JP7186549B2 - refrigerated showcase - Google Patents

Description

The technology disclosed in this specification relates to a refrigerated showcase.

In Patent Document 1, a transparent glass plate having a transparent conductive film which functions as an anti-condensation heater is coated on the entire surface, and a transparent conductive film is arranged along the upper edge and the lower edge of the transparent glass plate and connected to a power supply. A showcase door is disclosed that includes a pair of external connection electrodes that conduct electricity through a film, and a pair of upper and lower frames that hold a transparent glass plate in a manner that covers the external connection electrodes.

JP 2012-13304 A

By the way, the glass door of the refrigeration showcase may be cooled with a predetermined temperature distribution during the cooling operation due to the circulation of cold air inside the refrigerator, the natural convection of air, and the like.

However, in the configuration disclosed in Patent Document 1, in order to suppress dew condensation on the transparent glass plate, the entire surface of the transparent glass plate is uniformly heated. is heated to a temperature that greatly exceeds the dew point temperature, and there is a risk that the electric power related to dew condensation prevention will be wasted.

The technology disclosed in the present specification has been perfected based on the above circumstances, and can reduce the power consumption related to dew condensation prevention without impairing the dew condensation prevention function of the frame and the sheet glass. The purpose is to provide a refrigerated showcase.

In order to solve the above problems, the refrigerated showcase disclosed in the present specification is a refrigerated showcase comprising a glass door for opening and closing an opening of a storage compartment, wherein the glass door includes sheet glass and the A frame holding a peripheral edge of the sheet glass and a cord heater arranged along at least a part of the frame, wherein the frame is arranged adjacent to a first region of the sheet glass. a first portion to which a predetermined amount of heat is transferred from the code heater; and a second portion, which is arranged adjacent to a second region of the sheet glass and to which a smaller amount of heat is transferred from the cord heater than the first portion. , have.

According to such a configuration, the heat of the cord heater is transferred to the frame, and further transferred to the sheet glass via the frame. In the above configuration, the amount of heat transferred from the cord heater to the frame is smaller in the second portion than in the first portion. When the temperature of each surface of the glass is set to the dew point temperature or higher, each of the first and second portions of the frame and each of the first and second regions of the sheet glass are supplied with heat from the cord heater as necessary. Amount of heat can be given. As a result, power consumption for preventing condensation of the frame and sheet glass is reduced compared to the configuration in which the amount of heat transmitted from the cord heater to the frame is the same as that of the first portion over the entire area without impairing the effect of preventing condensation. can be reduced.

In the above configuration, a case body having the storage chamber that opens to the front is provided, the storage chamber is provided with a cold air outlet for cooling the inside of the storage chamber on the back side of the top surface, and the sheet glass is , the first area may be located at the bottom and the second area may be located at the top. According to such a configuration, when the temperature of the first area of the sheet glass that hits the cold air from the outlet at a higher wind speed and a lower temperature than the second area of the sheet glass is the dew point temperature or higher. , the second region (and the second portion of the frame) can be prevented from being heated more than necessary, compared to the configuration in which the frame and the sheet glass are uniformly heated, and the dew condensation on the frame and the sheet glass can be prevented. power consumption can be reduced.

The cord heater includes a first heater wire routed along the first portion and a second heater wire routed along the second portion, and a calorific value of the second heater wire may be configured to be smaller than the amount of heat generated by the first heater wire. With such a configuration, the amount of heat transferred from the cord heater to the second portion of the frame can be preferably made smaller than the amount of heat transferred to the first portion.

The cord heater may include a first cord heater having the first heater wire and a second cord heater having the second heater wire. According to such a configuration, for example, by applying the same voltage to a plurality of code heaters having different resistance values, or by applying different magnitudes of currents to a plurality of code heaters having the same resistance value, Preferably, the amount of heat generated by the second heater wire is smaller than the amount of heat generated by the first heater wire.

In the cord heater, the resistance value of the second heater wire may be smaller than the resistance value of the first heater wire, and the first heater wire and the second heater wire may be connected in series. With such a configuration, the amount of heat generated by the second heater wire is preferably smaller than the amount of heat generated by the first heater wire. Further, by connecting the first heater wire and the second heater wire to each other, the total length of the lead wire can be shortened, and the space required for routing the lead wire can be reduced.

The code heater may be a variable resistance code heater in which the first heater wire and the second heater wire having a resistance value smaller than that of the first heater wire are integrated. With such a configuration, there is no need to separately connect the first heater wire and the second heater wire, and the cord heater can be easily assembled.

The cord heater may be configured such that the amount of heat generated decreases from the first heater wire toward the second heater wire. According to such a configuration, the amount of heat transferred from the cord heater can be gradually reduced from the first portion toward the second portion of the frame. As a result, the frame and the sheet glass can be heated according to the temperature gradient, and the power consumption related to the dew condensation prevention of the frame and the sheet glass can be suitably reduced.

The cord heater may be configured such that a heater wire is routed along the first portion and is not routed along the second portion. According to such a configuration, the total length of the heater wire can be shortened compared to the configuration in which the heater wire is routed over the entire frame, and the unit cost of the parts related to the cord heater can be reduced. Furthermore, since the heater wire is shortened, the cord heater can be easily handled, and the cord heater can be assembled easily.

The frame includes an upper frame portion that holds an upper edge portion of the sheet glass, a pair of side frame portions that hold both side edge portions of the sheet glass, and a lower edge portion of the sheet glass. a lower frame portion, wherein the first portion is a lower portion positioned relatively lower between the lower frame portion and the pair of side frame portions, and the second portion is a pair of The upper portion of the side frame portion positioned relatively upward may be the upper frame portion. According to such a configuration, the upper portion of the frame, which tends to have a higher temperature than the lower portion of the frame due to natural convection of air inside the frame and circulation of cool air in the refrigerator, is used as the second portion. Avoid heating more than necessary. In addition, in the pair of side frame portions of the frame, the dimensions of the lower portion and the upper portion are appropriately set according to, for example, the amount of heat generated by the glass heater, the cooling characteristics of the refrigerated showcase, and the like. can be heated accordingly. As a result, it is possible to suitably reduce the power consumption related to the dew condensation prevention of the frame and the sheet glass.

The frame includes an upper frame portion that holds an upper edge portion of the sheet glass, a pair of side frame portions that hold both side edge portions of the sheet glass, and a lower edge portion of the sheet glass. and a lower frame portion, wherein the first portion is the lower frame portion, and the second portion is the pair of side frame portions and the upper frame portion. According to such a configuration, the pair of side frame portions and the upper frame portion, whose temperature tends to be higher than the lower frame portion of the frame due to the natural convection of the air inside the frame and the circulation of cold air in the refrigerator, are placed in the second position. By using two parts, the pair of side frame parts and the upper frame part can be prevented from being heated more than necessary, and the power consumption related to the dew condensation prevention of the frame and the sheet glass can be suitably reduced. In addition, by wiring the heater wire only in the lower frame portion which is particularly easily cooled in the frame and is difficult to be heated by the heat transfer due to the natural convection of the air inside the frame, the effect of preventing dew condensation on the frame and sheet glass is impaired. Therefore, the total length of the heater wire can be shortened, and the cord heater can be easily handled.

The frame includes an upper frame portion that holds an upper edge portion of the sheet glass, a pair of side frame portions that hold both side edge portions of the sheet glass, and a lower edge portion of the sheet glass. and a lower frame portion, wherein the first portion is the lower frame portion and the pair of side frame portions, and the second portion is the upper frame portion. According to this configuration, the upper frame portion, which tends to have a higher temperature than the lower frame portion and the pair of side frame portions, is placed first due to natural convection of air inside the frame and circulation of cold air in the refrigerator. By using two parts, the upper frame part can be prevented from being heated more than necessary, and the power consumption related to the prevention of dew condensation on the frame and the sheet glass can be suitably reduced.

A glass heater made of a transparent conductive film formed on a glass surface of the sheet glass is further provided, and the glass heater is energized only to the glass heater and not to the cord heater during cooling operation. The amount of heat generated may be set such that the temperature of the outer surface of the first region of the sheet glass is lower than the dew point temperature. According to such a configuration, compared to a configuration in which the temperature of the outer surface of the entire sheet glass is equal to or higher than the dew point temperature only by the amount of heat generated by the glass heater, by adopting a glass heater with low power consumption, It is possible to reduce the power consumption related to the dew condensation prevention of the sheet glass. By compensating for the shortage of the amount of heat generated by the glass heater with the amount of heat transferred from the cord heater to the sheet glass through the frame, dew condensation on the sheet glass can be suppressed.

A glass heater made of a transparent conductive film formed on a glass surface of the sheet glass is further provided, wherein the glass heater is such that the amount of heat generated in the first region of the sheet glass is greater than that of the second region of the sheet glass. It may be configured to be smaller than the amount of heat generated. According to such a configuration, the amount of heat generated by the glass heater can be reduced compared to, for example, a configuration in which the entire area of the glass heater has the same amount of heat as that of the second region. Power consumption can be reduced. Then, dew condensation in the first area of the sheet glass is suppressed by compensating for the shortage of the amount of heat generated by the glass heater in the first area with the amount of heat transferred from the cord heater to the first area through the first portion of the frame. can do.

In the above configuration, a case body having the storage chamber that opens to the front is provided, the storage chamber is provided with a cold air outlet for cooling the inside of the storage chamber on the back side of the top surface, and the sheet glass is , the first area may be located on the top and the second area may be located on the bottom. According to such a configuration, in the second area of the sheet glass, the cool air from the blow outlet hits at a higher wind speed and a lower temperature than the first area of the sheet glass, and is arranged in the second area. The first region of the sheet glass, which is more difficult to cool than the second region, can be heated appropriately by the cord heater, which is a more localized heating mode than the glass heater. . For this reason, compared to a configuration in which the sheet glass is uniformly heated by both the glass heater and the cord heater, the first region can be prevented from being heated more than necessary, and the dew condensation prevention of the sheet glass can be prevented. Power consumption can be reduced.

The glass heater is provided with a pair of electrodes at positions facing each other on the peripheral end portion of the transparent conductive film, and the pair of electrodes are arranged at positions corresponding to the second region of the sheet glass. In addition, it may be configured not to be arranged at a position corresponding to the first region of the sheet glass. According to such a configuration, it is possible to suitably realize a glass heater in which the amount of heat generated in the first region of the sheet glass is smaller than the amount of heat generated in the second region. For the first region of the sheet glass where the pair of electrodes is not arranged, dew condensation in the first region is suppressed by setting the amount of heat generated by the cord heater so that the temperature of the first region is equal to or higher than the dew point. It is possible.

The sheet glass may be double glazing in which a pair of glasses are laminated via a heat insulating layer. According to such a configuration, compared with a configuration in which the sheet glass is a single layer glass, the surface of the sheet glass on the outer side of the storage is less likely to be cooled by the cold air in the storage chamber, and dew condensation on the sheet glass is further reduced. Power consumption related to prevention can be reduced. In addition, when the plate glass is arranged with the glass surface aligned vertically, the temperature of the upper portion of the sheet glass tends to be higher than that of the lower portion due to the natural convection of the air between the pair of glasses. A necessary amount of heat is applied from the cord heater to each of the first region and the second region of the sheet glass so that the upper portion is not heated more than necessary, thereby preventing dew condensation on the sheet glass. Power can be reduced.

The frame includes a resin member positioned inside the container and a metal member positioned outside the container when the glass door is closed. It may have a support wall portion that supports the outer side of the chamber in the portion, and a locking portion that locks the cord heater. According to such a configuration, the heat from the cord heater can be easily transmitted to the outside surface of the sheet glass via the metal member, and the sheet glass can be efficiently heated by the cord heater.

According to the technology disclosed in this specification, it is possible to provide a refrigerated showcase capable of reducing the power consumption related to the dew condensation prevention of the frame and the sheet glass without impairing the dew condensation prevention effect.

Front view of a refrigerated showcase according to Embodiment 1 Cross section of refrigerated showcase Partial cross-sectional view of the glass door (corresponding to the view cut along the III-III line in Fig. 1) Schematic diagram showing the configuration of the glass heater and cord heater Schematic diagram schematically showing the configuration of a glass heater and a cord heater according to Embodiment 2. Schematic diagram schematically showing the configuration of a glass heater and a cord heater according to Embodiment 3 Graph showing the resistance value of the cord heater Schematic diagram schematically showing the configuration of a glass heater and a cord heater according to Embodiment 4 Graph showing the resistance value of the cord heater The schematic diagram which shows typically the structure of the glass heater which concerns on Embodiment 5, and a cord heater. Schematic diagram schematically showing the configuration of a glass heater and a cord heater according to Embodiment 6. Schematic diagram schematically showing the configuration of a glass heater and a cord heater according to Embodiment 7 Schematic diagram schematically showing the configuration of a glass heater and a cord heater according to Embodiment 8 Schematic diagram schematically showing the configuration of a glass heater and a cord heater according to Embodiment 9

<Embodiment 1>
Embodiment 1 will be described with reference to FIGS. 1 to 4. FIG. In this embodiment, a two-door refrigerated showcase 10 is illustrated. In the following description, the left-right direction in FIG. 1 is the horizontal direction, the up-down direction is the vertical direction, the left side of FIG. 2 is the front side, and the right side is the rear side.

As shown in FIGS. 1 and 2, the refrigerated showcase 10 includes a case body 11 having a storage compartment 12 that opens to the front, and glass doors 40, 40 for opening and closing the opening 13 of the storage compartment 12. I have. The refrigerator showcase 10 allows the inside of the storeroom 12 to be viewed from the front through the glass doors 40 , 40 .

The case main body 11 is formed of a vertically long heat-insulating box body, and has a storage chamber 12 inside. The storage room 12 is equipped with a shelf network 14 for refrigerating and displaying food and beverages over a plurality of stages. The opening 13 of the storage room 12 is partitioned left and right by a partition frame 15, and a pair of glass doors 40, 40 are attached to both sides of the partition frame 15 so as to be openable and closable.

A machine room 20 is provided on the upper surface of the case body 11, and a refrigerating device 21 is installed therein. A refrigerating device 21 includes a compressor 22, a condenser 23 with a condenser fan 24, and the like, and is mounted on a heat-insulating base 25 to form a unit. The base 25 is attached to the case body 11 so as to close the window hole 18 of the ceiling wall 17 of the case body 11 .

The storeroom 12 is provided with a cold air outlet 35 for cooling the inside of the storeroom on the back side of the top surface 17A. Specifically, an air duct 26 that also serves as a drain pan is stretched through the window hole 18 of the ceiling wall 17 of the case body 11, and a cooler chamber 30 is formed above it. The bottom surface of the air duct 26 is formed so as to slope downward toward the innermost edge (right side in FIG. 1). formed.

In the cooler chamber 30, a cooler 31 (evaporator) and an internal fan 33 facing the suction port 32 are installed. The cooler 31 is circulatingly connected to the above-described refrigerating device 21 through refrigerant pipes to form a well-known refrigerating cycle. When the internal fan 33 is driven while operating the refrigerating device 21 (compressor 22), the indoor air in the storage compartment 12 is sucked into the cooler compartment 30 from the suction port 32 by the internal fan 33, and the air is Cold air is generated by heat exchange while flowing through the cooler 31 . The cold air is blown out along the inner surface of the storage chamber 12 from the outlet 35, and the cold air is circulated into the storage chamber 12. - 特許庁In FIG. 2 , the flow of cool air blown out from the outlet 35 is indicated by white arrows.

Next, the glass door 40 will be described with reference to FIGS. 1 to 3. FIG. The pair of glass doors 40, 40 are bilaterally symmetrical to each other. In the following description, the right side glass door 40 will be described, and the left side glass door 40 will be omitted.

The glass door 40 includes a sheet glass 41 , a frame 50 that holds a peripheral edge portion 42 of the sheet glass 41 , and a cord heater 60 arranged along at least a portion of the frame 50 . The glass door 40 includes a glass heater 70 made of a transparent conductive film 71 formed on the glass surface 45A of the sheet glass 41, a handle 48 attached to the frame 50, and a rear side of the frame 50 (case main body 11 side). and an attached door gasket 49 . In the following description, in the installation state of the glass door 40, the lower portion is called the lower portion 40A, and the upper portion is called the upper portion 40B.

The plate glass 41 is a transparent plate-like member having a rectangular shape in plan view, and is installed in a posture in which the longitudinal direction thereof extends along the vertical direction. In this embodiment, the sheet glass 41 is double-layered glass in which a pair of glasses 45 and 46 are laminated with a heat insulating layer 47 interposed therebetween. The heat insulating layer 47 is a layer filled with dry air or the like and having a low thermal conductivity, and is configured such that the glass 45 on the outside of the refrigerator is difficult to be cooled by the cold air inside the refrigerator.

The frame 50 includes an upper frame portion 51 that holds the upper edge of the sheet glass 41 , a pair of side frame portions 52 that hold both side edges of the sheet glass 41 , and a lower edge of the sheet glass 41 . and a lower frame portion 53 that holds the portion. The upper frame portion 51, the pair of side frame portions 52, and the lower frame portion 53 are assembled together to form a rectangular frame shape. The frame 50 has a substantially U-shaped cross section that can accommodate the peripheral portion 42 of the sheet glass 41, and has a hollow structure containing an air layer inside for the purpose of reducing heat conduction. When the glass door 40 is closed, the frame 50 includes a resin member 55 positioned relatively inside the container and a metal member 56 positioned relatively outside the container. The resin member 55 is made of a resin material such as polypropylene, and the metal member 56 is made of a metal material such as aluminum.

The metal member 56 includes a support wall portion 57 that supports the outer surface 43 of the peripheral edge portion 42 of the sheet glass 41 and an outer peripheral wall portion 58 that extends from the outer peripheral end portion of the support wall portion 57 toward the inner side of the storage. and an engaging portion 59 provided on the inner surface of the outer peripheral wall portion 58 to engage the cord heater 60 . The support wall portion 57 has a frame shape extending along the outside surface 43 of the sheet glass 41 and contacts the outside surface 43 of the peripheral portion 42 via a plate-like resin member 55 . be done. The engaging portion 59 has a groove shape surrounding three sides of the outer peripheral surface of the cord heater 60, and the cord heater 60 is assembled therein.

Next, a configuration for preventing dew condensation on the glass door 40 will be described with reference to FIG.
The frame 50 is arranged adjacent to the first region 41A of the sheet glass 41 and arranged adjacent to the first portion 50A to which a predetermined amount of heat is transferred from the cord heater 60 and the second region 41B of the sheet glass 41. and a second portion 50B to which the code heater 60 transmits less heat than the first portion 50A. In the present embodiment, in the second portion 50B, the amount of heat generated by the heater wire routed in the first portion 50A is higher than that of the heater wire routed in the first portion 50A. A configuration in which the amount of heat generated by the heated heater wire is small will be exemplified.

The sheet glass 41 has a first region 41A located in the lower portion 40A and a second region 41B located in the upper portion 40B. Specifically, the first region 41A is a portion that occupies approximately the lower half of the sheet glass 41 , and the second region 41B is a portion that approximately occupies the upper half of the sheet glass 41 . This "first area" is more likely to be cooled than the "second area" due to the effects of cool air inside the refrigerator and the natural convection of the air in the pair of glasses 45 and 46 and the air in the frame 50. area. The first portion 50A of the frame 50 is located around the first area 41A of the sheet glass 41, and the second portion 50B is located around the second area 41B of the sheet glass 41. As shown in FIG. Specifically, the first portion 50A is the lower portion 52A of the lower frame portion 53 and the pair of side frame portions 52, 52 positioned relatively on the lower side, and the second portion 50B is the pair of side frame portions. An upper portion 52B and an upper frame portion 51 are positioned relatively upward in the portions 52 and 52 . In addition, in FIG. 4, the frame 50 is drawn with a two-dot chain line.

The cord heater 60 includes a first heater wire 60A routed along the first portion 50A and a second heater wire 60B routed along the second portion 50B. The first heater wire 60A is arranged in a U shape along the first portion 50A, and the second heater wire 60B is arranged in an inverted U shape along the second portion 50B.

The cord heater 60 includes a first cord heater 61 having a first heater wire 60A and a second cord heater 62 having a second heater wire 60B. Lead wires 65 are connected to both ends of the first heater wire 60A of the first cord heater 61, and the first heater wire 60A is connected to an external power source via the lead wires 65A. In the second cord heater 62, lead wires 65 are connected to both ends of the second heater wire 60B, and the second heater wire 60B is connected to an external power supply via the lead wires 65. As shown in FIG. The cord heater 60 has a first heater wire 60A and a second heater wire 60B each attached to a locking portion 59 of the frame 50, and a lead wire 65 extending from the frame 50 to the outside.

The cord heater 60 is configured such that the amount of heat generated by the second heater wire 60B is smaller than the amount of heat generated by the first heater wire 60A. Here, the amount of heat generated is inversely proportional to the resistance value for the same voltage value. For this reason, for example, when the first cord heater 61 and the second cord heater 62 are connected in parallel and the same voltage is applied to both, the cord heater 60 has the resistance value of the second heater wire 60B, for example. is greater than the resistance value of the first heater wire 60A. In the description of the present application, the resistance value of the heater wire refers to the resistance value per unit length of the heater wire. The configuration in which the first heater wire 60A and the second heater wire 60B have different heat generation amounts is not limited to this. Alternatively, the voltage applied to the second heater wire 60B may be smaller than the voltage applied to the first heater wire 60A. Alternatively, the energization rate of the second heater wire 60B may be made lower than the energization rate of the first heater wire 60A so that the amount of heat generated by the second heater wire 60B is smaller than the amount of heat generated by the first heater wire 60A. .

The glass heater 70 is provided on the inner glass surface 45A of the glass 45 positioned on the outer side of the double-glazed glass (see FIG. 3). The transparent conductive film 71 is formed over substantially the entire area of the glass surface 45A. A pair of electrodes 73 , 73 are provided on the glass heater 70 at positions facing each other on the peripheral edge of the transparent conductive film 71 . The transparent conductive film 71 is, for example, a thin film of metal oxide such as tin oxide, and is uniformly coated on the glass surface 45A. The pair of electrodes 73, 73 are formed in a longitudinal shape by baking silver paste, for example, and are formed over the entire length of the transparent conductive film 71 in the vertical direction. The pair of electrodes 73, 73 are connected to a lead wire (not shown) and connected to an external power source via the lead wire. With such a configuration, the glass heater 70 generates a uniform amount of heat on the glass surface 45</b>A of the sheet glass 41 . In FIG. 4, the region of the sheet glass 41 heated by the glass heater 70 is shaded.

Next, the operation of the refrigerated showcase 10 during the cooling operation will be described. When the refrigerating showcase 10 is operated for cooling, as shown in FIG. flow toward For this reason, the first area 41A of the sheet glass 41 of the glass door 40 is exposed to cold air at a higher wind speed and a lower temperature than other areas. Further, due to the natural convection of the air inside the frame 50 and the natural convection of the air in the heat insulating layer 47, the upper portion 40B of the glass door 40 becomes a relatively high temperature region, and the lower portion 40A becomes a relatively low temperature region. Then, the surface temperature of the surface 43 of the sheet glass 41 on the outer side of the refrigerator becomes lower in the first region 41A than in the second region 41B. The thermal conductivity of the sheet glass 41 is lower than the thermal conductivity of the metal material forming the metal member 56 of the frame 50, and the temperature gradient between the first region 41A and the second region 41B in the sheet glass 41 is considered difficult to resolve. Therefore, the amount of heat required to bring the outside surface 43 of the glass 45 to a temperature equal to or higher than the dew point temperature is greater in the first region 41A of the sheet glass 41 than in the second region 41B. If the glass heater 70 and the cord heater 60 are not energized, the sheet glass 41 is cooled by the cold air inside the refrigerator, and the outer surface 43 of the refrigerator is below the dew point temperature. As a result, dew condensation occurs on the outer surface 43 of the sheet glass 41, which reduces the visibility of the glass door 40, and there is concern that the dew condensation water may drip onto the floor.

When the glass heater 70 is energized, current flows between the pair of electrodes 73, 73, the transparent conductive film 71 generates heat, and the glass surface 45A of the sheet glass 41 is uniformly heated. When the cord heater 60 is energized, the first heater wire 60A and the second heater wire 60B generate heat in such a manner that the amount of heat generated by the second heater wire 60B is smaller than that of the first heater wire 60A. The heat from the first heater wire 60A and the second heater wire 60B of the cord heater 60 attached to the locking portion 59 is conducted to the metal member 56 of the frame 50, and the outer surface of the frame 50 reaches a temperature equal to or higher than the dew point temperature. The frame 50 is heated as follows. Furthermore, the heat from the first heater wire 60A and the second heater wire 60B of the cord heater 60 is mainly conducted to the peripheral edge portion 42 of the glass 45 via the support wall portion 57 of the frame 50. As shown in FIG. The outside surface 43 of the glass 45 is heated to a dew point temperature or higher by the heat from the glass heater 70 and the heat from the cord heater 60 transmitted through the frame 50 . At this time, the amount of heat transferred from the second heater wire 60B to the second portion 50B of the frame 50 is smaller than the amount of heat transferred from the first heater wire 60A of the cord heater 60 to the first portion 50A of the frame 50. The amount of heat transferred from the second portion 50B to the second region 41B is smaller than the amount of heat transferred from the portion 50A to the first region 41A. Therefore, the cooperation of the glass heater 70 and the cord heater 60 prevents the second region 41B, which is difficult to be cooled by the cold air in the refrigerator, from being heated to a temperature significantly higher than the dew point temperature, and is easily cooled by the cold air in the refrigerator. 41 A of 1st area|regions can be heated more than dew point temperature. As a result, the power consumption of the cord heater 60 can be suppressed and the occurrence of dew condensation on the sheet glass 41 can be suppressed as compared with the configuration in which the amount of heat transferred from the cord heater 60 to the frame 50 is uniform in each part. can be done.

Next, the effects of this embodiment will be described. According to this embodiment, the heat of the cord heater 60 is transferred to the frame 50 and further transferred to the sheet glass 41 via the frame 50 . In the above configuration, the amount of heat transferred from the cord heater 60 to the frame 50 is smaller in the second portion 50B than in the first portion 50A. When the temperature of each surface of the frame 50 and the sheet glass 41 is set to the dew point temperature or higher, each of the first portion 50A and the second portion 50B of the frame 50, and further the first region 41A and the second portion of the sheet glass 41 A necessary amount of heat can be applied from the cord heater 60 to each of the regions 41B. As a result, the amount of heat transmitted from the cord heater 60 to the frame 50 from the cord heater 60 to the frame 50 is the same as that of the first portion 50A over the entire area without impairing the dew condensation prevention effect. Power consumption related to prevention can be reduced.

Further, in this embodiment, the case body 11 is provided with a storage chamber 12 that opens to the front, and the storage chamber 12 is provided with a cold air outlet 35 for cooling the inside of the storage chamber on the back side of the top surface 17A. , the plate glass 41 has the first region 41A positioned at the lower portion 40A and the second region 41B positioned at the upper portion 40B. According to such a configuration, the cold air from the outlet 35 hits the first region 41A of the sheet glass 41 at a higher wind speed and a lower temperature than the second region 41B of the sheet glass 41. In the above case, it is possible to prevent the second region 41B (and the second portion 50B of the frame 50) from being heated more than necessary compared to the configuration in which the frame 50 and the sheet glass 41 are uniformly heated. It is possible to reduce power consumption related to preventing dew condensation on the frame 50 and the sheet glass 41 .

Further, the cord heater 60 includes a first heater wire 60A routed along the first portion 50A and a second heater wire 60B routed along the second portion 50B. The heating value of 60B is configured to be smaller than the heating value of the first heater wire 60A. With such a configuration, the amount of heat transferred from the cord heater 60 to the second portion 50B of the frame 50 can be preferably smaller than the amount of heat transferred to the first portion 50A.

In addition, in the present embodiment, the cord heater 60 includes a first cord heater 61 having a first heater wire 60A and a second cord heater 62 having a second heater wire 60B. According to such a configuration, for example, the same voltage is applied to a plurality of code heaters having different resistance values, different currents are applied to a plurality of code heaters having the same resistance value, and the second By setting the energization rate (voltage application time) to the heater wire 60B lower than the energization rate to the first heater wire 60A, the amount of heat generated by the second heater wire 60B is smaller than the amount of heat generated by the first heater wire 60A. can be

Further, in the present embodiment, the frame 50 includes an upper frame portion 51 that holds the upper edge portion of the sheet glass 41, a pair of side frame portions 52, 52 that respectively hold both side edge portions of the sheet glass 41, and a lower frame portion 53 that holds the lower edge portion of the sheet glass 41 . The second portion 50B is the upper portion 52B, 52B of the pair of side frame portions 52, 52 and the upper frame portion 51, which are positioned relatively upward. With such a configuration, the upper portion of the frame 50, which tends to have a higher temperature than the lower portion of the frame 50 due to the natural convection of the air inside the frame 50 and the circulation of cool air in the refrigerator, is used as the second portion 50B. , the upper portion of the frame 50 can be prevented from being heated more than necessary. In addition, in the pair of side frame portions 52, 52 of the frame 50, the dimensions of the lower portion 52A and the upper portion 52B are adjusted to, for example, the amount of heat generated by the glass heater 70 and the cooling characteristics of the refrigerated showcase (the temperature inside the refrigerator and the amount of cool air). By appropriately setting the circulation path, etc., the sheet glass 41 can be heated as necessary. As a result, power consumption related to prevention of dew condensation on the frame 50 and the sheet glass 41 can be suitably reduced.

Further, in the present embodiment, the sheet glass 41 is a multi-layer glass in which a pair of glasses 45 and 46 are laminated with a heat insulating layer 47 interposed therebetween. According to such a configuration, compared to a configuration in which the sheet glass 41 is a single layer glass, the surface 43 of the sheet glass 41 on the outer side of the storage is less likely to be cooled by the cold air in the storage chamber 12, further Power consumption related to prevention of dew condensation on the sheet glass 41 can be reduced. Further, when the glass surface 45A is disposed in a posture along the vertical direction, natural convection of air between the pair of glasses 45 and 46 causes the upper portion 40B of the sheet glass 41 to be more dense than the lower portion 40A. Although the temperature tends to rise, the cord heater 60 applies a necessary amount of heat to each of the first region 41A and the second region 41B of the sheet glass 41 so that the upper portion 40B is not heated more than necessary. , and the power consumption related to the prevention of dew condensation on the sheet glass 41 can be reduced.

In this embodiment, the frame 50 includes a resin member 55 located inside the refrigerator and a metal member 56 located outside the refrigerator when the glass door 40 is closed. has a support wall portion 57 that supports the outside surface 43 of the peripheral edge portion 42 of the sheet glass 41 and a locking portion 59 that locks the cord heater 60 . According to such a configuration, the heat from the cord heater 60 is easily transmitted to the outer surface 43 of the sheet glass 41 via the metal member 56, and the sheet glass 41 can be efficiently heated by the cord heater 60. can.

<Embodiment 2>
Next, Embodiment 2 will be described with reference to FIG. In this embodiment, a glass door 140 having a cord heater configuration different from that in the above embodiment will be exemplified. In addition, the same code|symbol is attached|subjected to the same part as the said embodiment, and the overlapping description is abbreviate|omitted.

In the cord heater 160, the resistance value of the second heater wire 160B is smaller than the resistance value of the first heater wire 160A, and the first heater wire 160A and the second heater wire 160B are connected in series. Here, the amount of heat generated is proportional to the resistance value when the current value is the same. Therefore, such a cord heater 160 has a configuration in which the amount of heat generated by the second heater wire 160B is smaller than the amount of heat generated by the first heater wire 160A. Specifically, in the cord heater 160, one end of the first heater wire 160A and one end of the second heater wire 160B are connected via a connection portion 167. As shown in FIG. Lead wires 65, 65 are connected to the other ends of the first heater wire 160A and the second heater wire 160B, and the first heater wire 160A and the second heater wire 160B are connected to the outside via the lead wires 65, 65. power supply. The connection portion 167 is configured by crimping the first heater wire 160A and the second heater wire 160B using, for example, a crimping sleeve with an insulation coating, and covering them with an insulator.

According to this embodiment, the amount of heat generated by the second heater wire 160B can be preferably smaller than the amount of heat generated by the first heater wire 160A. Further, by connecting the first heater wire 160A and the second heater wire 160B to each other, the total length of the lead wire 65 can be shortened, and the space required for routing the lead wire 65 can be reduced.

<Embodiment 3>
Next, Embodiment 3 will be described with reference to FIGS. 6 and 7. FIG. In this embodiment, a glass door 240 having a cord heater configuration different from that in the above embodiment will be exemplified. In addition, the same code|symbol is attached|subjected to the same part as the said embodiment, and the overlapping description is abbreviate|omitted.

The cord heater 260 is a variable resistance cord heater in which a first heater wire 260A and a second heater wire 260B having a lower resistance value than the first heater wire 260A are integrated. Specifically, as shown in FIG. 7, the cord heater 260 has a configuration in which the resistance value of the range B constituting the second heater wire 260B is smaller than the resistance value of the range A constituting the first heater wire 260A. It is said that Then, the range A forming the first heater wire 260A is routed along the first portion 50A of the frame 50, and the range B forming the second heater wire 260B is routed along the second portion 50B of the frame 50. It is assumed that

According to this embodiment, there is no need to separately connect the first heater wire 260A and the second heater wire 260B, and the cord heater 260 can be easily assembled.

<Embodiment 4>
Next, Embodiment 4 will be described with reference to FIGS. 8 and 9. FIG. In this embodiment, a glass door 340 having a cord heater configuration different from that in the above embodiment will be exemplified. In addition, the same code|symbol is attached|subjected to the same part as the said embodiment, and the overlapping description is abbreviate|omitted.

The cord heater 360 is configured such that the amount of heat generated decreases from the first heater wire 360A toward the second heater wire 360B. The cord heater 360 is, for example, a variable resistance cord heater, and as shown in FIG. The resistance value of the corresponding range D is smaller than that of the corresponding range D, and the resistance values of the ranges B and C and the ranges E and F corresponding to the pair of side frame portions 52 and 52 change continuously. Then, the ranges C, D, and E constituting the first heater wire 360A are routed along the first portion 50A of the frame 50, and the ranges A, B, and F constituting the second heater wire 360B are arranged along the first portion 50A of the frame 50. It is supposed to be routed along the two parts 50B.

According to this embodiment, the amount of heat transmitted from the cord heater 360 can be gradually reduced from the first portion 50A of the frame 50 toward the second portion 50B. As a result, the frame 50 and the sheet glass 41 can be heated according to the temperature gradient, and the power consumption related to the dew condensation prevention of the frame 50 and the sheet glass 41 can be suitably reduced.

<Embodiment 5>
Next, Embodiment 5 will be described with reference to FIG. This embodiment will exemplify a glass door 440 having a cord heater configuration different from that of the above embodiment. In addition, the same code|symbol is attached|subjected to the same part as the said embodiment, and the overlapping description is abbreviate|omitted.

The frame 50 is arranged adjacent to the first region 41A of the sheet glass 41, and is arranged adjacent to the first portion 50A to which a predetermined amount of heat is transmitted from the cord heater 460, and the second region 41B of the sheet glass 41. and a second portion 50B to which the code heater 460 transfers less heat than the first portion 50A. In the present embodiment, in the second portion 50B, a heater wire 460A having a predetermined heat generation amount is arranged in the first portion 50A as a configuration in which "the amount of heat transferred from the cord heater is smaller than that in the first portion". A configuration in which no heater wire is routed to the portion 50B and the amount of heat directly transmitted to the second portion 50B is substantially zero will be exemplified.

The sheet glass 41 has the first region 41A located at the bottom and the second region 41B located at the top. Specifically, the first region 41A is a portion that occupies approximately the lower ⅓ of the sheet glass 41, and the second region 41B occupies approximately the upper ⅔ of the sheet glass 41. considered part. The first portion 50A of the frame 50 is located around the first area 41A of the sheet glass 41, and the second portion 50B is located around the second area 41B of the sheet glass 41. As shown in FIG. Specifically, the first portion 50A is the lower portion 52A of the lower frame portion 53 and the pair of side frame portions 52, 52 positioned relatively on the lower side, and the second portion 50B is the pair of side frame portions. An upper portion 52B and an upper frame portion 51 are positioned relatively upward in the portions 52 and 52 .

The cord heater 460 is configured such that the heater wire 460A is routed along the first portion 50A and is not routed along the second portion 50B. The heater wire 460A is routed in a U-shape along the first portion 50A, and is connected to an external power supply via lead wires 65 connected to both ends thereof. The positions of both ends of the heater wire 460A, that is, the positions of the upper ends of the first portions 50A of the frame 50 can be appropriately set to arbitrary positions of the pair of side frame portions 52. FIG.

According to the present embodiment, the total length of the heater wire 460A can be shortened compared to the configuration in which the heater wire 460A is routed over the entire area of the frame 50, and the unit cost of the parts related to the cord heater 460 can be reduced. can be done. Furthermore, since the heater wire 460A is shortened, the cord heater 460 can be easily handled, and the cord heater 460 can be assembled easily.

Further, according to the present embodiment, the upper portion of the frame 50, which tends to have a higher temperature than the lower portion of the frame 50, due to the natural convection of the air inside the frame 50 and the heat insulating layer 47, the circulation of cold air in the refrigerator, etc., is the second portion. By using 50B, the upper portion of the frame 50 can be prevented from being heated more than necessary. Also, in the pair of side frame portions 52, 52 of the frame 50, the dimensions of the lower portion 52A and the upper portion 52B may be adjusted, for example, by the amount of heat generated by the glass heater 70 or the cooling characteristics of the refrigerated showcase 10 (internal temperature or cool air). The sheet glass 41 can be heated as needed by appropriately setting according to the circulation path of the heat exchanger, etc. As a result, power consumption related to prevention of dew condensation on the frame 50 and the sheet glass 41 can be suitably reduced.

<Embodiment 6>
Next, Embodiment 6 will be described with reference to FIG. This embodiment will exemplify a glass door 540 in which the arrangement of the first portion and the second portion in the frame is different from that of the fifth embodiment. In addition, the same code|symbol is attached|subjected to the same part as the said embodiment, and the overlapping description is abbreviate|omitted.

The frame 50 has a first portion 550A as a lower frame portion 53 and a second portion 550B as a pair of side frame portions 52, 52 and an upper frame portion 51. As shown in FIG. The cord heater 560 has a heater wire 560A arranged linearly along the first portion 550A, and is connected to an external power supply via lead wires 65 connected to both ends thereof.

According to this embodiment, due to natural convection of air inside the frame 50 and circulation of cool air in the refrigerator, the pair of side frame portions 52 and the upper frame portion 52 tend to have a higher temperature than the lower frame portion 53 of the frame 50 . By using the second portion 550B as the portion 51, the pair of the side frame portions 52 and the upper frame portion 51 can be prevented from being heated more than necessary. can be suitably reduced. In addition, by wiring the heater wire 560A only in the lower frame portion 53, which is particularly easily cooled in the frame 50 and has poor heat transfer due to the natural convection of the air inside the frame 50, dew condensation on the frame 50 and the sheet glass 41 can be prevented. The overall length of the heater wire 560A can be shortened without impairing such an effect, and the cord heater 560 can be easily handled.

<Embodiment 7>
Next, Embodiment 7 will be described with reference to FIG. This embodiment will exemplify a glass door 640 in which the arrangement of the first part and the second part in the frame is different from that of the fifth embodiment. In addition, the same code|symbol is attached|subjected to the same part as the said embodiment, and the overlapping description is abbreviate|omitted.

The frame 50 has a first portion 650A as a lower frame portion 53 and a pair of side frame portions 52, 52, and a second portion 650B as an upper frame portion 51. As shown in FIG. The cord heater 660 has a heater wire 660A routed in a U shape along the first portion 650A, and is connected to an external power supply via lead wires 65 connected to both ends thereof.

According to this embodiment, the temperature of the upper frame tends to be higher than that of the lower frame portion 53 and the pair of side frame portions 52 of the frame 50 due to the natural convection of the air inside the frame 50 and the circulation of cold air in the refrigerator. By using the second portion 650B as the portion 51, the upper frame portion 51 can be prevented from being heated more than necessary, and the power consumption related to the prevention of dew condensation on the frame 50 and the sheet glass 41 can be suitably reduced. can.

<Embodiment 8>
Next, Embodiment 8 will be described with reference to FIG. This embodiment will exemplify a glass door 740 having a different configuration of the glass heater from the above embodiment. In addition, the same code|symbol is attached|subjected to the same part as the said embodiment, and the overlapping description is abbreviate|omitted.

During the cooling operation, the glass heater 770 is energized only to the glass heater 770 and not energized to the cord heater 60 so that the temperature of the outside surface 43 of the first region 41A of the sheet glass 41 is lower than the dew point temperature. calorific value is set. For such a heat generation amount, for example, an expected upper limit value of the dew point temperature is determined assuming the use environment of the refrigerated showcase 10, and a predetermined heat generation amount that is below this upper limit value in the first region 41A of the sheet glass 41 is determined. Alternatively, the dew point temperature may be approximately calculated from the outside air temperature or the like, and the heat generation amount may be appropriately set below the dew point temperature. In a refrigerated showcase, the amount of heat generated by the glass heater is generally larger than the amount of heat generated by the cord heater, depending on the size of the area to be heated. In the present embodiment, the amount of heat generated by the glass heater 770, which consumes a large amount of power, is reduced as compared with the conventional art, and the shortage of the amount of heat generated by the glass heater 770 in the first region 41A is removed from the first portion 50A of the frame 50 to the first area. It is configured to be complemented by heat from the cord heater 60 that is transferred to the first region 41A.

In this embodiment, the first region 41A is a portion that occupies approximately the lower 1/4 range of the sheet glass 41, and the second region 41B is a portion that occupies approximately the upper 3/4 range of the sheet glass 41. be done. The first portion 50A of the frame 50 is located around the first area 41A of the sheet glass 41, and the second portion 50B is located around the second area 41B of the sheet glass 41. As shown in FIG.

The cord heater 60 includes a first heater wire 60A routed along the first portion 50A and a second heater wire 60B routed along the second portion 50B. The first heater wire 60A is arranged in a U shape surrounding the first region 41A of the sheet glass 41, and the second heater wire 60B is arranged in an inverted U shape surrounding the second region 41B. The amount of heat generated by the second heater wire 60B is made smaller than the amount of heat generated by the first heater wire 60A.

According to this embodiment, the glass heater 770 that consumes less power than the configuration in which the temperature of the outer surface 43 of the entire sheet glass 41 is made equal to or higher than the dew point temperature only by the amount of heat generated by the glass heater 770 is adopted. As a result, power consumption related to prevention of dew condensation on the sheet glass 41 can be reduced. By making up for the shortage of the amount of heat generated by the glass heater 770 with the amount of heat transferred from the cord heater 60 to the sheet glass 41 through the frame 50, dew condensation on the sheet glass 41 can be suppressed.

<Embodiment 9>
Next, Embodiment 9 will be described with reference to FIG. This embodiment will exemplify a glass door 840 in which the configurations of the glass heater and the cord heater are different from those of the above embodiments. In addition, the same code|symbol is attached|subjected to the same part as the said embodiment, and the overlapping description is abbreviate|omitted.

The glass heater 870 is configured such that the amount of heat generated in the first area 841A of the sheet glass 41 is smaller than the amount of heat generated in the second area 841B of the sheet glass 41 . In the present embodiment, the first region 841A is a region in which the amount of heat transferred from the glass heater 870 is reduced compared to the second region 841B (hereinafter referred to as a non-heated region to distinguish from the first region 841A, which is a heating region). (also referred to as the (low) heating zone). Note that "the amount of heat transmitted from the glass heater 870 is reduced" means that the glass heater 870 is not disposed in the region and the amount of heat directly transmitted from the glass heater 870 is substantially zero. shall also include

In the present embodiment, the sheet glass 41 has the first region 841A located at the top and the second region 841B located at the bottom. Specifically, the first region 841A is a portion that occupies approximately the upper quarter of the sheet glass 41, and the second region 841B is a portion that approximately occupies the lower three-fourths of the sheet glass 41. be done. This "first region" is a region that is less cooled than the "second region" due to the effect of natural convection of the air in the pair of glasses 45 and 46 and the air in the frame 50. As shown in FIG. The first portion 850A of the frame 50 is located around the first area 841A of the sheet glass 41, and the second portion 850B is located around the second area 841B of the sheet glass 41. As shown in FIG. Specifically, the first portion 850A is the upper portion of the upper frame portion 51 and the pair of side frame portions 52, 52 positioned relatively upward, and the second portion 850B is the pair of side frame portions 52, The lower part of 52 and the lower frame part 53 are positioned relatively on the lower side.

The transparent conductive film 71 is formed over the entire glass surface 45A, and a pair of electrodes 873, 873 are provided on both sides in the horizontal direction. The pair of electrodes 873 , 873 are arranged at positions corresponding to the second regions 841 B of the plate glass 41 and are not arranged at positions corresponding to the first regions 841 A of the plate glass 41 . Specifically, the pair of electrodes 873 , 873 are provided so as to extend vertically along the lower portions of the pair of side frame portions 52 . The heating area of the glass heater 870 is determined according to the position of the electrode 873. By appropriately setting the positions of the pair of electrodes 873, 873, the heating area and the non-heating area of the sheet glass 41 are separated. formed.

The cord heater 860 includes a first heater wire 860A routed along the first portion 850A and a second heater wire 860B routed along the second portion 850B. The first heater wire 860A is arranged in an inverted U shape surrounding the first region 841A of the sheet glass 41, and the second heater wire 860B is arranged in a U shape surrounding the second region 841B. In the present embodiment, the first heater wire 860A surrounds a slightly wider range than the first region 841A of the sheet glass 41, and both ends are located on the sides of the second region 841B. The amount of heat generated by the second heater wire 860B is made smaller than the amount of heat generated by the first heater wire 860A. The amount of heat generated by the first heater wire 860A is determined by the temperature of the outside surface 43 of the first region 841A, which is the non-heating region of the glass heater 870, as the dew point when the glass heater 870 having the non-heating region as described above is used. It is appropriately set so as to be equal to or higher than the temperature.

Next, a mode in which the first region 841A of the sheet glass 41 is heated will be described. Heat from the first heater wire 860A of the cord heater 860 is transmitted from the support wall portion 57 of the frame 50 to the upper side portion and the left and right side portions of the first region 841A having a rectangular shape in plan view. is conducted along the temperature gradient of the sheet glass 41 toward the center of the first region 841A. Part of the heat from the heating region of the glass heater 870 located in the second region 841B is transferred to the lower side of the first region 841A, and the heat is extended to the side of the second region 841B. Heat from both ends of the first heater wire 860A is transmitted through the support wall portion 57 of the frame 50 and the second region 841B of the sheet glass 41. As shown in FIG. Heat from the cord heater 860 is less likely to be transferred to the lower long side of the first region 841A than to other side portions, and the portion of the first region 841A slightly below the central portion is heated the most. considered a difficult area. For this reason, the amounts of heat generated by the cord heater 860 and the glass heater 870 are appropriately set so that the hard-to-heat area has a temperature equal to or higher than the dew point temperature. The area of the region 841A is appropriately set.

According to the present embodiment, for example, compared to a configuration in which the entire area of the glass heater has the same amount of heat as that of the second region 841B, the amount of heat generated by the glass heater 870 can be reduced, and dew condensation on the sheet glass 41 can be prevented. power consumption can be reduced. By compensating for the shortage of the amount of heat generated by the glass heater 870 in the first area 841A with the amount of heat transferred from the cord heater 860 to the first area 841A via the first portion 850A of the frame 50, the sheet glass 41 is heated. Dew condensation in the first region 841A can be suppressed.

Further, according to the present embodiment, the sheet glass 41 has the first region 841A positioned at the top and the second region 841B positioned at the bottom. According to such a configuration, in the second area 841B of the sheet glass 41, the cold air from the blow-out port 35 hits the second area 841B of the sheet glass 41 at a higher wind speed and a lower temperature than the first area 841A of the sheet glass 41. In the first region 841A, which can be sufficiently heated by the glass heater 870 disposed in the region 841B and is less cooled than the second region 841B of the sheet glass 41, the heating mode is more localized than the glass heater 870. Some cord heaters 860 can provide moderate heating. For this reason, compared to the configuration in which the sheet glass 41 is uniformly heated by both the glass heater 870 and the cord heater 860, the first region 841A can be prevented from being heated more than necessary, and the sheet glass 41 can be heated. It is possible to reduce the power consumption related to the prevention of dew condensation.

Further, in the present embodiment, the pair of electrodes 873, 873 are arranged at positions corresponding to the second regions 841B of the plate glass 41, and are not arranged at positions corresponding to the first regions 841A of the plate glass 41. It is configured. According to such a configuration, the glass heater 870 in which the amount of heat generated in the first region 841A of the sheet glass 41 is smaller than the amount of heat generated in the second region 841B can be suitably realized.

<Other embodiments>
The present invention is not limited to the embodiments described above and illustrated in the drawings. For example, the following embodiments are also included in the technical scope of the present invention. can be implemented with various changes.
(1) Embodiments 1 to 8 exemplify configurations in which the first region is located below the sheet glass and the second region is located above the sheet glass, and in Embodiment 9, the first region is the sheet glass. , and the second area is located at the bottom, the arrangement of the first area and the second area is not limited to this. For example, the arrangement of the first area and the second area can be appropriately set according to the installation posture of the sheet glass, the cold air circulation path in the storage compartment, and the location where cold air tends to accumulate in the storage compartment. Furthermore, in the sheet glass, the range and shape of the first region and the second region can be changed as appropriate. good.
(2) In the above embodiment, the refrigerated showcase is provided with a glass heater made of a transparent conductive film formed on the glass surface of the sheet glass, but the present invention is not limited to this. The refrigerated showcase may be configured with only a cord heater without a glass heater, depending on the shape, size, and heat insulation performance of the sheet glass, the temperature in the storage chamber, and the like. Also, the arrangement range of the glass heater and the electrical configuration can be changed as appropriate.
(3) In addition to the above embodiments, the configuration for changing the amount of heat transferred from the cord heater between the first and second portions of the frame can be changed as appropriate without departing from the gist of the present invention.
(4) In addition to the above-described embodiments, the configurations of the respective embodiments may be appropriately combined and used. For example, the electrical configurations of the cord heaters of the second to seventh embodiments and the electrical configurations of the glass heaters of the eighth and ninth embodiments may be appropriately combined. Further, in Embodiments 1 to 4, the arrangement of the first portion and the second portion in the frame may be as in Embodiment 6 or Embodiment 7.
(5) In the above embodiment, the sheet glass is made of double-layer glass, but the sheet glass may be made of single-layer glass. Further, in the above-described embodiment, the glass door that can be opened and closed in a double-door manner was exemplified, but the glass door can be opened and closed in a single-sided manner, a sliding manner, and the like. There may be.
(6) Other than the above embodiment, the configuration of each part of the frame, the manner of attaching the cord heater to the frame, etc. can be changed as appropriate.

DESCRIPTION OF SYMBOLS 10... Refrigeration showcase, 11... Case main body, 12... Storage room, 17A... Top surface, 35... Air outlet, 40, 140, 240, 340, 440, 540, 640, 740, 840... Glass door, 41... Plate Shaped glass 41A, 841A First region 41B, 841B Second region 42 Peripheral edge 43 Outer surface 45 Glass 45A Glass surface 47 Thermal insulation layer 50 Frame 50A , 550A, 650A, 850A... First part 50B, 550B, 650B, 850B... Second part 51... Upper frame part 52... Side frame part 52A... Lower part 52B... Upper part 53... Lower frame Part 55... Resin member 56... Metal member 57... Support wall part 59... Locking part 60, 160, 260, 360, 460, 560, 660, 860... Cord heater 60A, 160A, 260A, 360A , 860A... First heater wire, 60B, 160B, 260B, 360B, 860B... Second heater wire, 61... First cord heater, 62... Second cord heater, 70, 770, 870... Glass heater, 71... Transparent conductive Membrane 167 Connection part 460A, 560A, 660A Heater wire 873 Electrode

Claims (16)

A refrigerated showcase comprising a glass door for opening and closing an opening of a storage compartment,
The glass door is
sheet glass;
a frame that holds the peripheral edge of the sheet glass;
a cord heater routed along at least a portion of the frame;
a glass heater made of a transparent conductive film formed on the glass surface of the sheet glass,
The frame is
a first portion arranged adjacent to the first region of the sheet glass and to which a predetermined amount of heat is transferred from the cord heater;
a second portion arranged adjacent to the second region of the sheet glass and to which a heat quantity smaller than that of the first portion is transferred from the cord heater ;
The glass heater is such that the temperature of the outer side surface of the first region of the sheet glass falls below the dew point temperature when only the glass heater is energized and the cord heater is not energized during the cooling operation. A refrigerated showcase set to a calorific value . A case body having the storage chamber that opens to the front,
The storage compartment has a cold air outlet for cooling the inside of the storage compartment on the back side of the top surface,
2. The refrigerated showcase according to claim 1, wherein the sheet glass has the first area located at the bottom and the second area located at the top. The cord heater includes a first heater wire routed along the first portion and a second heater wire routed along the second portion, and a calorific value of the second heater wire 3. The refrigerating showcase according to claim 1, wherein the calorific value of the first heater wire is smaller than that of the first heater wire. 4. The refrigeration showcase according to claim 3, wherein said cord heater comprises a first cord heater having said first heater wire and a second cord heater having said second heater wire. 4. In said cord heater, said second heater wire has a resistance value smaller than that of said first heater wire, and said first heater wire and said second heater wire are connected in series. The refrigerated showcase described in . 4. The refrigeration showcase according to claim 3, wherein said cord heater is a variable resistance cord heater in which said first heater wire and said second heater wire having a resistance value smaller than that of said first heater wire are integrated. 4. The refrigerating showcase according to claim 3, wherein said cord heater is configured such that the amount of heat generated decreases from said first heater wire toward said second heater wire. 3. The refrigerating showcase according to claim 1, wherein the cord heater has a heater wire routed along the first portion and not routed along the second portion. The frame includes an upper frame portion that holds an upper edge portion of the sheet glass, a pair of side frame portions that hold both side edge portions of the sheet glass, and a lower edge portion of the sheet glass. a lower frame portion;
The first portion is a lower portion positioned relatively below the lower frame portion and the pair of side frame portions,
9. The refrigerated showcase according to any one of claims 1 to 8, wherein the second portion is an upper portion of the pair of side frame portions positioned relatively upward and the upper frame portion. The frame includes an upper frame portion that holds an upper edge portion of the sheet glass, a pair of side frame portions that hold both side edge portions of the sheet glass, and a lower edge portion of the sheet glass. a lower frame portion;
The first portion is the lower frame portion,
The refrigerated showcase according to any one of claims 1 to 8, wherein the second portion is the pair of side frame portions and the upper frame portion. The frame includes an upper frame portion that holds an upper edge portion of the sheet glass, a pair of side frame portions that hold both side edge portions of the sheet glass, and a lower edge portion of the sheet glass. a lower frame portion;
The first portion is the lower frame portion and the pair of side frame portions,
The refrigerated showcase according to any one of claims 1 to 8, wherein the second portion is the upper frame portion. A refrigerated showcase comprising a glass door for opening and closing an opening of a storage compartment,
The glass door is
sheet glass;
a frame that holds the peripheral edge of the sheet glass;
a cord heater routed along at least a portion of the frame;
a glass heater made of a transparent conductive film formed on the glass surface of the sheet glass,
The frame is
a first portion arranged adjacent to the first region of the sheet glass and to which a predetermined amount of heat is transferred from the cord heater;
a second portion arranged adjacent to the second region of the sheet glass and to which a heat quantity smaller than that of the first portion is transferred from the cord heater ;
The refrigerated showcase, wherein the glass heater is configured such that the amount of heat generated in the first area of the sheet glass is smaller than the amount of heat generated in the second area of the sheet glass. A case body having the storage chamber that opens to the front,
The storage compartment has a cold air outlet for cooling the inside of the storage compartment on the back side of the top surface,
13. The refrigerated showcase according to claim 12, wherein the sheet glass has the first area located at the top and the second area located at the bottom. The glass heater is provided with a pair of electrodes at positions opposed to each other at the peripheral end portion of the transparent conductive film,
12 or 13, wherein the pair of electrodes is arranged at a position corresponding to the second region of the sheet glass and is not arranged at a position corresponding to the first region of the sheet glass. The refrigerated showcase according to claim 13 . 15. The refrigerated showcase according to any one of claims 1 to 14 , wherein the sheet glass is a multi-layered glass in which a pair of glasses are laminated via a heat insulating layer. The frame includes a resin member positioned inside the container and a metal member positioned outside the container when the glass door is closed,
16. The metal member according to any one of claims 1 to 15, wherein the metal member has a support wall portion that supports the surface of the outer side of the refrigerator in the peripheral edge portion of the sheet glass, and a locking portion that locks the cord heater. or the refrigerated showcase according to item 1 .

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