refrigerator

Abstract

To solve the problems that in a conventional refrigerator, it is difficult to control a power consumption of a refrigerator depending on the operating state of a heating unit, and there is a risk that bacteria in water in a water supply pipe may grow.SOLUTION: An ice maker 30 of a refrigerator 10 mainly comprises a water supply tank 31, an ice tray 32, an ice storage container 33, a water supply pump 34, a water supply pipe 35, and a heating unit 36. Then, a control unit 40 determines the presence or absence of water in the water supply tank 31 via an infrared sensor 44, and variably controls an energization rate to the heating unit 36 according to the determination content. With this structure, bacteria are prevented from growing in the water remaining in the water supply pipe, and a power consumption of the refrigerator 10 is suppressed.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a refrigerator equipped with an ice-making device, and particularly to a refrigerator that prevents water remaining in the water supply pipe of the ice-making device from freezing and blocking the water supply pipe, and suppresses power consumption by variably controlling the energization rate of the heating part of the ice-making device.

Background Art

[0002] Patent Document 1 discloses a conventional refrigerator. The refrigerator includes an ice-making device, and the ice-making device includes a water supply tank disposed in the refrigerating chamber, an ice tray and an ice storage case disposed in the ice-making chamber, a water supply pump and a water supply pipe for supplying water in the water supply tank to the ice tray.

[0003] In the ice-making device, a drive current is applied to the water supply pump, and the water sucked up from the water supply tank is supplied to the ice tray through the water supply pipe. And a pipe heater, which is a heating means, is disposed at a portion of the water supply pipe disposed in the ice-making chamber, and it is prevented that the water remaining in the water supply pipe freezes in the water supply pipe.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, in the conventional refrigerator, the presence or absence of water in the water supply tank is detected by a microcomputer. When it is detected that there is water in the water supply tank, the pipe heater is operated, and when it is detected that the water supply tank is empty, the pipe heater is stopped. Thus, by appropriately operating the pipe heater, the power consumption of the refrigerator is suppressed.

[0006] However, in conventional refrigerators, the pipe heater operates when there is water in the water tank. Furthermore, it is sufficient for the water supply pipe to be open at least immediately before the water supply process to the ice tray begins, and there is a problem in that it is difficult to reduce power consumption by operating the pipe heater more than necessary.

[0007] Furthermore, if the pipe heater operates more than necessary, the water supply pipes can become extremely hot, raising the temperature of the water remaining in the pipes and potentially leading to bacterial growth.

[0008] The present invention has been made in view of the above circumstances, and aims to provide a refrigerator that prevents water remaining in the water supply pipe of an ice maker from freezing and blocking the water supply pipe, and that suppresses power consumption by variably controlling the power supply rate of the heating section of the ice maker. [Means for solving the problem]

[0009] The refrigerator of the present invention comprises a water supply tank for storing water, an ice tray for making ice from the water, an ice maker for defreezing the ice made in the ice tray, a water supply pump for sucking the water from the water supply tank, a water supply pipe for sending the water sucked by the water supply pump to the ice tray, a heating unit for heating the water supply pipe, and a control unit for determining the presence or absence of water in the water supply tank and for variably controlling the power supply rate to the heating unit, wherein the control unit is characterized in that it sets the power supply rate to the heating unit before the operation of the water supply pump to be higher than the power supply rate to the heating unit after the operation of the water supply pump.

[0010] Furthermore, in the refrigerator of the present invention, the control unit first determines that the water supply tank is empty, and after a certain period of time has elapsed since maximizing the power supply rate to the heating unit, it reduces the power supply rate to the heating unit and performs a second determination of whether or not there is water in the water supply tank.

[0011] Furthermore, in the refrigerator of the present invention, the control unit determines twice in succession that the water supply tank is empty, and then, after determining that the insulated door that opens and closes the interior of the refrigerator where the water supply tank is located has not opened, it stops supplying power to the heating unit.

[0012] Furthermore, in the refrigerator of the present invention, the control unit determines twice in succession that the water supply tank is empty, and then determines that the insulated door that opens and closes the interior of the refrigerator where the water supply tank is located has opened and closed, and then after a certain period of time has elapsed since the current supply rate to the heating unit has been maximized, the current supply rate to the heating unit has been reduced, and then the water supply pump has been driven.

[0013] Furthermore, the refrigerator of the present invention comprises a compressor constituting a refrigeration cycle, and the control unit is characterized in that when the compressor is in operation, it increases the rate of power supply to the heating section compared to when the compressor is stopped.

[0014] Furthermore, in the refrigerator of the present invention, the control unit is characterized in that, when driving the water supply pump, it first operates the motor that drives the water supply pump in the reverse direction, then operates it in the forward direction, and finally operates it again in the reverse direction. [Effects of the Invention]

[0015] In the refrigerator of the present invention, the control unit sets the power supply rate to the heating unit before the water supply pump is activated to be higher than the power supply rate to the heating unit after the water supply pump is activated, and sets the power supply rate to the heating unit to a low level that prevents the water in the water supply pipe from freezing for a certain period of time after the water supply pump is activated. This control method prevents the water remaining in the water supply pipe from freezing and blocking the water supply pipe, and also reduces the power consumption of the refrigerator.

[0016] Furthermore, in the refrigerator of the present invention, the control unit determines that the water supply tank is empty on the first turn and heats the water supply pipe by maximizing the power supply rate to the heating unit. With this control method, even if the water in the water supply pipe becomes blocked due to freezing of water caused by variations in the assembly of refrigerator parts, the frozen state can be thawed and the water supply operation to the ice tray can be carried out.

[0017] Furthermore, in the refrigerator of the present invention, after determining that the water tank is empty for the first time, the control unit maximizes the power supply to the heating unit, and then, after determining that the water tank is empty for two consecutive times, stops the power supply to the heating unit under certain control conditions. With this control method, the control unit can suppress the power consumption of the refrigerator by determining that the water supply pipe is not blocked and the water tank is empty.

[0018] Furthermore, in the refrigerator of the present invention, the water supply tank is determined to be empty twice in a row, and after it is determined that the insulated door that opens and closes the interior of the refrigerator where the water supply tank is located has opened and closed, the power supply rate to the heating section is set to the maximum, and after a certain period of time has elapsed, the power supply rate to the heating section is reduced, and then the water supply pump is driven. This prevents blockage due to freezing in the water supply pipe and suppresses the water remaining in the water supply pipe from becoming hot, thereby preventing bacteria from growing in the water.

[0019] Furthermore, in the refrigerator of the present invention, the amount of heat supplied to the water supply pipe is reduced when the compressor is stopped compared to when the compressor is running. This suppresses the water remaining in the water supply pipe from becoming extremely hot, thereby preventing bacteria from multiplying in the water.

[0020] Furthermore, in the refrigerator of the present invention, when operating the water supply pump, the control unit operates the drive motor in the order of reverse, forward, and reverse. With this control method, even if water melted by heating by the heating unit remains near the tip of the water supply pipe due to surface tension, the drive motor is first operated in the reverse direction to suck up the water near the tip of the water supply pipe, thereby preventing the water from splashing onto the ice tray.

Brief Description of the Drawings

[0021] [Figure 1] These are diagrams for explaining the refrigerator according to an embodiment of the present invention. (A) is a perspective view of the refrigerator seen from the front, and (B) is a side sectional view of the refrigerator. [Figure 2] These are diagrams for explaining the refrigerator according to an embodiment of the present invention. (A) is a side sectional view for explaining the ice making device, and (B) is a block diagram showing an overview of the ice making device. [Figure 3] This is a table for explaining the ice making operation of the refrigerator according to an embodiment of the present invention. [Figure 4] This is a flowchart for explaining the ice making operation of the refrigerator according to an embodiment of the present invention. [Figure 5] This is a flowchart for explaining the ice making operation of the refrigerator according to an embodiment of the present invention.

Modes for Carrying Out the Invention

[0022] Hereinafter, the refrigerator 10 of the present embodiment will be described in detail based on the drawings. In the following description, the vertical direction indicates the height direction of the refrigerator 10, the left - right direction indicates the width direction of the refrigerator 10 seen from the front, and the front - rear direction indicates the depth direction of the refrigerator 10. Also, in the description of the present embodiment, the same reference numerals are generally used for the same members, and repeated descriptions are omitted.

[0023] FIG. 1(A) is a perspective view of the refrigerator 10 of the present embodiment seen from the front. FIG. 1(B) is a side sectional view of the refrigerator 10 of the present embodiment. FIG. 2(A) is a side sectional view for explaining the ice making device 30 disposed in the refrigerator 10 of the present embodiment. FIG. 2(B) is a block diagram for explaining the ice making device 30 of the refrigerator 10 of the present embodiment. In FIG. 1(B), the flow of cold air is indicated by arrows.

[0024] As shown in Figure 1(A), the interior of the insulated box 11 of the refrigerator 10 is used as a storage compartment, and the storage compartment is divided into a refrigerator compartment 12 (see Figure 1(B)) and a freezer compartment 13 (see Figure 1(B)) by an insulated partition wall 27 (see Figure 1(B)). The front opening of the refrigerator compartment 12 is closed by an insulated door 18 that can be opened and closed, and the front opening of the freezer compartment 13 is closed by an insulated door 19 that can be opened and closed. The insulated doors 18 and 19 are revolving doors whose right end is pivotally supported on the insulated box 11. Note that drawer doors or double doors may also be used as the insulated doors 18 and 19.

[0025] As shown in Figure 1(B), a cooling chamber 21 is partitioned behind the freezer chamber 13, and an evaporator 20 is installed in the cooling chamber 21. In addition, a machine room 14 is partitioned at the bottom rear of the insulated box 11, and a compressor 23 and other equipment are installed in the machine room 14. The evaporator 20 and compressor 23 are connected to an expansion means and a condenser (not shown) via refrigerant piping, forming a vapor compression refrigeration cycle. A defrost heater 26 is installed below the evaporator 20 to melt frost on the evaporator 20.

[0026] A blower 25 is installed at the top of the cooling chamber 21, and the cold air inside the cooling chamber 21, cooled by the evaporator 20, is blown to the refrigerator chamber 12 and the freezer chamber 13 via the blower 25. A damper 24 is interposed in the air passage to the refrigerator chamber 12.

[0027] Here, the control unit 40 (see Figure 2(B)) detects the internal temperature of the refrigerator compartment 12 using the internal temperature sensor 42 (see Figure 2(B)) and controls the opening and closing of the damper 24. It then adjusts the flow rate of cold air into the refrigerator compartment 12 to maintain a constant internal temperature. Through this control by the control unit 40, the refrigerator compartment 12 is cooled to the refrigeration temperature range. Similarly, the freezer compartment 13 is cooled to the freezing temperature range. The cold air that has cooled the refrigerator compartment 12 and the freezer compartment 13 returns to the cooling chamber 21 via the return air passage.

[0028] As shown in the figure, the insulated box 11 mainly consists of an outer box 15 made of steel plates that form the outer shape of the refrigerator 10, an inner box 16 made of a box-shaped synthetic resin plate formed inside the outer box 15, and an insulating material 17 disposed between the outer box 15 and the inner box 16. For example, foamed urethane is used as the insulating material 17.

[0029] Figure 2(A) shows the state in which the ice-making device 30 of the refrigerator 10 is installed in the refrigerator compartment 12 and the freezer compartment 13. The freezer compartment 13 is equipped with an ice storage container 33 and storage containers 38 and 39, and is divided into three levels in the height direction. Frozen foods, for example, are stored in the storage containers 38 and 39, and can be removed by sliding the storage containers 38 and 39 in the depth direction of the freezer compartment 13.

[0030] As shown in the diagram, the ice-making device 30 mainly comprises a water supply tank 31, an ice tray 32, an ice storage container 33, a water supply pump 34, a water supply pipe 35, a heating unit 36, and an ice maker 37. The water supply tank 31 stores water to be supplied to the ice tray 32 and is located on the upper surface of the insulated partition wall 27 of the refrigerator compartment 12. The user opens the insulated door 18, removes the water supply tank 31 as needed, and supplies water into the water supply tank 31.

[0031] Furthermore, a water supply pump 34 is also installed in the refrigerator compartment 12 near the water supply tank 31, and a motor 45 for the water supply pump (see Figure 2(B)) is controlled by the control unit 40. During normal ice-making operation, for example, one cycle is performed at 120-minute intervals, drawing water from the water supply tank 31 and supplying it to the ice tray 32.

[0032] The ice maker 37 is positioned above the ice storage container 33 in the freezer compartment 13 and includes a rotating twisting mechanism (not shown) that automatically drops the ice made in the ice tray 32 into the ice storage container 33, and an ice storage amount detection mechanism (not shown) that detects the amount of ice stored in the ice storage container 33. As shown in the figure, the ice tray 32 is located inside the ice maker 37, for example, below the insulating partition wall 27 and above the ice storage container 33.

[0033] The water supply pipe 35 is connected to the water supply pump 34 and is routed through the inside of the insulated partition wall 27 from the refrigerator compartment 12 to the freezer compartment 13. A pipe heater, which serves as a heating element 36, is installed on the outer surface of the water supply pipe 35 to prevent any water remaining in the pipe from freezing. As will be described in more detail later, the power supply rate to the heating element 36 is appropriately varied by the control unit 40, thereby reducing the power consumption of the refrigerator 10.

[0034] The control unit 40 constitutes an electronic control unit (ECU) that performs various calculations to control the refrigerator 10 and controls the ice-making operation of the ice-making device 30. The control unit 40 is connected to a timer 41, an internal temperature sensor 42, a door open / close sensor 43, an infrared sensor 44, a compressor 23, a motor 45 for the water supply pump 34 (hereinafter referred to as "motor 45"), a heating unit 36, an ice maker 37, and the like.

[0035] The timer 41 measures the operating and stopping times of various components of the refrigerator 10, such as the compressor 23 and the ice maker 30. The internal temperature sensor 42 measures the internal temperature of the refrigerator compartment 12 and the freezer compartment 13. The door open / close sensor 43 detects the open / closed state of the insulated doors 18 and 19 of the refrigerator compartment 12 and the freezer compartment 13. The infrared sensor 44 detects the bottom surface temperature of the ice tray 32.

[0036] Furthermore, the control unit 40 performs predetermined calculation processing based on input information from the timer 41, the internal temperature sensor 42, the door open / close sensor 43, and the infrared sensor 44, and controls the operation and stopping of the compressor 23, water supply pump 34, heating unit 36, and ice maker 37 based on said calculation processing.

[0037] Figure 3 is a table illustrating the variable control of the power supply rate to the heating unit 36 ​​during the ice-making operation of the ice-making device 30 of the refrigerator 10 in this embodiment. Figure 4 is a flowchart illustrating the ice-making operation of the ice-making device 30 of the refrigerator 10 in this embodiment, and corresponds to power supply rates A and D in Figure 3. Figure 5 is a flowchart illustrating the ice-making operation of the ice-making device 30 of the refrigerator 10 in this embodiment, and corresponds to power supply rates B and C in Figure 3. When explaining Figures 3 to 5, refer to Figures 1 and 2 and their explanations as appropriate.

[0038] As shown in Figure 3, Condition 1 for ice making operation is "operating conditions where the cooling intensity of the freezer compartment 13 is 7 or higher out of 10 levels, or in quick ice making mode or quick freezing mode, and the temperature of the freezer compartment 13 is lower than -18°C." Condition 2 for ice making operation is "operating conditions after the first empty detection of the water supply tank 31." Condition 3 for ice making operation is "operating conditions other than those described in Conditions 1 and 2." In the ice making device 30 of the refrigerator 10, the power supply rate to the heating unit 36 ​​is variably controlled depending on whether the compressor 23 is running or stopped, under the operating conditions of the refrigerator 10 described in Conditions 1 to 3 above.

[0039] Quick ice-making mode is a mode in which ice is made in a shorter cycle than normal ice-making operation, and quick freezing mode is a mode in which the freezer compartment 13 is rapidly cooled preferentially over the refrigerator compartment 12.

[0040] As illustrated, in this embodiment, the operating conditions of the refrigerator 10 under conditions 1 to 3 have four patterns, from energization rate A to energization rate D. In each of the patterns from energization rate A to energization rate D, the energization rate to the heating unit 36 ​​is higher when the compressor 23 is operating than when the compressor 23 is stopped.

[0041] When the compressor 23 is operating, the blower 25 also operates, and the cold air inside the cooling chamber 21 is circulated within the chamber, cooling the water supply pipe 35 at the same time. This increases the amount of heat generated from the heating unit 36, heating the water supply pipe 35 and preventing the water inside the water supply pipe 35 from freezing.

[0042] On the other hand, when the compressor 23 stops, the blower 25 also stops, making it more difficult for the water supply pipe 35 to cool down to at least below the internal temperature. This reduces the amount of heat generated from the heating unit 36 ​​and prevents the water supply pipe 35 from becoming excessively hot. This control method prevents bacterial growth by reducing the temperature of the water remaining in the water supply pipe 35 when the compressor 23 stops, and also reduces the power consumption of the refrigerator 10.

[0043] In the normal ice-making operation of the ice-making device 30, the water supply pump 34 is operated at intervals of 120 minutes, drawing water from the water supply tank 31 and supplying it to the ice tray 32. In the normal ice-making operation, based on a reference of 70 minutes from the previous water supply from the water supply tank 31, the power supply rate to the heating unit 36 ​​from the time of the previous water supply from the water supply tank 31 until the start of the next water supply from the water supply tank 31 is controlled to be higher than the power supply rate to the heating unit 36 ​​from the time of the previous water supply from the water supply tank 31 until the 70 minutes from the start of the next water supply from the water supply tank 31. Note that the above 70 minutes is just one example in this embodiment, and the design can be changed as needed depending on the model of the refrigerator 10 and the ice-making operation program.

[0044] Furthermore, in the four power supply rate patterns A through D, the most appropriate power supply rate is selected from the four levels of power supply rate settings, depending on the water filling status in the water supply tank 31 and the elapsed time during ice making operation.

[0045] In the first stage, the energization rate of the compressor 23 is 15% when it is running and 10% when it is stopped. In the second stage, the energization rate of the compressor 23 is 30% when it is running and 25% when it is stopped. In the third stage, the energization rate of the compressor 23 is 50% when it is running and 40% when it is stopped. In the fourth stage, the energization rate of the compressor 23 is 100% both when it is running and when it is stopped.

[0046] First, the control method for power supply level A of the refrigerator 10 will be explained using Figure 4. As shown in the figure, the control method for power supply level A is when the control unit 40 detects twice in a row, using the infrared sensor 44, that the water supply tank 31 is empty after the previous water supply operation. Steps S10 to S16 in Figure 4 correspond to the control method for power supply level A.

[0047] In step S10, at step S61 NO (see Figure 5), the control unit 40 determines, based on the detection signal from the infrared sensor 44, that the water supply operation to the ice tray 32 has not been performed twice in a row, and therefore determines that there is no water in the water supply tank 31, in other words, that it is empty.

[0048] In step S11, the control unit 40 determines whether or not the insulated door 18 of the refrigerator compartment 12 has opened based on the detection signal from the door opening / closing sensor 43. If the result of step S11 is YES, and the control unit 40 receives the detection signal and determines that the insulated door 18 of the refrigerator compartment 12 has opened, the control unit proceeds to step S17 and starts controlling the power supply rate D.

[0049] On the other hand, in step S11, if the control unit 40 determines that the insulated door 18 of the refrigerator compartment 12 is not open without receiving the above detection signal, then in step S12, the control unit 40 determines whether or not the operating status of the refrigerator 10 satisfies condition 1 above.

[0050] In step S12, if the control unit 40 determines that the operating status of the refrigerator 10 satisfies the above condition 1, the process proceeds to step S13, where it determines whether the compressor 23 is operating or not. In step S12, if the control unit 40 determines that the operating status of the refrigerator 10 does not satisfy the above condition 1, the process proceeds to step S16, where the control unit 40 stops supplying power to the heating unit 36 ​​and returns to step S11.

[0051] In step S13, if the control unit 40 determines that the compressor 23 is operating, in step S14, the control unit 40 reduces the energization rate to the heating unit 36 ​​to 30% and continues to energize it, then returns to step S11.

[0052] On the other hand, if the control unit 40 determines in step S13 that the compressor 23 has stopped, in step S15 the control unit 40 reduces the energization rate to the heating unit 36 ​​to 25% and continues to energize it, then returns to step S11.

[0053] Next, the control method for the power supply rate D of the refrigerator 10 will be explained using Figure 4. As shown in the figure, the control method for the power supply rate D is when the control unit 40 detects that the water supply tank 31 is empty after the previous water supply operation to the ice tray 32, and there is a possibility that the user has supplied water to the water supply tank 31. Steps S17 to S21 in Figure 4 correspond to the control method for the power supply rate D.

[0054] In step S17, based on the detection signal from the door opening / closing sensor 43, it is determined whether or not the insulated door 18 of the refrigerator compartment 12 has closed. If the result of step S17 is YES, and the control unit 40 determines that the insulated door 18 of the refrigerator compartment 12 has closed, then in step S18, the control unit 40 increases the power supply rate to the heating unit 36 ​​to 100% and continues to supply power.

[0055] Furthermore, if the control unit 40 determines in step S17 NO that the insulated door 18 of the refrigerator compartment 12 is not closed, the control unit 40 continues to determine the closing operation of the insulated door 18 of the refrigerator compartment 12 based on the detection signal from the door opening / closing sensor 43.

[0056] In step S19, based on the detection signal from the timer 41, it is determined whether or not 15 minutes have passed since the insulated door 18 of the refrigerator compartment 12 was closed. If the result of step S19 is YES, and the control unit 40 determines that 15 minutes have passed since the insulated door 18 of the refrigerator compartment 12 was closed, then in step S20, the control unit 40 reduces the power supply rate to the heating unit 36 ​​to 50% and continues to supply power.

[0057] Furthermore, in step S19, if the control unit 40 determines that 15 minutes have not elapsed since the insulated door 18 of the refrigerator compartment 12 was closed, the control unit 40 continues to determine the elapsed time of the 15 minutes based on the detection signal from the timer 41.

[0058] In step S21, the control unit 40 determines, based on the detection signal from the timer 41, whether or not 45 minutes have passed since the insulated door 18 of the refrigerator compartment 12 was closed. If the result of step S21 is YES, and the control unit 40 determines that 45 minutes have passed since the insulated door 18 of the refrigerator compartment 12 was closed, the process proceeds to step S30, where the control unit 40 begins controlling the power supply rate B.

[0059] Furthermore, in step S21, if the control unit 40 determines that 45 minutes have not elapsed since the insulated door 18 of the refrigerator compartment 12 was closed, the control unit 40 continues to determine the elapsed time of the 45 minutes based on the detection signal from the timer 41.

[0060] Next, the control method for the power supply rate B of the refrigerator 10 will be explained using Figure 5. As shown in the figure, the control method for power supply rate B is when the water supply tank 31 is not empty and the operating status of the refrigerator 10 meets either condition 1 or condition 3 above. Steps S30 to S49 in Figure 5 correspond to the control method for power supply rate B.

[0061] In step S30, the control unit 40 determines whether or not the ice in the ice storage container 33 is full of ice via the ice storage amount detection unit of the ice maker 37 (not shown). If, in step S30, the control unit 40 determines that the ice in the ice storage container 33 is not full of ice, then in step S31, the control unit 40 performs a de-ice operation on the ice tray 32 and then supplies water to the ice tray 32.

[0062] In step S32, the control unit 40 determines from the detection signal from the infrared sensor 44 whether or not the first water supply operation to the ice tray 32 has been performed. If, in step S32, the control unit 40 determines that the first water supply operation to the ice tray 32 has not been performed, the process proceeds to step S50, and the control unit 40 begins controlling the power supply rate C.

[0063] On the other hand, if the control unit 40 determines in step S32 that the first water supply operation to the ice tray 32 has been performed, in step S33 the control unit 40 starts the ice-making operation in the ice tray 32, and in step S34 the control unit 40 determines whether or not the operating status of the refrigerator 10 satisfies the above condition 1.

[0064] In step S34, if the control unit 40 determines that the operating status of the refrigerator 10 satisfies the above condition 1, it proceeds to step S35 to determine whether or not the compressor 23 is operating. Then, in step S35, if the control unit 40 determines that the compressor 23 is operating, in step S36 the control unit 40 continues to supply power to the heating unit 36, maintaining the power supply rate at 50%.

[0065] On the other hand, if the control unit 40 determines in step S35 that the compressor 23 has stopped, in step S37 the control unit 40 reduces the energization rate to the heating unit 36 ​​to 40% and continues to supply power.

[0066] In step S34, if the control unit 40 determines that the operating status of the refrigerator 10 does not meet the above condition 1, it proceeds to step S38 to determine whether the compressor 23 is operating or not. Then, in step S38, if the control unit 40 determines that the compressor 23 is operating, in step S39 the control unit 40 reduces the power supply rate to the heating unit 36 ​​to 15% and continues to supply power.

[0067] On the other hand, if the control unit 40 determines in step S38 NO that the compressor 23 has stopped, in step S40 the control unit 40 reduces the energization rate to the heating unit 36 ​​to 10% and continues to energize it.

[0068] In step S41, the control unit 40 determines, based on the detection signal from the timer 41, whether or not 70 minutes have elapsed since the start of water supply to the ice tray 32 in step S32. If the control unit 40 determines that 70 minutes have elapsed since the start of water supply in step S41 (YES), the process proceeds to step S42, where the control unit 40 determines whether or not the compressor 23 is operating.

[0069] In step S42, if the control unit 40 determines that the compressor 23 is operating, in step S43, the control unit 40 increases the energization rate to the heating unit 36 ​​to 50% and continues to supply power. On the other hand, in step S42, if the control unit 40 determines that the compressor 23 is stopped, in step S44, the control unit 40 increases the energization rate to the heating unit 36 ​​to 40% and continues to supply power.

[0070] In step S45, the control unit 40 determines, based on the detection signal from the timer 41, whether or not the set time has elapsed since the start of ice making in step S33. If the control unit 40 determines that the set time has elapsed since the start of ice making in step S45 (YES), it returns to step S30. If the control unit 40 determines that the set time has not elapsed since the start of ice making in step S45 (NO), it returns to step S42.

[0071] Here, if the control unit 40 determines in step S30 that the ice in the ice storage container 33 is full, it proceeds to step S46 to determine whether or not the compressor 23 is operating. If the control unit 40 determines in step S46 that the compressor 23 is operating, in step S47 the control unit 40 increases the power supply rate to the heating unit 36 ​​to 50% and continues to supply power.

[0072] On the other hand, in step S46, if the control unit 40 determines that the compressor 23 has stopped, in step S49, the control unit 40 increases the energization rate to the heating unit 36 ​​to 40% and continues to supply power.

[0073] Subsequently, in step S48, the control unit 40 determines, based on the detection signal from the timer 41, whether a predetermined set time, for example, 1 hour, has elapsed since the detection of full ice in the ice storage container 33 in step S30. If the control unit 40 determines that the predetermined set time has elapsed since the detection of full ice in step S48 (YES), it returns to step S30. If the control unit 40 determines that the predetermined set time has not elapsed since the detection of full ice in step S48 (NO), it returns to step S46.

[0074] Furthermore, if the control unit 40 determines in step S41 that 70 minutes have not elapsed since the start of water supply, the process returns to step S33.

[0075] Next, the method for controlling the power supply rate C of the refrigerator 10 will be explained using Figure 5. As shown in the figure, the method for controlling the power supply rate C is when the water supply tank 31 is not empty and the operating status of the refrigerator 10 meets the above condition 2. Steps S50 to S62 in Figure 5 correspond to the control method for the power supply rate C.

[0076] In step S50, the control unit 40 determines, based on the detection signal from the infrared sensor 44, that the first water supply operation to the ice tray 32 has not been performed. Next, in step S51, the control unit 40 determines, based on the detection signal from the door opening / closing sensor 43, whether or not the insulated door 18 of the refrigerator compartment 12 has been opened.

[0077] In step S51, if the control unit 40 determines that the insulated door 18 of the refrigerator compartment 12 is not open without receiving the above detection signal, then in step S52, the control unit 40 determines whether or not the compressor 23 is operating.

[0078] In step S52, if the control unit 40 determines that the compressor 23 is operating, in step S53, the control unit 40 energizes the heating unit 36 ​​at a rate of 30%. On the other hand, in step S52, if the control unit 40 determines that the compressor 23 is stopped, in step S54, the control unit 40 energizes the heating unit 36 ​​at a rate of 25%.

[0079] In step S55, the control unit 40 determines, based on the detection signal from the timer 41, whether or not 70 minutes have elapsed since the last time water was supplied to the ice tray 32. If the result of step S55 is YES, and the control unit 40 determines that 70 minutes have elapsed since the last time water was supplied to the ice tray 32, the process proceeds to step S56, where the control unit 40 increases the power supply rate to the heating unit 36 ​​to 100% and continues to supply power.

[0080] In step S57, the control unit 40 determines, based on the detection signal from the timer 41, whether or not 85 minutes have elapsed since the last time water was supplied to the ice tray 32. If the result of step S57 is YES, and the control unit 40 determines that 85 minutes have elapsed since the last time water was supplied to the ice tray 32, the process proceeds to step S58, where the control unit 40 reduces the power supply rate to the heating unit 36 ​​to 50% and continues to supply power.

[0081] In step S59, the control unit 40 determines, based on the detection signal from the timer 41, whether or not the set time (120 minutes for one cycle) has elapsed since the previous start of water supply to the ice tray 32. If the result of step S59 is YES, and the control unit 40 determines that the set time has elapsed since the previous start of water supply to the ice tray 32, the process proceeds to step S60, where the control unit 40 performs ice inspection in the ice storage container 33 and de-iceing from the ice tray 32 via the ice maker 37, and then supplies water to the ice tray 32.

[0082] On the other hand, if, in step S59, the control unit 40 determines that the set time has not elapsed since the previous start of water supply to the ice tray 32, or if, in step S55, the control unit 40 determines that 70 minutes have not elapsed since the previous start of water supply to the ice tray 32, or if, in step S57, the control unit 40 determines that 85 minutes have not elapsed since the previous start of water supply to the ice tray 32, the process returns to step S51.

[0083] In step S61, the control unit 40 determines from the detection signal from the infrared sensor 44 whether or not the second water supply operation to the ice tray 32 has been performed. If, in step S61, the control unit 40 determines that the second water supply operation to the ice tray 32 has not been performed, the process proceeds to step S10, and the control unit 40 begins controlling the power supply rate A.

[0084] In step S61, if the control unit 40 determines that water has been supplied to the ice tray 32, the process proceeds to step S33, and the control unit 40 starts the ice-making process by controlling the power supply rate B.

[0085] Furthermore, if the control unit 40 determines in step S51 (YES) that the insulated door 18 of the refrigerator compartment 12 has opened, the process proceeds to step S62, where the control unit 40 determines, based on the detection signal from the door opening / closing sensor 43, whether or not the insulated door 18 of the refrigerator compartment 12 has closed. If the control unit 40 determines in step S62 (YES) that the insulated door 18 of the refrigerator compartment 12 has closed, the process proceeds to step S33, where the control unit 40 begins the ice-making process by controlling the power supply rate B. In step S62 (NO), the control unit 40 continues to determine whether the insulated door 18 has closed.

[0086] As described above, in the refrigerator 10 of this embodiment, in the control method for the power supply rate A, if the control unit 40 determines that the above condition 3 is met after detecting the empty state of the water supply tank 31 twice in a row, the control unit 40 determines that, despite heating the water supply pipe 35, water supply to the ice tray 32 has not been performed twice in a row, and that there is no water in the water supply tank 31, in other words, it is empty. In this case, ice making will not be performed until the user supplies water to the water supply tank 31, so power to the heating unit 36 ​​is stopped, and the power consumption of the refrigerator 10 is reduced.

[0087] Furthermore, in the control method for the power supply rate D, if it is detected that the insulated door 18 of the refrigerator compartment 12 has opened or closed, it is possible that the user has supplied water to the water supply tank 31. Therefore, power is supplied to the heating unit 36 ​​at a high power supply rate for a short period of time to prevent the water supply pipe 35 from freezing, thereby preventing blockage due to the water in the water supply pipe 35 freezing during water supply operations.

[0088] Furthermore, in the power supply rate B control method, the power supply rate to the heating unit 36 ​​is reduced to a level that prevents the water in the water supply pipe 35 from freezing until 70 minutes have elapsed since the water supply operation to the ice tray 32. After 70 minutes have elapsed since the water supply operation to the ice tray 32, the power supply rate to the heating unit 36 ​​is increased again. This control method prevents blockage due to freezing of water remaining in the water supply pipe 35 by ensuring that power is continuously supplied to the heating unit 36. Moreover, by temporarily reducing the power supply rate to the heating unit 36, the water supply pipe 35 does not maintain a high temperature, preventing bacteria from growing in the water remaining in the water supply pipe 35, and thus reducing the power consumption of the refrigerator 10.

[0089] Furthermore, in the method for controlling the power supply rate C, after the first empty detection of the water supply tank 31, the power supply rate of the heating unit 36 ​​is first set to the maximum, and then reduced 15 minutes later. In the manufacturing process of the refrigerator 10, there is a possibility of blockage due to freezing of water in the water supply pipe 35 due to various factors, such as the assembly position of the water supply pipe 35 and the heating unit 36, variations in the length of the water supply pipe 35 and variations in the assembly of each component of the refrigerator 10, and the amount of water remaining in the water supply pipe 35 during ice making operation.

[0090] With the above control method, even if the water in the water supply pipe 35 freezes, the frozen state can be thawed by maximizing the power supply rate of the heating unit 36. Furthermore, although the water supply tank 31 is filled with water, the phenomenon of water being unable to be supplied to the ice tray 32 due to the water supply pipe 35 becoming blocked by freezing is prevented. On the other hand, the control unit 40 can determine that the water supply tank 31 is empty, rather than being blocked by freezing in the water supply pipe 35. In addition, by preventing the power supply rate of the heating unit 36 ​​from being maximized for a long period of time, the growth of the above-mentioned bacteria is prevented, and the power consumption of the refrigerator 10 is reduced.

[0091] Finally, as shown in Figures 2(A) and (B), in the water supply operation to the ice tray 32 of this embodiment, the control unit 40 operates the motor 45 in the reverse direction, then in the forward direction, and finally in the reverse direction, so that the water supply pump 34 draws water from the water supply tank 31 and then supplies the drawn water to the ice tray 32 via the water supply pipe 35.

[0092] This control method ensures that even if water melted by heating in the heating unit 36 ​​remains near the tip of the water supply pipe 35 due to surface tension before the water supply operation, the motor 45 is first operated in the reverse direction to draw up the water near the tip of the water supply pipe 35 and allow air to flow through the water supply pipe 35. Then, when the motor 45 is operated in the forward direction, the air inside the water supply pipe 35 is compressed, preventing the water at the tip from suddenly splashing onto the ice tray 32. Finally, the motor 45 is operated in the reverse direction to prevent the siphon effect from occurring.

[0093] In this embodiment, the bottom surface temperature of the ice tray 32 is detected by the infrared sensor 44, and the control unit 40 determines the presence or absence of water in the water tank 31 based on the detection signal. However, the invention is not limited to this case. For example, the current waveform of the water pump 34 may be detected, converted to a voltage value via a resistor, and compared with a preset threshold value. The control unit 40 may then detect whether or not water has been discharged from the water pump 34 based on the comparison result, and determine the presence or absence of water in the water tank 31 based on the detection signal. Various other modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0094] 10 Refrigerator 11 Insulated box 12 Refrigerator 13 Freezer 23 Compressor 25 Blower 27 Insulated partition wall 30 Ice makers 31 Water tank 32 ice cube trays 33 Ice storage container 34 Water supply pump 35 Water supply pipe 36 Heating section 40 Control Unit 42 Internal temperature sensor 43 Door Open / Close Sensor 44 Infrared Sensor

Claims

1. A water supply tank installed in a first storage room for storing water, An ice tray for making ice from the water is provided in the second storage chamber located below the first storage chamber, An ice maker for removing ice made in the aforementioned ice tray, A water supply pump for drawing water from the water supply tank, A water supply pipe that sends the water drawn up by the water supply pump to the ice tray, A heating unit for heating the water supply pipe, The system includes a control unit for controlling the water supply pump, The control unit, in the operation of supplying water from the water tank to the ice tray, first operates the motor that drives the water pump in the reverse direction to allow air to flow through the water pipe, then operates the motor in the forward direction to supply the water from the water tank to the ice tray, and then operates the motor again in the reverse direction to stop the supply of water to the ice tray.

2. The heating unit remains in the water supply pipe and melts the frozen water, The refrigerator according to claim 1, characterized in that the control unit first operates the motor in the reverse direction to suck up the dissolved water remaining at the tip of the pipe due to surface tension.

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