JPH0435667B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a refrigerator equipped with a freezing compartment and a refrigerating 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 perform on/off control of a compressor depending on the temperature in the freezer compartment, and when the compressor is driven (i.e., the temperature in the freezer compartment When the temperature in the refrigerator compartment rises to a predetermined temperature or higher in a state where the temperature is higher than a set value, refrigerant is supplied to both the freezer compartment cooler and the refrigerator compartment cooler.

[Problems with background technology]

In the refrigerator with the conventional configuration 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 rises due to the defrosting operation. is unavoidable. However, because ice cream and other frozen foods for long-term storage are stored in the freezer compartment, items that are likely to be adversely affected by temperature rises,
It is desirable to lower the temperature inside the freezer as quickly as possible after the defrosting operation ends. 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, the compressor 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 is a refrigerator equipped with a freezer compartment and a refrigerator compartment, in which after the defrosting operation of the cooler is completed, cooling operation of only the freezing compartment is forcibly performed for a certain period of time set in a timer means. .

[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 door for the freezer compartment, and 9 is a door for the refrigerator compartment.

FIG. 2 shows a known refrigeration cycle to which the present invention is applied. In this Figure 2, 10 is a capacitor, 11 is a main capillary tube, and 12 is a capacitor.
is the auxiliary capillary tube, 13 is the solenoid valve, 14
is a bypass capillary tube, which is connected between the discharge port and the suction port of the compressor 6, together with the freezer compartment cooler 4 and the refrigerator compartment cooler 5, as shown. 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 turned on. It exhibits a "first state" in which refrigerant is supplied to both the cooler 5 and the freezer cooler 4, and a "first state" in which refrigerant is supplied only to the freezer cooler 4 via the bypass capillary tube 14 when the refrigerant is in the open state. It is designed to switch to the second state.

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 this Fig. 3, 15 is the set temperature TR (with a certain differential).
is a temperature control unit for the refrigerator compartment that can be changed by a variable resistor 16, and this is a temperature control unit for the refrigerator compartment that can be changed by a variable resistor 16, and this is such that the temperature detected by the thermistor 17 arranged to detect the temperature of the refrigerator compartment cooler 5 and the temperature inside the refrigerator compartment 3 is equal to the set temperature TR. When the detected temperature exceeds the upper limit value, the comparison circuit 18 outputs a high level signal, and when the detected temperature falls below the lower limit value of the set temperature TR, the comparison circuit 18 outputs a low level signal. The output of the comparison circuit 18 is connected to an inverter 19, an AND circuit 20, and a holding means.
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. 23, whose set temperature TF (with a certain differential) is variable resistor 2
4, this is a temperature control unit for the freezer compartment that can be changed by the temperature of the cooler 4 for the freezer compartment, and the temperature detected by the thermistor 25 arranged to detect the temperature inside the freezer compartment 2 exceeds the upper limit of the set temperature TF. When the voltage is exceeded, the comparator circuit 26 outputs a high level signal,
Moreover, when the detected temperature becomes below 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 the AND circuit 2
7. The signal is supplied to a drive circuit 29 via an OR circuit 28 serving as a holding means, and this drive circuit 29 applies current to the compressor 6 to drive it only when receiving a high level signal. 30
is a defrosting control unit of the freezer compartment cooler 4, which also serves as the thermistor 25 of the freezer compartment temperature control unit 23 as a temperature detection means of the freezer compartment cooler 4, and the temperature of the thermistor 25 is When the defrosting completion temperature reaches a predetermined defrosting completion temperature, for example, 10°C or higher, a high level signal as a defrosting completion signal is output from the comparison circuit 31 serving as a detection means, and a low level signal is output from the comparison circuit 31 during other periods. Output. 32 is an R-S flip-flop forming a part of the defrosting control section 30, and its reset input terminal R is connected to the comparison circuit 31.
The set input terminal S is connected to the positive power supply terminal +Vcc via an automatic reset normally open defrosting start 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. The output from the reset output terminal of the R-S flip-flop 32 is as described above.
It is applied to one input terminal of each of the AND circuits 20 and 27, and the output from its set output terminal Q is applied to a drive circuit 34, and this drive circuit 34 operates as described above only when receiving a high level signal. The defrosting heater 7 is energized to generate heat. Now, 35 is a timer, and this timer 35 receives a high level signal when it is output from the comparator circuit 31 and starts a timer operation for a certain period of time, for example, 30 minutes, and only during the timer operation period. A high level signal as a forced operation command signal is output, and the high level signal is applied to drive circuits 22 and 29 via OR circuits 21 and 28.
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 in which the R-S flip-flop 32 is reset, that is, a high level signal is output from its reset output terminal, the temperature of the refrigerator compartment cooler 5, that is, the thermistor 17
A high level signal is output from the comparator circuit 18 when the temperature detected by the thermistor 25 is higher than the upper limit of the set temperature TR, and the temperature of the freezer compartment cooler 4, that is, the temperature detected by the thermistor 25 is higher than the upper limit of the set temperature TF. When a high level signal is also output from the comparator circuit 26, a low level signal inverted by the inverter 19 is input to one input terminal of the AND circuit 20, and a high level signal is input to both input terminals of the AND circuit 27, respectively. A signal is input. Therefore, a low level signal is output from the AND circuit 20 and given to the drive circuit 22, so 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 outputted 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, and both the refrigerator compartment 3 and the freezer compartment 2 are cooled.
When the temperature inside the refrigerator compartment 3 decreases due to such cooling operation and the temperature detected by the thermistor 17 becomes equal to or lower than the lower limit of the set temperature TR, a low level signal is output from the comparator circuit and sent to the drive circuit 22. Since a high level signal is given to the solenoid valve 13, 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. When the temperature inside the freezer compartment 2 further decreases due to such cooling operation, and the temperature detected by the thermistor 25 becomes equal to or lower than the lower limit of the set temperature TF, a low level signal is output from the comparison circuit 26, so that the compressor 6 The operation of the refrigeration cycle is stopped by switching to the "third state" in which the refrigeration cycle is stopped due to power cut. 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 grows to a certain level or more as a result of repeated cooling operations as described above, the defrosting start switch 33 is turned on. Then, the R-S flip-flop 32 is set, and its set output terminal Q outputs a high level signal, and its reset output terminal outputs a low level signal, so that a high level signal is applied to the drive circuit 34. At the same time as the defrosting heater 7 starts to be energized, AND
The outputs of the circuits 20 and 27 are held at low level signals, and the compressor 6 and the solenoid valve 13 are cut off regardless of the respective states of the refrigerator temperature control section 15 and the freezer temperature control section 23. will be done. In this way, 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, the comparison circuit in the defrosting control section 30 31 outputs a high level signal as a defrosting end signal. Then, the R-S flip-flop 32 is reset, so the defrosting heater 7 is cut off and the defrosting operation is terminated, and the timer 35 starts a 30 minute timer operation and sends a high level signal to issue a forced operation command. Now output as a signal, this high level signal is output to OR circuit 2.
1 and 28 to drive circuits 22 and 29. 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 state is forcibly switched to the "second state" in which 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 from the start of such cooling operation, the timer operation of the timer 35 ends and a low level signal is output from the timer 35, and from then on, the temperature control unit 15 for the refrigerator compartment and The solenoid valve 13 and the compressor 6 are now controlled by the freezer compartment temperature control section 23, and normal cooling operation is then 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 Fancool 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 end of the defrosting operation of the cooler, It is possible to quickly lower the temperature in the freezer compartment, and there is no possibility that the stored items in the freezer compartment will be adversely affected, which is an excellent effect.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a vertical sectional side view, FIG. 2 is a diagram showing a refrigeration cycle,
FIG. 3 is an electrical circuit diagram. In the figure, 2 is a freezer compartment, 3 is a refrigerator compartment, 4 is a cooler for the freezer compartment, 5 is a cooler for the refrigerator compartment, 6 is a compressor, 7 is a defrosting heater, 21 and 28 are OR circuits (holding means), 31 is a comparison circuit (detection means), 35
is a timer.

Claims (1)

[Claims] 1. Selective switching between a first state that cools both the freezer compartment and the refrigerator compartment, a second state that cools only the freezer compartment, and a third state that stops the compressor, depending on the temperature in the freezer compartment and the refrigerator compartment. and is configured to perform a defrosting operation of the cooler at a predetermined time, a detecting means for detecting when the defrosting operation is completed and outputting a defrosting end signal; A timer that is configured to perform a timer operation for a certain period of time when a defrosting end signal is output from the means and outputs a forced operation command signal only during the timer operation period, and a timer that outputs the forced operation command signal from the timer. A refrigerator characterized in that a holding means is provided for maintaining the state switched to the second state during the period.