JPH0515952B2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention uses a coating having a heat ray reflecting function provided on a see-through plate used for doors and windows of low-temperature show cases to also serve as a dew-proof heater. Regarding.

(b) Prior art For example, Japanese Utility Model Publication No. 60-38860 has a transparent plate provided with a heat ray reflective film on the back surface of which is made of a conductive metal and has a vapor deposited layer with excellent visible light transmittance and heat reflectance. A transparent plate is disclosed in which the vapor deposited layer is provided with a plurality of slits spaced apart from each other, and the vapor deposited layer is used as an electric heating element.

(C) Problems to be Solved by the Invention In the above-mentioned conventional technology, since the heat ray reflective film is attached to the back surface of the transparent plate with an adhesive layer, for example, when the cooling operation is stopped due to a failure of the refrigeration equipment, As the temperature inside the refrigerator increases, the temperature of the heat ray reflective film itself, which self-generates heat when energized, also rises. For example, when it becomes higher than the softening temperature of the glue layer, the glue layer softens and expands. Shrinkage occurs in the film that is pasted as it softens, and this shrinkage causes displacement or wrinkles.Furthermore, the film may be lifted due to wrinkles, and as a result, However, problems have arisen in that the see-through effect of the see-through plate and the heat conduction from the coating to the transparent plate are reduced. The present invention aims to solve the above problems.

(d) Means for Solving the Problems The present invention has been made to solve the above problems, and will be described below based on an example. and a transparent glue layer 24, and the rectangular coating 11, 12, 1 is attached to one surface of the transparent plate with the glue layer.
3, the temperature of the coating 11 is sensed and the coating 11 is heated at a temperature lower than the softening temperature of the glue layer, for example, 50°C.
An energization cutoff device 50 that cuts off energization to 12 and 13
The present invention provides a see-through plate comprising:

(E) Effect According to the embodiment, when the thermostat 57 that controls the operation of the cooling device of the low-temperature case 1 fails, the power supply to the compressor 10 is stopped;
Electricity is continued to be applied to each coating, and therefore each coating 11, 12, which is generating heat due to electricity supply,
When the temperature of 13 gradually rises, the current cutoff device 5
0 is turned off at a temperature lower than the softening temperature of the coating 11, and electricity supply to each coating is stopped. Glue layer 24 due to heat generation of each coating 11, 12, 13 due to this off operation
Softening can be avoided.

(F) Embodiment Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

1 shown in Figures 3 and 4 has a door body 3 on the front,
A storage such as a refrigerated case or the like whose main body is composed of an insulating wall 2 having an opening for taking in and taking out products that can be opened and closed by a wall 3, and a plurality of fences are provided in the interior 2A defined by the insulating wall. 2B, a partition plate 4 is provided along the back wall to form a cold air passage 5 in which a cooler E and a blower F are installed, and a machine room B formed at the bottom of the main body is provided with a partition plate 4 along the back wall. A compressor P, a condenser C, etc., which together with the refrigerator constitute a refrigeration cycle, are installed, and the cold air that has been heat exchanged with the cooler is forcedly circulated with a blower F as shown by the arrow in Fig. 4 to cool the interior A of the refrigerator. It is something to do.

As shown in FIGS. 1 and 2, the door bodies 3, 3 are composed of a transparent plate 6 and a frame member 7 provided at the periphery of the transparent plate, and the transparent plate 6 includes a spacer 3A and a frame member 7 provided at the periphery of the transparent plate 6. The outside and inside of the refrigerator are made of transparent glass or synthetic resin plates, etc., which are polymerized with a gap between them.
transparent plates 6A, 6B, and one side adjacent to the inside side of the transparent plate 6A on the outside of the refrigerator, that is, the long side 11A, 11.
The upper and lower ends of B and 11C are electrically insulated apart, that is, the long sides 11A, 12A, and 13A in FIG.
0.5 with no electrical leakage
Three rows of strip-shaped coatings 11, 12, 13 provided with slits 8, 9 of 2 mm or more, for example, 2 mm;
Both short sides 11B, 1 of these coatings 11, 12, 13
2B, 13B and elongated conductive bands 16 to 19 provided across the transparent plate 6A.

Below, coatings 11, 12, 13 and conductive bands 16-
19 will be explained in detail. each coating 11,
Nos. 12 and 13 are made of similar components and have excellent visible light transmittance and heat reflectance, and in the case of films mainly used, as shown in Fig. 5, they have a heat resistance temperature of 100 to 120°C. A base layer 21 made of polyester or the like, a vapor deposition layer 22 made of a conductive metal such as a metal and/or a metal oxide such as silver and/or titanium oxide or aluminum and deposited on one surface of the base layer 21, that is, a selective transmission reflection layer 22, and a transparent Protective layer 23
It is constructed by sequentially polymerizing and laminating layers. In addition, each coating 11, 12, 13 has an allowable current of 1.5 to 2A,
It has moisture-proofing and selective transmission/reflection functions, transmits visible light and reflects infrared rays, and is made of a transparent acrylic adhesive layer 24 that softens at 60 to 70°C and dissolves at approximately 110°C. It is pasted on the back of 6A.
In addition, when the coatings 11, 12, 13 are located in the heat insulation space between the transparent plates 6A, 6B as in the above embodiment, the transparent protective layer 23 of the coatings 11, 12, 13
can also be omitted. Also, conductive bands 16 to 19
For example, the width is 8mm and the electrical resistance of each is 0.018Ω/cm
The conductive band 16 is made of an alloy of silver and other metals, and the conductive band 16 is provided over the entire width of one short side 11B of the coating 11, and a lead wire 26 is connected to the appropriate position by soldering or the like. A variable resistor 41 that adjusts the applied voltage is connected between and a power source (not shown). Further, the conductive band 17 is provided so as to span the other short side 11B of the coating 11 and one short side 12B of the coating 12, and the conductive band 18 is provided so as to span the other short side 12B of the coating 12 and the coating 13.
It is provided so as to straddle one short side 13B of. Further, the conductive band 19 is connected to the other short side 1 of the coating 13.
3B, and a lead wire 27 is connected to the appropriate position by soldering or the like. Due to the arrangement of these conductive bands 16-19, the coatings 11, 12, 13 are electrically connected in series via the conductive bands 16-19.

The electric circuit of the low-temperature show case will be explained below.

50 is a current cutoff device such as a thermistor or bimetal thermometer attached to the surface of the coating 11;
51 is a current prevention device, 52 and 53 are coatings 11,
This is a manual switch that forcibly turns on and off power to 12 and 13 in conjunction with each other, and includes an AC power supply 54, a manual switch 52, a current cutoff device 50, a conductive band 16, a variable resistor 41, a coating 11, a conductive band 17, a coating 12, The conductive band 18, the coating 13, the conductive band 19, and the manual switch 53 are connected in a ring. Here, the current cutoff device 50 is operated, for example, at the heat resistant temperature of the coatings 11, 12, 13, that is, the lowest heat resistant temperature among the glue layer 24, base layer 21, selective transmission reflective layer 22, etc., for example, from 60 to the softening temperature of the glue layer. It turns off when it senses a temperature lower than 70°C, for example 50°C. Incidentally, an AC power supply 54, a compressor 10, a starting relay 55, an overload relay 56, and a thermostat 57 are connected in a ring.

During normal cooling operation in the above electric circuit,
The supply of electricity to the compressor 10 is controlled based on whether the thermostat 57 is turned on or off, and the temperature inside the refrigerator is kept substantially constant. Here, for example, when the thermostat 57 fails and continues to be turned off, the internal temperature of the low-temperature case 1 gradually rises, and the temperature of the coatings 11, 12, 13 themselves, which are continuously energized, also rises. Then, the current cutoff device 50
1, and when the coating 11 reaches 50°C, the current cutoff device 50 turns off, and each coating 11, 1
By de-energizing 2 and 13, each coating 11,
The temperatures of 12 and 13 are gradually lowered, and softening of the glue layer 24 is avoided.

On the other hand, when connecting the lead wire 26, preferably, as shown in FIG.
By preventing the coating 11 from being affected by the heat generated by the electric iron during soldering during connection, it is possible to avoid damage such as melting of the coating periphery due to the electric iron. Incidentally, the conductive band 19 may be formed in the same manner as the conductive band 16 shown in FIG. Also, the seventh
The figure shows a preferred embodiment of the conductive band 17, and a protrusion 17A extending outward is formed at a portion at the approximate center of the conductive band 17, which is the boundary between the coatings 11 and 12, that is, a portion corresponding to the slit 8. Due to this protrusion, the area at the approximate center of the conductive band 17 for allowing current to flow from one end of the conductive band 17 to the other becomes wider, making it easier for the current to flow, and making the current flow between the respective coatings even better. .

The state of the transparent plate 6A when a commercial voltage (AC 100V) is applied between the lead wires 26 and 27 will be described below. The dimensions of the coatings 11, 12, and 13 are, for example, about 170 mm on the short side, about 1340 mm on the long side, about 1330 mm between the upper and lower conductive bands, and the width of the conductive bands 16 to 19 is about 8 mm. Further, the area specific resistance of the coatings 11, 12, and 13 is approximately 8 to 11Ω, and the resistance value of each coating is determined by the formula a/b×d=R (a: length of the resistor, b: width of the resistor, d: area specific resistance), a=1330, b=170, d=10
By substituting , it becomes 1330/170×10≒78.2 [Ω].

Here, when a commercial voltage is applied as described above, the current flows through the conductive band 16, the coating 11, the conductive band 17,
Coating 12, conductive band 18, coating 13, and conductive band 1
Flows through 9. The heat generation amount of the coatings 11, 12, and 13 is approximately 43 W in total, and when the temperature inside the refrigerator is 2°C and the temperature outside the refrigerator is 30°C, the temperature of each film is approximately 27°C, and the surface temperature of the transparent plate 6A is approximately The temperature will be 26℃. Also, conductive band 1
6 to 19 are the short sides 1 of the coatings 11, 12, and 13, respectively.
1B, 12B, and 13B, and conductive bands 17 and 18 are provided over the entire width of coating 1B, 12B, and 13B, respectively.
1 and 12 and between coatings 12 and 13, current flows through conductive bands 17 and 18 between coatings 11 and 12 and between coatings 12 and 13,
Further, the current flows linearly across the entire width from the opposing conductive bands 16 to 19 to the respective coatings 11, 12, 13, and flows uniformly through each coating 11, 12, 13.

According to this configuration, the coatings 11, 12, and 13 provided on the transparent plate 6A transmit visible light and reflect infrared rays, so that an increase in temperature inside the refrigerator due to the infrared rays can be avoided, and in addition, infrared rays are reflected to the outside of the refrigerator. By doing so, the surface temperature of the transparent plate 6A can be increased, and in addition, the respective coatings 11, 1
2 and 13 are electrically connected in series via the conductive bands 17 and 18, so that the conductive band 16 is connected to the coating 1.
1, 12, 13 and the conductive bands 17, 18 to the conductive band 19 by increasing the resistance value and decreasing the current value when voltage is applied.
13 in a substantially straight line over the entire width of the transparent plate 6A.
It is possible to eliminate dew condensation and improve the perspective effect. As shown in FIG. 1, by providing a variable resistor 41 on the lead wire 26, the amount of heat generated by each coating 11, 12, 13 can be changed in accordance with the temperature and humidity conditions inside and outside the refrigerator.

Moreover, the short sides 11B, 12 of the coatings 11, 12, 13
Conductive bands 16 to 19 are provided over the entire width of B and 13B, and between the lower end short sides 11B and 12B of the coating 11 and the coating 12, and between the upper end short sides 12B and 13B of the coating 12 and the coating 13. , conductive bands 17 and 18 are provided, and current flows through these conductive bands to adjacent coatings, and the current flows through each conductive band 16.
~ 19 to each coating 11, 12, 13 over the entire width in a substantially straight line, and each coating 11, 12, 13
For example, conductive bands 17, 18 of slits 8, 9
It is possible to avoid concentration of current at the side edges, etc., and the current flows uniformly through each coating 11, 12, 13, allowing each coating to generate heat uniformly.

Further, when the operation control circuit of the low-temperature case 1 breaks down and the cooling operation is stopped, the temperature of each of the coatings 11, 12, and 13 that generate heat due to energization increases, and the temperature of the coating 11 causes the activation of the current cutoff device 50. When the temperature reaches the temperature, the current cutoff device 50 turns off and stops the current supply to each coating 11, 12, 13.
As a result, the temperature of each film does not rise, making it possible to avoid softening and melting of the glue layer 24, and preventing the occurrence of wrinkles, displacement, etc. in each film 11, 12, 13 due to softening or melting of the glue layer. As a result, it is possible to maintain the see-through effect of the see-through plate 6, and to maintain good heat conduction to the see-through plate 6A when electricity is applied to each coating 11, 12, 13.

In addition, when using a heat ray reflective film for the coatings 11, 12, and 13, one film with an area approximately equal to the combined area of the coatings 11, 12, and 13 is pasted on the see-through plate 6A, and then the film is cut at an appropriate position. A slit may be formed, or the slit may be cut at the same time as the sheet of film is attached. Furthermore, in advance, each coating 11,
Films cut to sizes 12 and 13 may be pasted at appropriate intervals. Further, as shown in FIG. 8, for example, a remaining coating portion 11C is provided at the lower end of the slit 8 between the coatings 11 and 12, and a conductive band 17 is connected to the lower end of the coatings 11 and 12 and the remaining portion 1C.
By completely covering 1C, the adhesion of the conductive band 17 to the coatings 11, 12 and the remaining portion 11C can be made uniform, and the same effects as in the above embodiment can be obtained. Incidentally, by providing a remaining portion at the upper end of the slit 9 between the coatings 12 and 13, the same effects as in the above embodiment can be obtained. Of course, the upper end between the coatings 12 and 13 may have a similar structure.

Moreover, since the base layer 21 of the heat ray reflective film itself has electrical insulation properties, as shown in FIGS. 9 and 10, parts of the coatings 11, 12, and 13 are overlapped and attached to the transparent plate 6A. However, electrically insulating bands 30 and 31 may be provided over both the upper and lower ends, a conductive band may be applied, and an energization cutoff device may be provided that senses the temperature of the coating 11 and cuts off the energization.

Furthermore, in the above embodiment, three coatings 1
Although the transparent plate 6A to which the coatings 1, 12, and 13 are attached has been described, for example, when the transparent plate 6A is used for the door body of a low-temperature show case where the internal temperature is lower, for example, -20°C, the coatings 11, 12, and 13 are attached. By using one or two films with wider widths and connecting them in series, the combined resistance becomes smaller than in the case of three films, and the amount of heat generated when commercial voltage is applied can be increased. Also, on the contrary, transparent plate 6A
When used for the door body of a low-temperature show case with a high internal temperature of 8°C, for example, the coatings 11, 1
By using, for example, four films with a narrower width than those of 2 and 13 and connecting them in series, the combined resistance will be larger than in the case of three films, and the amount of heat generated when commercial voltage is applied can be reduced. .

In addition, as shown in FIG. 11, for example, in the conductive bands 16 and 19 whose main component is silver, the width of the connecting portions with the lead wires 26 and 27 is widened, and the width gradually decreases as the distance from this connecting portion increases. The conductive bands 16 and 19 are provided so that the conductive bands 16 and 19 are narrow, and the width L ₁ of the conductive bands 17 and 18 is widened at the center thereof, that is, at one end of the slits 8 and 9, and further away from the center. _{The conductive} bands _{16 ,}
It is possible to make the current density uniform by avoiding deviation of the current density of each conductive band due to the small resistance of the conductive band 19, and as a result, it is possible to avoid partial heating of each of the conductive bands 16 to 19. Further, by providing the current cutoff device 50 on the coating 11, the same effects as in the above embodiment can be obtained. Incidentally, when a material having a very low resistance value, such as gold, is used as the conductive band, the width of each conductive band may be made equal as shown in FIG.

(g) Effects of the invention For example, when cooling operation is not performed due to a failure of the temperature control device of a low-temperature show case and the temperature of each coating that generates heat due to energization rises, the current cutoff device operates to stop the energization of each coating. Automatic stopping can avoid softening and melting of the adhesive layer of the coating, resulting in displacement and wrinkles of the coating,
Furthermore, it is possible to avoid partial lifting of the coating from the transparent plate, and as a result, good heat conduction from the coating to the transparent plate can be maintained over the entire surface of the coating, so that almost the entire surface of the transparent plate can be maintained. It is possible to prevent dew condensation, and to maintain the see-through effect of the see-through plate.

[Brief explanation of the drawing]

1 to 5 show an embodiment of the present invention,
Fig. 1 is a longitudinal sectional front view of a door body used in a low-temperature show case, Fig. 2 is a longitudinal sectional side view of the door body, Fig. 3 is a front view of the low-temperature show case, Fig. 4 is a longitudinal sectional side view of the show case, and Fig. 5 The figure is a sectional view of the main part of the door body, FIGS. 6 to 11 show other embodiments, FIG. 6 is an enlarged view of the connection between the lead wire and the conductive band, and FIG.
Figures 8 and 8 are enlarged views of the main parts of the conductive bands spread over adjacent films, and Figures 9 and 10 are cross-sectional views when parts of the three films are overlapped and adhered to a transparent plate.
FIG. 11 is a longitudinal sectional front view of the door body. 3... Door body, 6... Transparent plate, 6A... Transparent plate,
8, 9... Slit, 11, 12, 13... Coating, 16-19... Conductive band, 21... Base layer,
22...Selective transmission reflection layer, 24...Glue layer, 50...
...Electrification cutoff device.

Claims (1)

[Claims] 1. A transparent plate, at least a base layer, a selective transmission reflection layer made of a conductive metal vapor-deposited on one side of the base layer and having excellent visible light transmittance and heat reflectance, and a transparent plate provided on the other side of the base layer. a glue layer, a film capable of conducting electricity attached to one side of the transparent plate by the glue layer, and a film that senses the temperature of this film and is applied to the film at a temperature lower than the softening temperature of the glue layer. A see-through plate characterized in that it is equipped with an energization cutoff device that forcibly cuts off energization.