Refrigerator

Abstract

In a refrigerator in which a thermostat inputs an external power supply voltage to an inverter control circuit, power consumption of the inverter control circuit is reduced. A refrigerator includes: a housing in which a storage compartment is formed; a thermostat which is provided with a first external terminal to which an external power supply voltage is input and a second external terminal, and which is turned on or off in accordance with the temperature of the storage chamber; a compressor; and an inverter control circuit provided with an input terminal electrically connected to the second external terminal, the inverter control circuit driving a drive circuit for driving the compressor by means of an AC voltage input to the input terminal, and the inverter control circuit controlling the drive circuit to drive the compressor when the AC voltage is input to the input terminal. The inverter control circuit determines the rotational speed of the compressor during this operation, operates the compressor at the rotational speed during a period when the external power supply voltage is input to the input terminal, and stops the drive circuit and the compressor during a period when the external power supply voltage is not input to the input terminal.

Description

Technical Field

[0001] The present disclosure relates to a refrigerator. Background Art

[0002] WO 2020 / 090752 discloses a refrigerator. In this refrigerator, when the temperature of the wall surface of the freezer compartment rises above the upper limit temperature, the thermostat outputs the external power supply voltage to terminal T, and when the temperature is lower than the lower limit temperature, the thermostat does not output the external power supply voltage to terminal T.

[0003] The inverter control circuit performs arc starting control of the inverter based on the external power supply voltage input to the temperature signal input terminal through terminal T, thereby controlling the operation and rotational speed of the motor of the variable speed compressor, and adjusting the temperature of the storage compartment in this way (paragraph 0022). Summary of the Invention

[0004] In the refrigerator disclosed in WO 2020 / 090752, even when the temperature of the wall surface of the freezer compartment is lower than the lower limit temperature, the inverter control circuit remains in the energized state. Therefore, the power consumption of the inverter control circuit increases.

[0005] The present invention has been completed in view of this problem. An object of one aspect of the present disclosure is to reduce the power consumption of the inverter control circuit, for example, in a refrigerator in which the thermostat inputs the external power supply voltage to the inverter control circuit.

[0006] A refrigerator according to one embodiment of the present disclosure includes: a housing forming a storage compartment; a thermostat having a first external terminal for inputting an external power supply voltage and a second external terminal, and being in a conducting state in which the second external terminal is in conduction with the first external terminal or a cut-off state in which the second external terminal is not in conduction with the first external terminal according to the temperature of the storage compartment; a compressor; and an inverter control circuit having an input terminal electrically connected to the second external terminal, the inverter control circuit driving a drive circuit for driving the compressor by an AC voltage input to the input terminal, and when the AC voltage is input to the input terminal, the inverter control circuit determines the rotational speed of the compressor during the current operation, and during the period when the external power supply voltage is input to the input terminal, the compressor is operated at the rotational speed, and during the period when the external power supply voltage is not input to the input terminal, the inverter control circuit stops the drive circuit and the compressor. Brief Description of the Drawings

[0007] Figure 1 It is a front view schematically showing the refrigerator of the first embodiment with the door closed.

[0008] Figure 2Is a front view schematically showing the door of the refrigerator according to the first embodiment in an open state.

[0009] Figure 3 Is a perspective view schematically showing the refrigerator according to the first embodiment.

[0010] Figure 4 Is a circuit diagram of the refrigerator according to the first embodiment.

[0011] Figure 5 Is a perspective view schematically showing the thermostat included in the refrigerator according to the first embodiment.

[0012] Figure 6 Is a block diagram of the inverter control circuit included in the refrigerator according to the first embodiment.

[0013] Figure 7 Is a diagram showing information for controlling the rotational speed of the compressor included in the refrigerator according to the first embodiment.

[0014] Figure 8 Is a flowchart showing the operation process of the refrigerator according to the first embodiment.

[0015] Figure 9 Is a diagram showing the first table used in the first example, second example, and third example of the process for determining the rotational speed of the compressor included in the refrigerator according to the first embodiment during the current operation.

[0016] Figure 10 Is a diagram showing the second table used in the first example of the process for determining the rotational speed of the compressor included in the refrigerator according to the first embodiment during the current operation.

[0017] Figure 11 Is a diagram showing the third table used in the first example of the process for determining the rotational speed of the compressor included in the refrigerator according to the first embodiment during the current operation.

[0018] Figure 12 Is a diagram showing the content of the first example of the process for determining the rotational speed of the compressor included in the refrigerator according to the first embodiment during the current operation.

[0019] Figure 13 Is a diagram showing the fourth table used in the second example of the process for determining the rotational speed of the compressor included in the refrigerator according to the first embodiment during the current operation.

[0020] Figure 14 Is a diagram showing the content of the second example of the process for determining the rotational speed of the compressor included in the refrigerator according to the first embodiment during the current operation.

[0021] Figure 15This is a diagram showing a fifth table used in a third example of a process for determining the rotational speed of a compressor during the current operation of a refrigerator according to the first embodiment.

[0022] Figure 16 This is a block diagram of a defrosting mechanism that the refrigerator according to the first embodiment may also include. Detailed Embodiment

[0023] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In addition, for the drawings, the same or equivalent elements are denoted by the same reference numerals, and repeated descriptions are omitted.

[0024] 1 First Embodiment 1.1 Structure of the Refrigerator Figure 1 This is a front view schematically showing the door of the refrigerator according to the first embodiment in a closed state. Figure 2 This is a front view schematically showing the door of the refrigerator according to the first embodiment in an open state.

[0025] Refrigerators include constant-speed compressor type refrigerators that control the on / off of a constant-speed compressor with a fixed rotational speed by the output of a thermostat, and variable-speed compressor type refrigerators that control the on / off and rotational speed of a variable-speed compressor with a variable rotational speed by the output of an inverter. Constant-speed compressor type refrigerators have a simple structure but do not have high power-saving performance. In contrast, variable-speed compressor type refrigerators have a complex structure but have high power-saving performance. Figures 1 to 4 The refrigerator 1 according to the shown first embodiment is a variable-speed compressor type refrigerator that replaces the constant-speed compressor included in a constant-speed compressor type refrigerator with a variable-speed compressor. Thus, most of the refrigerator 1 can be constituted by general components that constitute a constant-speed compressor type refrigerator. This can reduce the development cost of the refrigerator 1.

[0026] As Figure 1 and Figure 2 shown, the refrigerator 1 includes a cabinet 11, a shelf 12, a tray 13, a knob 14, and a door 15.

[0027] The cabinet 11 has a box-like shape. A storage compartment 11A and an opening 11B are formed in the cabinet 11. The storage compartment 11A is formed inside the cabinet 11. The opening 11B is formed on the front surface of the cabinet 11. Heat insulating materials are filled in each wall surface of the cabinet 11. Thus, the cabinet 11 prevents heat exchange between the storage compartment 11A formed inside the cabinet 11 and the outside of the cabinet 11. When the door 15 is opened, the storage compartment 11A is exposed to the outside of the cabinet 11 through the opening 11B. When the door 15 is closed, the storage compartment 11A is sealed by the cabinet 11 and the door 15.

[0028] The storage compartment 11A includes a freezer compartment 11D and a refrigerator compartment 11E. The freezer compartment 11D is disposed vertically above the refrigerator compartment 11E. The refrigerator compartment 11E communicates with the freezer compartment 11D.

[0029] The inner wall surrounding the freezer compartment 11D also serves as an evaporator that forms part of the refrigeration cycle. The evaporator causes the refrigerant that forms part of the refrigeration cycle to evaporate, thereby absorbing heat from the air inside the freezer compartment 11D. As a result, the evaporator cools the freezer compartment 11D and the refrigerator compartment 11E that communicates with the freezer compartment 11D.

[0030] The shelf 12 is housed in the refrigerator compartment 11E. The shelf 12 has a plate-like shape. The shelf 12 separates the space above the shelf 12 in the vertical direction from the space below the shelf 12 in the vertical direction. The items to be stored are placed on the shelf 12.

[0031] The tray 13 is housed in the refrigerator compartment 11E. The tray 13 has a box-like shape. The tray 13 separates the internal space of the tray 13 from the external space of the tray 13. The items to be stored are received in the tray 13.

[0032] The knob 14 receives an operation for adjusting the set temperature. The knob 14 can also be replaced with an operation member other than a knob. The knob 14 is disposed on the side of the freezer compartment 11D.

[0033] The door 15 is coupled to the cabinet 11. The door 15 is openable and closable and can move between a position where the opening 11B is not closed and a position where the opening 11B is closed. The door 15 is disposed at the position where the opening 11B is not closed when it is open. The door 15 is disposed at the position where the opening 11B is closed when it is closed.

[0034] A storage pocket 15A is formed on the door 15. The storage pocket 15A is formed on the inner surface of the door 15. The items to be stored are received in the storage pocket 15A.

[0035] Figure 3 is a perspective view schematically showing the refrigerator of the first embodiment.

[0036] As Figure 3 shown, the refrigerator 1 includes a cabinet 11, a chassis 16, a grounding terminal 17, a compressor 18, and a power cord 19.

[0037] The chassis 16 has a frame-like shape. A bottom space 16A is formed on the chassis 16. The bottom space 16A is disposed outside the cabinet 11 and is exposed at the back of the refrigerator 1. The chassis 16 supports the grounding terminal 17 and the compressor 18.

[0038] The grounding terminal 17 is applied with a ground potential. The grounding terminal 17 is preferably grounded. The grounding terminal 17 is disposed in the bottom space 16A.

[0039] The compressor 18 compresses the refrigerant that constitutes the refrigeration cycle. The compressor 18 is disposed in the bottom space 16A. The compressor 18 is a variable-speed compressor. Therefore, the rotational speed of the compressor 18 is variable.

[0040] The power cord 19 is plugged and unplugged at the socket. When the power cord 19 is inserted into the socket, an external power supply voltage is introduced from the socket. The introduced external power supply voltage is an alternating voltage supplied by a commercial power supply.

[0041] 1.2 Circuit of the refrigerator Figure 4 It is the circuit diagram of the refrigerator of the first embodiment.

[0042] As Figure 4 shown, the refrigerator 1 includes a ground terminal 17, a compressor 18, a power cord 19, a first terminal pair 20, a surge absorption circuit 21, a second terminal pair 22, a thermostat 23, a third terminal pair 24, a terminal 25, a detection unit 26, an inverter control circuit 27, a door switch 28, and an interior light 29. The first terminal pair 20 includes a first terminal 20X and a second terminal 20Y. The second terminal pair 22 includes a first terminal 22X and a second terminal 22Y. The third terminal pair 24 includes a first terminal 24X and a second terminal 24Y.

[0043] The ground terminal 17, the compressor 18, the first terminal pair 20, the surge absorption circuit 21, the second terminal pair 22, the third terminal pair 24, the terminal 25, and the inverter control circuit 27 are disposed in the bottom space 16A. The first terminal pair 20, the second terminal pair 22, the third terminal pair 24, and the terminal 25 are disposed at positions where wiring is led out from the cabinet 11. The thermostat 23, the door switch 28, and the interior light 29 are disposed inside the cabinet 11. The detection unit 26 is disposed outside the cabinet 11.

[0044] As Figure 4 shown, the power cord 19 includes a plug 40, a first electric wire 41, and a second electric wire 42. The plug 40 includes a first plug piece 51 and a second plug piece 52.

[0045] The first plug piece 51 and the second plug piece 52 can be respectively inserted into and pulled out from the first insertion port and the second insertion port of the socket. When the first plug piece 51 and the second plug piece 52 are respectively inserted into the first insertion port and the second insertion port, they are electrically connected to the first insertion port and the second insertion port respectively.

[0046] One end of the first electric wire 41 is combined with the first plug piece 51 and is electrically connected to the first plug piece 51. One end of the second electric wire 42 is combined with the second plug piece 52 and is electrically connected to the second plug piece 52. Thus, the power cord 19 guides the external power supply voltage from the first plug piece 51 and the second plug piece 52 to the other ends of the first electric wire 41 and the second electric wire 42.

[0047] The first terminal 20X is combined with the other end of the first electric wire 41 and is electrically connected to the other end of the first electric wire 41. The second terminal 20Y is combined with the other end of the second electric wire 42 and is electrically connected to the other end of the second electric wire 42. Thus, the power supply line 19 guides the external power supply voltage from the first insertion port and the second insertion port to the first terminal 20X and the second terminal 20Y.

[0048] As Figure 4 shown, the surge absorption circuit 21 includes an input terminal pair 61, an output terminal pair 62, and a grounding terminal 63. The input terminal pair 61 includes a first input terminal 61X and a second input terminal 61Y. The output terminal pair 62 includes a first output terminal 62X and a second output terminal 62Y.

[0049] The surge absorption circuit 21 electrically connects the first input terminal 61X and the second input terminal 61Y to the first output terminal 62X and the second output terminal 62Y, respectively. Thus, the surge absorption circuit 21 outputs the external power supply voltage input to the first input terminal 61X and the second input terminal 61Y from the first output terminal 62X and the second output terminal 62Y.

[0050] The surge absorption circuit 21 includes a surge response component. The surge response component conducts current when an overvoltage is applied. The surge response component is also referred to as a surge absorption component, a surge absorption element, etc. The surge response component is a varistor, a lightning protection element, a surge absorber, etc. The surge response component is inserted between the first input terminal 61X and the second input terminal 61Y. Thus, the surge absorption circuit 21 absorbs the surge input to the first input terminal 61X and the second input terminal 61Y to suppress the output of the surge from the first output terminal 62X and the second output terminal 62Y.

[0051] The first input terminal 61X and the second input terminal 61Y are electrically connected to the first terminal 20X and the second terminal 20Y, respectively. The first terminal 22X and the second terminal 22Y are electrically connected to the first output terminal 62X and the second output terminal 62Y, respectively. Thus, the surge absorption circuit 21 outputs the external power supply voltage guided by the power supply line 19 from the first terminal 22X and the second terminal 22Y. In addition, the surge absorption circuit 21 suppresses the output of the surge guided by the power supply line 19 from the first terminal 22X and the second terminal 22Y. Thus, it is possible to suppress a circuit after the first terminal 22X and the second terminal 22Y from malfunctioning due to a surge. In particular, it is possible to suppress the inverter control circuit 27 from malfunctioning due to a surge. The grounding terminal 63 is electrically connected to the grounding terminal 17. Thus, the surge absorption circuit 21 prevents the first terminal 22X and the second terminal 22Y from exceeding a specified upper limit voltage with respect to the ground potential connected to the grounding terminal 17.

[0052] The surge absorption circuit 21 can also be omitted. When the surge absorption circuit 21 is omitted, the first terminal 22X and the second terminal 22Y are respectively combined with the first terminal 20X and the second terminal 20Y, and are respectively electrically connected to the other ends of the first electric wire 41 and the second electric wire 42. In this case, the first terminal pair 20 and the second terminal pair 22 can be omitted.

[0053] As Figure 4 shown, the thermostat 23 includes a first external terminal 71, a second external terminal 72, and a grounding terminal 73.

[0054] The thermostat 23 is arranged in the storage room 11A. The thermostat 23 is in a conducting state where the second external terminal 72 is conducting with the first external terminal 71 or in a non-conducting state where the second external terminal 72 is not conducting with the first external terminal 71 according to the temperature of the storage room 11A. The thermostat 23 has the above-mentioned knob 14. When the temperature of the storage room 11A is higher than the upper limit temperature of the set temperature adjusted by the knob 14, the thermostat 23 becomes conductive, and when the temperature of the storage room 11A is lower than the lower limit temperature of the set temperature, the thermostat 23 becomes non-conductive.

[0055] The first external terminal 71 is electrically connected to the first terminal 22X. Thus, the external power supply voltage is input to the first external terminal 71. The grounding terminal 73 is electrically connected to the terminal 25. The terminal 25 is electrically connected to the grounding terminal 17. Thus, the grounding terminal 73 is electrically connected to the grounding terminal 17 via the terminal 25.

[0056] The first terminal 24X is electrically connected to the second external terminal 72. The second terminal 24Y is electrically connected to the second terminal 22Y.

[0057] The detection unit 26 detects the external air temperature of the refrigerator 1 and outputs a signal representing the detected temperature. The detection unit 26 is a temperature sensor or the like.

[0058] As Figure 4 shown, the inverter control circuit 27 includes an input terminal pair 81, an output terminal group 82, and a grounding terminal 83. The input terminal pair 81 includes a first input terminal 81X and a second input terminal 81Y. The output terminal group 82 includes a first output terminal 82X, a second output terminal 82Y, and a third output terminal 82Z.

[0059] While an external power supply voltage is input to the first input terminal 81X and the second input terminal 81Y, the inverter control circuit 27 generates a drive voltage from the input external power supply voltage and outputs the generated drive voltage from the first output terminal 82X, the second output terminal 82Y, and the third output terminal 82Z. While no external power supply voltage is input to the first input terminal 81X and the second input terminal 81Y, the inverter control circuit 27 does not output a drive voltage from the first output terminal 82X, the second output terminal 82Y, and the third output terminal 82Z.

[0060] The first input terminal 81X is electrically connected to the first terminal 24X. Thus, the first input terminal 81X is electrically connected to the second external terminal 72 via the first terminal 24X and is electrically connected to the first terminal 22X via the thermostat 23. The second input terminal 81Y is electrically connected to the second terminal 24Y. Thus, the second input terminal 81Y is electrically connected to the second terminal 22Y via the second terminal 24Y. Thus, while the thermostat 23 is in the conducting state, an external power supply voltage is input to the first input terminal 81X and the second input terminal 81Y. On the other hand, while the thermostat 23 is in the non-conducting state, no external power supply voltage is input to the first input terminal 81X and the second input terminal 81Y. The grounding terminal 83 is electrically connected to the grounding terminal 17. In addition, the second terminal 24Y may be omitted. In this case, the second input terminal 81Y is electrically connected to the second terminal 22Y within the bottom space 16A.

[0061] The inverter control circuit 27 is electrically connected to the detection unit 26. Thus, the inverter control circuit 27 can receive a signal indicating the outside air temperature of the refrigerator 1. The inverter control circuit 27 can control the drive voltage based on the temperature indicated by the received signal.

[0062] As Figure 4 shown, the compressor 18 includes an input terminal group 91 and a grounding terminal 92. The input terminal group 91 includes a first input terminal 91X, a second input terminal 91Y, and a third input terminal 91Z.

[0063] While a drive voltage is input to the first input terminal 91X, the second input terminal 91Y, and the third input terminal 91Z, the compressor 18 operates. During operation, the compressor 18 rotates at a speed corresponding to the waveform of the input drive voltage to compress the refrigerant. On the other hand, when no drive voltage is input to the first input terminal 91X, the second input terminal 91Y, and the third input terminal 91Z, the compressor 18 stops. During the stop, the compressor 18 does not rotate and does not compress the refrigerant.

[0064] The first input terminal 91X, the second input terminal 91Y, and the third input terminal 91Z are electrically connected to the first output terminal 82X, the second output terminal 82Y, and the third output terminal 82Z, respectively. Thus, the compressor 18 operates during the period when the drive voltages are output from the first output terminal 82X, the second output terminal 82Y, and the third output terminal 82Z. On the other hand, the compressor 18 stops during the period when no drive voltage is output from the first output terminal 82X, the second output terminal 82Y, and the third output terminal 82Z. The grounding terminal 92 is electrically connected to the ground terminal 17.

[0065] Thus, during the period when the temperature in the storage chamber 11A is higher than the set upper limit temperature and becomes below the set lower limit temperature (during the period when the thermostat 23 is in the conducting state and the external power supply voltage is input to the first input terminal 81X and the second input terminal 81Y), the inverter control circuit 27 operates the compressor 18. The inverter control circuit 27 stops the compressor 18 during the period when the temperature in the storage chamber 11A becomes below the set lower limit temperature and becomes higher than the set upper limit temperature (during the period when the thermostat 23 is in the non-conducting state and the external power supply voltage is not input to the first input terminal 81X and the second input terminal 81Y). During the period when the compressor 18 stops, the external power supply voltage is not input to the inverter control circuit 27. Thus, the power consumption of the inverter control circuit 27 can be reduced. For example, the power consumption of the inverter control circuit 27 can be reduced by about 35%. In addition, the probability of the inverter control circuit 27 failing due to a surge can be reduced. The reason why the probability of the inverter control circuit 27 failing due to a surge can be reduced when no external power supply voltage is input to the inverter control circuit 27 is that the probability of the inverter control circuit 27 failing due to a surge when it is energized is higher than the probability of the inverter control circuit 27 failing due to a surge when it is not energized. Thus, the absorption capacity of the surge absorption circuit 21 can be reduced, or the surge absorption circuit 21 can be omitted.

[0066] As Figure 4 shown, the door switch 28 includes a first terminal 111 and a second terminal 112.

[0067] The door switch 28 is in a conducting state where the second terminal 112 is in conduction with the first terminal 111 or a non-conducting state where the second terminal 112 is not in conduction with the first terminal 111 according to the position of the door 15. The door switch 28 is in the conducting state during the period when the door 15 is disposed at a position that does not close the opening 11B. On the other hand, the door switch 28 is in the non-conducting state during the period when the door 15 is disposed at a position that closes the opening 11B.

[0068] The first terminal 111 is electrically connected to the first terminal 22X.

[0069] As Figure 4 shown, the indoor lamp 29 includes a first terminal 121 and a second terminal 122.

[0070] While an external power supply voltage is not input to the first terminal 121 and the second terminal 122, the interior lamp 29 is turned off. While an external power supply voltage is input to the first terminal 121 and the second terminal 122, the interior lamp 29 is turned on.

[0071] The first terminal 121 is electrically connected to the second terminal 112. Thus, the first terminal 121 is electrically connected to the first terminal 22X via the door switch 28. The second terminal 122 is electrically connected to the second terminal 22Y. Thus, while the door switch 28 is in the on state, an external power supply voltage is input to the first terminal 121 and the second terminal 122. While the door switch 28 is in the off state, an external power supply voltage is not input to the first terminal 121 and the second terminal 122.

[0072] Thus, the interior lamp 29 is turned on while the door 15 is disposed at a position where the opening 11B is not closed and an external power supply voltage is input to the first terminal 121 and the second terminal 122. The interior lamp 29 is turned off while the door 15 is disposed at a position where the opening 11B is closed and no external power supply voltage is input to the first terminal 121 and the second terminal 122.

[0073] In the above description, the electrical connection between the first element and the second element includes two cases: the first element is directly connected to the second element and the first element is connected to the second element via a wiring.

[0074] 1.3 Thermostat Figure 5 FIG. is a perspective view schematically showing a thermostat included in the refrigerator according to the first embodiment.

[0075] As Figure 5 shown, the thermostat 23 includes a knob 14, a first external terminal 71, a second external terminal 72, a capillary tube 74, and a housing 75.

[0076] The knob 14, the first external terminal 71, and the second external terminal 72 are disposed outside the housing 75.

[0077] The capillary tube 74 has a linear shape and is flexible. One end of the capillary tube 74 is disposed inside the housing 75. The other end of the capillary tube 74 has a temperature detection unit 131. The temperature detection unit 131 is fixed inside the storage chamber 11A. Thus, the temperature detection unit 131 can detect the temperature of the storage chamber 11A. For example, the temperature detection unit 131 is fixed to a wall surface surrounding the freezer compartment 11D.

[0078] The housing 75 is made of a conductive material. The housing 75 includes a grounding terminal 73. Thus, the housing 75 is grounded via the terminal 25 and the grounding terminal 17. Thus, it is possible to suppress noise from entering the inside of the housing 75 from the outside of the housing 75.

[0079] 1.4 Inverter control circuit Figure 6 It is a block diagram of the inverter control circuit included in the refrigerator of the first embodiment.

[0080] As Figure 6 shown, the inverter control circuit 27 includes a drive circuit 141, a control unit 142, and a storage unit 143.

[0081] The drive circuit 141 generates a drive voltage based on the external power supply voltage input to the first input terminal 81X and the second input terminal 81Y, and outputs the generated drive voltage from the first output terminal 82X, the second output terminal 82Y, and the third output terminal 82Z according to a control signal from the control unit 142. The drive circuit 141 includes a converter, an inverter, and an auxiliary circuit.

[0082] The control unit 142 controls the drive circuit 141 to control the output drive voltage. Thus, the control unit 142 controls the rotational speed of the compressor 18. The control unit 142 writes information required to control the rotational speed of the compressor 18 during the next and subsequent operations into the storage unit 143, and reads information required to control the rotational speed of the compressor 18 during the current operation from the storage unit 143. The control unit 142 is composed of a processor. The processor reads a program stored in the storage unit 143 and executes the read program to perform processing required to control the rotational speed of the compressor 18. All or part of the processing required to control the rotational speed of the compressor 18 may also be executed by a dedicated electronic circuit.

[0083] The storage unit 143 stores information required to control the rotational speed of the compressor 18 and a program executed by the processor. The storage unit 143 is composed of a memory, a storage device, etc.

[0084] The drive circuit 141, the control unit 142, and the storage unit 143 operate relying on the external power supply voltage input to the first input terminal 81X and the second input terminal 81Y. In addition, the control unit 142 and the storage unit 143 can still operate relying on the backup function within a short period (about several seconds) immediately after a change from a state where an external power supply voltage is input to the first input terminal 81X and the second input terminal 81Y to a state where no external power supply voltage is input.

[0085] 1.5 Information for controlling the rotational speed of the compressor Figure 7 It is a diagram showing information for controlling the rotational speed of the compressor included in the refrigerator of the first embodiment.

[0086] As Figure 7As shown, in order to control the rotational speed 151 of the compressor 18 during the current operation, the inverter control circuit 27 uses the operation time 152 of the compressor 18 during past operations. When the inverter control circuit 27 uses the operation time 152 during past operations, it controls the rotational speed 151 during the current operation based on the operation time 152 during past operations. For example, the inverter control circuit 27 controls the rotational speed 151 during the current operation based on the operation time 162 of the compressor 18 during the last operation. As the operation time 152 during past operations becomes longer, the inverter control circuit 27 increases the rotational speed 151 during the current operation. Thus, when the cooling capacity of the refrigeration cycle during the past operation of the compressor 18 is insufficient and the operation time 152 during past operations becomes longer, the cooling capacity of the refrigeration cycle during the current operation of the compressor 18 can be increased. Thus, the operation time during the current operation of the compressor 18 can be shortened.

[0087] As the operation time 152 during past operations is longer than a preset stable operation time, the inverter control circuit 27 increases the rotational speed 151 during the current operation. As the operation time 152 during past operations is shorter than the stable operation time, the inverter control circuit 27 decreases the rotational speed 151 during the current operation. By repeating such operations, the rotational speed of the compressor 18 can be converged to a stable rotational speed, the operation time of the compressor 18 can be made close to the stable operation time, and the operation rate of the compressor 18 can be made close to the stable operation rate. The stable rotational speed is, for example, 1400 - 2800 rpm (depending on the external air temperature and the load inside the refrigerator), the stable operation time is, for example, 27 minutes, and the stable operation rate is, for example, 65%. That is to say, when the operation time of the previous compressor 18 is longer than the stable operation time or the operation rate of the compressor 18 is higher than the stable operation rate, the inverter control circuit 27 increases the rotational speed of the compressor 18, shortens the operation time of the compressor 18, and decreases the operation rate of the compressor 18. On the other hand, when the operation time of the previous compressor 18 is shorter than the stable operation time or the operation rate of the compressor 18 is lower than the stable operation rate, the inverter control circuit 27 decreases the rotational speed of the compressor 18, prolongs the operation time of the compressor 18, and increases the operation rate of the compressor 18. As a result, the inverter control circuit 27 makes the operation time of the compressor 18 close to the stable operation time and makes the operation rate of the compressor 18 close to the stable operation rate. At this time, the rotational speed of the compressor 18 also approaches the stable rotational speed.

[0088] As Figure 7As shown, in order to control the rotational speed 151 of the compressor 18 during the current operation, the inverter control circuit 27 can use the external air temperature 156 of the refrigerator 1 during the current operation detected by the detection unit 26. When the inverter control circuit 27 uses the external air temperature 156 during the current operation, it controls the rotational speed 151 during the current operation based on the external air temperature 156 during the current operation. For example, as the external air temperature 156 during the current operation rises, the inverter control circuit 27 increases the rotational speed 151 during the current operation. Thus, when the external air temperature rises and the cooling capacity of the refrigeration cycle may be insufficient during the current operation of the compressor 18, the cooling capacity of the refrigeration cycle can be improved.

[0089] As Figure 7 As shown, in order to control the rotational speed 151 of the compressor 18 during the current operation, the inverter control circuit 27 can use the external air temperature 154 during the past operation of the compressor 18 detected by the detection unit 26 and the external air temperature 156 during the current operation of the compressor 18 detected by the detection unit 26. When the inverter control circuit 27 uses the external air temperature 154 during the past operation and the external air temperature 156 during the current operation, it controls the rotational speed 151 during the current operation based on the external air temperature 154 during the past operation and the external air temperature 156 during the current operation. For example, the inverter control circuit 27 controls the rotational speed 151 during the current operation based on the external air temperature 164 during the last operation of the compressor 18 detected by the detection unit 26 and the external air temperature 156 during the current operation. As the increase in the external air temperature 154 from the past operation to the external air temperature 156 during the current operation rises, the inverter control circuit 27 increases the rotational speed 151 during the current operation. For example, as the increase in the external air temperature 164 during the last operation to the external air temperature 156 during the current operation rises, the inverter control circuit 27 increases the rotational speed 151 during the current operation. Thus, when the external air temperature rises and the cooling capacity of the refrigeration cycle may be insufficient during the current operation of the compressor 18, the cooling capacity of the refrigeration cycle can be improved.

[0090] As Figure 7As shown, in order to control the rotational speed 151 of the compressor 18 during the current operation, the inverter control circuit 27 can use the stop time 153 of the compressor 18 at the previous stop. When the inverter control circuit 27 uses the stop time 153 at the previous stop, it controls the rotational speed 151 during the current operation based on the stop time 153 at the previous stop and the operation time 152 during the previous operation. For example, the inverter control circuit 27 controls the rotational speed 151 during the current operation based on the stop time 163 at the last stop of the compressor 18 and the operation time 162 during the last operation. As the stop time 153 at the previous stop becomes longer, the inverter control circuit 27 decreases the rotational speed 151 during the current operation. For example, as the stop time 163 at the last stop becomes longer, the inverter control circuit 27 decreases the rotational speed 151 during the current operation. In addition, during the period when the compressor 18 is stopped, the external power supply voltage is not input to the inverter control circuit 27. Therefore, when the inverter control circuit 27 uses the stop time 153 at the previous stop, in order to perform the process required to write the stop time of the compressor 18 into the storage unit 143, the control unit 142 and the storage unit 143 are backed up by a backup battery or the like. The stop time 153 at the previous stop may not be the measured time, but may also be an estimated time or a fixed time. Additionally, when the control unit 142 can communicate with the outside, the current time can be obtained by communicating with an external server, router, etc., and the obtained time is stored in the storage unit 143, thereby calculating the stop time 163 at the last stop of the compressor 18.

[0091] As Figure 7 shown, in order to control the rotational speed 151 of the compressor 18 during the current operation, the inverter control circuit 27 can use the rotational speed 155 of the compressor 18 during the previous operation. When the inverter control circuit 27 uses the rotational speed 155 during the previous operation, it controls the rotational speed 151 during the current operation based on the rotational speed 155 during the previous operation. For example, the inverter control circuit 27 controls the rotational speed 151 during the current operation based on the rotational speed 165 of the compressor 18 during the last operation. As the rotational speed 155 during the previous operation increases, the inverter control circuit 27 increases the rotational speed 151 during the current operation. For example, as the rotational speed 165 during the last operation increases, the inverter control circuit 27 increases the rotational speed 151 during the current operation.

[0092] The rotational speed 155 during the previous operation can be determined by a speed step associated with that speed 155. The rotational speed 151 during the current operation can be determined by a speed step associated with that speed 151. Specific examples of these speed steps will be described below.

[0093] The inverter control circuit 27 may perform the process for determining the rotation speed 151 during the current operation using a calculation formula, a table, or both a calculation formula and a table.

[0094] 1.6 Refrigerator Operation Figure 8 This is a flowchart showing the flow of operations of the refrigerator according to the first embodiment.

[0095] Refrigerator 1 Execution Figure 8 The steps from step S101 to step S107 are shown.

[0096] In step S101, a change occurs from a state where the external power supply voltage is not input to the first input terminal 81X and the second input terminal 81Y to a state where the external power supply voltage is input to the first input terminal 81X and the second input terminal 81Y. This change occurs when the temperature of the storage room 11A rises to a temperature higher than the set upper limit temperature and the thermostat 23 changes from the off state to the on state, or when the plug 40 is inserted into the socket when the temperature of the storage room 11A is higher than the set upper limit temperature.

[0097] In the next step S102, the control unit 142 acquires information for controlling the rotation speed 151 during the current operation. When using the operation time 152 during the past operation, the stop time 153 during the past stop, the external temperature 154 during the past operation, and the rotation speed 155 during the past operation, the control unit 142 reads the operation time 152 during the past operation, the stop time 153 during the past stop, the external temperature 154 during the past operation, and the rotation speed 155 during the past operation from the storage unit 143, respectively. When using the external temperature 156 during the current operation, the control unit 142 receives a signal indicating the external temperature 156 during the current operation from the detection unit 26.

[0098] Through steps S101 and S102, the control unit 142 can synchronously obtain information for controlling the rotational speed 151 during this operation when a change occurs from a state where the external power supply voltage is not input to the first input terminal 81X and the second input terminal 81Y to a state where the external power supply voltage is input to the first input terminal 81X and the second input terminal 81Y.

[0099] In the next step S103 , the control unit 142 determines the rotation speed 151 during the current operation based on the acquired information.

[0100] In the next step S104, the control unit 142 starts rotating the compressor 18. The control unit 142 continues rotating the compressor 18 at the determined rotation speed 151 for this operation from the start of the rotation of the compressor 18 in step S104 until the rotation of the compressor 18 ends in step S106.

[0101] Through steps S101 to S104, the control unit 142 does not rotate the compressor 18 during the period when the external power supply voltage is not input to the first input terminal 81X and the second input terminal 81Y. In addition, when the state changes from the state where the external power supply voltage is not input to the first input terminal 81X and the second input terminal 81Y to the state where the external power supply voltage is input to the first input terminal 81X and the second input terminal 81Y, the control unit 142 starts to rotate the compressor 18 in conjunction. At this time, the control unit 142 determines the rotation speed 151 during this operation based on the acquired information.

[0102] In the next step S105, the control unit 142 determines whether a change is detected from a state where an external power supply voltage is input from the first input terminal 81X and the second input terminal 81Y to a state where an external power supply voltage is not input from the first input terminal 81X and the second input terminal 81Y. This change occurs when the temperature of the storage chamber 11A drops below the set lower limit temperature and the thermostat 23 changes from the on state to the off state. If it is determined that such a change is not detected, step S105 is executed again. Thus, before such a change is detected, the control unit 142 continues to rotate the compressor 18. If it is determined that such a change is detected, step S106 is executed.

[0103] In step S106, since the external power supply voltage is no longer input to the first input terminal 81X and the second input terminal 81Y, the driving voltage is no longer output from the first output terminal 82X, the second output terminal 82Y, and the third output terminal 82Z. Therefore, the compressor 18 stops rotating.

[0104] In the next step S107, the control unit 142 writes information for controlling the rotation speed of the compressor 18 in the next operation and after operation into the storage unit 143. When using the rotation speed 151 during the current operation, the external temperature 156 during the current operation, and the operation time during the current operation, the control unit 142 writes the rotation speed 151 during the current operation, the external temperature 156 during the current operation, and the operation time during the current operation into the storage unit 143, respectively. The control unit 142 writes the information into the storage unit 143 during the time when the backup function played when the voltage input to the first input terminal 81X and the second input terminal 81Y is lower than the reference is effective. Through the above steps, the information for controlling the rotation speed during the next operation and after operation can be written into the storage unit 143.

[0105] 1.7 First example of the process for determining the rotational speed of the compressor during the present operation Figure 9 It is a diagram showing a first table used in the first, second, and third examples of the process for determining the rotational speed of the compressor provided in the refrigerator of the first embodiment during the present operation.

[0106] As Figure 9 shown, the first table 171 includes candidates for speed steps "1",..., "12" and candidates for rotational speeds "1200 rpm",..., "3900 rpm".

[0107] The first table 171 corresponds the candidates for rotational speeds "1200 rpm",..., "3900 rpm" to the candidates for speed steps "1",..., "12" respectively.

[0108] Figure 10 It is a diagram showing a second table used in the first example of the process for determining the rotational speed of the compressor provided in the refrigerator of the first embodiment during the present operation.

[0109] As Figure 10 shown, the second table 172 includes candidates for temperature ranges "less than 0°C",..., "40°C or higher" and candidates for standard operation times "10 minutes",..., "60 minutes".

[0110] The second table 172 corresponds the candidates for standard operation times "10 minutes",..., "60 minutes" to the candidates for temperature ranges "less than 0°C",..., "40°C or higher" respectively.

[0111] Figure 11 It is a diagram showing a third table used in the first example of the process for determining the rotational speed of the compressor provided in the refrigerator of the first embodiment during the present operation.

[0112] As Figure 11 shown, the third table 173 includes candidates for ranges of operation time differences "less than -15 minutes",..., "15 minutes or more" and candidates for speed step change amounts "-2",..., "+2".

[0113] The third table 173 corresponds the candidates for speed step change amounts "-2",..., "+2" to the candidates for ranges of operation time differences "less than -15 minutes",..., "15 minutes or more" respectively.

[0114] Figure 12 It is a diagram showing the content of the first example of the process for determining the rotational speed of the compressor provided in the refrigerator of the first embodiment during the present operation.

[0115] As Figure 12As shown, the control unit 142 refers to the second table 172 and determines the candidate of the standard operation time corresponding to the candidate of the temperature range to which the external air temperature 156 at the time of the current operation belongs as the standard operation time 181.

[0116] In addition, the control unit 142 calculates the operation time difference 182 obtained by subtracting the determined standard operation time 181 from the operation time 162 at the time of the previous operation obtained ("operation time 162 at the time of the previous operation" - "standard operation time 181").

[0117] In addition, the control unit 142 refers to the third table 173 and determines the candidate of the speed step change amount corresponding to the candidate of the operation time difference range to which the calculated operation time difference 182 belongs as the speed step change amount 183.

[0118] In addition, the control unit 142 adjusts the speed step 184 at the time of the previous operation obtained according to the change indicated by the determined speed step change amount 183, and determines the speed step 185 at the time of the current operation of the compressor 18.

[0119] In addition, the control unit 142 refers to the first table 171 and determines the candidate of the rotation speed corresponding to the candidate of the speed step that matches the determined speed step 185 at the time of the current operation as the rotation speed 151 at the time of the current operation.

[0120] Thus, the control unit 142 can determine the rotation speed 151 at the time of the current operation based on the external air temperature 156 at the time of the current operation, the operation time 162 at the time of the previous operation, and the speed step 184 at the time of the previous operation.

[0121] 1.8 Second Example of Processing for Determining the Rotation Speed of the Compressor at the Time of the Current Operation Figure 13 It is a diagram showing a fourth table used in the second example of the processing for determining the rotation speed of the compressor provided in the refrigerator of the first embodiment at the time of the current operation.

[0122] As Figure 13 shown, the fourth table 174 includes candidates for the operation time change amount range "less than -5 minutes",..., "5 minutes or more" and candidates for the speed step change amount "-1",..., "+1".

[0123] The fourth table 174 corresponds the candidates for the speed step change amount "-1",..., "+1" to the candidates for the operation time change amount range "less than -5 minutes",..., "5 minutes or more" respectively.

[0124] Figure 14 It is a diagram showing the content of the second example of the processing for determining the rotation speed of the compressor provided in the refrigerator of the first embodiment at the time of the current operation.

[0125] As shown Figure 14 in the figure, the control unit 142 calculates the operation time change amount 187 obtained by subtracting the operation time 186 during the penultimate operation from the operation time 162 during the last operation obtained ("operation time 162 during the last operation" - "operation time 186 during the penultimate operation").

[0126] In addition, the control unit 142 refers to the fourth table 174 and determines the candidate of the speed step change amount corresponding to the candidate of the operation time change amount range to which the calculated operation time change amount 187 belongs as the speed step change amount 183.

[0127] In addition, the control unit 142 adjusts the speed step 184 during the last operation obtained according to the change indicated by the determined speed step change amount 183, and determines the speed step 185 during the current operation.

[0128] In addition, the control unit 142 refers to the first table 171 and determines the candidate of the rotation speed corresponding to the candidate of the speed step that is consistent with the determined speed step 185 during the current operation as the rotation speed 151 during the current operation.

[0129] Thus, the control unit 142 can determine the rotation speed 151 during the current operation based on the operation time 162 during the last operation, the operation time 186 during the penultimate operation, and the speed step 184 during the last operation.

[0130] The fourth table 174 is set such that when the operation time change amount 187 is positive and the operation time of the compressor 18 shows an increasing trend, the rotation speed 151 during the current operation increases; when the operation time change amount 187 is negative and the operation time of the compressor 18 shows a decreasing trend, the rotation speed 151 during the current operation decreases. Thus, the cooling capacity of the refrigeration cycle can be changed according to the change in the load borne by the refrigeration cycle. For example, when the number of times the door 15 is opened and closed is large, a large-capacity hot object is stored in the storage room 11A, etc., the cooling capacity of the refrigeration cycle can be improved.

[0131] The second example can be used in combination with the first example.

[0132] 1.9 Third Example of Processing for Determining the Rotation Speed of the Compressor during the Current Operation Figure 15 It is a diagram showing the fifth table used in the third example of the processing for determining the rotation speed of the compressor of the refrigerator according to the first embodiment during the current operation.

[0133] As Figure 15As shown, the fifth table 175 includes candidate "less than 0°C",..., "above 40°C" for the temperature range, candidate "less than -5 minutes",..., "above 5 minutes" for the range of change in operation time, and candidate "3",..., "11" for the speed step size.

[0134] The fifth table 175 corresponds the candidate "3",..., "11" for the speed step size to the candidate "less than 0°C",..., "above 40°C" for the temperature range respectively.

[0135] Referring to Figure 15 the table, the control unit 142 sets the candidate for the speed step size corresponding to the candidate for the temperature range to which the external air temperature 156 belongs as the speed step size during the current operation.

[0136] In addition, the control unit 142 refers to the first table 171 and determines the candidate for the rotational speed corresponding to the candidate for the speed step size that matches the determined speed step size during the current operation as the rotational speed 151 during the current operation.

[0137] Thus, the rotational speed 151 is determined only by the external air temperature 156, and thus time measurement and storage are not required.

[0138] 1.10 Defrosting Figure 16 is a block diagram of a defrosting mechanism that the refrigerator of the first embodiment may also include.

[0139] The refrigerator 1 may also include a defrosting mechanism 191 as Figure 16 shown. The defrosting mechanism 191 includes an operation time counter 201 and a defrost heater 202.

[0140] The operation time counter 201 counts the operation time during which the compressor 18 is operated. The counted operation time increases over time when the compressor 18 is operating and does not increase even over time when the compressor 18 stops. In addition, when the defrost heater 202 defrosts the storage compartment 11A, the operation time counter 201 resets the counted operation time to 0. Therefore, the operation time during which the compressor 18 has been operated since the last defrosting of the storage compartment 11A can be determined based on the counted operation time.

[0141] The defrost heater 202 synchronously defrosts the storage compartment 11A when the operation time counted by the operation time counter 201 reaches a set time. The set time is, for example, 8 hours. Thus, when the operation time of the compressor 18 becomes long and it is estimated that the storage compartment 11A has frosted, the storage compartment 11A can be defrosted.

[0142] The present disclosure is not limited to the above-described embodiments, and may be replaced with a configuration that is substantially the same as the configuration shown in the above-described embodiments, a configuration that achieves the same effect, or a configuration that can achieve the same purpose.

Claims

1. A refrigerator, characterized in that: include: a housing formed with a storage chamber; a thermostat having a first external terminal for inputting an external power supply voltage and a second external terminal, wherein the thermostat is in an on-state in which the second external terminal is in conduction with the first external terminal or in an off-state in which the second external terminal is not in conduction with the first external terminal according to the temperature of the storage chamber; compressor; as well as An inverter control circuit includes an input terminal electrically connected to the second external terminal, wherein the inverter control circuit drives a drive circuit for driving the compressor by an AC voltage input to the input terminal, and when the AC voltage is input to the input terminal, the inverter control circuit determines the speed of the compressor during this operation, operates the compressor at the speed while the external power supply voltage is input to the input terminal, and stops the drive circuit and the compressor while the external power supply voltage is not input to the input terminal.

2. The refrigerator according to claim 1, characterized in that: The inverter control circuit changes the rotation speed during the current operation based on the operation time during the past operation.

3. The refrigerator according to claim 2, characterized in that: The operating time during the past operation is the operating time during the previous operation.

4. The refrigerator according to claim 1, characterized in that: A detection unit is provided, which detects the external temperature of the refrigerator, The inverter control circuit controls the rotation speed during the current operation based on the temperature detected by the detection unit during the current operation.

5. The refrigerator according to claim 4, characterized in that: The inverter control circuit controls the rotation speed during the current operation based on a difference between a temperature detected by the detection unit during a past operation and a temperature detected by the detection unit during the current operation.

6. The refrigerator according to claim 1, characterized in that: The inverter control circuit comprises: a storage unit; and A control unit which, when a change occurs from a state in which the external power supply voltage is input to the input terminal to a state in which the external power supply voltage is not input to the input terminal, writes the operating time of the compressor during the current operation into the storage unit in a linked manner, and when a change occurs from a state in which the external power supply voltage is not input to the input terminal to a state in which the external power supply voltage is input to the input terminal, reads the operating time of the past operation from the storage unit in a linked manner.

7. The refrigerator according to claim 1, characterized in that: The inverter control circuit controls the rotation speed during the current operation based on a stop time of the compressor during a past stop and an operation time during a past operation.

8. The refrigerator according to claim 7, characterized in that: The stop time during the past stop is the stop time during the last stop.

9. The refrigerator according to claim 1, characterized in that: The inverter control circuit calculates an operation rate based on an operation time during past operation and a stop time during past stop of the compressor, and controls the rotation speed during the current operation based on the operation rate.

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