JP2021110484A - Ice making machine - Google Patents

Abstract

To provide an ice making machine which enables increase and decrease of an amount of water circulating between a tank and an ice making part.SOLUTION: An ice making machine includes: an ice making part 11 which freezes water to produce ice; a cooling device 40 which cools the ice making part 11; a tank 13 which stores water; a pump 15 including a pump motor 33 which can change a rotation speed and which can supply the water in the tank 13 to the ice making part 11 in conjunction with driving of the pump motor 33; and a control part 80. The tank 13 is configured to retain water, which is not frozen, of the water supplied to the ice making part 11. The control part 80 operates the cooling device 40 and the pump motor 33 to perform ice making operation, in which ice is produced in the ice making part 11, and controls the rotation speed of the pump motor 33 in the ice making operation.SELECTED DRAWING: Figure 1

Description

The present invention relates to an ice machine.

Conventionally, as an ice maker, for example, the one described in Patent Document 1 is known. Patent Document 1 describes a configuration in which water stored in a tank (ice making water tank) is supplied to an ice making section (ice making plate) by a pump (circulation pump). In Patent Document 1, the water that has not been frozen in the ice making section is returned to the tank. Therefore, the pump makes it possible to circulate water (ice making water) between the tank and the ice making section.

Japanese Patent No. 5448618

By the way, as a pump motor provided in a pump for circulating water between a tank and an ice making section, an AC motor having a constant rotation speed is generally used. If the rotation speed of the pump motor is constant, there is a problem that the amount of water circulating between the tank and the ice making section cannot be changed. For example, when an ice making operation for producing ice is performed in an ice making section, if the amount of water circulating is large, the ice making water is likely to be supercooled, and there is a concern that cotton ice may be generated. However, if the amount of water circulation is reduced so that cotton ice is not generated, it takes time to cool the ice-making water at the initial stage of the ice-making operation, and the ice-making efficiency is lowered. Under these circumstances, there is a demand for an ice maker capable of increasing or decreasing the amount of water circulating between the tank and the ice making section during the ice making operation.

The present invention has been completed based on the above circumstances, and an object of the present invention is to provide an ice maker capable of increasing or decreasing the amount of water circulating between the tank and the ice making section.

As a means for solving the above problems, the ice machine disclosed in the present specification includes an ice making section that produces ice by freezing water, a cooling device that cools the ice making section, and a tank that stores water. A pump including a pump motor capable of changing the rotation speed, and a pump capable of supplying water in the tank to the ice making unit as the pump motor is driven, and a control unit. The tank is configured such that, of the water supplied to the ice making unit, unfrozen water is stored in the tank, and the control unit operates the cooling device and the pump motor. It is assumed that the ice-making unit executes an ice-making operation for producing ice, and the ice-making operation is characterized in that the rotation speed of the pump motor is controlled.

In the above configuration, water (ice making water) can be circulated between the tank and the ice making section by driving the pump motor. Further, by increasing or decreasing the rotation speed of the pump motor, the amount of ice-making water circulating between the tank and the ice-making part can be increased or decreased. In the initial stage of the ice making operation, it is preferable to efficiently cool the ice making water in the ice making section by operating the pump motor at a relatively high rotation speed and increasing the circulation amount of the ice making water. However, if the ice-making water is sufficiently cooled and the circulation amount of the ice-making water continues to be large, there is a concern that the supercooling of the ice-making water causes cotton ice to be generated in the tank, which hinders the circulation of the ice-making water. In the above configuration, since the control unit can reduce the rotation speed of the pump motor during the ice making operation, the circulation amount of ice making water between the tank and the ice making part can be reduced at a predetermined timing, and the cotton ice can be reduced. Can be suppressed.

Further, the ice making section temperature sensor capable of detecting the temperature of the ice making section is provided, and the control unit has a predetermined temperature or less in which the temperature detected by the ice making section temperature sensor is higher than 0 ° C. during the ice making operation. In the case of

In the ice making operation, the ice making water is cooled, and the temperature of the ice making section is lowered accordingly. If the rotation speed of the pump motor is reduced while the temperature of the ice making section is below the specified temperature (higher than 0 ° C) (the ice making water is sufficiently cold), the flow rate of the ice making water in the ice making section decreases. As the temperature of the ice making section is further lowered, seed ice is likely to occur in the ice making section. When seed ice is generated, the ice grows around the seed ice as a core. If there is ice in the ice making section, the heat exchange efficiency in the ice making section is lowered, so that the ice making water is hard to be cooled and supercooling is hard to occur. Therefore, by lowering the rotation speed of the pump motor and increasing the rotation speed of the pump motor after seed ice is formed after a lapse of a predetermined time, ice production can be performed while suppressing the generation of cotton ice. It can be done faster.

Further, the control unit includes a water temperature sensor capable of detecting the temperature of the water stored in the tank, and the control unit has a temperature detected by the water temperature sensor higher than 0 ° C. or lower during the ice making operation. In the case of

In the ice making operation, since the ice making water that has passed through the ice making section is stored in the tank, the water temperature of the tank follows the temperature of the ice making water in the ice making section. If the rotation speed of the pump motor is reduced while the water temperature in the tank is below the specified temperature (higher than 0 ° C) (the ice making water is sufficiently cold), the flow rate of the ice making water in the ice making section decreases, and ice making occurs. As the temperature of the part is further lowered, seed ice is likely to be generated in the ice making part. When seed ice is generated, the ice grows around the seed ice as a core. If there is ice in the ice making section, the heat exchange efficiency in the ice making section is lowered, so that the ice making water is hard to be cooled and supercooling is hard to occur. Therefore, by lowering the rotation speed of the pump motor and increasing the rotation speed of the pump motor after seed ice is formed after a lapse of a predetermined time, ice production can be performed while suppressing the generation of cotton ice. It can be done faster.

Further, the pump motor is a DC motor, and the control unit normally circulates water between the tank and the ice making unit when the rotation speed of the pump motor becomes equal to or lower than a predetermined rotation speed. It can be determined that this has not been done. If scale is deposited in the water circulation path between the tank and the ice making section, the water circulation is hindered and the load acting on the pump motor is increased, so that the rotation speed of the pump motor is reduced. Therefore, when the rotation speed becomes equal to or less than a predetermined rotation speed, the control unit can determine that the water circulation between the tank and the ice making unit is not normally performed.

Further, the pump motor is a DC motor, and the control unit normally circulates water between the tank and the ice making unit when the current value of the pump motor becomes a predetermined current value or more. It can be determined that this has not been done. If scale is deposited in the water circulation path between the tank and the ice making section, the water circulation is hindered and the load acting on the pump motor is increased, so that the current of the pump motor is increased. Therefore, when the current value of the pump motor becomes equal to or higher than a predetermined current value, the control unit can determine that the water circulation between the tank and the ice making unit is not normally performed.

Further, a water level sensor capable of measuring the water level of the water stored in the tank is provided, the ice making section is provided with an ice making plate having an ice making surface on which water flows down, and the tank is below the ice making plate. The control unit may perform a process of gradually lowering the rotation speed of the pump motor as the water level measured by the water level sensor becomes lower during the ice making operation. ..

In the above configuration, the water level in the tank becomes lower as the ice on the ice making surface grows (becomes larger). Further, in the process of water flowing down the ice making surface, the water may be repelled by the ice on the ice making surface and scattered, and the larger the ice, the larger the amount of water scattered. Therefore, as the water level becomes lower, the rotation speed of the pump motor is gradually lowered, so that the amount of water scattered can be reduced and the water can be returned to the tank more reliably. Further, by lowering the rotation speed of the pump motor, the amount of water in the circulation path between the tank and the ice plate can be reduced. Since the water in the circulation path is not used for ice making, it is possible to save water by reducing the amount of such water.

Further, the control unit is supposed to execute a cleaning operation of circulating water between the tank and the ice making unit by operating the pump motor with the cooling device stopped, and during the cleaning operation. In addition, the process of lowering the rotation speed of the pump motor and the process of increasing the rotation speed of the pump motor can be alternately repeated. In the washing operation, the water circulation path can be washed by circulating water between the tank and the ice making section. Then, in the washing operation, by repeating increasing and decreasing the rotation speed of the pump motor, water can be pulsated in the circulation path, and the water circulation path can be washed more efficiently.

Further, a pipe connecting the ice making section and the pump, a drain pipe drawn from the intermediate portion of the pipe to drain the water in the tank to the outside, and a drain valve for opening and closing the drain pipe. The ice-making unit is arranged at a position higher than that of the pump, and the control unit operates the pump motor with the drain valve open to allow the inside of the tank to pass through the drain pipe. A drainage operation for draining water to the outside is performed, and in the drainage operation, the height of the water pumped by the pump is set to a height between the ice making part and the intermediate part of the pump motor. The rotation speed can be controlled.

By operating the pump, it is possible to drain the water in the tank in addition to supplying water to the ice making section. And since the height (lift) of the water pumped by the pump in the drainage operation is set to be the height between the ice making part and the middle part, it is possible to suppress the situation where the water in the tank goes to the ice making part. , Can be reliably drained.

Further, a water supply pipe for supplying water from an external water source to the tank, a water supply valve for opening and closing the water supply pipe, a pipe connecting the ice making part and the pump, and an intermediate part of the pipe are drawn out. A drain pipe for draining the water in the tank to the outside and a drain valve for opening and closing the drain pipe are provided, and the control unit opens the water supply valve to provide the tank with the external water source. Water is circulated between the tank and the ice making section by operating the pump motor with the cooling device stopped, which is executed after the first treatment for supplying water from the water and the first treatment. The second treatment and the third treatment, which is executed after the second treatment and operates the pump motor with the drain valve open, drains the water in the tank to the outside through the drain pipe. , Can be executed on a regular basis.

When the ice making operation is executed, the water circulating between the tank and the ice making section becomes cold. On the other hand, if the ice making operation is not executed for a long time, the water temperature of the water remaining in the water circulation path between the tank and the ice making section (hereinafter, simply referred to as the circulation path) rises, and bacteria grow. It is possible that it will be easier to breed. By executing the first treatment to the third treatment, the water remaining in the circulation path can be washed with the supplied water and drained. By periodically executing such first to third processes, it is possible to maintain the inside of the circulation path in a cleaner state even when the state in which the ice making operation is not executed continues for a long time.

Further, the control unit may execute the first process, the second process, and the third process when the power supply of the ice machine is switched from the off state to the on state. If the power of the ice maker remains off for a long time when water remains in the circulation path, the temperature of the water remaining in the circulation path rises, and it is conceivable that bacteria can easily grow. Therefore, when the power is switched to the on state, the first process to the third process are periodically executed in this order to make the inside of the circulation path clean before executing the ice making operation. can.

Further, a UV sterilizer for sterilizing the water in the tank by irradiating the water in the tank with ultraviolet rays is provided, and the control unit operates the UV sterilizer after executing the third treatment. Therefore, the fourth treatment for sterilizing the water in the tank can be executed. The water in the tank that could not be completely drained by the third treatment can be sterilized by the UV sterilizer. As a result, the inside of the tank can be made cleaner.

According to the present invention, it is possible to provide an ice maker capable of increasing or decreasing the amount of water circulating between the tank and the ice making section.

Diagram showing an ice machine Perspective view showing the ice making part A cross-sectional view showing an enlarged view of the vicinity of the storage pipe in the tank. Block diagram showing the electrical configuration of the ice machine Flow chart showing the processing of the control unit related to the ice making operation Flow chart showing the processing of the control unit related to the deicing operation Flow chart showing the processing of the control unit related to the cleaning operation The figure which shows the ice machine of the comparative example Flow chart showing the processing of the control unit related to the residual water treatment operation Timing chart showing the timing when the residual water treatment operation is executed Flow chart showing the processing of the control unit when the power is turned on

An embodiment of the present invention will be described with reference to FIGS. 1 to 11. In the present embodiment, as the ice maker, a flow-down type ice maker 10 is illustrated. As shown in FIG. 1, the ice maker 10 cools a plurality of ice making units 11 that produce ice by freezing water, and ice making units 11 (more specifically, each ice making plate 12 included in the ice making unit 11). The device 40, a tank 13 capable of storing water supplied to the ice making unit 11, an ice storage tank 14 (ice storage unit) capable of storing ice produced in the ice making unit 11, and a tank in the ice making unit 11. A pump 15 capable of supplying the water in the 13 is provided.

Further, the ice machine 10 can detect the temperature of the ice making section 11 (more specifically, the ice making plate 12) and the ice making section temperature sensor 16 and the temperature of the water stored in the tank 13. A drain pipe 20 for connecting the water temperature sensor 17, the ice making section 11 and the pump 15, a drain pipe 20 drawn from the intermediate portion 19 of the pipe 18 and draining the water in the tank 13 to the outside, and a drain pipe 20 are provided. A drain valve 21 that opens and closes, a distance sensor 22 that is arranged above the water stored in the tank 13 and can measure the distance of the water stored in the tank 13 to the water surface 58, and an ice storage tank 14. Ice storage section side distance sensor 23 (ice storage tank side distance) that is placed above the ice and can measure the distance to the upper surface 14D (see the two-point chain line in FIG. 1) of the ice stored in the ice storage tank 14. Sensor) and.

The ice making section 11 includes a plurality of ice making plates 12, a watering pipe 24, and a watering guide 25. The ice plate 12 is provided in a vertical position. In the plurality of ice making plates 12, a meandering evaporation pipe 44 (a part of the cooling device 40) is provided between the pair of ice making plates 12 and 12 arranged to face each other. As shown in FIG. 2, the ice making plate 12 has a plurality of ice making surfaces 12A extending in the vertical direction and a plurality of ridge portions 12B extending in the vertical direction. The plurality of ice making surfaces 12A are arranged along the horizontal direction, and the adjacent ice making surfaces 12A are separated by the ridge portion 12B. The ice making surface 12A is formed by a surface of the ice making plate 12 opposite to the evaporation pipe 44. A watering pipe 24 (watering nozzle) is provided for each pair of ice making plates 12, 12. The ice-making water sent from the pump 15 to the watering pipe 24 is sprinkled on each ice-making surface 12A by the watering pipe 24. The ice-making water sprinkled from the watering pipe 24 is guided to each ice-making surface 12A by the watering guide 25, and then flows down each ice-making surface 12A.

As shown in FIG. 1, the cooling device 40 includes a compressor 41, a condenser 42, an expansion valve 43, an evaporation pipe 44, and a fan 46. The compressor 41, the condenser 42, the expansion valve 43, and the evaporation pipe 44 are connected by a refrigerant pipe 45 filled with a refrigerant. The compressor 41 compresses the refrigerant gas. The condenser 42 cools the compressed refrigerant gas by blowing air from the fan 46 to liquefy it. The expansion valve 43 expands the liquefied refrigerant. The evaporation pipe 44 (evaporator) vaporizes the liquefied refrigerant expanded by the expansion valve 43 to cool the ice plate 12. As described above, the compressor 41, the condenser 42, the expansion valve 43, the evaporation pipe 44, and the refrigerant pipe 45 form a refrigerant circulation cycle (refrigerant circuit) for cooling the ice plate 12. Further, the cooling device 40 includes a dryer 47 for removing the water mixed in the refrigerating circuit. The ice making section temperature sensor 16 is provided in the refrigerant pipe 45 near the outlet of the evaporation pipe 44, and can detect the temperature of the ice making plate 12. As the ice making section temperature sensor 16, for example, a thermistor can be used, but the present invention is not limited to this.

Further, the cooling device 40 includes a bypass pipe 49 for supplying the refrigerant gas (hot gas) compressed by the compressor 41 to the evaporation pipe 44, and a hot gas valve 50 which is an electromagnetic valve provided in the bypass pipe 49. , Equipped with. By opening the hot gas valve 50, it is possible to supply the refrigerant gas (hot gas) from the compressor 41 to the evaporation pipe 44 and heat the evaporation pipe 44. That is, the cooling device 40 has a function as a heating device for heating the evaporation pipe 44.

As shown in FIGS. 1 and 3, the tank 13 includes a box-shaped tank body 26 that is opened upward, and a lid 27 that covers the opening of the tank body 26. Ice-making water used for ice-making is stored in the internal space of the tank main body 26. The tank main body 26 is arranged below the ice making section 11. The lid 27 is not provided in the tank main body 26 at a position directly below the ice making section 11. Further, a drainboard 28 is interposed between the tank main body 26 and the ice making 11. As a result, the water flowing down from the ice making section 11 passes through the drainboard 28 and is stored in the tank 13.

Further, a water supply pipe 52 (watering pipe on the water supply side) is provided between the pair of ice making plates 12 and 12. Further, the ice machine 10 includes a water supply pipe 29 for supplying water from a water pipe 31 (external water source) to the tank 13, and a water supply valve 30 for opening and closing the water supply pipe 29. The water supply pipe 52 is connected to the water pipe 31 via the water supply pipe 29 and the water supply valve 30. As a result, by opening the water supply valve 30, tap water flows down the back surface of the ice making plate 12 (the surface opposite to the ice making surface 12A) and then is supplied to the tank 13. Further, among the ice-making water flowing down the ice-making surface 12A, the water that has not been frozen is stored in the tank 13. That is, the tank 13 has a configuration in which, of the ice-making water supplied to the ice-making unit 11, unfrozen water is stored in the tank 13. As a result, by operating the pump 15, ice-making water can be circulated between the tank 13 and the ice-making unit 11. In the present specification, the ice-making water is not limited to the water used for ice-making, but includes water circulating between the tank 13 and the ice-making section 11.

Further, the tank 13 can drain the water exceeding the overflow water level L1 to the outside of the tank 13 when the water in the tank 13 exceeds a predetermined overflow water level L1 (see the two-dot chain line in FIG. 3). It is said that it has a similar structure. More specifically, in the tank main body 26, an overflow space A2 is provided adjacent to the water storage space A1 in which water is stored. The overflow space A2 has a function of draining the overflowing water from the water storage space A1. The tank main body 26 has a vertical wall portion 32 that separates the overflow space A2 and the water storage space A1, and the upper end of the vertical wall portion 32 is arranged at a position lower than the upper end of the side wall portion of the tank main body 26. The height of the upper end of the vertical wall portion 32 coincides with the overflow water level L1 of the tank 13. As a result, when the water level of the water storage space A1 exceeds the height of the upper end of the standing wall portion 32, the water exceeds the upper end of the standing wall portion 32 and flows into the overflow space A2 to be drained. The overflow space A2 may be configured by an overflow pipe provided in the tank 13.

The pump 15 includes a pump motor 33 capable of changing the rotation speed, and can supply water in the tank 13 to the ice making section 11 as the pump motor 33 is driven. The pump motor 33 is a DC motor (DC brushless motor) capable of changing the rotation speed. As a result, by increasing or decreasing the rotation speed of the pump motor 33, it is possible to increase or decrease the amount of water supplied to the ice making section 11 (and thus the amount of water circulating between the tank 13 and the ice making section 11). There is.

Further, the ice making section 11 is arranged at a position higher than the pump 15, and the pipe 18 extends upward from the pump 15. A drain pipe 20 for draining the water in the tank 13 to the outside is provided in the intermediate portion 19 of the pipe 18, and a drain valve 21 for opening and closing the drain pipe 20 is provided in the drain pipe 20. .. As a result, when the pump 15 is operated with the drain valve 21 open, the water in the tank 13 can be drained through the drain pipe 20.
When the pump 15 is operated with clean water or detergent in the tank 13, the ice making surface 12A side of the ice making section 11 can be washed. Further, the water supply pipe 29 and the pipe 18 are connected via a part of the drainage pipe 20 and a valve 34. As a result, when the valve 34 is opened and the pump 15 is operated with the water supply valve 30 and the drain valve 21 closed, the water in the tank 13 can be supplied to the back surface of the ice plate 12 through the water supply pipe 52, and the back surface of the ice plate 12 can be supplied. Can be washed.

The distance sensor 22 is arranged above the water stored in the tank 13 and measures the distance to the water surface of the water stored in the tank 13 by irradiating ultrasonic waves toward the water surface of the water in the tank 13. It is an ultrasonic sensor that can be used. More specifically, the distance sensor 22 includes an irradiation unit that irradiates ultrasonic waves and a reception unit that receives ultrasonic waves reflected by the water surface of the water in the tank 13, and the ultrasonic waves emitted from the irradiation unit are reflected by reflection. It is possible to measure the distance from the distance sensor 22 to the water surface based on the time until it returns to the receiving unit. Since the distance from the distance sensor 22 to the water surface is linked to the water level of the tank 13, the distance sensor 22 can be used as a water level sensor capable of measuring the water level of the water stored in the tank 13. By using the distance sensor 22 as a water level sensor, the water level can be detected linearly.

As shown in FIG. 3, the distance sensor 22 is housed in a storage pipe 35 provided in a lid 27 that covers the tank 13. By accommodating the distance sensor 22 in the accommodating pipe 35, it is possible to reduce the measurement error of the distance sensor 22 due to the change in the ambient temperature. The accommodation pipe 35 is a circular pipe that is long in the vertical direction, and is arranged so as to penetrate the lid 27. Further, the accommodating pipe 35 is opened downward, and its lower end (opening end) is arranged so as to face the bottom surface 13A of the tank 13 with a slight gap. Therefore, in the tank 13, the water level in the accommodating pipe 35 is the same as the water level in the water outside the accommodating pipe 35. Further, a notch 36 is formed at the open end (lower end) of the accommodating pipe 35. By providing such a notch 36, it is possible to suppress a situation in which water undulates in the accommodating pipe 35, and it is possible to further improve the measurement accuracy of the water level.

Further, at a position higher than the lid 27 in the accommodating pipe 35, an air hole 37 that communicates the inside and the outside (outside of the tank 13) of the accommodating pipe 35 is formed. The air holes 37 are arranged at a position higher than the lid 27. When the water level in the accommodating pipe 35 rises, the air in the accommodating pipe 35 is discharged to the outside through the air hole 37 by the amount of the increase in the water level.

The distance sensor 22 is provided on the ceiling portion 35A of the accommodation pipe 35. That is, the distance sensor 22 is arranged at a position higher than the lid 27. Therefore, it is possible to prevent the water in the tank 13 from adhering to the distance sensor 22. The directivity angle of the ultrasonic waves emitted from the distance sensor 22 is set so that the irradiation range H1 of the ultrasonic waves irradiated to the bottom surface 13A of the tank 13 is substantially equal to the cross-sectional area of the accommodating pipe 35. As a result, it is possible to suppress a situation in which the ultrasonic waves emitted from the distance sensor 22 are reflected on the inner surface of the accommodating pipe 35. The directivity angle of the ultrasonic wave emitted from the distance sensor 22 is set within the range of, for example, 5 degrees to 10 degrees, but is not limited to this.

Further, in the accommodating pipe 35, a first sound absorbing material 38 is provided so as to surround the distance sensor 22 from the entire circumference in the horizontal direction, and a second sound absorbing material 39 is provided so as to surround the first sound absorbing material 38. There is. The first sound absorbing material 38 and the second sound absorbing material 39 are made of different materials. For example, the first sound absorbing material 38 is made of a rubber material, and the second sound absorbing material 39 is made of a foaming material. By surrounding the distance sensor 22 with the first sound absorbing material 38 and the second sound absorbing material 39, it is possible to suppress the situation where the distance sensor 22 receives external noise, and the measurement accuracy of the distance sensor 22 can be further improved. Can be done.

Further, a water temperature sensor 17 (see FIG. 1) capable of detecting the temperature of the water stored in the tank 13 is provided between the pump 15 and the distance sensor 22. The water temperature sensor 17 is attached to the lid 27 and is provided so as to come into contact with the water in the tank 13. As the water temperature sensor 17, for example, a thermistor can be used, but the water temperature sensor 17 is not limited to this.

The ice storage tank 14 stores the ice produced by the ice making unit 11, and as shown in FIG. 1, is arranged below the ice making unit 11 and communicates with the ice making unit 11 via the ice discharge pipe 51. There is. The user takes out the ice made from the ice storage tank 14 and uses it. The slatted board 28 described above constitutes a part of the ice discharge pipe 51. The slatted board 28 is provided in a posture of descending and tilting toward the ice inlet 14A in the ice storage tank 14. As a result, the ice that has fallen on the drainboard 28 is sent toward the entrance 14A. The ice storage unit side distance sensor 23 is an ultrasonic sensor provided on the upper wall portion 14B constituting the ice storage tank 14, and by irradiating the upper surface 14D of the ice stored in the ice storage tank 14 with ultrasonic waves, the ice is iced. It is configured so that the distance to the upper surface 14D of the surface can be measured.

In other words, the ice storage unit side distance sensor 23 can measure the amount of ice stored in the ice storage tank 14. Specifically, as the amount of ice in the ice storage tank 14 increases, the upper surface of the ice rises, so that the distance from the ice storage unit side distance sensor 23 to the upper surface of the ice decreases, and the amount of ice in the ice storage tank 14 decreases. Then, since the upper surface of the ice is lowered, the distance from the ice storage portion side distance sensor 23 to the upper surface of the ice is increased.

Next, the electrical configuration of the ice machine 10 will be described. As shown in FIG. 4, the ice maker 10 includes a control unit 80. The control unit 80 includes a cooling device 40 (more specifically, a compressor 41, a fan 46, a hot gas valve 50), a distance sensor 22, an ice storage unit side distance sensor 23, a pump motor 33, an ice making unit temperature sensor 16, and a water temperature. The sensor 17, the water supply valve 30, the drain valve 21, the valve 34, the timing unit 53 (timer), the storage unit 54, and the UV sterilizer 70 are electrically connected. Further, the ice machine 10 includes an operation unit 55 including a switch that can be operated by the user, and a display unit 56 (for example, a liquid crystal panel) that can display an error message or the like. That is, the display unit 56 is a notification unit capable of notifying the operator of an error. The operation unit 55 and the display unit 56 are electrically connected to the control unit 80, respectively.

The control unit 80 is mainly composed of, for example, a CPU, and the storage unit 54 is composed of, for example, a ROM or RAM. By executing the program stored in the storage unit 54, the control unit 80 operates the operation unit 55 by the user, and each sensor (distance sensor 22, ice storage unit side distance sensor 23, ice making unit temperature sensor 16, water temperature sensor). It is possible to control the operation of each device (cooling device 40, pump motor 33, water supply valve 30, drain valve 21, valve 34, display unit 56) based on the measured value of 17) and the time measured by the time measuring unit 53. It has become. Further, the storage unit 54 stores each set value related to the operation of the ice maker. Further, the control unit 80 can refer to the rotation speed and the current value of the pump motor 33.

The control unit 80 can execute the ice making operation, the deicing operation, and the washing operation, respectively. The ice making operation is an operation of producing ice in the ice making section 11 by operating the pump motor 33 while operating the cooling device 40 to cool the ice making plate 12. The ice removal operation is to remove the produced ice from the ice making surface 12A of the ice making section 11 by operating the pump motor 33 and the water supply valve 30 while operating the cooling device 40 to heat the ice making plate 12. It is driving. The washing operation is an operation in which water is circulated between the tank 13 and the ice making section 11 by operating the pump motor 33 with the cooling device 40 stopped, and the circulation path of the ice making water is washed. Yes (more on this later).

Further, the control unit 80 can control the rotation speed of the pump motor 33. In this embodiment, as the rotation speed of the pump motor 33, five stages of rotation speeds of high speed V1, medium speed V2, low speed V3, high speed V4A during cleaning, and low speed V4B during cleaning are set. It should be noted that V1> V2> V3, V4A> V1, and V4A> V4B, but the value of each rotation speed can be set as appropriate. Further, in the following description, "the control unit 80 opens the water supply valve 30 to supply tap water into the tank 13" may be referred to as "water supply".

Next, the processing of the control unit 80 in the ice making operation will be described. The ice making operation is executed, for example, by the user performing an operation for starting the ice making operation using the operation unit 55. Before the ice making operation is performed, the control unit 80 executes a water supply process for supplying water to the tank 13. In the water supply process, the control unit 80 supplies tap water into the tank 13 by opening the water supply valve 30. The control unit 80 performs water supply processing when the distance to the water surface detected by the distance sensor 22 becomes the preset operation start distance K2, in other words, when the water level in the tank 13 becomes the operation start water level L2. And start the ice making operation.

That is, the operation start water level L2 is the water level on the water surface corresponding to the operation start distance K2. The operation start distance K2 (operation start water level L2) can be appropriately set. The operation start distance K2 is set so that, for example, as shown in FIG. 3, the operation start water level L2 is lower than the overflow water level L1 described above. Further, the operation start water level L2 may be the same height as the overflow water level L1.

In the ice making operation, as shown in FIG. 5, the control unit 80 operates the cooling device 40 (step S1) to cool the ice making plate 12. Further, in the ice making operation, the control unit 80 controls the rotation speed of the pump motor 33 based on the state of ice on the ice making surface 12A. Immediately after the start of the ice making operation, the control unit 80 operates the pump motor 33 at high speed V1 (step S2). When the pump motor 33 is operated, ice-making water circulates between the tank 13 and the ice-making unit 11, and the ice-making water is cooled in the process of flowing down the cooled ice-making surface 12A. Immediately after the start of the ice making operation, the ice making water in the tank 13 has a temperature close to tap water (for example, 20 ° C.), and in order to freeze this, it is necessary to cool the ice making water to 0 ° C. By operating the pump motor 33 at high speed V1 immediately after the start of the ice making operation, the circulation amount of the ice making water between the tank 13 and the ice making section 11 can be increased, so that the ice making water can be cooled efficiently. ..

Further, when the pump motor 33 is operated, the water in the tank 13 is sent to the circulation path of the ice making water other than the tank 13 (the pipe 18 and the ice making section 11 and the like), so that the water level in the tank 13 is lowered. Therefore, the control unit 80 sets the water level in the tank 13 to the operation start water level after a predetermined time T1 (for example, 15 seconds) has elapsed after the pump motor 33 is operated at the high speed V1 (“YES” in step S3). Water is supplied until it reaches L2 (step S4, additional water supply treatment). That is, the tank 13 is replenished with the amount of water reduced from the tank 13 due to the operation of the pump motor 33. Further, the control unit 80 adds a predetermined value K3 (predetermined distance) to the operation start distance K2 when the additional water supply treatment is completed (when the water level in the tank 13 returns to the operation start water level L2). It is stored in the storage unit 54 as the operation stop distance K4. When the value of the distance sensor 22 reaches the operation stop distance K4, the ice making operation is stopped (details will be described later). The operation stop distance K4 may be stored in the storage unit 54 at a time before the start of the ice making operation (for example, when the operation start distance K2 is input).

As shown in FIG. 3, the operation stop distance K4 is a distance from the operation start water level L2 to the water surface at a water level (operation stop water level L4) lower by a predetermined value K3. Further, the predetermined value K3 corresponds to the amount of ice produced in the ice making operation. In the present embodiment, the predetermined value K3 can be set by the user operating the operation unit 55. That is, in the present embodiment, by setting the predetermined value K3, it is possible to set the operation stop water level L4 and, by extension, the amount of ice produced in the ice making operation (the size of each ice 57).

When the temperature of the ice-making water is lowered, the heat exchange between the ice-making water and the ice-making plate 12 is suppressed, so that the temperature of the ice-making plate 12 is lowered. After the water level in the tank 13 reaches the operation start water level L2 (after step S4), the control unit 80 satisfies the following condition FA1 or condition FA2 (“YES” in step S5), the pump motor 33 Is set to low speed V3 (step S6). The following predetermined temperatures C1 and C2 are values larger than 0 ° C. and close to 0 ° C., and can be appropriately set. The predetermined temperature C1 is preferably set in the range of, for example, 1 ° C. to 5 ° C., and the predetermined temperature C2 is preferably set in the range of, for example, 2 ° C. to 10 ° C. In other words, the control unit 80 sets the pump motor to low speed V3 before the temperature of the ice making water reaches 0 ° C. (before ice is generated on the ice making surface 12A).
Condition FA1: Detection temperature of the water temperature sensor 17 that measures the water temperature of the tank 13 ≤ predetermined temperature C1 (for example, 2.5 ° C.)
Condition FA2: Detection temperature of ice making part temperature sensor 16 ≤ predetermined temperature C2 (for example, 5 ° C.)

When the pump motor 33 is changed from the high speed V1 to the low speed V3, the circulation amount of the ice making water is reduced and the amount of the ice making water flowing down the ice making surface 12A is reduced, so that the temperature of the ice making surface 12A is further lowered. As a result, ice nuclei (seed ice) are likely to be formed at a portion of the ice making surface 12A corresponding to the evaporation pipe 44 (a portion of the ice making surface 12A where the temperature is particularly low). Further, by setting the pump motor 33 to the low speed V3, the cooling of the ice making water is suppressed, so that the situation where the ice making water is overcooled can be suppressed, and the situation where cotton ice is generated in the tank 13 can be suppressed.

Next, when the following condition FA3 is satisfied (“YES” in step S7), the control unit 80 sets the pump motor 33 to medium speed V2 (step S8). The following predetermined temperature C3 is a temperature higher than 0 ° C. and lower than the predetermined temperature C2.
Condition FA3: The state of the detection temperature of the ice making section temperature sensor 16 ≤ the predetermined temperature C3 (for example, 1 ° C.) continued for a predetermined time T3 (for example, 120 seconds).
Further, the control unit 80 may set the pump motor 33 to medium speed V2 when it detects that seed ice has occurred on the ice making surface 12A instead of the condition FA3. The seed ice can be detected, for example, by photographing the ice making surface 12A with a camera and analyzing the photographed image.

After the pump motor is set to low speed V3, the temperature of the ice making plate 12 is sufficiently lowered, and then T3 elapses for a predetermined time, so that seed ice is generated on the ice making surface 12A. Therefore, the control unit 80 determines that seed ice has been generated by satisfying the condition FA3, sets the pump motor 33 to medium speed V2, and increases the circulation amount of ice making water. The predetermined time T3 can be set as appropriate, and can be determined, for example, by measuring the time when the seed ice is actually generated by a test or the like.

That is, the control unit 80 performs a process (to a medium speed V2) of increasing the rotation speed of the pump motor 33 after a predetermined time has elapsed after the pump motor 33 is set to a low speed V3. In the state after the seed ice is generated on the ice making surface 12A, the ice making water freezes in the process of flowing down the surface of the seed ice. As a result, as time passes, the crescent-shaped ice 57 (see FIG. 1) protruding from the ice making surface 12A grows. When ice 57 is generated on the ice making surface 12A, the heat exchange between the ice making surface 12A and the ice making water is suppressed by the ice 57, so that the cooling rate of the ice making water decreases. Therefore, after seed ice is generated, cotton ice is unlikely to be generated even if the rotation speed of the pump motor 33 is increased.

Further, as the ice 57 grows on the ice making surface 12A, the water level in the tank 13 decreases. After step S8, the control unit 80 performs a rotation speed reduction process (step S9). In the rotation speed reduction process, the rotation speed of the pump motor 33 is gradually reduced as the distance to the water surface measured by the distance sensor 22 increases (as the water level in the tank 13 measured by the water level sensor decreases). As the ice on the ice making surface 12A becomes larger, the ice making water supplied to the ice making plate 12 is easily scattered by being repelled by the ice. Since the scattered ice-making water does not return to the tank 13, the amount of water used for ice-making is reduced, and the ice becomes smaller than the desired size. Therefore, as the ice grows, the rotation speed of the pump motor 33 is gradually reduced, so that the circulation amount of the ice-making water can be reduced, and the situation where the ice-making water is scattered can be suppressed. In the rotation speed reduction process, the rotation speed of the pump motor 33 may be continuously reduced or may be gradually reduced.

Then, when the water level in the tank 13 reaches the operation stop water level L4 (“YES” in step S10, the control unit 80 stops the operation in which the distance to the water surface detected by the distance sensor 22 is larger than the operation start distance K2. When the distance reaches K4), the pump motor 33 is stopped to stop the ice making operation, and the process shifts to the deicing operation. In addition, instead of step S10, the control unit 80 has continued "a state in which the water level in the tank 13 is the operation stop water level L4 or less" for a predetermined time T9 (for example, 20 seconds) (the water level in the tank 13 has stopped operation). The pump motor 33 may be stopped to stop the ice making operation and shift to the deicing operation on condition that the water level is stable at L4 or less). By doing so, the influence of the water level change due to the waviness of the water surface in the tank 13 can be suppressed, so that the size of the ice that is made can be made the same each time when the ice making operation is repeated.

Further, when the following condition FE1 or condition FE2 is satisfied during the ice making operation, the control unit 80 determines that the water circulation between the tank 13 and the ice making unit 11 is not normally performed, and the display unit 80. An error message for notifying the user that "water circulation is not performed normally (error)" is displayed on 56. In other words, when the following condition FE1 or condition FE2 is satisfied during the ice making operation, the control unit 80 notifies the error as an error handling process corresponding to an error (water circulation is not performed normally). do.
Condition FE1: Rotation speed VX of pump motor 33 ≤ predetermined rotation speed V6
Condition FE2: Current value IX of pump motor 33 ≧ predetermined current value I1

The reason why the water circulation between the tank 13 and the ice making section 11 is not performed normally is considered to be the precipitation of scale in the ice making water circulation path. In the circulation path, scale is particularly likely to precipitate at a place where the flow velocity is slow (the end of the watering pipe 24, the end of the watering guide 25, etc.). Therefore, when the condition FE1 or the condition FE2 is satisfied, the control unit 80 may execute the cleaning operation as an error handling process. Further, when the condition FE1 or the condition FE2 is satisfied, the control unit 80 may stop the operation of the ice maker 10 as an error handling process.

Further, the control unit 80 executes an error notification process for notifying an error when the following condition FE3 or condition FE4 is satisfied for a predetermined time during the ice making operation. In the error notification process, the control unit 80 displays, for example, an error message notifying the user that "the water level of the tank is an abnormal water level" on the display unit 56.
Condition FE3: Distance to the water surface measured by the distance sensor 22 ≥ first abnormal distance K5
Condition FE4: Distance to the water surface measured by the distance sensor 22 ≤ 2nd abnormal distance K6
The control unit 80 may execute an error notification process for notifying an error when the condition FE3 or the condition FE4 is satisfied for a predetermined time during the deicing operation or the washing operation.

The first abnormal distance K5 is a value larger than the operation stop distance K4. The second abnormal distance K6 is a value smaller than the operation start distance K2. Therefore, "The distance to the water surface measured by the distance sensor 22 becomes the first abnormal distance K5 or more, which corresponds to the fact that the water level of the tank 13 is remarkably lowered. The first abnormal distance. K5 is, for example, a value corresponding to the safety water level L5 of the pump 15, and the safety water level L5 is a water level at which the discharge amount of the pump 15 becomes unstable at a water level lower than this. The fact that the distance to the water surface measured by the sensor 22 is the second abnormal distance K6 or less corresponds to the fact that the water level of the tank 13 has risen significantly. As shown in FIG. 3, the second is The abnormal distance K6 is a value corresponding to a water level L6 higher than the overflow water level L1. Therefore, the cause of satisfying the above condition FE4 is that the tank 13 is not normally drained through the overflow space A2. It is also possible that the distance sensor 22 is not installed at a proper position and the water level in the tank 13 cannot be measured correctly.

Next, the processing of the control unit 80 in the deicing operation will be described. In the deicing operation, as shown in FIG. 6, the control unit 80 operates the pump motor 33 with the drain valve 21 open to drain the water in the tank 13 to the outside through the drain pipe 20. The drainage operation (wastewater treatment) is executed (step S21). Control when the water level of the tank 13 drops with drainage and the distance detected by the distance sensor 22 becomes a distance corresponding to the preset bottom surface 13A of the tank 13 (the height of the bottom surface 13A is detected). The unit 80 determines that the drainage is completed, stops the pump motor 33, closes the drain valve 21, and stops the drainage operation.

In the ice making operation of the flow-down ice maker, impurities contained in the water of the tank 13 are hard to freeze on the ice making surface 12A and are collected in the tank 13, so that the ice 57 is in a state where the impurities are extremely small (ultra pure water). ). In other words, immediately after the completion of the ice making operation, the water in the tank 13 is concentrated water having a high concentration of impurities. Such concentrated water causes scale in the circulation pathway. Therefore, it is more preferable to perform a drainage operation immediately after the ice making operation to drain the concentrated water as described above. Further, in the drainage operation, the control unit 80 increases the rotation speed of the pump motor 33 (at least higher than the low speed V3) so that the height of the water pumped by the pump 15 is the height between the ice making unit 11 and the intermediate unit 19. Control (low speed). As a result, it is possible to suppress the situation where the water in the tank 13 to be drained goes to the ice making section 11, and the drainage can be performed more reliably.

Next, the control unit 80 stops the fan 46 and opens the hot gas valve 50 (step S22). As a result, the refrigerant gas (hot gas) is supplied from the compressor 41 to the evaporation pipe 44, and the evaporation pipe 44 (and thus the ice plate 12) can be heated. Further, the control unit 80 opens the water supply valve 30 to allow tap water to flow down to the back surface of the ice plate 12 via the water supply pipe 52 (step S23). As a result, the ice making plate 12 is heated by tap water and hot gas, and the contact portion of the ice 57 with the ice making surface 12A is melted, so that the ice 57 is peeled off (deiced) from the ice making surface 12A. The deiced ice falls on the drainboard 28 and then is stored in the ice storage tank 14. Further, the tap water flowing down the back surface of the ice plate 12 falls into the tank 13, so that the water level in the tank 13 rises. When the water level in the tank 13 rises and the operation start water level becomes L2 (the distance to the water surface detected by the distance sensor 22 becomes the operation start distance K2) (“YES” in step S24), the control unit 80 determines. The water supply valve is closed to stop the water supply (step S25).

When deicing the ice 57, the deiced water in which a part of the ice 57 (the portion in contact with the ice making surface 12A) is melted is collected in the tank 13. Since such deicing water has few impurities, it is preferable to use it again for ice making without draining it. Therefore, by stopping the water supply at the operation start water level L2 lower than the overflow water level L1 as in steps S24 and S25, it is possible to suppress the situation where the defrosted water overflows and is drained.

After that, when the temperature of the ice plate 12 rises to some extent and the following condition FB1 is satisfied (“YES” in step S26), the control unit 80 operates the pump motor 33 at medium speed V2 (step S27). For example, in step S27, the pump motor 33 is operated at medium speed V2 for a predetermined time T5 (for example, 15 seconds) and then stopped, and after the predetermined time T6 (for example, 30 seconds), the pump motor 33 is operated at medium speed V2, for example. After operating T7 (for example, 15 seconds) for a predetermined time, it stops. In this way, the deicing of ice can be promoted by flowing ice-making water on the ice-making surface 12A in a state where the temperature of the ice-making plate 12 has risen to some extent.
Condition FB1: Detection temperature of ice making part temperature sensor 16 ≥ predetermined temperature C4 (for example, 4 ° C)
In the state where the contact portion of the ice 57 with the ice making surface 12A is melted, the ice 57 is hard to be peeled off from the ice making surface 12A due to the surface tension of water between the ice 57 and the ice making surface 12A. Therefore, as described above, after the contact portion with the ice making surface 12A is melted on the ice 57, the pump motor 33 is operated to flow the ice making water on the ice making surface 12A, so that the ice 57 is knocked down by the force of water. By doing so, deicing can be promoted. However, when the refrigerant gas (hot gas) is supplied to the evaporation pipe 44 from the compressor 41, the inlet side of the evaporation pipe 44 (the side closer to the hot gas valve 50, corresponding to the upper part of the ice plate 12) is the outlet of the evaporation pipe 44. It is easier to warm up than the side (corresponding to the ice making part temperature sensor 16 side and the lower part of the ice making plate 12). That is, the ice 57 on the upper side of the ice making surface 12A melts quickly in contact with the ice making surface 12A. Therefore, in the present embodiment, first, by operating the pump motor 33 at medium speed V2 for a predetermined time T5, the ice 57 on the upper part of the ice making surface 12A (about the upper half of the ice making surface 12A), which is relatively easy to melt, is removed. Let it ice. After that, by allowing T6 to elapse for a predetermined time, the contact portion of the ice 57 below the ice making surface 12A with the ice making surface is melted, and then the pump motor 33 is operated at medium speed V2 for a predetermined time T7, so that the lower ice is formed. I try to de-ice 57.

Then, the control unit 80 satisfies all of the following conditions FB2 (“YES” in step S28) and then when a predetermined time T8 (for example, 60 seconds) elapses (“YES” in step S29) on the ice making surface 12A. It is determined that the ice has been de-iced, the de-icing operation is stopped, and the ice-making operation is started. The predetermined temperatures C4 and C5 can be appropriately set, but the predetermined temperatures C4 and C5 are set at a temperature higher than 0 ° C., and the predetermined temperature C5 is set at a temperature higher than the predetermined temperature C4.
Condition FB2: Detection temperature of ice making part temperature sensor 16 ≥ predetermined temperature C5 (for example, 9 ° C.)

In the control unit 80, the distance to the upper surface 14D of the ice measured by the ice storage unit side distance sensor 23 (corresponding to the amount of ice stored in the ice storage tank) becomes a preset predetermined distance K7 (corresponding to the preset predetermined distance K7). Repeat the ice making operation and the ice removing operation until the amount of ice in the ice storage tank reaches a predetermined amount. Further, since the predetermined distance K7 (the amount of ice in the ice storage tank) can be set as appropriate, the amount of ice in the ice storage tank 14 can be adjusted. When performing the second and subsequent ice making operations, the control unit 80 may omit the water supply process (process of supplying tap water up to the operation start water level L2) executed before the ice making operation.

Further, the control unit 80 executes the washing operation after the ice removing operation on condition that the ice making operation and the ice removing operation cycle are executed a predetermined number of times (for example, 20 times). Next, the processing of the control unit 80 in the cleaning operation will be described. In the cleaning operation, as shown in FIG. 7, the control unit 80 stops the cooling device 40 (compressor 41 and fan 46) and closes the hot gas valve 50 (step S41). Next, the control unit 80 supplies water to the tank by opening the water supply valve 30 (step S42), and based on the distance to the water surface (water level in the tank 13) measured by the distance sensor 22, the inside of the tank 13 When the water level reaches a predetermined water level (for example, overflow water level L1) (“YES” in step S43), the water supply valve is closed (step S44).

Next, the control unit 80 operates the pump motor 33 with the cooling device 40 stopped, and opens the valve 34 to generate water between the tank 13 and the ice making unit 11 (the front surface and the back surface of the ice plate 12). To circulate. In the cleaning operation, the control unit 80 alternately repeats the process of lowering the rotation speed of the pump motor 33 and the process of increasing the rotation speed of the pump motor 33. Specifically, the control unit 80 performs the first operation process of operating the pump motor 33 at the high-speed V4A during cleaning, which is a rotation speed higher than the high-speed V1, for a predetermined time (step S45), and then at the low-speed V4B during cleaning. A second operation process for operating for a predetermined time is performed (step S46). The control unit 80 alternately and repeatedly executes the first operation process and the second operation process. Then, when the control unit 80 executes the first operation process and the second operation process a predetermined number of times (“YES” in step S47), the control unit 80 opens the drain valve 21 and closes the valve 34, and the pump motor. By operating 33, a drainage operation (drainage treatment) for draining the water in the tank 13 is executed (step S48). As a result, the cleaning operation is stopped. The control unit 80 shifts to the ice making operation after the washing operation is stopped.

Further, in the above embodiment, the washing operation is executed on the condition that the cycle of the ice making operation and the deicing operation is executed a predetermined number of times, but the present invention is not limited to this. The concentration of impurities contained in the water in the tank 13 is measured by a sensor, and when the concentration of impurities exceeds a predetermined value, the control unit 80 may execute a washing operation after the deicing operation. good. The higher the concentration of impurities in water, the higher the electrical conductivity. Therefore, in the present embodiment, an electric conductivity sensor capable of measuring the electric conductivity may be provided. Such an electric conductivity sensor is electrically connected to the control unit 80, and the electric conductivity of water is measured by the electric conductivity sensor, and the control unit 80 measures the measured electric conductivity to a predetermined value or more. When the concentration of impurities reaches a predetermined value or more, the cleaning operation may be executed. The water temperature sensor 17 is configured by, for example, housing the thermistor in a metal case 17A (the outer shell portion of the water temperature sensor 17, see FIG. 3). When the water temperature sensor 17 having such a configuration is used, as shown by the alternate long and short dash line in FIG. 3, the electrode 48 arranged in contact with the water in the tank 13 may be provided. The electrodes 48 are arranged at intervals from the case 17A, and the electrodes 48 and the case 17A are electrically connected to the control unit 80. The control unit 80 energizes both the electrode 48 and the case 17A to pass an electric current through the water between the electrode 48 and the case 17A, and measures the electric resistance of the water to measure the electricity of the water in the tank 13. Conductivity can be measured. That is, one of the pair of electrodes constituting the electrical conductivity sensor (for example, the positive electrode) may be formed of the electrode 48, and the other electrode (for example, the negative electrode) may be formed of the case 17A.

Further, as shown in FIG. 1, the present embodiment includes a UV sterilizer 70 that sterilizes the water in the tank 13 by irradiating the water in the tank 13 with ultraviolet rays. The UV sterilizer 70 is an ultraviolet lamp or a deep ultraviolet LED lamp, and is capable of irradiating, for example, ultraviolet rays (UV) having a wavelength of 253 nm to 285 nm, which has a high sterilizing effect on water. The UV sterilizer 70 is fixed to the lid 27 of the tank 13, for example, and can irradiate the water stored in the tank 13 with ultraviolet rays.

In the present embodiment, even when drainage is performed by the pump 15, water is partially discharged in the water circulation path (including the tank 13 and the ice making section 11) between the tank 13 and the ice making section 11. There are concerns about the remaining situation. In the following explanation, the water that cannot be completely drained and remains in the circulation path is called residual water. As an example of the place where residual water is generated, for example, the bottom of the tank 13 can be mentioned. Since a water suction port (not shown) is provided at the lower end of the pump 15, in order to suck water by the pump 15, for example, as shown in FIG. 1, a recess 13D is provided on the bottom surface 13A of the tank 13 to provide a recess. It is necessary to provide a gap between the bottom surface 13E of the 13D and the lower end of the pump 15. Under these circumstances, for example, at the bottom of the tank 13 (recessed portion 13D), there is a small amount of residual water that cannot be sucked by the pump 15. If the ice making operation is not executed for a long time, it is expected that the temperature of the residual water will rise. If the temperature of the residual water rises, there is concern that the bacteria will grow.

Therefore, in the present embodiment, the control unit 80 executes a residual water treatment operation for treating the residual water. In the residual water treatment operation, as shown in FIG. 9, the following first treatment to fourth treatment are executed in order. In the first treatment (residual water dilution treatment, step S51), the control unit 80 supplies water (tap water) from the water pipe 31 to the tank 13 by opening the water supply valve 30. As a result, the water (residual water) in the tank 13 is diluted with the supplied water. Then, in the first process, the control unit 80 continues to supply water for a predetermined time after the water level in the tank 13 measured by the distance sensor 22 reaches the overflow water level L1 (see FIG. 3), and then the water supply valve 30 Close. As a result, a part of the water in the diluted tank 13 is drained from the overflow space A2.

In the second process (water circulation process, step S52) executed after the first process, the control unit 80 operates the pump motor 33 for a predetermined time with the cooling device 40 stopped and the valve 34 open. Water is circulated between the tank 13 and the ice making section 11 (including the front surface and the back surface of the ice making plate 12). As a result, the residual water remaining in the circulation path other than the tank 13 can be sent to the tank 13 by flowing the residual water by the circulating water.

In the third treatment (residual water drainage treatment, step S53) executed after the second treatment, the control unit 80 operates the pump motor 33 with the drainage valve 21 open and the valve 34 closed. Then, the water in the tank 13 is drained to the outside through the drain pipe 20. Control when the water level of the tank 13 drops with drainage and the distance detected by the distance sensor 22 becomes a distance corresponding to the preset bottom surface 13A of the tank 13 (the height of the bottom surface 13A is detected). The unit 80 determines that the drainage is completed, stops the pump motor 33, closes the drainage valve 21, and stops the third process. Further, in the third process, the control unit 80 controls the rotation speed of the pump motor 33 so that the height of the water pumped by the pump 15 is the height between the ice making unit 11 and the intermediate portion 19. As a result, it is possible to suppress the situation where the water in the tank 13 goes to the ice making section 11, and it is possible to drain the water more reliably.

In the fourth process (sterilization process, step S54) executed after the third process, the control unit 80 operates the UV sterilizer 70 for a predetermined time to allow the water in the tank 13 (the water in the tank 13 to be completely drained). (Water remaining in) is sterilized.

As shown in FIG. 10, the control unit 80 has a predetermined time T11 (for example, 4 hours) in a state where neither the ice making operation nor the deicing operation is executed (in other words, the cooling device 40 is stopped). Residual water treatment operation (first treatment, second treatment, third treatment, fourth treatment, steps S51 to S54) is executed every time the elapses. That is, the control unit 80 periodically executes the residual water treatment operation when the ice making operation or the ice removing operation is not executed.

Further, as shown in FIG. 11, the control unit 80 performs the residual water treatment operation (first treatment to fourth treatment) when the power supply of the ice maker 10 is switched from the off state to the on state (“YES” in step S61). Process) is executed (step S62). The user can switch the power supply of the ice machine 10 between the on state and the off state by operating the power switch of the operation unit 55, for example.

Next, the effect of this embodiment will be described. The ice machine 10 of the present embodiment can change the rotation speed of the ice making unit 11 that produces ice by freezing water, the cooling device 40 that cools the ice making unit 11, and the tank 13 that stores water. A pump 15 including a pump motor 33, the pump 15 capable of supplying water in the tank 13 to the ice making unit 11 as the pump motor 33 is driven, and a control unit 80, and the tank 13 includes a control unit 80. Of the water supplied to the ice making section 11, the unfrozen water is stored in the tank 13, and the control section 80 operates the cooling device 40 and the pump motor 33 to cause the ice making section 11 to operate. It is assumed that an ice making operation for producing ice is executed, and in the ice making operation, the rotation speed of the pump motor 33 is controlled.

In the above configuration, water (ice making water) can be circulated between the tank 13 and the ice making section 11 by driving the pump motor 33. Further, by increasing or decreasing the rotation speed of the pump motor 33, the amount of ice-making water circulating between the tank 13 and the ice-making unit 11 can be increased or decreased. In the initial stage of the ice making operation, it is preferable to efficiently cool the ice making water in the ice making section 11 by operating the pump motor 33 at a relatively high rotation speed (high speed V1) and increasing the circulation amount of the ice making water. However, if the ice-making water is sufficiently cooled and the circulation amount of the ice-making water continues to be large, there is a concern that the supercooling of the ice-making water causes cotton ice to be generated in the tank 13 and hinders the circulation of the ice-making water. In the above configuration, since the control unit 80 can reduce the rotation speed of the pump motor 33 (set to low speed V3) during the ice making operation, the ice making water circulates between the tank 13 and the ice making unit 11 at a predetermined timing. The amount can be reduced and the generation of cotton ice can be suppressed.

Further, the ice making unit temperature sensor 16 capable of detecting the temperature of the ice making unit 11 is provided, and the control unit 80 has a predetermined temperature C2 in which the temperature detected by the ice making unit temperature sensor 16 is higher than 0 ° C. during the ice making operation. In the following cases, the rotation speed of the pump motor 33 is lowered, and after a predetermined time has elapsed, the rotation speed of the pump motor 33 is increased.

In the ice making operation, the ice making water is cooled, and the temperature of the ice making section 11 is lowered accordingly. When the rotation speed of the pump motor 33 is lowered in a state where the temperature of the ice making section 11 is lower than a predetermined temperature (a temperature higher than 0 ° C.) (a state in which the ice making water is sufficiently cooled), the flow rate of the ice making water in the ice making section 11 increases. As the temperature drops and the temperature of the ice making section 11 further drops, seed ice is likely to occur in the ice making section 11. When seed ice is generated, the ice grows around the seed ice as a core. If there is ice in the ice making section 11, the heat exchange efficiency in the ice making section 11 is lowered, so that the ice making water is hard to be cooled and supercooling is hard to occur. Therefore, the rotation speed of the pump motor 33 is lowered (low speed V3), and after the seed ice is formed after a predetermined time elapses, the rotation speed of the pump motor 33 is increased (medium speed V2). , Ice production can be performed faster while suppressing the generation of cotton ice.

Further, a water temperature sensor 17 capable of detecting the temperature of the water stored in the tank 13 is provided, and the control unit 80 has a predetermined temperature C1 in which the temperature detected by the water temperature sensor 17 is higher than 0 ° C. during the ice making operation. In the following cases, the rotation speed of the pump motor 33 is lowered, and after a predetermined time has elapsed, the rotation speed of the pump motor 33 is increased.

In the ice making operation, since the ice making water that has passed through the ice making section 11 is stored in the tank 13, the water temperature of the tank 13 follows the temperature of the ice making water in the ice making section 11. When the rotation speed of the pump motor 33 is lowered in a state where the water temperature of the tank 13 is below a predetermined temperature (a temperature higher than 0 ° C.) (the ice making water is sufficiently cooled), the flow rate of the ice making water in the ice making section 11 decreases. However, as the temperature of the ice making section 11 further decreases, seed ice is likely to occur in the ice making section 11. When seed ice is generated, the ice grows around the seed ice as a core. If there is ice in the ice making section 11, the heat exchange efficiency in the ice making section 11 is lowered, so that the ice making water is hard to be cooled and supercooling is hard to occur. Therefore, by lowering the rotation speed of the pump motor 33 and increasing the rotation speed of the pump motor 33 after the seed ice is formed after a lapse of a predetermined time, the generation of cotton ice is suppressed and the ice is formed. Manufacturing can be done faster.

Further, the pump motor 33 is a DC motor, and the control unit 80 normally circulates water between the tank 13 and the ice making unit 11 when the rotation speed of the pump motor 33 becomes equal to or lower than a predetermined rotation speed. Judge that it has not been done. If scale precipitates in the water circulation path between the tank 13 and the ice making section 11, the water circulation is hindered and the load acting on the pump motor 33 increases, so that the rotation speed of the pump motor 33 decreases. Therefore, when the rotation speed becomes equal to or lower than the predetermined rotation speed, the control unit 80 can determine that the water circulation between the tank 13 and the ice making unit 11 is not normally performed.

Further, the pump motor 33 is a DC motor, and the control unit 80 normally circulates water between the tank 13 and the ice making unit 11 when the current value of the pump motor 33 becomes equal to or higher than a predetermined current value. Judge that it is not done. If scale precipitates in the water circulation path between the tank 13 and the ice making section 11, the water circulation is hindered and the load acting on the pump motor 33 increases, so that the current of the pump motor 33 increases. Therefore, when the current value of the pump motor 33 becomes equal to or higher than the predetermined current value, the control unit 80 determines that the water circulation between the tank 13 and the ice making unit 11 is not normally performed. Can be done.

Further, the tank 13 is provided with a distance sensor 22 (water level sensor) capable of measuring the water level of the water stored in the tank 13, and the ice making section 11 is provided with an ice making plate 12 having an ice making surface 12A through which water flows down. Is arranged below the ice plate 12, and the control unit 80 gradually lowers the rotation speed of the pump motor 33 as the water level in the tank 13 measured by the distance sensor 22 decreases during the ice making operation. Perform processing.

In the above configuration, the water level of the tank 13 becomes lower as the ice on the ice making surface 12A grows (becomes larger). Further, in the process of water flowing down the ice making surface 12A, the water may be repelled by the ice on the ice making surface 12A and scattered, and the larger the ice, the larger the amount of water scattered. Therefore, as the water level becomes lower, the rotation speed of the pump motor 33 is gradually lowered, so that the amount of water scattered can be reduced and the water can be returned to the tank 13 more reliably. Further, by lowering the rotation speed of the pump motor 33, the amount of water in the circulation path of the tank 13 and the ice plate 12 can be reduced. Since the water in the circulation path is not used for ice making, it is possible to save water by reducing the amount of such water.

Further, the control unit 80 is supposed to execute a cleaning operation of circulating water between the tank 13 and the ice making unit 11 by operating the pump motor 33 with the cooling device 40 stopped, and during the cleaning operation. , The process of lowering the rotation speed of the pump motor 33 and the process of increasing the rotation speed of the pump motor 33 are alternately repeated. In the washing operation, the water circulation path can be washed by circulating water between the tank 13 and the ice making section 11. Then, in the cleaning operation, water can be pulsated in the circulation path by repeating increasing and decreasing the rotation speed of the pump motor 33, and dirt (scale, etc.) in the circulation path can be efficiently removed by the pressure of water. Therefore, the water circulation path can be washed more efficiently.

Further, a pipe 18 connecting the ice making unit 11 and the pump 15, a drain pipe 20 drawn from the intermediate portion 19 of the pipe 18 for draining the water in the tank 13 to the outside, and a drain pipe 20 for opening and closing the drain pipe 20 are opened and closed. The ice making unit 11 is provided at a position higher than the pump 15 and includes a valve 21, and the control unit 80 operates the pump motor 33 with the drain valve 21 open to operate the drain pipe 20. It is assumed that the drainage operation of draining the water in the tank 13 to the outside is executed through the drainage operation, so that the height of the water pumped by the pump 15 is the height between the ice making section 11 and the intermediate section 19. The rotation speed of the pump motor 33 is controlled. By operating the pump 15, in addition to supplying water to the ice making section 11, the water in the tank 13 can be drained. Since the height (lift) of the water pumped by the pump 15 in the drainage operation is set to be the height between the ice making section 11 and the intermediate section 19, the water in the tank 13 reaches the ice making section 11. The situation can be suppressed and drainage can be performed reliably.

Further, an ice making section 11 that produces ice by freezing water, a cooling device 40 that cools the ice making section 11, a tank 13 that can store water supplied to the ice making section 11, and a tank 13 that can store water. It is provided with a distance sensor 22 which is arranged above the water and can measure the distance of the water stored in the tank 13 to the water surface. As the water level in the tank 13 rises, the distance from the distance sensor 22 to the water surface decreases. Therefore, the water level in the tank 13 can be detected by measuring the distance from the distance sensor 22 to the water surface. If, as shown in the ice maker 1 of the comparative example of FIG. 8, the float switch 2 is used to detect the water level of the water in the tank 13, the float 3 (float) in contact with the water is used. ), The height of the float 3 changes due to the adhesion of foreign matter such as scale, and there is a concern that the water level cannot be detected accurately. Since the distance sensor 22 having the above configuration can suppress the situation of contact with water, the water level can be detected more accurately.

Further, the float switch cannot measure the water level linearly because the detectable water level is fixed. For example, as shown in FIG. 8, when the float switch 2 capable of detecting only two water levels L11 and L12 is used, the operation start water level of the ice making operation is set to the water level L11 and the operation stop water level is set to the water level L12. It is conceivable to carry out an ice making operation. In this case, since the amount of ice produced is determined by the difference between L11 and L12, the amount of ice produced by the ice making operation will be the same each time.

Further, when the float switch is used, the water in the tank 13 overflows from the upper end of the vertical wall portion 32 to the overflow space A2 by supplying water for a predetermined time after the water level in the tank 13 reaches L11 with the water supply. It is conceivable to set the water level L13 (overflow water level) at that time as the operation start water level and execute the ice making operation until the operation stop water level L12 is reached. Even in this case, the amount of ice made is determined by the difference between L13 and L12, so that the amount of ice made is the same each time. In addition, the water in the tank 13 will overflow, which is not preferable from the viewpoint of water saving. In the present embodiment, by using the distance sensor 22, the operation start water level L2 and the operation stop water level L4 can be set at a predetermined water level, and the amount of ice produced by the ice making operation can be changed.

Further, the distance sensor 22 has a configuration capable of measuring the distance to the water surface by irradiating the water surface with ultrasonic waves. According to the distance sensor 22 having the above configuration, the water level of the water in the tank 13 can be measured by measuring the distance to the water surface using ultrasonic waves. If the distance sensor 22 is configured to irradiate the water surface with a laser, the laser may not be reflected on the water surface and may go into the water, making it difficult to accurately measure the distance to the water surface. Since ultrasonic waves can be reflected more reliably on the water surface, the distance to the water surface can be measured more reliably.

Further, the pump 15 including the pump motor 33, the pump 15 capable of supplying the water in the tank 13 to the ice making unit 11 as the pump motor 33 is driven, and the control unit 80 are provided in the tank. Reference numeral 13 denotes a configuration in which unfrozen water among the water supplied to the ice making unit 11 is stored in the tank 13, and the control unit 80 operates the cooling device 40 and the pump motor 33 to operate the ice making unit 11. When the ice-making operation for producing ice is executed in the ice-making operation and the distance to the water surface detected by the distance sensor 22 becomes the preset operation start distance K2, the ice-making operation is started and the distance is reached. When the distance to the water surface detected by the sensor 22 reaches the operation stop distance K4, which is larger than the operation start distance K2, the ice making operation is stopped. In the ice making operation, the water in the tank 13 becomes ice in the ice making section. Therefore, the difference between the operation start distance K2 and the operation stop distance K4 is proportional to the amount of ice produced in the ice making section 11. Therefore, the amount of ice produced in the ice making section 11 can be changed by setting the operation start distance K2 and the operation stop distance K4, respectively.

Further, the tank 13 is configured so that when the water in the tank 13 exceeds the predetermined overflow water level L1, the water exceeding the overflow water level L1 can be drained to the outside of the tank 13, and the operation start distance K2 The water level (operation start water level L2) corresponding to is lower than the overflow water level L1. Since the ice making operation is started at a water level lower than the overflow water level L1, it is possible to suppress a situation in which the water in the tank 13 is drained beyond the overflow water level L1 during the ice making operation.

Further, the control unit 80 has a value when the distance to the water surface measured by the distance sensor 22 is equal to or greater than the first abnormal distance K5, which is a value larger than the operation stop distance K4, or a value smaller than the operation start distance K2. When the second abnormal distance is K6 or less, an error notification process for notifying an error is executed. When the water level in the tank 13 becomes extremely low (when the first abnormal distance K5 or more) or when the water level in the tank 13 becomes extremely high (when the second abnormal distance K6 or less) By notifying the error, it is possible to notify the operator of the abnormality of the water level in the tank 13.

Further, an ice storage tank 14 (ice storage unit) capable of storing ice produced in the ice making unit 11 and an upper surface 14D of ice arranged above the ice stored in the ice storage tank 14 and stored in the ice storage tank 14 The ice storage unit side distance sensor 23 capable of measuring the distance to the ice storage unit is provided. As the amount of ice stored in the ice storage tank 14 increases, the upper surface of the ice becomes higher, so that the distance from the ice storage portion side distance sensor 23 to the upper surface of the ice becomes smaller. As a result, by providing the ice storage unit side distance sensor 23, the amount of ice stored in the ice storage tank 14 can be measured. This makes it possible to make ice according to the amount of ice stored in the ice storage tank 14. Further, the control unit 80 may display the amount of ice measured by the ice storage unit side distance sensor 23 on the display unit 56.

Further, a water supply pipe 29 for supplying water from a water pipe 31 (external water source) to the tank 13, a water supply valve 30 for opening and closing the water supply pipe 29, and a pipe 18 for connecting the ice making section 11 and the pump 15 The control unit 80 includes a drain pipe 20 for draining the water in the tank 13 to the outside, and a drain valve 21 for opening and closing the drain pipe 20, which is drawn from the intermediate portion 19 of the pipe 18. The first process of supplying water from the water pipe 31 to the tank 13 by opening the tank 13 and the first process are executed after the first process, and the pump motor 33 is operated with the cooling device 40 stopped to make the tank 13 and ice. The second treatment for circulating water between the parts 11 and the second treatment, which is executed after the second treatment, operates the pump motor 33 with the drain valve 21 open to allow the water in the tank 13 to flow through the drain pipe 20. The third treatment of draining water to the outside is performed regularly.

When the ice making operation is executed, the water circulating between the tank 13 and the ice making section 11 becomes cold. On the other hand, when the state in which the ice making operation is not executed continues for a long time, the water temperature of the water remaining in the water circulation path between the tank 13 and the ice making section 11 (hereinafter, simply referred to as a circulation path) rises. It is conceivable that the bacteria can easily propagate. By executing the first treatment to the third treatment, the water remaining in the circulation path can be washed with the supplied water and drained. By periodically executing such first to third processes, it is possible to maintain the inside of the circulation path in a cleaner state even when the state in which the ice making operation is not executed continues for a long time.

Further, the control unit 80 executes the first process, the second process, and the third process when the power supply of the ice machine 10 is switched from the off state to the on state. If water remains in the circulation path and the power of the ice maker 10 is turned off for a long time, it remains in the circulation path due to reasons such as the ice making operation and the above-mentioned periodic residual water treatment operation not being executed. It is conceivable that the temperature of the fresh water will rise and the bacteria will grow more easily. Therefore, when the power is switched to the on state, the first process to the third process are periodically executed in this order to make the inside of the circulation path clean before executing the ice making operation. can.

Further, a UV sterilizer 70 for sterilizing the water in the tank 13 by irradiating the water in the tank 13 with ultraviolet rays is provided, and the control unit 80 operates the UV sterilizer 70 after executing the third treatment. Then, the fourth treatment for sterilizing the water in the tank 13 is executed. The water in the tank 13 that could not be completely drained by the third treatment can be sterilized by the UV sterilizer. As a result, the inside of the tank 13 can be made cleaner. In the present embodiment, when the water pipe 31 is provided with a water purifier for removing chlorine, bacteria are more likely to grow in the residual water. Therefore, it is particularly preferable to carry out the first to fourth treatments described above in the case of a configuration in which a water purifier is provided.

<Other Embodiments>
The present invention is not limited to the embodiments described in the above description and drawings, and for example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above embodiment, the flow-down type ice maker is illustrated, but the method of the ice maker is not limited to the flow-down type. The techniques described herein are also applicable to other types of ice machines (eg cell type) in which water circulates between the tank and the ice making section.
(2) In the above embodiment, the distance sensor 22 using ultrasonic waves has been illustrated, but the distance sensor 22 is not limited to this. As the distance sensor 22, a sensor 22 that measures the distance to the water surface by irradiating the water surface with a laser may be used. If the laser is difficult to reflect on the water surface, a reflective member with high light reflectance (for example, a cylindrical float) is floated on the water surface, and the laser is irradiated toward the reflective member to increase the distance to the water surface. It may be configured to measure. Further, as the water level sensor for measuring the water level in the tank 13, a water level sensor other than the distance sensor may be used.
(3) In the additional water supply treatment of the above embodiment (step S4 in FIG. 5), for example, the water level of the tank 13 is supplied to the same level as the overflow water level L1, the water level is set as the operation start water level, and the water level is lower than this water level by a predetermined value. The water level may be the shutdown water level. Further, the water level at that time may be set as the operation start water level, and the water level lower than this water level by a predetermined value may be set as the operation stop water level without executing the additional water supply treatment. Further, in the additional water supply treatment, the control unit 80 supplies the water level of the tank 13 to the same level as the overflow water level L1, then supplies water for a predetermined time, and sets the water level (overflow water level) at that time as the operation start water level. A water level lower than this water level by a predetermined value may be set as the operation stop water level.
(4) In the additional water supply treatment (step S4 in FIG. 5), when the water level of the tank 13 is supplied to the same level as the overflow water level L1, the ice-making water is made after the water level reaches the overflow water level L1 (operation start water level). Water supply may be continued until the temperature of the ice making section becomes a certain low temperature (until the detection temperature of the ice making section temperature sensor 16 or the water temperature sensor 17 becomes a predetermined temperature (for example, 5 ° C.) or less). When the pump 15 is operated to cool the ice-making water, the water scatters in the process of flowing down the ice-making surface 12A. When the water scatters, the water level of the tank 13 drops, so that ice is made from a water level lower than the operation start water level to an operation end water level, and ice smaller than a desired size is made. By continuing to supply water until the ice-making water reaches a certain low temperature (a temperature close to 0 ° C.), it is possible to replenish the amount of water scattered on the ice-making plate while cooling the ice-making water, so that the water in the tank 13 can be replenished. Since the water level can be maintained at the overflow water level L1, which is the operation start water level, and the amount of water reduced from the operation start water level to the operation stop water level can be turned into ice, ice of a desired size can be made more reliably. can do.
(5) In the above embodiment, it is illustrated that the ice making operation is started by the user operating the operation unit 55, but the present invention is not limited to this. For example, in the control unit 80, when the distance to the upper surface of the ice (the amount of ice stored in the ice storage tank 14) measured by the ice storage unit side distance sensor 23 becomes equal to or more than a preset predetermined distance (ice storage). The ice making operation may be started when the amount of ice in the tank 14 is less than a predetermined amount). That is, the control unit 80 may start the ice making operation based on the amount of ice stored in the ice storage tank 14.
(6) The control unit 80 may execute an error notification process for notifying an error when the above condition FE3 or condition FE4 is satisfied for a predetermined time during the deicing operation or the washing operation.
(7) In the above embodiment, the predetermined temperature C1, C2, C3, C4, C5 and the predetermined time T1, T3, T4, T5, T6, T7, T8, T9, T10 are not limited to the illustrated numerical values. , Can be set as appropriate.
(8) In the residual water treatment operation, the control unit 80 may not execute the fourth treatment but execute only the first treatment to the third treatment.

10 ... ice machine, 11 ... ice making section, 12 ... ice making plate, 12A ... ice making surface, 13 ... tank, 14 ... ice storage tank (ice storage section), 14D ... top surface of ice stored in the ice storage section, 15 ... pump, 16 ... Ice making part temperature sensor, 17 ... Water temperature sensor, 18 ... Piping connecting the ice making part and the pump, 19 ... Middle part of the piping, 20 ... Drain pipe, 21 ... Drain valve that opens and closes the drain pipe, 22 ... Distance sensor ( Water level sensor), 23 ... Ice storage side distance sensor, 29 ... Water supply pipe, 30 ... Water supply valve, 33 ... Pump motor, 40 ... Cooling device, 58 ... Water surface (water surface of water stored in tank), 70 ... UV sterilization Device, 80 ... Control unit, K2 ... Operation start distance, K4 ... Operation stop distance, K5 ... First abnormal distance, K6 ... Second abnormal distance, L1 ... Overflow water level

Claims (11)

An ice making department that produces ice by freezing water,
A cooling device that cools the ice making part,
A tank to store water and
A pump including a pump motor capable of changing the rotation speed, and a pump capable of supplying water in the tank to the ice making section as the pump motor is driven.
With a control unit
The tank has a configuration in which, of the water supplied to the ice making section, unfrozen water is stored in the tank.
The control unit is supposed to execute an ice making operation for producing ice in the ice making unit by operating the cooling device and the pump motor. In the ice making operation, the ice making machine controls the rotation speed of the pump motor. .. Equipped with an ice making part temperature sensor capable of detecting the temperature of the ice making part,
The control unit lowers the rotation speed of the pump motor when the temperature detected by the ice making unit temperature sensor becomes a predetermined temperature higher than 0 ° C. during the ice making operation, and after a predetermined time elapses, the control unit reduces the rotation speed of the pump motor. The ice maker according to claim 1, wherein the process of increasing the rotation speed of the pump motor is performed. A water temperature sensor capable of detecting the temperature of the water stored in the tank is provided.
The control unit lowers the rotation speed of the pump motor when the temperature detected by the water temperature sensor becomes equal to or lower than a predetermined temperature higher than 0 ° C. during the ice making operation, and after a predetermined time elapses, the pump The ice maker according to claim 1, wherein a process for increasing the rotation speed of the motor is performed. The pump motor is a DC motor.
From claim 1, the control unit determines that water circulation between the tank and the ice making unit is not normally performed when the rotation speed of the pump motor becomes equal to or lower than a predetermined rotation speed. The ice maker according to any one of claims 3. The pump motor is a DC motor.
From claim 1, the control unit determines that water circulation between the tank and the ice making unit is not normally performed when the current value of the pump motor becomes a predetermined current value or more. The ice maker according to any one of claims 4. A water level sensor capable of measuring the water level of the water stored in the tank is provided.
The ice making section includes an ice making plate having an ice making surface on which water flows down.
The tank is arranged below the ice plate.
Any one of claims 1 to 5, wherein the control unit performs a process of gradually lowering the rotation speed of the pump motor as the water level measured by the water level sensor becomes lower during the ice making operation. The ice machine described in. The control unit is supposed to execute a cleaning operation of circulating water between the tank and the ice making unit by operating the pump motor with the cooling device stopped.
The ice maker according to any one of claims 1 to 6, wherein during the washing operation, a process of lowering the rotation speed of the pump motor and a process of increasing the rotation speed of the pump motor are alternately repeated. A pipe connecting the ice making section and the pump,
A drainage pipe drawn from the middle part of the pipe to drain the water in the tank to the outside,
A drain valve for opening and closing the drain pipe is provided.
The ice making section is arranged at a position higher than that of the pump.
The control unit operates the pump motor with the drain valve open to execute a drainage operation for draining the water in the tank to the outside through the drain pipe.
In the drainage operation, any one of claims 1 to 7, wherein the rotation speed of the pump motor is controlled so that the height of the water pumped by the pump is the height between the ice making section and the intermediate section. The ice machine according to item 1. A water supply pipe for supplying water from an external water source to the tank,
A water supply valve that opens and closes the water supply pipe,
A pipe connecting the ice making section and the pump,
A drainage pipe drawn from the middle part of the pipe to drain the water in the tank to the outside,
A drain valve for opening and closing the drain pipe is provided.
The control unit
The first treatment of supplying water from the external water source to the tank by opening the water supply valve, and
A second process, which is executed after the first process and causes water to circulate between the tank and the ice making section by operating the pump motor with the cooling device stopped.
It is executed after the second treatment, and by operating the pump motor with the drain valve open, the third treatment of draining the water in the tank to the outside through the drain pipe is periodically executed. The ice maker according to any one of claims 1 to 6. The ice maker according to claim 9, wherein the control unit executes the first process, the second process, and the third process when the power supply of the ice maker is switched from the off state to the on state. A UV sterilizer for sterilizing the water in the tank by irradiating the water in the tank with ultraviolet rays is provided.
The ice maker according to claim 9 or 10, wherein the control unit executes the fourth process of sterilizing the water in the tank by operating the UV sterilizer after executing the third process. ..

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