JPH0718946Y2 - Dew-proof heater control circuit for refrigerated showcase with warm storage - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a control circuit for a dew-proof heater incorporated in a front transparent door of a refrigerated showcase with a refrigerator.

[Prior Art] First, an outline of a refrigerating showcase with a refrigerating cabinet, which is the object of the present invention, will be described with reference to FIGS. 3 and 4. In the figure, 1 is a showcase body, and 2 is a double-sided transparent front door that is composed of two left and right split doors 2L and 2R arranged in front of the showcase body. There is a hot room 3 at the top and a cold room 4 at the bottom.
Here, in the refrigerating room 3, a product display shelf 5, a heating heater 6 for heating the product, a fan 7 inside the refrigerating room 4, and in the refrigerating room 4, a product display shelf 8, a cooler.
9, 10 fans inside the cabinet. Reference numeral 11 is a condensing unit of the refrigerator, which includes a compressor 11a, a fan 11b, and a condenser 11c. In addition, the above-mentioned partition wall is provided with a communication ventilation port 12 that communicates between the heating chamber 3 and the refrigerating chamber 4 to communicate with each other according to the heating and cooling operation modes described later. A shutter mechanism 13 for opening and closing the mouth 12 is provided.

With such a configuration, the operation mode of the heating chamber 3 is switched to hot or cold in accordance with the seasons of winter and summer, for example, and used to sell products such as hot beverages and cold beverages. When the hot storage chamber 3 is hot-operated, the communication ventilation port 12 is closed by the shutter mechanism 13 and the storage heater 6 is energized to heat the stored products. On the other hand, the heating room 3
When switching to the cold operation mode, the energization of the heating heater 6 is stopped, and then the shutter mechanism 13 is operated to open the communication ventilation port 12. As a result, cool air is circulated from the refrigerating compartment 4 side through the communication ventilation opening 12 through the warm refrigerating compartment 3,
Cool the products stored in the hot room. In addition, the above-mentioned heating room 3,
Each of the refrigerating compartments 4 is equipped with a thermostat for adjusting the room temperature, and in actual operation, the above-mentioned refrigerator and warming heater are controlled to be turned on / off by the thermostat.

Further, in addition to the above-mentioned one warm room 3, the room is divided into two left and right chambers and has an independent mechanism, and a heating mode and a cold mode can be selected and operated for each divided room. There is.

On the other hand, the transparent front door 2 is fitted with two stacked transparent glass plates for each of the left and right split doors 2L and 2R, and a dew-proof heater 14 made of a transparent material is embedded between the glass plates.
The dew-proof heater 14 prevents fogging due to dew condensation on the transparent glass surface caused by opening and closing the front door 2, and most ordinary showcases with a transparent door are equipped with this dew-proof heater. The dew-proof heater is operated so as to always maintain the energized state during the operation of the refrigerating showcase.

[Problems to be solved by the device]

By the way, in the refrigerated showcase with the above refrigerator,
In addition to refrigerators for cold rooms and product heaters for hot rooms,
Equipped with electrical components such as dew-proof heaters that consume a considerable amount of power, the power consumption when energizing all of these electrical components at the same time is quite large. On the other hand, most users such as shops using the showcase are small electricity consumers, and the rated current of indoor wiring equipment in this case is about 15 A, and if a large current flows beyond this, the indoor wiring system will be There is a risk of overheating and a dangerous condition.

Therefore, regarding the refrigerated showcase with a refrigerator, it is desired to keep the total operating current of the entire showcase as low as possible in order to save electric power in addition to safety for indoor wiring.

However, in the case of a refrigerated showcase equipped with a refrigerator, which is equipped with a refrigerator, a product heating heater, a dew-proof heater, etc. as described above, the load current flowing through each electrical component individually depends on the size of the showcase. In practice, it is difficult to keep the total current value of (1) below the rated current (15A) of indoor wiring.

The present invention has been made in view of the above points, and the findings obtained through various experiments and studies, especially with respect to the dew-proof heater, while ensuring the current capacity required for each electrical component in terms of function. While maintaining the dew-proof function that does not hinder practical use,
Moreover, it is an object of the present invention to provide a dew-proof heater control circuit capable of reducing the total operating current of the entire refrigerated showcase with a warm storage.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, a refrigerating room and a heating room are defined in the interior of the showcase body, and the front surface of the showcase body is a transparent front surface with a dew-proof heater common to the refrigerating room and the heating room. A dew-proof heater control circuit for a refrigerated showcase with a refrigerator, which has a door, in which the refrigerator for the refrigerating compartment is in the energized condition, and the heater for heating the product installed in the refrigerator compartment is in the non-energized condition. The relay contact that is turned on by is connected in series with the dew-proof heater to form a dew-proof heater control circuit.

[Action]

With the above-mentioned configuration, the relay for controlling the energization of the dew-proof heater is an auxiliary relay interposed in the circuit of the warm-up heater installed in the warming room, and its normally open contact (contact b) is the heater of the circuit of the dew-proof heater. Are connected in series. Therefore, under the condition that the hot heater is energized, the relay contact is turned off and the dew-proof heater is stopped. On the other hand, when the thermostat for adjusting the room temperature installed in the hot room operates to stop the energization of the hot heater, the relay contact is switched on and the dew-proof heater is turned on. In other words, the warming heater and dew-proof heater installed in the warming room are not operated at the same time, and as a result, the total operating current value of the showcase as a whole is significantly lower than that of simultaneous operation. Will be done.

On the other hand, the inventor of the present invention has obtained the following knowledge through various experiments and consideration regarding the anti-condensation function by the operation control of the anti-condensation heater.

That is, in FIG. 4, when the heater 6 is energized in the heating chamber 3 to perform a hot operation, the area of the transparent front door 2 facing the heating chamber is the heat receiving surface, and the glass of the door 2 is viewed from the inside. Heat enters the surface. Moreover, the heat received in this portion is transferred to the inside of the glass layer toward the area facing the refrigerating compartment due to the temperature difference between the refrigerating compartment 4 side. Then, an experiment was conducted in which the energization of the dew-proof heater 14 was stopped in this state, and when the heating heater 6 of the heating chamber 3 was energized, it depended on the temperature and humidity conditions around the showcase. It was confirmed that the fogging generated on the glass surface of the transparent front door 2 including the region of the refrigerating chamber 4 is not a problem in practical use, especially under ambient conditions where the ambient temperature and the relative humidity are low. Therefore, the heating room 3
Even if the dew-proof heater 14 is de-energized when energizing the heating heater 6 installed in the refrigerating room as described above under ambient conditions where the ambient temperature and humidity are low, such as in the winter when the car is hot-operated, there is a practical problem. The dew-proof function can be maintained.

〔Example〕

FIG. 1 shows an operation control circuit of a refrigerating showcase with a refrigerator according to an embodiment of the present invention. Particularly, the heating chamber 3 described in FIG. 4 is divided into left and right split doors 2L, 2R of a transparent front door 2. Correspondingly, when divided into two left and right chambers. Symbols attached to various electric components constituting the circuit correspond to those in FIG. It should be noted that the heating heater 6, the internal fan 7, and the like installed in the heating room,
Further, the symbols L and R attached to the dew-proof heater 14 provided in the split front door means that they correspond to the left side and the right side, respectively. In addition, TH is a thermostat that is installed in the refrigerator room,
THL and THR are thermostats SWL and S deployed in the left and right heating compartments.
WR is an operation mode changeover switch for the left and right heating compartments, and 15 is an outlet for connecting the showcase to a power source. Here, according to the present invention, auxiliary relays XL and XR are connected in parallel with the left and right heating chambers 6L and 6R, respectively, and the relay contacts (contacts b) of the auxiliary relays XL and XR are dew-proof. Heater 14L, 1
It is connected in series with 4R.

Heater heaters 6L, 6R and dew-proof heaters 14L, 14R
The energization operation time chart of is as shown in FIG. That is, the dew-proof heater 14L is turned off when the warm-up heater 6L is energized, and is turned on when the warm-up heater 6L is de-energized by the operation of the room temperature adjusting thermostat THL.
Similarly, the dew-proof heater 14R is turned off when the warming heater 6R is energized, and is turned on under non-energized conditions, so that the warming heater 6L and the dew-proofing heater 14L and the warming heater 6R and the dew-proofing heater 14R are simultaneously operated. There is no such thing. When the operation modes of the left and right heating chambers are switched from the hot operation to the cold operation, the dew-proof heaters 14L and 14R are continuously energized.

[Effects of the Invention] Since the control circuit of the dew-proof heater according to the present invention is configured as described above, the following effects are obtained.

That is, the dew-proof heater is controlled so as to avoid simultaneous energization of the warm-up heater and the dew-proof heater, so the total operating current of the entire showcase is the continuous operation of the dew-proof heater as in the conventional method. It is significantly lower than when you do it. As a result, the operating current when operating in the installation location of the showcase can be suppressed below the rated current that is restricted by the indoor wiring equipment.

Moreover, as for the dew-proof function for the transparent front door of the showcase, the heat received from the refrigerating compartment is transferred to the glass surface area covering the front of the refrigerating compartment when the dew-proof heater is not energized. Since it prevents dew condensation and fogging on the part, it is possible to maintain the dew protection function that does not hinder practical use.

[Brief description of drawings]

FIG. 1 is an operation control circuit diagram of a showcase with a heating cabinet according to an embodiment of the present invention, FIG. 2 is an operation time chart showing an energization relationship between the heating heater and the dew-proof heater by the circuit of FIG. 1, and FIG. FIG. 4 and FIG. 4 are a perspective view and a cross-sectional view showing the internal structure of a showcase with a heating cabinet to which the present invention is applied. In the figure, 1: Showcase body, 2: Transparent front door, 3: Hot room, 4: Cold room, 6: Heater heater, 14: Dew-proof heater, XL, XR: Auxiliary relay.

Claims (1)

[Scope of utility model registration request] 1. A showcase body having a refrigerating room and a warming room defined therein, and the front of the showcase body having a transparent front door with a dew-proof heater common to the refrigerating room and the warming room. It is a dew-proof heater control circuit for a refrigerating showcase with a refrigerator, and the refrigerator for the refrigerating compartment is energized under the energized condition and the product heating heater installed in the refrigerator compartment is turned on under the de-energized condition. A dew-proof heater control circuit for a refrigerated showcase with a refrigerator, characterized in that a relay contact is connected in series with a dew-proof heater.