JPS6029577A - 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 provides a refrigerator that has a refrigerator compartment and a freezer compartment with different set temperatures, and has a function of cooling the freezer compartment by direct cooling and indirect cooling by forced circulation of cold air. Regarding.

[Technical background of the invention and its problems]

Traditionally, refrigerators have a direct-cooling type freezer structure in which the inner box for the freezer compartment is formed by the cooler itself, or those with a direct cooling type freezer structure in which the inner box for the freezer compartment is divided into a freezer compartment and an air duct room and the freezer is stored in the air duct compartment. There is a cold air circulation type that includes a room cooler and a fan device that sends cold air into the freezer compartment. Comparing these performances, in a direct cooling type freezer, the cooling rate of food placed on the room wall is fast, but the cooling rate of food placed on a shelf or the like suspended from the cooling wall is slow. On the other hand, compared to the direct cooling type, the food cooling rate in the cold air circulation type is faster for food suspended in the air, but slower for food placed on the chamber wall. In addition, in both the direct cooling type and cold air circulation type, defrosting of the freezer compartment cooler is performed by heating with a heater, but the temperature inside the freezing compartment may rise abnormally due to the thermal effect. There are problems such as storage.

(Object of the Invention) The present invention was made to eliminate these drawbacks, and its purpose is to quickly cool food in the freezer regardless of where it is stored, and to reduce the temperature inside the freezer during defrosting. To provide a refrigerator that can prevent abnormal temperature rise.

[Summary of the invention]

The refrigerator of the present invention has a freezer compartment that is thermally independent from the refrigerator compartment, and has an auxiliary cooler that directly cools food placed in the freezer compartment and a fan that cools the air that is forcibly circulated to produce cold air. A cooler for the freezer compartment consisting of a main cooler is installed, which allows food in the freezer compartment to be quickly cooled regardless of where it is stored. This is an attempt to forcefully cool the room to prevent abnormal temperature rises.

[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 freezer compartment 3 that is thermally independent from the refrigerator compartment 2, each having a front opening with Fi2a and Fi3a.
It can be opened and closed freely. A refrigerator compartment cooler 4 is arranged in the refrigerator compartment 2, and an auxiliary cooler 5 is arranged in the freezer compartment 3 to directly cool food. In addition, an air passage chamber 6 is formed across the back of the freezer compartment 3 and under the floor, and a main cooler 7 for the freezer compartment, which cooperates with the auxiliary cooler 5 to constitute a cooler for the freezer compartment, is disposed in this air passage chamber 6. 8 drives a fan 9 to circulate cold air generated by the main cooler 7 for the freezer compartment through the interior of the freezer compartment 3. This refrigerator has a second freezing cycle.
The configuration is as shown in the figure. That is, between the discharge port and the suction port of the rotary compressor 10, there are a condenser 11, a first control valve 12, a cooler 4 for the refrigerator compartment, a main cooler 7 for the freezer compartment, an accumulator 13, and a check valve. 14, and a flow path consisting of a second control valve 15 and an auxiliary cooler 5 is connected in parallel to the flow path consisting of the first control valve 12 and the refrigerator compartment cooler 4. . Furthermore, 16a
16e to 16e are cabillary rich coves. FIG. 3 shows a 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 12. The control valve 15 of the transistor 20a
, 20b, and also relay the compressor motor 23 that drives the defrosting heater 21, damper drive heater 22, fan motor 8, and compressor 10 attached to the main cooler 7 for the freezer compartment. Contacts 24 to 27
Power on/off is controlled by Here, the tambour-driven heater 22 is used to move the damper 28, which opens and closes the discharge port of the air passage chamber 6 into the freezer compartment 3, in the opening direction by heating the heat-sensitive section 28b including the bell-oze section 28a. It is something. In addition, in other parts of this Fig. 3, reference numeral 29 indicates operation parts and operation displays such as temperature control and rapid freezing switch for the freezer and refrigerator compartments;
An operation and display unit constituting a display section for displaying temperature status, etc., 30 is an interior display, 31 is a door switch,
32 is a plug-in terminal. FIG. 4 shows a specific circuit of the temperature detection unit 18. In 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), and 36 is a refrigeration room temperature detection element.
are freezing room temperature detection elements, and signals due to resistance changes of the former three elements 33, 34, and 35 are sent to voltage dividing resistor circuits 33a and 3 by comparators 37 and 38, and 39, respectively.
Reference values Va and Vb set by 4a and 35a
, Vc, the refrigerator compartment cooler dry signal SIN, refrigerator compartment air temperature signal 8t, and defrost completion signal S4 are provided to the control unit 17.The resistance change of the refrigerator room temperature detection element 36 is detected by the comparator 40 and sent to the voltage dividing resistor circuit. It is compared with a reference value Vd set by 36a and given to the control unit 17 as a frozen room temperature signal S3. In particular, when the comparator 40 includes a diode, it changes the steresis loop 6-/IOa, so that the temperature value of the frozen room temperature (air temperature) signal S3 is different between the rising and falling stages of the internal temperature, so that the compressor 10 A predetermined temperature difference is provided between the shutdown temperature and the restart temperature.

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 8 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 refrigerant gas discharged from the compressor 10 is liquefied by the condenser 11 and passes through the first control circuit, that is, the first control valve 12, to the refrigerator compartment cooler 4 and the freezer compartment main cooler 7. The inside of the refrigerator compartment 2 and the freezer compartment 3 is cooled by supplying it. 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 freezer cooler 7 by the fan 9 (during this time, the damper 28 is open). When the temperature of the refrigerator compartment 2 drops to the set temperature, the first control valve 1 is activated based on the refrigerator compartment air temperature signal S2 obtained by the refrigerator room temperature detection element 34.
2 is closed and the second control valve 15 is opened, thereby switching the refrigerant supply state to the second control circuit, that is, the auxiliary cooler 5 and the main cooler 7 for the freezer compartment. In this state, when the temperature of the freezing compartment 3 drops to the set temperature, the freezing room temperature detection element 3
The operation of the compressor 10 is stopped based on the frozen room temperature signal S3 obtained in step 6. During such a stop period of the compressor 10, the first control valve 12. Second control valve 15
are kept open, thereby preventing the high-temperature refrigerant gas remaining in the condenser 11 from leaking to the cooler side and heating it immediately after the compressor 0 stops, and also preventing the condenser 11 from heating up. The efficiency of restarting the compressor 10 is improved by maintaining the refrigerant at a high condensing pressure state.

While the compressor 10 is stopped, the freezer compartment 3
If the temperature rises above the set range, the compressor 10 is restarted based on the frozen room temperature signal S3 at this time.

(If> Prevention of reduction in refrigerator compartment cooling capacity) If the first control valve 12 opens while the compressor 10 is operating and refrigerant is continuously supplied to both the refrigerator compartment cooler 4 and the freezer compartment main cooler 7. If this continues for a long time, for example 10 hours, this is determined by a timer and the first control valve 12 is closed, while the second control valve 15 is opened to stop the refrigerant supply to the refrigerator compartment cooler 4. As a result, the frost adhering to the refrigerator compartment cooler 4 is removed by natural melting.As a result, the refrigerant is continuously supplied to the refrigerator compartment cooler 4 for a long time, giving the frost a chance to melt naturally. To prevent 10- from causing a situation in which a large amount of frost adheres to a refrigerator compartment cooler 4 and reduces the cooling efficiency inside the refrigerator.

( I
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 cooling type temperature 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 an out-of-operation state for a long time with a high internal temperature due to a large load placed inside the refrigerator compartment 2.

(rV) Rapid refrigeration operation In this operation, the rapid refrigeration timer is manually started to drive the compressor 10, while the first control valve 12 is closed and the second control valve 15 is opened. 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.

10- Then, when the set time of the quick freezing timer has elapsed, the first control valve 12 opens and the second control valve 15 closes to forcefully perform a channel switching operation to shut down the refrigerator compartment cooler 4 and the freezer. The refrigerant is supplied to the room main cooler 7 and continues until a cooling stop command is given by the refrigerating room air temperature signal S2 to the refrigerating room temperature detecting element 34. In this way, temperature variations within the refrigerator compartment 2 during the rapid freezing operation period of the freezer compartment 3 are compensated.

(V) Defrosting operation Due to the forced circulation of cold air by the main cooler 7 for the freezer compartment, frost adheres to the main cooler 7 for the freezer compartment. Further, the frost adhering to the auxiliary cooler 5 sublimates and adheres to the main cooling unit 741 for the freezer compartment. 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 Based on the defrosting start command, the compressor motor 23 and fan motor 8 are driven and the first control valve 12 is forcibly opened to cool the refrigerator compartment cooler 4 and the freezer compartment. Refrigerant is supplied to the main cooler 7. This state continues until the first control valve 12 is closed by the refrigerator room air temperature signal S2 from the refrigerator room temperature detection element 34.
Forced cooling is performed. And refrigerator room air temperature signal S2
When the first control valve 12 is closed and the second control valve 15 is opened, the refrigerant is forcibly supplied to the auxiliary cooler 5 and the main cooler 7 for the freezer compartment, and this state is controlled by a dedicated timer. It continues for a certain period of time, for example, 15 minutes.

(B) Actual defrosting operation When the forced cooling operation before defrosting is completed, compressor 1
0 is stopped, the first control valve 12 and the second control valve 15 are closed, and the damper 28 is caused to close. Closing of this damper 28 or damper driving heater 2
This is done by applying current to the bellows portion 28a to expand the bellows portion 28a. In this way, water vapor filling the air passage chamber 6 during defrosting operation is prevented from being discharged into the freezing chamber 3 due to the convection effect due to the temperature difference in the freezing chamber 3 and freezing and depositing on the surface of the auxiliary cooler 5. To prevent. When the damper 28 is closed in this manner, the defrosting heater 21 is energized, and an actual defrosting operation for melting and removing the frost adhering to the main cooler 7 for the freezer compartment is started. Although the air around the main cooler 7 for the freezer compartment is warmed by the energization of the defrosting heater 21, the warm air does not enter the freezer compartment 3 because the damper 28 is in the closed state. When the defrosting is completed, the surface temperature of the main cooler 7 for the freezer compartment suddenly rises, and therefore the control unit 17 determines this based on the defrosting completion signal S4 obtained by the defrosting completion detection element 35 and defrosting. The power to the heater 21 is cut off, and operations associated with the completion of defrosting are performed.

(C) 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 defrosting heater 21 is powered off, a timer is used to pull the damper 28 for a predetermined short period of time, for example, 5 minutes, and then keep the damper 28 in the open state and the compressor 10 in the stopped state. During this period, the main cooler 7 for the freezer compartment
Water droplets adhering to the surface of the cooling device due to melting of frost are allowed to flow down naturally, thereby preventing these water droplets from freezing at the start of the cooling operation.

After the water droplet removal operation is completed by the timer, the forced storage temperature recovery operation is performed as follows.

That is, when the set time of the timer for removing water droplets has elapsed, the compressor 10 is forcibly driven and the second control valve 15 is opened to supply the refrigerant only to the auxiliary cooler 5 and the main cooler 7 for the freezer compartment. While the supplied defrosting residual heat absorption operation is forcibly performed for a predetermined period of time, for example, 10 minutes, during this period as well, the damper 28 is kept in a closed state following the water droplet removal operation, and the fan motor 8 is also kept in a stopped state. In this way, if the cooling operation is restarted and the damper 28 is opened to drive the fan motor 8 at the same time as the defrosting is completed, water vapor or To prevent the inconvenience that residual heat, that is, warm air is immediately blown out into the freezer compartment 3.

14- Next, after such a defrosting residual heat absorption operation, the damper 28 is opened again by the timer and the forced operation is performed to supply refrigerant only to the auxiliary cooler 5 and the main cooler 7 for the freezer compartment while driving the fan motor 8. After doing this for about 20 minutes, the freezer compartment 3
After this 20 minute period has elapsed, the subsequent control operation is shifted to normal operation based on the freezer compartment cooler section 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 is issued during the defrosting cycle (meaning that includes related operations before and after the actual box 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 performed with priority, the subsequent operations of the defrosting cycle are stopped, and the defrosting command wait state is resumed.

On the other hand, if the command for rapid freezing operation is received between the end of the defrost residual heat absorption operation and the end of the defrost residual heat absorption operation of the defrost cycle, the defrost operation will be given priority and will continue as is. let

In the above embodiment, in order to detect the refrigerator room temperature, the air temperature and the humidity 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〕

According to the present invention, since the auxiliary cooler is placed in the freezer compartment, by placing food on it, it is possible to quickly cool the food in the same manner as in the conventional direct cooling type. Food stored in the freezer compartment can be cooled more quickly than with conventional cold air circulation systems using the main cooler dedicated to the freezer compartment.

Further, according to the present invention, when defrosting the main cooler for the freezer compartment, the compressor is operated to forcibly cool the refrigerator compartment, which is not affected by the heat at all during defrosting, and then the freezing compartment. Therefore, the temperature rise in the refrigerator compartment can be suppressed as much as possible while the refrigeration cycle is stopped during defrosting, and the thermal effect on the freezer compartment during defrosting can be minimized by forcibly cooling the freezer compartment until immediately before defrosting operation. can be suppressed to Furthermore, since the main cooler for the freezer compartment is a cooler exclusively for the freezer compartment, there is less frost on the cooler, and the frequency and time of defrosting can be shortened. It is possible to eliminate the influence on the temperature rise in the room.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings relate to an embodiment of the present invention, in which Fig. 1 is a schematic longitudinal sectional side view of a refrigerator, Fig. 2 is a connection diagram of a refrigeration cycle, and Fig. 3 is a configuration explanation of a control circuit. 4 are wiring diagrams of the temperature detection unit, and FIGS. 5 and 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, 6 is an air passage chamber, 9 is a fan, 10 is a compressor, 12 is a first control valve, 15 is a second control valve,
18 is a temperature detection unit, 33 is a cooling type temperature detection element for the refrigerator compartment, 34 is a temperature detection element for the refrigerator compartment 17, and 36 is a frozen room temperature detection element. Applicant: Tokyo Shibaura Electric Co., Ltd. 18- No. 6 JP-A-Sho GO-29577 (8)

Claims (1)

[Claims] 1. A freezer compartment cooler consisting of an auxiliary cooler for placing food and cooling it, and a main cooler for cooling circulating air by a fan; a refrigerator compartment cooler; a compressor; a first control circuit that supplies both the main cooler for the freezer and the cooler for the refrigerator compartment; a second control circuit that supplies only the cooler for the freezer compartment; and a defrosting circuit that heats the main cooler. In a refrigerator equipped with a heater, when defrosting the main cooler, the compressor is forcibly operated for a predetermined time before energizing the heater, and under this operating state, the first control circuit is opened to supply the refrigerant to the refrigerator. A refrigerator characterized in that an operation is performed to supply refrigerant to a main cooler and a refrigerator compartment cooler, and then the second control circuit is opened to supply refrigerant to both the main and auxiliary coolers.