CN114930100A - Ice making machine - Google Patents

Abstract

An ice maker, comprising: an ice making unit (11) for making ice by freezing water; a cooling device (40) that cools the ice making unit (11); a tank (13) for storing water; a pump (15) which is provided with a pump motor (33) with a variable rotation speed and can supply water in the tank (13) to the ice making part (11) along with the driving of the pump motor (33); and a control unit (80), wherein the tank (13) is configured to store unfrozen water in the water supplied to the ice-making unit (11) in the tank (13), and the control unit (80) executes an ice-making operation for making ice in the ice-making unit (11) by operating the cooling device (40) and the pump motor (33), and controls the rotation speed of the pump motor (33) during the ice-making operation.

Description

Ice maker

technical field

The present invention relates to ice making machines.

Background technique

Conventionally, as an ice maker, for example, the ice maker described in Patent Document 1 has been known. Patent Document 1 describes an ice maker having a structure in which water stored in a tank (ice making water tank) is supplied to an ice making unit (ice making plate) by a pump (circulation pump). In Patent Document 1, the water unfrozen in the ice making unit is returned to the tank. Therefore, water (ice making water) can be circulated between the tank and the ice making unit by the pump.

prior art literature

Patent Literature

Patent Document 1: Japanese Patent No. 5448618

(The problem to be solved by the invention)

In addition, as a pump motor included in a pump for circulating water between the tank and the ice maker, an AC motor having a constant rotational speed is generally used. When the rotational speed of the pump motor is constant, there is a problem that the circulation amount of water between the tank and the ice maker cannot be changed. For example, when the ice making operation of making ice is performed in the ice making unit, when the circulation amount of water is large, the ice making water is likely to be supercooled, and there is a fear that ice cream may be generated. However, when the circulation amount of water is reduced so as to avoid the generation of ice cream, it takes time to cool the ice-making water in the initial stage of the ice-making operation, and the ice-making efficiency decreases. Under such circumstances, an ice maker capable of increasing or decreasing the circulation amount of water between the tank and the ice making portion during the ice making operation is desired.

SUMMARY OF THE INVENTION

The present invention was made based on the above-mentioned circumstances, and an object thereof is to provide an ice maker capable of increasing or decreasing the circulation amount of water between the tank and the ice maker.

(Means for solving problems)

As means for solving the above-mentioned problems, the ice maker disclosed in this specification is characterized by including: an ice maker for producing ice by freezing water; a cooling device for cooling the ice maker; and a tank for storing water a pump including a pump motor whose rotational speed can be changed, and capable of supplying water in the tank to the ice making unit in response to driving of the pump motor; and a control unit for supplying the tank to the ice making unit A structure in which unfrozen water in the water in the unit is stored in the tank, the control unit performs an ice-making operation for producing ice in the ice-making unit by operating the cooling device and the pump motor, and During the ice making operation, the rotational speed of the pump motor is controlled.

In the above configuration, by driving the pump motor, water (ice making water) can be circulated between the tank and the ice making unit. Furthermore, by increasing or decreasing the rotational speed of the pump motor, the circulation amount of the ice-making water between the tank and the ice-making unit can be increased or decreased. In the initial stage of the ice making operation, it is preferable to operate the pump motor at a relatively high rotation speed to increase the circulation amount of the ice making water, thereby efficiently cooling the ice making water in the ice making unit. However, when the ice-making water is sufficiently cold and the circulation of the ice-making water is large, the ice-making water is supercooled to generate ice cream in the tank, which may hinder the circulation of the ice-making water. In the above configuration, the control unit can reduce the rotational speed of the pump motor during the ice making operation. Therefore, the circulation amount of the ice making water between the tank and the ice making unit can be reduced at a predetermined timing, thereby suppressing the generation of ice flakes. .

Furthermore, the ice maker may be provided with an ice making unit temperature sensor capable of detecting the temperature of the ice making unit, and the control unit may perform the following processing during the ice making operation: When the temperature detected by the ice maker temperature sensor is equal to or lower than a predetermined temperature higher than 0° C., the rotational speed of the pump motor is decreased, and the rotational speed of the pump motor is increased after a predetermined time has elapsed. .

During the ice-making operation, the ice-making water is cooled, and the temperature of the ice-making part is lowered along with this. The flow rate of the ice making water in the ice making section when the rotational speed of the pump motor is reduced in a state where the temperature of the ice making section is lower than a predetermined temperature (a temperature higher than 0°C) (a state in which the ice making water is sufficiently cold) When the temperature of the ice making unit is lowered, the temperature of the ice making unit is further lowered, whereby seed ice is likely to be generated in the ice making unit. When a kind of ice is produced, the ice grows with this kind of ice as a nucleus. Then, when ice exists in the ice making unit, the heat exchange efficiency in the ice making unit decreases, so that it becomes difficult to cool the ice making water, and it becomes difficult to cause supercooling. Therefore, after the seed ice is formed by lowering the rotation speed of the pump motor for a predetermined time, and then increasing the rotation speed of the pump motor, it is possible to suppress the generation of ice floes and to produce ice more quickly.

Furthermore, the ice maker may include a water temperature sensor capable of detecting the temperature of the water stored in the tank, and the control unit may perform the following processing during the ice making operation: When the temperature detected by the water temperature sensor is equal to or lower than a predetermined temperature higher than 0° C., the rotational speed of the pump motor is decreased, and the rotational speed of the pump motor is increased after a predetermined time has elapsed.

During the ice making operation, the ice making water that has passed through the ice making unit is stored in the tank, so the water temperature of the tank follows the temperature of the ice making water in the ice making unit. In a state where the water temperature of the tank is below a predetermined temperature (a temperature higher than 0°C) (a state in which the ice-making water is sufficiently cold), when the rotational speed of the pump motor is reduced, the flow rate of the ice-making water in the ice-making unit decreases, The temperature of the ice making unit is further lowered, whereby seed ice is likely to be generated in the ice making unit. When a kind of ice is produced, the ice grows with this kind of ice as a nucleus. Then, when ice exists in the ice making unit, the heat exchange efficiency in the ice making unit decreases, so that it becomes difficult to cool the ice making water, and it becomes difficult to cause supercooling. Therefore, after the seed ice is formed by lowering the rotation speed of the pump motor for a predetermined time, and then increasing the rotation speed of the pump motor, it is possible to suppress the generation of ice floes and to produce ice more quickly.

In addition, the pump motor may be a DC motor, and when the rotation speed of the pump motor is equal to or lower than a predetermined rotation speed, the control unit may determine that the water between the tank and the ice making unit has a The cycle is not working properly. When scale is deposited on the water circulation path between the tank and the ice maker, the water circulation is hindered, and the load acting on the pump motor increases, so that the rotation speed of the pump motor decreases. Therefore, the control unit can determine that the circulation of the water between the tank and the ice making unit is not normally performed when the rotational speed is equal to or lower than the predetermined rotational speed.

In addition, the pump motor may be a DC motor, and when the current value of the pump motor is equal to or greater than a predetermined current value, the control unit may determine that there is a connection between the tank and the ice making unit. The circulation of water is not working properly. When scale is deposited on the water circulation path between the tank and the ice maker, the water circulation is hindered, and the load acting on the pump motor increases, so that the current of the pump motor increases. Therefore, when the current value of the pump motor is equal to or greater than the predetermined current value, the control unit can determine that the circulation of the water between the tank and the ice making unit is not normally performed.

Furthermore, the ice maker may include a water level sensor capable of measuring the water level of water stored in the tank, and the ice making portion may include an ice making plate having ice making through which water supply flows. On the other hand, the tank is arranged below the ice making plate, and the control unit gradually increases the rotational speed of the pump motor as the water level measured by the water level sensor decreases during the ice making operation. low processing.

In the above-mentioned configuration, the water level of the tank is lowered as the ice on the ice making surface grows (increases). In addition, in the process of water flowing down on the ice making surface, the water may be bounced off by the ice on the ice making surface and scattered, and the larger the ice, the larger the amount of water scattered. Therefore, by gradually reducing the rotational speed of the pump motor as the water level becomes lower, the amount of scattering of water can be reduced, and the water can be returned to the tank more reliably. In addition, by reducing the rotational speed of the pump motor, the amount of water in the circulation path between the tank and the ice making plate can be reduced. By reducing the amount of water that is on the circulation path, water savings can be achieved because the water on the circulation path is not used for ice making.

In addition, the control unit may perform a washing operation of circulating water between the tank and the ice making unit by operating the pump motor in a state where the cooling device is stopped. During the cleaning operation, the process of reducing the rotational speed of the pump motor and the process of increasing the rotational speed of the pump motor are alternately repeated. In the cleaning operation, by circulating water between the tank and the ice maker, the water circulation path can be cleaned. In addition, during the cleaning operation, by repeatedly increasing and decreasing the rotational speed of the pump motor, the water can be pulsated on the circulation path, and the water circulation path can be washed more efficiently.

In addition, the ice maker may include a pipe connecting the ice making unit and the pump, and a drain pipe drawn out from an intermediate portion of the pipe and used to direct the water in the tank to the outside discharge; and a drain valve for opening and closing the drain pipe, the ice making unit is arranged at a position higher than the pump, and the control unit executes the operation by causing the pump to operate in a state where the drain valve is opened A drain operation in which the electric motor operates to drain the water in the tank to the outside through the drain pipe, and in the drain operation, the control unit sets the height of the water pumped up by the pump as the ice making operation The rotational speed of the pump motor is controlled in a manner of a height between the part and the middle part.

By operating the pump, in addition to supplying the water to the ice maker, it is possible to discharge the water in the tank. In addition, since the height (lift) of the water pumped up by the pump in the drainage operation is set to the height between the ice maker and the intermediate portion, the water in the tank can be suppressed from heading toward the ice maker, and drainage can be performed reliably.

Further, the ice maker may include: 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; and a pipe for connecting the ice making unit connected to the pump; a drain pipe drawn from an intermediate portion of the pipe for discharging the water in the tank to the outside; and a drain valve for opening and closing the drain pipe, and the control unit periodically Execute: a first process of supplying water from the external water source to the tank by opening the water supply valve; a second process of executing after the first process by stopping the cooling device operating the pump motor to circulate water between the tank and the ice making unit; and a third process, which is performed after the second process, by causing the drain valve to open The pump motor operates to drain the water in the tank to the outside through the drain pipe.

When the ice making operation is performed, the water circulating between the tank and the ice making unit is in a cold state. On the other hand, when the state in which the ice making operation is not performed continues for a long time, the water temperature of the water remaining in the water circulation path (hereinafter simply referred to as the circulation path) between the tank and the ice making unit rises, which is considered to be bacteria. easy to reproduce. By performing the first to third processes, the water remaining in the circulation path can be washed with the supplied water and discharged. By regularly performing such first processing to third processing, even when the state in which the ice making operation is not performed continues for a long time, the inside of the circulation path can be maintained in a cleaner state.

Furthermore, when the power supply of the ice maker is switched from an off state to an on state, the control unit may execute the first process, the second process, and the third process. When the state where the power supply of the ice maker is turned off continues for a long time with water remaining in the circulation path, the water temperature of the water remaining in the circulation path rises, and it is considered that bacteria are likely to multiply. Therefore, when the power supply is switched to the ON state, by periodically executing the first to third processes in this order, the inside of the circulation path can be brought into a clean state before the ice making operation is performed.

Furthermore, the ice maker may include a UV sterilization device that sterilizes the water in the tank by irradiating ultraviolet rays to the water in the tank, and the control unit may be executed after the execution of the After the third treatment, a fourth treatment of sterilizing the water in the tank by operating the UV sterilizing device is performed. The water in the tank that is not drained by the third treatment can be sterilized by the UV sterilizer. Thereby, the inside of the tank can be brought into a cleaner state.

(invention effect)

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

Description of drawings

FIG. 1 is a diagram showing an ice maker.

Fig. 2 is a perspective view showing an ice maker.

3 is an enlarged cross-sectional view showing the vicinity of the in-tank storage tube.

Fig. 4 is a block diagram showing an electrical configuration of the ice maker.

FIG. 5 is a flowchart showing the processing of the control unit of the ice making operation.

FIG. 6 is a flowchart showing the processing of the control unit of the deicing operation.

FIG. 7 is a flowchart showing the processing of the control unit of the cleaning operation.

FIG. 8 is a diagram showing an ice maker of a comparative example.

FIG. 9 is a flowchart showing the processing of the control unit of the residual water treatment operation.

FIG. 10 is a time chart showing the timing of executing the residual water treatment operation.

FIG. 11 is a flowchart showing the processing of the control unit when the power supply is turned on.

Detailed ways

An embodiment of the present invention will be described with reference to FIGS. 1 to 11 . In the present embodiment, the downflow ice maker 10 is exemplified as the ice maker. The ice maker 10 includes, as shown in FIG. 1 , a plurality of ice making units 11 for producing ice by freezing water, and cools the ice making units 11 (more specifically, each ice making plate 12 included in the ice making unit 11 ). The cooling device 40 , the tank 13 capable of storing water supplied to the ice making unit 11 , the ice storage tank 14 (ice storage unit) capable of storing ice produced by the ice making unit 11 , the tank 13 capable of supplying the ice making unit 11 water pump 15.

In addition, the ice maker 10 includes an ice maker temperature sensor 16 capable of detecting the temperature of the ice maker 11 (more specifically, the ice maker plate 12 ), a water temperature sensor 17 capable of detecting the temperature of the water stored in the tank 13 , and a A pipe 18 connecting the ice making unit 11 to the pump 15, a drain pipe 20 leading from the intermediate portion 19 of the pipe 18 and discharging the water in the tank 13 to the outside, and a drain valve 21 for opening and closing the drain pipe 20 are arranged in The distance sensor 22 that can measure the distance to the water surface 58 of the water stored in the tank 13 above the water stored in the tank 13 is arranged above the ice stored in the ice storage tank 14 and can measure the distance to the ice storage tank 14 The ice storage part side distance sensor 23 (the ice storage tank side distance sensor) of the distance to the upper surface 14D (refer FIG. 1 ) of the stored ice.

The ice making unit 11 includes a plurality of ice making plates 12 , sprinkler pipes 24 and sprinkler guides 25 . The ice making plate 12 is set in a vertical posture. Among the plurality of ice making plates 12 , a meandering evaporation tube 44 (a part of the cooling device 40 ) is provided between the pair of ice making plates 12 , 12 arranged to face each other. As shown in FIG. 2 , the ice making plate 12 has a plurality of ice making surfaces 12A extending in the up-down direction and a plurality of ridge portions 12B extending in the up-down direction. The plurality of ice-making surfaces 12A are arranged in the horizontal direction, and the adjacent ice-making surfaces 12A are partitioned by the ridge portions 12B. The ice-making surface 12A is constituted by the surface on the opposite side of the evaporation tube 44 of the ice-making plate 12 . Sprinkler pipes 24 (sprinklers) are provided for each pair of ice making plates 12 , 12 . The ice-making water sent from the pump 15 to the sprinkler pipe 24 is sprinkled on each ice-making surface 12A through the sprinkler pipe 24 . Then, the ice-making water sprayed from the sprinkler pipes 24 is guided to the respective ice-making surfaces 12A by the sprinkler guides 25 and then flows downward on the respective ice-making surfaces 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. 1 . The compressor 41, the condenser 42, the expansion valve 43, and the evaporation pipe 44 are connected by a refrigerant pipe 45 in which the refrigerant is enclosed. The compressor 41 compresses the 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 evaporation pipe 44 (evaporator) vaporizes the liquefied refrigerant expanded by the expansion valve 43 and cools the ice making plate 12 . In this way, the compressor 41 , the condenser 42 , the expansion valve 43 , the evaporation pipe 44 , and the refrigerant pipe 45 constitute a circulation loop (refrigeration circuit) of the refrigerant for cooling the ice making plate 12 . Further, the cooling device 40 is provided with a dryer 47 for removing water mixed in the refrigeration circuit. The ice making unit temperature sensor 16 is provided in the refrigerant pipe 45 near the outlet of the evaporation pipe 44 and can detect the temperature of the ice making plate 12 . In addition, as the ice making part temperature sensor 16, although a thermistor can be used, for example, it is not limited to this.

Further, the cooling device 40 includes a bypass pipe 49 for supplying the refrigerant gas (hot gas) compressed in the compressor 41 to the evaporation pipe 44 , and a hot gas valve 50 which is a solenoid valve provided in the bypass pipe 49 . By opening the hot gas valve 50 , the refrigerant gas (hot gas) can be supplied from the compressor 41 to the evaporation pipe 44 to heat the evaporation pipe 44 . That is, the cooling device 40 functions as a heating device that heats the evaporation tube 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 for ice-making is stored in the inner space of the tank main body portion 26 . The tank main body portion 26 is arranged below the ice making portion 11 . It should be noted that the lid body 27 is not provided at a portion of the tank body portion 26 located directly below the ice making portion 11 . In addition, a grating 28 is interposed between the tank main body 26 and the ice maker 11 . Thereby, the water flowing down from the ice making unit 11 passes through the grating 28 and is stored in the tank 13 .

In addition, a water supply pipe 52 (sprinkler pipe on the water supply side) is provided between the pair of ice making plates 12 and 12 . Further, the ice maker 10 includes a water supply pipe 29 for supplying water from a water supply pipe 31 (an 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 supply pipe 31 via the water supply pipe 29 and the water supply valve 30 . Thereby, when the water supply valve 30 is opened, 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). In addition, the unfrozen water in the ice-making water flowing down on the ice-making surface 12A is stored in the tank 13 . That is, the tank 13 has a structure in which the unfrozen water in the ice-making water supplied to the ice making unit 11 is stored in the tank 13 . Thereby, by operating the pump 15 , the ice making water can be circulated between the tank 13 and the ice making unit 11 . It should be noted that, in this specification, the ice-making water is not limited to the water used for ice-making, but also includes the water that circulates between the tank 13 and the ice-making part 11 .

The tank 13 is configured to be able to discharge the water exceeding the overflow level L1 to the outside of the tank 13 when the water in the tank 13 exceeds a predetermined overflow level L1 (refer to the two-dot chain line in FIG. 3 ). In more detail, in the tank main body part 26, the overflow space A2 is provided so that it may adjoin the water storage space A1 which stores water. The overflow space A2 has a function for discharging the water overflowed from the water storage space A1. The tank main body portion 26 has a standing wall portion 32 partitioning the overflow space A2 and the water storage space A1 . The height of the upper end of the standing wall portion 32 corresponds to the overflow water level L1 of the tank 13 . Thereby, when the water level of the water in the water storage space A1 exceeds the height of the upper end of the standing wall portion 32, the water passes over the upper end of the standing wall portion 32, flows into the overflow space A2, and is discharged. In addition, the overflow space A2 may be comprised by the overflow pipe provided in the tank 13.

The pump 15 includes a pump motor 33 whose rotational speed can be changed, and can supply water in the tank 13 to the ice making unit 11 in accordance with the driving of the pump motor 33 . The pump motor 33 is a DC motor (DC brushless motor) whose rotational speed can be changed. Thus, by increasing or decreasing the rotational speed of the pump motor 33, the supply amount of water to the ice making unit 11 (even the circulation amount of water between the tank 13 and the ice making unit 11) can be increased or decreased.

In addition, the ice making unit 11 is arranged at a position higher than the pump 15 , and the piping 18 extends upward from the pump 15 . In addition, a drain pipe 20 for discharging the water in the tank 13 to the outside is provided in the intermediate portion 19 of the piping 18 , and a drain valve 21 for opening and closing the drain pipe 20 is provided in the drain pipe 20 . Thereby, when the pump 15 is operated with the drain valve 21 open, the water in the tank 13 can be drained through the drain pipe 20 . When the pump 15 is operated in a state where clean water or detergent is put into the tank 13, the ice making surface 12A side of the ice making unit 11 can be washed. Moreover, the water supply pipe 29 and the piping 18 are connected via a part of the drain pipe 20 and the valve 34 . Accordingly, when the valve 34 is opened while the water supply valve 30 and the drain valve 21 are closed and the pump 15 is operated, 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, and the ice making plate can be washed. 12 on the back.

The distance sensor 22 is disposed above the water stored in the tank 13 and is an ultrasonic sensor capable of measuring the distance to the water surface of the water stored in the tank 13 by irradiating ultrasonic waves toward the water surface of the water in the tank 13 . More specifically, the distance sensor 22 includes an irradiation unit that irradiates ultrasonic waves and a receiving unit that receives ultrasonic waves reflected from the water surface of the water in the tank 13, and can be based on the time until the ultrasonic waves irradiated from the irradiation unit are reflected back to the receiving unit. to measure the distance from the distance sensor 22 to the water surface. The distance from the distance sensor 22 to the water surface is linked to the water level of the tank 13 , so the distance sensor 22 can be used as a water level sensor capable of measuring the water level of the water stored in the tank 13 . By using the distance sensor 22 as a water level sensor, the water level can be detected linearly.

As shown in FIG. 3 , the distance sensor 22 is accommodated in a accommodating tube 35 provided on the lid body 27 covering the tank 13 . By accommodating the distance sensor 22 in the storage tube 35 , the measurement error of the distance sensor 22 caused by the surrounding temperature change can be reduced. The storage tube 35 is a circular tube long in the vertical direction, and is arranged so as to penetrate the lid body 27 . The storage tube 35 is opened downward, and the lower end (open end) of the storage tube 35 and the bottom surface 13A of the tank 13 are arranged to face each other with a slight gap therebetween. Therefore, in the tank 13 , the water level of the water in the storage tube 35 is at the same height as the water level of the water outside the storage tube 35 . In addition, a cutout portion 36 is formed in the opening end portion (lower end portion) of the storage tube 35 . By providing such a cutout portion 36, it is possible to suppress the water fluctuation in the storage tube 35, and it is possible to improve the measurement accuracy of the water level.

In addition, an air hole 37 that communicates the inside and the outside of the storage tube 35 (the outside of the tank 13 ) is formed in the storage tube 35 at a position higher than the lid body 27 . The air hole 37 is arranged at a position higher than the lid body 27 . When the water level in the storage pipe 35 rises, the air in the storage pipe 35 is discharged to the outside through the air hole 37 by the rising amount of the water level.

The distance sensor 22 is provided on the top 35A of the storage tube 35 . 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 . In addition, the directivity angle of the ultrasonic wave irradiated from the distance sensor 22 is set so that the irradiation range H1 of the ultrasonic wave irradiated on the bottom surface 13A of the tank 13 is substantially equal to the cross-sectional area of the storage tube 35 . Thereby, it is possible to suppress the reflection of the ultrasonic waves irradiated from the distance sensor 22 by the inner surface of the storage tube 35 . In addition, although the directivity angle of the ultrasonic wave irradiated from the distance sensor 22 is set in the range of 5 degrees - 10 degrees, for example, it is not limited to this.

In addition, in the storage tube 35 , the first sound absorbing material 38 is provided so as to surround the distance sensor 22 from the entire circumference in the horizontal direction, and the second sound absorbing material 39 is provided so as to surround the first sound absorbing material 38 . The first sound absorbing material 38 and the second sound absorbing material 39 are made of different materials, for example, the first sound absorbing material 38 is made of a rubber material, and the second sound absorbing material 39 is made of a foam material. By surrounding the distance sensor 22 with the first sound absorbing material 38 and the second sound absorbing material 39 , the distance sensor 22 can be prevented from receiving external noise, and the measurement accuracy of the distance sensor 22 can be improved.

Furthermore, a water temperature sensor 17 (see FIG. 1 ) capable of detecting the temperature of the water stored in the tank 13 is provided between the pump 15 and the distance sensor 22 . The water temperature sensor 17 is attached to the cover body 27 and is provided so as to be in contact with the water in the tank 13 . In addition, as the water temperature sensor 17, although a thermistor can be used, for example, it is not limited to this.

The ice storage tank 14 stores the ice produced in the ice making unit 11 , as shown in FIG. The user takes the produced ice out of the ice storage tank 14 and uses it. It should be noted that the above-mentioned grating 28 constitutes a part of the ice discharge pipe 51 . The grate 28 is provided in a downward inclined posture toward the ice inlet 14A in the ice storage tank 14 . As a result, the ice dropped on the grating 28 is transported toward the inlet 14A. The ice storage unit side distance sensor 23 is an ultrasonic sensor provided on the upper wall portion 14B constituting the ice storage tank 14, and is formed so as to be able to measure the upper surface of the ice by irradiating ultrasonic waves on the upper surface 14D of the ice stored in the ice storage tank 14. The structure of the distance up to 14D.

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 upper surface of the ice becomes higher, so the distance from the ice storage unit side distance sensor 23 to the upper surface of the ice is reduced, and the ice in the ice storage tank 14 becomes smaller. When the amount of ice decreases, 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 structure of the ice maker 10 is demonstrated. The ice maker 10 includes a control unit 80 as shown in FIG. 4 . The control unit 80 is electrically connected to the cooling device 40 (more specifically, the compressor 41, the fan 46, the hot air valve 50), the distance sensor 22, the ice storage unit side distance sensor 23, the pump motor 33, and the ice making unit temperature sensor. 16 . Water temperature sensor 17 , water supply valve 30 , drain valve 21 , valve 34 , timer unit 53 (timer), storage unit 54 , and UV sterilization device 70 . Moreover, the ice maker 10 is provided with the operation part 55 which consists of switches which can be operated by a user, and the display part 56 (for example, a liquid crystal panel) which can display an error message, etc.. That is, the display unit 56 is a notification unit capable of notifying the operator of an error. The operation unit 55 and the display unit 56 are electrically connected to the control unit 80 , respectively.

The control unit 80 is constituted mainly by, for example, a CPU, and the storage unit 54 is constituted by, for example, a ROM, a RAM, and the like. By executing the program stored in the storage unit 54, the control unit 80 can be based on the operation of the operation unit 55 by the user, the respective sensors (the distance sensor 22, the ice storage unit side distance sensor 23, the ice making unit temperature sensor 16, the water temperature sensor 17) The operation of each device (cooling device 40 , pump motor 33 , water supply valve 30 , drain valve 21 , valve 34 , display unit 56 ) is controlled by the measured value of the measured value and the timing of the timer unit 53 . In addition, each setting value related to the operation of the ice maker is stored in the storage unit 54 . In addition, the control unit 80 can refer to the rotational speed and the current value of the pump motor 33 .

The control unit 80 can perform the ice making operation, the deicing operation, and the washing operation, respectively. The ice making operation is an operation of making ice in the ice making unit 11 by operating the cooling device 40 to cool the ice making plate 12 and operating the pump motor 33 . The deicing operation refers to an operation of heating the ice making plate 12 by operating the cooling device 40 and operating the pump motor 33 and the water supply valve 30 to release the produced ice from the ice making surface 12A of the ice making unit 11 . The cleaning operation refers to an operation of cleaning the circulation path of the ice-making water by operating the pump motor 33 while the cooling device 40 is stopped to circulate water between the tank 13 and the ice-making unit 11 (the details will be described later). ).

In addition, the control unit 80 can control the rotational speed of the pump motor 33 . In the present embodiment, as the rotational speed of the pump motor 33, five levels of rotational speed are set: high speed V1, medium speed V2, low speed V3, high speed V4A during cleaning, and low speed V4B during cleaning. It should be noted that V1>V2>V3, V4A>V1, and V4A>V4B, but the value of each rotational speed can be appropriately set. In addition, in the following description, "the control part 80 opens the water supply valve 30 and supplies tap water into the tank 13" may be called "water supply".

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

That is, the work start water level L2 is the water level of the water surface corresponding to the work start distance K2. The work start distance K2 (work start water level L2 ) can be appropriately set. The work start distance K2 is set so that the work start water level L2 is lower than the above-mentioned overflow water level L1, as shown in FIG. 3, for example. In addition, the work start water level L2 may be the same height as the overflow water level L1.

In the ice making operation, as shown in FIG. 5 , the control unit 80 cools the ice making plate 12 by operating the cooling device 40 (step S1 ). Then, the control unit 80 controls the rotational speed of the pump motor 33 based on the state of the ice on the ice making surface 12A during the ice making operation. Immediately after the ice making operation is started, 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 unit 11, and the ice making water is cooled while flowing up and down the cooled ice making surface 12A. Immediately after the ice making operation is started, the ice making water in the tank 13 has a temperature close to that of tap water (eg, 20° C.), and the ice making water needs to be cooled to 0° C. in order to freeze the ice making water. By operating the pump motor 33 at the high speed V1 immediately after the ice making operation, the circulation amount of the ice making water between the tank 13 and the ice making unit 11 can be increased, so that the ice making water can be cooled efficiently.

When the pump motor 33 is operated, the water in the tank 13 is sent to the circulation paths (piping 18 , the ice making unit 11 , etc.) of the ice-making water other than the tank 13 , and the water level in the tank 13 drops. Therefore, after the control unit 80 operates the pump motor 33 at the high speed V1, after a predetermined time T1 (for example, 15 seconds) has elapsed (YES in step S3), water is supplied until the water level in the tank 13 reaches the work start water level L2 (Step S4, additional water supply processing). That is, the tank 13 is replenished with the water in the amount reduced from the tank 13 due to the operation of the pump motor 33 . Then, the control unit 80 adds a predetermined value K3 (predetermined distance) to the work start distance K2 as the work stop distance K4 at the time when the additional water supply process is completed (the time when the water level in the tank 13 returns to the work start water level L2 ). Stored in the storage unit 54 . Since the value of the distance sensor 22 becomes the work stop distance K4, the ice making operation is stopped (details will be described later). It should be noted that the work stop distance K4 may be stored in the storage unit 54 at the time before the ice making operation (for example, the time when the work start distance K2 is input).

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

When the temperature of the ice-making water is lowered, the heat exchange between the ice-making water and the ice-making plate 12 is suppressed, and thus the temperature of the ice-making plate 12 is lowered. After the water level in the tank 13 has reached the work start water level L2 (after step S4), and when the following condition FA1 or condition FA2 is satisfied (YES in step S5), the control unit 80 causes the pump motor 33 to operate. Low speed V3 (step S6). The following predetermined temperatures C1 and C2 are values larger than 0°C and values in the vicinity of 0°C, and can be appropriately set. Preferably, the predetermined temperature C1 is set in a range of, for example, 1°C to 5°C, and the predetermined temperature C2 is set in a range of, for example, 2°C to 10°C. In other words, the control unit 80 sets the pump motor to the low speed V3 before the temperature of the ice making water becomes 0° C. (before ice is generated on the ice making surface 12A).

Condition FA1: The detected temperature of the water temperature sensor 17 measuring the water temperature of the tank 13≤predetermined temperature C1 (for example, 2.5°C)

Condition FA2: Detection temperature of ice making section 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 decreases and the amount of the ice making water flowing down the ice making surface 12A decreases, so the temperature of the ice making surface 12A further decreases. As a result, the ice nuclei (seed ice) are easily formed at the portion of the ice-making surface 12A corresponding to the evaporation tube 44 (the portion of the ice-making surface 12A where the temperature is particularly low). Furthermore, by setting the pump motor 33 to the low speed V3, cooling of the ice-making water can be suppressed, so that the ice-making water can be suppressed from being supercooled, and the generation of ice cream 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 intermediate speed V2 (step S8 ). The predetermined temperature C3 described below is a temperature higher than 0° C. and a temperature lower than the predetermined temperature C2 .

Condition FA3: The state in which the detected temperature of the ice making section temperature sensor 16≤predetermined temperature C3 (for example, 1° C.) continues for a predetermined time T3 (for example, 120 seconds).

In addition, the control unit 80 may set the pump motor 33 to the medium speed V2 when it is detected that seed ice is generated on the ice making surface 12A instead of the condition FA3. It should be noted that the detection of seed ice can be realized by, for example, 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 after the temperature of the ice making plate 12 is sufficiently lowered for a predetermined time T3, seed ice is produced on the ice making surface 12A. Therefore, when the condition FA3 is satisfied, the control unit 80 determines that the seed ice is generated, sets the pump motor 33 to the medium speed V2, and increases the circulation amount of the ice-making water. It should be noted that the predetermined time T3 can be appropriately set, and can be determined by, for example, measuring the time when the seed ice is actually generated by an experiment or the like.

That is, the control unit 80 executes a process of increasing the rotational speed of the pump motor 33 (to the intermediate speed V2 ) after a predetermined time has elapsed after the pump motor 33 is set to the low speed V3 . In the state where seed ice has been generated on the ice making surface 12A, the ice making water is frozen in the process of flowing down on the surface of the seed ice. Thereby, the half-moon-shaped ice 57 (see FIG. 1 ) protruding from the ice-making surface 12A grows as time elapses. In addition, when the ice 57 is produced on the ice making surface 12A, the heat exchange between the ice making surface 12A and the ice making water is suppressed by the ice 57, so the cooling rate of the ice making water decreases. Therefore, even if the rotational speed of the pump motor 33 is increased after the seed ice is generated, it is difficult to generate the seed ice.

Then, as the ice 57 grows on the ice making surface 12A, the water level in the tank 13 decreases. The control part 80 performs a rotation speed reduction process (step S9) after step S8. In the rotational speed lowering process, the rotational speed of the pump motor 33 is gradually decreased as the distance to the water surface measured by the distance sensor 22 increases (as the water level in the tank 13 measured by the water level sensor decreases). As the ice on the ice making surface 12A becomes larger, the ice making water supplied to the ice making plate 12 is easily scattered by being bounced off by the ice. The scattered ice-making water will not return to the tank 13, so the water used for ice-making is reduced, and the ice may be smaller than the desired size. Therefore, by gradually reducing 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. It should be noted that, in the rotational speed reduction process, the rotational speed of the pump motor 33 may be continuously decreased or may be decreased stepwise.

Then, when the water level in the tank 13 of the control unit 80 becomes the work stop water level L4 (YES in step S10, and the distance to the water surface detected by the distance sensor 22 becomes the work stop distance K4 larger than the work start distance K2 In the case of ), the pump motor 33 is stopped, the ice making operation is stopped, and the operation is transferred to the deicing operation. It should be noted that, instead of step S10, the control unit 80 may continue for a predetermined time T9 (for example, 20 seconds) in a state where “the water level in the tank 13 is the work stop water level L4 or lower” (the water level in the tank 13 is the work stop water level). L4 or less and stable), the pump motor 33 is stopped, the ice making operation is stopped, and the operation is shifted to the deicing operation. In this way, the influence of the change in the water level caused by the fluctuation of the water surface in the tank 13 can be suppressed, so that the size of the ice produced when the ice making operation is repeated can be made the same size every time.

In addition, when the following condition FE1 or condition FE2 is satisfied during the ice making operation, the control unit 80 determines that the circulation of the water between the tank 13 and the ice making unit 11 is not normally performed, and displays on the display unit 56 The user is notified of the error message "The circulation of water is not normally performed (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 an error (the circulation of water is not normally performed).

Condition FE1: rotational speed VX of pump motor 33 ≤ predetermined rotational speed V6

Condition FE2: Current value IX of pump motor 33 ≥ predetermined current value I1

It should be noted that the reason why the circulation of water between the tank 13 and the ice making unit 11 is not normally performed is that scale or the like is deposited in the circulation path of the ice making water. It should be noted that, in the circulation path, scales are particularly likely to be precipitated at locations where the flow velocity is slow (the end of the sprinkler pipe 24, the end of the sprinkler guide 25, and the like). Therefore, when the condition FE1 or the condition FE2 is satisfied, the control unit 80 may execute the cleaning operation as an error handling process. In addition, when the condition FE1 or the condition FE2 is satisfied, the control unit 80 may stop the operation of the ice maker 10 as an error handling process.

Then, when the following condition FE3 or condition FE4 is satisfied for a predetermined time during the ice making operation, the control unit 80 executes an error notification process for notifying an error. In the error notification process, the control unit 80 displays, for example, on the display unit 56, an error message notifying the user that "the water level of the tank is an abnormal water level".

Condition FE3: The distance to the water surface measured by the distance sensor 22 ≥ the first abnormal distance K5

Condition FE4: The distance to the water surface measured by the distance sensor 22 ≤ the second abnormal distance K6

It should be noted that 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 and the cleaning operation.

The first abnormal distance K5 is a value larger than the work stop distance K4. The second abnormal distance K6 is a value smaller than the work start distance K2. Therefore, when the distance to the water surface measured by the distance sensor 22 is greater than or equal to the first abnormal distance K5, it corresponds to a significant drop in the water level of the tank 13 . It should be noted that the first abnormal distance K5 is, for example, a value corresponding to the safety water level L5 of the pump 15 , and the safety water level L5 is a water level at which the discharge amount of the pump 15 becomes unstable at a lower water level. In addition, when the distance to the water surface measured by the distance sensor 22 is equal to or less than the second abnormal distance K6, the water level of the tank 13 is significantly increased. It should be noted that, as shown in FIG. 3 , the second abnormal distance K6 is a value corresponding to the water level L6 higher than the overflow water level L1 . Therefore, the reason why the above-mentioned condition FE4 is satisfied is that the water level in the tank 13 cannot be accurately measured because the water level in the tank 13 cannot be accurately measured because the water level in the tank 13 cannot be accurately measured because the distance sensor 22 is not installed in a regular position.

Next, the processing of the control unit 80 in the deicing operation will be described. In the deicing operation, as shown in FIG. 6 , the control unit 80 executes a drainage operation (drainage) in which the water in the tank 13 is drained to the outside through the drain pipe 20 by operating the pump motor 33 with the drain valve 21 open. processing) (step S21). When the water level of the tank 13 drops due to the drainage and the distance detected by the distance sensor 22 becomes a distance corresponding to the bottom surface 13A of the tank 13 set in advance (the height of the bottom surface 13A is detected), the control unit 80 determines that the drainage is completed. , the pump motor 33 is stopped, the drain valve 21 is closed, and the drain operation is stopped.

It should be noted that, in the ice making operation of the downflow ice maker, the impurities contained in the water in the tank 13 are difficult to freeze on the ice making surface 12A and are collected into the tank 13, so the ice 57 is in a state with few impurities (exceeding the amount of impurities). 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. This concentrated water is what causes scale in the circulation path. Therefore, it is preferable to discharge the concentrated water by performing the drainage operation immediately after the ice-making operation as described above. In addition, during the draining operation, the control unit 80 controls the rotational speed of the pump motor 33 (at least the speed lower than the low speed V3 described above) so that the height of the water pumped up by the pump 15 is equal to the height between the ice making unit 11 and the intermediate unit 19 . speed) to control. Thereby, it can suppress that the water in the tank 13 to be drained goes to the ice making part 11, and it can drain more reliably.

Next, the control part 80 stops the fan 46 and opens the hot air valve 50 (step S22). Thereby, the refrigerant gas (hot gas) can be supplied from the compressor 41 to the evaporating pipe 44, and the evaporating pipe 44 (and even the ice making plate 12) can be heated. Then, by opening the water supply valve 30, the control unit 80 causes the tap water to flow down toward the back surface of the ice making plate 12 via the water supply pipe 52 (step S23). Thereby, the ice making plate 12 is heated by the tap water and hot air, and the contact portion of the ice 57 with the ice making surface 12A is melted, whereby the ice 57 is peeled off (de-icing) from the ice making surface 12A. The detached ice is stored in the ice storage tank 14 after falling onto the grates 28 . And the tap water which flows down on the back surface of the ice making plate 12 falls into the tank 13, and the water level in the tank 13 rises by this. When the water level in the tank 13 rises and reaches the work start water level L2 (the distance to the water surface detected by the distance sensor 22 is the work start distance K2) (YES in step S24), the control unit 80 closes the water supply valve and The water supply is stopped (step S25).

In addition, when the ice 57 is detached, the thawing water in which a part of the ice 57 (the contact part with the ice making surface 12A) melted is recovered to the tank 13 . Since such thawing water has few impurities, it is preferable to reuse it for ice making without discharging it. Therefore, by stopping the water supply at the work start water level L2 lower than the overflow water level L1 as in steps S24 and S25, it is possible to prevent the thawing water from overflowing and draining.

Then, when the temperature of the ice making plate 12 rises to a certain degree 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 stopped after operating at the medium speed V2 for a predetermined time T5 (for example, 15 seconds), and after a predetermined time T6 (for example, 30 seconds), the pump motor 33 is operated at, for example, the medium speed V2. It stops after working for a predetermined time T7 (for example, 15 seconds). In this way, ice-making water can be flowed toward the ice-making surface 12A in a state where the temperature of the ice-making plate 12 has risen to a certain degree, so that the detachment of the ice can be promoted.

Condition FB1: Detected temperature of ice making section temperature sensor 16 ≥ predetermined temperature C4 (for example, 4°C)

It should be noted that in a state where the contact portion of the ice 57 with the ice making surface 12A is melted, the ice 57 is difficult to peel off from the ice making surface 12A due to the surface tension of the water between the ice 57 and the ice making surface 12A. state. Therefore, as described above, after the contact portion of the ice 57 with the ice making surface 12A is melted, the pump motor 33 is activated to flow the ice making water toward the ice making surface 12A, thereby knocking off the ice 57 by the force of the water, Thereby, deicing can be promoted. However, when the 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 part of the ice making plate 12) and the evaporating pipe 44 The temperature of the outlet side (the side of the ice making section temperature sensor 16, corresponding to the lower part of the ice making plate 12) is more likely to increase in temperature. That is, the contact portion of the ice 57 on the upper side of the ice making surface 12A with the ice making surface 12A melts quickly. Therefore, in the present embodiment, first, the pump motor 33 is operated at the medium speed V2 for the predetermined time T5, whereby the ice 57 located in the upper part of the ice making surface 12A (about the upper half of the ice making surface 12A) which is relatively easy to melt is melted break away. Then, after the predetermined time T6 has elapsed, after the contact portion of the ice 57 located at the lower part of the ice making surface 12A with the ice making surface is melted, the pump motor 33 is operated at the medium speed V2 for the predetermined time T7, thereby causing the lower ice 57 to melt. break away.

Then, when the predetermined time T8 (for example, 60 seconds) has elapsed after the following condition FB2 is satisfied (YES in step S28 ) (YES in step S29 ), the control unit 80 determines that ice making All the ice on the surface 12A is released, the deicing operation is stopped, and the operation is shifted to the ice making operation. It should be noted that the predetermined temperatures C4 and C5 can be appropriately set, but the predetermined temperatures C4 and C5 are set to be higher than 0° C., and the predetermined temperature C5 is set to be higher than the predetermined temperature C4 .

Condition FB2: Detected temperature of ice making section temperature sensor 16 ≥ predetermined temperature C5 (eg, 9°C)

It should be noted that the control unit 80 repeatedly performs the ice making operation and the deicing operation until the distance to the upper surface 14D of the ice measured by the ice storage unit side distance sensor 23 (corresponding to the amount of ice stored in the ice storage tank) ) reaches a predetermined distance K7 (until the ice in the ice storage tank reaches a predetermined amount). In addition, since the predetermined distance K7 (the amount of ice in the ice storage tank) can be appropriately set, the amount of ice in the ice storage tank 14 can be adjusted. In addition, when performing the ice-making operation after the second time, the control unit 80 may omit the water supply processing (processing of supplying tap water to the operation start water level L2 ) performed before the ice-making operation.

Then, the control unit 80 executes the cleaning operation after the deicing operation on the condition that the cycle of the ice making operation and the deicing operation is performed a predetermined number of times (for example, 20 times). Next, the processing of the control unit 80 in the cleaning operation will be described. During the cleaning operation, as shown in FIG. 7 , the control unit 80 stops the cooling device 40 (the compressor 41 and the fan 46 ) and brings the hot air valve 50 into a closed state (step S41 ). Next, the control unit 80 opens the water supply valve 30 to supply water to the tank (step S42 ), and based on the distance to the water surface (water level in the tank 13 ) measured by the distance sensor 22 , the water level in the tank 13 becomes a predetermined water level ( For example, in the case of overflowing water level L1) (YES in step S43), the water supply valve is closed (step S44).

Next, the control unit 80 operates the pump motor 33 and opens the valve 34 while the cooling device 40 is stopped, thereby circulating water between the tank 13 and the ice making unit 11 (the surface and the back surface of the ice making plate 12 ). . During the cleaning operation, the control unit 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, after the control unit 80 has performed the first operation process of operating the pump motor 33 at a rotational speed higher than the high speed V1, that is, operating the high speed V4A during cleaning for a predetermined time (step S45), the control unit 80 performs the operation of operating the low speed V4B during cleaning for a predetermined time. The second work process (step S46). The control unit 80 repeatedly executes the first operation process and the second operation process alternately. Then, after the control unit 80 executes the first operation process and the second operation process a predetermined number of times respectively (YES in step S47 ), the control unit 80 executes the pump motor by opening the drain valve 21 and closing the valve 34 33 is actuated to drain the water in the tank 13 (drainage processing) (step S48). Thereby, the cleaning operation is stopped. In addition, the control part 80 transfers to the ice making operation after the washing operation is stopped.

Furthermore, 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 as an example, but the present invention is not limited to this. When the concentration of impurities contained in the water in the tank 13 is measured by the sensor and the concentration of the impurities is equal to or greater than a predetermined value, the control unit 80 may execute the cleaning operation after the deicing operation. It should be noted that the higher the concentration of impurities in the water, the higher the conductivity. Therefore, in the present embodiment, an electrical conductivity sensor capable of measuring electrical conductivity may be provided. Such a conductivity sensor is electrically connected to the control unit 80, and the conductivity sensor is used to measure the conductivity of water, and the control unit 80 can perform cleaning when the measured conductivity is equal to or higher than a predetermined value (the concentration of impurities is equal to or higher than a predetermined value). Operation. In addition, the water temperature sensor 17 is comprised by accommodating a thermistor in the metal case 17A (the case part of the water temperature sensor 17, see FIG. 3), for example. When using the water temperature sensor 17 of such a structure, as shown by the two-dot chain line in FIG. 3, the electrode 48 arrange|positioned so that the water in the tank 13 may be arrange|positioned may be provided. The electrode 48 is arranged to be spaced apart from the case 17A, and the electrode 48 and the case 17A are electrically connected to the control unit 80 . The control unit 80 can measure the conductance of the water in the tank 13 by energizing both the electrode 48 and the case 17A to flow an electric current in the water between the electrode 48 and the case 17A, and measuring the electrical resistance of the water. Rate. That is, one electrode (for example, the positive electrode) of the pair of electrodes constituting the conductivity sensor may be composed of the electrode 48 , and the other electrode (for example, the negative electrode) may be composed of the case 17A.

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

In the present embodiment, even when the water is drained by the pump 15, there is a possibility that the water circulation path (including the tank 13 and the ice making unit 11) of the water between the tank 13 and the ice making unit 11 may partially remain in the water circulation path (including the tank 13 and the ice making unit 11). water situation. In the following description, the water remaining in the circulation path without being drained is called residual water. As an example of the site|part where residual water arises, the bottom part of the tank 13 is mentioned, for example. A water suction port (not shown) is provided at the lower end of the pump 15. Therefore, in order to suck in water by the pump 15, it is necessary to provide a concave portion 13D in the bottom surface 13A of the tank 13 as shown in FIG. A gap is provided between the lower ends of 15 . In this case, for example, there is a little residual water at the bottom (recess 13D) of the tank 13 that cannot be sucked by the pump 15 . When the ice making operation is not performed for a long time or the like, it is assumed that the water temperature of the remaining water rises. When the water temperature of the remaining water rises, there is a fear of bacterial growth.

Therefore, in the present embodiment, the control unit 80 executes the residual water treatment operation for treating the residual water. In the residual water treatment operation, as shown in FIG. 9 , the following first to fourth processes are sequentially performed. In the first process (residual water dilution process, step S51 ), the control unit 80 opens the water supply valve 30 to supply the water (tap water) from the water pipe 31 to the tank 13 . Thereby, 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 level L1 (see FIG. 3 ), the control unit 80 continues water supply for a predetermined time, and then closes the water supply valve 30 . As a result, a part of the diluted water in the tank 13 is discharged from the overflow space A2.

In the second process (water circulation process, step S52) executed after the first process, the control unit 80 operates the pump motor 33 for a predetermined time while the cooling device 40 is stopped and the valve 34 is opened, so that the water is The tank 13 circulates between the ice making portion 11 (including the front and back surfaces of the ice making plate 12). Thereby, the remaining water remaining in the circulation path other than the tank 13 can be conveyed to the tank 13 by flowing the circulating water.

In the third process (residual water drainage process, step S53 ) executed after the second process, the control unit 80 passes the drain pipe by operating the pump motor 33 with the drain valve 21 open and the valve 34 closed. 20 discharges the water in the tank 13 to the outside. When the water level of the tank 13 drops due to the drainage and the distance detected by the distance sensor 22 becomes a preset distance corresponding to the bottom surface 13A of the tank 13 (the height of the bottom surface 13A is detected), the control unit 80 determines that the drainage is completed, The pump motor 33 is stopped, the drain valve 21 is closed, and the third process is stopped. Then, in the third process, the control unit 80 controls the rotational speed of the pump motor 33 so that the height of the water pumped up by the pump 15 becomes the height between the ice making unit 11 and the intermediate unit 19 . Thereby, it can suppress that the water in the tank 13 goes to the ice making part 11, and it can drain more reliably.

In the fourth process (sterilization process, step S54 ) executed after the third process, the control unit 80 operates the UV sterilization device 70 for a predetermined time to control the water in the tank 13 (water remaining in the tank 13 without being drained) ) for sterilization.

As shown in FIG. 10 , the control unit 80 executes the residual water treatment operation every time a predetermined time T11 (for example, 4 hours) elapses in a state where neither the ice making operation nor the deicing operation is performed (in other words, the cooling device 40 is stopped). (1st process, 2nd process, 3rd process, 4th process, steps S51-S54). That is, the control unit 80 periodically performs the residual water treatment operation when the ice making operation and the deicing operation are not performed.

Then, as shown in FIG. 11 , when the power supply of the ice maker 10 is switched from the OFF state to the ON state (YES in step S61 ), the control unit 80 executes the residual water treatment operation (the first process - Fourth process) (step S62). In addition, the user can switch the ON state and the OFF state of the power supply of the ice maker 10 by operating the power switch which the operation part 55 has, for example.

Next, the effects of the present embodiment will be described. The ice maker 10 of the present embodiment includes: an ice maker 11 for producing ice by freezing water; a cooling device 40 for cooling the ice maker 11; a tank 13 for storing water; and a pump 15 including a pump whose rotational speed can be changed The motor 33 is capable of supplying the water in the tank 13 to the ice making unit 11 along with the driving of the pump motor 33; Structure, the control part 80 performs the ice making operation of making ice in the ice making part 11 by operating the cooling device 40 and the pump motor 33, and controls the rotation speed of the pump motor 33 during the ice making operation.

In the above configuration, by driving the pump motor 33 , water (ice making water) can be circulated between the tank 13 and the ice making unit 11 . Furthermore, by increasing or decreasing the rotational speed of the pump motor 33, the circulation amount of the ice-making water between the tank 13 and the ice-making unit 11 can be increased or decreased. In the initial stage of the ice making operation, it is preferable to operate the pump motor 33 at a relatively high rotation speed (high speed V1 ) to increase the circulation amount of the ice making water, thereby efficiently cooling the ice making water in the ice making unit 11 . However, when the ice-making water is sufficiently cold and the circulation of the ice-making water is large, ice is generated in the tank 13 due to the supercooling of the ice-making water, 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 the low speed V3) during the ice making operation, so that the ice making water between the tank 13 and the ice making unit 11 can be made to rotate at a predetermined timing. The amount of circulation is reduced, and the generation of ice floes can be suppressed.

Furthermore, the ice making unit temperature sensor 16 capable of detecting the temperature of the ice making unit 11 is provided, and the control unit 80 performs the following processing during the ice making operation: when the temperature detected by the ice making unit temperature sensor 16 is higher than 0° C. When the predetermined temperature C2 is lower than or equal to the predetermined temperature C2, the rotational speed of the pump motor 33 is lowered, and after a predetermined time has elapsed, the rotational speed of the pump motor 33 is raised.

During the ice-making operation, the ice-making water is cooled, and the temperature of the ice-making unit 11 is lowered along with this. When the rotation speed of the pump motor 33 is lowered in a state where the temperature of the ice making unit 11 is lower than a predetermined temperature (a temperature higher than 0° C.) (the ice making water is sufficiently cold), the ice making in the ice making unit 11 The flow rate of water decreases, and the temperature of the ice making unit 11 further decreases, whereby seed ice tends to be generated in the ice making unit 11 . When a kind of ice is produced, the ice grows with the kind of ice as a core. In addition, when ice exists in the ice making unit 11, the heat exchange efficiency in the ice making unit 11 is lowered, so that it becomes difficult to cool the ice making water and supercooling hardly occurs. Therefore, after the seed ice is formed by reducing the rotational speed of the pump motor 33 (to the low speed V3 ) for a predetermined time, and then increasing the rotational speed of the pump motor 33 (to the medium speed V2 ), it is possible to suppress the foaming Ice production, and faster ice production.

In addition, the control unit 80 is provided with a water temperature sensor 17 capable of detecting the temperature of the water stored in the tank 13, and the control unit 80 performs the following processing during the ice making operation: when the temperature detected by the water temperature sensor 17 is equal to or lower than a predetermined temperature C1 higher than 0°C In the case of , the rotational speed of the pump motor 33 is decreased, and the rotational speed of the pump motor 33 is increased after a predetermined time has elapsed.

During the ice-making operation, the ice-making water that has passed through the ice-making unit 11 is stored in the tank 13 , so the water temperature of the tank 13 follows the temperature of the ice-making water in the ice-making unit 11 . In a state where the water temperature of the tank 13 is equal to or lower than a predetermined temperature (a temperature higher than 0° C.) (a state in which the ice-making water is sufficiently cold), when the rotational speed of the pump motor 33 is lowered, the ice-making water in the ice-making unit 11 is reduced in speed. The flow rate decreases, and the temperature of the ice making unit 11 further decreases, whereby seed ice is likely to be generated in the ice making unit 11 . When a kind of ice is produced, the ice grows with this kind of ice as a nucleus. Then, when ice exists in the ice making unit 11, the heat exchange efficiency in the ice making unit 11 decreases, so that it becomes difficult to cool the ice making water and supercooling hardly occurs. Therefore, by lowering the rotation speed of the pump motor 33 for a predetermined time after seed ice is formed, the rotation speed of the pump motor 33 is increased, thereby suppressing the generation of ice floes and producing ice more quickly.

The pump motor 33 is a DC motor, and when the rotational speed of the pump motor 33 is equal to or lower than a predetermined rotational speed, the control unit 80 determines that the water circulation between the tank 13 and the ice making unit 11 is not normally performed. When scale deposits on the water circulation path between the tank 13 and the ice maker 11 , the water circulation is hindered, and the load acting on the pump motor 33 increases, so the rotation speed of the pump motor 33 decreases. Therefore, the control unit 80 can determine that the circulation of the water between the tank 13 and the ice making unit 11 is not normally performed when the rotational speed is equal to or lower than the predetermined rotational speed.

The pump motor 33 is a DC motor, and 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 normally performed. When scale is deposited on the water circulation path between the tank 13 and the ice maker 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 the predetermined current value, the control unit 80 can determine that the circulation of the water between the tank 13 and the ice making unit 11 is not normally performed.

Further, a distance sensor 22 (a water level sensor) capable of measuring the water level of water stored in the tank 13 is provided, and the ice making unit 11 includes an ice making plate 12 having an ice making surface 12A through which water water flows, and the tank 13 is arranged in Below the ice making plate 12, the control unit 80 performs a process of gradually decreasing the rotational 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.

In the above-described configuration, the water level in the tank 13 is lowered as the ice on the ice making surface 12A grows (increases). In addition, in the process of water flowing downward on the ice making surface 12A, the water may be bounced off by the ice on the ice making surface 12A and scattered, and the larger the ice, the larger the amount of water scattered. Therefore, by gradually reducing the rotational speed of the pump motor 33 as the water level becomes lower, the amount of scattering of water can be reduced, and the water can be returned to the tank 13 more reliably. In addition, by reducing the rotational 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. By reducing the amount of water that is on the circulation path, water savings can be achieved because the water on the circulation path is not used for ice making.

Then, the control unit 80 executes a cleaning operation of circulating water between the tank 13 and the ice making unit 11 by operating the pump motor 33 with the cooling device 40 stopped, and alternately and repeatedly operates the pump motor 33 during the cleaning operation. 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 . In the cleaning operation, by circulating water between the tank 13 and the ice maker 11, the water circulation path can be cleaned. In addition, by repeatedly increasing and decreasing the rotational speed of the pump motor 33 during the cleaning operation, the water can be pulsated in the circulation path, and dirt (scale, etc.) on the circulation path can be efficiently peeled off by the pressure of the water, so it is possible to The water circulation path is cleaned more efficiently.

Further, a pipe 18 for connecting the ice making unit 11 to the pump 15 , a drain pipe 20 leading out from the intermediate portion 19 of the pipe 18 and for draining the water in the tank 13 to the outside, and a drain valve for opening and closing the drain pipe 20 are provided. 21. 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 discharge the water in the tank 13 to the outside through the drain pipe 20. In the operation, in the drainage operation, the rotational speed of the pump motor 33 is controlled so that the height of the water pumped up by the pump 15 becomes the height between the ice making portion 11 and the intermediate portion 19 . By operating the pump 15 , in addition to supplying the water to the ice maker 11 , it is possible to discharge the water in the tank 13 . In addition, since the height (lift) of the water pumped up by the pump 15 during the drainage operation is set to the height between the ice making unit 11 and the intermediate part 19, it is possible to suppress the water in the tank 13 from heading toward the ice making unit 11, and it is possible to Drainage reliably.

Further, the ice making unit 11 for producing ice by freezing water, the cooling device 40 for cooling the ice making unit 11 , the tank 13 capable of storing the water supplied to the ice making unit 11 , and the water disposed in the tank 13 and stored are provided. The distance sensor 22 which can measure the distance to the water surface of the water stored in the tank 13 above. When the water level in the tank 13 becomes high, the distance from the distance sensor 22 to the water surface becomes small. Therefore, the water level of the water in the tank 13 can be detected by measuring the distance from the distance sensor 22 to the water surface. If the ice maker 1 of the comparative example shown in FIG. 8 is configured to detect the water level of the water in the tank 13 using the float switch 2, there is a concern that the float 3 (float) that is in contact with the water may cause the When foreign matter such as scale adheres, the height of the buoy 3 changes and the water level cannot be accurately detected. The distance sensor 22 of the above-mentioned structure can suppress the contact with water, and thus can detect the water level more accurately.

In addition, the float switch fixes the detectable water level and cannot measure the water level linearly. For example, as shown in FIG. 8 , when the float switch 2 capable of detecting only two water levels L11 and L12 is used, it is considered that the work start water level of the ice making operation is set to the water level L11 and the work stop water level is set to the water level L12 , to perform the ice making operation. In this case, since the amount of ice produced is determined by the difference between L11 and L12, the amount of ice produced by the ice making operation is the same every time.

Furthermore, when the float switch is used, after the water level in the tank 13 reaches L11 with the water supply, the water in the tank 13 overflows from the upper end of the vertical wall portion 32 to the overflow space A2 by supplying the water for a predetermined period of time. The water level L13 (overflow water level) at this time is set as the work start water level, and the ice making operation is performed until the work stop water level L12 is reached. In this case, the amount of ice produced is also determined by the difference between L13 and L12, so the amount of ice produced is the same every time. Moreover, since the water in the tank 13 overflows, it is not preferable from the viewpoint of water saving. In the present embodiment, by using the distance sensor 22, the work start water level L2 and the work stop water level L4 can be set at predetermined water levels, and the amount of ice produced by the ice making work can be changed.

In addition, the distance sensor 22 is configured to be able to measure the distance to the water surface by irradiating ultrasonic waves toward the water surface. According to the distance sensor 22 having the above-mentioned configuration, the water level of the water in the tank 13 can be measured by measuring the distance to the water surface using ultrasonic waves. When the distance sensor 22 is configured to irradiate the water surface with laser light, the laser light may be directed toward the water without being reflected on the water surface, and it may be difficult to accurately measure the distance to the water surface. Ultrasonic waves can be reflected more reliably on the water surface, so the distance to the water surface can be measured more reliably.

In addition, the pump 15 is provided with the pump 15 and the control unit 80 . The pump 156 is provided with the pump motor 33 and can supply the ice making unit 11 with water in the tank 13 , and the tank 13 is the water supplied to the ice making unit 11 as the pump motor 33 is driven. In the structure in which the unfrozen water is stored in the tank 13, the control unit 80 performs an ice making operation of making ice in the ice making unit 11 by operating the cooling device 40 and the pump motor 33, and when the distance sensor 22 detects the When the distance to the water surface is the preset work start distance K2, the ice making operation is started, and when the distance to the water surface detected by the distance sensor 22 is the work stop distance K4 greater than the work start distance K2 , stop the ice making operation. During the ice making operation, the water in the tank 13 becomes ice in the ice making part. Therefore, the difference between the work start distance K2 and the work stop distance K4 is proportional to the amount of ice produced in the ice making unit 11 . Therefore, by separately setting the work start distance K2 and the work stop distance K4, the amount of ice produced in the ice making unit 11 can be changed.

In addition, the tank 13 is configured to discharge the water exceeding the overflow water level L1 to the outside of the tank 13 when the water in the tank 13 exceeds a predetermined overflow water level L1, and the water level of the water surface corresponding to the work start distance K2 (Work start water level L2) is lower than overflow water level L1. Since the ice making operation is started at a water level lower than the overflow water level L1, it can be suppressed that the water in the tank 13 exceeds the overflow water level L1 and is discharged during the ice making operation.

Then, the control unit 80 executes the operation when the distance to the water surface measured by the distance sensor 22 is greater than the work stop distance K4, that is, the first abnormal distance K5 or more, or when the distance to the water surface measured by the distance sensor 22 is greater than An error notification process for notifying an error when the job start distance K2 is smaller than the second abnormal distance K6, which is a small value. When the water level in the tank 13 is significantly low (when the water level in the tank 13 is more than or equal to the first abnormal distance K5) or when the water level in the tank 13 is significantly high (when the water level in the tank 13 is significantly lower than the second abnormal distance K6), an error is notified. The abnormality of the water level in the tank 13 can be notified to a worker.

In addition, the ice storage tank 14 (ice storage section) capable of storing the ice produced in the ice making unit 11 is provided, and the ice storage tank 14 is arranged above the ice stored in the ice storage tank 14 and can measure the upper surface of the ice stored in the ice storage tank 14 . The ice storage unit side distance sensor 23 of the distance to the surface 14D. As the amount of ice stored in the ice storage tank 14 increases, the upper surface of the ice becomes higher, so the distance from the ice storage unit side distance sensor 23 to the upper surface of the ice becomes smaller. As a result, by providing the ice storage unit side distance sensor 23, the amount of ice stored in the ice storage tank 14 can be measured. Thereby, ice making can be performed according to the amount of ice stored in the ice storage tank 14 . In addition, 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 .

In addition, a water supply pipe 29 for supplying water from a water supply pipe 31 (an external water source) to the tank 13, a water supply valve 30 for opening and closing the water supply pipe 29, a pipe 18 for connecting the ice maker 11 and the pump 15, The control unit 80 periodically executes the following processes: 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 water supply valve 30 is opened to supply water from the water supply pipe 31 to the tank 13; the second process is performed after the first process, and the pump motor 33 is operated in a state where the cooling device 40 is stopped to make the water flow between the tank 13 and the tank 13. Circulation between the ice making units 11 ; and the third process, which is performed after the second process, discharges the water in the tank 13 to the outside through the drain pipe 20 by operating the pump motor 33 with the drain valve 21 open.

When the ice making operation is performed, the water circulating between the tank 13 and the ice making unit 11 is in a cooled state. On the other hand, when the state in which the ice making operation is not performed continues for a long time, the water temperature of the water remaining on the water circulation path (hereinafter simply referred to as the circulation path) between the tank 13 and the ice making unit 11 increases, It is considered that it is the case where bacteria easily multiply. By performing the first to third processes, the water remaining in the circulation path can be washed with the supplied water and discharged. By regularly executing such first to third processes, even when the ice making operation is not performed for a long time, the inside of the circulation path can be maintained in a cleaner state.

Then, when the power supply of the ice maker 10 is switched from the OFF state to the ON state, the control unit 80 executes the first process, the second process, and the third process. If the power supply of the ice maker 10 is turned off for a long time with water remaining in the circulation path, the water remaining in the circulation path may not be performed due to reasons such as the ice making operation, the above-mentioned periodic residual water treatment operation, and the like. When the water temperature rises, it is considered that the bacteria can easily multiply. Therefore, when the power supply is switched to the ON state, by periodically executing the first to third processes in this order, the inside of the circulation path can be brought into a clean state before the ice making operation is performed.

In addition, the UV sterilization device 70 is provided for sterilizing the water in the tank 13 by irradiating ultraviolet rays to the water in the tank 13 , and the control unit 80 executes the operation of the UV sterilizing device 70 after the third process to sterilize the water in the tank 13 . The water is subjected to the fourth treatment of sterilization. The water in the tank 13 that is not drained by the third treatment can be sterilized by the UV sterilizer. Thereby, the inside of the tank 13 can be brought into a cleaner state. In addition, in this embodiment, when the water purifier which removes chlorine is provided in the water supply pipe 31, it becomes easier for bacteria to multiply in the residual water. Therefore, it is particularly preferable to perform the above-described first to fourth treatments 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 the drawings, and the following embodiments, for example, are also included in the technical scope of the present invention.

(1) In the above-described embodiment, the downflow ice maker was exemplified, but the form of the ice maker is not limited to the downflow. The technique described in this specification can also be applied to the ice maker of another type (for example, a unit type) in which water circulates between a tank and an ice making part.

(2) In the above-described embodiment, the use of ultrasonic waves as the distance sensor 22 was exemplified, but the present invention is not limited to this. As the distance sensor 22, it is also possible to use a configuration that measures the distance to the water surface by irradiating the water surface with laser light. In addition, when the laser beam is difficult to reflect on the water surface, the water surface may be measured by floating a reflecting member (for example, a cylindrical buoy) with a high light reflectivity on the water surface and irradiating the reflecting member with the laser beam. distance structure. Moreover, as a water level sensor which measures the water level in the tank 13, you may use the water level sensor other than a distance sensor.

(3) In the additional water supply process (step S4 in FIG. 5 ) of the above-described embodiment, for example, the water level of the tank 13 may be supplied to the same height as the overflow water level L1 , the water level may be set as the work start water level, and the water level may be set higher than this water level. The water level lower than the predetermined value is set as the work stop water level. In addition, the water level at this time may be set as the work start water level, and the water level lower than the water level by a predetermined value may be set as the work stop water level without executing the additional water supply process. In addition, the control unit 80 may supply water to the water level of the tank 13 to the same height as the overflow water level L1 in the additional water supply process, and then supply the water for a predetermined period of time, set the water level (overflow water level) at this time as the work start water level, and set the A water level lower than this water level by a predetermined value is set as the work stop water level.

(4) In the additional water supply process (step S4 in FIG. 5 ), when the water level of the tank 13 is supplied to the same height as the overflow water level L1, after the water level reaches the overflow water level L1 (work start water level), The water supply is continued until the temperature of the ice making water becomes a certain low temperature (until the temperature detected by the ice making section temperature sensor 16 and the water temperature sensor 17 is equal to or lower than a predetermined temperature (eg, 5° C.)). When the pump 15 is operated to cool the ice-making water, the water will be scattered while the water is flowing down on the ice-making surface 12A. When the water is scattered, the water level of the tank 13 drops, so ice making is performed from the water level lower than the work start water level to the work end water level, and ice smaller than the desired size is produced. By continuing to supply water until the ice-making water reaches a relatively low temperature (a temperature close to 0° C.), the ice-making water can be cooled and the amount of water scattered in the ice-making plate can be replenished, so that the water level in the tank 13 can be reduced By maintaining the overflow water level L1, which is the work start water level, the reduced amount of water from the work start water level to the work stop water level can be turned into ice, so that ice of a desired size can be more reliably produced.

(5) In the above-described embodiment, the ice making operation is started by the user operating the operation unit 55 as an example, but the present invention is not limited to this. For example, the control unit 80 may be set in a case where the distance to the upper surface of the ice (the amount of ice stored in the ice storage tank 14 ) measured by the ice storage unit side distance sensor 23 is equal to or greater than a predetermined distance set in advance (storage). When the ice in the ice tank 14 is less than or equal to a predetermined amount), the ice making operation is started. That is, the control unit 80 may start the ice making operation based on the amount of ice stored in the ice storage tank 14 .

(6) The control unit 80 may execute an error notification process for notifying an error when the above-mentioned condition FE3 or condition FE4 is satisfied for a predetermined time during the deicing operation and the cleaning operation.

(7) The predetermined temperatures C1, C2, C3, C4, C5 and the predetermined times T1, T3, T4, T5, T6, T7, T8, T9, and T10 in the above-mentioned embodiment are not limited to the illustrated numerical values, and can be appropriately set. Certainly.

(8) The control unit 80 may execute only the first to third processes without executing the fourth process in the above-mentioned residual water treatment operation.

Description of reference numerals

10...Ice maker, 11...Ice making section, 12...Ice making plate, 12A...Ice making surface, 13...Tank, 14...Ice storage tank (ice storage section), 14D...Top of ice stored in the ice storage section Surface, 15...Pump, 16...Ice making unit temperature sensor, 17...Water temperature sensor, 18...Pipe connecting the ice making unit to the pump, 19...Middle of piping, 20...Drain pipe, 21...Drain pipe Closed drain valve, 22...Distance sensor (water level sensor), 23...Ice storage side distance sensor, 29...Water supply pipe, 30...Water supply valve, 33...Pump motor, 40...Cooling device, 58...Water surface (stored in tank water surface), 70...UV sterilization device, 80...control unit, K2...work start distance, K4...work stop distance, K5...first abnormal distance, K6...second abnormal distance, L1...overflow water level.

Claims (11)

1. An ice maker, comprising:

an ice making part for making ice by freezing water;

a cooling device that cools the ice making portion;

a tank to store water;

a pump which is provided with a pump motor capable of changing the rotation speed and can supply water in the tank to the ice making part along with the driving of the pump motor; and

a control part for controlling the operation of the display device,

the tank is configured to store unfrozen water in the water supplied to the ice making part,

the control portion performs an ice making operation of making ice in the ice making portion by operating the cooling device and the pump motor, and controls a rotation speed of the pump motor in the ice making operation.

2. The ice maker of claim 1,

the ice maker is provided with an ice making unit temperature sensor capable of detecting the temperature of the ice making unit,

the control portion performs the following processing during the ice making job: the rotation speed of the pump motor is made low when the temperature detected by the ice making unit temperature sensor is a predetermined temperature higher than 0 ℃ or lower, and the rotation speed of the pump motor is made high after a predetermined time has elapsed.

3. The ice-making machine of claim 1,

the ice maker is provided with a water temperature sensor capable of detecting the temperature of water stored in the tank,

the control portion performs the following processes during the ice making job: the rotation speed of the pump motor is lowered when the temperature detected by the water temperature sensor is a predetermined temperature higher than 0 ℃ or lower, and the rotation speed of the pump motor is raised after a predetermined time has elapsed.

4. The ice maker according to any one of claims 1 to 3,

the pump motor is a DC motor and,

the control unit determines that circulation of water between the tank and the ice making unit is not normally performed when the rotation speed of the pump motor is equal to or less than a predetermined rotation speed.

5. The ice maker according to any one of claims 1 to 4,

the pump motor is a DC motor and,

the control unit determines that the circulation of water between the tank and the ice making unit is not normally performed when a current value of the pump motor is equal to or greater than a predetermined current value.

6. The ice maker according to any one of claims 1 to 5,

the ice maker is provided with a water level sensor capable of measuring the water level of the water stored in the tank,

the ice making section has an ice making plate having an ice making surface to which water flows down,

the tank is disposed under the ice making plate,

the control portion performs the following processes during the ice making job: the rotation speed of the pump motor is gradually decreased as the water level measured by the water level sensor is decreased.

7. The ice maker as in any of claims 1-6,

the control part performs a washing operation of circulating water between the tank and the ice making part by operating the pump motor in a state of stopping the cooling device,

the process of making the rotation speed of the pump motor low and the process of making the rotation speed of the pump motor high are alternately repeated during the cleaning operation.

8. The ice maker according to any one of claims 1 to 7,

the ice maker is provided with:

a pipe connecting the ice making unit and the pump;

a drain pipe which is drawn out from an intermediate portion of the pipe and discharges water in the tank to the outside; and

a drain valve for opening and closing the drain pipe,

the ice making part is disposed at a position higher than the pump,

the control unit performs a water discharge operation of discharging water in the tank to the outside through the water discharge pipe by operating the pump motor in a state where the water discharge valve is opened,

in the water discharge operation, the control portion controls the rotation speed of the pump motor such that the height of the water pumped up by the pump is a height between the ice making portion and the intermediate portion.

9. The ice maker according to any one of claims 1 to 6,

the ice maker is provided with:

a water supply pipe for supplying water from an external water source to the tank;

a water supply valve for opening and closing the water supply pipe;

a pipe connecting the ice making unit and the pump;

a drain pipe which is drawn out from an intermediate portion of the pipe and discharges water in the tank to the outside; and

a drain valve for opening and closing the drain pipe,

the control unit periodically executes:

a first process of supplying water from the external water source to the tank by opening the water supply valve;

a second process, executed after the first process, of circulating water between the tank and the ice making portion by operating the pump motor in a state in which the cooling device is stopped; and

and a third process, executed after the second process, of discharging the water in the tank to the outside through the drain pipe by operating the pump motor in a state where the drain valve is opened.

10. The ice-making machine of claim 9,

when the power supply of the ice maker is switched from an off state to an on state, the control unit executes the first process, the second process, and the third process.

11. The ice maker of claim 9 or 10,

the ice maker is provided with a UV sterilization device which irradiates ultraviolet rays to the water in the tank to sterilize the water in the tank,

the control unit executes a fourth process of sterilizing the water in the tank by operating the UV sterilization device after the third process is executed.

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