JPH0123709B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for controlling the forced cooling operation of a forced ventilation refrigerator-freezer.

Forced cooling control of a forced ventilation refrigerator-freezer is generally performed by continuously operating an electric compressor and a blower using a forced cooling switch. Therefore, continuous cooling operation is performed regardless of the temperature inside the refrigerator, and the temperature of the refrigerator compartment depends on the sealing between the damper thermostat and the ventilation opening, and the sealing between the partition wall between the freezer compartment and the refrigerator compartment. Otherwise, even if the damper thermostat was closed, the cold air in the freezer compartment would gradually enter the refrigerator compartment and be cooled down, resulting in the refrigerator compartment becoming below 0°C after a certain period of time. In addition, if forced cooling operation is started while the damper thermostat, which controls the temperature of the refrigerator compartment, is set to a high setting, the temperature of the refrigerator compartment will drop below 0℃ in a short period of time, causing the beverage to become too cold and resulting in poor taste. There were drawbacks that adversely affected the stored food in the refrigerator, such as deterioration and freezing of the stored food.

Therefore, in the present invention, a temperature detection element such as a thermistor that detects the temperature inside the refrigerator compartment is used to detect when the temperature in the refrigerator compartment becomes 0°C or less during forced cooling operation, and at this time, the temperature detection element in the freezer compartment is used to The compressor operation is stopped, and other than that, the forced cooling operation is stopped using a timer or a switch, and the inside of the refrigerator compartment is controlled so that the temperature does not drop below 0℃, and the forced cooling operation is controlled so as not to adversely affect the stored food. An object of the present invention is to provide a controlled forced cooling operation control circuit for a forced draft refrigerator-freezer.

An embodiment of the present invention will be described below.

Reference numeral 1 denotes a main body of the refrigerator, and a partition wall 2 is provided in the main body 1 to partition the inside of the main body 1 into a freezing compartment 3 and a refrigerating compartment 4. A cooling compartment A is formed in the partition wall 2 in which a cooler 5 and a blower 6 are arranged side by side.

The cooler 5 is provided with a defrost heater 7 that heats the cooler 5 during defrosting. Further, a drain pan 8 is disposed below the cooler 5.
A drain pan heater 9 for heating the drain pan 8 during defrosting is provided on the back surface of the drain pan heater 9. A drain port is provided at the lowest position of the drain pan 8, and the drain port 10 is connected to a drain pipe 1 from the drain port 10 to the inside of the refrigerator compartment 4.
1, and the drain pipe 11 is connected to a drain pipe 12 from inside the refrigerator compartment 4 to outside the main body 1, so that the defrosting water defrosted by the cooler 5 is drained to a predetermined position outside the refrigerator main body 1. It's getting old.

In the rear part of the compartment A, there is a ventilation pipe 1 that communicates with the ventilation ports 13 and 14 of the freezer compartment 3 and the refrigerator compartment 4.
5 is provided to forcefully ventilate the cooling air from the cooling compartment A to the freezing compartment 3 and the refrigerating compartment 4 to cool both compartments. Reference numeral 16 denotes a damper thermostat provided in the air outlet 14, which adjusts the amount of cooling air ventilated into the refrigerator compartment 4 and controls the interior of the refrigerator compartment 4 to a predetermined temperature. 17 is the internal temperature of the freezer compartment 3, 18
are thermistors (also referred to as temperature detection elements) that detect the internal temperature of the refrigerator compartment 4.

Next, the circuit shown in FIG. 2 will be explained. 19,2
0 is a power supply terminal, and 21 is an electric compressor. The power terminal 19 is connected to the electric compressor 21 and the blower 6. Reference numeral 22 denotes a relay, which has a normally open contact 23, which is connected to the power supply terminal 20, and whose other end is connected to the blower 6 and the electric compressor 21. 24 is an internal temperature detection circuit of the freezer compartment 3, which includes a thermistor 17,
It consists of a comparator 25 and resistors R ₁ , R ₂ , and R ₃ . Resistors R ₁ and R ₂ are connected to Vcc power supply, resistor R ₁
and the thermistor 17 are connected in series, and this connection point is connected to one input terminal of the comparator 25.
One end of the resistor _R3 and thermistor 17 is connected to GND. Resistors R ₂ and R ₃ are connected in series and connected to one input terminal of the comparator 25.

26 is an internal temperature detection circuit for the refrigerator compartment 4, which includes a thermistor 18, a comparator 27, and resistors R ₄ , R ₅ , R ₆
It consists of The resistor R ₄ and the thermistor 18 are connected in series, and the resistors R ₅ and R ₆ are connected in series to one input of the comparator 27, and are connected to the other input terminal of the comparator 27, and the other ends of the resistors R ₄ and R ₅ are connected in series.
The other end of thermistor 18 and resistor _R6 is connected to the Vcc power supply.
Connected to GND. 28 is an OR circuit, 29 is
It is an AND circuit. OR with the output of comparator 25
It is connected to one input of the circuit 28, and the other input of the OR circuit 28 is connected to the output of the AND circuit 29.
The output of OR circuit 28 is connected to the base of transistor ₃₁ via resistor R7. A relay 22 is connected to the collector of this transistor 31. The emitter of transistor 31 is connected to GND. The output of comparator 27 is AND
It is connected to one input of the circuit 29. 30 is an inverter circuit. Reference numeral 32 denotes an oscillation circuit, which is composed of gate circuits 33, 34, a resistor _R8 , and a capacitor _C1 .

One input of the gate circuit 33 is the inverter circuit 30
The other inputs of the gate circuit 33 are connected to the resistor _R8 and the capacitor _C1 . Further, the output of the gate circuit 33 and the input of the gate circuit 34 are connected, and also connected to one end of the resistor _R8 . The output of the gate circuit 34 is connected to the capacitor _C1 and the timer 35.
is connected to the input terminal.

The oscillation circuit 32 is configured to perform charge/discharge cycles and oscillate with a time constant determined by a resistor _R8 and a capacitor _C1 , and one input of the gate circuit 33,
In other words, oscillation continues while "0" is given to the input connected to the output of the inverter circuit 30, and "1"
It will stop when .

The timer 35 is a flip-flop circuit FF ₁ , FF ₂
...... It consists of 7 pieces of ₇ , and each Q output is connected to the clock input. Also, each output is connected to a data input. The final stage output of the timer 35 and one input of the OR circuit 39 are connected. The reset terminals are also connected to the outputs of the one-shot circuits 36, respectively.

The one-shot circuit 36 is configured to generate one positive pulse signal when the input signal changes from "1" to "0". 37 is a switch for forced cooling, connected to the Vcc power supply, and the other end connected to resistor R ₉ and the clock input of flip-flop circuit 38. The other end of resistor _R9 is connected to GND.
It is connected to the output and data input of the flip-flop circuit 38, and its Q output is connected to each input of the AND circuit 29, inverter circuit 30, and OR circuit ₃₉ , and further connected to the base of a transistor 40 via a resistor R10. The output of the AND circuit 39 is connected to the output of the one-shot circuit 36 and the reset terminal of the flip-flop 38. transistor 4
A resistor R ₁₁ is connected to the collector of 0, and a resistor R ₁₁
The display device 41 during strong cooling is connected to the other end, and the other end of the display device 41 during strong cooling is connected to the Vcc power supply. The emitter of transistor 40 is connected to GND. 42 is a control circuit for forced cooling operation that stops the forced cooling operation using a timer or a switch, which includes AND circuits 29, 39, inverter circuit 30, oscillation circuit 32, timer 35, flip-flop circuit 38, one-shot circuit 36, and for forced cooling. switch 37.

Next, the operation of the circuit configured as described above will be explained.

The thermistor 17 placed in the freezer compartment 3 has a small resistance value when the internal temperature is higher than the set value, and the resistance R ₂ is lower than the partial voltage potential of the resistor R ₁ and the thermistor 17.
Since the divided potential at R ₃ is higher, comparator 2
The output of 5 is "1". Since one input of the OR circuit 28 becomes "1", the output also becomes "1", and the transistor 31 is turned on via the base resistor _R7 of the transistor 31, thereby exciting the relay 22. When this relay 22 is energized, its normally open contact 23 is closed, and the power terminals 19 and 20 are connected to the electric compressor 21 and blower 6, and the electric compressor 21 and blower 6 are started, and cool air is supplied to each room. It cools the freezer compartment 3 and refrigerator compartment 4. In this way, the internal temperatures of the freezer compartment 3 and refrigerator compartment 4 are reduced by the operation of the electric compressor 21 and the blower 6. When the temperature of the freezer compartment 3 decreases, the resistance of the thermistor 17 gradually increases, and when it becomes lower than the set value, the thermistor 17
The resistance of the resistor _R1 and the thermistor 17 becomes higher than that of the resistors _R2 and _R3 , and the output of the comparator 25 becomes "0". When the output of the comparator 25 becomes “0”, the OR circuit 28
The output changes from "1" to "0", transistor 31 is turned off, and relay 22 stops operating. Normally open contact 2 due to relay 22 stopping operation
3 is opened, and the electric compressor 21 and blower 6 are disconnected from the power supply terminals 19 and 20 and stop operating.
As the cooling operation is stopped, the temperature inside the refrigerator gradually increases, and the resistance of the thermistor 17 decreases.When the temperature inside the refrigerator increases and exceeds the set value, the low resistance value of the thermistor 17 decreases, and as described above, the resistance of the thermistor 17 decreases.
5 becomes "1", and the electric compressor 21 and blower 6 start operating again and enter cooling operation. The refrigerator is maintained at the set temperature by repeating cooling operation and stopping as described above.

Next, forced cooling operation will be explained. When the forced cooling switch 37 is in the OFF state, the clock input of the flip-flop circuit 38 is in the "0" state, and the Q output is also in the "0" state. Furthermore, since the input to the inverter circuit 30 is "0", the output is "1", and therefore the oscillation circuit 32 is in a stopped state and the timer 35 does not operate. The temperature of the refrigerator compartment 4 is detected by the thermistor 18, and the comparator 27 operates so that the output of the comparator 27 becomes "1" when the temperature is 0° C. or higher. Both inputs of the AND circuit 29 are "0", and the output is "0". Therefore, the OR circuit 28 is operated by the output of the freezer compartment internal temperature detection circuit 24, and the output of the OR circuit 28 becomes "0" or "1".

When the Q output of the flip-flop circuit 38 is "0", the transistor 40 is off, and the display 41 is off during intense cooling.

When the forced cooling switch 37 is activated and turned on, if the clock input of the flip-flop circuit 38 changes from "0" to "1", a flip-flop operation is performed and the Q output changes from "0" to "1". The forced cooling switch 37 is a switch that is turned on only when activated and turned off immediately. Therefore, the input to the inverter circuit 30 is such that the Q output of the flip-flop circuit 38 is in the "1" state, and the output of the inverter circuit 38 is in the "1" state. ” becomes “0”, the oscillation circuit 32 starts oscillating, a pulse is input to the clock input of the timer 35, and a counting operation is performed. At the same time, both the two inputs of the AND circuit 29 become "1", and the output changes from "0" to "1".

This output is sent to one input of the OR circuit 28,
Since one input of the OR circuit 28 becomes "1" regardless of the output state of the comparator 25 due to the state of the thermistor 17, the output also becomes "1", and the transistor 31 is turned on as described above, and the relay 2
2 is excited, the normally open contact 23 is closed, the electric compressor 21 and the blower 6 are connected to the power supply terminals 19 and 20, and the motor starts and enters forced cooling operation. When the Q output of the flip-flop circuit 38 becomes "1", the transistor 40 is turned on and the strong cooling indicator 41 lights up to indicate that the forced cooling operation is in progress.

Due to the forced cooling operation, the temperature of the freezer compartment 3 decreases,
Even if the thermistor 17 detects that the value is lower than the set value, the output of the OR circuit 28 is "1" since the output of the AND circuit 29 is "1", and the cooling operation continues.

On the other hand, the damper thermostat 16 in the refrigerator compartment 4
The amount of cooling air is adjusted and the temperature is controlled to a predetermined temperature. However, if the cooling operation continues continuously, the temperature will increase between the damper thermostat 16 and the air outlet 14 and between the partition wall 2 between the freezer compartment 3 and the refrigerator compartment 4. If the seal is bad, the cooling air will be gradually sent to the refrigerator compartment 4, and the temperature will drop. When the temperature of the refrigerator compartment 4 becomes 0° C. or lower, the thermistor 18 detects the temperature of the refrigerator compartment 4, and the comparator 27 operates so that the output changes from “1” to “0”. When the output of the comparator 27 becomes “0”, the AND circuit 29
1 input becomes "0", so the output becomes "0". One input of the OR circuit 28 becomes "0". At this time, if the inside of the freezer compartment is sufficiently cooled, the output of the comparator 25 is "0", and the OR circuit 28
Since both inputs are "0", the output becomes "0", transistor 31 is turned off, and relay 2
2 stops operating, the normally open contact 23 is opened, the electric compressor 21 and the blower 6 are disconnected from the power terminals 19 and 20, and the cooling operation is stopped. That is, the temperature in the refrigerator compartment 4 is controlled so as not to drop below 0°C. Since the Q output of the flip-flop circuit 38 is "1", the oscillation circuit 32 continues to oscillate, and the timer 35 continues to count input pulses. As the cooling operation is stopped, the temperature of the refrigerator compartment 4 rises, and when the temperature reaches 1° C. or more, the comparator 27 is activated by the resistance value of the thermistor 18, and the output changes from "0" to "1". AND
The first input of the circuit 29 is the Q output "1" of the flip-flop circuit 38, so when the output of the comparator 27 becomes "1", the output becomes "1" and the OR circuit 2
Since one input of 8 becomes "1", the output becomes "1" and the cooling operation starts again as described above. timer 35
counts the input clock, and as the count progresses, the final stage output, that is, the flip-flop circuit
The output of FF ₇ becomes “0”. When the output of flip-flop circuit FF ₇ becomes “0”, AND circuit 3
When one input of 9 becomes "0", the output changes from "1" to "0". AND circuit 39 goes from “1” to “0”
When the pulse falls, the one-shot circuit 36 outputs one positive pulse in synchronization with the fall of this pulse. The pulse signal from the one-shot circuit 36 sends this signal to the reset terminal of the timer 35 and the reset terminal of the flip-flop circuit 38.
Each will be reset. The counted contents of the timer 35 are all "0". The flip-flop circuit 38 is also reset, the Q output changes from "1" to "0", the transistor 40 changes from the on state to the off state, and the display 41, which is being strongly cooled, is turned off. Similarly, the input of the inverter circuit 30 becomes "0", the output becomes "1", and the oscillation circuit 32
stops oscillation. Since the Q output of the flip-flop circuit 38 becomes "0" for one input of the AND circuit 29, the output also becomes "0", and one input of the OR circuit 28 becomes "0".

Since the freezer compartment is sufficiently cooled during forced cooling, the output of the comparator 25 is "0", and the two inputs of the OR circuit 28 are both "0", the output is "0", and the transistor 31 is turned off. As a result, the electric compressor 21 and the blower 6 stop operating. This ends the forced cooling operation, and thereafter the cooling operation and stop will be repeated based on the output of the comparator 25 which operates based on the temperature of the freezer compartment 3 detected by the thermistor 17 described above.

When the forced cooling switch 37 is operated and turned on again, the forced cooling operation starts as described above, and a display indicating that strong cooling is in progress is also displayed. The forced cooling operation continues during the time safe set by the timer 37, but if the inside of the refrigerator is sufficiently cooled within the time safe and it is desired to stop, the forced cooling switch 37 is activated again. Since the output of the data input of the flip-flop circuit 38 is "0", it operates when the clock input changes from "0" to "1", and the Q output changes from "1" to "0". Therefore, the flip-flop circuit 38
When it becomes "0", as mentioned above, the display 4 during strong cooling
1 goes out, timer 35 turns on one shot circuit 36
The cooling operation is stopped by the output of the AND circuit 29.

In this way, the present invention provides an electric compressor of a cooling system that cools the inside of the refrigerator, a blower that forcibly circulates cold air to the freezer compartment and the refrigerator compartment, and a refrigerator compartment that is installed to reduce the amount of cold air flowing into this compartment. A damper thermostat to adjust, each temperature detection circuit to detect each temperature of the freezer compartment and refrigerator compartment, and a switch to forcibly start and stop the operation of the electric compressor. The electric compressor is controlled by a timer that stops operation after a certain period of time, and a temperature detection circuit in the freezer compartment when the switch is not in cooling operation, and when the switch is in cooling operation, the refrigerator compartment temperature detection circuit detects a temperature below the set value. This system is equipped with a control circuit that uses the temperature detection circuit in the freezing room to stop the operation of the electric motor compressor, and for other cases, uses the timer or switch mentioned above to forcefully stop the operation. Even if the temperature in the refrigerator compartment decreases, the control circuit can prevent the temperature from affecting the refrigerator compartment, allowing preserved foods to be stored well and achieving the original purpose.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a refrigerator employing an embodiment of the device of the present invention, and FIG. 2 is an electric circuit diagram thereof. 6...Blower, 16...Damper thermostat, 21...Electric compressor, 24, 26...Temperature detection circuit, 35...Timer, 37...Forced cooling switch (switch), 42...Forced operation control circuit (control circuit).

Claims (1)

[Claims] 1 Electric compressor of the cooling system that cools the inside of the refrigerator,
A blower that forcibly circulates cold air to the freezer compartment and the refrigerator compartment; a damper thermostat installed in the refrigerator compartment to adjust the amount of cold air flowing into the compartment; and a damper thermostat that controls the temperature of the freezer compartment and refrigerator compartment. a temperature detection circuit for detecting; a switch for forcibly starting and stopping the operation of the electric compressor; a timer that starts operating when the switch starts operating and stops the operation after a certain period of time; The electric compressor is controlled by a temperature detection circuit that detects the temperature in the freezer compartment, and during operation by the switch, the electric compressor is controlled by the temperature detection circuit in the freezer compartment only when the temperature detection circuit in the refrigerator compartment detects a temperature below the set value. A forced cooling operation control device for a forced ventilation refrigerator-freezer, which is equipped with a control circuit that stops the operation of the refrigerator, and forcibly stops other operations using a timer or switch.