JP2011080731A - Refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent excessiveness or shortage in an amount of the recovered refrigerant from a freezing compartment cooler during pumping down in a refrigerator performing a refrigerating compartment cooling mode and a freezing compartment cooling mode. <P>SOLUTION: The refrigerator includes a switching valve 28 for switching between a refrigerating compartment cooling mode for supplying the refrigerant condensed by a condenser 26 by driving of a compressor 25 to a refrigerating compartment cooler 18, a freezing compartment cooling mode for supplying the condensed refrigerant to the freezing compartment cooler 20, and a full close mode for shutting off a refrigerant flow passage from the condenser 26 to the refrigerating compartment cooler 18 and the freezing compartment cooler 20; and a switching controller for executing a pumping down mode for driving the compressor 25 in the full close mode before executing the refrigerating compartment cooling mode. The compressor 25 is the capacity-variable compressor by variation of a rotational frequency, and executes the pumping down mode for the time in accordance with the rotational frequency of the compressor 25 in the pumping down mode. Therefore, it is possible to prevent excessiveness or shortage in the amount of the recovered refrigerant from the freezing compartment cooler 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a refrigerator provided with two coolers, that is, a refrigerator for a refrigerator compartment and a cooler for a freezer compartment, and particularly relates to a refrigerator that performs a pump-down operation.

  In recent years, for example, home refrigerators are provided with two coolers for a refrigerator compartment and a freezer compartment. In a refrigeration cycle incorporated in this type of refrigerator, a refrigerant flow path having a capillary tube and a refrigerator for a refrigerator compartment and a refrigerant flow path having another capillary tube and a refrigerator for a freezer compartment are connected in parallel, A switching valve for switching the refrigerant flow paths is provided.

  Then, by switching and controlling the switching valve, the cooling room cooling mode in which the refrigerant condensed in the condenser flows through the capillary tube to the cooling room cooler and returns to the compressor is separated from the refrigerant condensed in the condenser. The freezing chamber cooling mode in which the refrigerant flows through the capillary tube to the freezer cooler and returns to the compressor is alternately performed. Thereby, a refrigerator compartment and a freezer compartment are cooled alternately.

  By the way, in this type of refrigerator, in order to efficiently cool both the refrigerator compartment and the freezer compartment, it is possible to control the amount of refrigerant flowing through the refrigerator for the refrigerator compartment and the refrigerator for the freezer compartment to be appropriate. Necessary. In normal cases, the temperature of the freezer cooler is sufficiently lower than that of the refrigerator for the freezer compartment, so that the refrigerant tends to stay on the cooler side of the cooler freezer compartment. When switching to the room cooling mode, there is a circumstance that at the beginning of the switching, the amount of refrigerant flowing through the refrigerator for the refrigerator compartment is insufficient and tends to be short. In this case, the amount of refrigerant flowing through the refrigerator for the refrigerating chamber approaches an appropriate value with the passage of time thereafter. However, the shortage of the amount of refrigerant at the initial stage of the refrigerating chamber cooling mode causes a decrease in cooling efficiency.

Therefore, in this type of refrigerator, before the transition from the freezer cooling mode to the refrigerating room cooling mode, the pump down mode, that is, the refrigerant in both the freezer cooler and the freezer cooler with the switching valve fully closed. It is considered to execute a pump down mode in which the compressor is driven in a state where the flow path is shut off (see, for example, Patent Document 1). By executing this pump-down mode, the refrigerant staying in the freezer cooler can be recovered, and at the start of the next cold room cooling mode, a sufficient amount of refrigerant can flow through the cold room cooler. It becomes like this.
JP 2000-266444 A

  In Patent Literature 1, the pump-down operation is performed by determining the rotation speed and driving time of the compressor according to the temperature of the freezer cooler, or determining the rotation speed and driving time of the compressor according to the outside temperature. . For example, when the temperature of the freezer cooler is lower than the normal temperature, the rotation speed is lower than the rotation speed during pump down during normal operation and shorter than the pump down time during normal operation. On the contrary, when the temperature of the freezer cooler is higher than the normal temperature, the pump down operation is performed for a long time at a high rotational speed.

However, in general, when the rotational speed of the compressor is low, the refrigerant recovery amount from the freezer cooler per unit time is small, and conversely, when the rotational speed is high, the amount of refrigerant used for the freezer compartment is low. Although there is a circumstance that the amount of refrigerant recovered from the cooler is large, in the above-mentioned Patent Document 1, when the temperature of the cooler for the freezer compartment is lower than the normal temperature, the compressor is pumped at a low rotational speed for a short time. If the temperature of the freezer cooler is higher than the normal temperature, the pump down operation is performed for a long time at a high rotation speed. In some cases, the refrigerant cannot be collected, or the refrigerant is collected more than the amount necessary for cooling the refrigerator compartment, resulting in a wasteful pump-down operation.
In addition, if the pump down mode is performed by driving the compressor at a constant rotational speed for a certain period of time, the rotational speed of the compressor in the immediately preceding freezer cooling mode is the rotational speed of the compressor in the pump down mode. And can be very different. Then, a large load is suddenly applied to the compressor, and the operation efficiency is deteriorated.

  In this regard, in a variable capacity type compressor, the number of rotations is usually set to a value according to the temperature of the freezer compartment or the refrigerator compartment in the freezer compartment cooling mode or the refrigerator compartment cooling mode. Since the rotation speed of the compressor in the pump down mode is determined in accordance with, for example, the temperature of the freezer cooler or the outside air temperature, the rotation speed of the compressor in the pump down mode is the same as that in the immediately preceding freezer cooling mode. In some cases, the rotational speed of the compressor may differ greatly, and the problem that the compressor is heavily loaded at the start of the pump-down mode remains unsolved.

  The present invention has been made in view of the above circumstances, and its purpose is that it is necessary for the next cooling mode in the pump-down mode without making the rotational speed of the compressor significantly different from the rotational speed in the immediately preceding cooling mode. It is in providing the refrigerator which can collect | recover the quantity of refrigerant | coolants as much as possible without excess and deficiency.

  The refrigerator of the present invention includes a refrigerator for a refrigerator compartment for cooling the refrigerator compartment, a refrigerator for the refrigerator compartment for cooling the refrigerator compartment, and the refrigerant condensed by the condenser driven by the compressor. A refrigerating room cooling mode for supplying to the refrigerating machine, a refrigerating room cooling mode for supplying at least the refrigerant condensed by the condenser to the refrigerating room cooler, the refrigerating room cooler and the freezing from the condenser A refrigerant channel switching means for switching between a fully closed mode in which the refrigerant flow path to the room cooler is cut off and the refrigerant supply to the refrigerator room cooler and the refrigerant chamber cooler is cut off, and the refrigerator room cooling A switching control means for executing a pump down mode for driving the compressor in the fully closed mode prior to executing at least one of the mode and the freezer cooling mode. The compressor is of a variable capacity type by changing the rotation speed, and the switching control means sets the rotation speed of the compressor in the pump down mode to be around the rotation speed in the cooling mode performed immediately before, and The pump down mode is executed by setting the execution time of the pump down mode to a time corresponding to the rotation speed of the compressor so that the execution time is shorter as the rotation speed of the compressor is higher. Is.

  According to the present invention, since the rotation speed of the compressor in the pump down mode is determined in the vicinity of the rotation speed in the immediately preceding cooling mode, there is no possibility that a large load is applied to the compressor when switching to the pump down mode. In addition, the pump-down mode is executed for a long time when the rotation speed of the compressor is low, and the execution time is shortened when the rotation speed is high. Therefore, the refrigerant recovery amount from the cooler is excessively and insufficiently caused. Can not be.

Refrigeration cycle configuration diagram showing the first embodiment of the present invention Schematic vertical side view of refrigerator Electrical configuration block diagram Mode control flowchart Graph showing the relationship between compressor frequency and pump down mode execution time Flowchart of mode control showing the second embodiment of the present invention Flowchart of mode control showing the third embodiment of the present invention Flowchart of mode control showing the fourth embodiment of the present invention Circuit diagram of temperature sensor Refrigeration cycle configuration diagram showing a fifth embodiment of the present invention

Hereinafter, the present invention will be specifically described with reference to embodiments. In the following embodiments, the pump down mode is performed only when the refrigerator compartment cooling mode is executed.
(First embodiment)
1 to 5 show a first embodiment of the present invention. FIG. 2 shows a schematic configuration of the refrigerator. As shown in FIG. 2, the refrigerator body 1 divides the inside of the heat insulating box 2 into upper and lower portions by heat insulating partition walls 2 a, 2 b, 2 c, so that the refrigerator room 3, the ice making room 4, the vegetable room 5, A freezer compartment 6 is provided. Although not shown, the ice making chamber 4 is provided side by side with the small freezer compartment.

  The hinged door 7 is provided at the front of the refrigerator compartment 3, and the drawer-type doors 8, 9, 10 are provided at the front of the ice making chamber 4, the vegetable compartment 5, and the freezer compartment 6, respectively. It has been. An ice storage container 11 is connected to the back surface of the door 8, and storage containers 12 and 13 are connected to the back surfaces of the doors 9 and 10, respectively. A refrigerating room temperature sensor (room temperature sensor) 14 for detecting the temperature in the refrigerating room 3 is provided in the refrigerating room 3, and the temperature in the freezing room 6 is provided in the freezing room 6. A freezer temperature sensor (room temperature sensor) 15 is provided for detecting the above.

  On the back wall portion of the vegetable compartment 5, a refrigerator compartment 16 for refrigeration compartment and a cooler compartment 17 for freezer compartment are provided so as to overlap each other. In the refrigerator compartment 16 for the refrigerator compartment, a refrigerator 18 for refrigerator compartment and a blower fan 19 for cooling are provided for cooling the refrigerator compartment 3 and the vegetable compartment 5. In the freezer compartment cooler chamber 17, a freezer compartment cooler 20 and a freezing blower fan 21 for cooling the freezer compartment 6 and the ice making chamber 4 are provided. Although not shown in detail, the cooler 18 for the refrigerating chamber and the blower fan 19 for refrigerating, the cooler 20 for the refrigerating chamber and the blower fan 21 for freezing are provided at positions shifted left and right. The freezer cooler 20 is provided with a defrosting heater (not shown).

  Thus, when the refrigeration fan 19 is driven, the cold air generated by the refrigeration room cooler 18 passes from the upper part of the refrigeration room cooler room 16 through the air duct 22 and from the plurality of outlets to the refrigeration room. 3 is supplied to the inside of the vegetable compartment 5 and then returned to the lower part of the refrigerator compartment 16 for the refrigerator compartment. Thus, the inside of the refrigerator compartment 3 and the vegetable compartment 5 is cooled to a refrigerator temperature zone of, for example, 2 ° C to 5 ° C.

  Further, when the refrigeration blower fan 21 is driven, the cold air generated by the freezer cooler 20 passes from the upper part of the freezer cooler chamber 17 through a duct (not shown) or the like to the ice making chamber 4 or the freezer compartment. 6 and the small freezer compartment are circulated to be returned to the lower part of the freezer cooler compartment 17. Thus, the ice making room 4, the freezing room 6 and the small freezing room are cooled to a freezing temperature zone of, for example, −18 ° C. to −21 ° C. Note that the small freezer compartment provided side by side with the ice making chamber 4 may be a refrigerating temperature zone or a switching chamber cooled to a freezing temperature zone according to a set specification.

  In the refrigerator main body 1 as described above, the refrigeration cycle 23 shown in FIG. 1 is incorporated. At this time, a machine room 24 is provided on the lower back side of the refrigerator body 1, a compressor 25 and a condenser 26 (shown only in FIG. 1), and a cooling fan for cooling them in the machine room 24. 27 (see FIGS. 1 and 3) and the like are arranged. The compressor 25 is of a variable capacity type and is driven at a variable speed by inverter control, for example. The number of rotations of the compressor 25 is set to a value according to the difference between the temperature detected by the refrigerator temperature sensor 14 and the target cooling temperature (for example, 2 ° C.) when the refrigerator compartment 3 is cooled. The value is determined according to the difference between the temperature detected by the freezer temperature sensor 15 and the cooling target temperature (for example, -21 ° C.). That is, the rotational speed of the compressor 25 is determined to a value corresponding to the magnitude of the thermal load of the refrigerator compartment 3 or the freezer compartment 6.

  As shown in FIG. 1, the refrigeration cycle 23 includes a three-way valve having the compressor 25, the condenser (condenser) 26, one inlet 28a, a first outlet 28b, and a second outlet 28c. The switching valve 28, the first capillary tube (first decompression means) 29 connected to the first outlet 28b of the switching valve 28, the freezer cooler 20, and the check valve 30 are sequentially closed by a refrigerant pipe. In addition to being connected, a second capillary tube (second decompression means) 31 and the refrigerating room cooler 18 are connected between the second outlet 28 c of the switching valve 28 and the check valve 30. Has been.

  Thus, when the switching valve 28 is switched to the first outlet 28b open (second outlet 28c closed) (freezer compartment cooling mode), the refrigerant is condensed in the condenser 26 by driving the compressor 25. After that, the refrigerant is supplied to the freezer cooler 20 through the first capillary tube 29 and then returned to the compressor 25 through the check valve 30 in order. On the other hand, when the switching valve 28 is switched to the second outlet 28c open (first outlet 28b closed) (refrigeration chamber cooling mode), the refrigerant is condensed in the condenser 26 by driving the compressor 25. After that, the refrigerant is supplied to the refrigerator 18 through the second capillary tube 31 and then returned to the compressor 25 through the check valve 30.

  Further, the switching valve 28 can close both the first outlet 28b and the second outlet 28c to block the refrigerant flow path from the condenser 26 to the refrigerator 18 for the refrigerator compartment and the refrigerator 20 for the freezer compartment. (Fully closed mode). An operation state in which the compressor 25 is driven in the fully closed mode of the switching valve 28 is referred to as a pump down mode. The switching valve 28 constitutes a refrigerant flow path switching unit, and is switched and controlled by a control device 32 that functions as a switching control unit.

  Now, as shown in FIG. 3, the refrigerator main body 1 is provided with a control device 32 mainly composed of a microcomputer. Signals from the refrigerator temperature sensor 14 and the freezer temperature sensor 15 are input to the control device 32. Then, the control device 32 controls the compressor 25, the switching valve 28, the refrigeration blower fan 19, the refrigeration blower fan 21, the cooling fan 27, and the like based on the input signals in accordance with an operation control program stored in advance. It is supposed to be. Here, the refrigeration blower fan 19 is turned on when the refrigerant is flowing through the refrigeration room cooler 18. The refrigeration blower fan 21 is turned on when the refrigerant is flowing through the freezer cooler 20. The cooling fan 27 is turned on when the compressor 25 is turned on.

  As will be described later in the description of the operation, the control device 32 switches the switching valve 28 in accordance with the software, thereby allowing the refrigerant to flow through the refrigerator 18 for the refrigerator compartment to cool the refrigerator compartment 3 and the vegetable compartment 5. The cooling operation is executed while alternately switching between the cooling mode and the freezing chamber cooling mode in which the refrigerant flows through the freezer cooler 20 to cool the freezing chamber 6 and the ice making chamber 4 (control operation). Thus, while the refrigerator compartment 3 (and the vegetable compartment 5) and the freezer compartment 6 (and the ice making chamber 4) are alternately cooled, the temperatures in all the chambers 3 to 6 are maintained near the set temperature. .

  In this case, the ON temperature and the OFF temperature are set for each of the refrigerator compartment 3 and the freezer compartment 6, and the control device 32 determines that the detected temperature of the refrigerator compartment temperature sensor 14 is the ON temperature set for the refrigerator compartment 3 and When the temperature reaches the OFF temperature, the refrigerator compartment cooling mode is started and ended, and when the temperature detected by the freezer temperature sensor 15 reaches the ON temperature and the OFF temperature set for the freezer compartment 6, the freezer cooling mode is started. And it is the structure which switches the switching valve 28 so that it may complete | finish.

  Specific examples of the ON temperature and the OFF temperature are as follows. For the refrigerator compartment 3, the ON temperature is set to 5 ° C. and the OFF temperature is set to 2 ° C. For the freezer compartment 6, the ON temperature is −18 ° C. and the OFF temperature is − It is set to 21 ° C. In the refrigerator compartment cooling mode and the freezer compartment cooling mode, after performing a minimum cooling time (for example, 20 minutes in the refrigerator compartment cooling mode and 30 minutes in the freezer compartment cooling mode), (1) the detected temperature of the room being cooled (2) When the maximum cooling time (for example, 40 minutes in the refrigerator compartment cooling mode, 60 minutes in the freezer compartment cooling mode) or more has elapsed since the mode switching, (3) Not subject to cooling When the detected temperature of the chamber becomes equal to or higher than the ON temperature, the process is terminated in any case. The compressor 25 is normally driven at all times, but is turned off when the temperatures of both the chambers 3 and 6 are both lower than the OFF temperature and the PID calculation is lower than a certain value.

  Moreover, in this embodiment, when performing the refrigerator compartment cooling mode after execution of freezer compartment cooling mode, the control apparatus 32 performs pump down mode beforehand, and makes it transfer to refrigerator compartment cooling mode after that. Yes. By executing this pump-down mode, it is possible to eliminate the shortage of refrigerant with respect to the refrigerator 18 for the refrigerator compartment when shifting to the refrigerator compartment cooling mode.

  In this embodiment, the control device 32 stores the final rotation frequency (the number of rotations per second) of the compressor 25 in the freezer cooling mode in a memory (storage means) (not shown) and executes the pump down mode. In doing so, the rotational frequency of the compressor 25 in the immediately preceding freezer compartment cooling mode is retrieved from the memory, and the rotational frequency of the compressor 25 in the pump-down mode is determined as the final rotational frequency in the freezer compartment cooling mode executed immediately before. In the vicinity, in this embodiment, the rotation frequency is set to the same rotation frequency as the final rotation frequency in the freezer compartment cooling mode executed immediately before.

  Further, the execution time of the pump down mode is set to a time corresponding to the rotation frequency so as to be shorter as the rotation frequency of the compressor 25 in the pump down mode is higher. Specifically, as shown in FIG. 5, the rotation frequency is set to a time multiplied by a coefficient (<1) so as to be inversely proportional to the rotation frequency of the compressor 25. However, when the rotation frequency is equal to or lower than a predetermined low frequency (for example, 22 Hz), the execution time of the pump-down mode is set to a fixed long time (for example, 120 seconds) regardless of the rotation frequency. When the rotation frequency of the compressor 25 is equal to or higher than a predetermined high frequency (for example, 66 Hz), the execution time of the pump down mode is set to a fixed short time (for example, 45 seconds) regardless of the rotation frequency.

  Next, the operation of the above configuration will be described with reference to the flowchart of FIG. FIG. 4 shows a processing procedure related to mode switching executed by the control device 32. That is, when the temperatures detected in the refrigerator compartment 3 and the freezer compartment 6 by the refrigerator compartment temperature sensor 14 and the freezer compartment temperature sensor 15 are both lower than the ON temperature, the compressor 25 is stopped (cooling is stopped in step S1). NO ”,“ NO ”in step S8 and step S9).

  For example, when the detected temperature of the freezer compartment 6 becomes equal to or higher than the ON temperature (“YES” in step S1), the compressor 25 is started and the switching valve 28 is switched to open the first outlet 28b to cool the freezer compartment. The mode is executed (step S2). By executing this freezer cooling mode, the refrigerant compressed by the compressor 25 and condensed by the condenser 26 is supplied to the freezer cooler 20. Then, the air in the freezer compartment cooler chamber 17 is cooled by the freezer compartment cooler 20, and the cold air is supplied to the ice making chamber 4 and the freezer compartment 6 by the freezing blower fan 21. The freezer compartment 6 is cooled. During execution of this freezer compartment cooling mode, the compressor 25 is controlled to a rotation frequency according to the difference between the detected temperature of the freezer compartment 6 and a target temperature, for example, an OFF temperature (-21 ° C.).

  In the freezer compartment cooling mode, after the minimum cooling time has elapsed ("YES" in step S3), when the elapsed time from the start of the mode is equal to or longer than the longest cooling time ("YES" in step S4), or in the refrigerator compartment 3 The process ends when the detected temperature is equal to or higher than the ON temperature (“YES” in step S5) or when the detected temperature of the freezer compartment 6 is equal to or lower than the OFF temperature (“YES” in step S6).

  When the longest cooling time has elapsed, or when the freezer cooling mode is terminated because the detected temperature of the refrigerating chamber 3 has reached the ON temperature or higher, the operation proceeds to the refrigerating chamber cooling mode (step S17). When the detection temperature of the freezer compartment 6 is less than the OFF temperature when the detected temperature of the freezer compartment 6 is lower than the OFF temperature, and the detected temperature of the refrigerator compartment 3 is lower than the OFF temperature ("NO" in step S7), the refrigerator is cooled. When the mode is shifted to the mode (step S17) and the temperature is equal to or lower than the OFF temperature (“YES” in step S7), the cooling is stopped and the compressor 25 is stopped (step 8). Then, after the cooling is stopped, when the detected temperature of the refrigerator compartment 3 becomes equal to or higher than the ON temperature of the refrigerator compartment 3 (“YES” in step S9), the operation proceeds to the refrigerator compartment cooling mode (step S17).

As described above, when the refrigerator compartment cooling mode is switched to the refrigerator compartment cooling mode (step S17), the refrigerant stored in the refrigerator compartment cooler 20 is collected prior to the execution of the refrigerator compartment cooling mode. A pump down mode is performed (step S15).
That is, when executing the pump down mode, first, the rotation frequency of the compressor 25 and the execution time of the pump down mode in the pump down mode are set. In the present embodiment, the rotation frequency of the compressor in the pump down mode is set to the same rotation frequency as the rotation frequency at the end of the immediately preceding freezer compartment cooling mode (rotation speed setting means). Accordingly, in a normal case, the compressor 25 enters the pump down mode while maintaining the rotation speed in the freezer compartment cooling mode. The execution time of the pump down mode is set to a time obtained by multiplying the rotation frequency of the compressor 25 by a coefficient (“NO” in step S10, “NO” in step S12, step S14; execution time setting means). .

  However, when the rotational frequency of the compressor 25 is equal to or lower than a predetermined low frequency, the execution time of the pump down mode is set to a constant long time regardless of the rotational frequency of the compressor 25 (step S10). "YES", step S11; execution time correction means). When the rotation frequency of the compressor 25 exceeds a predetermined high frequency, the execution time of the pump down mode is set to a constant short time regardless of the rotation frequency of the compressor 25 (step S10). "NO", "YES" in step S12, step S13; execution time correction means).

  When the rotational frequency of the compressor 25 in the pump down mode and the execution time of the pump down mode are determined as described above, the switching valve 28 is set to the fully closed mode in which both the first outlet 28b and the second outlet 28c are closed. In this fully closed mode, the pump down mode in which the compressor 25 is driven is executed. By executing this pump-down mode, the refrigerant stored in the freezer cooler 20 is sucked into the compressor 25 and sent to the condenser 26.

  When the execution time of the pump-down mode has elapsed (“YES” in step S16), the pump-down mode ends. Then, the switching valve 28 is switched to open the second outlet 28c, and the refrigerator compartment cooling mode is executed (step S19). By executing the refrigerating room cooling mode, the refrigerant compressed by the compressor 25 and condensed by the condenser 26 is supplied to the refrigerating room cooler 18. Then, the air in the refrigerator room cooler room 16 is cooled by the refrigerator room cooler 18, and the cold air is supplied to the refrigerator room 3 and the vegetable room 5 by the refrigerator fan 19, whereby the refrigerator room 3 and the vegetable room. Chamber 5 is cooled. During the execution of the refrigerator compartment cooling mode described above, the compressor 25 is controlled to a rotation frequency according to the difference between the detected temperature of the refrigerator compartment 3 and a target temperature, for example, the OFF temperature (2 ° C.).

  In the refrigerator compartment cooling mode, after the minimum cooling time has elapsed (“YES” in step S18), when the elapsed time from the start of the mode becomes equal to or longer than the longest cooling time (“YES” in step S19), or the freezer compartment 6 The process ends when the detected temperature is equal to or higher than the ON temperature ("YES" in step S20) or when the detected temperature of the refrigerator compartment 3 is equal to or lower than the OFF temperature ("YES" in step S21).

  When the longest cooling time has elapsed, or when the refrigerator compartment cooling mode is ended because the detected temperature of the freezer compartment 6 has become equal to or higher than the ON temperature, the operation proceeds to the freezer compartment cooling mode (step S2). When the detected temperature of the freezer compartment 6 is lower than the OFF temperature when the detected temperature of the freezer compartment 3 is lower than the OFF temperature when the detected temperature of the freezer compartment 3 is lower than the OFF temperature ("NO" in step S22), the freezer compartment is cooled. When the mode is shifted to the mode (step S2) and the temperature is equal to or lower than the OFF temperature (“YES” in step S22), the cooling is stopped and the compressor 25 is stopped (step 8).

  As described above, except for the case where the refrigerator compartment 3 and the freezer compartment 6 are both below the OFF temperature, the freezer compartment cooling mode and the refrigerator compartment cooling mode in which the pump down mode is executed in advance are alternately repeated. The refrigeration room 3 and the freezing room 6 are controlled to the refrigeration temperature zone and the freezing temperature zone, respectively.

Thus, according to this embodiment, since the pump down mode is executed prior to executing the refrigerator compartment cooling mode, sufficient refrigerant necessary for cooling the refrigerator compartment 3 is recovered from the refrigerator for freezer compartment 20. Later, it is possible to shift to the refrigerating room cooling mode, and it is possible to solve the problem that the refrigerant becomes insufficient when switched to the refrigerating room cooling mode.
Further, since the rotational frequency of the compressor 25 in the pump down mode is set to the final rotational frequency in the immediately preceding freezer compartment cooling mode, the rotational speed fluctuation of the compressor 25 when the freezer compartment cooling mode is shifted to the pump down mode is caused. In addition, an overload state due to a sudden increase in the frequency of the compressor 25 can be prevented.

  Furthermore, the execution time of the pump down mode is basically set to a time inversely proportional to the rotational frequency of the compressor 25. Therefore, if the rotational frequency of the compressor 25 is high, the amount of refrigerant recovered per unit time is large. Conversely, if the rotational frequency of the compressor 25 is low, the refrigerant necessary for the refrigerator compartment cooling mode can be recovered as much as possible under the circumstances that the amount of refrigerant recovered per unit time decreases.

  In this case, if the rotational frequency of the compressor 25 becomes higher than a predetermined high frequency, the execution time of the pump-down mode becomes too short and the refrigerant recovery amount becomes insufficient. Therefore, the rotational frequency of the compressor 25 is predetermined. When the frequency is higher than the high frequency, a fixed short time is set regardless of the rotation frequency. Conversely, when the rotation frequency of the compressor 25 is lower than a predetermined low frequency, the execution time of the pump down mode becomes too long, and the refrigerant is recovered. In this embodiment, when the rotational frequency of the compressor 25 is higher than a predetermined high frequency or lower than a predetermined low frequency, the execution time of the pump down mode is set. Regardless of the rotation frequency, the fixed amount of time is set to a short time or a long time, so that it is possible to more reliably prevent the refrigerant amount to be recovered from being excessive or insufficient.

(Second Embodiment)
FIG. 6 shows a second embodiment of the present invention. The second embodiment is different from the first embodiment in that the temperature of the refrigerator compartment 3 is taken into account in order to determine the execution time of the pump down mode. In other words, when the temperature of the refrigerator compartment 3 is high, it is necessary to supply more refrigerant to the refrigerator 18 for the refrigerator compartment. Therefore, in the present embodiment, when the pump down mode is started, when the detected temperature of the refrigerator compartment 3 is a predetermined temperature or higher, for example, 7 ° C. or higher, the pump down mode set in step S11 or step S13 or step S14. Further, a certain time, for example, 30 seconds is added to the execution time of (2) to obtain the execution time of the pump down mode (“YES” in step A1, step A2; execution time correction means)

  Thus, when the temperature of the refrigerator compartment 3 is high, the execution time of the pump down mode is increased by 30 seconds, so even if there is a situation where the temperature of the refrigerator compartment 3 is high and a lot of refrigerant is required for the cooling. Then, it is possible to shift to the refrigerating room cooling mode with the necessary amount of refrigerant recovered.

(Third embodiment)
FIG. 7 shows a third embodiment of the present invention. This third embodiment differs from the second embodiment described above in that not only the temperature of the refrigerator compartment 3 but also the outside air temperature is taken into account in order to determine the execution time of the pump down mode. That is, the refrigerating room temperature sensor 14 is disposed in the back of the refrigerating room 3 and it is relatively difficult for outside air to enter the refrigerating room 3 when the door 7 is opened. For this reason, when the outside air temperature is high, if the outside air temperature is low, the temperature rise at the location of the refrigerator compartment temperature sensor 14 due to the influence of the outside air is relatively small, and the refrigerator compartment cooling mode is started. The OFF temperature is detected within a relatively short time, and the refrigerator compartment cooling mode is terminated. However, the temperature has not yet decreased to the OFF temperature in the refrigerating chamber 3, particularly in a wide range where outside air easily enters near the front opening.

  Therefore, in the present embodiment, a temperature sensor for detecting the outside air temperature, that is, an outside air temperature sensor (not shown) is provided in the refrigerator main body 1, and the outside air temperature is a predetermined temperature or lower, for example, 11 ° C. or lower at the end of the freezer cooling mode. In this case, a time obtained by adding a certain time, for example, 30 seconds, to the execution time of the pump down mode set in step S11, step S13 or step S14 and further step A2 is set as the execution time of the pump down mode (step "NO" at A3, step A4; execution time correction means)). As a precaution, in the case of the present embodiment, when the detected temperature of the refrigerator compartment 3 is 7 ° C. or less and the outside air temperature is 11 ° C. or less, the execution time of the pump down mode is set longer by 1 minute in total. .

  Thus, according to the present embodiment, when the outside air temperature is low, the execution time of the pump down mode is increased by 30 seconds, so that it is possible to shift to the refrigerating room cooling mode with more refrigerant recovered. For this reason, a large amount of refrigerant is supplied to the cooler 18 for the refrigerator compartment at the start of the refrigerator compartment cooling mode to increase the cooling capacity. Thereby, when the refrigerator compartment cooling mode is started, the refrigerator compartment temperature sensor 14 detects the OFF temperature within a relatively short time, and even if the refrigerator compartment cooling mode is finished, the refrigerator compartment 3 is sufficiently cooled. can do.

(Fourth embodiment)
8 and 9 show a fourth embodiment of the present invention. The fourth embodiment differs from the third embodiment described above in that when the refrigerator temperature sensor 14 or an outside air temperature sensor (not shown) fails, a predetermined time (30 seconds) is not added to the pump down execution time. It is what I did. That is, the refrigerating room temperature sensor 14 is composed of a temperature sensitive element having a positive temperature characteristic such as a thermistor, and is connected in series with the resistor 33 between the power source (+ Acc) and the ground as shown in FIG. The circuit is configured. And the voltage of the connection point of the refrigerator compartment temperature sensor 14 and the resistance 33 is input into the control apparatus 32 as detection temperature of the refrigerator compartment temperature sensor 14, and the controller 32 detects the temperature of the refrigerator compartment 3 from the input voltage. . The same applies to the freezer temperature sensor 15 and the outside temperature sensor (not shown).

  The cause of failure of the refrigerator temperature sensor 14 and the outside air temperature sensor is disconnection or short circuit. In the case of a disconnection, the control device 32 receives a power supply (+ Acc) voltage or a ground voltage that is significantly different from the normal temperature detection voltage. Similarly, in the case of a short circuit, a power supply (+ Acc) voltage or a ground voltage is input to the control device 32. Therefore, when the power supply (+ Acc) voltage or the ground voltage is input from the refrigerating room temperature sensor 14 or the outside air temperature sensor (not shown), the control device 32 determines that these temperature sensors are faulty (Step B1, Step B2, Sensor failure determination means). When it is determined that the cold room temperature sensor 14 is malfunctioning, 30 seconds is not added to the execution time of the pump down mode regardless of the value detected by the cold room temperature sensor 14 (“YES” in step B1). ”And bypasses steps A1 and A2), and when it is determined that the outside air temperature sensor has failed, 30 seconds is not added to the execution time of the pump down mode regardless of the detected temperature of the outside air temperature sensor ( In step B2, “YES” is set, and steps A3 and A4 are bypassed).

  Thereby, although the refrigerator compartment temperature sensor 14 and the outside air temperature sensor are out of order, the refrigerator compartment 3 is less than 7 ° C. or the outside air temperature exceeds 11 ° C., but the pump down mode is extra. It is possible to prevent the unnecessary pump down mode from being performed by preventing the system from being executed for a long time.

(Fifth embodiment)
FIG. 10 shows a fifth embodiment of the present invention. This embodiment differs from the first to fourth embodiments in that the outlet of the freezer cooler 20 is connected to the inlet of the refrigerator freezer 18.
By comprising in this way, the refrigerator compartment 3 can be cooled also in freezer compartment cooling mode.

(Other embodiments)
The present invention is not limited to the above embodiment, and may be modified or expanded as follows.
Even if the rotational frequency of the compressor 25 in the pump down mode is not necessarily the same as the rotational frequency at the end of the immediately preceding freezer compartment cooling mode, the compressor 25 is suddenly subjected to a large load. Any frequency within a range where the change in rotational frequency does not act is sufficient.
The pump down mode is performed prior to the execution of the refrigerating room cooling mode when switching from the freezer cooling mode to the refrigerating room cooling mode, and also when the freezer room is switched from the refrigerating room cooling mode to the freezer cooling mode. It may be performed prior to the execution of the cooling mode. Thereby, also when cooling the freezer compartment 6, the refrigerant | coolant amount required for cooling of the freezer compartment 6 can be collect | recovered from the refrigerator 18 for refrigerator compartments.
The pump down mode may be performed only in one of the switching from the refrigerator compartment cooling mode to the freezer compartment cooling mode and the switching from the freezer compartment cooling mode to the refrigerator compartment cooling mode.

  In the drawings, 1 is a refrigerator room, 4 is an ice making room, 5 is a vegetable room, 6 is a freezer room, 14 is a refrigerator temperature sensor (temperature sensor), 15 is a freezer temperature sensor (temperature sensor), and 18 is refrigerator. The room cooler, 20 is a freezer cooler, 25 is a compressor, 26 is a condenser, 28 is a switching valve (refrigerant flow path switching means), and 32 is a control device (switching control means, determination means).

Claims (4)

A refrigerator for the refrigerator compartment for cooling the refrigerator compartment;
A freezer cooler for cooling the freezer;
A refrigerating room cooling mode for supplying the refrigerant condensed by the condenser by driving the compressor to the refrigerating room cooler, and a freezing room cooling for supplying the refrigerant condensed by the condenser to at least the refrigerating room cooler. Mode, and fully closed to cut off the refrigerant flow from the condenser to the refrigeration room cooler and the freezer compartment cooler to cut off the refrigerant supply to the refrigeration room cooler and the freezer room cooler. Refrigerant channel switching means for switching between modes,
A switching control means for executing a pump down mode for driving the compressor in the fully closed mode prior to executing at least one of the refrigerator compartment cooling mode and the freezer compartment cooling mode. In
The compressor is a variable capacity type by changing the rotational speed,
The switching control means sets the rotation speed of the compressor in the pump down mode around the rotation speed in the cooling mode performed immediately before, and sets the execution time of the pump down mode to the rotation speed of the compressor. The refrigerator is characterized in that the pump-down mode is executed at a time corresponding to the rotation speed of the compressor so that the shorter the time is, the shorter the time is. A temperature sensor that detects the temperature of the refrigerating room or the freezing room that is cooled by a cooling mode that performs the pump-down mode in advance among the refrigerating room cooling mode and the freezing room cooling mode;
2. The switching control means, wherein when the temperature sensor detects a predetermined temperature or more, the execution time of the pump down mode is set longer than the time according to the rotation speed of the compressor. Refrigerator. It has a temperature sensor that detects the outside temperature,
The switching control means is characterized in that when the temperature sensor for detecting the outside air temperature detects a predetermined temperature or lower, the execution time of the pump down mode is set longer than the time according to the rotation speed of the compressor. The refrigerator according to claim 1 or 2. A determination means for determining a failure of the temperature sensor;
When the determination unit determines that the temperature sensor has failed, the switching control unit sets the execution time of the pump down mode from the time corresponding to the rotation speed of the compressor regardless of the temperature detected by the temperature sensor. 4. The refrigerator according to claim 2, wherein the time is determined according to the number of rotations of the compressor without increasing the time.

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