Packing material for vacuum insulating glass and door for refrigeration case

Abstract

Provided are: a packing material for vacuum insulating glass which, even when the vacuum insulating glass is curved by a temperature difference, makes it possible to inhibit deterioration in insulating properties due to a gap formed between a door composed of a frame supporting the vacuum insulating glass and a refrigeration showcase body; and a door for refrigeration cases which employs the packing material. A packing material 21 for vacuum insulating glass comprises a base part 22 and a flexure part 23 having a lateral end affixed to the base part 22. The base part 22 has a polygonal cross section orthogonal to the longitudinal direction thereof. The flexure part 23 has an arc-shaped cross section orthogonal to the longitudinal direction thereof. The flexure part 23 has a lower hardness than the base part 22.

Description

Gasket for vacuum insulated glass and refrigerator case doors

[0001] The present disclosure relates to a packing material for vacuum insulating glass and a door for a refrigerated case using the same.

[0002] Among refrigerated cases that store food and other items at low temperatures, those used as sales showcases in stores often have a transparent glass plate fixed to a metal frame as an opening and closing door (hereinafter referred to as a "refrigerated case door") so that the stored products can be seen from the outside.

[0003] In such a refrigerating case door, the temperature inside the refrigerating case is likely to rise due to external light entering through the glass plate and heat from the outside air temperature transmitted through the glass plate. Therefore, it is preferable to use a glass plate with excellent heat insulating properties for the refrigerating case door.

[0004] In recent years, it has been proposed to use vacuum insulating glass as the glass plate for such refrigerated case doors (see, for example, Patent Documents 1 and 2). Vacuum insulating glass has excellent heat insulating properties even when it is thin, and therefore maintains good visibility from the outside.

[0005] JP 2009-236366 A JP 2010-063536 A

[0006] However, when thin vacuum insulated glass is used in the door of a refrigerated case, the temperature difference between the inside and outside of the glass panel is large, and the thin vacuum insulated glass, which is supported on the periphery by a frame, is prone to bending so that the center protrudes toward the outside.

[0007] As a result, gaps tend to form between the frame supporting the vacuum insulating glass and the refrigerated showcase body, resulting in a problem of reduced thermal insulation.

[0008] The present disclosure has been made in consideration of the above-mentioned problems, and aims to prevent a gap from occurring between the frame that supports the vacuum insulated glass and the refrigerated showcase body, thereby reducing the insulation properties, even if the vacuum insulated glass is warped due to a temperature difference.

[0009] A packing material for vacuum insulating glass according to one aspect of the present disclosure includes a base portion and a flexible portion having a side end fixed to the base portion. A cross section of the base portion perpendicular to the longitudinal direction thereof is polygonal. A cross section of the flexible portion perpendicular to the longitudinal direction thereof is arc-shaped. The flexible portion has a lower hardness than the base portion.

[0010] The refrigerated case door of one aspect of the present disclosure includes the vacuum insulating glass packing material, a frame having a U-shaped cross section perpendicular to the longitudinal direction and first and second opposing surfaces, and vacuum insulating glass. The base portion of the vacuum insulating glass packing material is fixed to the first surface of the frame. The peripheral edge of the vacuum insulating glass is held between the second surface of the frame and the flexible portion.

[0011] Fig. 1 is a perspective view of a refrigerated case door using a packing material for vacuum insulating glass according to an embodiment of the present disclosure. Fig. 2 is an enlarged cross-sectional view of a main part showing the packing material for vacuum insulating glass and its surrounding area taken along plane D in Fig. 1. Fig. 3 is a cross-sectional view showing an example of vacuum insulating glass. Fig. 4 is a schematic view showing a state in which a flexible portion of the packing material for vacuum insulating glass is flexible.

[0012] (One embodiment) Hereinafter, a packing material for vacuum insulating glass according to one embodiment of the present disclosure and a refrigerator case door using the same will be described with reference to the drawings. Note that the following embodiments are specifically described to provide a better understanding of the gist of the invention, and do not limit the present disclosure unless otherwise specified. For convenience, the drawings used in the following description may show essential parts enlarged to make the features of the present disclosure easier to understand, and the dimensional proportions of each component may not necessarily be the same as those in reality.

[0013] (Refrigerated Case Door) Fig. 1 is a perspective view of a refrigerated case door using a packing material for vacuum insulating glass according to one embodiment of the present disclosure. Fig. 2 is an enlarged cross-sectional view of a main part showing the packing material for vacuum insulating glass and its surrounding area taken on plane D in Fig. 1. Fig. 3 is a cross-sectional view showing an example of vacuum insulating glass.

[0014] The refrigerator case door 10 of one embodiment includes a vacuum insulating glass 11, a frame 12 that supports the peripheral edge of the vacuum insulating glass 11, and a packing material 21 for the vacuum insulating glass of one embodiment. Hereinafter, the packing material 21 for the vacuum insulating glass will be simply referred to as "packing material 21."

[0015] When the door 10 for a refrigerating case of one embodiment is used as an opening and closing door of a refrigerating case, it is attached so that the side on which the packing material 21 is arranged faces the outside of the refrigerating case.

[0016] The vacuum insulating glass 11 is made by intermittently providing pillars 32 between two float glass sheets 31 a, 31 b to form a gap, and bonding the peripheries of the float glass sheets 31 a, 31 b to each other with an adhesive layer 33. The gap between the float glass sheets 31 a, 31 b serves as a vacuum layer Q.

[0017] It is said that the vacuum insulating glass 11 can ensure the same or better thermal insulation properties as double insulating glass, which has gas sealed in the gaps between multiple glass panes, even if it is, for example, about one-quarter the thickness.

[0018] (Frame) The frame 12 is a frame-like member having a U-shaped cross section perpendicular to the longitudinal direction, and is formed integrally with opposing side plates 41, 42 and a connecting plate 43 connecting one ends of the side plates 41, 42. The side plates 41, 42 are preferably parallel to each other. The connecting plate 43 is preferably perpendicular to the side plates 41, 42. The side plates 41, 42 and the connecting plate 43 are preferably both flat plates.

[0019] Frame 12 has an open end facing connecting plate 43, and the peripheral edge of vacuum insulating glass 11 fits into frame 12 through this open end to hold the peripheral edge of vacuum insulating glass 11. Frame 12 is preferably made of a lightweight, high-strength material such as metal (e.g., aluminum alloy or stainless steel) or hard plastic.

[0020] The frame 12 has a first surface 41a and a second surface 42a that face each other. The first surface 41a is an inner surface 41a of the side plate 41. A base portion 22 of the packing material 21, which will be described later, is joined to the first surface 41a.

[0021] The sealing layer 13 is provided on the second surface 42a of the frame 12. The second surface 42a is the inner surface 42a of the side plate 42.

[0022] When the peripheral edge of the vacuum insulating glass 11 is sandwiched between the sealing layer 13 and a flexible portion 23 of the packing material 21 described below, the sealing layer 13 airtightly seals the peripheral edge on one side of the vacuum insulating glass 11 and the frame 12. The sealing layer 13 is preferably made of, for example, a sheet material made of a soft resin or a sheet material made of an elastic material such as rubber.

[0023] The frame 12 further includes a third surface 43a connecting the first surface 41a and the second surface 42a. The third surface 43a is an inner surface 43a of a connecting plate 43 of the frame 12.

[0024] The first surface 41 a and the second surface 42 a are preferably parallel to each other. The third surface 43 a is preferably perpendicular to the first surface 41 a and the second surface 42 a. The first surface 41 a, the second surface 42 a, and the third surface 43 a are preferably all flat.

[0025] A buffer layer 14 is provided on the third surface 43a. The buffer layer 14 abuts against the end face of the vacuum insulated glass 11 inserted inside the frame 12, or faces the end face of the vacuum insulated glass 11 inserted inside the frame 12 with a gap between them. The buffer layer 14 prevents cracks or chips from occurring when the end face of the vacuum insulated glass 11 comes into direct contact with the hard frame 12. The buffer layer 14 is preferably made of a sheet material made of, for example, a soft resin or an elastic material such as rubber.

[0026] (Packing material for vacuum glass) In one embodiment, the packing material 21 is a member that extends in the longitudinal direction of the frame body 12 inside the frame body 12, and includes a base portion 22 and a flexible portion 23 fixed to the base portion 22.

[0027] (Base portion) The base portion 22 is a member whose cross section perpendicular to its longitudinal direction forms a polygon. In one embodiment, the base portion 22 is formed so that its cross section perpendicular to the longitudinal direction forms a rectangle. The base portion 22 is preferably hollow. The bottom surface of the base portion 22 is joined to the first surface 41a of the frame body 12 (i.e., the inner surface 41a of the side plate 41), thereby fixing the packing material 21 to the frame body 12. Note that the side surface of the base portion 22 facing the third surface 43a of the frame body 12 may be either joined or not joined to the third surface 43a.

[0028] The base portion 22 is preferably made of a material, such as a hard resin, that is harder than the material of the flexible portion 23. In one embodiment, the base portion 22 is made of a hard polyvinyl chloride resin.

[0029] (Flexible portion) The flexible portion 23 is a member having an arc-shaped cross section perpendicular to its longitudinal direction. In one embodiment, the flexible portion 23 is formed so that the cross section perpendicular to the longitudinal direction is an arc-shaped cross section. Both side ends of the flexible portion 23 are fixed to the upper surface of the base portion 22. A gap is formed between the flexible portion 23 and the base portion 22.

[0030] 2 is located inside an end surface 22m of the base 22 in the width direction W (in other words, an end surface 22m along the height direction H). This positional relationship can be maintained both when no stress is applied to the flexible portion 23 and when the flexible portion 23 is bent in the height direction H so as to crush the arc shape due to stress applied by the curvature of the vacuum insulating glass 11.

[0031] The flexible portion 23 is preferably made of a soft material, such as a soft resin, that is lower in hardness than the material of the base portion 22. In one embodiment, the flexible portion 23 is made of a soft polyvinyl chloride resin.

[0032] Furthermore, when the height of base 22 in the direction in which base 22 and flexible portion 23 overlap, i.e., in height direction H, is Hs and the height of flexible portion 23 is Hm, base 22 and flexible portion 23 are preferably formed so that the ratio of Hs to Hs+Hm, i.e., the ratio of the height of base 22 to the height of packing material 21 for vacuum insulating glass, is within the range of 40% to 65%. Note that this ratio range is preferably satisfied at least before packing material 21 is incorporated into frame 12.

[0033] In one embodiment, the base portion 22 and the flexible portion 23 of the packing material 21 are preferably integrally molded. In other words, it is preferable that the integral packing material 21 includes the base portion 22 and the flexible portion 23. For example, the packing material 21 can be obtained by extrusion molding of different materials, such as a hard polyvinyl chloride resin (the material of the base portion 22) and a soft polyvinyl chloride resin (the material of the flexible portion 23).

[0034] (Effects) According to the refrigerated case door 10 using the packing material 21 for vacuum insulating glass of one embodiment as described above, when using vacuum insulating glass 11 which is thinner than conventional double-pane insulating glass and which tends to bend more depending on the temperature difference between inside and outside, even if the stress applied to the packing material 21 increases, the shape of the packing material 21 can be maintained as much as possible, and a decrease in insulating properties such as leakage of cold air from the frame 12 can be suppressed.

[0035] For example, even if the temperature difference between the inside and outside of the refrigerated case door 10 causes the central portion of the vacuum insulated glass 11 to bend and protrude, as shown in the schematic diagram of Figure 4, causing the peripheral portion of the vacuum insulated glass 11 to tilt with respect to the width direction W and applying stress to the packing material 21, because the packing material 21 includes a hard base portion 22 and a softer flexible portion 23, the base portion 22 can maintain the shape of the packing material 21 as much as possible, while the flexible portion 23 can bend and accommodate the curvature and deformation of the vacuum insulated glass 11.

[0036] This prevents gaps from forming between the refrigerated case door 10 and the refrigerated showcase body, thereby preventing a decrease in thermal insulation. In addition, the hard base 22 of the packing material 21 prevents the entire packing material 21 from deforming and becoming unable to maintain its shape.

[0037] In addition, because the outermost portion of the flexible portion 23 in the width direction W is located inside the end face 22m of the base portion 22, even if the flexible portion 23 is bent due to the curvature of the vacuum insulated glass 11, the flexible portion 23 does not protrude significantly from the frame body 12 in the width direction W. Therefore, even if the side on which the packing material 21 is arranged is attached to the outside of the refrigerated case, the protrusion of the flexible portion 23 is prevented from being visible from the outside of the refrigerated case, and an excellent aesthetic effect can be achieved.

[0038] (Modifications) In the above-described embodiment, the cross-sectional shape of the base portion 22 of the packing material 21 is rectangular, but it may be any polygonal shape, such as a rectangle, a triangle, a pentagon, a hexagon, etc. The cross-sectional shape of the base portion 22 is not particularly limited as long as it supports the flexible portion 23 and is suppressed from deforming even when stress is applied due to the curvature of the vacuum insulating glass 11.

[0039] In the above-described embodiment, the cross-sectional shape of the flexible portion 23 constituting the packing material 21 is an arc, but this is not limited thereto and any arc shape may be used. For example, the cross-sectional shape of the flexible portion 23 may be a semicircular shape, an arc shape with a circumferential angle smaller than 180°, an arc shape with a circumferential angle larger than 180°, an elliptical arc, etc. The cross-sectional shape of the flexible portion 23 can be selected appropriately depending on conditions such as the shape change after bending and strength.

[0040] Furthermore, if the cross-sectional shape of the flexible portion 23 is arc-shaped, the contact area with the vacuum insulating glass 11 is larger than when the cross-sectional shape is triangular or the like, thereby preventing the vacuum insulating glass 11 from slipping relative to the flexible portion 23.

[0041] In addition, in the above-described embodiment, the packing material 21 is joined to the frame body 12, but it is also possible to abut the packing material 21 against the frame body 12 without joining it to the frame body 12. In this case, the packing material 21 is fixed to the frame body 12 by fitting the vacuum insulating glass 11 into the packing material 21.

[0042] Although one embodiment and various modifications of the present disclosure have been described above, these are presented as examples and are not intended to limit the scope of the invention. These embodiments and various modifications can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and various modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims.

[0043] As described above based on one embodiment and various modified examples, the packing material (21) for vacuum insulating glass according to a first embodiment includes a base portion (22) and a flexible portion (23) having side ends fixed to the base portion (22). A cross section of the base portion (22) perpendicular to the longitudinal direction is polygonal. A cross section of the flexible portion (23) perpendicular to the longitudinal direction is arc-shaped. The flexible portion (23) has a lower hardness than the base portion (22).

[0044] In the packing material (21) for vacuum insulating glass according to the second aspect, the cross section of the base portion (22) perpendicular to the longitudinal direction of the first aspect is rectangular, and the cross section of the flexible portion (23) perpendicular to the longitudinal direction is arc-shaped.

[0045] In the packing material (21) for vacuum insulating glass according to the third aspect, the base portion (22) and the flexible portion (23) in the first or second aspect are integrally formed.

[0046] In the packing material (21) for vacuum insulating glass according to the fourth aspect, in any one of the first to third aspects, the ratio of the height (Hs) of the base portion (22) to the height of the packing material (21) for vacuum insulating glass is in the range of 40% or more and 65% or less.

[0047] In the packing material (21) for vacuum insulating glass according to the fifth aspect, in any one of the first to fourth aspects, the outermost part of the flexible portion (23) in the width direction (W) is located inside the end face (22m) of the base portion (22) in the width direction (W).

[0048] In a sixth aspect of the packing material (21) for vacuum insulating glass according to any one of the first to fifth aspects, the base portion (22) is made of hard polyvinyl chloride resin, and the flexible portion (23) is made of soft polyvinyl chloride resin.

[0049] A refrigerated case door (10) according to a seventh aspect includes a vacuum insulating glass packing (21) according to any one of the first to sixth aspects, a frame (12) having a U-shaped cross section perpendicular to the longitudinal direction and having a first surface (41 a) and a second surface (42 a) facing each other, and vacuum insulating glass (11). A base portion (22) of the vacuum insulating glass packing (21) is fixed to the first surface (41 a) of the frame (12). A peripheral portion of the vacuum insulating glass (11) is held between the second surface (42 a) of the frame (12) and a flexible portion (23).

[0050] In the refrigerating case door (10) according to the eighth aspect, in the seventh aspect, the frame (12) further has a third surface (43a) connecting the first surface (41a) and the second surface (42a). The third surface (43a) is provided with a buffer layer (14) that can abut against an end surface of the vacuum insulating glass (11) in the thickness direction.

[0051] In the ninth aspect of the refrigerated case door (10), in the seventh or eighth aspect, a sealing layer (13) is provided on the second surface (42a) of the frame (12) so as to face the flexible portion (23) of the packing material (21) for vacuum insulating glass.

[0052] REFRIGERATED CASE DOOR 11 VACUUM INSULATED GLASS 12 FRAME 13 SEALING LAYER 14 CUSHIONING LAYER 21 GASHER (GASKET FOR VACUUM INSULATED GLASS) 22 BASE 22m END SURFACE 23 FLEXURE 41a 1ST SURFACE 42a 2ND SURFACE 43a 3RD SURFACE H HEIGHT DIRECTION W WIDTH DIRECTION Hs HEIGHT OF BASE

Claims

1. A packing material for vacuum insulating glass comprising: a base portion; and a flexible portion having side ends fixed to the base portion, wherein a cross section perpendicular to the longitudinal direction of the base portion is polygonal, a cross section perpendicular to the longitudinal direction of the flexible portion is arc-shaped, and the flexible portion has a hardness lower than that of the base portion.

2. The packing material for vacuum insulating glass according to claim 1, wherein a cross section of the base portion perpendicular to the longitudinal direction is rectangular, and a cross section of the flexible portion perpendicular to the longitudinal direction is arc-shaped.

3. A packing material for vacuum insulating glass according to claim 1 or 2, wherein the base portion and the flexible portion are integrally formed.

4. A packing material for vacuum insulating glass as claimed in claim 3, wherein the ratio of the height of said base portion to the height of said packing material for vacuum insulating glass is within the range of 40% to 65%.

5. A packing material for vacuum insulating glass as claimed in claim 3, wherein the outermost portion in the width direction of the flexible portion is located inside the end face in the width direction of the base portion.

6. A packing material for vacuum insulating glass according to claim 1 or 2, wherein the base portion is made of hard polyvinyl chloride resin, and the flexible portion is made of soft polyvinyl chloride resin.

7. A door for a refrigerator case comprising: a packing material for vacuum insulating glass as recited in claim 1 or 2; a frame having a U-shaped cross section perpendicular to the longitudinal direction and having first and second surfaces opposing each other; and vacuum insulating glass, wherein the base part of the packing material for vacuum insulating glass is fixed to the first surface of the frame, and the peripheral edge of the vacuum insulating glass is held between the second surface of the frame and the flexible part.

8. The door for a refrigerating case as claimed in claim 7, wherein the frame further has a third surface connecting the first surface and the second surface, and the third surface is provided with a buffer layer capable of coming into contact with an end surface of the vacuum insulating glass in the thickness direction.

9. The door for a refrigerating case according to claim 7, wherein a seal layer is provided on the second surface of the frame so as to face the flexible portion of the packing material for vacuum insulating glass.

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