JPH01127878A - Refrigerator - Google Patents

Abstract

PURPOSE: To quickly lower a temperature in a freezing chamber after it is defrosted and hence prevent an advance influence to an article stored in the freezing chamber by forcedly changing over cooling operation only for the freezing chamber only for a predetermined time after completion of defrosting operation for a condenser. CONSTITUTION: A defrosting heater 7 is interrupted in power supply thereto, and defrosting operation is completed, and further a timer 35 starts 30 minute timer operation to output a high level signal, and the high level signal is applied to driver circuit 22, 29 through OR circuits 21, 28. Hence electric, power is impressed to a solenoid valve 13 and a compressor 6 irrespective of the states of a refrigeration chamber temperature control section 15 and a freezing chamber temperature control section 23, and hence the operation is forcedly changed over to the state where a refrigerant discharged from the compressor 6 is supplied only to a freezing chamber condenser 4, and hereby cooling operation only for the freezing chamber 2 is achieved. When 30 minutes are elapsed since such cooling operation is started, a low level signal is outputted from the timer 35, and thereafter ordinary cooling operation is achieved with the refrigeration chamber temperature control section 15 and the freezing chamber temperature control section 23.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a refrigerator equipped with a freezer compartment and a refrigerator compartment.

[Technical background of the invention]

For example, a direct cooling type refrigerator equipped with a freezer compartment and a refrigerator compartment has conventionally been configured to control the compressor on and off according to the temperature in the freezer compartment, and when the compressor is driven! When the temperature in the refrigerator compartment rises to a predetermined temperature or higher in B (that is, the temperature in the freezer compartment is above a set value), refrigerant is supplied to both the freezer compartment cooler and the refrigerator compartment cooler.

[Problems with back-feeding technology]

In the conventional refrigerator described above, the drive of the compressor is stopped at an appropriate time to defrost the freezer compartment cooler, but the temperature in the freezer compartment increases due to the defrosting operation. is unavoidable. However, since items such as ice cream or other frozen foods for long-term storage that are easily affected by temperature increases are stored in the freezer compartment, it is important to lower the temperature in the freezer compartment as soon as possible after the defrosting operation is completed. is desirable. However, although the compressor restarts when the defrosting operation ends, if the temperature in the refrigerator room has risen above the predetermined temperature at the end of the defrosting operation, Since refrigerant is supplied to both coolers, the rate of decrease in temperature in the freezer compartment becomes slow, which may adversely affect stored items in the freezer compartment.

[Purpose of the invention]

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a refrigerator that can quickly lower the temperature of the freezer compartment after the defrosting operation of the cooler is completed, thereby eliminating the risk of adversely affecting stored items in the freezer compartment.

[Summary of the invention]

The present invention provides a refrigerator equipped with a freezer compartment and a refrigerator compartment.
This configuration is provided with a temperature guarantee means for forcibly switching to cooling operation only for the freezer compartment for a certain period of time after the defrosting operation of the cooler is completed.

[Embodiments of the invention]

Hereinafter, an embodiment in which the present invention is applied to a direct cooling type refrigerator will be described with reference to the drawings.

In FIG. 1, 1 is a refrigerator body having a freezer compartment 2 and a refrigerator compartment 3, 4 is a freezer compartment cooler disposed around the freezer compartment 2, and 5 is a cooler located at the upper part of the refrigerator compartment 3. 6 is a compressor, 7 is a defrosting heater attached to the freezer compartment cooler 4, 8 is a freezer compartment door, and 9 is a refrigerator compartment door.

FIG. 2 shows a known refrigeration cycle to which the present invention is applied. In this m2 diagram, 10 is a capacitor, 1
1 is a main capillary tube, 12 is an auxiliary capillary tube, 13 is a solenoid valve, and 14 is a bypass capillary tube. and the suction hole 6b as shown in the figure. In such a refrigeration cycle, the solenoid valve 13 is configured to be in a closed state when the power is cut off and to be in an open state when the power is energized.
The solenoid valve 13 exhibits a "first state" in which the refrigerant discharged from the compressor 6 is supplied to both the refrigerator compartment cooler 5 and the freezer compartment cooler 4 when the solenoid valve 13 is in its closed state, and supplies the refrigerant to both the refrigerator compartment cooler 5 and the freezer compartment cooler 4 when it is in its open state. The state is switched to a "second state" in which the liquid is supplied only to the freezer cooler 4 via the bypass capillary tube 14.

Now, FIG. 3 shows only the portions of the electric circuit configuration of the two-temperature refrigerator that are related to the gist of the present invention. In FIG. 3, reference numeral 15 denotes a temperature control unit for the refrigerator compartment whose set temperature TR (having a constant differential) can be changed by a variable resistor 16. When the temperature detected by the thermistor 17 arranged to detect temperature exceeds the upper limit of the set temperature TR, the comparator circuit 18 outputs a high level signal, and the detected temperature falls below the lower limit of the set temperature TR. When this happens, the comparator circuit 18 outputs a low level signal. The output of the comparison circuit 18 is connected to the inverter 19. AND circuit 20. The signal is applied to a drive circuit 22 via an OR circuit 21, and the drive circuit 22 energizes the electromagnetic valve 13 to open it only when receiving a high level signal. Reference numeral 23 denotes a temperature control unit for the freezer compartment whose set temperature TF (having a constant differential) can be changed by a variable resistor 24. When the temperature detected by the arranged thermistor 25 exceeds the upper limit of the set temperature TF, a high level signal is output from the comparator circuit 26,
Further, when the detected temperature becomes equal to or lower than the lower limit of the set temperature TF, the comparison circuit 26 outputs a low level signal. The output of the comparison circuit 26 is an AND circuit 27. The signal is applied to a drive circuit 29 via an OR circuit 28, and this drive circuit 29 supplies current to the compressor 6 to drive it only when receiving a high level signal. Reference numeral 30 denotes a defrosting control unit of the freezer compartment cooler 4, which serves as a temperature detection means for the freezer compartment cooler 4 and is connected to the freezer compartment temperature control unit 2.
It also serves as the thermistor 25 of No. 3, and the thermistor 25
outputs a high level signal from the comparator circuit 31 when the temperature reaches a predetermined defrosting completion temperature, for example, 10° C. or higher;
During periods other than this, the comparator circuit 31 outputs a low level signal. 32 is an R-S flip-flop forming part of the defrosting control section 30, whose reset input terminal R is connected to the output terminal of the comparator circuit 31, and whose set input terminal S is used to start automatic return normally open defrosting. It is connected to the positive power supply terminal +Vcc via the switch 33. Therefore, the R-S flip-flop 32 is set when the defrosting start switch 33 is turned on, and is reset when the comparison circuit 31 outputs a high level signal. And R
The output from the reset output terminal 0 of the -S flip-flop 32 is given to one input terminal of the AND circuit 20.27, and the output from the set output terminal Q thereof is given to the drive circuit 34. , this drive circuit 34
energizes the defrosting heater 7 to generate heat only when receiving a high level signal. Now, 35 is a timer which is a temperature guarantee means, and this timer 35 starts a timer operation for, for example, 30 minutes in response to the output of the 71 level signal from the comparator circuit 31, and also starts a timer operation for, for example, 30 minutes. only outputs a high level signal, and the high level signal is sent to the drive circuit 22 via the OR circuits 21 and 28.
and 29. Note that 36 is a resistor for generating a reference voltage for comparison.

Next, the operation of this embodiment having the above configuration will be explained. now,
During normal operation when the R-S flip-flop 32 is reset, that is, a high level signal is output from its reset output terminal 0, the temperature of the refrigerator compartment cooler 5, that is, the temperature detected by the thermistor 17 is set. Temperature TR
When the temperature of the freezer compartment cooler 4, that is, the temperature detected by the thermistor 25 is above the upper limit of the set temperature TF, a high level signal is output from the comparison circuit 18. When the 1-level signal is being output, the low-level signal inverted by the inverter 19 is input to one input terminal of the AND circuit 20, and the high-level signal is input to both input terminals of the AND circuit 27, respectively. Therefore, a low level signal is output from the AND circuit 20 and given to the drive circuit 22, so that the solenoid valve 13 is closed and switched to the "first state", and a high level signal is output from the AND circuit 28. Since the signal is output and given to the drive circuit 29, the compressor 6 is energized and driven. Therefore, the refrigerant discharged from the compressor 6 is supplied to both the refrigerator compartment cooler 5 and the freezer compartment cooler 4, thereby cooling both the refrigerator compartment 3 and the freezer compartment 2. By such cooling operation, the refrigerator compartment 3
When the internal temperature decreases and the temperature detected by the thermistor 17 becomes below the lower limit of the set temperature TR, a low level signal is output from the comparison circuit 18 and a high level signal is given to the drive circuit 22. Therefore, the solenoid valve 13 is energized and switched to the "second state". Therefore, the refrigerant discharged from the compressor 6 is supplied only to the freezer compartment cooler 4, and the cooling operation of the freezer compartment 2 is continued.

Through this cooling operation, the temperature inside the freezer compartment 2 further decreases, so that the temperature detected by the thermistor 25 reaches the set temperature TF.
When it becomes below the lower limit value, a low level signal is output from the comparator circuit 26, so that the compressor 6 is switched to the "third state" in which the power is cut off and the operation of the refrigeration cycle is stopped. After this, when the temperature detected by the thermistor 25 exceeds the upper limit of the set temperature TF, the drive of the compressor 6 is restarted, and the solenoid valve 13 is closed or opened depending on the temperature detected by the thermistor 17. The same cooling operation as described above is repeated.

Now, when the frost on the freezer compartment cooler 4 has grown to a certain extent due to repeated cooling operations as described above, the defrosting start switch 33 is turned on.

Then, the R-S flip-flop 32 is set,
Since a high level signal is output from the set output terminal Q and a low level signal is output from the reset output terminal Q, the high level signal is given to the drive circuit 34 and energization to the defrosting heater 7 is started at the same time. , AND circuit 2
The output of 0.27 is maintained at a low level signal, and the temperature control section 15 for the refrigerator compartment and the temperature control section 2 for the freezer compartment
Power to the compressor 6 and the solenoid valve 13 is cut off regardless of the respective states of 3. In this manner, the defrosting operation of the freezer compartment cooler 4 is started in which the defrosting heater 7 generates heat while the compressor 6 is stopped. As the defrosting operation progresses, when all the frost on the freezer compartment cooler 4 is melted and the temperature detected by the thermistor 25 becomes equal to or higher than the predetermined defrosting completion temperature, a comparison circuit 31 in the defrosting control section 30 A high level signal is output. Then, R-
Since the S flip-flop 32 is reset, the defrosting heater 7 is cut off and the defrosting operation is terminated, and the timer 35 starts a 30-minute timer operation and outputs a high level signal. This high level signal is applied to drive circuit 22.29 via OR circuit 21.28. Therefore, the electromagnetic valve 13 and the compressor 6 are energized regardless of the respective states of the refrigerator temperature control section 15 and the freezer temperature control section 23, and in this way, the air is discharged from the compressor 6. The refrigerant is forcibly switched to the "second state" in which the refrigerant is supplied only to the freezer compartment cooler 4, and cooling operation of only the freezer compartment 2 is performed. When 30 minutes have passed since such cooling operation started, timer 35
When the timer operation ends, a low level signal is output from the timer 35, and from this point on, the solenoid valve 13 and the compressor 6 are controlled by the refrigerator temperature control section 15 and the freezer temperature control section 23. As a result, normal cooling operation can be performed.

In the above embodiment, the present invention was applied to a direct cooling type refrigerator, but it goes without saying that the present invention may also be applied to a fan cool type refrigerator.

〔Effect of the invention〕

According to the present invention, as is clear from the above explanation, since the structure is configured such that only the freezing compartment is forcibly cooled for a certain period of time after the completion of the defrosting operation of the cooler, It is possible to bring about the excellent effect that the room temperature can be quickly lowered and there is no possibility that the stored items in the freezing room will be adversely affected.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a vertical sectional side view, FIG. 2 is a diagram showing a refrigeration cycle, and FIG. 3 is an electric circuit diagram. In the figure, 2 is a freezer compartment, 3 is a refrigerator compartment, 4 is a cooler for the freezer compartment,
Reference numeral 5 designates a cooler for the refrigerator compartment, 6 a compressor, 7 a defrosting heater, and 35 a timer (temperature control means). 1st Figure 112Figure 11!3 Figure

Claims (1)

[Claims] 1. Selectively select between a first state in which both the freezer compartment and the refrigerator compartment are cooled, a second state in which only the freezer compartment is cooled, and a third state in which the compressor is stopped, depending on the temperature in the freezer compartment and the refrigerator compartment. In the device configured to be able to switch to the second state and to perform defrosting operation of the cooler at a predetermined time, temperature guarantee means is provided for forcibly switching to the second state for a certain period of time after the defrosting operation is completed. A refrigerator featuring