JPS6033225B2 - temperature control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature control device suitable for, for example, a vending machine.

Examples of devices that use this type of temperature control device include refrigerators, vending machines, and showcases. The lower part is configured as a machine room that houses heat sources such as refrigeration cycles.

A product storage column for storing products is arranged in the product storage, and a compressor, a condenser, etc. that constitute a refrigeration cycle are arranged in the machine room along with an evaporator located at the bottom of the product storage. . In order to cool and maintain the inside of the product storage at a predetermined temperature, the operation of the refrigeration cycle compressor is controlled by a thermostat placed near the evaporator, and a circulation fan placed near the evaporator is driven. Cool air is forced to circulate by continuously rotating the fan motor. Therefore, in the above-mentioned method of controlling the temperature inside the refrigerator, the fan motor is constantly rotating, which consumes a large amount of electricity, which has become a serious problem in today's society where energy conservation is discouraged. ing. On the other hand, from the viewpoint of power saving, it is conceivable to operate the fan motor intermittently like the compressor, but in this case, a problem occurs in the defrosting operation. In other words, in the method of continuously rotating the fan motor that drives the circulation fan as described above, the evaporator is defrosted when the compressor of the refrigeration cycle is stopped. With the method of synchronously intermittent fan motors, defrosting becomes very surprising. The present invention was devised by considering the above points, and by using two thermostats that detect the temperature inside the refrigerator and a changeover switch, it is possible to reliably measure power saving and improve cooling efficiency, and also to increase sales frequency. The purpose of the present invention is to provide a temperature control device that can control temperature according to the temperature.

An embodiment of the present invention will be explained below based on the drawings.

1 and 2, 1 is a vending machine main body, and the inside of this main body 1 is divided into an upper chamber 3 and a lower chamber 4 by a partition wall 2, and the upper chamber 3 is a product storage for storing products. The lower chamber 4 serves as a product storage in which the column 5 is arranged, and the lower chamber 4, together with the evaporator 6 disposed at the bottom of the upper chamber 3, constitutes a refrigeration cycle as a heat source, including a compressor 7, a condenser 8, a condenser fan 9, and the condenser. This is a machine room in which the fan motor 10 that drives the fan 9, etc. are arranged.

Reference numeral 11 denotes a circulation fan provided at the bottom of the product storage 3 to circulate the air within the product storage 3, and together with a circulation fan motor 12 that drives the circulation fan 11, constitutes an air blower 13. are doing.

Further, a first thermostat 1 for controlling the operation of the compressor 7 is located near the evaporator 6.
A second thermostat 16 is provided below the product storage column 5 to detect the temperature of the product A and control the circulation fan motor 12 and the compressor 7. FIG. 3 shows an electric circuit diagram of the temperature control device of the present invention. Reference numerals 1, 12 are power supply busbars, and the compressor 7 and the first thermostat 14 are connected between the power supply busbars 1, 12. A series circuit is connected via a parallel circuit between the second thermostat 15 and a changeover switch 16 provided at an appropriate position on the main body of the vending machine 1, and the circulation fan motor 12 is The power supply bus 1,
, 12.

The second thermostat 15 is set to have a larger differential or a higher ON operating point than the first thermostat 14; for example, the upper limit temperature at which the second thermostat 15 turns ON is set. 10℃,
The lower limit temperature for turning off the first thermostat 14 is set at 5°C, the upper limit temperature for turning on the first thermostat 14 is set at 4°C, and the lower limit temperature for turning off the first thermostat 14 is set at 0°C. The operation of the temperature control device having the above configuration will be explained based on the timing chart of FIG. 4.

If the vending machine is installed at a place where sales are not frequent, the changeover switch 16 is opened and operated. Therefore, when the temperature of the product A stored in the product storage column 5 is high, the second thermostat 15 senses the temperature and closes the thermostat 15. When the power is turned on (at point L), the circulation fan motor 12 operates via the second thermostat 15, and the air inside the product storage 3 is circulated by the rotation of the circulation fan 11.
Forced circulation. After this, the first thermostat 14 senses the circulating air temperature (at the point in time).
By closing, the compressor 7 is activated. As a result, the cooling operation inside the product storage 3 is started, and when the cooling operation progresses and the temperature near the bottom of the product storage 3 reaches the lower limit temperature of the first thermostat 14,
That is, at the time point, the first thermostat 1
4 performs an opening operation in response to the temperature of the circulating air, and stops the operation of the compressor 7. After this, air is continuously circulated inside the product storage 3 by the rotation of the circulation fan 11, and the temperature of the air gradually rises, causing the temperature near the first thermostat 14 to increase. When the upper limit temperature is reached (time point 3), the first thermostat 14 is opened again and the same cooling operation as described above is performed. By the way, during the above cooling operation,
In the vicinity of the second thermostat 15, which is located approximately in the middle of the product storage 3, it takes a long time to reach the lower limit temperature of the thermostat 15. The switching operation does not occur, and only the circulation fan motor 12 continues to rotate. Therefore, when the circulation fan motor 12 is rotating and the compressor 7 is stopped, that is, during the period t3-t5 or t5-t6 in the timing chart of FIG.
During this period, defrosting will be carried out on Evaporation Day 6.
Therefore, the cooling operation is performed by the second thermostat 1.
5 decreases to the lower limit temperature of this thermostat 15, and the contact point of the thermostat 15 opens (t
7). Due to such cooling operation, the area near the bottom of the product storage 3 is kept below the lower limit temperature of the first thermostat 14, and the area near the second thermostat 15 is kept below the lower limit temperature of this thermostat 15. , the first thermostat 14 and the second thermostat
Both the thermostats 15 remain open, the compressor 7 and the circulation fan motor 12 are both stopped (period -t8), and the cold air stays below the product storage 3. to a predetermined state. Further, when the temperature near the second thermostat 15 rises above the upper limit temperature of this thermostat 15, the second thermostat 15 closes, the circulation fan motor 12 operates (at time t3), and the same as described above occurs. Start cooling operation. In this way, the circulation fan motor 12 is operated intermittently depending on the temperature inside the product storage 3. On the other hand, if the vending machine is frequently sold at a location where the vending machine is installed, the changeover switch 16 is closed and activated. That is, the changeover switch 16 is closed (
b), the circulation fan motor 12 rotates continuously regardless of the temperature inside the product storage 3, and the compressor 7 operates intermittently depending on the temperature near the bottom of the product storage 3. be done. In the above embodiment, a method has been described in which the second thermostat 15 is arranged approximately in the middle of the product storage 3 to locally cool the lower part of the product storage column 5. By placing 15 at the top of the product storage 3,
It is also possible to uniformly cool the product storage 3, and by changing the arrangement position of the second thermostat 15, local cooling and overall cooling can be set as desired. Further, in the above embodiment, a method of switching the changeover switch 16 according to the sales frequency at the installation location has been described, but the changeover switch is not limited to this.
For example, a program timer or a photo switch may be used, and in this case, the cooling state of the product storage 3 can be changed depending on the sales time or day or night. The present invention enables cooling according to the sales status by switching the changeover switch, enables efficient temperature control, and allows the operation of the circulation fan motor that drives the circulation fan to be switched continuously or intermittently. Therefore, it is possible to save power compared to the subordinate method.

In addition, the defrosting problem caused by intermittent driving of the circulation fan motor can be solved with a simple configuration without using a defrosting heater, etc., and a practical temperature control device that can improve cooling efficiency can be provided. It is something.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a vertical cross-sectional view of a vending machine, FIG. 2 is an enlarged view of the evaporator section, FIG. 3 is an electric circuit diagram, and FIG. 4 is an electrical circuit diagram. It is a timing chart figure. 3... Product storage, 7... Compressor, 6... Evaporator, 11... Circulation fan, 12... Circulation fan motor, 14
...First thermostat, 15...Second thermostat, 16. ...Selector switch. Figure 2 Figure 4 Figure 1 Figure 3

Claims (1)

[Claims] 1. A product storage for storing products, a cooling system consisting of a compressor, an evaporator, etc. for cooling the storage, a blower for circulating the air in the storage, and energization of the compressor installed in the storage. a first thermostat that controls the temperature, a second thermostat provided above the first thermostat, and a changeover switch; It is connected between the power supplies via a parallel circuit with the changeover switch, and the first
A temperature control device characterized by connecting a series circuit of a thermostat and a compressor.