JP7027166B2 - Glass door for freezing showcase - Google Patents

Description

The present invention relates to a glass door for a freezing showcase.

Conventionally, various products (beverages, fresh foods, frozen foods, etc.) are stored and sold in cold storage showcases at convenience stores and the like. The cold storage showcase has a door consisting of a sash and a glass plate on the front, and a handle is attached to the front of the sash. By opening and closing this handle, the door can be opened and closed back and forth. In addition, since the door is mostly made of glass except for the sash on the periphery, the user can identify and select the products in the refrigerator without opening the door.

As a double glazing structure used for a cold storage showcase, for example, a first glass plate located inside the cold storage showcase and a first glass plate facing the first glass plate across a space and located on the outside of the storage. A double glazing structure including a second glass plate and a third glass plate facing the second glass plate with a space apart and further located on the outside of the refrigerator is known (for example, Patent Document). See 1).

Japanese Patent No. 5424059

However, in the double glazing structure described in Patent Document 1, the distance between the first glass plate and the second glass plate and the distance between the second glass plate and the third glass plate are the same. Therefore, when it is used as a refrigerating showcase, there is a problem that the heat insulation efficiency is lowered due to the decrease in the volume of the space due to the temperature difference between the inside and outside of the refrigerator.

Therefore, an object of the present invention is to provide a glass door for a freezing showcase that can prevent a decrease in heat insulation efficiency caused by a temperature difference between the inside and outside of the freezing showcase during the freezing operation of the freezing showcase.

In order to achieve the above object, the glass door for a freezing showcase according to one aspect of the present invention is
A first glass plate arranged on the outside of the freezing showcase,
A second glass plate arranged inside the freezing showcase,
It has a first glass plate and a third glass plate arranged apart from the second glass plate between the first glass plate and the second glass plate.
The first distance between the outer surface of the first glass plate and the center line in the thickness direction of the third glass plate, the inner surface of the second glass plate, and the third. The second distance between the glass plate and the center line in the thickness direction is different.

According to the present invention, the heat insulating performance can be improved without increasing the thickness of the glass door.

It is a side sectional view which showed an example of the glass door for a freezing showcase which concerns on a reference example. It is a side sectional view which showed an example of the glass door for a freezing showcase which concerns on 1st Embodiment of this invention. It is a figure which showed the heat insulation property of Kr gas, Ar gas, and dry air. It is a side sectional view which showed an example of the glass door for a freezing showcase which concerns on 2nd Embodiment of this invention. It is a side sectional view which showed an example of the glass door for a freezing showcase which concerns on 3rd Embodiment of this invention. It is a side sectional view which showed an example of the glass door for a freezing showcase which concerns on 4th Embodiment of this invention. It is a side sectional view which showed an example of the glass door for a freezing showcase which concerns on 5th Embodiment of this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

First, before explaining in detail the glass door for a freezing showcase according to the embodiment of the present invention, the glass door for a freezing showcase according to a reference example generally used conventionally will be described.

FIG. 1 is a side sectional view showing an example of a glass door for a freezing showcase according to a commonly used reference example. The glass door for the refrigeration showcase according to the reference example was arranged between the glass plate 10 on the outside of the refrigerator showcase, the glass plate 20 on the inside of the refrigerator, and the glass plate 10 on the outside and the glass plate 20 on the inside of the refrigerator. It is provided with a central glass plate 30. Here, the outside of the refrigerator means the outside of the freezing showcase, and the inside of the refrigerator means the inside of the freezing showcase.

Spacers 40 and 41 are arranged between the outer glass plate 10 and the central glass plate 30 and between the inner glass plate 20 and the central glass plate 30, respectively, and the outer glass plate 10 and the central glass plate 30 are arranged. The distance d3 between the two and the inside glass plate 20 and the central glass plate 30 is maintained.

The lower ends of the glass plates 10, 20, 30 and the spacers 40, 41 are held by the door stile 50. The door stile 50 is composed of a holding member 51 that holds the glass plates 10 to 30 and the spacers 40 and 41, and a support member 52 that supports the holding member 51. The sandwiching member 51 is made of, for example, a resin such as polyvinyl chloride (PVC). The support member 52 is made of, for example, aluminum or the like so that the glass plates 10 to 30 and the spacers 40 and 41 can be reliably supported via the holding member 51 and the heat from the internal cord heater 60 can be transferred. It is composed of metal.

A cord heater 60 is installed on the support member 52 of the door stile 50 so that it can be heated. By heating the cord heater 60, it is possible to prevent dew condensation from forming on the door stile 50 during the freezing operation of the freezing showcase.

A frame frame 80 is provided so as to surround the inside and the side surface of the door frame 50. The frame frame 80 is configured by fitting two members 81 and 82, and the gasket receiving surface 83 is sandwiched between the member 81 and the member 82. A cord heater 61 is installed on the member 82 in order to prevent dew condensation on the frame frame 80. Therefore, the member 82 is preferably made of a metal such as aluminum having high thermal conductivity, and the other member 81 may be made of a resin such as polyvinyl chloride. The gasket receiving surface 83 is made of a magnetic material.

The magnet gasket 70 is attached to the side surface of the inside of the door frame 50 and is a sealing member for maintaining the sealing property between the glass door and the frame frame 80 when the glass door is closed. The magnet gasket 70 attracts the gasket receiving surface 83 by magnetic force, and maintains the sealing property between the magnet gasket 70 and the gasket receiving surface 83.

In the glass door for a freezing showcase according to the reference example having such a configuration, the glass plates 10 to 30 have the same thickness, and the distance d3 between the outer glass plate 10 and the central glass plate 30 , The distance d4 between the inner glass plate 20 and the central glass plate 30 is the same size. That is, the glass plates 10 to 30 have a symmetrical arrangement configuration in which the entire glass plate 10 to 30 is balanced and has no bias in the thickness direction. Here, assuming that the total thickness is 25 mm, the distance between the outer surface of the outer glass plate 10 and the center line (more accurately, the center surface or the surface including the center line) 30C in the thickness direction of the central glass. The distance d2 between d1 and the outer surface (the surface inside the refrigerator) of the inner glass plate 20 and the center line 30C in the thickness direction of the central glass is also balanced, and the distance d1 and the distance d2 are equal.

Here, the thicknesses of the outer side glass plate 10, the inner side glass plate 20, and the central glass plate 30 are all 3 mm, and the inner surface of the outer side glass plate 10 and the outer side surface of the central glass plate 30 The distance d3 between them and the distance d4 between the inner surface (outer surface) of the inner glass plate 10 and the inner surface of the central glass plate 30 are both equal to 8 mm, and the distances d3 and d4 are equal to each other. Is balanced without bias. Further, the distance d1 between the outer surface of the outer glass plate 10 (outer surface) and the center line 30C in the thickness direction of the central glass 30 and the outer surface of the inner glass plate 20 (inner surface). ) And the distance d2 between the center line 30C in the thickness direction of the central glass 30 are both equal to 3 + 8 + 1.5 = 12.5 mm, and the distances d1 and d2 are also balanced without any bias. As described above, the door portion of the glass door for a freezing showcase is generally manufactured in a symmetrical balance between the outside and the inside of the refrigerator in the thickness direction.

However, the glass door for the freezing showcase is manufactured in an environment of about 23 ± 2 ° C. When this is used as a glass door for a freezing showcase that is frozen at an internal temperature of approximately -25 ° C, the temperature difference from the external temperature of approximately 25 ° C becomes large, and according to Boyle-Charles' law, the internal glass plate 20 The volume of the hollow layer S2 inside the refrigerator between the central glass plate 30 and the central glass plate 30 is reduced. As a result, the air layer (gas layer) of the hollow layer S2 inside the refrigerator is reduced, which causes a problem that the heat insulating efficiency of the hollow layer S2 inside the refrigerator is lowered.

In the glass door for a refrigerating showcase according to the embodiment of the present invention, the distance d1 between the outer surface (outer surface) of the outer glass plate 10 and the center line in the thickness direction of the central glass plate 30 and the storage. An imbalance is caused between the outer surface (inner surface of the refrigerator) of the inner glass plate 20 and the distance d2 between the center line and the center line in the thickness direction of the central glass plate 30 to prevent such a decrease in heat insulation efficiency. The specific contents will be described below.

[First Embodiment]
FIG. 2 is a side sectional view showing an example of a glass door for a freezing showcase according to the first embodiment of the present invention. In FIG. 2, the positions and configurations of the outer glass plate 10 and the inner glass plate 20 are the same as those in FIG. 1, but the position of the central glass plate 30 approaches the inner glass plate 20 and the outer glass. The distance d1 from the plate 10 and the distance d2 from the inner glass plate 20 are different from each other, resulting in an imbalance between the two. Specifically, the distance d3 between the inner surface of the outer glass plate 10 and the outer surface of the central glass plate is 10 mm, and the inner surface (outer surface) and the center of the inner glass plate 20 are. The distance d4 between the inner surface of the glass plate and the inner surface of the glass plate is 6 mm, and d4 <d3. Further, the distance d1 between the outer surface of the outer glass plate 10 and the center line 30C in the thickness direction of the central glass plate 20 is 3 + 10 + 1.5 = 14.5 mm, and the outer surface of the inner glass plate 20 (the refrigerator). The distance d2 between the inner surface) and the center line 30C in the thickness direction of the central glass plate 20 is 3 + 6 + 1.5 = 10.5 mm, and d2 <d1 as well. With this configuration, the volume of the hollow layer S2 between the inner glass plate 20 and the central glass plate 30 becomes smaller than the volume of the hollow layer S1 between the outer glass plate 10 and the central glass plate 30. It is possible to reduce the relative decrease in the volume of the air layer (gas layer) of the hollow layer S2 due to the cooling of the inside. As a result, even if a large temperature difference occurs between the outside of the refrigerator and the inside of the refrigerator, the difference in the amount of decrease in the air layer (gas layer) between the hollow layer S1 and the hollow layer S2 becomes small, and the decrease in heat insulation efficiency inside the refrigerator is prevented. be able to.

The hollow layers S1 and S2 are generally filled with krypton (Kr) gas, respectively. When Kr gas is sealed in the hollow layers S1 and S2, the distance d3 between the outer glass plate 10 and the central glass plate 30 or the distance d4 between the inner glass plate 20 and the central glass plate 30 is approximately 10 mm. At that time, the present inventors have found that the gas layer of Kr gas in the hollow layers S1 and S2 is optimized and the heat insulating performance is the best. Therefore, in the glass door for the freezing showcase according to the first embodiment, an example in which the distance d3 between the outer glass plate 10 and the central glass plate 30 is set to 10 mm is described.

However, the installation position of the central glass plate 30 is not limited to the example shown in FIG. 2, and the distance d3 between the outer glass plate 10 and the central glass plate 30 and the inner glass plate 20 and the central glass are not limited to the example shown in FIG. It can be installed at various positions as long as the arrangement is biased to the distance d4 between the plates 30 and causes an imbalance. In this case, the value obtained by dividing the distance d3 between the outer glass plate 10 and the central glass plate 30 by the distance d4 between the inner glass plate 20 and the central glass plate 30 may be more than 1.0. , 1.1 or more, 1.2 or more, 1.4 or more, 1.6 or more. Further, it may be 2.2 or less, 2.0 or less, or 1.8 or less. Further, in the present embodiment, an arrangement example in which the distance d4 between the inner glass plate 20 and the central glass plate 30 is narrower than the distance d3 between the outer glass plate 10 and the central glass plate 30 is given. As described above, depending on the application, the distance d3 between the outer side glass plate 10 and the central glass plate 30 may be narrower than the distance d4 between the inner side glass plate 20 and the central glass plate 30. good. In this case, the value obtained by dividing the distance d3 between the outer glass plate 10 and the central glass plate 30 by the distance d4 between the inner glass plate 20 and the central glass plate 30 may be less than 1.0. , 0.9 or less, 0.85 or less, 0.8 or less, 0.7 or less, 0.65 or less. .. Further, it may be 0.4 or more, 0.5 or more, or 0.55 or more.

Further, these relationships are related to the distance d1 between the outer surface of the outer glass plate 10 and the center line 30C in the thickness direction of the central glass 30 and the outer surface (inner surface) of the inner glass plate 20. ) And the distance d2 between the center line 30C in the thickness direction of the central glass plate 30. As long as the distance d1 and the distance d2 are different from each other and are biased to each other and an imbalance occurs, various arrangement configurations can be used.

Further, as the gas to be sealed in the hollow layers S1 and S2, other types of gas such as Ar gas may be used in addition to Kr gas. When Ar gas is sealed in the hollow layers S1 and S2, the present inventors have a distance d3 between the outer glass plate 10 and the central glass plate 30 or between the inner glass plate 20 and the central glass plate 30. It has also been found that when the interval d4 is approximately 15 mm, the gas layer of Ar gas in the hollow layers S1 and S2 is optimized, and the heat insulating performance is the best.

FIG. 3 is a diagram showing the heat insulating properties of Kr gas, Ar gas and dry air. In FIG. 3, the horizontal axis shows the distances d3 and d4 between the outer glass plate 10 or the inner glass plate 20 and the central glass plate 30, and the vertical axis shows the heat insulating performance. As shown in FIG. 3, Kr gas has the highest heat insulating performance when the intervals d3 and d4 are 9 to 11 mm, and Ar gas has the highest heat insulating performance when the intervals d3 and d4 are 14 to 16 mm. It shows the characteristics of. Further, the dry air has the highest heat insulating performance when the intervals d3 and d4 are 15 to 17 mm. For example, if the gas enclosed in the hollow layers S1 and S2 has the heat insulating characteristics as shown in FIG. 3 and the intervals d3 and d4 are set accordingly, at least one of the hollow layers on the outside or inside of the refrigerator is formed. The heat insulating performance of S1 and S2 can be set to the optimum condition, and the heat insulating performance of the glass door can be effectively improved. As described above, the gas enclosed in the hollow layers S1 and S2 may be another gas such as Ar gas in addition to Kr gas, and the installation position of the central glass plate 30 at that time considers the gas to be enclosed, the application, and the like. It can be in various suitable positions.

Since the other components are the same as the glass door for the freezing showcase according to the comparative example described with reference to FIG. 1, the same reference numerals are given to the same components and the description thereof will be omitted.

According to the glass door for a freezing showcase according to the first embodiment of the present invention, the position of the central glass plate 30 is unbalanced between the outside and the inside of the refrigerator without changing the total thickness to 25 mm. By arranging it in an appropriate position, the heat insulating performance can be improved. In particular, by arranging the central glass plate 30 so that the volume of the hollow layer S2 inside the refrigerator is smaller than the volume of the hollow layer S1 outside the refrigerator, the heat insulating property of the hollow layer S2 inside the refrigerator during freezing is enhanced. Can be done.

[Second Embodiment]
FIG. 4 is a side sectional view showing an example of a glass door for a freezing showcase according to a second embodiment of the present invention. In FIG. 4, in the glass door for a refrigerating showcase according to the second embodiment, the thickness of the central glass plate 31 is 1 mm, and the distance between the inner glass plate 20 and the central glass plate 31. It differs from the glass door for a refrigerating showcase according to the first embodiment in that d4 is 6 mm to 8 mm. On the other hand, in the glass door for the refrigerating showcase according to the second embodiment, the outer glass plate 10 and the inner glass plate 20 each have a plate thickness of 3 mm, and the whole is arranged at both ends having a thickness of 25 mm. The point that the distance d3 between the outer glass plate 10 and the central glass plate 31 is 10 mm is the same as that of the glass door for the refrigerating showcase according to the first embodiment.

The central glass plate 31 is provided between the outer side glass plate 10 and the inner side glass plate 20, and is protected from contact by the user, so that the outer side of the case is not necessarily the outer side of the case. It does not have to have the same strength as the glass plate 10 and the inner glass plate 20. Further, by making the central glass plate 31 thin, the weight of the glass door can be reduced. Therefore, in the glass door for the freezing showcase according to the second embodiment, the central glass plate 31 is made thinner than the outer side glass plate 10 and the inner side glass plate 20, so that the hollow layer S1 on the outer side of the refrigerator and the glass door 20 on the inner side of the refrigerator are thinner. It causes an imbalance with the inner hollow layer S2.

In the glass door for a freezing showcase according to the second embodiment, it can be said that an imbalance is caused between the outside and the inside of the refrigerator by reducing the thickness of the central glass plate 31. That is, in the glass door for the refrigerating showcase according to the reference example of FIG. 1, the thickness of the central glass plate 30 is 3 mm, the distance d3 between the outer glass plate 10 and the central glass plate 30 and the inner glass. The distance d4 between the plate 20 and the central glass plate 30 was 8 mm. On the other hand, in the glass door for the refrigerating showcase according to the second embodiment, the plate thickness of the central glass plate 31 is reduced by 2 mm, and the thinned 2 mm portion is added to the hollow layer S1 to add the thinned glass plate 20 to the inner glass plate 20. The distance d4 between the and the central glass plate 30 is maintained at 8 mm, while the distance d3 between the outer glass plate 10 and the central glass plate 31 is increased by 2 mm to 10 mm. Also in this case, d4 <d3, and the volume of the hollow layer S2 inside the refrigerator is smaller than the volume of the hollow layer S1 outside the refrigerator, so that the amount of volume change during freezing can be reduced. , The heat insulating property of the hollow layer S2 inside the refrigerator can be improved.

By reducing the plate thickness of the central glass plate 31 in this way, an imbalance may occur between the space d3 of the hollow layer S1 on the outside of the refrigerator and the space d4 of the hollow layer S2 on the inside of the refrigerator. Even in this case, the total thickness of the glass door remains constant at 25 mm, and the distance d1 between the outer surface of the outer glass plate 10 and the center line 31C in the thickness direction of the central glass plate 31 is 3 + 10 + 0. While .5 = 13.5 mm, the distance d2 between the outer surface (inner surface) of the inner glass plate 20 and the center line 31C in the thickness direction of the central glass plate 31 is 3 + 8 + 0. 5 = 11.5 mm, the distance d1 and the distance d2 are different (d2 <d1), and an imbalance occurs.

Also in the glass door for the freezing showcase according to the second embodiment, the distance d3 between the outer glass plate 10 and the central glass plate 31 is set to 10 mm, and Kr gas is used in the hollow layers S1 and S2. The hollow layer S1 is set so that the optimum heat insulating performance can be obtained when it is enclosed in the hollow layer S1.

However, as described in the description of the glass door for the freezing showcase according to the first embodiment, the gas enclosed in the hollow layers S1 and S2 shall be various gases including Ar gas and the like depending on the application. Can be done. Therefore, the distance d3 between the outer side glass plate 10 and the central glass plate 31, the distance d4 between the inner side glass plate 20 and the central glass plate 30, and the distance d4 between the inner side glass plate 20 and the central glass plate 30 are determined according to various conditions such as application and enclosed gas. The distance d1 between the outer surface of the outer glass plate 10 and the center line 31C in the thickness direction of the central glass plate 31 and the outer surface (inner surface) of the inner glass plate 20 and the central glass plate 31. The distance d2 from the center line 31C in the thickness direction can be set to various values. This point is the same as the glass door for the refrigerating showcase according to the first embodiment. Further, the thickness of the central glass plate 31 is not limited to 1 mm, and can be configured to have various thicknesses depending on the application as long as it is thinner than the outer side glass plate 10 and the inner side glass plate 20. .. The central glass plate 31 may have various thicknesses, but may be formed, for example, to have a thickness of 0.8 mm or more and 2 mm or less, preferably 1.1 mm or more and 2 mm or less.

According to the glass door for a refrigerating showcase according to the second embodiment, the thickness of the central glass plate 31 is made thinner than the thickness of the outer side glass plate 10 and the inner side glass plate 20 to make the glass door thinner. While reducing the weight and manufacturing cost, it is possible to cause an imbalance between the hollow layer S1 inside the refrigerator and the hollow layer S2 inside the refrigerator, and improve the heat insulating performance of the glass door.

[Third Embodiment]
FIG. 5 is a side sectional view showing an example of a glass door for a freezing showcase according to a third embodiment of the present invention. As for the glass door for the refrigerating showcase according to the third embodiment, the arrangement and the thickness of the outer glass plate 11, the inner glass plate 20 and the central glass plate 31 are the glass for the refrigerating showcase according to the second embodiment. It is the same as the door, but is different from the glass door for the refrigerating showcase according to the second embodiment in that laminated glass is used for the outer glass plate 11.

Laminated glass is glass formed by joining a pair of glass plates via an interlayer film made of resin. Since the glass plate on the surface is bonded to the interlayer film made of resin, even if the glass plate on the surface is broken, the glass plate does not scatter and the state of being bonded to the interlayer film can be maintained. Therefore, the laminated glass is a highly safe glass and is often used as an outer glass plate that has many contacts with the user.

In FIG. 5, the pair of glass plates 11a and 11b are joined to each other via an interlayer film 11c made of resin to form the outer glass plate 11. The outer glass plate 11 is composed of 3 mm as a whole, and the overall arrangement of the outer glass plate 11, the inner glass plate 20 and the central glass plate 31 is the freezing showcase according to the second embodiment. Since it is the same as the glass door for a glass door, it can have the same heat insulating performance as the glass door for a refrigerating showcase according to the second embodiment. In addition to this, since the safety when the outer glass 11 is damaged is high, both the improvement of the heat insulating performance and the improvement of the safety can be realized.

Since other components and detailed contents are the same as those in the second embodiment, the same reference numerals are given to the same components and the description thereof will be omitted.

As described above, according to the glass door for the freezing showcase according to the third embodiment, by forming the outer glass plate 11 of the refrigerator, which has many contacts with the user, into laminated glass, the heat insulating performance is improved and the safety is improved. It can also be improved.

[Fourth Embodiment]
FIG. 6 is a side sectional view showing an example of a glass door for a freezing showcase according to a fourth embodiment of the present invention. In the glass door for the freezing showcase according to the fourth embodiment, the outer glass plate 10 is still 3 mm and the central glass plate 31 is still 1 mm, but the inner glass plate 21 is changed from 3 mm to 1 mm. In that respect, it is different from the glass door for the freezing showcase according to the second embodiment.

The inner glass plate 21 does not come into frequent contact with the user like the outer glass plate 10, but since it constitutes the outer surface of the glass door, it requires higher strength than the central glass plate 31 which is not exposed on the surface. Will be done. However, by using chemically tempered glass, it is possible to obtain a glass plate having sufficient strength even if the plate thickness is reduced. In the present embodiment, the inner glass plate 21 is made of such chemically strengthened glass to have a thickness of 1 mm, similar to the central glass plate 31.

As shown in FIG. 6, by setting the inner glass plate 21 to 1 mm, the distance d3 between the outer glass plate 10 and the central glass plate 31 and the refrigerator 31 while keeping the total thickness of the glass door 25 mm. Both of the distance d4 between the inner glass plate 21 and the central glass plate 31 can be set to 10 mm. Therefore, if Kr gas is sealed in the hollow layer S1 between the outer glass plate 10 and the central glass plate 31 and the hollow layer S2 between the inner glass plate 21 and the central glass plate 31, the hollow layer on the outer side of the refrigerator The heat insulating performance of both S1 and the hollow layer S2 inside the refrigerator can be optimized, and very high heat insulating performance can be realized.

In the fourth embodiment, the distance d3 and the distance d4 are equal, but the distance d1 between the outer surface of the outer glass plate 10 and the center line 31C in the thickness direction of the central glass plate 31 is 3 + 10 + 0. While 5 = 13.5, the distance d2 between the outer surface (inner surface) of the inner glass plate 21 and the center line 31C in the thickness direction of the central glass plate 31 is 1 + 10 + 0.5. = 11.5, and both are unbalanced. In this way, by thinning the inner glass plate 21 in addition to the central glass plate 31, the distance between the outer surface of the outer glass plate 10 and the center line 31C in the thickness direction of the central glass plate 31. While creating an imbalance between d1 and the distance d2 between the outer surface (inner surface) of the inner glass plate 21 and the center line 31C in the thickness direction of the central glass plate 31, the outer surface of the refrigerator The hollow layers S1 and S2 inside the refrigerator may be configured to realize optimum heat insulation performance.

According to the glass door for a refrigerating showcase according to the fourth embodiment, not only the central glass plate 31 is made thin, but also the inner glass plate 21 is made thin by using chemically strengthened glass. Optimal heat insulation performance can be realized in the hollow layers S1 and S2 both inside and outside the refrigerator while reducing the overall weight.

[Fifth Embodiment]
FIG. 7 is a side sectional view showing an example of a glass door for a freezing showcase according to a fifth embodiment of the present invention. In the glass door for a freezing showcase according to the fifth embodiment, in addition to forming both the inner glass plate 21 and the central glass plate 31 to be thin by 1 mm, the outer glass plate 12 is also made thin by 1 mm. It differs from the glass door for a freezing showcase according to the fourth embodiment in that it is formed. In the glass door for a refrigerating showcase according to the fifth embodiment, the outer glass plate 12 is thinly configured by using chemically strengthened glass for the outer glass plate 12 as well. As described above, by using the chemically strengthened glass, the outer glass plate 12 can be made thin, and the weight of the entire glass door can be further reduced.

In the glass door for the refrigerating showcase according to the fifth embodiment, the distance d4 between the inner glass plate 21 and the central glass plate 31 is set to 10 mm, whereas the outer glass plate 12 The distance d3 between the central glass plate 31 and the center glass plate 31 is set to 12 mm, and both are set to be unbalanced. Further, the distance d1 between the outer surface of the outer glass plate 12 and the center line 31C in the thickness direction of the central glass plate 31 is 1 + 12 + 0.5 = 13.5 mm, whereas the inner glass plate 21 is 21. The distance d2 between the outer surface (inner surface of the refrigerator) and the center line 31C in the thickness direction of the central glass plate 31 is 1 + 10 + 0.5 = 11.5 mm, and the distance d1 and the distance d2 are unbalanced. It has become.

Further, since the distance d4 between the inner glass plate 21 and the central glass plate 31 is 10 mm, the hollow layer S1 between the outer glass plate 12 and the central glass plate 31 and the inner glass plate 21 and the central glass By enclosing Kr gas in the hollow layer S2 between the plate 31 and the plate 31, the heat insulating performance of the hollow layer S2 inside the refrigerator can be optimized. Further, since the distance d3 between the outer glass plate and the central glass plate 31 is 12 mm, d4 <d3, and the volume of the hollow layer S2 inside the refrigerator is smaller than that of the hollow layer S1 outside the refrigerator. The volume shrinkage change due to cooling is small, and the heat insulation inside the refrigerator can be effectively improved.

According to the glass door for a refrigerating showcase according to the fifth embodiment, the outer glass plate 11 and the inner glass plate 21 are made of chemically strengthened glass, and the outer glass plate 12, the inner glass plate 21 and the central glass are formed. By making all of the plates 31 thin, it is possible to reduce the weight of the entire glass door and optimize the heat insulating performance of the glass door.

The glass doors for freezing showcases according to the first to fifth embodiments have been described above, but in all the embodiments, one side or both sides of the central glass plates 30 and 31, that is, at least one of them is necessary. The surface may be coated with a low radiation Low-E coating. As a result, the heat insulating performance of the glass door for the freezing showcase can be further improved.

Further, the glass door for the refrigerating showcase according to the third embodiment using laminated glass can be combined with the glass door for the refrigerating showcase according to the first, second and fourth embodiments. The outer glass plate 10 of the second and fourth embodiments may be made of laminated glass 11.

Further, the plate thickness and the installation position of each of the glasses 10, 11, 12, 20, 21, 30, and 31 described in the first to fifth embodiments are merely examples, and can be variously changed according to the application. Needless to say.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions are made to the above-mentioned embodiments without departing from the scope of the present invention. Can be added.

This international application claims priority based on Japanese Patent Application No. 2015-134497 filed on July 6, 2015, and the entire contents of Japanese Patent Application No. 2015-134497 are incorporated into this international application. do.

10, 11, 12 Glass plate on the outside of the cabinet 20, 21 Glass plate on the inside of the cabinet 30, 31 Central glass plate 40, 41 Spacer 50 to 52 Door stile 60, 61 Code heater 70 Magnet gasket 80 to 82 Frame frame

Claims (5)

A glass door for a freezing showcase
A first glass plate arranged on the outside of the freezing showcase,
A second glass plate arranged inside the freezing showcase,
It has a first glass plate and a third glass plate arranged apart from the second glass plate between the first glass plate and the second glass plate.
The first distance between the outer surface of the first glass plate and the center line in the thickness direction of the third glass plate is the inner surface of the second glass plate and the third. Greater than the second distance between the glass plate and the centerline in the thickness direction.
The third glass plate is thinner than the first glass plate and the second glass plate.
The value (d3 / d4) obtained by dividing the distance d3 between the first glass plate and the third glass plate by the distance d4 between the second glass plate and the third glass plate is 1.1 or higher,
Kr gas is sealed in the first hollow layer between the first glass plate and the third glass plate.
A glass door for a freezing showcase in which the distance d3 between the first glass plate and the third glass plate is 9 to 11 mm. The glass door for a freezing showcase according to claim 1, wherein the thickness of the third glass plate is 0.8 mm or more and 2 mm or less. The glass door for a freezing showcase according to claim 1 or 2, wherein the second hollow layer between the second glass plate and the third glass plate is filled with Kr gas. The glass door for a refrigerating showcase according to any one of claims 1 to 3, wherein the first glass plate is a laminated glass in which a pair of glass plates are joined via an interlayer film made of resin. The glass door for a freezing showcase according to any one of claims 1 to 4, wherein at least one surface of the third glass plate is coated with Low-E.

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