said foaming jig, and making it foam-harden. As described above, the cured foam heat insulating material not only functions as a heat insulating member but also functions as a structural member. In general, in the case of rigid polyurethane foam often used as a heat insulating material, it has a property of strongly adhering to an outer box and an inner box to further increase its structural strength.

  When the foam insulation material foams, a high pressure (foaming pressure) acts on the outer box and the inner box. In order to suppress swelling due to foaming pressure applied to the outer box and the inner box, the foaming jig has a strong structure capable of withstanding the foaming pressure. For example, each foaming jig is made of heavy steel or the like. The foaming jig includes an outer jig and an inner jig, the outer jig is disposed outside the inner jig, and foamed in a space between the outer jig and the inner jig. The box before injecting the heat insulating material is attached. The box is arranged, and a foam heat insulating material is injected from an inlet provided in the box. The injected foam insulation is foamed inside the foaming jig (that is, the space). In order to promote the foaming reaction and the curing reaction of the foamed heat insulating material, the heat insulating box is manufactured by arranging each foaming jig inside a heating furnace adjusted to a predetermined temperature for a predetermined time.

  In the manufacturing process of the heat insulation box, the completed heat insulation box is removed from the foaming jig. Then, another box is mounted on the foaming jig, and the foam heat insulating material is injected again to manufacture the next heat insulating box (continuous manufacturing). In such a manufacturing process, the foaming jig is heated by reaction heat generated during foaming of the foam heat insulating material and heating for promoting hardening of the foamed heat insulating material filled in the heating furnace. Thereby, the temperature of the foaming jig tends to increase as the number of manufactured heat insulating boxes increases. Among the foaming jigs, the outer jig has many surfaces exposed to the outside air, so the temperature rise is relatively moderate, but the inner jig takes out the heat insulating box, and the next heat insulating box is Since only a short time until attachment is exposed to the outside air, hot air stays in the concave portion of the inner jig, and the temperature of the inner jig rises.

  When the temperature of the foaming jig rises, the temperature of the foam heat insulating material injected into the box also rises, the viscosity of the foam heat insulating material decreases, and the fluidity increases. When the foam heat insulating material has high fluidity, the cell structure of closed cells in the foam becomes elliptical in the flow direction of the foam heat insulating material. When the cell structure of the closed cell becomes elliptical, the compressive strength necessary for obtaining the structural strength cannot be obtained, and depending on the shape of the closed cell, the heat insulating performance is also lowered. Furthermore, when the viscosity of the foam heat insulating material is low, the foam heat insulating material may leak from the gap between the fitting portions of the outer box and the inner box, and the heat insulating box body cannot be removed from the jig. Troubles and heat insulation boxes may result in product defects that cannot be repaired.

  A method for suppressing the temperature rise of the inner jig that causes such troubles and product defects has been proposed. Japanese Patent Application Laid-Open No. 63-180070 proposes that a large number of holes are provided in the inner jig of the foaming jig and a fan is provided on the inner upper portion of the inner jig. Japanese Patent Application Laid-Open No. 2004-92958 discloses controlling the temperature of a foaming jig by arranging a plurality of temperature adjusting units that hold a flow path for hot water inside and outside the outer jig. Then, it has been proposed to inject a foam heat insulating material to form a heat insulating box. Furthermore, in Japanese Patent Application Laid-Open No. 2008-157521, the inner jig of the foaming jig is heated with hot air by a hot air generator, so that the heat heated from the inside is moved from the inner jig to the outer jig, and foaming is performed. It has been proposed to warm the entire jig to make the temperature uniform.

Japanese Unexamined Patent Publication No. 63-180070 JP 2004-92958 A JP 2008-157521 A

However, in the case of an internal jig having a structure in which a large number of holes are provided and a fan is attached as in JP-A-63-180070, the cost of the internal jig itself increases. In addition, although the inner jig itself is easily cooled, the heat easily escapes, so that the heat easily escapes even in the foaming process of the foam insulation. ) Temperature control becomes difficult.

Moreover, manufacture of a heat insulation box is performed on the manufacturing line which flows sequentially in a horizontal direction. That is, the foaming jig is also configured to move in the horizontal direction. As shown in Japanese Patent Laid-Open No. Sho 63-180070, wiring is arranged on a fan attached to the inner jig, or Japanese Patent Laid-Open Publication No. 2004-92958 is published. It is difficult to arrange wiring and piping in a temperature control unit attached to a jig such as this, and it is difficult to operate the fan and the temperature control unit.

  Furthermore, as in Japanese Patent Application Laid-Open No. 2008-157521, even in a configuration in which hot air is blown onto the foaming jig, the device for generating hot air must be moved in accordance with the movement of the heat insulating box. Installation of equipment for heating is difficult.

  Therefore, the present invention solves the above-described problems, and can improve the yield without using a special device or process, and has a heat insulation box having high heat insulation and structural strength, and a method for manufacturing the same. The purpose is to provide.

  In order to achieve the above object, the present invention injects foam insulation into a space between an outer box, an inner box, and a box body that is a combination of the outer box and the inner box, and forms by foaming and filling. There is provided a heat insulating box comprising a heat insulating layer, and a rough surface formed on a surface of at least one of the outer box and the inner box on the space side.

  According to this structure, even if a foaming heat insulating material is heated and a viscosity falls, the fluidity | liquidity of a foaming heat insulating material is suppressed by friction with the part in which the rough surface is formed. Thereby, since a foaming heat insulating material flows uniformly in the said space, the distortion of the said heat insulation layer, a nonuniformity, etc. can be suppressed.

  Thereby, the heat insulation performance of a heat insulation box can be improved. Moreover, in the said heat insulation box, since the heat insulation layer is utilized also as a structural strength member, it is possible for a heat insulation box to have the intensity | strength determined beforehand. Moreover, from this, it is also possible to increase the yield at the time of molding the heat insulating layer.

  The said structure WHEREIN: The fitting part fitted when the said outer box and the said inner box are combined is each provided, The vicinity of the said fitting part may be sufficient as the part which forms the said rough surface. According to this configuration, even when the viscosity of the foam heat insulating material is lowered, it is possible to suppress the foam heat insulating material from flowing out of the box body by the frictional force between the rough surface formed in the vicinity of the fitting portion. it can. Thereby, the yield at the time of manufacture of a heat insulation box can be raised.

  In the above configuration, the outer box is formed with air holes for removing gas generated when the foam heat insulating material foams and air remaining in the space, and the portion forming the rough surface is It may be near the air vent of the outer box. According to this structure, the flow rate of the foam heat insulating material can be suppressed in the vicinity of the air hole, and gas, air, and the like can be extracted firmly. Thereby, it can suppress that defects, such as a space, generate | occur | produce in the said heat insulation layer.

  The said structure WHEREIN: When the part which forms the said rough surface is arrange | positioned with the front side of the said box facing down, the vicinity of the part which forms the lower part of the said space of the said inner box may be sufficient.

  In order to achieve the above object, the present invention includes a step of bending a flat plate to form at least a part of an outer box, and a step of injecting a foam heat insulating material into a space between a box body in which the outer box and the inner box are combined. And a step of foaming the foam heat insulating material, and before the step of forming the outer box, a method of manufacturing a heat insulating box having a step of roughening the surface of the flat plate is provided. .

  According to this configuration, since the rough surface is formed before the complicated bent portion is formed in order to suppress the leakage of the foamed heat insulating material, the rough surface can be easily formed.

  According to the present invention, it is possible to provide a heat insulating box having high heat insulating properties and structural strength, and a method for manufacturing the same, while improving the yield without using a special device or process.

It is sectional drawing of a refrigerator. It is sectional drawing of the heat insulation box concerning this invention. It is a perspective view which shows the jig | tool used for shaping | molding of the heat insulation box concerning this invention. It is the IV-IV sectional view taken on the jig shown in FIG. It is sectional drawing which shows the state which has inject | poured the foam heat insulating material into the box. It is sectional drawing which calls the state which a foaming heat insulating material is foaming. It is an expanded sectional view of the part which the outer box and inner box of the heat insulation box concerning this invention fit. It is a figure which shows the metal plate before formation of an outer case. It is a figure which shows having formed the rough surface in the metal plate of FIG. 8A. It is a figure which shows that the metal plate of FIG. 8B was bent and the fitting part was formed. It is a figure which shows the state which bent the metal plate shown to FIG. 8C in U shape. It is a perspective view of an inner box. It is a figure which shows that the rough surface is formed in the inner box shown to FIG. 8E. It is a figure which shows the state which attached the inner box of FIG. 8F to the U-shaped metal plate of FIG. 8C. It is a figure which shows the state which attached the baseplate. It is a figure which shows having attached the backplate and inject | pouring the foam heat insulating material. It is an expanded sectional view around the air hole in the outer box and inner box of the heat insulation box in the present invention.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of the refrigerator. In the cooler shown in FIG. 1, illustrations of refrigeration cycle components such as an evaporator and a compressor, and electrical components such as a control board are omitted.

  As shown in FIG. 1, the refrigerator Rf includes a heat insulating box 1 according to the present invention and a door Dr attached to the front of the heat insulating box 1 so as to be opened and closed. The heat insulation box 1 has a concave space (concave portion) in which two independent front sides are opened up and down. The upper space R1 is a refrigeration chamber for storing articles at a lower temperature than the outside, and the lower space R2 is a freezing chamber for storing articles in a frozen state. The door Dr is attached to the front of the upper space R1 and the lower space R2 so as to be opened and closed independently.

  The heat insulation box 1 is demonstrated with reference to drawings. FIG. 2 is a sectional view of the heat insulation box according to the present invention. As shown in FIG. 2, the heat insulating box 1 includes an outer box 11, an inner box 12 disposed inside the outer box 11, and a heat insulating layer 13 disposed between the outer box 11 and the inner box 12. It has. In the following description, a combination of the outer box 11 and the inner box 12 and not including the heat insulating layer 13 is referred to as a box 3.

  The outer box 11 is formed by bending a steel plate having a thickness of about 1 mm into a box. The outer box 11 has a box shape whose front side is open. The inner box 12 is attached to the opening of the outer box 11. When attached to the outer box 11, the inner box 12 has a so-called dome-shaped first recess 121 and second recess 122 when viewed from the outside. Yes. In addition, when manufacture of the heat insulation box 1 is completed, the 1st recessed part 121 is a part used as the upper stage space R1, and the 2nd recessed part 122 becomes the lower stage space R2. Since the inner box 12 mainly includes a portion that becomes the upper space R1 for storing food and a portion that becomes a wall surrounding the lower space R2, the inner box 12 is manufactured by vacuum molding of a resin such as ABS, PP, and PS. In the present embodiment, the inner box 12 is formed so that the ABS resin has a thickness of about 1 mm. Although not described in detail, the door Dr also has a structure in which a heat insulating layer is arranged between an inner box and an outer box of a box body that is a combination of an inner box and an outer box.

  The heat insulating layer 13 is a heat insulating member that suppresses the movement of heat between the outside and the inside of the heat insulating box 1 and is also a strength member for maintaining the structural strength of the heat insulating box 1. The heat insulating layer 13 is made of polyurethane foam. In addition to the polyurethane foam, it is also possible to employ a foamed styrene resin, a foamed phenol resin, a foamed urea resin, or the like. The heat insulating layer 13 is formed by injecting a raw solution of foam heat insulating material into a space formed when the outer box 11 and the inner box 12 are combined to form a box, and foam filling inside the space. .

  For molding the heat insulating layer 13 (foamed polyurethane), a stock solution in which cyclopentane is added as a foaming agent to a mixed solution of polyol and isocyanate is used. And the heat insulation layer 13 is formed by inject | pouring this stock solution into the space formed by the outer box 11 and the inner box 12, and producing a foaming reaction (dehydration reaction). This foaming reaction generates heat and foams in a narrow space. And in order for the heat insulation layer 13 to obtain the heat insulation performance and structural strength requested | required by the heat insulation box 1, the foaming polyurethane undiluted | stock solution so that the foaming pressure in space may be about 0.1-1.0 kg / cm <2>. The blending ratio, filling pressure, temperature, injection amount, etc. are controlled.

  Although the foaming pressure itself is not so high, in the case of a large refrigerator of about 500 mm × 500 mm × 2000 mm, the total pressure acting on each surface of the outer box 11 and the inner box 12 may reach 10 t. As described above, the outer box 11 is a thin molded body of a steel plate, and the inner box 12 is a molded body of a thin resin, and it is difficult to face such a large force. Therefore, when manufacturing the heat insulation box 1, the jig 2 is used to counter the foaming pressure.

  Next, the metal mold | die used for manufacture of the heat insulation box 1 is demonstrated with reference to drawings. FIG. 3 is a perspective view showing a jig used for forming the heat insulating box according to the present invention, and FIG. 4 is a sectional view taken along line IV-IV of the jig shown in FIG.

  As shown in FIGS. 3 and 4, the jig 2 is attached to the outer jig 21 so as to be openable and closable with the outer jig 21 arranged in contact with the side surface and the upper and lower surfaces of the outer box 11. An upper lid 22 arranged in contact with the back side and an inner jig 23 arranged in contact with the inner surface of the inner box 12 are provided. The jig 2 can be fitted with the box 3 in a state in which the side surface of the outer jig 21 and the upper lid 22 are unfolded. After the urethane foam is foamed and cured, the formed heat insulating box 1 can be easily attached to the jig 2. It can be removed from the mold.

  The outer jig 21 covers the upper and lower surfaces and both side surfaces of the heat insulating box 1 (or box 3). The upper lid 22 is a flat member and is attached to one end surface of the outer jig 21 so as to be opened and closed. The inner jig 23 is arranged inside the outer jig 21 and includes convex portions 231 and 232 that engage with the two concave portions 121 and 122 of the inner box 12, respectively. The convex portions 231 and 232 are arranged inside a space formed by the outer jig 21 and the upper lid 22, and have a concave shape on the opposite side to the inner box 12.

  The outer jig 21, the upper lid 22 and the inner jig 23 are made of thick metal such as iron or aluminum in order to suppress distortion and deformation of the outer box 11 and the inner box 12 even when the pressure as described above is applied. It is made of a plate material.

  As described above, the upper lid 22 is used as a jig for suppressing deformation and distortion of the outer box 11 and also as a door for taking out the heat insulating box 1 after the formation of the heat insulating layer 13 is completed. Used. That is, the upper lid 22 is closed until the molding of the heat insulating layer 13 is completed. When the molding of the heat insulating layer 13 is completed, the jig 2 can take out the heat insulating box 1 to the outside of the mold by opening the upper lid 22. An injection port 110 for injecting a foamed polyurethane stock solution is formed on the back surface of the outer box 11. An opening 220 for injecting a foamed polyurethane stock solution is also formed in the upper lid 22.

  Next, the manufacturing method of a heat insulation box is demonstrated with reference to drawings. FIG. 5 is a cross-sectional view showing a state where the foam heat insulating material is injected into the box, and FIG. 6 is a cross-sectional view showing a state where the foam heat insulating material is foamed. As shown in FIG. 5, the outer jig 21 of the jig 2 is in contact with the side surface and the upper and lower surfaces of the outer box 11, and the upper lid 22 is in contact with the back surface of the outer box 11. The inner jig 22 is in contact with the inner box 12. The outer box 11 and the inner box 12 constitute a box 3, and a space 30 is formed in the box 3 between the outer box 11 and the inner box 12.

  The injection head Ih is inserted into the back side of the outer box 11 so as to pass through the injection port 110 and the opening 220 of the upper lid 22, and a stock solution of foamed polyurethane Lp is injected into the space 30 by the injection head Ih. After the injection, the injection head Ih is quickly pulled out, and the entire space 30 is foamed in a sealed state so that the foamed polyurethane Lp22 does not leak from the injection port 110 of the outer box 11. The foaming reaction of the foamed polyurethane Lp proceeds from the surface close to the bottom, and the entire filling ends at the upper part of the jig 2 while flowing upward on the side surface (see FIG. 6).

  At this time, the jig 2 is placed in a heating furnace (not shown) to promote the curing reaction of the polyurethane foam. Here, the jig temperature is ideally heated to 40 to 50 ° C. For a while while the foam curing progresses, the jig 2 continues to be subjected to a high foaming pressure, and when the foaming pressure is settled and the dimensions are generally stabilized, the box 3 is taken out of the jig 2 and the heat insulating box 1 Complete.

  In the heat insulation box 1 of the present invention, the rough surface 12s is formed on the bottom surface and the side surface of the inner box 12 on the space 30 side, and the temperature of the inner jig 23 rises during continuous production, so that the viscosity of the polyurethane foam is increased. Even if the surface is lowered, the friction is greater on the surface with the rough surface 12s than on the other surface. Thereby, the fluidity | liquidity of foaming polyurethane is reduced and it becomes possible to obtain the heat insulation layer 13 uniform in the heat insulation box 1 whole.

  Since the space 30 side of the inner box 12 is a rough surface, the fluidity of the polyurethane foam accompanying the temperature rise of the inner jig 23 can be reduced, and the closed cells of the heat insulating layer 13 after being cured are spherical. can do. Thereby, the heat insulation layer 13 which does not impair both heat insulation performance and compressive strength can be formed. In general, foamed thermal insulation foams increase in viscosity as it flows after the start of the reaction, so the longer the flow distance, the smaller the surface roughness and the more uniform performance throughout the thermal insulation box. The foam can be obtained. Further, by suppressing the fluidity of the polyurethane foam, it is possible to suppress the polyurethane foam from flowing out from the space between the outer box 11 and the inner box 12.

  In the heat insulation box 1, the bottom surface and the side surface of the inner box 12 on the space 30 side are rough surfaces 12s, but the present invention is not limited to this, and other surfaces may be roughened. For example, as shown in FIG. 7, the space 30 side surface around the fitting part 111 of the outer box 11 and the fitting part 123 of the inner box 12 may be roughened. FIG. 7 is an enlarged cross-sectional view of a portion where the outer box and the inner box of the heat insulating box according to the present invention are fitted.

  Generally, when the temperature of the inner jig 23 in the jig 2 exceeds 40 ° C. to 50 ° C. which is an appropriate temperature, the viscosity of the polyurethane foam is lowered, and the fitting portion 111 of the outer box 11 and the inner box 12 The fitting portion 123 tends to cause the polyurethane foam to leak.

  Then, like the heat insulation box 1 shown in FIG. 7, the surface of the fitting part 111 of the outer box 11 and the fitting part 123 of the inner box 12 is formed in the rough surfaces 11s and 12s, whereby the foamed polyurethane Lp stock solution is formed. After the injection, while the heat insulating layer 13 is formed through cream time (CT) and gel time (GT), resistance acts on the polyurethane foam and the surface of the rough surface portion to increase the frictional force. This makes it difficult for the polyurethane foam to flow in the vicinity of the fitting portion 111 of the outer box 11 and the fitting portion 123 of the inner box 12, and as a result, leakage of the polyurethane foam can be suppressed.

  Next, the manufacturing process of a heat insulation box is demonstrated with reference to drawings. 8A to 8I are diagrams showing an outline of each process in the manufacturing process of the heat insulating box according to the present invention. As shown in FIG. 8A, a rectangular metal flat plate Mp is prepared. The metal flat plate Mp has a surface coated and is a raw material that becomes the top plate and the side plate of the outer box 11.

  As shown in FIG. 7, the rough surface of the outer box 11 is formed in the fitting part 111 of the outer box 11 bent in a complicated manner, and it is difficult to form the rough surface after the bending. Therefore, as shown in FIG. 8B, a portion to be the fitting portion 111 of the long side outer box 11 of the metal flat plate Mp is polished with the abrasive Fm1 to form a rough surface. The fitting portion 111 also includes a portion that becomes a front portion of the heat insulating box 1. Therefore, it is preferable that the end face portion of the outer box 11 which is roughened is provided on both the inner side and the outer side except for the surface of the front surface portion.

  Then, as shown in FIG. 8C, the fitting portion 111 is formed by bending the long side of the metal flat plate Mp. As shown in FIG. 7, the fitting portion 111 has a structure in which the foamed polyurethane is folded in multiples so that the foamed polyurethane does not leak out during the foaming reaction. Then, as shown in FIG. 8D, a rectangular metal flat plate Mp is bent into a U-shape to form a top plate 115 and both side plates 116. In addition, refrigerant pipes and the like are arranged in advance inside the top plate 115 and the side plates 116 (before injecting the polyurethane foam).

  And the inner box 12 as shown to FIG. 8E is manufactured by resin vacuum forming. As shown in FIG. 8F, the first recess 121 of the inner box 12, the surface of the second recess 122 on the space 30 side, and the fitting portion 123 are processed into a rough surface with an abrasive Fm2.

  Examples of the abrasives Fm1 and Fm2 include a file and a sand blaster. Moreover, the grindstone particle size is changed and the surface roughness of the outer box 11 and the inner box 12 is changed. In the present embodiment, a grindstone having a particle size of about 150 to 1000 μm is used. The surface roughness at this time is preferably 10 μm or more, and the rough surface should have a rough surface with no gloss.

  As shown in FIG. 8G, the inner box 12 is combined with a U-shaped metal plate (a part of the outer box 11) having a top plate 115 and both side plates 116. At this time, the fitting portion 111 of the outer box 11 and the fitting portion 123 of the inner box 12 are fitted (see FIG. 7). As shown in FIG. 8H, the bottom plate 112 is attached. Then, as shown in FIG. 8I, the box 3 is formed by attaching the rear plate 113.

  As shown in FIG. 8I, after the combined outer box 11 and inner box 12 are arranged in a jig so that the rear plate 113 becomes the top surface (see FIG. 5), in the space 30 of the formed box 3, An injection head Ih is inserted from the injection port 110 to inject a foamed polyurethane stock solution. Two or four inlets 110 are prepared depending on the size of the box 3. Further, the rear plate 113 is preliminarily provided with air holes so that air in the space 30 is released to the outside when the foaming reaction of the polyurethane foam proceeds. As the position of the air hole 114, it is preferable that the polyurethane foam injected from the plurality of injection heads Ih is provided at a joining portion where the heat insulating layer 13 is formed in the space 30. The bottom plate 112 may also have air holes.

  The manufacturing method of the other example of the heat insulation box concerning this invention is demonstrated with reference to drawings. FIG. 9 is an enlarged cross-sectional view around the air holes in the outer box and the inner box of the heat insulating box according to the present invention. As shown in FIG. 9, the outer box 11 of the heat insulating box 1 is roughened on the surface on the space 30 side around the air holes 114. A plurality of air holes 114 are provided on a line (weld line) where polyurethane foam injected from a plurality of injection heads Ih merges.

  The reaction gas and the remaining air in the space 30 are discharged from the air hole 114. A hole having a diameter of about 0.5 to 1 mm is formed as the air hole 114. At this time, the weld line is virtually located in the central portion of the box 3, but the weld line is not necessarily located in the central portion depending on the amount of injection from the injection head Ih and the flow of foamed polyurethane. There are times when it shifts. At this time, voids (nests) are likely to be generated in the heat insulating layer 13 on the weld line. Also, in the portion of the inner box 12 that is located opposite to the outer box 11 provided with the air holes 114, when the foamed polyurethane foams, it is more likely that the center position reaches the weld line than near the wall surface. Since it is fast, the curing reaction takes place first at the center position, and voids (nests) are likely to occur in the foam on the inner box 6 side.

  In this embodiment, the periphery of the air hole 114 is roughened, and by delaying the flow of the polyurethane foam around the air hole 114, the foaming locus a1, the foaming locus b1, and the foaming locus c1 as shown by the wavy lines in FIG. Thus, the heat insulating layer 13 is formed. As a result, it becomes easy to secure an air escape path, and generation of voids (nests) can be suppressed, and the heat insulating layer 13 having uniform performance can be obtained even on the weld line.

  By forming the heat insulation box as described above, it is possible to suppress the heat insulation layer of the heat insulation box from being distorted or biased. Thereby, while being able to improve heat insulation, it is possible to raise structural strength. Moreover, since it suppresses that a foaming heat insulating material leaks outside the box, it suppresses that the yield of a heat insulation box falls.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this content. The embodiments of the present invention can be variously modified without departing from the spirit of the invention.

  According to the heat insulation box according to the present invention, the finished dimensional accuracy can be increased, and the efficiency of adjustment work in the post-assembly process such as weight reduction of heavy jigs and door attachment can be improved.

A Molding apparatus 1 Heat insulation box 11 Outer box 12 Inner box 2 Mold 21 Outer mold 22 Mold door 23 Inner mold 3 Box 30 Space

Claims (5)

An outer box, an inner box,
Injecting foam heat insulating material into the space between the outer box and the inner box combined with the inner box, and comprising a heat insulating layer foamed, filled and molded,
A heat insulating box characterized in that a rough surface is formed on a surface of at least one of the outer box and the inner box on the space side. The outer box and the inner box each have a fitting portion to be fitted when combined,
The heat insulating box according to claim 1, wherein a portion forming the rough surface is in the vicinity of the fitting portion. The outer box is formed with air holes for extracting gas remaining when the foam heat insulating material foams and air remaining in the space,
The heat insulation box according to claim 1 or 2, wherein the portion forming the rough surface is near the air vent of the outer box.   The portion that forms the rough surface is in the vicinity of a portion that forms the lower portion of the space of the inner box when the front side of the box is placed downward. The heat insulation box as described in. Bending at least one part of the outer box by bending a flat plate;
Injecting foam insulation into the space between the box that combines the outer box and the inner box;
And foaming the foam insulation.
Before the process of forming the said outer box, it has the process of roughening the surface of the said flat plate, The manufacturing method of the heat insulation box characterized by the above-mentioned.

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