JPH0480318B2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention provides a temperature detection section in a part of the refrigerator,
This signal turns on the compressor of the refrigeration cycle.
This invention relates to a refrigeration device such as a refrigerator that controls OFF.

Structure of the conventional example and its problems The conventional example will be explained with reference to FIGS. 1 and 2. Reference numeral 1 denotes a refrigerator body, which is divided by a partition wall 2 into a freezer compartment 3 at the top and a refrigerator compartment 4 at the bottom. 5 is a compressor of the refrigeration cycle. Reference numeral 6 indicates a cooler for the refrigeration cycle, and reference numeral 7 indicates a blower for forced ventilation, both of which are installed within the partition wall 2. 8 is a temperature detection unit (hereinafter simply referred to as thermistor 8) that turns the compressor 5 on and off.
Detect the temperature. Further, a damper thermostat 9 is provided at the entrance of the refrigerator compartment 7 to adjust the amount of cold air flowing in. Next, to explain the electric circuit, after the compressor 5 is connected in parallel with the blower 7,
It is connected to a power source via a relay 10. 11
is a temperature control device with thermistor 8, resistors R ₁ , R ₂ ,
It is composed of R ₃ , R ₄ , R ₅ , and a comparator 12, and the output of the comparator 12 is sent to the relay 10 through a driver circuit (not shown) such as a transistor.
are connected to turn on and off.

In such a configuration, when the temperature inside the refrigerator is high, the resistance value of the thermistor 8 becomes small, and the potential at point A determined by R _TH and R ₁ of the temperature control device 11 becomes higher than the resistance R ₂ , Since the potential at point B becomes higher than the potential determined by R ₃ and R ₄ and the output of the comparator 12 becomes "H", the relay 10 is turned on via a driver circuit such as a transistor (not shown), and the compressor 5, The blower 7 operates, and the blower 7 forces the cold air generated by the cooler 6 of the refrigeration cycle into the freezer compartment 3 and refrigerator compartment 4, and begins to cool the respective compartments.The resistance value of the thermistor 8 also increases. The potential at point V/1/R _TN +1/R ₁ begins to fall, but at the same time, the potential at point B to be compared becomes V/1/R ₃ +R ₂ +R ₃ +R ₄ /R ₂ (R ₃ +R ₄ )→ V/1+ _R2 /
Since R ₃ (1+R ₃ /R ₄ ) decreases and forms a differential, V/1/R _TH +1/R ₁ > V/1+R ₂ /R ₃ (1+R ₃ /R ₄ ) and continues cooling. do. After that, when the inside of the refrigerator is cooled down to a certain temperature, the resistance value _RTH of the thermistor 8 increases and the potential A becomes smaller than the potential at point B, so the output of the comparator 12 becomes "L" and turns off the relay 10. The compressor 5 and blower 7 are stopped. At the same time, the resistance value of the thermistor 8 decreases, and the potential at point A, V/1/R _TH +1/R ₁ , begins to rise, but the potential at point B also immediately increases to V/1+R ₂ /R ₃ (1+R ₃ / R ₄ )→V/1/R ₃ +R ₂ +R ₃ +
Since R ₄ /R ₂ (R ₃ +R ₄ ) switches to a high potential and forms a differential, V/1/R _TH +1/R ₁ <V/1/R ₃ +R ₂ +R ₃ +R ₄ / R ₂ (R
₃ + R ₄ ), and the stopped state continues. Thereafter, this action is repeated to perform a normal cooling action.

However, in actual use, such as when the door is frequently opened and closed, such a control method is often wasteful and may result in inefficient operation control. In other words, although there are many different types of food to be stored, this is represented by the temperature change of a temperature detection unit 11 such as a thermistor installed in a part of the refrigerator, and this temperature detection unit 11 is Normally, in order to sensitively detect the door opening/closing and the heat load inside the refrigerator, they are located at a position where they can be easily detected, or the heat capacity is relatively easy to detect. Even if the food inside is kept at a sufficiently low temperature by its own heat capacity, the temperature detection unit 11 will detect a rise in temperature every time the door is opened and closed, and it will issue a command to stop the compressor. It is difficult to reach the predetermined temperature _t2 , which is slightly higher than the stop command temperature, and the compressor is maintained at a temperature slightly higher than the stop command temperature, and the compressor cannot be stopped, resulting in unnecessary cooling operation, which is not efficient in terms of power saving. This had the disadvantage of resulting in poor control.

OBJECTS OF THE INVENTION In view of the above points, the present invention aims to prevent unnecessary continuation of cooling operation during high loads such as when doors are frequently opened and closed.

Structure of the Invention In order to achieve this object, the present invention detects a rise in temperature inside the refrigerator and turns on the compressor of the refrigeration cycle.
Another reference temperature is provided in the temperature control device at a temperature between the ON temperature at which the compressor is turned off and the OFF temperature at which the compressor is turned off by detecting a drop in the temperature inside the refrigerator, and which is slightly higher than the OFF temperature. The internal temperature is above
By providing an auxiliary stop device that turns off the compressor when the state of being above the OFF temperature and below the reference temperature continues for a predetermined period of time or more, cooling operation is prevented from being continued unnecessarily during loads such as opening and closing of doors. It is something.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3, 4, 5, and 5. Incidentally, the same parts as those in the prior art are denoted by the same reference numerals, and the description thereof will be omitted. In the figure, 11' is a temperature control device, and the normal temperature control section includes the resistance value R _TH of the thermistor 8, resistance R ₁ , R ₂ , R ₃ ,
When the potential at _{point A} , which is composed of the R 4 and R ₅ comparators 12 and determined by the resistors R _TH and R ₁ of the thermistor 8, is higher than the potential at point B, which is determined by the resistors R ₂ , R ₃ , and R ₄ . , the output of the comparator 12 is “H”, and conversely, the potential at point A is the resistance R ₂ , R ₃ , R ₄ ,
The output of the comparator 9 is set to be "L" when the potential is lower than the potential at point B determined by _R5 . Another temperature control section is composed of the resistor R _TH of the thermistor 8, resistors R ₁ , R ₆ , R ₇ , and a comparator 13, and the potential at the point A is the resistor.
If the potential is higher than the potential at point C determined by R ₆ and R ₇ , the output is “H”; if it is lower, the output is “L”
It is configured so that However, in this case, the potential at point C is preset to be slightly higher than the potential at point B. That is, V/1/R ₆ +1/R ₇ >V/1+R ₂ /R ₃ (1+R ₃ /R ₄ ).

Next, the output of the comparator 12 is output from the AND circuit 14.
The output of the comparator 13 is converted by an inverter 15 and connected to a timer 16. The timer 16 is configured to accumulate the time during which the input side is "H" and generate an output signal "H" only when the integration of a predetermined time T is completed. Resetting is performed by inputting an "L" signal to the input side. The output of the timer 16 is connected to the other input of the AND circuit 14 via an inverter 17, and the output of the AND circuit 14 turns the relay 10 ON/OFF.
16' indicates that the temperature remains below the reference temperature for a predetermined time T.
This is an auxiliary stop device that stops the compressor 5 after the time has elapsed.

Next, the operating situation in this configuration will be explained with reference to FIG. First, under normal stable operating conditions, when the temperature of the thermistor 8 installed in the refrigerator rises to a predetermined value _t1 , the thermistor 8
The potential at point A determined by the resistance value _RTH and resistor _R1 becomes higher than the potential at point B determined by resistors _R2 , _R3 , and _R4 , and the output of comparator 12 becomes "H". Become. At the same time, since the potential at point A exceeds the potential at point C, the output of comparator 13 also becomes "H", but since it is converted to "C" by inverter 15, the output of timer 16 is "L". This is converted to "H" by the inverter 17, so eventually
Both inputs of the AND circuit 14 become "H", and the output of the AND circuit 14 becomes "H".
The relay 10 is turned on, the compressor 5 and the blower 7 are operated, and the inside of the refrigerator is cooled. After that, when the temperature of the thermistor 8 decreases to a predetermined value t ₂ °C, the potential at point A determined by the resistance value R _TH of the thermistor 8 and the resistor R ₁ changes to the resistors R ₂ , R ₃ , R ₄ , R ₅ When the potential of the comparator 12 becomes "L" as the potential becomes lower than the potential at point B determined by the above, the output of the AND circuit 14 becomes "L", the relay 10 is turned off, and the compressor 5 and blower 7 are stopped. In this case, the potential at point C determined by resistors R ₆ and R ₇ is set slightly higher than the potential at point B, and comparator 13 outputs "L" earlier than comparator 12. However, since the "L" signal is not finally sent to the AND circuit 14 until after the timer 16 has integrated T for a predetermined time, the output of the comparator 12 becomes "L" during that time, turning off the relay 10. Take control. In this way, normal cooling operation is repeated.

Next, during cooling operation, if the door is opened and closed frequently, the temperature drop gradient of the thermistor 8 will be gradual and it will be difficult to reach the predetermined temperature t ₂ °C, but it will be difficult to reach the predetermined temperature t ₁ °C and t _{2 °C} . _{C _}
The output of the comparator 13 becomes "L" as the potential becomes lower than that of the point, and is converted to "H" by the inverter 15, and the timer 16 starts time integration.
Thereafter, even if the temperature of the thermistor 8 has not yet reached t ₂ °C, when the timer 16 completes the integration of the predetermined time T, an output "H" is generated, which is converted to "L" by the inverter 17 and output from the AND circuit 14. Turn off relay 10 as “L”, compressor 5, blower 7
As shown in Figure 3, as shown in Figure 3, the supercooling region shown by diagonal lines in the conventional example is almost eliminated, and there is no waste when cooling is continued even though the food is sufficiently cooled. Efficient cooling can be performed.

Effects of the Invention As is clear from the above explanation, the present invention detects a rise in temperature inside the refrigerator and operates the compressor of the refrigeration cycle.
Another reference temperature is set between the ON temperature at which the compressor is turned on and the OFF temperature at which the compressor is turned off by detecting a drop in the temperature inside the refrigerator, and is slightly higher than the OFF temperature. The compressor is configured to turn off even if the state of the OFF temperature or more and the reference temperature or less continues for a predetermined time or more, so if the door is frequently opened and closed during cooling operation, etc., the temperature detection section The temperature drop gradient becomes gradual, making it difficult to reach the predetermined compressor OFF temperature, and even if it remains just before that temperature for a long time, it is possible to issue a command to forcibly turn off the compressor, so the food It does not continue cooling unnecessarily even though it has been sufficiently cooled and does not result in overcooling, and wasteful cooling operation can be eliminated, which has an extremely high practical effect in terms of power saving.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a refrigerator showing a conventional example, FIG. 2 is a control circuit diagram thereof, FIG. 3 is a schematic sectional view of a refrigerator showing an embodiment of the present invention, and FIG. 4 is a control circuit diagram thereof. FIG. 5 is a temperature characteristic diagram. 5...Compressor, 11'...Temperature control device, 1
6'...Auxiliary stop device.

Claims (1)

[Claims] 1. An ON temperature that detects an increase in the temperature inside the refrigerator and turns on the compressor of the refrigeration cycle, and an OFF temperature that detects a decrease in the temperature inside the refrigerator and turns off the compressor,
The temperature inside the refrigerator is compared with another reference temperature, which is between the ON temperature and the OFF temperature, and is set slightly higher than the OFF temperature, and a signal is output to turn the compressor on and off. and a temperature control device that controls the temperature control device, and an output signal of the temperature control device is input, and when the temperature inside the refrigerator continues to be above the OFF temperature and below the reference temperature for a predetermined period of time, the compressor is turned off.
Refrigeration equipment equipped with an auxiliary stop device that turns it off.