Heat insulating door and refrigerator having same

Abstract

The present invention is provided with: an outer plate (51); a reinforcing plate (57) provided on the rear surface side of the outer plate (51); and a hot melt adhesive material (58) for bonding the outer plate (51) and the reinforcing plate (57). A foamed heat insulation material (55) foamed on site is provided in a space facing the rear surface of the outer plate (51). The outer plate (51) is a material that can be deformed by the pressure of on-site foaming of the foamed heat insulation material (55). The hot melt adhesive material (58) is applied to the outer periphery of the reinforcing plate (57) between the rear surface of the outer plate (51) and the reinforcing plate (57).

Description

Insulated door and refrigerator equipped with same

[0001] The present invention relates to a heat-insulating door and a refrigerator equipped with the same.

[0002] Insulated doors used in refrigerators are known to deform due to the shrinkage force of the foam insulation when vacuum insulation or the like is fixed to the backside of the outer panel of a steel or resin door and foam insulation is then filled inside the door. This is because the shrinkage force is applied differently at the boundary of the vacuum insulation, leaving marks along the boundary on the surface of the outer panel. For this reason, a reinforcing plate is installed between the outer panel and the vacuum insulation.

[0003] However, when foam insulation is filled into the door on the back surface of the outer panel, if a gap is formed between the outer panel and the reinforcing plate, the foam insulation will get into the gap and deform the outer panel. Therefore, in Patent Document 1, the reinforcing plate is fixed to the back surface of the outer panel with adhesive tape to prevent the formation of a gap between the outer panel and the reinforcing plate.

[0004] JP 2023-44834 A

[0005] However, as described in Patent Document 1, although the use of adhesive tape prevents the formation of a gap between the outer panel and the reinforcing panel, there is a problem that it is difficult to automate the work.

[0006] The insulated door of the present invention comprises an outer panel, an intervening member provided on the back side of the outer panel, and an adhesive that is fluid when applied and bonds the outer panel and the intervening member.

[0007] FIG. 1 is a front view of a refrigerator according to a first embodiment. FIG. 2 is a front perspective view of an insulated door of a lower freezer compartment. FIG. 3 is an exploded perspective view of the insulated door of FIG. 2. FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 2. FIG. 5 is an enlarged view of a main part of FIG. 4. FIG. 6 is a table showing the presence or absence of urethane penetration based on the thickness of a hot melt adhesive. FIG. 7 is a front view of an insulated door to which a hot melt adhesive has been applied. FIG. 8 is a front view of an insulated door of a second embodiment. FIG. 9 is a front view of an insulated door of a third embodiment. FIG. 10 is a cross-sectional view of an insulated door of a fourth embodiment.

[0008] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the following embodiment. First, the overall configuration of a refrigerator 1 according to this embodiment will be described.

[0009] FIG. 1 is a front view of a refrigerator 1 according to a first embodiment. As shown in FIG. 1, the refrigerator 1 includes storage compartments, arranged in the following order from top to bottom: a refrigerator compartment 2, an ice-making compartment 3, an upper freezer compartment 4, a lower freezer compartment 5, and a vegetable compartment 6. The insulated doors 2a and 2b that open and close the refrigerator compartment 2 are pivotable, rotating around hinges (not shown). The insulated door 3a that opens and closes the ice-making compartment 3, the insulated door 4a that opens and closes the upper freezer compartment 4, the insulated door 5a that opens and closes the lower freezer compartment 5, and the insulated door 6a that opens and closes the vegetable compartment 6 are all drawer-type doors. The insulated doors 2a and 2b of the refrigerator compartment 2 are not limited to double-doors (French doors) and may be single doors. The arrangement and number of the storage compartments and their insulated doors are not limited to those shown in FIG. 1 .

[0010] The insulated box of the refrigerator 1, not shown, comprises a steel outer box and a resin inner box. The space formed by the outer and inner boxes is filled with foam insulation materials such as rigid urethane foam and vacuum insulation materials using glass wool, etc., to insulate each storage compartment from the outside. The following describes the structure of the insulated door of the refrigerator 1. Types of insulation materials include fiber-based insulation materials (glass wool, rock wool, cellulose fiber, etc.) and foam-based insulation materials (urethane foam, phenolic foam, etc.). Among foam-based insulation materials, urethane foam (rigid urethane foam) is often used as a foam insulation material that is foamed on-site. Urethane is a compound with a urethane bond formed by the reaction of a polyol component and an isocyanate component.

[0011] To explain the configuration of the insulated door of the refrigerator 1, first, a drawer-type insulated door will be described, taking the insulated door 5a of the lower freezer compartment 5 as a representative example. Fig. 2 is a front perspective view of the insulated door of the lower freezer compartment, Fig. 3 is an exploded perspective view of the insulated door of Fig. 2, and Fig. 4 is a cross-sectional view taken along line IV-IV of Fig. 2. As shown in Figs. 2 to 4, the insulated door 5a includes an outer panel 51 provided on the front side (front side) to form a design surface, door frames provided on the upper and lower edges of the outer panel 51, an inner panel 54 (liner) provided on the back side (rear side) of the outer panel 51, and foam insulation 55 foamed in situ in a space Y surrounded by the outer panel 51, the door frame, and the inner panel 54. In addition to the foam insulation 55, a vacuum insulation panel 56 is provided in the space Y so as to face the outer panel 51, and a reinforcing plate 57 (intervening member) is provided between the outer panel 51 and the vacuum insulation panel 56. The details of the reinforcing plate 57 will be described later. In most cases, foaming on site is performed (construction) on-site at a manufacturing factory for refrigerators (insulated doors).

[0012] The outer panel 51 is made of a material that can be deformed by the pressure of the in-situ foaming of the foam insulation 55, and is formed of, for example, a thin steel plate. The outer panel 51 is also bent backward (rearward) at left and right curved portions 511.

[0013] The door frame is made of resin, and as shown in Figure 3, has an upper frame portion 52 attached to the upper edge of the outer panel 51 and a lower frame portion 53 attached to the lower edge of the outer panel 51. The upper frame portion 52 is formed with a handle portion 521 on which the user places their hand when opening or closing the door.

[0014] The vacuum insulation material 56 is, for example, a core material such as glass wool sealed with a laminate film having gas barrier properties to reduce the pressure inside. Furthermore, the insulation material is not limited to the vacuum insulation material 56, and may be, for example, a plate-shaped insulation material in which a core material (pre-foamed foam insulation material) made of foam insulation material such as rigid urethane foam molded into a flat plate is covered and sealed with a laminate film having gas barrier properties. Among the insulation materials used in refrigerators, the vacuum insulation material 56 and plate-shaped insulation materials do not fall under the category of foam insulation material foamed in situ.

[0015] The inner plate 54 is formed by injection molding a resin such as polypropylene, and is fixed to the backsides of the left and right bent portions of the outer plate 51 and the backsides of the upper frame portion 52 and the lower frame portion 53 to form a space Y inside the insulated door 5a, as shown in Figure 4. Recesses 542 are formed on the edge of the inner plate 54 so as to surround the four sides (top, bottom, left, and right), and a gasket (not shown) is attached to this recess 542. Therefore, when the insulated door 5a is closed, the gasket comes into contact with the front opening of the lower freezer compartment 5, sealing the lower freezer compartment 5.

[0016] After the foam insulation 55 is filled, the foam insulation 55 thermally shrinks, pulling the outer panel 51 via the vacuum insulation 56. Therefore, if the vacuum insulation 56 were directly attached to the steel outer panel 51, the unevenness on the surface of the vacuum insulation 56 or the edges of the vacuum insulation 56 could leave marks on the surface of the outer panel 51, potentially resulting in poor appearance. Therefore, in this embodiment, as shown in FIG. 4 , a reinforcing plate 57 is disposed between the outer panel 51 and the vacuum insulation 56. The material of the reinforcing plate 57 can be the same as that of the outer panel 51 (steel plate in this embodiment). The use of the reinforcing plate 57 substantially increases the thickness of the outer panel 51, improving the strength of the outer panel 51. This makes the outer panel 51 less likely to deform even when pulled due to the thermal shrinkage of the foam insulation 55, and thus reduces the likelihood of marks due to distortion appearing on the surface of the outer panel 51. Such marks can appear not only when the outer panel 51 is made of steel plate, but also when the intervening member is made of resin. This problem may also occur when the outer panel 51 is made of glass as an intervening member.

[0017] Figure 5 is an enlarged view of a main portion of Figure 4. As shown in Figure 5, the reinforcing plate 57 is placed opposite the rear surface of the outer panel 51, and a hot-melt adhesive 58 (an adhesive that is fluid when applied) is applied between the rear surface of the outer panel 51 and the reinforcing plate 57, thereby adhering and fixing the reinforcing plate 57 to the outer panel 51. The hot-melt adhesive 58 (adhesive) is solid at room temperature and is heated and melted to become fluid when applied. After application, the hot-melt adhesive 58 is left in a room-temperature environment and cooled, whereby the hot-melt adhesive 58 solidifies and fixes the reinforcing plate 57 to the outer panel 51. For example, a polyamide-based hot-melt adhesive 58 is used. Whether the adhesive is "fluid when applied" (whether it is hot-melt adhesive) can be easily determined after the fact by analyzing the adhesive used.

[0018] The hot melt adhesive 58 is formed up to the edge 57a (edge ​​of the interposed member) of the reinforcing plate 57. This prevents the foam insulation material 55 (urethane) from entering the gap between the outer plate 51 and the reinforcing plate 57.

[0019] FIG. 6 is a table showing the presence or absence of urethane infiltration based on the thickness of the hot melt adhesive. When a reinforcing plate 57 is fixed to an outer panel 51 using hot melt adhesive 58, a gap is formed between the outer panel 51 and the reinforcing plate 57. If this gap is large, foam insulation 55 (urethane) may infiltrate into the gap, potentially causing poor appearance of the outer panel 51. Therefore, when fixing the outer panel 51 and the reinforcing plate 57 with hot melt adhesive 58, we investigated the presence or absence of urethane infiltration when varying the thickness T of the hot melt adhesive 58 in its solidified state. As shown in FIG. 6 , urethane infiltration was confirmed when the thickness T of the hot melt in its solidified state was set to 0.16 mm, and also when the thickness T was set to 0.12 mm. Furthermore, no urethane infiltration was confirmed when the thickness T of the hot melt in its solidified state was set to 0.09 mm. In this way, it was confirmed that by setting the thickness T of the hot melt adhesive 58 in its solidified state to 0.1 mm or less, it is possible to prevent the hot melt adhesive 58 from penetrating into the gap between the outer panel 51 and the reinforcing plate 57.

[0020] Furthermore, a coating device equipped with a spiral-type nozzle can be used to apply the hot melt adhesive 58. The spiral type applies the hot melt adhesive 58 while rotating it in a spiral shape. By using such a spiral type, coating can be performed with less thickness unevenness than with a normal nozzle type or mist type. Furthermore, by using the spiral type, a coating thickness of approximately 0.1 mm can be achieved, which is thinner than with a normal nozzle type or mist type. In other words, if the coating thickness of the hot melt adhesive 58 can be approximately 0.1 mm during application, the thickness T in the solidified state can be reduced to 0.1 mm or less.

[0021] Figure 7 is a front view of an insulated door coated with hot melt adhesive. As shown in Figure 7, hot melt adhesive 58 is applied linearly from the left edge to the right edge along the upper and lower edges of reinforcing plate 57. In this manner, hot melt adhesive 58 is applied to the outer periphery of reinforcing plate 57. This prevents foam insulation 55 (urethane) from entering the gap between outer panel 51 and reinforcing plate 57 from the top or bottom of reinforcing plate 57, even if foam insulation 55 (see Figure 4) is filled in space Y (see Figure 4), thereby reducing poor appearance of outer panel 51.

[0022] As described above, the insulated door 5a of the first embodiment includes the outer plate 51, the reinforcing plate 57 (intervening member) provided on the back side of the outer plate 51, and the hot melt adhesive 58 that bonds the outer plate 51 and the reinforcing plate 57. By using the hot melt adhesive 58, it is easier to automate the installation process than with conventional adhesive tape.

[0023] In the first embodiment, the space Y facing the rear surface of the outer panel 51 has foamed insulation 55 foamed in place. The outer panel 51 is made of a material that can be deformed by the pressure of foaming in place of the foamed insulation 55. A hot melt adhesive 58 is applied between the rear surface of the outer panel 51 and the reinforcing plate 57. This allows for automation of the attachment of the reinforcing plate 57 to the insulated door 5a made of steel or resin.

[0024] In the first embodiment, the thickness of the hot melt adhesive 58 in a solidified state is 0.1 mm or less, which makes it possible to prevent the foam insulation material 55 (urethane) from entering the gap between the outer panel 51 and the reinforcing plate 57 when the foam insulation material 55 is filled.

[0025] In the first embodiment, the space Y facing the rear surface of the outer panel 51 has foamed insulation 55 foamed in situ. The outer panel 51 is made of a material that can be deformed by the pressure of foaming in situ of the foamed insulation 55. The hot melt adhesive 58 is applied to the outer periphery of the reinforcing plate 57 between the rear surface of the outer panel 51 and the reinforcing plate 57. This prevents the foamed insulation 55 (urethane) from entering the gap between the outer panel 51 and the reinforcing plate 57.

[0026] In the first embodiment, the hot melt adhesive 58 is applied up to the edge of the reinforcing plate 57 (intervening member), which prevents the foam insulation 55 (urethane) from penetrating into the edge between the rear surface of the outer panel 51 and the reinforcing plate 57.

[0027] Figure 8 is a front view of the insulated door of the second embodiment. As shown in Figure 8, in the insulated door 5b of the second embodiment, a hot melt adhesive 58 is applied to the entire outer periphery of the reinforcing plate 57 between the back surface of the outer plate 51 and the reinforcing plate 57. In other words, the hot melt adhesive 58 is formed seamlessly in a rectangular frame shape. This makes it possible to prevent the foam insulation 55 from entering the gap between the outer plate 51 and the reinforcing plate 57. Furthermore, by applying the hot melt adhesive 58 to the edge of the reinforcing plate 57, it is possible to prevent the foam insulation 55 (urethane) from entering the edge between the back surface of the outer plate 51 and the reinforcing plate 57.

[0028] However, if the hot melt adhesive 58 is applied seamlessly to the entire outer periphery of the reinforcing plate 57, air will be trapped inside the hot melt adhesive 58. This air will thermally expand and contract, deforming the outer panel 51 and worsening its appearance. Furthermore, if the outer panel 51 is made of steel, the center tends to be convex outward (toward the front) during bending, which can easily allow air to enter. Therefore, the above-mentioned problems can be solved by replacing the insulated door 5b of the second embodiment with the insulated door 5c of the third embodiment. Figure 9 is a front view of the insulated door of the third embodiment.

[0029] 9, in the insulating door 5c of the third embodiment, the hot melt adhesive 58 is applied to the entire outer periphery of the reinforcing plate 57 between the back surface of the outer plate 51 and the reinforcing plate 57, and is also applied to the center between the back surface of the outer plate 51 and the reinforcing plate 57. Note that the hot melt adhesive 58 may be applied to the entire surface of the reinforcing plate 57 between the back surface of the outer plate 51 and the reinforcing plate 57. This prevents air from being trapped inside the reinforcing plate 57, thereby suppressing deformation of the outer plate 51 due to air expansion and contraction.

[0030] Fig. 10 is a cross-sectional view of an insulated door according to a fourth embodiment. As shown in Fig. 10, an insulated door 5d according to the fourth embodiment includes a vacuum insulator 56 on the back surface of a reinforcing plate 57. The vacuum insulator 56 and the reinforcing plate 57 are bonded together using a hot melt adhesive 59. The hot melt adhesive 59 can be the same type as the hot melt adhesive 58 described above. This makes it easier to automate the process than when double-sided tape is used in the past.

[0031] Note that hot melt adhesive 59 is provided between reinforcing plate 57 and vacuum insulation material 56, and because reinforcing plate 57 prevents deformation of outer plate 51, a gap through which foam insulation material 55 can penetrate may be formed between vacuum insulation material 56 and reinforcing plate 57. Furthermore, because hot melt adhesive 59 is provided between vacuum insulation material 56 and reinforcing plate 57, and because reinforcing plate 57 prevents deformation of outer plate 51, there is no need to set the thickness of hot melt adhesive 59 to 0.1 mm or less.

[0032] The present invention is not limited to the above-described embodiment, but includes various modifications. For example, in the above-described embodiment, the reinforcing plate 57 is used as an intervening member, but the intervening member may be a vacuum heat insulating material 56. That is, the vacuum heat insulating material 56 may be attached to the rear surface of the outer panel 51. In this case, a hot melt adhesive 58 is applied between the rear surface of the outer panel 51 and the vacuum heat insulating material 56 to bond them together. This makes it easier to automate the process than when adhesive tape is used for fixing them together as in the past.

[0033] In addition, although the present embodiment has been described with reference to an example in which the outer panel 51 is made of steel plate, the outer panel may be made of resin or glass. Even in cases in which the outer panel is made of resin or glass, by adhering a reinforcing plate as an intervening member to the rear surface of the outer panel using a hot melt adhesive, it becomes easier to automate the work compared to conventional attachment using adhesive tape.

[0034] 1 Refrigerator 2a, 2b, 3a, 4a, 5a, 6a Insulated door 51 Outer panel 55 Foam insulation material 56 Vacuum insulation material 57 Reinforcing plate (intervening member) 57a Edge (edge ​​of intervening member) 58 Hot melt adhesive (adhesive in a fluid state when applied) T Thickness Y Space

Claims

1. An insulated door comprising: an outer panel; an intervening member provided on the back side of the outer panel; and an adhesive that is in a fluid state when applied and bonds the outer panel and the intervening member.

2. An insulated door as described in claim 1, characterized in that the space facing the back surface of the outer panel has foamed insulation foamed on site, the outer panel has a material that can be deformed by the pressure of the foamed insulation foamed on site, and the adhesive is applied between the back surface of the outer panel and the intervening member.

3. The heat-insulating door according to claim 2, wherein the adhesive has a thickness of 0.1 mm or less in a solidified state.

4. An insulated door as described in claim 1, characterized in that the space facing the back surface of the outer panel has foamed insulation foamed on site, the outer panel has a material that can be deformed by the pressure of the foamed insulation foamed on site, and the adhesive is applied to the outer periphery of the intervening member between the back surface of the outer panel and the intervening member.

5. An insulated door as described in claim 1, characterized in that the space facing the back surface of the outer panel has foamed insulation foamed on site, the outer panel has a material that can be deformed by the pressure of the foamed insulation foamed on site, and the adhesive is applied to the entire outer periphery of the intervening member between the back surface of the outer panel and the intervening member.

6. An insulated door according to claim 5, characterized in that the adhesive is also applied to the center between the back surface of the outer panel and the intermediate member.

7. A heat-insulating door according to claim 5, characterized in that the adhesive is applied up to the edge of the intermediate member.

8. An insulated door as described in claim 1, comprising a vacuum insulation material provided on the back surface of the intervening member, and the intervening member and the vacuum insulation material are bonded together using the adhesive.

9. A refrigerator equipped with an insulating door according to any one of claims 1 to 8.

Images