JP6120367B2 - refrigerator - Google Patents

Description

  The present invention relates to a refrigerator having a rapid cooling mode for rapidly cooling a storage room.

  A conventional refrigerator is disclosed in Patent Document 1. This refrigerator includes a refrigerator compartment and a freezer compartment, and an evaporator is connected to a compressor that operates a refrigeration cycle. Cold air generated by heat exchange with the evaporator is sent to the refrigerator compartment and the freezer compartment by driving the blower fan, and the refrigerator compartment and the freezer compartment are cooled.

  At this time, if the temperature of the evaporator and the temperature of the freezer compartment exceed a predetermined temperature, it is determined that the heat load of the evaporator is large, and the blower fan is stopped or decelerated. When the heat load on the evaporator is reduced, the blower fan is driven at the original rotational speed to send out cool air. Thereby, deterioration of cooling efficiency can be prevented and power saving of the refrigerator can be achieved.

JP 2006-214614 A (Pages 9 to 11, FIG. 4)

  However, according to the conventional refrigerator, when the storage room for pull-down operation or the like immediately after turning on the power is in a high temperature state and rapid cooling is required, if the temperature of the evaporator rises due to the high temperature of the storage room, the blower fan Stop or slow down. Thereby, since the cooling of the storage room does not proceed quickly, there is a problem that the convenience of the refrigerator is poor.

  An object of this invention is to provide the refrigerator which can cool rapidly at the time of a pull-down driving | operation etc. and can improve the convenience.

  To achieve the above object, the present invention provides a compressor that operates a refrigeration cycle, an evaporator that is connected to the compressor and cools a first storage chamber, and a heat load of the evaporator includes a plurality of heat load stages. A thermal load variable section that is variable to the compressor and an overload detection section that detects an overload of the compressor, and the thermal load variable when the non-overload state of the compressor continues for a predetermined non-overload time. A non-overload transition operation in which the thermal load of the evaporator is shifted to a higher thermal load stage by the unit, and the thermal load variable unit further reduces the thermal load of the evaporator when the overload of the compressor is detected. A quenching mode having an overload transition operation for shifting to a low heat load stage is provided.

  Further, the present invention is characterized in that, in the refrigerator configured as described above, the heat load of the evaporator is varied so that the ambient temperature of the evaporator is lower than a predetermined temperature in the predetermined heat load stage.

  In the refrigerator configured as described above, the non-overload transition operation is performed when the ambient temperature of the evaporator continues for a low temperature time shorter than the non-overload time and becomes lower than a predetermined temperature. It is characterized by that.

  Further, the present invention is characterized in that in the refrigerator having the above-described configuration, a fan that sends out the cold air heat-exchanged with the evaporator to the first storage chamber is provided, and the thermal load variable unit varies the driving state of the fan. .

  According to the present invention, in the refrigerator configured as described above, a second storage chamber that is cooled by the evaporator and maintained at a higher temperature than the first storage chamber, and a cold air passage between the evaporator and the second storage chamber are provided. A damper that opens and closes, and the thermal load variable section varies the open / close state of the damper.

  In the refrigerator configured as described above, the overload detection unit may detect the driving current of the compressor, the shell temperature of the compressor, or the pressure on the refrigerant inflow side of the compressor, and detect the overload. When the detected value of the section becomes larger than a predetermined value, it is determined that the compressor is overloaded.

  According to the present invention, in the refrigerator configured as described above, a cooling capacity stage is provided in which the cooling speed of the evaporator is varied by setting a set number of rotations of the compressor in a plurality of stages, and the non-overload transition operation is performed in the cooling mode. It includes an operation for shifting the capacity stage to a higher cooling capacity stage, and the overload transition operation includes an operation for shifting the cooling capacity stage to a lower cooling capacity stage.

  According to the present invention, the overload detection unit that detects the overload of the compressor and the thermal load variable unit that varies the thermal load of the evaporator are provided. When the compressor is in an overload state, a non-overload transition operation that shifts the heat load of the evaporator to a higher heat load stage when the non-overload state of the compressor continues for a predetermined time in the rapid cooling mode, and An overload transfer operation is performed to shift the heat load of the evaporator to a lower heat load stage. Thereby, even if the temperature of an evaporator is high temperature, a storage chamber can be cooled rapidly. Further, when the compressor is overloaded, the thermal load of the evaporator can be reduced by the overload transition operation, and the compressor can be protected. Therefore, the convenience of the refrigerator can be improved.

Side surface sectional drawing which shows the refrigerator of embodiment of this invention The block diagram which shows the structure of the refrigerator of embodiment of this invention. The flowchart which shows the operation | movement at the time of power activation of the refrigerator of embodiment of this invention. The flowchart which shows operation | movement of the rapid cooling mode of the refrigerator of embodiment of this invention. The flowchart which shows the operation | movement of the stage discrimination | determination process of the refrigerator of embodiment of this invention. The flowchart which shows the operation | movement of the switching process of the refrigerator of embodiment of this invention. The time chart which shows an example of operation | movement of the rapid cooling mode of the refrigerator of embodiment of this invention

<First Embodiment>
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing the refrigerator of the first embodiment. The refrigerator 1 is provided with a refrigerator compartment 3, a freezer compartment 4, and a vegetable compartment 5 in order from above the heat insulating box 2. The refrigerator compartment 3 stores the stored items in a refrigerator, and the freezer compartment 4 stores the stored items in a frozen state. The vegetable room 5 is maintained at a higher temperature than the refrigerated room 3 and refrigerates stored items such as vegetables.

  The refrigerator compartment 3 is opened and closed by a pivotable door 3a pivoted at one end. The freezer compartment 4 and the vegetable compartment 5 are opened and closed by drawer type doors 4a and 5a formed integrally with a storage case (not shown), respectively.

  Cold air passages 7 and 8 communicating with each other via a damper 15 are provided on the back surfaces of the freezer compartment 4 and the refrigerator compartment 3. The cold air passages 7 and 8 are provided with a freezer compartment fan 12 and a refrigerator compartment fan 13 for circulating cold air, respectively. Below the freezer compartment fan 12, an evaporator 11 for generating cold air is disposed. A defrost heater 16 that performs defrosting of the evaporator 11 is disposed below the evaporator 11. The upper surface of the defrost heater 16 is covered with a heater cover 16a. The heater cover 16a prevents the defrost heater 16 from being broken due to the defrost water dripping onto the defrost heater 16.

  The cold air passage 7 has an outlet 7 a for discharging cold air to the freezer compartment 4 and an outlet 7 b for discharging cold air from the freezer compartment 4. In the cold air passage 8, a discharge port 8 a for discharging cold air to the refrigerator compartment 3 is opened. In addition, a communication path (not shown) that connects the refrigerator compartment 3 and the vegetable compartment 5 is provided. The vegetable compartment 5 has an outlet 7c through which cold air flows out.

  A machine room 6 is provided behind the vegetable room 5, and a compressor 10 that operates a refrigeration cycle is installed in the machine room 6. The refrigerant flows through a refrigerant pipe (not shown) by driving the compressor 10, and the evaporator 11 connected to the compressor 10 through the refrigerant pipe is maintained at a low temperature.

  When the freezer compartment fan 12 is driven, the cold air exchanged with the evaporator 11 flows through the cold air passage 7. Further, when the damper 15 is opened, cold air flows through the cold air passage 8. The cold air flowing through the cold air passage 7 and the cold air passage 8 is discharged into the freezer compartment 4 and the refrigerator compartment 3 through the discharge ports 7a and 8a, respectively.

  The cold air discharged from the discharge port 7a circulates in the freezer compartment 4 to cool the stored item, and returns to the cold air passage 7 through the outlet port 7b. The cold air discharged from the discharge port 8a flows through the refrigerator compartment 3 to cool the stored items, and flows into the vegetable compartment 5 through the communication path (not shown). The cold air that has flowed into the vegetable compartment 5 flows through the vegetable compartment 5 to cool the stored items, and returns to the cold air passage 7 through the outlet 7c.

  FIG. 2 is a block diagram showing the configuration of the refrigerator 1. The refrigerator 1 includes a control unit 20 that controls each unit. The control unit 20 includes a compressor 10, a freezer compartment fan 12, a refrigerator compartment fan 13, a damper 15, a defrost heater 16, an operation unit 21, an evaporator temperature sensor 22, a refrigerator compartment temperature sensor 23, a freezer compartment temperature sensor 24, and an outside. The temperature sensor 25 and the current detection unit 26 are connected.

  The rotation speed of the compressor 10 is variably controlled by the control unit 20. The operation unit 21 is provided on the door 3a of the refrigerating room 3, and performs temperature setting of the refrigerating room 3. At this time, the set temperature of the refrigerator compartment 3 is set to, for example, “strong”, “medium”, and “weak” by the notch.

  The evaporator temperature sensor 22 is installed in the vicinity of the evaporator 11 and detects the ambient temperature of the evaporator 11. The refrigerator compartment temperature sensor 23 detects the temperature inside the refrigerator compartment 3. The freezer temperature sensor 24 detects the temperature in the freezer compartment 4. The outside air temperature sensor 25 is installed on the upper surface of the heat insulating box 2 and detects the outside air temperature.

  The current detection unit 26 detects the drive current of the compressor 10. When the drive current of the compressor 10 becomes higher than a predetermined value, the compressor 10 is determined to be in an overload state. Therefore, the current detection unit 26 constitutes an overload detection unit that detects an overload state of the compressor 10. An overload detection unit that detects the shell temperature of the compressor 10 and the pressure on the refrigerant inflow side is provided, and when the detection result of the overload detection unit becomes higher than a predetermined value, it is determined that the compressor 10 is overloaded. Also good.

  FIG. 3 is a flowchart showing an operation when the refrigerator 1 is turned on. When the power of the refrigerator 1 is turned on, it is determined in step # 11 whether the ambient temperature of the evaporator 11 detected by the evaporator temperature sensor 22 is 0 ° C. or higher. When the ambient temperature of the evaporator 11 is not 0 ° C. or higher, the process proceeds to step # 14.

  If the ambient temperature of the evaporator 11 is 0 ° C. or higher, it is determined in step # 12 whether or not the outside air temperature detected by the outside air temperature sensor 25 is 35 ° C. or higher. If the outside air temperature is not 35 ° C. or higher, the process proceeds to step # 14. When the outside air temperature is 35 ° C. or higher, a rapid cooling mode to be described later is performed in step # 13. Rapid cooling (pull-down operation) immediately after power-on is performed in the rapid cooling mode. When the rapid cooling mode ends, the process proceeds to step # 14. In step # 14, the normal mode is performed.

  Table 1 shows the operating state of each part in the normal mode and the rapid cooling mode. In the normal mode, the compressor 10, the refrigerator compartment fan 13, the refrigerator compartment fan 12, and the damper 15 are controlled according to the room temperature of the refrigerator compartment 3 and the freezer compartment 4.

  That is, when the freezer compartment 4 exceeds the upper limit temperature as detected by the freezer temperature sensor 24, the compressor 10 and the freezer compartment fan 12 are driven. Moreover, if the refrigerator compartment 3 exceeds upper limit temperature by the detection of the refrigerator compartment temperature sensor 23, the damper 15 will be opened and the compressor 10 and the refrigerator compartment fan 13 will be driven.

  The compressor 10 is variable between 1600 rpm and 4200 rpm according to the temperature of the refrigerator compartment 3 or the freezer compartment 4. The freezer compartment fan 12 rotates at a predetermined rotational speed (for example, 2000 rpm). The refrigerator compartment fan 13 rotates at a predetermined rotational speed.

  When the refrigerator compartment 3 is lowered to the lower limit temperature, the damper 15 is closed and the refrigerator compartment fan 13 is stopped. Further, when the freezer compartment 4 is lowered to the lower limit temperature, the compressor 10 and the freezer compartment fan 12 are stopped. The upper limit temperature and the lower limit temperature of the refrigerator compartment 3 are determined based on the set temperature set by the notch of the operation unit 21.

  In the rapid cooling mode, a plurality of stages that are variable according to the overload state and the non-overload state of the compressor 10 are provided. The first to fifth stages form a plurality of heat load stages with different heat loads on the evaporator 11. The fifth to eighth stages form a plurality of cooling capacity stages having different set rotational speeds N0 of the compressor 10. In the first to fifth stages, the set rotational speed N0 of the compressor 10 is the same or higher at a stage one stage higher than the stage with a low thermal load of the evaporator 11.

  The heat load on the evaporator 11 is varied by opening / closing the damper 15 and the rotation speed of the freezer compartment fan 12. Therefore, the damper 15 and the freezer compartment fan 12 constitute a heat load variable unit that varies the heat load on the evaporator 11.

  In the first stage, the damper 15 is closed, the refrigerator compartment fan 13 and the freezer compartment fan 12 are stopped, and the set rotational speed N0 of the compressor 10 is set to 1600 rpm.

  In the second stage, the damper 15 is closed, the refrigerator compartment fan 13 is stopped, and the set rotational speed N0 of the compressor 10 is set to 2000 rpm. At this time, the freezer compartment fan 12 is switched between a stopped state and a low speed rotation (for example, 1000 rpm) according to the ambient temperature of the evaporator 11 by a switching process (see FIG. 6) described later. Since the second stage has a period during which the freezer compartment fan 12 rotates at a low speed, the heat load of the evaporator 11 is higher than that of the first stage.

  In the third stage, the refrigerator compartment fan 13 is stopped and the freezer compartment fan 12 is rotated at a low speed, and the set rotational speed N0 of the compressor 10 is set to 2000 rpm. At this time, the open / close state of the damper 15 is switched according to the ambient temperature of the evaporator 11 by a switching process (see FIG. 6) described later. Since the third stage has a period in which the freezer compartment fan 12 always rotates at a low speed and opens the damper 15, the heat load of the evaporator 11 is higher than that of the second stage.

  In the fourth stage, the refrigerator compartment fan 13 is stopped and the set rotational speed N0 of the compressor 10 is set to 2000 rpm. At this time, the freezer compartment fan 12 is switched between a low-speed rotation and a high-speed rotation (for example, 2000 rpm) according to the ambient temperature of the evaporator 11 by a switching process described later (see FIG. 6). The damper 15 is opened and closed according to the temperature of the refrigerator compartment 3 corresponding to the “weak” notch, regardless of the setting notch of the operation unit 21. Since the fourth stage has a period in which the damper 15 is opened and closed according to the temperature of the refrigerator compartment 3 and the freezer compartment fan 12 rotates at a high speed, the thermal load of the evaporator 11 is higher than that of the third stage.

  In the fifth stage to the eighth stage, the refrigerator compartment fan 13 is stopped and the freezer compartment fan 12 rotates at high speed. The damper 15 is opened and closed according to the temperature of the refrigerator compartment 3 corresponding to the “weak” notch, regardless of the setting notch of the operation unit 21. Further, the set rotational speed N0 of the compressor 10 is set to 2600 rpm, 3200 rpm, 3900 rpm, and 4200 rpm for the fifth to eighth stages, respectively. In the fifth stage to the eighth stage, since the freezer compartment fan 12 always rotates at a high speed, the heat load of the evaporator 11 is higher than that of the fourth stage.

  FIG. 4 is a flowchart showing the operation in the rapid cooling mode. When the rapid cooling mode is started, 1 is assigned to the counter i indicating each stage in step # 21. In step # 22, the driving condition of the first stage indicated by the counter i is set based on Table 1 described above, and the operation of the first stage is started.

  In step # 23, it is determined whether or not the freezer compartment 4 detected by the freezer temperature sensor 24 has become equal to or lower than a predetermined temperature (−13 ° C. in the present embodiment). When the temperature of the freezer compartment 4 becomes −13 ° C. or lower, the rapid cooling mode is terminated and the process returns to the flowchart of FIG.

  If the temperature of the freezer compartment 4 is higher than −13 ° C., it is determined in step # 24 whether or not 6 hours have elapsed since the start of the rapid cooling mode. When 6 hours have elapsed from the start of the rapid cooling mode, the rapid cooling mode is terminated and the process returns to the flowchart of FIG.

  When 6 hours have not elapsed since the start of the rapid cooling mode, the process proceeds to step # 25, where it is determined whether or not the defrosting operation by the defrosting heater 16 has been started. When the defrosting operation is started, the rapid cooling mode is terminated and the process returns to the flowchart of FIG. When the defrosting operation is not started, the process proceeds to step # 26.

  In step # 26, it is determined whether or not the counter i is 8 which is the maximum value of the stage. When the counter i is 8, the process proceeds to step # 30, and when the counter i is 7 or less, the process proceeds to step # 27.

  In step # 27, it is determined whether or not the non-overload state of the compressor 10 detected by the current detection unit 26 has continued for a predetermined non-overload time (10 minutes in the present embodiment). When the non-overload state of the compressor 10 continues for 10 minutes or more, the process proceeds to step # 29. When the non-overload state of the compressor 10 has not continued for 10 minutes or more, the process proceeds to step # 28.

  In step # 28, the ambient temperature of the evaporator 11 detected by the evaporator temperature sensor 22 continues for a predetermined low temperature time (2 minutes in this embodiment) or more and lower than the predetermined temperature (-5 ° C. in this embodiment). It is determined whether or not. The low temperature time is set to be shorter than the non-overload time. When the ambient temperature of the evaporator 11 continues for 2 minutes or more and becomes -5 ° C. or less, the process proceeds to step # 29. When the ambient temperature of the evaporator 11 is higher than −5 ° C., or when −5 ° C. or lower is shorter than 2 minutes, the process proceeds to step # 30.

  In step # 29, the counter i is incremented. In step # 22, the stage driving condition corresponding to the counter i is set, and the operation of the stage is performed. Accordingly, a non-overload transition operation for shifting to a heat load stage in which the evaporator 11 has a high heat load or a cooling capacity stage in which the compressor 10 has a high set rotational speed N0 is performed according to the determinations in steps # 27 and # 28.

  In step # 30, it is determined whether or not the counter i is 1, which is the minimum value of the stage. When the counter i is 1, the process proceeds to step # 23, and when the counter i is 2 or more, the process proceeds to step # 31. In step # 31, it is determined whether or not the overload state of the compressor 10 detected by the current detection unit 26 has continued for a predetermined overload time (2 minutes in the present embodiment). When the overload state of the compressor 10 continues for 2 minutes or more, the process proceeds to step # 32. When the overload state of the compressor 10 does not continue for 2 minutes or more, the process proceeds to step # 23.

  In step # 32, stage determination processing is performed. FIG. 5 shows the operation of the stage discrimination process. In step # 41, the value of the counter i is determined, and the process branches according to the counter i. If it is determined in step # 41 that the counter i is 8, the process proceeds to step # 42. In step # 42, it is determined whether or not the actual rotational speed Nc of the compressor 10 is equal to or higher than 3900 rpm which is the set rotational speed N0 of the seventh stage. When the actual rotational speed Nc of the compressor 10 is lower than 3900 rpm, the process proceeds to step # 43. When the actual rotational speed Nc of the compressor 10 is 3900 rpm or more, 7 is substituted into the counter i in step # 47, and the process returns to step # 22 in FIG.

  If it is determined in step # 41 that the counter i is 7, the process proceeds to step # 43. In step # 43, it is determined whether or not the actual rotation speed Nc of the compressor 10 is equal to or higher than 3200 rpm which is the set rotation speed N0 of the sixth stage. When the actual rotational speed Nc of the compressor 10 is lower than 3200 rpm, the process proceeds to step # 44. When the actual rotational speed Nc of the compressor 10 is 3200 rpm or more, 6 is assigned to the counter i in step # 48, and the process returns to step # 22 in FIG.

  If it is determined in step # 41 that the counter i is 6, the process proceeds to step # 44. In step # 44, it is determined whether or not the actual rotational speed Nc of the compressor 10 is equal to or higher than 2600 rpm which is the set rotational speed N0 of the fifth stage. When the actual rotational speed Nc of the compressor 10 is lower than 2600 rpm, the process proceeds to step # 45. When the actual rotational speed Nc of the compressor 10 is 2600 rpm or more, 5 is assigned to the counter i in step # 49, and the process returns to step # 22 in FIG.

  If it is determined in step # 41 that the counter i is 5, the process proceeds to step # 45. In step # 45, it is determined whether or not the actual rotational speed Nc of the compressor 10 is equal to or higher than 2000 rpm, which is the set rotational speed N0 of the fourth stage. When the actual rotational speed Nc of the compressor 10 is lower than 2000 rpm, the process proceeds to step # 46. When the actual rotational speed Nc of the compressor 10 is 2000 rpm or more, 4 is assigned to the counter i in step # 50, and the process returns to step # 22 in FIG.

  If it is determined in step # 41 that the counter i is 4, the process proceeds to step # 46. In step # 46, it is determined whether or not the actual rotational speed Nc of the compressor 10 is equal to or higher than 1600 rpm which is the set rotational speed N0 of the first stage. When the actual rotation speed Nc of the compressor 10 is lower than 1600 rpm, the process proceeds to step # 52. When the actual rotational speed Nc of the compressor 10 is 1600 rpm or more, 3 is assigned to the counter i in step # 51, and the process returns to step # 22 in FIG.

  If the counter i is 2 in step # 41, the process proceeds to step # 52. In step # 52, 1 is assigned to the counter i, and the process returns to step # 22 in FIG. If the counter i is 3 in step # 41, the process proceeds to step # 53, 2 is substituted into the counter i, and the process returns to step # 22 in FIG.

  Then, in step # 22 of FIG. 4, the stage drive condition corresponding to the counter i is set and the operation of the stage is performed, and steps # 22 to # 32 are repeated. Therefore, the process proceeds to the stage determination process according to the determination in step # 31, and the overload transition operation is performed to shift to the heat load stage where the heat load of the evaporator 11 is low or the cooling capacity stage where the set rotational speed N0 is low. .

  At this time, in the fifth to eighth stages, the stage determination process shifts to a stage having a set rotational speed N0 lower than the actual rotational speed Nc when the overload of the compressor 10 is detected. The compressor 10 may not reach the set rotational speed N0 in an overload state. For this reason, it can transfer to the stage of the setting rotation speed N0 lower than the actual rotation speed Nc at the time of detection of an overload, and can escape the overload state of the compressor 10 rapidly.

  The overload transition operation may be performed immediately when the overload state of the compressor 10 is detected in step # 31. However, by providing a predetermined overload time, it is possible to prevent the evaporator 11 from being shifted to a stage having a low thermal capacity or cooling capacity due to a temporary overload of the compressor 10. Thereby, the freezer compartment 4 and the refrigerator compartment 3 can be cooled rapidly. The overload time is set to a time shorter than the time during which the compressor 10 can be continuously operated in an overload state.

  Further, in the flowchart of FIG. 4, when the compressor 10 detects an abnormal overload state that causes damage, the compressor 10 is stopped and restarted from step # 21 after a predetermined time (for example, 6 minutes) has elapsed. . As an abnormal overload state, the rotation speed of the compressor 10 is abnormally decreased, the drive current of the compressor 10 is abnormally increased, the shell temperature of the compressor 10 is abnormally increased, and the element temperature of the drive circuit that drives the compressor 10 is abnormal. The rise etc. are mentioned.

  FIG. 6 shows the operation of switching processing for switching the operation state of the freezer compartment fan 12 or the damper 15 according to the ambient temperature of the evaporator 11 in the second, third, and fourth stages, respectively. Note that the control of FIG. 6 is performed in parallel with the operation flow of FIGS. In step # 61, the value of the counter i is determined, and the process branches according to the counter i.

  If it is determined in step # 61 that the counter i is the second stage of 2, the process proceeds to step # 62 and the freezer compartment fan 12 is stopped. If it is determined in step # 61 that the counter i is the third stage of 3, the process proceeds to step # 63 and the damper 15 is closed. If it is determined in step # 61 that the counter i is the fourth stage of 4, the process proceeds to step # 64, and the freezer compartment fan 12 rotates at a low speed.

  In step # 65, the process waits until a predetermined time (60 seconds in the present embodiment) elapses after the execution of steps # 62 to # 64. When 60 seconds elapse after execution of steps # 62 to # 64, the value of counter i is determined at step # 66, and the process branches according to counter i.

  If the counter i is 2 in step # 66, the process proceeds to step # 67 and the freezer compartment fan 12 rotates at a low speed. If the counter i is 3 in step # 66, the process proceeds to step # 68 and the damper 15 is opened. If the counter i is 4 in step # 66, the process proceeds to step # 69, and the freezer compartment fan 12 rotates at high speed.

  In step # 70, the process waits until a predetermined time (10 seconds in this embodiment) elapses after the execution of steps # 67 to # 69. When 10 seconds elapse after execution of steps # 67 to # 69, the process proceeds to step # 71. In step # 71, it waits until the ambient temperature of the evaporator 11 becomes more than predetermined temperature (in this embodiment, -5 degreeC). When the ambient temperature of the evaporator 11 becomes −5 ° C. or higher, the process proceeds to step # 61. Then, Steps # 61 to # 71 are repeated.

  Thereby, in the second stage, the freezer compartment fan 12 rotates at a low speed while the ambient temperature of the evaporator 11 is lower than −5 ° C., and when it reaches −5 ° C. or higher, the freezer compartment fan 12 is temporarily stopped. In the third stage, the damper 15 is opened in a state where the ambient temperature of the evaporator 11 is lower than −5 ° C., and the damper 15 is once closed when the temperature becomes −5 ° C. or higher. In the fourth stage, the freezer compartment fan 12 rotates at a high speed while the ambient temperature of the evaporator 11 is lower than −5 ° C., and once it reaches −5 ° C. or higher, the freezer compartment fan 12 once rotates at a low speed.

  As described above, when the ambient temperature of the evaporator 11 is equal to or higher than a predetermined temperature, the heat load variable units such as the freezer compartment fan 12 and the damper 15 are controlled so as to temporarily reduce the heat load of the evaporator 11. Thereby, it can be made difficult to make the compressor 10 into an overload state. Therefore, the number of overload transfer operations can be reduced, and the rapid cooling mode stage can be quickly advanced to the upper level. That is, the refrigerator 1 can be rapidly and rapidly cooled.

  FIG. 7 shows an example of a time chart of each part in the rapid cooling mode. 7, (a) is an open / closed state of the damper 15, (b) is a driving state of the freezer compartment fan 12, (c) is an overload detection state of the compressor 10, (d) is each stage, and (e) is a state. The temperature of each part is shown. 7E, R is the temperature of the refrigerator compartment 3 detected by the refrigerator compartment temperature sensor 23, F is the temperature of the freezer compartment 4 detected by the freezer compartment temperature sensor 24, and E1 is the evaporator temperature sensor 22. It is the detected ambient temperature of the evaporator 11. Moreover, E2 of the figure has shown the surface temperature of the evaporator 11 for reference.

  When the rapid cooling mode is started at time t0, the operation of the first stage is performed. Thereby, the compressor 10 is driven in a state where the freezer compartment fan 12 is stopped and the damper 15 is closed, and the ambient temperature E1 of the evaporator 11 is lowered. At this time, the compressor 10 is temporarily overloaded, but the overload transition operation is not performed because the overloaded state is shorter than 2 minutes.

  When the non-overload state of the compressor 10 continues for 10 minutes in the first stage at time t1, the second stage is shifted to by the non-overload transition operation. Thus, the freezer compartment fan 12 is repeatedly stopped and rotated at a low speed according to the ambient temperature E1 of the evaporator 11 by the switching process (see FIG. 6).

  When the non-overload state of the compressor 10 continues for 10 minutes (non-overload time) in the second stage at time t2, the third stage is shifted to the third stage by the non-overload transition operation. Thereby, the freezer compartment fan 12 rotates at low speed, and the damper 15 is opened and closed according to the ambient temperature E1 of the evaporator 11 by the switching process (see FIG. 6).

  When the overload state of the compressor 10 continues in the third stage at time t3 for 2 minutes (overload time), an overload transition operation is performed, and the transition to the second stage is performed based on the actual rotational speed Nc of the compressor 10. .

  When the non-overload state of the compressor 10 continues in the second stage at time t4 for 10 minutes, the state shifts to the third stage by the non-overload transition operation. At this time, the compressor 10 is temporarily overloaded, but the overload transition operation is not performed because the overloaded state is shorter than 2 minutes.

  When the non-overload state of the compressor 10 continues for 10 minutes in the third stage at time t5, the fourth stage is shifted to by the non-overload transition operation. Thereby, the damper 15 is opened, and the freezer compartment fan 12 is repeatedly rotated at low speed and at high speed according to the ambient temperature E1 of the evaporator 11 by the switching process (see FIG. 6).

  When the non-overload state of the compressor 10 continues for 10 minutes in the fourth stage at time t6, the process shifts to the fifth stage by the non-overload transition operation. Thereby, the freezer compartment fan 12 rotates at high speed.

  Thereafter, when the non-overload state of the compressor 10 continues for 10 minutes in the fifth stage, the process proceeds to the sixth stage. Similarly, the seventh and eighth stages are shifted depending on the non-overload state of the compressor 10.

  According to this embodiment, the current detection unit 26 (overload detection unit) that detects an overload of the compressor 10, the damper 15 that changes the thermal load of the evaporator 11, and the freezer compartment fan 12 (thermal load variable unit) Is provided. And a non-overload transition operation for shifting the heat load of the evaporator 11 to a higher stage (heat load stage) when the non-overload state of the compressor 10 continues for a non-overload time in the rapid cooling mode; The overload transfer operation for transferring the thermal load of the evaporator 11 to a lower stage when the 10 overload state is reached is repeated.

  As a result, when the non-overload state of the compressor 10 continues during the rapid cooling mode, the stage gradually shifts to a stage where the evaporator 11 has a high thermal load. For this reason, even if the temperature of the evaporator 11 is high at the time of pull-down operation etc., the freezer compartment 4 can be cooled rapidly. Further, when the compressor 10 is overloaded, the thermal load of the evaporator 11 can be reduced by the overload transition operation, and the compressor 10 can be protected. Therefore, the convenience of the refrigerator 1 can be improved.

  Further, the freezer compartment fan 12 is driven and controlled so that the ambient temperature of the evaporator 11 is lower than a predetermined temperature in the second stage and the fourth stage. In the third stage, the damper 15 is opened and closed so that the ambient temperature of the evaporator 11 is lower than a predetermined temperature. Thereby, the thermal load of the evaporator 11 is finely varied while monitoring the ambient temperature of the evaporator 11 in each stage.

  For this reason, it can suppress that the compressor 10 will be in an overload state for a long time immediately after transfering to the stage with the high thermal load of the evaporator 11 by non-overload transfer operation | movement. Therefore, the non-overload transition operation and the overload transition operation are frequently repeated to prevent the freezer compartment 4 from being cooled, and the freezer compartment 4 can be cooled more quickly.

  Further, when the ambient temperature of the evaporator 11 continues for a low temperature period shorter than the non-overload time and becomes lower than the predetermined temperature, the non-overload transition operation is performed. When the ambient temperature of the evaporator 11 is continuously low, it is determined that the load on the compressor 10 is still light. For this reason, even if it is a case where low temperature time shorter than non-overload time passes, non-overload transfer operation | movement can be performed and the freezer compartment 4 can be cooled more rapidly.

  In addition, a heat load variable unit that varies the heat load of the evaporator 11 can be easily realized by changing the driving state by deceleration and acceleration including stopping of the freezer compartment fan 12.

  Further, the damper 15 for opening and closing the cool air passages 7 and 8 between the refrigerator compartment 3 and the evaporator 11 having a temperature higher than that of the freezer compartment 4 easily realizes a heat load variable section that changes the heat load of the evaporator 11. be able to.

  Further, it is possible to easily realize an overload detection unit that detects an overload of the compressor 10 by detecting the driving current of the compressor 10, the shell temperature of the compressor 10, or the pressure on the refrigerant inflow side of the compressor 10. it can.

  Further, the fifth to eighth stages form different cooling capacity stages with different set rotational speeds N0 of the compressor 10. Then, the non-overload transition operation shifts to a stage having a high set rotational speed N0 (that is, a stage having a high cooling capacity), and the overload transition operation lowers the actual rotational speed Nc when the overload of the compressor 10 is detected. The stage shifts to a stage having a set rotational speed N0 (ie, a stage having a low cooling capacity). Thereby, the overload state of the compressor 10 can be quickly escaped.

Second Embodiment
Next, the refrigerator 1 of 2nd Embodiment is demonstrated. In the present embodiment, an opening / closing member formed by a damper or the like is disposed at one or both of the discharge port 7 a and the outlet 7 b provided on the back surface of the freezer compartment 4. In addition, an opening / closing member formed by a damper or the like is disposed at the outlet 7 c provided in the vegetable compartment 5. Other parts are the same as those in the first embodiment.

  By closing each open / close member, the freezer compartment 4, the vegetable compartment 5, and the cold air passage 7 are blocked. In the refrigerator 1 having a large volume of the freezer compartment 4, even if the freezer compartment fan 12 is stopped and the damper 15 is closed, the compressor 10 may continue to be overloaded because the freezer compartment 4 has a large thermal load. is there.

  In such a case, a stage in which each of the opening / closing members is closed can be provided as a stage further before the first stage in the first embodiment. In this stage, since only the cold air passage 7 becomes a heat load, it is possible to eliminate the possibility that the refrigerator having a large volume of the freezer compartment 4 cannot proceed from the first stage to the stage having a high heat load.

  Similarly, you may provide the opening-closing member which consists of a damper etc. in the communicating path which connects the refrigerator compartment 3 and the vegetable compartment 5. Thereby, the thermal load downstream from the damper 15 can be controlled, and the compressor 10 can be hardly overloaded.

<Third Embodiment>
Next, the refrigerator 1 of 3rd Embodiment is demonstrated. In the refrigerator 1 of the first embodiment and the second embodiment, the damper 15 is switched between the open state and the closed state in the rapid cooling mode, and the rotation speed of the freezer compartment fan 12 is switched between the low speed rotation and the high speed rotation. In the present embodiment, the opening angle of the damper 15 is varied during the rapid cooling mode, and the rotation speed of the freezer compartment fan 12 is switched to more stages than the first and second embodiments at each stage. By these, the heat load of the evaporator 11 can be controlled more finely. Therefore, the refrigerator 1 can be rapidly cooled more quickly while making it difficult to place the compressor 10 in an overloaded state.

  In the first to third embodiments, the rapid cooling mode is performed at the time of pulling down immediately after the refrigerator 1 is turned on. However, when quick cooling is required at the end of the defrosting operation or storage of a high-temperature stored item. The rapid cooling mode may be performed.

  According to this invention, it can utilize for the refrigerator provided with the rapid cooling mode which cools a storage room rapidly.

DESCRIPTION OF SYMBOLS 1 Refrigerator 2 Heat insulation box 3 Refrigerating room 4 Freezing room 5 Vegetable room 6 Machine room 7, 8 Cold air passage 10 Compressor 11 Evaporator 12 Freezing room fan 13 Refrigerating room fan 15 Damper 16 Defrost heater 20 Control part 21 Operation part 22 Evaporator temperature sensor 23 Refrigerating room temperature sensor 24 Freezer room temperature sensor 25 Outside air temperature sensor 26 Current detection unit

Claims (5)

  A compressor that operates a refrigeration cycle; an evaporator that is connected to the compressor to cool the first storage chamber; a thermal load variable unit that varies a thermal load of the evaporator in a plurality of thermal load stages; and the compression An overload detection unit that detects an overload of the compressor, and when the non-overload state of the compressor continues for a predetermined non-overload time, the thermal load of the evaporator is increased by the thermal load variable unit Non-overload transition operation for transitioning to the thermal load stage, and overload transition for transitioning the thermal load of the evaporator to a lower thermal load stage by the thermal load variable unit when detecting an overload of the compressor A refrigerator provided with a quenching mode having an operation.   The refrigerator according to claim 1, wherein the heat load of the evaporator is varied so that the ambient temperature of the evaporator is lower than a predetermined temperature in the predetermined heat load stage.   2. The non-overload transition operation is performed when the ambient temperature of the evaporator continues for a low temperature period shorter than the non-overload time and becomes lower than a predetermined temperature. 2. The refrigerator according to 2.   4. The fan according to claim 1, further comprising a fan that sends cold air heat-exchanged with the evaporator to the first storage chamber, wherein the thermal load variable unit varies a driving state of the fan. The refrigerator described.   A second storage chamber that is cooled by the evaporator and maintained at a temperature higher than that of the first storage chamber; and a damper that opens and closes a cold air passage between the evaporator and the second storage chamber. The refrigerator according to claim 4, wherein the portion changes an open / close state of the damper.

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