JPS6029574A - Refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a refrigerator that cools a freezer compartment with both a fan-cool cooler and a direct-cool cooler.

[Technical background of the invention]

In this type of refrigerator, a fan device that circulates air within the freezer compartment is driven and stopped in synchronization with supply and cutoff of refrigerant to a fan cooling cooler. Further, defrosting of the freezer compartment is carried out by heating the fan cooling cooler with, for example, a defrosting heater while the supply of refrigerant to the cooler is cut off.

[Problems with background technology]

However, in the above configuration, after defrosting the fan cooling cooler, when refrigerant is resupplied to the auxiliary cooler and the fan cooling cooler, the fan cooling cooler is installed due to residual heat from defrosting. The temperature of the circulation path is higher than that of the inside of the refrigerator, and the temperature of the surface of the auxiliary cooler reaches a lower temperature earlier than the surface temperature of the inside of the circulation path. Conventionally, this type of fan-cooled refrigerator has not been equipped with a defrost damper to isolate the freezer compartment and the circulation room during defrosting, and for this reason, the circulation path and the freezer compartment where the auxiliary cooler is installed are not connected. Convection occurs due to the temperature difference between the refrigerator and the refrigerator, and air from the circulation path during defrosting, which is relatively high in temperature, flows into the refrigerator, increasing the temperature in the freezer and being contained in the auxiliary cooler in the freezer. Moisture cools and solidifies, forming frost. Therefore, even though the defrosting operation of the freezer compartment has been completed, there has been a problem in that the auxiliary cooler inside the freezer compartment is frosted.

[Purpose of the invention]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a refrigerator that can prevent adverse thermal effects in the freezer compartment after defrosting the freezer compartment.

[Summary of the invention]

The present invention has a damper device that closes during defrosting operation, and a first damper device in a circulation path that circulates air in the freezing chamber using a fan device.
a cooler, and a second cooler is arranged in the freezing chamber, and after the defrosting operation of the first cooler is completed, the fan device is stopped and the damper device is closed. A refrigerant is supplied to both the first and second coolers in the above-mentioned state, thereby cooling both coolers without causing air convection in the freezing chamber and absorbing residual heat from the first cooler during defrosting. At the same time, the inside of the freezer compartment is cooled by the second cooler, and then the fan device is driven and the damper device is opened, and refrigerant is supplied to both coolers, so that the cold air produced by the first cooler is supplied. It is characterized in that it is circulated within the freezing chamber and the stored items in the freezing chamber are directly cooled by the second cooler.

(Embodiment of the Invention) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, which shows an outline of a refrigerator, a heat insulating box 1 has a refrigerator compartment 2 and a freezing compartment 3 that is thermally independent from the refrigerator compartment 2. It can be opened and closed freely. A refrigerator compartment cooler 4 is arranged in the refrigerator compartment 2, and an auxiliary cooler 5, which is a second cooler, is arranged in the freezer compartment 3 to directly cool food. Further, an air passage chamber 6 is formed extending to the back of the freezer compartment 3 and under the floor, and forming a part of a circulation path for circulating the air in the freezer compartment 3. Reference numeral 7 denotes a main cooler for the freezer compartment, which is a first cooler, and is disposed within the air passage chamber 6 and cools the interior of the freezer compartment 3 in cooperation with the auxiliary cooler 5. 8 is a damper device disposed above the main cooler 7 for the freezer compartment in the air passage chamber 6 to open and close the air passage chamber 6; 9 is a damper device having a fan motor 9a and disposed above the damper device 8; This is a fan device that circulates the air in the freezer compartment 3 through the air passage chamber 6. The refrigeration cycle of this refrigerator is constructed as shown in FIG. That is, between the discharge port and the suction port of the rotary compressor 10, a condenser 11, a first control valve 12,
It forms a refrigerant flow path consisting of the refrigerator compartment cooler 4, the freezer compartment main cooler 7, the accumulator 13, and the check valve 14, and is parallel to the flow path consisting of the first control valve 12 and the refrigerator compartment cooler 4. A flow path consisting of a second control valve 15 and an auxiliary cooler 5 is connected to. Note that 16a to 16e are capillary tubes. FIG. 3 shows the circuit configuration for controlling this refrigeration cycle. In FIG. 3, 17 is a control section which receives temperature information from a temperature detection unit 18 and gives a control signal to a drive unit 19, so that this drive unit 19 controls the first control valve 12 and the second control valve. valve 15
The transistors 20a and 20b are used to turn on and off the refrigeration unit 5, and the defrosting heater 21, damper drive heater 22, fan motor 9a and compressor 1 attached to the room main cooler 7 are controlled.
The compressor motor 23 that drives the motor 0 is controlled to be turned on and off by relay contacts 24 to 27, respectively. Here, the tamper-driven heater 22 connects the damper device 8 that opens and closes the discharge port of the ventilation passage 6 into the freezer compartment 3 through its bellows portion 28.
This is for operating the heat sensitive part 28a in the opening direction by heating the heat sensitive part 28a including the heat sensitive part 28a. In addition, in other parts of this Fig. 3, reference numeral 29 denotes an operation unit for adjusting the temperature of the freezer compartment and refrigerator compartment, a quick freezing switch, etc., and an operation and display unit that constitutes a display unit for displaying operation display, temperature status display, etc. In the unit, 30 is an interior light, 31 is a door switch, and 32 is a plug terminal. FIG. 4 shows a specific circuit of the temperature detection unit 18. In this FIG. 4, 33 is a refrigerator vortex detection element, 34 is a refrigerator room temperature detection element,
35 is a defrosting completion detection element (temperature detection), 36 is a freezing room temperature detection element, and among these, the former three elements 33 and 34
．． The signals due to the resistance changes of 35 are sent to the voltage dividing resistor circuit 33 by the -〇-] amparators 37, 38, and 39, respectively.
Reference value Va set by a, 34a, 35a
, Vb, and VC, and output the control unit as a refrigerator compartment cooler vortex signal S1, a refrigerator compartment air temperature signal S2, and a defrosting completion signal S4]
7, and the resistance change of the freezing room temperature detection element 36 is compared with a reference mvd set by the voltage dividing resistor circuit 36a by a comparator 40, and is provided to the control section 17 as a freezing room temperature signal S3. In particular, the comparator 40 includes a hysteresis loop 40 that includes a diode.
a, and the temperature value of the refrigerator room temperature (air temperature) signal S3 is made different between the rise and fall processes of the internal temperature, and a predetermined temperature is set between the stop temperature and the restart temperature of the compressor 10 in both cases. I try to make a difference.

Next, the operation of the above configuration (also shown in the flowcharts of FIGS. 5 and 6) will be explained. This explanation should make the configuration of the refrigeration cycle control system even clearer.

(I) Normal operation Assuming that the temperatures in the refrigerator compartment 2 and freezer compartment 3 are now higher than the set temperature, the control unit 17 detects this by transmitting the refrigerator compartment cooler vortex signal S1, which is constantly received from the temperature detection unit 18, and the refrigerator compartment cooler vortex signal S1. Judging from the room air temperature signal S2 and the frozen room temperature signal S3, the compressor 10 was driven by the compressor motor 23, the fan motor 9a was also energized, and the first control valve 12 was opened and the second control valve 15 was closed. cooling operation continues. That is, in this state, the compressor 10
The refrigerant gas discharged from the refrigerant gas is liquefied by the condenser 11 and is supplied to the refrigerator compartment cooler 4 and the freezer compartment main cooler 7 through the first control valve 12 to cool the inside of the refrigerator compartment 2 and the freezer compartment 3. . In this case, the inside of the refrigerator compartment 2 is cooled by natural convection, and the inside of the freezer compartment 3 is cooled by forced circulation of cool air from the main cooler 7 for the freezer compartment (during this time,
Damper unit @8 is open). When the temperature of the refrigerator compartment 2 drops to the set temperature, a switching operation is performed to close the first control valve 12 and open the second control valve 15 based on the refrigerator compartment air temperature signal S2 obtained by the refrigerator room temperature detection element 34. is switched to the supply state to the auxiliary cooler 5 and the main cooler 7 for the freezer compartment. When the temperature of the freezer compartment 3 drops to the set temperature in this state, the operation of the compressor 10 is stopped based on the freezer room temperature signal S3 obtained by the freezer room temperature detection element 36. During such a stop period of the compressor 10, the first control valve 1
2. Both of the second control valves 15 are kept open, so that the condenser 11 immediately after the compressor 10 is stopped.
This prevents superheated refrigerant gas staying in the cooler from leaking to the cooler side and heating it, and improves the efficiency of restarting the compressor 10 by maintaining the refrigerant in the condenser 11 in a high condensing pressure state. If the temperature of the freezing chamber 3 rises above the set range while the compressor 10 is stopped, the compressor 10 is restarted based on the freezing room temperature signal S3 at this time.

(JT) Prevention of reduction in refrigerator compartment cooling capacity The first control valve 12 opens while the compressor 10 is operating, and the state in which refrigerant is supplied to both the refrigerator compartment cooler 4 and the freezer compartment main cooler 7 continues. If this continues for a long period of time, for example 10 hours, the timer determines this and closes the first control valve 12, while opening the second control valve 15 to stop the refrigerant from flowing to the refrigerator compartment cooler 4. The supply is stopped, and the frost adhering to the refrigerator compartment cooler 4 is removed by natural melting. As a result, refrigerant is continuously supplied to the refrigerator compartment cooler 4 for a long period of time, and the frost does not lose the opportunity to dissolve naturally. Therefore, a large amount of frost adheres to the refrigerator compartment cooler 4, which improves the cooling efficiency in the refrigerator. This prevents the situation from decreasing.

(nl) Preventing cooling stoppage in the refrigerator compartment If 30 minutes have passed since the temperature in the refrigerator compartment 2 rose to the cooling start temperature, for example, 3.5°C while the compressor 10 is stopped, the compressor 10 and the compressor motor 23
is forcibly driven without depending on the frozen room temperature signal S3 from the frozen room temperature detection element 36. Such forced restart of the compressor 10 is performed by a timer that monitors the refrigerator compartment cooler vortex signal S1 from the refrigerator compartment cooling type temperature detection element 33. As a result, it is possible to prevent the refrigerator compartment 2 from being left in a non-operating state for a long period of time with a high load inside the refrigerator compartment 2 and a high internal floor.

(IV) Rapid freezing operation In this operation, the rapid freezing timer is started manually and the compressor 10 is driven, while the first control valve 12 is closed and the second control valve 15 is opened, and the auxiliary cooler 5 and This is an operation in which the refrigerant supply to the main cooler 7 for the freezer compartment is forcibly continued for the set time, thereby rapidly cooling the inside of the freezer compartment 3.

Then, when the set time of the quick freezing timer elapses, the first control valve 12 opens and the second control valve 15 closes to forcibly perform a channel switching operation for the refrigerator compartment cooler 4 and the freezer compartment cooler 4 and the freezer compartment cooler 4. The refrigerant is supplied to the main cooler 7, and this is continued until a cooling stop command is given by the refrigerating room air temperature signal S2 from the refrigerating room temperature detection element 34. In this way, the temperature rise in the refrigerator compartment 2 during the rapid freezing operation period of the freezer compartment 3 is compensated for.

(V) Defrosting operation The defrosting operation of the main cooler 7 for the freezer compartment is performed as follows. That is, the defrost monitoring timer integrates the operating time of the compressor 10, and outputs a defrost start command signal when the operating time of the compressor 10 reaches a set time, for example, 48 hours. This command causes a pre-defrost forced cooling operation to be performed.

(A> Forced cooling operation before defrosting) The compressor motor 23 and fan device 9 are driven and the first control valve 12 is forcibly opened based on the defrosting start command to cool the refrigerator compartment cooler 4 and the freezing compartment. Refrigerant is supplied to the main cooler 7.

This state continues until the first control valve 12 is closed in response to the refrigerating room air temperature signal S2 from the refrigerating room temperature detection element 34, whereby the refrigerating room 2 is forcedly cooled. Then, when the first control valve 12 is closed and the second control valve 15 is opened in response to the refrigerator compartment air temperature signal S2, the refrigerant is forcibly supplied to the auxiliary cooler 5 and the main cooler 7 for the freezer compartment. This state is maintained for a certain period of time by a dedicated timer, for example, 15 minutes.
Continue for a minute. And with the passage of this time, the compressor 10
The drive of the first control valve 12. is stopped. Second control valve 1
5 is brought into a closed state, while the damper device 8 is brought into a closing operation. Closing of the damper device 8 is performed by energizing the damper drive heater 22 to expand the bellows portion 28. In this way, the water vapor filling the enclosed chamber 6 during the defrosting operation is discharged into the freezing chamber 3 due to the convection effect due to the temperature difference with the freezing chamber 3, and freezes and accumulates on the surface of the auxiliary cooler 5. prevent. When the damper device 8 is closed in this manner, the defrosting heater 21 is energized, and the actual defrosting operation for melting and removing the frost adhering to the main cooler 7 for the freezer compartment is started. When defrosting is completed, the surface temperature of the main cooler 7 for the freezer compartment rises suddenly, and therefore, the control unit 17 determines this based on the defrosting completion signal S4 obtained by the defrosting completion detection element 35, and turns on the defrosting heater. At the same time, the defrosting completion incidental operation is performed.

(B) Defrosting Completion Ancillary Operation This defrosting completion ancillary operation includes a water droplet removal operation and a forced storage temperature recovery operation.

First, after the power to the defrosting heater 21 is cut off, the damper device 8 is continuously kept open and the compressor 10 is kept stopped for a predetermined short period of time, for example, 5 minutes, using a timer 13. During this period, water droplets adhering to the surface of the main cooler 7 for the freezer compartment due to melting of frost are allowed to flow down naturally, thereby preventing these water droplets from freezing when the cooling operation is started.

Now, after the water droplet removal operation is completed by the timer, the forced storage temperature recovery operation is performed as follows. That is, the compressor 10 is forcibly driven as the set time of the water droplet removal timer elapses, and the second control valve 1 is
5 is opened and the defrosting residual heat absorption operation is forcibly performed for a predetermined period of time, for example, 10 minutes, while supplying refrigerant only to the auxiliary cooler 5 and the main cooler 7 for the freezer compartment. The damper device 8 is kept in a closed state, and the fan device 9 is also kept in a stopped state. In this way, the main cooler 7 for the freezer compartment and the auxiliary cooler 5 are cooled while the air circulation inside the freezer compartment 3 is stopped, so the inside of the freezer compartment 3 is cooled by the auxiliary cooler 5, and at the same time The residual heat of the main cooler 7 for the freezer compartment during defrosting is absorbed 14- and the cooler 7 itself and the inside of the air passage chamber 6 are again cooled down to a sufficiently low temperature. In this way, if the cold 7JI operation is restarted at the same time as the defrosting is completed, and the damper device 8 is opened to drive the fan device 9, the defrosting operation trapped in the main cooler 7 for the freezer compartment itself and the air passage chamber 6 will occur. To prevent the inconvenience that water vapor or residual heat, that is, warm air, is immediately blown out into the freezer compartment 3.

Next, after such a defrosting residual heat absorption operation, Imamaro opens the damper device 8 again using the timer and supplies refrigerant only to the auxiliary cooler 5 and the main cooler 7 for the freezer compartment while driving the fan device 9. Perform forced operation for about 20 minutes. As a result, the inside of the freezer compartment 3 is strongly cooled by the circulation of cold air generated by the main cooler 7 for the freezer compartment in addition to the auxiliary cooler 5, so the tendency of temperature rise during defrosting is corrected and the freezer compartment The temperature inside 3 quickly drops to about the set temperature. When this 20 minute period has elapsed, the subsequent control operation is shifted to normal operation based on the freezer compartment cooling type temperature signal S3 from the freezer room temperature detection element 36.

(Vl) Priority relationship between rapid freezing and defrosting operations In actual use, a rapid freezing command may be issued during the defrosting cycle (meaning that includes related operations before and after the actual frost melting operation),
Or, the opposite may occur, and the priority relationship in that case will be described below.

If the command for the rapid freezing operation is received during the defrosting completion incidental operation after the defrosting command has already been generated, or after the defrosting residual heat absorption operation is completed during the defrosting completion incidental operation, the control unit 17 performs the rapid freezing operation. is given priority, and the subsequent operations of the defrosting cycle are stopped, and the state with the defrosting command is resumed.

On the other hand, if the command for fast freezing operation is received between the end of the defrosting forced cooling operation of the defrosting cycle and the end of the defrosting residual heat absorption operation, the defrosting operation is given priority. Let it continue.

In the above embodiment, in order to detect the refrigerator room temperature, the air temperature and the temperature of the cooler itself are detected, and these detection signals are selected and used depending on the control purpose. It is also possible to handle only the refrigeration room temperature signal as the refrigerating room temperature signal.

〔Effect of the invention〕

As described above, the present invention stops the fan device and closes the damper device of the circulation path after defrosting the first fan cooler for cooling the freezer compartment. Since the refrigerant is supplied to the second cooler for direct cooling, the residual heat of the first cooler due to the defrosting operation can be absorbed and this can be prevented from entering the freezer compartment. Furthermore, since the fan device is driven and the damper device is opened after that to supply refrigerant to the first and second coolers, the inside of the freezer compartment is made more powerful by both coolers. Overall, the freezing chamber can be cooled rapidly after defrosting, and its temperature can be recovered quickly.

[Brief explanation of drawings]

The drawings relate to an embodiment of the present invention, in which Fig. 1 is a schematic vertical side view of a refrigerator, Fig. 2 is a connection diagram of a refrigeration cycle, Fig. 3 is an explanatory diagram of the configuration of a control circuit, and Fig. 4 is a temperature diagram. The wiring diagram of the detection unit, FIG. 5 and FIG. 17-6 are flowcharts. In the figure, 2 is a refrigerator compartment, 3 is a freezer compartment, 4 is a cooler for the refrigerator compartment,
5 is an auxiliary cooler (second cooler), 6 is an air passage chamber (circulation path), 7 is a main cooler for the freezer compartment (first cooler), 8 is a damper device, 9 is a fan device, 10 is a compressor. Applicant Tokyo Shibaura Electric Co., Ltd. = 18- WA 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. A first cooler is provided in a circulation path that has a damper device that closes during defrosting operation and circulates air in the freezing chamber using a fan device, and a second cooler is disposed within the freezing chamber. After the defrosting operation of the first cooler is completed, refrigerant is supplied to both the first and second coolers with the fan device stopped and the damper device closed, and then the fan A refrigerator characterized in that the refrigerant is supplied to both the first and second coolers when the device is driven and the damper device is opened.