JP7397604B2 - Showcase - Google Patents

Description

TECHNICAL FIELD The present invention relates to a showcase that is equipped with a heat insulating window body having two light-transmissive window panels, and that stores items while displaying them so that they can be viewed from the outside.

2. Description of the Related Art Stores such as grocery stores and convenience stores use showcases to refrigerate or freeze food, beverages, and other items. This showcase has a storage room in which items are displayed inside a box with an insulated structure, and a cooling device (cooling means) equipped with a compressor, condenser, etc. is located below this storage room. There is a machine room where the equipment will be installed. Furthermore, an inlet/outlet for taking articles into and out of the storage chamber is formed in the front part of the box, and a door is provided at this inlet/outlet (see, for example, Patent Document 1).

The door of a typical showcase functions as a window through which articles displayed in a storage room can be viewed from outside the showcase (for example, from the front or above the showcase). In order to improve the heat insulation properties of this window (door), a double-layer heat-insulating window is used, in which a gap is formed between two transparent window panels such as glass panels. In addition to the door, the insulating window can also be used as part of the box (on the side or rear side of the storage room).

Japanese Patent Application Publication No. 2017-124237

In showcases, it is required to be able to accurately confirm the external appearance of items from the outside. However, when equipped with an insulated window, if the temperature of the glass plate on the storage room side decreases as the storage room is cooled by the cooling means, and the air between the window plates is cooled and the dew point decreases, then Water vapor contained in the air becomes dew and adheres to the surface of the window panel on the side of the storage room, which may reduce the visibility of items inside the storage room. In this insulated window, the outer circumference of the gap between the window panels is filled with caulking material to maintain airtightness between the window panels, so it is difficult to wipe away condensation that forms between the window panels. It is. For this reason, a common measure to prevent dew condensation is to install dehumidifying material between window panels.

Incidentally, in recent years, transparent synthetic resins such as acrylic resin, polycarbonate, and polyvinyl chloride are sometimes used as materials for window panels other than glass. These synthetic resins vary greatly in water vapor permeability (ease of permeation of water vapor) depending on their type. Generally, the value of water vapor permeability decreases as the temperature of the synthetic resin decreases. Therefore, when the two panes of an insulated window are made of the same shape and material, when the storage compartment is cooled according to the cooling operation of the cooling means, the temperature of the window pane (synthetic resin board) on the storage compartment side decreases. As a result, the water vapor permeability decreases, and a difference occurs in the water vapor permeability between the two window panels. The amount of water vapor moving from the outside between both window panels (synthetic resin panels) is greater than the amount of water vapor moving from between both window panels to the storage room side, and the water vapor contained in the air between both window panels is The amount increases. In this way, the air between both window panels will contain a lot of water vapor and will be cooled by the window panel on the storage room side, resulting in easy condensation between both window panels (synthetic resin panels). . In contrast, dehumidifying agents are expected to have a dehumidifying effect, but there are limits to their ability. In other words, when the dehumidifier reaches its capacity limit due to continuous cooling operation, the amount of water vapor in the air between the window panels will increase, causing condensation to form between the window panels. cannot be prevented.

Therefore, the present invention has been proposed in order to suitably solve the problems inherent in conventional showcases, and provides a showcase that can suppress dew condensation on a light transmitting plate included in a heat insulating structure. The purpose is to

In order to overcome the above problems and achieve the intended purpose, the first means is to:
The insulation structure includes a storage chamber for storing articles, a cooling means for cooling the storage chamber, and a heat insulation structure configured such that a plurality of light transmitting plates face each other with a gap space in between. In a showcase in which the storage chamber can be viewed from the outside through a transparent plate,
The heat insulating structure includes an inner light transmitting plate located on the storage chamber side of the gap space, and an outer light transmitting plate located on the outside side of the gap space,
During cooling operation by the cooling means, a state may be formed in which the amount of water vapor moving from the gap space through the inner light transmitting plate into the storage chamber is greater than the amount of water vapor moving into the gap space through the outer light transmitting plate. The gist is that this is the case.
According to this configuration , during the cooling operation of the cooling means, that is, the air in the storage chamber is cooled, and the temperature of the inner light transmitting plate becomes lower than the temperature of the outer light transmitting plate due to the influence of the cooled air in the storage chamber. Under certain circumstances, a state may be created in which the amount of water vapor moving from the gap space through the inner light transmitting plate into the storage chamber is greater than the amount of water vapor moving into the gap space through the outer light transmitting plate. The amount of water vapor in the air that exists in the gap space is suppressed. Therefore, it is possible to prevent dew condensation from forming on the surface of the inner light transmitting plate, and to maintain good visibility in the storage chamber. Furthermore, it is possible to reduce the amount or eliminate the need for a dehumidifying material installed in the heat insulating structure.

The second means is
The gist is that the inner light transmitting plate is made of a material having a higher water vapor permeability than the outer light transmitting plate.
According to this configuration , based on the difference in water vapor permeability between the materials of the inner light transmitting plate and the outer light transmitting plate, it is possible to realize a structure that prevents condensation of the heat insulating structure. Note that by using different materials for both light transmitting plates, the physical properties lacking in the material of one light transmitting plate can be compensated for by the other light transmitting plate, and the quality of the heat insulating structure as a whole can be improved.

The third means is
The gist is that the thickness of the inner light transmitting plate is smaller than the thickness of the outer light transmitting plate.
According to this configuration , it is possible to realize a structure that prevents condensation of the heat insulating structure based on the difference in thickness between the inner light transmitting plate and the outer light transmitting plate. Therefore, the degree of freedom in selecting the materials for both light transmitting plates is increased. Further, in the manufacturing stage of the heat insulating structure, mistakes such as attaching the inner light transmitting plate and the outer light transmitting plate in reverse can be reliably prevented.

According to the showcase according to the present invention, dew condensation on the light transmitting plate included in the heat insulating structure can be suppressed.

1 is a front view of a showcase according to Example 1. FIG. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. Note that other than the main parts have been simplified. 3 is an enlarged view of the X section in FIG. 2. FIG. It shows an example of the material of the window board and its relationship with its water vapor permeability. FIG. 2 is an enlarged view of main parts of a showcase according to a second embodiment. FIG. 7 is an enlarged view of main parts of a showcase according to a modified example.

Next, the showcase according to the present invention will be described by giving preferred embodiments and referring to the accompanying drawings. In the following description, "top", "bottom", "left", and "right" are referred to when the showcase is viewed from the front side (front side) as shown in FIG.

(About the overall structure of Showcase 10)
As shown in FIGS. 1 and 2, the showcase 10 includes a vertically long rectangular box 11 having a storage chamber 13 defined therein. Further, a compressor, a condenser, etc. (none of which are shown) constituting a cooling device (cooling means) 15 are housed in the lower part of the box 11 (below the storage chamber 13). Note that during cooling operation by the cooling device 15, an evaporator (not shown) constituting the cooling device 15 is configured to cool the air in the storage chamber 13 to a set temperature (for example, 0 to 2° C.). .

(About door 17)
The box body 11 is provided with a left door 17A and a right door 17B so as to close the entrance 12 formed on the front surface thereof. In addition, since the left door 17A and the right door 17B basically have the same structure, they will be collectively described as "door 17" in the following description. In Embodiment 1, a two-panel door that slides in the left-right direction inside the entrance/exit 12 is used, but a two-panel door with double doors or a single door that opens and closes with one side edge as an axis is used. Good too.

As shown in FIGS. 2 and 3, the door 17 includes a vertically elongated rectangular insulating window (insulating structure) 20, and the outer peripheral end of the insulating window 20 is surrounded by a frame 19. . The heat insulating window 20 basically consists of two transparent (light transmitting) window plates (light transmitting plates) 21 and 22 spaced apart from each other in the front and back, and is arranged along the outer peripheral edges of both window plates 21 and 22. The spacer 25 keeps the relative position (distance in the front-rear direction) of both the window plates 21 and 22 constant. That is, when the showcase 10 is viewed from the front, the majority of the showcase 10 except for the outer peripheral edge of the door 17 is composed of two window panels 21 and 22, and the box body 11 is opened through these window panels 21 and 22. The inside of the storage chamber 13 (the inside of the box body 11) is configured to be visible from the outside.

As shown in FIG. 3, the heat insulating window 20 has improved heat insulating properties by forming a gap space 23 between two window plates 21 and 22. In the following description, for convenience, the window plate (light transmitting plate) located on the storage chamber 13 side of the gap space 23 and whose rear surface faces the storage chamber 13 will be referred to as the "inner window plate 21". A window plate (light transmitting plate) located on the outside of the gap space 23 and whose front surface faces the outside is sometimes referred to as the "outer window plate 22."

The spacer 25 includes a housing frame 27 whose inner peripheral surface (on the gap space 23 side) is formed in a groove shape, and a lid member 29 that closes an opening on the inner peripheral side of the housing frame 27. A dehumidifying material 31 is disposed inside the housing frame 27 to reduce the amount of water vapor (humidity) in the air in the gap space 23 . Note that a plurality of vent holes 29a are formed in the lid member 29 so that air can flow between the gap space 23 and the inside of the spacer 25. Furthermore, a caulking material 33 is filled on the outer peripheral surface side of the spacer 25 so as to fill the gap created between the outer peripheral portion of each window plate 21, 22 and the spacer 25.

Here, in the showcase 10 of the first embodiment, the inner window panel 21 and the outer window panel 22 are made of different materials, so that the amount of water vapor moving from the gap space 23 to the inner side than the amount of water vapor moving into the gap space 23 through the outer window panel 22 is It is configured to increase the amount of water vapor that moves into the storage chamber 13 through the window plate 21, thereby preventing an increase in the amount of water vapor in the air existing in the gap space 23. That is, in the first embodiment, a material having higher water vapor permeability than the material forming the outer window plate 22 is used as the material forming the inner window plate 21. In the first embodiment, the thickness T1 of the inner window panel 21 and the thickness T2 of the outer window panel 22 are the same (for example, 5 mm).

FIG. 4 is an example of the water vapor permeability value of each synthetic resin measured under the same environment (same temperature and same thickness) for multiple types of synthetic resins that can form the window panels 21 and 22 having optical transparency. . That is, in the example shown in FIG. 4, polyvinyl chloride, polyethylene terephthalate, high-density polyethylene, polypropylene, polystyrene, and polycarbonate are selected in descending order of water vapor permeability, and in FIG. 4, polycarbonate has the highest water vapor permeability. There is. On the other hand, in the first embodiment, polyvinyl chloride is used as the material for the outer window panel 22, and polycarbonate is used as the material for the inner window panel 21. That is, the outer window plate 22 is made of a synthetic resin with a relatively low water vapor permeability, and the inner window plate 21 is made of a synthetic resin with a relatively high water vapor permeability.

As shown in FIG. 4, the water vapor permeability of the polycarbonate forming the inner window panel 21 is 170 g/m ² ·24h, and the water vapor permeability of polyvinyl chloride forming the outer window plate 22 (5 g/m ² · 24 hours). Therefore, even if the inner window plate 21 (polycarbonate) is cooled by the cooling operation of the cooling device 15 and its water vapor permeability decreases excessively, its value will be higher than the water vapor permeability of the outer window plate 22 (polyvinyl chloride). maintained at the level. Here, when the cooling operation by the cooling device 15 is started, the amount of water vapor in the air in the storage chamber 13 gradually decreases as the temperature decreases. On the other hand, in the showcase 10 of Example 1, the water vapor permeability of the inner window plate 21 during the cooling operation by the cooling device 15 is higher than the water vapor permeability of the outer window plate 22 during the cooling operation. As a result, during cooling operation (for example, when the inside of the storage chamber 13 reaches the set temperature), the amount of water vapor that moves into the gap space 23 through the outer window plate 22 is reduced from the amount of water vapor that moves from the gap space 23 to the inner window plate 21 into the storage room. The amount of water vapor moving into the space 13 becomes larger, and the structure is such that an increase in the amount of water vapor in the air existing in the gap space 23 can be prevented.

Note that the plate thickness dimensions T1 and T2 of both window plates 21 and 22 may be made different. For example, by making the thickness T1 of the inner window panel 21 made of polycarbonate smaller than the thickness T2 of the outer window panel 22 made of polyvinyl chloride, water vapor permeation of both window panels 21 and 22 can be reduced. The difference in degree becomes larger, and it becomes possible to more reliably prevent the occurrence of dew condensation between the window plates 21 and 22.

[Effect of Example 1]
Next, the operation of the showcase 10 according to the first embodiment will be explained.

In the showcase 10 of the first embodiment, the heat insulating window (insulating structure) 20 has an inner window plate (inner light transmitting plate) 21 located on the storage chamber 13 side of the gap space 23 and an inner window plate (inner light transmitting plate) 21 located on the outside side of the gap space 23. The inner window plate 21 is formed of polycarbonate, which is relatively easy to transmit water vapor, and the outer window plate 22 is made of polyvinyl chloride, which is relatively difficult to transmit water vapor. is formed. For example, in FIG. 4, polyvinyl chloride as the material for the outer window panel 22 has a water vapor permeability of 5 g/m ² 24 h under a specific environment, and polycarbonate as the material for the inner window panel 21 , the water vapor permeability value under a specific environment is 170 g/m ² · 24 h.

Here, in the showcase 10 of the first embodiment, when the cooling operation of the cooling device (cooling means) 15 is started, immediately after the start of the operation, the humidity of the air in the storage chamber 13 is present in the gap space 23 and outside. Since the humidity is not significantly different from the humidity of the air, slight condensation may occur between the inner window panel 21 and the outer window panel 22. However, since the cooling operation is performed with the water vapor permeability of the inner window plate 21 being higher than the water vapor permeability of the outer window plate 22, the temperature inside the storage chamber 13 may drop to the set temperature during the cooling operation. When the cooling state is stable, a state is created in which the amount of water vapor moving from the gap space 23 through the inner window plate 21 into the storage chamber 13 is greater than the amount of water vapor moving into the gap space 23 through the outer window plate 22, The amount of water vapor in the air existing in the gap space 23 between both window plates 21 and 22 can be suppressed. Therefore, when the temperature inside the storage chamber 13 has fallen to the set temperature and the cooling state is stable, condensation does not basically occur between the window panels 21 and 22, and the visibility inside the storage chamber 13 is improved. can be kept. Further, it is possible to reduce the amount or eliminate the need for the desiccant material installed in the heat insulating window 20.

In the first embodiment, the inner window panel 21 of the heat insulating window 20 is made of a material with higher water vapor permeability than the outer window panel 22, and dew condensation occurs based on the difference in water vapor permeability between the materials. A prevention structure has been realized. By making the materials of both window panels 21 and 22 different in this way, the physical properties (impact resistance and heat resistance) that are lacking in the material of one window panel (for example, the polyvinyl chloride forming the outer window panel 22) can be improved by the material of the other window panel. This can be supplemented with a light transmitting plate (inner window plate 21 made of polycarbonate), and the quality of the heat insulating window 20 as a whole can be improved.

Next, the showcase 10 according to the second embodiment will be described below with reference to FIG. 5. Note that configurations that are different from Example 1 will be basically explained, and the same configurations as Example 1 will be given the same reference numerals and detailed description will be omitted.

The showcase 10 of Example 2 is different from Example 1 in the materials and plate thickness dimensions of both window plates (light transmitting plates) 21 and 22 in the heat insulating window 20, and is otherwise the same as Example 1. .

Specifically, in the showcase 10 of Example 2, the thickness dimensions T3 and T4 of both window panels 21 and 22 are different, and the thickness dimension T3 (3 mm in Example 2) of the inner window panel 21 is different from that of the outer window panel. 22 (15 mm in Example 2), the inner window plate 21 is configured to have a higher water vapor permeability than the outer window plate 22. As a result, in the showcase 10 of the second embodiment, during the cooling operation by the cooling device 15, the amount of water vapor that moves into the gap space 23 through the outer window plate 22 is lowered by the amount of water vapor moving from the gap space 23 into the storage chamber 13 through the inner window plate 21. This creates a state in which the amount of water vapor that moves is larger than that of the window panels 21 and 22, thereby preventing dew condensation from occurring between the window panels 21 and 22.

In the second embodiment, the inner window plate (inner light transmitting plate) 21 and the outer window plate (outer light transmitting plate) 22 are both made of the same material, polycarbonate. On the other hand, the materials of both window plates 21 and 22 may be made different. For example, by forming the inner window panel 21 from a material with higher water vapor permeability than the material of the outer window panel 22, both windows can be It becomes possible to prevent dew condensation from occurring between the plates 21 and 22.

[Effect of Example 2]
Next, the operation of the showcase 10 according to the second embodiment will be explained.

In the showcase 10 of the second embodiment, the thickness T3 of the inner window panel 21 of the heat insulating window 20 is smaller than the thickness T4 of the outer window panel 22. In other words, the inner window panel 21 and the outer window panel are made of different materials that do not cause a large difference in water vapor permeability as in Example 1 (where the outer window panel 22 is made of polyvinyl chloride and the inner window panel 21 is made of polycarbonate). 22 as well, a structure that prevents condensation of the heat insulating window 20 can be realized based on the difference in the plate thickness dimensions T3 and T4 of the inner window panel 21 and the outer window panel 22. Therefore, the degree of freedom in selecting the material for both window panels 21 and 22 is increased. In addition, by making the thickness dimensions T3 and T4 of the inner window panel 21 and the outer window panel 22 different, it is possible to prevent mistakes such as attaching the inner window panel 21 and the outer window panel 22 in reverse during the manufacturing stage of the heat insulating window 20. can be prevented.

[Example of change]
The present application is not limited to the configuration of the embodiment described above, and for example, the following configuration can be adopted as appropriate.
(1) In Examples 1 and 2, the outer light transmitting plate (outer window plate) is formed as one synthetic resin plate (made of one type of material), and the inner light transmitting plate (inner window plate) is formed as one sheet. It was formed as a synthetic resin board (from one type of material). On the other hand, at least one of the outer light transmitting plate and the inner light transmitting plate may be constructed by stacking a plurality of synthetic resin plates.
In this case, for example, as shown in FIG. A second synthetic resin plate (or The outer light transmitting plate (outer window plate 22) may be configured by overlapping the outer light transmitting plate (sheet) 22b.
Although not shown, a third synthetic resin plate (or sheet) made of a material with relatively high water vapor permeability (for example, polystyrene) and a first synthetic resin plate with relatively high water vapor permeability are also included. The inner light transmitting plate (inner window plate) is constructed by overlapping a fourth synthetic resin plate (or sheet) made of a material (for example, polycarbonate) with different physical properties to the material forming the inner light transmitting plate. Good too.
(2) In Examples 1 and 2, the inner light transmitting plate (inner window plate) was formed of polycarbonate, but under the same environment it was made of polyvinyl chloride, which is the material of the outer light transmitting plate (outer window plate). Other synthetic resins with high water vapor permeability (eg, polystyrene, etc.) may be used as the inner light transmitting plate.
(3) In Example 1, the outer light transmitting plate (outer window plate) was formed of polyvinyl chloride, but water vapor permeation under the same environment was not observed in polycarbonate, which is the material of the inner light transmitting plate (inner window plate). Other synthetic resins with low strength (eg, polyethylene terephthalate, high density polyethylene, polypropylene, etc.) or glass may be employed as the outer light transmitting plate.
(4) In Embodiment 1, a heat insulating structure (insulating window) is provided on the door that opens and closes the entrance formed on the front of the box in the showcase. The structure described in Examples 1 and 2 can also be used for doors provided in showcases that open and close the entrances formed on the rear and top surfaces of the box body, such as showcases for storing and displaying ice cream. A heat insulating structure (insulated window) may be employed.

13 Storage room, 15 Cooling device (cooling means), 20 Insulating window (insulating structure),
21 Inner window plate (light transmitting plate, inner light transmitting plate), 22 Outer window plate (light transmitting plate, outer light transmitting plate),
23 Gap space

Claims (3)

A storage chamber (13) for storing articles, a cooling means (15) for cooling the storage chamber (13), and a plurality of light transmitting plates (21, 22) are configured to face each other with a gap space (23) in between. A showcase comprising a heat insulating structure (20) with a heat insulating structure (20), the interior of the storage chamber (13) being visible from the outside through a plurality of light transmitting plates (21, 22) of the heat insulating structure (20),
The heat insulating structure (20) includes an inner light transmitting plate (21) located on the storage chamber (13) side of the gap space (23), and an outer light transmitting plate (21) located on the outside side of the gap space (23). comprising a plate (22);
The inner light transmitting plate (21) and the outer light transmitting plate (22) are formed of a synthetic resin material, and the synthetic resin material forming the inner light transmitting plate (21) is similar to the outer light transmitting plate (21). 22) is made of a material that has a higher water vapor permeability measured under the same environment than the synthetic resin material that forms it.
During cooling operation by the cooling means (15), the amount of water vapor moving from the gap space (23) through the inner light transmitting plate (21) is greater than the amount of water vapor moving into the gap space (23) through the outer light transmitting plate (22). A state in which a large amount of water vapor moves into the storage chamber (13) can be created.
A showcase featuring this. A storage chamber (13) for storing articles, a cooling means (15) for cooling the storage chamber (13), and a plurality of light transmitting plates (21, 22) are configured to face each other with a gap space (23) in between. A showcase comprising a heat insulating structure (20) with a heat insulating structure (20), the interior of the storage chamber (13) being visible from the outside through a plurality of light transmitting plates (21, 22) of the heat insulating structure (20),
The heat insulating structure (20) includes an inner light transmitting plate (21) located on the storage chamber (13) side of the gap space (23), and an outer light transmitting plate (21) located on the outside side of the gap space (23). comprising a plate (22);
The inner light transmitting plate (21) and the outer light transmitting plate (22) are made of a synthetic resin material, and the inner light transmitting plate (21) and the outer light transmitting plate (22) are made of synthetic resin. The material is made of a material with the same water vapor permeability measured under the same environment, or the synthetic resin material forming the inner light transmitting plate (21) is the same as the synthetic resin material forming the outer light transmitting plate (22). In comparison, it is made of a material with high water vapor permeability measured under the same environment,
The thickness (T3) of the inner light transmitting plate (21) is smaller than the thickness (T4) of the outer light transmitting plate (22),
During cooling operation by the cooling means (15), the amount of water vapor moving from the gap space (23) through the inner light transmitting plate (21) is greater than the amount of water vapor moving into the gap space (23) through the outer light transmitting plate (22). A state in which a large amount of water vapor moves into the storage chamber (13) can be created.
A showcase featuring this. The showcase according to claim 1 or 2, wherein at least one of the inner light transmitting plate (21) and the outer light transmitting plate (22) is formed by stacking a plurality of synthetic resin plates .

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