JP7321944B2 - ice machine - Google Patents

Description

The present invention relates to an ice maker.

2. Description of the Related Art Conventionally, as an ice maker, for example, 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 Literature 1, water that has not frozen in the ice making section is returned to the tank. Therefore, it is possible to circulate water (ice-making water) between the tank and the ice-making section by means of a pump.

Japanese Patent No. 5448618

By the way, as the pump motor provided in the pump for circulating water between the tank and the ice making section, an AC motor with a constant rotational 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 is performed to make ice in the ice-making unit, if the water circulation rate is large, the ice-making water is likely to be supercooled, and there is concern that cotton ice may occur. However, if the water circulation rate is reduced so as not to generate cotton ice, it takes time to cool the ice-making water at the beginning of the ice-making operation, resulting in a decrease in ice-making efficiency. Under these circumstances, there is a demand for an ice-making machine that can increase or decrease the amount of water circulated between the tank and the ice-making section during the ice-making operation.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ice making machine capable of increasing or decreasing the amount of water circulating between the tank and the ice making section.

As means for solving the above problems, the ice making machine disclosed in this specification includes an ice making section that makes ice by freezing water, a cooling device that cools the ice making section, and a tank that stores water. a pump having a pump motor capable of changing a rotational speed, the pump being 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 to store unfrozen water out of the water supplied to the ice making unit, and the control unit operates the cooling device and the pump motor to and an ice making operation for making ice in the ice making section, wherein the ice making operation is characterized by controlling the rotational speed of the pump motor.

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 rotational speed of the pump motor, the amount of ice making water circulating between the tank and the ice making section can be increased or decreased. At the beginning of the ice-making operation, it is preferable to efficiently cool the ice-making water in the ice-making unit by operating the pump motor at a relatively high rotational speed and increasing the circulation amount of the ice-making water. However, if the ice-making water is sufficiently cooled and a large amount of ice-making water circulates, there is a concern that overcooling of the ice-making water may cause fluff ice to occur in the tank, hindering circulation of the ice-making water. With the above configuration, the controller can reduce the rotation speed of the pump motor during the ice making operation, so that the amount of ice making water circulated between the tank and the ice making section can be reduced at a predetermined timing, and cotton ice can be obtained. can be suppressed.

An ice-making unit temperature sensor capable of detecting the temperature of the ice-making unit is provided, and the control unit controls the temperature detected by the ice-making unit temperature sensor during the ice-making operation so that the temperature detected by the ice-making unit temperature sensor is higher than 0° C. In such a case, the rotation speed of the pump motor may be reduced, and after a predetermined time has elapsed, the rotation speed of the pump motor may be increased.

In the ice-making operation, the ice-making water is cooled, which lowers the temperature of the ice-making section. If the rotation speed of the pump motor is reduced when the temperature of the ice-making unit is below a predetermined temperature (higher than 0° C.) (the ice-making water is sufficiently cooled), the flow rate of the ice-making water in the ice-making unit decreases. As the temperature of the ice-making unit is further lowered, seed ice is more likely to be produced in the ice-making unit. When the seed ice is generated, ice grows with the seed ice as a nucleus. If there is ice in the ice-making unit, the heat exchange efficiency in the ice-making unit is lowered, making it difficult to cool the ice-making water, making it difficult for overcooling to occur. For this reason, the rotation speed of the pump motor is reduced, and after seed ice is formed after a predetermined period of time has elapsed, the rotation speed of the pump motor is increased, thereby suppressing the occurrence of cotton ice and making ice. can be done faster.

Further, a water temperature sensor capable of detecting the temperature of the water stored in the tank is provided, and the control unit detects that the temperature detected by the water temperature sensor during the ice making operation is higher than 0° C. and is equal to or lower than a predetermined temperature. In such a case, the rotation speed of the pump motor may be reduced, and after a predetermined time has elapsed, the rotation speed of the pump motor may be increased.

In the ice making operation, ice making water that has passed through the ice making section is stored in the tank, so the water temperature in the tank follows the temperature of the ice making water in the ice making section. When the water temperature in the tank is below a predetermined temperature (higher than 0°C) (when the ice-making water is sufficiently cold), if the rotation speed of the pump motor is reduced, the flow rate of the ice-making water in the ice-making section will decrease. As the temperature of the section further decreases, seed ice is more likely to be produced in the ice making section. When the seed ice is generated, ice grows with the seed ice as a nucleus. If there is ice in the ice-making unit, the heat exchange efficiency in the ice-making unit is lowered, making it difficult to cool the ice-making water, making it difficult for overcooling to occur. For this reason, the rotation speed of the pump motor is reduced, and after seed ice is formed after a predetermined period of time has elapsed, the rotation speed of the pump motor is increased, thereby suppressing the occurrence of cotton ice and making ice. can be done faster.

Further, the pump motor is a DC motor, and the control unit controls the water circulation between the tank and the ice making unit to be normal when the rotational speed of the pump motor is equal to or lower than a predetermined rotational speed. It can be determined that it has not been performed in When scale deposits on the water circulation path between the tank and the ice making unit, the water circulation is hindered, and the load acting on the pump motor increases, resulting in a decrease in the rotational speed of the pump motor. Therefore, the control section can determine that the water circulation between the tank and the ice making section is not normally performed when the rotation speed becomes equal to or lower than the predetermined rotation speed.

Further, the pump motor is a DC motor, and the control unit controls the water circulation between the tank and the ice making unit to be normal when the current value of the pump motor is equal to or higher than a predetermined current value. It can be determined that it has not been performed in When scale deposits on the water circulation path between the tank and the ice making unit, the water circulation is hindered and the load acting on the pump motor increases, resulting in an increase in the current of the pump motor. Therefore, when the current value of the pump motor is equal to or higher than the predetermined current value, the control section can determine that water is not circulating normally between the tank and the ice making section.

Further, a water level sensor capable of measuring the level of water stored in the tank is provided, the ice-making unit includes an ice-making plate having an ice-making surface on which water flows down, and the tank is positioned below the ice-making plate. wherein the controller gradually reduces the rotation speed of the pump motor as the water level measured by the water level sensor decreases during the ice making operation. .

In the above configuration, the water level in the tank decreases as the ice on the ice making surface grows (increases). In addition, in the course of the water flowing down the ice making surface, the water may be splashed by the ice on the ice making surface and splashed. Therefore, by gradually lowering the rotational speed of the pump motor as the water level decreases, the amount of splashed water can be reduced, and the water can be returned to the tank more reliably. Also, by lowering the rotation speed of the pump motor, the amount of water in the circulation path between the tank and the ice making plate can be reduced. Since the water in the circulation path is not used for ice making, water can be saved by reducing the amount of such water.

Further, the control unit is configured to execute a cleaning operation in which water is circulated between the tank and the ice making unit by operating the pump motor while the cooling device is stopped. Further, the process of decreasing 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. By repeating increasing and decreasing the rotation speed of the pump motor in the washing operation, the water can be pulsated in the circulation path, and the water circulation path can be washed more efficiently.

a pipe connecting the ice-making unit and the pump; a drain pipe drawn from an intermediate portion of the pipe for draining water in the tank to the outside; a drain valve opening and closing the drain pipe; The ice making unit is arranged at a position higher than the pump, and the control unit operates the pump motor in a state where the drain valve is open, so that the inside of the tank is discharged through the drain pipe. A water discharge operation for discharging water to the outside is executed, and in the water discharge operation, the pump motor is operated so that the height of the water pumped up by the pump is between the ice making section and the intermediate section. The rotation speed can be controlled.

By operating the pump, in addition to supplying water to the ice making section, it is possible to drain the water in the tank. The height (head) of the water pumped up by the pump in the drainage operation is set to a height between the ice-making section and the intermediate section, so the water in the tank can be prevented from going to the ice-making section. , the water can be reliably drained.

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 drain pipe for draining the water in the tank to the outside, and a drain valve for opening and closing the drain pipe, and the controller opens the water supply valve to allow the tank to drain the external water source. and a first process of supplying water from the ice-making unit, which is executed after the first process, and circulates water between the tank and the ice-making unit by operating the pump motor while the cooling device is stopped. a second process; and a third process, which is executed after the second process and drains the water in the tank to the outside through the drain pipe by operating the pump motor with the drain valve open. , may be performed periodically.

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 period of time, the temperature of the water remaining in the water circulation path between the tank and the ice making unit (hereinafter simply referred to as the circulation path) rises, causing bacteria to grow. It is conceivable that it may become easier to reproduce. By executing the first to third processes, the water remaining in the circulation path can be washed with the supplied water and drained. By periodically executing such first to third processes, the inside of the circulation path can be maintained in a cleaner state even if the state in which the ice making operation is not performed continues for a long period of time.

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

Further, a UV sterilization device that sterilizes the water in the tank by irradiating the water in the tank with ultraviolet rays is provided, and the control unit operates the UV sterilization device after executing the third process. , a fourth process of sterilizing the water in the tank can be executed. The water in the tank that could not be drained by the third treatment can be sterilized by the UV sterilizer. This will keep the inside of the tank cleaner.

ADVANTAGE OF THE INVENTION According to this invention, the ice-making machine which can increase/decrease the amount of circulation of the water between a tank and an ice-making part can be provided.

Illustration showing an ice machine Perspective view showing the ice making section Cross-sectional view showing an enlarged area near the storage pipe in the tank Block diagram showing the electrical configuration of the ice maker 4 is a flow chart showing processing of a control unit related to ice making operation; 4 is a flow chart showing processing of a control unit related to deicing operation; Flowchart showing processing of the control unit related to the cleaning operation The figure which shows the ice-making machine of a comparative example Flowchart showing processing of the control unit related to residual water treatment operation Timing chart showing the timing at which the residual water treatment operation is executed Flowchart showing processing of the control unit when the power is turned on

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

The ice making machine 10 also has an ice making unit temperature sensor 16 capable of detecting the temperature of the ice making unit 11 (more specifically, the ice making plate 12) and the temperature of the water stored in the tank 13. A water temperature sensor 17, a pipe 18 connecting the ice making section 11 and the pump 15, a drain pipe 20 drawn from an intermediate portion 19 of the pipe 18 for draining the water in the tank 13 to the outside, and a drain pipe 20. A drain valve 21 that opens and closes, a distance sensor 22 that is arranged above the water stored in the tank 13 and is capable of measuring the distance to the water surface 58 of the water stored in the tank 13, and the water stored in the ice storage tank 14. An ice storage unit side distance sensor 23 (ice storage tank side distance sensor);

The ice making unit 11 includes a plurality of ice making plates 12 , a water spray pipe 24 and a water spray guide 25 . The ice making plate 12 is provided in a vertical posture. A meandering evaporator tube 44 (a part of the cooling device 40) is provided between a pair of the ice making plates 12, 12 arranged to face each other. As shown in FIG. 2, the ice making plate 12 has a plurality of vertically extending ice making surfaces 12A and a plurality of vertically extending ridges 12B. A plurality of ice making surfaces 12A are arranged in a horizontal direction, and adjacent ice making surfaces 12A are partitioned by ridges 12B. The ice making surface 12</b>A is formed by the surface of the ice making plate 12 opposite to the evaporating tube 44 . A sprinkler pipe 24 (sprinkler) 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 watered on each ice making surface 12A by the watering pipe 24 . Ice-making water sprayed from the water spray pipe 24 is guided to each ice-making surface 12A by a water-spraying guide 25, and then flows down each ice-making surface 12A.

The cooling device 40 includes a compressor 41, a condenser 42, an expansion valve 43, an evaporation pipe 44, and a fan 46, as shown in FIG. The compressor 41, the condenser 42, the expansion valve 43, and the evaporator pipe 44 are connected by a refrigerant pipe 45 containing refrigerant. The compressor 41 compresses refrigerant gas. The condenser 42 cools and liquefies the compressed refrigerant gas by blowing air from the fan 46 . The expansion valve 43 expands the liquefied refrigerant. The evaporator pipe 44 (evaporator) evaporates the liquefied refrigerant expanded by the expansion valve 43 to cool the ice making plate 12 . Thus, the compressor 41 , the condenser 42 , the expansion valve 43 , the evaporating pipe 44 and the refrigerant pipe 45 constitute a refrigerant circulation cycle (refrigerating circuit) for cooling the ice making plate 12 . The cooling device 40 also includes a dryer 47 for removing moisture mixed in the refrigeration circuit. The ice making unit temperature sensor 16 is provided in the refrigerant pipe 45 near the exit of the evaporating pipe 44 and is capable of detecting the temperature of the ice making plate 12 . A thermistor, for example, can be used as the ice-making unit temperature sensor 16, but it is not limited to this.

The cooling device 40 also includes a bypass pipe 49 for supplying the refrigerant gas (hot gas) compressed by the compressor 41 to the evaporating pipe 44, and a hot gas valve 50 which is an electromagnetic valve provided in the bypass pipe 49. , provided. By opening the hot gas valve 50 , the refrigerant gas (hot gas) can be supplied from the compressor 41 to the evaporating pipe 44 to heat the evaporating pipe 44 . That is, the cooling device 40 has a function as a heating device that heats the evaporation pipe 44 .

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

A water supply pipe 52 (spray pipe on the water supply side) is provided between the pair of ice making plates 12 , 12 . The ice maker 10 also 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 . Thus, by opening the water supply valve 30, the tap water is supplied to the tank 13 after flowing down the back surface of the ice making plate 12 (the surface opposite to the ice making surface 12A). Moreover, of the ice-making water that flows down the ice-making surface 12A, the water that has not frozen is stored in the tank 13 . That is, the tank 13 is configured such that, of the ice-making water supplied to the ice-making section 11 , the water that has not frozen is stored in the tank 13 . Thus, by operating the pump 15, the ice making water can be circulated between the tank 13 and the ice making section 11. As shown in FIG. In this specification, ice-making water is not limited to water used for ice-making, and includes water circulating between tank 13 and ice-making unit 11 .

In addition, when the water in the tank 13 exceeds a predetermined overflow water level L1 (see the two-dot chain line in FIG. 3), the tank 13 can drain the water exceeding the overflow water level L1 to the outside of the tank 13. configuration. More specifically, in the tank 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 water overflowing from the water storage space A1. The tank main body 26 has a standing wall 32 that partitions the overflow space A2 and the water storage space A1. The height of the upper end of the standing wall portion 32 matches the overflow water level L1 of the tank 13 . As a result, when the water level in the water storage space A1 exceeds the height of the upper end of the vertical wall portion 32, the water exceeds the upper end of the vertical wall portion 32 and flows into the overflow space A2 to be drained. Note that the overflow space A2 may be configured by an overflow pipe provided in the tank 13 .

The pump 15 has a pump motor 33 whose rotational speed can be changed, and can supply the 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) whose rotational speed can be changed. 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

Also, the ice making unit 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 discharging the water in the tank 13 to the outside is provided in an 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 .
The ice making surface 12A side of the ice making section 11 can be washed by operating the pump 15 with clean water or detergent in the tank 13. - 特許庁Also, the water supply pipe 29 and the pipe 18 are connected via a part of the drain pipe 20 and the valve 34 . As a result, when the pump 15 is operated with the water supply valve 30 and the water discharge valve 21 closed, the water in the tank 13 can be supplied to the back surface of the ice making plate 12 through the water supply pipe 52. can be washed.

The distance sensor 22 is arranged above the water stored in the tank 13, and measures the distance to the surface of the water stored in the tank 13 by irradiating ultrasonic waves toward the surface of the water in the tank 13. It is an ultrasonic sensor that can More specifically, the distance sensor 22 includes an irradiation unit that emits ultrasonic waves and a reception unit that receives ultrasonic waves reflected by the surface of the water in the tank 13. The ultrasonic waves emitted from the irradiation unit are reflected It is possible to measure the distance from the distance sensor 22 to the surface of the water based on the time it takes to return to the receiver. 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.

The distance sensor 22 is housed in a housing tube 35 provided in a lid 27 covering the tank 13, as shown in FIG. By housing the distance sensor 22 in the housing tube 35, it is possible to reduce measurement errors of the distance sensor 22 due to ambient temperature changes. The housing tube 35 is a circular tube that is elongated in the vertical direction, and is arranged so as to pass through the lid body 27 . Further, the storage pipe 35 is opened downward, and its lower end (open end) faces the bottom surface 13A of the tank 13 with a small gap therebetween. Therefore, in the tank 13 , the water level inside the accommodation pipe 35 is the same as the water level outside the accommodation pipe 35 . A notch 36 is formed at the open end (lower end) of the housing tube 35 . By providing such a notch 36, it is possible to prevent the water from rippling inside the housing pipe 35, and it is possible to further improve the water level measurement accuracy.

Further, an air hole 37 is formed at a position higher than the cover 27 in the housing pipe 35 so as to communicate the inside of the housing pipe 35 with the outside (the outside of the tank 13). The air hole 37 is arranged at a position higher than the lid 27 . When the water level inside the accommodation pipe 35 rises, the air inside the accommodation pipe 35 is discharged to the outside through the air holes 37 by the amount corresponding to the rise in the water level.

The distance sensor 22 is provided on the ceiling portion 35A of the housing tube 35. As shown in FIG. That is, the distance sensor 22 is arranged at a position higher than the lid body 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 emitted to the bottom surface 13A of the tank 13 is substantially equal to the cross-sectional area of the storage pipe 35. As a result, it is possible to prevent the ultrasonic waves emitted from the distance sensor 22 from being reflected on the inner surface of the housing tube 35 . The directivity angle of the ultrasonic waves emitted from the distance sensor 22 is set, for example, within a range of 5 degrees to 10 degrees, but is not limited to this.

In the housing tube 35, a first sound absorbing material 38 is provided so as to surround the distance sensor 22 from all sides 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 rubber, and the second sound absorbing material 39 is made of foam. By surrounding the distance sensor 22 with the first sound absorbing material 38 and the second sound absorbing material 39, the situation that the distance sensor 22 receives external noise can be suppressed, and the measurement accuracy of the distance sensor 22 can be further improved. can be done.

A water temperature sensor 17 (see FIG. 1) capable of detecting the temperature of 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 provided in contact with the water in the tank 13 . A thermistor, for example, can be used as the water temperature sensor 17, but it is not limited to this.

The ice storage tank 14 stores the ice made by the ice making section 11, and is arranged below the ice making section 11 as shown in FIG. there is The user takes out the ice that has been made from the ice storage tank 14 and uses it. The drainboard 28 described above constitutes a part of the ice discharge pipe 51 . The drainboard 28 is provided in a posture inclined downward toward the ice inlet 14A in the ice storage tank 14 . As a result, the ice falling on the drainboard 28 is sent toward the inlet 14A. The ice storage section side distance sensor 23 is an ultrasonic sensor provided on the upper wall section 14B that constitutes the ice storage tank 14. The ice storage section side distance sensor 23 emits ultrasonic waves to the upper surface 14D of the ice stored in the ice storage tank 14, thereby removing the ice. It is configured to be able to measure the distance to the upper surface 14D of the .

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, when the amount of ice in the ice storage tank 14 increases, the top surface of the ice rises, so the distance from the ice storage unit side distance sensor 23 to the top surface of the ice decreases, and the amount of ice in the ice storage tank 14 decreases. Then, the upper surface of the ice becomes lower, so the distance from the ice storage unit side distance sensor 23 to the upper surface of the ice increases.

Next, the electrical configuration of the ice making machine 10 will be described. The ice maker 10 includes a control section 80 as shown in FIG. The control unit 80 includes the cooling device 40 (more specifically, the compressor 41, the fan 46, and the hot gas valve 50), the distance sensor 22, the ice storage unit side distance sensor 23, the pump motor 33, the ice making unit temperature sensor 16, the water temperature The sensor 17, the water supply valve 30, the water discharge valve 21, the valve 34, the timer 53 (timer), the memory 54, and the UV sterilizer 70 are electrically connected. The ice making machine 10 also includes an operation unit 55 including switches that can be operated by the user, and a display unit 56 (for example, a liquid crystal panel) that can display error messages and the like. In other words, the display unit 56 is a notification unit that can notify the operator of an error. The operation section 55 and the display section 56 are electrically connected to the control section 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 and a RAM. By executing the program stored in the storage unit 54, the control unit 80 controls the operation of the operation unit 55 by the user, each sensor (distance sensor 22, ice storage side distance sensor 23, ice making unit temperature sensor 16, water temperature sensor 17) based on the measured value and the time measurement by the time measurement unit 53, it is possible to control the operation of each device (cooling device 40, pump motor 33, water supply valve 30, drainage valve 21, valve 34, display unit 56). It's becoming In addition, the storage unit 54 stores each setting value related to the operation of the ice making machine. Further, the control unit 80 can refer to the rotation speed and current value of the pump motor 33 .

The control unit 80 is capable of executing an ice making operation, a deicing operation and a cleaning operation. The ice making operation is an operation in which ice is made in the ice making unit 11 by operating the pump motor 33 while operating the cooling device 40 to cool the ice making plate 12 . In the deicing operation, ice is deiced 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. is driving. The cleaning operation is an operation in which water is circulated between the tank 13 and the ice making unit 11 by operating the pump motor 33 while the cooling device 40 is stopped, and the circulation path of the ice making water is cleaned. Yes (details below).

Also, the control unit 80 can control the rotation speed of the pump motor 33 . In the present embodiment, as the rotational speed of the pump motor 33, five stages of rotational speeds, ie, high speed V1, medium speed V2, low speed V3, washing high speed V4A, and washing low speed V4B, are set. Although V1>V2>V3, V4A>V1, and V4A>V4B, the value of each rotational speed can be set appropriately. Further, in the following description, "the controller 80 opening the water supply valve 30 to supply tap water into the tank 13" may be referred to as "water supply".

Next, 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 using the operation unit 55 to perform an operation for starting the ice making operation. Before performing the ice making operation, the control unit 80 executes water supply processing for supplying water to the tank 13 . In the water supply process, the controller 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 reaches a preset operation start distance K2, in other words, when the water level in the tank 13 reaches the operation start water level L2. and start the ice making operation.

That is, the operation start water level L2 is the water surface level corresponding to the operation start distance K2. The operation start distance K2 (operation start water level L2) can be set as appropriate. For example, as shown in FIG. 3, the operation start distance K2 is set such that the operation start water level L2 is lower than the overflow water level L1. Also, 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 ice making plate 12 is cooled by the control unit 80 operating the cooling device 40 (step S1). In the ice making operation, the control unit 80 also controls the rotation speed of the pump motor 33 based on the state of the ice on the ice making surface 12A. Immediately after starting the ice making operation, the control unit 80 operates the pump motor 33 at the high speed V1 (step S2). When the pump motor 33 is operated, the ice-making water circulates between the tank 13 and the ice-making section 11, and is cooled while flowing down the cooled ice-making surface 12A. Immediately after starting the ice-making operation, the ice-making water in the tank 13 is at a temperature close to that of tap water (for example, 20°C), and it is necessary to cool the ice-making water to 0°C in order to freeze it. By operating the pump motor 33 at the high speed V1 immediately after starting the ice-making operation, the amount of ice-making water circulating between the tank 13 and the ice-making section 11 can be increased, so that the ice-making water can be efficiently cooled. .

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

The operation stop distance K4 is, as shown in FIG. 3, the distance from the operation start water level L2 to the water surface at a water level (operation stop water level L4) lower than the operation start water level L2 by a predetermined value K3. Also, the predetermined value K3 corresponds to the amount of ice to be made in the ice making operation. In this embodiment, the predetermined value K3 can be set by the user operating the operation unit 55. FIG. In other words, in this embodiment, by setting the predetermined value K3, it is possible to set the operation stop water level L4 and thus the amount of ice (the size of each ice 57) made in the ice making operation.

When the temperature of the ice making water drops, the heat exchange between the ice making water and the ice making plate 12 is suppressed, so the temperature of the ice making plate 12 drops. After the water level in the tank 13 reaches the operation start water level L2 (after step S4), the control unit 80 controls the pump motor 33 to is set to low speed V3 (step S6). The following predetermined temperatures C1 and C2 are values greater than 0° C. and values near 0° C., and can be set as appropriate. It is preferable that the predetermined temperature C1 is set, for example, within the range of 1.degree. C. to 5.degree. C., and the predetermined temperature C2 is set, for example, within the range of 2.degree. In other words, the control unit 80 sets the pump motor to the 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 water temperature sensor 17 for measuring water temperature of tank 13≦predetermined temperature C1 (for example, 2.5° C.)
Condition FA2: Temperature detected by ice-making unit 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 the temperature of the ice making surface 12A is further lowered. As a result, ice nuclei (seed ice) are likely to be formed at locations on the ice making surface 12A corresponding to the evaporating tubes 44 (locations on 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 ice-making water can be prevented from being supercooled, and the occurrence of cotton ice 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 the middle speed V2 (step S8). The predetermined temperature C3 below is a temperature higher than 0° C. and lower than the predetermined temperature C2.
Condition FA3: The state of temperature detected by the ice-making unit temperature sensor 16≦predetermined temperature C3 (eg, 1° C.) continued for a predetermined time T3 (eg, 120 seconds).
Further, instead of the condition FA3, the control unit 80 may set the pump motor 33 to the medium speed V2 when it detects that seed ice is generated on the ice making surface 12A. The detection of seed ice can be realized, for example, by photographing the ice making surface 12A with a camera and analyzing the photographed image.

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

In other words, the control unit 80 performs processing to increase the rotation speed of the pump motor 33 (to the middle speed V2) after a predetermined time has elapsed after setting the pump motor 33 to the low speed V3. After the seed ice is generated on the ice making surface 12A, the ice making water freezes while flowing down the surface of the seed ice. As a result, half-moon shaped ice 57 (see FIG. 1) protruding from the ice making surface 12A grows as time elapses. When ice 57 is generated on the ice making surface 12A, heat exchange between the ice making surface 12A and the ice making water is suppressed by the ice 57, so the cooling speed of the ice making water decreases. For this reason, after the seed ice is generated, it is difficult to generate flocculent ice even if the rotation speed of the pump motor 33 is increased.

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 rotation speed reduction processing (step S9). In the rotation speed reduction process, 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), the rotation speed of the pump motor 33 is gradually decreased. As the ice on the ice-making surface 12A becomes larger, the ice-making water supplied to the ice-making plate 12 is repelled by the ice and becomes more likely to scatter. Since the scattered ice-making water does not return to the tank 13, the water used for ice-making is reduced and the size of the ice becomes smaller than desired. Therefore, by gradually lowering the rotational speed of the pump motor 33 as the ice grows, the circulation amount of the ice making water can be reduced, and the scattering of the ice making water can be suppressed. Note that in the rotation speed reduction process, the rotation speed of the pump motor 33 may be lowered continuously or stepwise.

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 when the distance to the water surface detected by the distance sensor 22 is greater than the operation start distance K2). When the distance K4 is reached), the pump motor 33 is stopped to stop the ice making operation and shift to the deicing operation. Instead of step S10, the control unit 80 determines that "the state in which the water level in the tank 13 is equal to or lower than the operation stop water level L4" has continued for a predetermined time T9 (for example, 20 seconds) (the water level in the tank 13 is On the condition that the water level is stabilized at L4 or lower), the pump motor 33 may be stopped to stop the ice making operation and shift to the deicing operation. In this way, the influence of the water level change due to the waving of the water surface in the tank 13 can be suppressed, so that the size of the ice to be made can be 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 performed normally, and the display unit At 56, an error message is displayed to inform the user that "water is not circulated normally (error)". 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 the error (water is not circulated 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

It should be noted that the reason why the water circulation between the tank 13 and the ice-making unit 11 is not normally performed may be the deposition of scale in the circulation path of the ice-making water. In the circulation path, scale is particularly likely to deposit at locations where the flow velocity is slow (the end of the water spray pipe 24, the end of the water spray guide 25, etc.). Therefore, the control unit 80 may execute the cleaning operation as the error handling process when the condition FE1 or the condition FE2 is satisfied. Further, the control unit 80 may stop the operation of the ice making machine 10 as error handling processing when the condition FE1 or the condition FE2 is satisfied.

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, for example, the control unit 80 displays an error message on the display unit 56 to notify the user that the water level of the tank is abnormal.
Condition FE3: Distance to water surface measured by distance sensor 22≧first abnormal distance K5
Condition FE4: Distance to water surface measured by distance sensor 22≦second abnormal distance K6
Note that the control unit 80 may execute error notification processing for notifying an error when the condition FE3 or the condition FE4 is satisfied for a predetermined time during the deicing operation or the cleaning 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 driving start distance K2. For this reason, "the fact that the distance to the water surface measured by the distance sensor 22 is greater than or equal to the first abnormal distance K5 corresponds to a significant drop in the water level in the tank 13. Note that the first abnormal distance K5 is, for example, a value corresponding to the safe water level L5 of the pump 15. The safe water level L5 is a water level below which the discharge amount of the pump 15 becomes unstable. The fact that the distance to the water surface measured by the sensor 22 is equal to or less than the second abnormal distance K6 corresponds to a significant increase in the water level in the tank 13. As shown in FIG. The abnormal distance K6 is a value corresponding to the water level L6 which is higher than the overflow water level L1.Therefore, the cause of satisfying the above condition FE4 is that the tank 13 is not properly drained through the overflow space A2. Alternatively, the distance sensor 22 may not be installed at a proper position, and the water level in the tank 13 may not be measured correctly.

Next, processing of the control unit 80 in the deicing operation will be described. In the deicing operation, as shown in FIG. 6, the controller 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. Drainage operation (drainage treatment) is executed (step S21). When the water level in the tank 13 drops as the water is drained, and the distance detected by the distance sensor 22 reaches a distance corresponding to the preset bottom surface 13A of the tank 13 (the height of the bottom surface 13A is detected), the control The unit 80 determines that the water discharge is completed, stops the pump motor 33, closes the water discharge valve 21, and stops the water discharge operation.

In the ice-making operation of the flow-down ice-making machine, the impurities contained in the water in the tank 13 are hard to freeze on the ice-making surface 12A and are collected in the tank 13. Therefore, the ice 57 is in a state with extremely few impurities (ultra-pure water ). In other words, immediately after the ice-making operation is completed, the water in the tank 13 is concentrated water with a high concentration of impurities. Such concentrated water causes scale to occur in the circulation path. Therefore, it is more preferable to drain the concentrated water by performing the water discharge operation immediately after the ice making operation as described above. In the water discharge operation, the control unit 80 controls the rotation speed of the pump motor 33 (at least higher than the low speed V3) so that the height of the water pumped up by the pump 15 is between the ice making unit 11 and the intermediate unit 19. low speed). As a result, the water in the tank 13 to be drained can be prevented from going to the ice making section 11, and the water can be drained more reliably.

Next, the controller 80 stops the fan 46 and opens the hot gas valve 50 (step S22). As a result, refrigerant gas (hot gas) is supplied from the compressor 41 to the evaporator tube 44, and the evaporator tube 44 (and thus the ice making 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 making plate 12 through the water supply pipe 52 (step S23). As a result, the ice making plate 12 is heated by the tap water and the hot gas, and the portion of the ice 57 in contact with the ice making surface 12A melts, so that the ice 57 is peeled off (de-iced) from the ice making surface 12A. The deiced ice falls on the drainboard 28 and is stored in the ice storage tank 14.例文帳に追加Moreover, the water level in the tank 13 rises because the tap water flowing down the back surface of the ice making plate 12 falls into the tank 13 . When the water level in the tank 13 rises to the operation start water level 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 The water supply valve is closed to stop water supply (step S25).

When the ice 57 is deiced, the deiced water in which a portion of the ice 57 (the contact portion with the ice making surface 12A) is melted is collected in the tank 13 . Since such deiced water contains few impurities, it is preferable to reuse it for making ice 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 prevent the deicing water from overflowing and being drained.

After that, when the temperature of the ice making 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 the medium speed V2 (step S27). For example, in step S27, the pump motor 33 is operated at the medium speed V2 for a predetermined time T5 (for example, 15 seconds) and then stopped. After operating for a predetermined time T7 (for example, 15 seconds), it is stopped. In this manner, the deicing of the ice can be promoted by flowing the ice-making water to the ice-making surface 12A while the temperature of the ice-making plate 12 has risen to some extent.
Condition FB1: detected temperature of ice making unit temperature sensor 16≧predetermined temperature C4 (for example, 4° C.)
When the portion of the ice 57 that contacts the ice making surface 12A is melted, the surface tension of the water between the ice 57 and the ice making surface 12A makes it difficult for the ice 57 to separate from the ice making surface 12A. Therefore, as described above, after the portion of the ice 57 in contact with the ice making surface 12A melts, the pump motor 33 is operated to flow the ice making water onto the ice making surface 12A, thereby knocking the ice 57 off with the force of the water. De-icing can be promoted by doing so. However, when refrigerant gas (hot gas) is supplied from the compressor 41 to the evaporating pipe 44, the inlet side of the evaporating pipe 44 (the side close to the hot gas valve 50, corresponding to the upper portion of the ice making plate 12) is the outlet of the evaporating pipe 44. It warms up more easily than the side (the side of the ice making part temperature sensor 16, which corresponds to 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 faster at the contact portion with the ice making surface 12A. For this reason, in this embodiment, the pump motor 33 is first operated at the medium speed V2 for a predetermined time T5 to remove the ice 57 above the ice making surface 12A (approximately the upper half of the ice making surface 12A), which is relatively easy to melt. make ice After that, by allowing a predetermined time T6 to elapse, the portion of the ice 57 in contact with the ice making surface 12A at the bottom of the ice making surface 12A melts. 57 is de-iced.

Then, after the following condition FB2 is satisfied ("YES" in step S28), the control unit 80, when a predetermined time T8 (for example, 60 seconds) elapses ("YES" in step S29), the entire surface of the ice making surface 12A is ice is deiced, the deicing operation is stopped, and the ice making operation is started. Although the predetermined temperatures C4 and C5 can be set appropriately, the predetermined temperatures C4 and C5 are set at temperatures 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 unit temperature sensor 16≧predetermined temperature C5 (for example, 9° C.)

Note that the control unit 80 continues until the distance to the upper surface 14D of ice (corresponding to the amount of ice stored in the ice storage tank) measured by the ice storage unit side distance sensor 23 reaches a predetermined distance K7 ( The ice making operation and the deicing operation are repeatedly performed 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 the ice making operation is performed for the second and subsequent times, the control unit 80 may omit the water supply process (the process of supplying tap water to the operation start water level L2) performed before the ice making operation.

Further, the control unit 80 executes the cleaning operation after the deicing operation on condition that the cycle of the ice making operation and the deicing operation has been performed a predetermined number of times (for example, 20 times). Next, processing of the control unit 80 in the cleaning operation will be described. In the cleaning operation, as shown in FIG. 7, the controller 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, When the water level reaches a predetermined level (for example, overflow water level L1) ("YES" in step S43), the water supply valve is closed (step S44).

Next, while the cooling device 40 is stopped, the control unit 80 operates the pump motor 33 and opens the valve 34 to cause water to flow between the tank 13 and the ice making unit 11 (front and back surfaces of the ice making plate 12). circulate. In the cleaning operation, the controller 80 alternately repeats the process of decreasing the rotational speed of the pump motor 33 and the process of increasing the rotational speed of the pump motor 33 . Specifically, the control unit 80 performs a first operation process in which the pump motor 33 is operated at the cleaning high speed V4A, which is higher than the high speed V1, for a predetermined time (step S45), and then operates at the cleaning low speed V4B. A second operation process is performed to operate for a predetermined time (step S46). The control unit 80 alternately and repeatedly executes the first operation process and the second operation process. 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, closes the valve 34, and 33 is operated to execute a drainage operation (drainage treatment) for draining the water in the tank 13 (step S48). This stops the cleaning operation. Note that the control unit 80 shifts to the ice making operation after the washing operation is stopped.

Further, in the above-described embodiment, the cleaning operation is performed on the condition that the cycle of the ice making operation and the deicing operation is performed a predetermined number of times, but the present invention is not limited to this. A sensor measures the concentration of impurities contained in the water in the tank 13, and when the concentration of impurities exceeds a predetermined value, the control unit 80 may execute the cleaning operation after the deicing operation. good. Note that the higher the concentration of impurities in water, the higher the electrical conductivity. Therefore, in this embodiment, an electrical conductivity sensor capable of measuring electrical conductivity may be provided. Such an electrical conductivity sensor is electrically connected to the control unit 80. The electrical conductivity sensor measures the electrical conductivity of water. The cleaning operation may be executed when (the impurity concentration is equal to or higher than a predetermined value). The water temperature sensor 17 is configured by, for example, housing a thermistor in a metal case 17A (outer shell of the water temperature sensor 17, see FIG. 3). When the water temperature sensor 17 having such a configuration is used, an electrode 48 may be provided so as to be in contact with the water in the tank 13, as indicated by the chain double-dashed line in FIG. The electrode 48 is spaced apart from the case 17A, and the electrode 48 and the case 17A are electrically connected to the controller 80 . By energizing both the electrode 48 and the case 17A, the control unit 80 causes an electric current to flow through the water between the electrode 48 and the case 17A, and measures the electric resistance of the water. Conductivity can be measured. That is, one of the pair of electrodes constituting the electrical conductivity sensor (for example, the positive electrode) may be configured by the electrode 48, and the other electrode (eg, the negative electrode) may be configured by the case 17A.

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

In this embodiment, even when the water is drained by the pump 15, the water is partially filled in the water circulation path between the tank 13 and the ice making unit 11 (including the tank 13 and the ice making unit 11). There are concerns about what remains. In the following description, the water remaining in the circulation path without being completely drained is referred to as residual water. An example of a location where residual water is generated is the bottom of the tank 13, for example. 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. A gap must be provided between the bottom surface 13E of 13D and the lower end of the pump 15. Due to such circumstances, for example, a small amount of residual water that cannot be sucked by the pump 15 exists in the bottom of the tank 13 (recess 13D). When the ice making operation is not executed for a long time, it is assumed that the water temperature of the residual water will rise. When the water temperature of the residual water rises, there is a concern that bacteria may propagate.

Therefore, in the present embodiment, the control unit 80 executes residual water treatment operation for treating residual water. In the residual water treatment operation, as shown in FIG. 9, the following first to fourth treatments are executed in order. In the first process (residual water dilution process, step S51), the control unit 80 opens the water supply valve 30 to supply water (tap water) from the water pipe 31 to the tank 13 . As a result, the water (residual water) in the tank 13 is diluted with the supplied water. In the first process, after the water level in the tank 13 measured by the distance sensor 22 reaches the overflow water level L1 (see FIG. 3), the control unit 80 continues water supply for a predetermined period of time. close. As a result, part of the diluted water in the 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 causes the pump motor 33 to operate for a predetermined time while the cooling device 40 is stopped and the valve 34 is opened. to circulate water between the tank 13 and the ice making section 11 (including the front and back surfaces of the ice making plate 12). As a result, residual water remaining in the circulation path other than the tank 13 can be sent to the tank 13 by flushing it with the circulating water.

In the third process (residual water drainage process, step S53) executed after the second process, the controller 80 operates the pump motor 33 with the drain 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. - 特許庁When the water level in the tank 13 drops as the water is drained, and the distance detected by the distance sensor 22 reaches a distance corresponding to the preset bottom surface 13A of the tank 13 (the height of the bottom surface 13A is detected), the control The unit 80 determines that the water discharge is completed, stops the pump motor 33, closes the water discharge 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 up by the pump 15 is between the ice making unit 11 and the intermediate unit 19 . As a result, the water in the tank 13 can be prevented from going to the ice making section 11, and the water can be drained more reliably.

In the fourth process (sterilization process, step S54) executed after the third process, the control unit 80 causes the UV sterilizer 70 to operate for a predetermined period of time so that the water in the tank 13 (the water in the tank 13 is water) is sterilized.

As shown in FIG. 10, the control unit 80 sets the predetermined time T11 (for example, 4 hours) in a state in which neither the ice-making operation nor the de-icing operation is performed (in other words, a state in which the cooling device 40 is stopped). The residual water treatment operation (first treatment, second treatment, third treatment, fourth treatment, steps S51 to S54) is executed every time the time elapses. In other words, the control unit 80 periodically executes the residual water treatment operation when the ice making operation and the deicing operation are not being executed.

Further, as shown in FIG. 11, the control unit 80 performs the residual water treatment operation (first to fourth process) is executed (step S62). The user can switch the power of the ice making machine 10 between ON and OFF states by operating a power switch included in the operation unit 55, for example.

Next, the effects of this embodiment will be described. The ice making machine 10 of this embodiment includes an ice making unit 11 that makes ice by freezing water, a cooling device 40 that cools the ice making unit 11, a tank 13 that stores water, and a rotation speed that can be changed. A pump 15 having a pump motor 33, the pump 15 being capable of supplying water in the tank 13 to the ice making unit 11 as the pump motor 33 is driven; Of the water supplied to the ice making unit 11, the water that has not frozen is stored in the tank 13, and the control unit 80 operates the cooling device 40 and the pump motor 33 so that An ice-making operation for making ice is executed, and the rotational speed of the pump motor 33 is controlled during the ice-making operation.

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 circulated between the tank 13 and the ice making section 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 rotational speed (high speed V1) to increase the circulation amount of the ice-making water. However, if the ice-making water is sufficiently cooled and a large amount of ice-making water continues to be circulated, the overcooling of the ice-making water may cause fluff ice to occur in the tank 13, which may hinder the circulation of the ice-making water. In the above configuration, the control unit 80 can reduce the rotational speed of the pump motor 33 (to low speed V3) during the ice making operation. The amount can be reduced, and the generation of cotton ice can be suppressed.

Also, an ice-making unit temperature sensor 16 capable of detecting the temperature of the ice-making unit 11 is provided. When the condition becomes below, the rotational speed of the pump motor 33 is decreased, and after a predetermined time has passed, processing is performed to increase the rotational speed of the pump motor 33 .

In the ice-making operation, ice-making water is cooled, and the temperature of ice-making section 11 is accordingly lowered. If the rotation speed of the pump/motor 33 is reduced when the temperature of the ice-making unit 11 is below a predetermined temperature (higher than 0° C.) (the ice-making water is sufficiently cooled), the flow rate of the ice-making water in the ice-making unit 11 decreases. As the temperature of the ice making unit 11 further drops, seed ice is likely to be generated in the ice making unit 11 . When the seed ice is generated, ice grows with the seed ice as a nucleus. If there is ice in the ice-making unit 11, the heat exchange efficiency in the ice-making unit 11 is lowered, so that the ice-making water is difficult to be cooled and supercooling is unlikely to occur. For this reason, the rotational speed of the pump motor 33 is reduced (to low speed V3), and after the seed ice is formed after a predetermined period of time has elapsed, the rotational speed of the pump motor 33 is increased (to medium speed V2). , the production of ice can be performed more quickly while suppressing the occurrence of cotton ice.

A water temperature sensor 17 capable of detecting the temperature of the water stored in the tank 13 is also provided, and the control unit 80 detects a predetermined temperature C1 higher than 0° C. detected by the water temperature sensor 17 during the ice making operation. When the condition becomes below, the rotational speed of the pump motor 33 is decreased, and after a predetermined time has passed, processing is performed to increase the rotational speed of the pump motor 33 .

During the ice making operation, ice making water that has passed through the ice making section 11 is stored in the tank 13 , so the water temperature in the tank 13 follows the temperature of the ice making water in the ice making section 11 . If the rotation speed of the pump motor 33 is reduced when the water temperature in the tank 13 is below a predetermined temperature (higher than 0° C.) (when the ice making water is sufficiently cooled), the flow rate of the ice making water in the ice making section 11 decreases. However, when the temperature of ice making unit 11 further decreases, seed ice is likely to be generated in ice making unit 11 . When the seed ice is generated, ice grows with the seed ice as a nucleus. If there is ice in the ice-making unit 11, the heat exchange efficiency in the ice-making unit 11 is lowered, so that the ice-making water is difficult to be cooled and supercooling is unlikely to occur. For this reason, the rotation speed of the pump motor 33 is reduced, and after the seed ice is formed after a predetermined period of time has passed, the rotation speed of the pump motor 33 is increased, thereby suppressing the generation of cotton ice and preventing the formation of ice. Manufacturing can be done faster.

Further, the pump motor 33 is a DC motor, and the control unit 80 controls the water circulation between the tank 13 and the ice making unit 11 to be normal when the rotational speed of the pump motor 33 becomes equal to or less than a predetermined rotational speed. It is determined that the When scale deposits on the water circulation path between the tank 13 and the ice making unit 11, the water circulation is hindered, and the load acting on the pump motor 33 increases, resulting in a decrease in the rotation speed of the pump motor 33. Therefore, the control unit 80 can determine that the circulation of water between the tank 13 and the ice making unit 11 is not performed normally when the rotation speed is equal to or lower than the predetermined rotation speed.

Further, the pump motor 33 is a DC motor, and the control unit 80 controls the water circulation between the tank 13 and the ice making unit 11 to be normal when the current value of the pump motor 33 exceeds a predetermined current value. It is determined that the When scale deposits on the water circulation path between the tank 13 and the ice making unit 11, the water circulation is hindered, and the load acting on the pump motor 33 increases, so the current of the pump motor 33 increases. Therefore, when the current value of the pump motor 33 is equal to or greater than a predetermined current value, the control unit 80 determines that the water circulation between the tank 13 and the ice making unit 11 is not performed normally. can be done.

Further, a distance sensor 22 (a water level sensor) capable of measuring the water level of water stored in the tank 13 is provided. is arranged below the ice making plate 12, and the controller 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. process.

In the above configuration, as the ice on the ice making surface 12A grows (increases), the water level in the tank 13 decreases. In addition, in the course of water flowing down the ice making surface 12A, the water may be splashed by the ice on the ice making surface 12A and splashed. Therefore, by gradually lowering the rotational speed of the pump motor 33 as the water level decreases, the amount of splashed water can be reduced, and the water can be returned to the tank 13 more reliably. Also, by reducing the rotation speed of the pump motor 33, the amount of water in the circulation path between the tank 13 and the ice making plate 12 can be reduced. Since the water in the circulation path is not used for ice making, water can be saved by reducing the amount of such water.

Further, the control unit 80 is configured to execute a washing operation in which water is circulated between the tank 13 and the ice making unit 11 by operating the pump motor 33 while the cooling device 40 is stopped. , the process of decreasing 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, water is circulated between the tank 13 and the ice making section 11, so that the water circulation path can be washed. In the washing operation, by repeatedly increasing and decreasing the rotation speed of the pump motor 33, the water can be pulsated in the circulation path, and dirt (scales, etc.) in the circulation path can be efficiently removed by the pressure of the water. Therefore, the water circulation path can be cleaned more efficiently.

Also, a pipe 18 connecting the ice-making unit 11 and the pump 15, a drain pipe 20 drawn from an intermediate portion 19 of the pipe 18 for draining the water in the tank 13 to the outside, and a drain pipe opening and closing the drain pipe 20. The ice-making unit 11 is arranged at a position higher than the pump 15, and the control unit 80 operates the pump motor 33 with the drain valve 21 open to open the drain pipe 20. In the water discharge operation, the water pumped up by the pump 15 is set to a height between the ice making section 11 and the intermediate section 19. It controls the rotation speed of the pump motor 33 . By operating the pump 15, in addition to supplying water to the ice making section 11, it is possible to drain the water in the tank 13. The height (head) of the water pumped up by the pump 15 in the water discharge operation is set to be between the ice making section 11 and the intermediate section 19, so that the water in the tank 13 reaches the ice making section 11. It is possible to suppress the situation to go to, and to reliably drain water.

Also, an ice making unit 11 that makes ice by freezing water, a cooling device 40 that cools the ice making unit 11, a tank 13 that can store the water supplied to the ice making unit 11, and a water that is stored in the tank 13. and a distance sensor 22 arranged above the water stored in the tank 13 and capable of measuring the distance to the water surface of the water stored in the tank 13 . As the water level in the tank 13 increases, 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. Assuming that the float switch 2 is used to detect the water level in the tank 13 as shown in the ice making machine 1 of the comparative example in FIG. ), the height of the float 3 changes due to adhesion of foreign matter such as scale to the float 3, and there is a concern that the water level cannot be accurately detected. Since the distance sensor 22 configured as described above can prevent contact with water, the water level can be detected more accurately.

Moreover, 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 ice making operation start water level is set to the water level L11, and the operation stop water level is set to the water level L12. It is conceivable to execute an ice-making operation. In this case, since the amount of ice to be made is determined by the difference between L11 and L12, the amount of ice to be made by the ice making operation will be the same each time.

Further, when the float switch is used, after the water level in the tank 13 reaches L11 with the water supply, water is supplied for a predetermined time, and the water in the tank 13 overflows from the upper end of the vertical wall portion 32 to the overflow space A2. Then, the water level L13 (overflow water level) at that time is set as the operation start water level, and the ice making operation is executed until the operation stop water level L12 is reached. Even in this case, since the amount of ice to be made is determined by the difference between L13 and L12, the amount of ice to be made is the same each time. Moreover, since the water in the tank 13 will overflow, it is not preferable from the viewpoint of saving water. In this 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 made 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 ultrasonic waves toward the water surface. According to the distance sensor 22 configured as described above, the water level 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 includes the pump motor 33 and is capable of supplying the water in the tank 13 to the ice making unit 11 as the pump motor 33 is driven; The water supplied to the ice making unit 11 is stored in the tank 13 without being frozen. Further, when the distance to the water surface detected by the distance sensor 22 reaches the preset operation start distance K2, the ice making operation is started and the distance The ice making operation is stopped when the distance to the water surface detected by the sensor 22 reaches an operation stop distance K4 that is longer than the operation start distance K2. 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. FIG. Therefore, by setting the operation start distance K2 and the operation stop distance K4, respectively, the amount of ice produced in the ice making unit 11 can be changed.

Further, the tank 13 is configured such that when the water in the tank 13 exceeds a predetermined overflow water level L1, the water exceeding the overflow water level L1 can be discharged to the outside of the tank 13, and the operation start distance K2 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 prevent the water in the tank 13 from exceeding the overflow water level L1 and being drained during the ice-making operation.

Further, the control unit 80 controls the control unit 80 when the distance to the water surface measured by the distance sensor 22 becomes 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. is equal to or smaller than the second abnormal distance K6, an error notification process is executed to notify an error. 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 it becomes the second abnormal distance K6 or less), By notifying the error, the operator can be notified of the abnormality in the water level in the tank 13 .

An ice storage tank 14 (ice storage unit) capable of storing ice produced by the ice making unit 11 and an upper surface 14D of the ice stored in the ice storage tank 14 are arranged above the ice stored in the ice storage tank 14. and an ice storage unit side distance sensor 23 capable of measuring the distance to the ice storage unit. As the amount of ice stored in the ice storage tank 14 increases, the upper surface of the ice rises, so the distance from the ice storage unit side distance sensor 23 to the upper surface of the ice decreases. As a result, by providing the ice storage section 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 .

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 unit 11 and the pump 15. , 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. The control unit 80 controls the water supply valve 30 A first process of supplying water from the water pipe 31 to the tank 13 by opening the tank 13 and the ice making by operating the pump motor 33 with the cooling device 40 stopped, which is executed after the first process. a second process of circulating water between the units 11; and a second process, which is executed after the second process. A third process of draining water to the outside is periodically performed.

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

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

In addition, a UV sterilization device 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 sterilization device 70 after executing the third process. , the fourth process of sterilizing the water in the tank 13 is executed. The water in the tank 13 that could not be drained by the third treatment can be sterilized by the UV sterilizer. Thereby, the inside of the tank 13 can be kept in a cleaner state. In addition, in this embodiment, when the water pipe 31 is provided with a water purifier that removes chlorine, it becomes easier for bacteria to propagate in the residual water. Therefore, it is particularly preferable to perform the above-described first to fourth processes in a configuration in which a water purifier is provided.

<Other embodiments>
The present invention is not limited to the embodiments explained by the above description and drawings, and the following embodiments are also included in the technical scope of the present invention.
(1) In the above-described embodiment, the ice making machine of the downstream type was exemplified, but the system of the ice making machine is not limited to the downstream type. The technology described herein can also be applied to other types of ice making machines (eg, cellular type) in which water circulates between the tank and the ice making section.
(2) In the above embodiment, the range sensor 22 using ultrasonic waves was exemplified, but the present invention is not limited to this. As the distance sensor 22, a configuration that measures the distance to the water surface by irradiating the water surface with a laser may be used. In addition, when the laser is difficult to reflect on the water surface, a reflective member with a high light reflectance (for example, a cylindrical float) is floated on the water surface, and the laser is directed toward the reflective member to reduce the distance to the water surface. It is good also as a structure which measures. Moreover, as a 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 process (step S4 in FIG. 5) of the above embodiment, for example, water is supplied to the water level of the tank 13 to the same height as the overflow water level L1, and the water level is set as the operation start water level, and is lower than this water level by a predetermined value. The water level may be the shutdown water level. Alternatively, the water level at that time may be set as the operation start water level without executing the additional water supply process, and the water level lower than this water level by a predetermined value may be set as the operation stop water level. Furthermore, in the additional water supply process, after the water level of the tank 13 reaches the same level as the overflow water level L1, the control unit 80 further supplies water for a predetermined time, and sets the water level at that time (overflow water level) 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 process (step S4 in FIG. 5), if the water level of the tank 13 is supplied to the same height as the overflow water level L1, ice-making water is supplied 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 temperature sensor 16 and the water temperature sensor 17 becomes a predetermined temperature (eg, 5° C.) or lower). When the pump 15 is operated to cool the ice-making water, the water scatters as it flows down the ice-making surface 12A. Since the water level in the tank 13 drops when the water scatters, ice making is performed from the water level lower than the operation start water level to the operation end water level, and ice smaller than a desired size is made. By continuing to supply water until the temperature of the ice-making water reaches a certain low temperature (a temperature close to 0° C.), the ice-making water can be cooled and the amount of water scattered by the ice-making plate can be replenished. The water level can be maintained at the overflow water level L1, which is the operation start water level, and the amount of water that has decreased from the operation start water level to the operation stop water level can be made into ice, so ice of a desired size can be made more reliably. can do.
(5) In the above embodiment, the user operates the operation unit 55 to start the ice making operation, but the present invention is not limited to this. For example, when the distance to the upper surface of the ice measured by the ice storage unit distance sensor 23 (the amount of ice stored in the ice storage tank 14) exceeds a predetermined distance (the ice storage The ice-making operation may be started when the amount of ice in the tank 14 is less than a predetermined amount. In other words, the controller 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 condition FE3 or the condition FE4 is satisfied for a predetermined time during the deicing operation or the cleaning operation.
(7) In the above embodiment, the predetermined temperatures C1, C2, C3, C4 and C5 and the predetermined times T1, T3, T4, T5, T6, T7, T8, T9 and T10 are not limited to the numerical values given as examples. , can be set as appropriate.
(8) In the residual water treatment operation, the control unit 80 may execute only the first to third processes without executing the fourth process.

DESCRIPTION OF SYMBOLS 10... Ice-making machine 11... Ice-making part 12... Ice-making plate 12A... Ice-making surface 13... Tank 14... Ice storage tank (ice storage part) 14D... Upper surface of ice stored in the ice storage part 15... Pump 16 Ice-making unit temperature sensor 17 Water temperature sensor 18 Piping connecting ice-making unit and pump 19 Intermediate part of pipe 20 Drain pipe 21 Drain valve for opening and closing the drain pipe 22 Distance sensor ( water level sensor), 23... ice storage unit 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 (10)

an ice making unit that makes ice by freezing water;
a cooling device for cooling the ice making unit;
a tank to store water and
a pump comprising a pump motor capable of changing a rotational speed, the pump being capable of supplying water in the tank to the ice making section as the pump motor is driven;
a control unit;
The tank has a structure in which unfrozen water out of the water supplied to the ice making unit is stored in the tank,
The control unit is configured to operate the cooling device and the pump motor to execute an ice-making operation for making ice in the ice-making unit, and in the ice-making operation, control the rotation speed of the pump motor ,
Equipped with a water level sensor capable of measuring the water level of water stored in the tank,
The ice-making unit comprises an ice-making plate having an ice-making surface on which water flows down,
The tank is arranged below the ice making plate,
The ice making machine, wherein the control section gradually lowers the rotation speed of the pump motor as the water level measured by the water level sensor decreases during the ice making operation. An ice making unit temperature sensor capable of detecting the temperature of the ice making unit,
When the temperature detected by the ice-making unit temperature sensor falls below a predetermined temperature higher than 0° C. during the ice-making operation, the control unit reduces the rotational speed of the pump motor, and after a predetermined time has passed, 2. The ice making machine according to claim 1, wherein a process for increasing the rotational speed of said pump motor is performed. A water temperature sensor capable of detecting the temperature of water stored in the tank,
The controller reduces the rotation speed of the pump motor when the temperature detected by the water temperature sensor falls below a predetermined temperature higher than 0° C. during the ice making operation, and after a predetermined time has passed, the pump motor 2. The ice making machine according to claim 1, wherein the processing for increasing the rotational speed of the motor is performed. The pump motor is a DC motor,
2. The controller determines that the water circulation between the tank and the ice making unit is not normal when the rotation speed of the pump motor is equal to or lower than a predetermined rotation speed. The ice making machine according to any one of claims 3. The pump motor is a DC motor,
2. The controller determines that the water circulation between the tank and the ice making unit is not normal when the current value of the pump motor is equal to or higher than a predetermined current value. The ice making machine according to any one of claims 4. The control unit operates the pump motor while the cooling device is stopped, thereby executing a washing operation in which water is circulated between the tank and the ice making unit,
6. The ice making machine according to any one of claims 1 to 5, wherein during the cleaning operation, a process of decreasing 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 unit and the pump;
a drain pipe drawn from an intermediate portion of the pipe for draining the water in the tank to the outside;
a drainage valve that opens and closes the drainage pipe,
The ice-making unit is arranged at a position higher than the pump,
The control unit operates the pump motor with the drain valve open to perform a drain operation for draining the water in the tank to the outside through the drain pipe,
7. The pump motor according to any one of claims 1 to 6, wherein in the water discharge operation, the rotation speed of the pump motor is controlled so that the height of the water pumped up by the pump is between the ice making section and the intermediate section. 1. 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 unit and the pump;
a drain pipe drawn from an intermediate portion of the pipe for draining the water in the tank to the outside;
a drainage valve that opens and closes the drainage pipe,
The control unit
a first process of supplying water from the external water source to the tank by opening the water supply valve;
a second process which is executed after the first process and circulates water between the tank and the ice making unit by operating the pump motor while the cooling device is stopped;
A third process, which is executed after the second process and drains the water in the tank to the outside through the drain pipe by operating the pump motor with the drain valve open, is periodically performed. The ice making machine according to any one of claims 1 to 5. The ice making machine according to claim 8, wherein the control unit executes the first process, the second process and the third process when the power of the ice making machine is switched from an off state to an on state. Equipped with a UV sterilization device that sterilizes the water in the tank by irradiating the water in the tank with ultraviolet rays,
10. The ice making machine according to claim 8 or 9, wherein, after executing the third process, the controller operates the UV sterilizer to perform a fourth process of sterilizing the water in the tank. .

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