JP7341903B2 - ice machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ice making machine.

BACKGROUND ART Conventionally, as an ice making machine, for example, the one described in Patent Document 1 is known. Patent Document 1 describes a configuration in which water stored in a tank (ice-making water tank) is supplied to an ice-making section (ice-making plate) by a pump (circulation pump). In Patent Document 1, water that is not frozen in the ice making section is configured to return to the tank. Therefore, by operating the pump, it is possible to circulate water (ice-making water) between the tank and the ice-making section. Furthermore, in Patent Document 1, a water level sensor is provided to detect the water level in the tank, and the ice making operation is configured to end when the water level in the tank reaches a predetermined height. .

Patent No. 5448618

By the way, a float switch equipped with a float is generally used as a water level sensor for detecting the water level in a tank. When using a float switch, there is a concern that foreign matter such as scale may adhere to the float that is in contact with water. If scale adheres to the float, the height of the float may change, leading to concerns that the water level may not be detected accurately.

The present invention was completed based on the above circumstances, and an object of the present invention is to provide an ice making machine that can more accurately detect the water level in a tank.

As a means for solving the above problems, the ice making machine disclosed herein includes an ice making section that produces ice by freezing water, a cooling device that cools the ice making section, and a cooling device that supplies ice to the ice making section. A distance sensor is provided above the water stored in the tank and is capable of measuring the distance to the water surface of the water stored in the tank. It has particular characteristics.

As the water level in the tank rises, the distance from the distance sensor to the water surface becomes smaller. Therefore, the water level in the tank can be detected by measuring the distance from the distance sensor to the water surface. If the configuration is such that a float switch is used to detect the water level in the tank, foreign matter such as scale may adhere to the float that is in contact with the water, causing the height of the float to increase. There are concerns that the water level may change and the water level may not be detected accurately. Since the distance sensor configured as described above can suppress contact with water, it can detect the water level more accurately.

Further, the distance sensor may be 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 configured as described above, the water level in the tank can be measured by measuring the distance to the water surface using ultrasonic waves. If the distance sensor were configured to irradiate a laser onto the water surface, the laser may not be reflected on the water surface and may head into the water, making it difficult to accurately measure the distance to the water surface. Since ultrasonic waves can be reflected more reliably on the water surface, the distance to the water surface can be measured more reliably.

The pump includes a pump motor and is capable of supplying water in the tank to the ice making unit as the pump motor is driven, and a control unit, and the tank is configured to Of the water supplied to the ice making section, unfrozen water is stored in the tank, and the control section controls the production of ice in the ice making section by operating the cooling device and the pump motor. Further, when the distance to the water surface detected by the distance sensor reaches a preset driving start distance, the ice making operation is started, and the ice making operation is performed by the distance sensor. The ice making operation may be stopped when the detected distance to the water surface becomes an operation stop distance that is greater than the operation start distance.

During ice-making operation, water in the tank turns into ice in the ice-making section. Therefore, the difference between the operation start distance and the operation stop distance is proportional to the amount of ice produced in the ice making section. Therefore, by setting the operation start distance and operation stop distance, respectively, it is possible to change the amount of ice produced in the ice making section.

Further, the tank is configured such that when the water in the tank exceeds a predetermined overflow water level, the water exceeding the overflow water level can be drained to the outside of the tank, and the water in the tank exceeds a predetermined overflow water level. The water level of the corresponding water surface may be lower than the overflow water level. Since the ice-making operation is started at a water level lower than the overflow water level, it is possible to suppress a situation in which water in the tank is drained in excess of the overflow water level during the ice-making operation.

Further, the pump motor is configured to be able to change its rotational speed, the ice making unit includes an ice making plate having an ice making surface through which water flows, and the tank is disposed below the ice making plate. The control unit may perform a process of gradually decreasing the rotational speed of the pump motor as the distance to the water surface measured by the distance sensor increases during the ice-making operation. .

In the above configuration, as the ice on the ice-making surface grows (becomes larger), the water level in the tank decreases (the distance to the water surface measured by the distance sensor increases). Furthermore, in the process of water flowing down the ice-making surface, the water may be repelled by the ice on the ice-making surface and scatter, and the larger the ice, the greater the amount of water scattered. Therefore, by gradually lowering the rotational speed of the pump motor as the water level becomes lower, the amount of water splashed can be reduced and water can be returned to the tank more reliably. Furthermore, by lowering 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. Since the water in the circulation path is not used for making ice, water can be saved by reducing the amount of water used.

In addition, when the distance to the water surface measured by the distance sensor becomes equal to or greater than a first abnormal distance, which is a value larger than the operation stop distance, or a value smaller than the operation start distance, When the distance becomes less than or equal to a second abnormal distance, an error notification process for notifying an error may be executed. Alerts an error when the water level in the tank becomes significantly low (below the first abnormal distance) or when the water level in the tank becomes significantly high (below the second abnormal distance) This allows workers to be notified of abnormal water levels in the tank.

Further, an ice storage unit capable of storing ice produced by the ice making unit and an ice storage unit disposed above the ice stored in the ice storage unit and measuring the distance to the upper surface of the ice stored in the ice storage unit and an ice storage unit side distance sensor that can perform the following steps. As the amount of ice stored in the ice storage section increases, the top surface of the ice becomes higher, so the distance from the ice storage section side distance sensor to the top surface of the ice becomes smaller. As a result, by providing the ice storage unit side distance sensor, the amount of ice stored in the ice storage unit can be measured. This makes it possible to make ice according to the amount of ice stored in the ice storage section.

According to the present invention, it is possible to provide an ice making machine that can more accurately measure the water level in a tank.

A diagram showing an ice making machine according to Embodiment 1 Perspective view showing the ice making section Cross-sectional view showing an enlarged view of the vicinity of the storage pipe in the tank Block diagram showing the electrical configuration of the ice maker Flowchart showing the processing of the control unit related to ice-making operation Flowchart showing processing of the control unit related to deicing operation Flowchart showing processing of the control unit related to cleaning operation Diagram showing an ice maker as a comparative example Block diagram showing the relationship between each component of the ice maker according to Embodiment 2 Schematic diagram of ice making mechanism and cooling device Cross-sectional view showing the ice making mechanism Schematic diagram of ice making mechanism, ice making water flow path, and ice storage mechanism Plan view showing the tank (with the water inlet at position P1) Plan view showing the tank (with the water inlet at position P2) Cross-sectional view showing the tank (corresponds to the diagram cut along the XV-XV line in Figure 14) Cross-sectional view showing a check valve trap

<Embodiment 1>
Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 8. In this embodiment, a flowing-down type ice maker 10 is illustrated as an ice maker. As shown in FIG. 1, the ice making machine 10 includes a plurality of ice making units 11 that produce ice by freezing water, and a cooling unit that cools the ice making units 11 (more specifically, each ice making plate 12 included in the ice making unit 11). A device 40, a tank 13 capable of storing water supplied to the ice making section 11, an ice storage tank 14 (ice storage section) capable of storing ice produced in the ice making section 11, and a tank in the ice making section 11. 13.

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

The ice making section 11 includes a plurality of ice making plates 12, a water sprinkling pipe 24, and a water sprinkling guide 25. The ice-making plate 12 is provided in a vertical position. In the plurality of ice-making plates 12, a meandering evaporation pipe 44 (a part of the cooling device 40) is provided between a pair of ice-making plates 12, 12 arranged oppositely. As shown in FIG. 2, the ice-making plate 12 has a plurality of ice-making surfaces 12A extending in the vertical direction and a plurality of protrusions 12B extending in the vertical direction. The plurality of ice-making surfaces 12A are lined up in the horizontal direction, and adjacent ice-making surfaces 12A are separated by protrusions 12B. The ice making surface 12A is constituted by the surface of the ice making plate 12 on the opposite side to the evaporation tube 44. A water sprinkler pipe 24 (water sprinkler) is provided for each pair of ice-making plates 12, 12. The ice-making water sent from the pump 15 to the water sprinkling pipe 24 is sprinkled onto each ice-making surface 12A by the water sprinkling pipe 24. The ice-making water sprinkled from the water sprinkling pipe 24 is guided to each ice-making surface 12A by a water-sprinkling guide 25, and then flows down each ice-making surface 12A.

As shown in FIG. 1, the cooling device 40 includes a compressor 41, a condenser 42, an expansion valve 43, an evaporation pipe 44, and a fan 46. The compressor 41, condenser 42, expansion valve 43, and evaporation pipe 44 are connected by a refrigerant pipe 45 filled with refrigerant. Compressor 41 compresses refrigerant gas. The condenser 42 cools and liquefies the compressed refrigerant gas by blowing air from a fan 46 . The expansion valve 43 expands the liquefied refrigerant. The evaporation pipe 44 (evaporator) evaporates the liquefied refrigerant expanded by the expansion valve 43 to cool the ice-making plate 12 . In this way, the compressor 41, condenser 42, expansion valve 43, evaporation pipe 44, and refrigerant pipe 45 constitute a refrigerant circulation cycle (refrigeration circuit) for cooling the ice-making plate 12. The cooling device 40 also includes a dryer 47 for removing moisture mixed into the refrigeration circuit. The ice-making section temperature sensor 16 is provided in the refrigerant pipe 45 near the outlet of the evaporation tube 44, and is capable of detecting the temperature of the ice-making plate 12. Note that, for example, a thermistor can be used as the ice making section temperature sensor 16, but the present invention is not limited thereto.

The cooling device 40 also includes a bypass pipe 49 for supplying refrigerant gas (hot gas) compressed by 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. , is provided. By opening the hot gas valve 50, refrigerant gas (hot gas) can be supplied from the compressor 41 to the evaporation tube 44, and the evaporation tube 44 can be heated. That is, the cooling device 40 has a function 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 body 26 that is open upward, and a lid 27 that covers the opening of the tank body 26. Ice-making water used for ice-making is stored in the internal space of the tank body 26 . The tank body section 26 is arranged below the ice making section 11. Note that the lid body 27 is not provided at a location directly below the ice making section 11 in the tank body section 26. Further, a drainboard 28 is interposed between the tank main body 26 and the ice making section 11. As a result, water flowing down from the ice making section 11 passes through the drainboard 28 and is stored in the tank 13.

Further, a water supply pipe 52 (water supply pipe) is provided between the pair of ice-making plates 12, 12. The water supply pipe 52 is connected to the water pipe 31 via the water supply pipe 29 and the water supply valve 30. Thereby, by opening the water supply valve 30, 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). Further, of the ice-making water flowing down the ice-making surface 12A, unfrozen water is stored in the tank 13. In other words, the tank 13 is configured to store unfrozen water out of the ice-making water supplied to the ice-making section 11 . Thereby, by operating the pump 15, it is possible to circulate ice-making water between the tank 13 and the ice-making section 11. Note that in this specification, ice-making water is not limited to water used for ice-making, but includes water that circulates between the tank 13 and the ice-making section 11.

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

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

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

The distance sensor 22 is placed above the water stored in the tank 13 and measures the distance to the water surface of the tank 13 by emitting ultrasonic waves toward the water surface of the tank 13. It is an ultrasonic sensor that can More specifically, the distance sensor 22 includes an irradiation section that irradiates ultrasonic waves and a reception section that receives ultrasonic waves reflected by the surface of water in the tank 13. It is possible to measure the distance from the distance sensor 22 to the water surface based on the time it takes for the water to return to the receiving section. Since the distance from the distance sensor 22 to the water surface is linked to the water level in the tank 13, the distance sensor 22 can be used as a water level sensor that can measure the water level stored in the tank 13. By using the distance sensor 22 as a water level sensor, the water level can be detected linearly.

The distance sensor 22 is housed in a housing tube 35 provided in a lid 27 covering the tank 13, as shown in FIG. By housing the distance sensor 22 in the housing tube 35, measurement errors of the distance sensor 22 due to changes in ambient temperature can be reduced. The accommodation tube 35 is a circular tube that is long in the vertical direction, and is arranged so as to pass through the lid body 27. Further, the accommodation pipe 35 is opened downward, and its lower end (open end) is arranged to face the bottom surface 13A of the tank 13 with a slight gap therebetween. Therefore, in the tank 13, the water level inside the accommodation pipe 35 is the same as the water level outside the accommodation pipe 35. Furthermore, a notch 36 is formed at the open end (lower end) of the accommodation tube 35 . By providing such a notch 36, it is possible to suppress the situation in which the water ripples within the accommodation tube 35, and it is possible to further improve the accuracy of water level measurement.

Further, an air hole 37 is formed in the accommodation tube 35 at a position higher than the lid 27, which communicates the inside of the accommodation tube 35 with the outside (the outside of the tank 13). The air hole 37 is arranged at a higher position than the lid body 27. When the water level in the accommodation tube 35 rises, the air in the accommodation tube 35 is discharged to the outside through the air hole 37 by the amount of the rise in the water level.

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

Further, inside the housing tube 35, a first sound absorbing material 38 is provided to surround the distance sensor 22 from all sides in the horizontal direction, and a second sound absorbing material 39 is further provided to surround the first sound absorbing material 38. There is. The first sound absorbing material 38 and the second sound absorbing material 39 are made of different materials. For example, the first sound absorbing material 38 is made of a rubber material, and the second sound absorbing material 39 is made of a foam material. By surrounding the distance sensor 22 with the first sound absorbing material 38 and the second sound absorbing material 39, it is possible to suppress the situation in which the distance sensor 22 receives external noise, and to further increase the measurement accuracy of the distance sensor 22. I can do it.

Further, a water temperature sensor 17 (see FIG. 1) that can detect the temperature of water stored in the tank 13 is provided between the pump 15 and the distance sensor 22. The water temperature sensor 17 is attached to the lid 27 and is provided in such a way that it comes into contact with the water in the tank 13 . Note that, for example, a thermistor can be used as the water temperature sensor 17, but the present invention is not limited thereto.

The ice storage tank 14 stores the ice made in the ice making section 11, and is arranged below the ice making section 11 as shown in FIG. There is. The user takes out the made ice from the ice storage tank 14 and uses it. Note that the drainboard 28 described above constitutes a part of the ice discharge pipe 51. The drainboard 28 is provided in such a manner that it slopes downward toward the ice inlet 14A in the ice storage tank 14. Thereby, the ice that has fallen onto the drainboard 28 is sent toward the entrance 14A. The ice storage section side distance sensor 23 is an ultrasonic sensor provided on the upper wall section 14B that constitutes the ice storage tank 14. The configuration is such that it is possible to measure the distance to the top surface 14D.

In other words, the ice storage unit side distance sensor 23 is capable of measuring the amount of ice stored in the ice storage tank 14. Specifically, as the amount of ice in the ice storage tank 14 increases, the top surface of the ice becomes higher, so the distance from the ice storage unit side distance sensor 23 to the top surface of the ice decreases, and the amount of ice in the ice storage tank 14 decreases. Since the upper surface of the ice becomes lower, the distance from the ice storage unit side distance sensor 23 to the upper surface of the ice becomes larger.

Next, the electrical configuration of the ice maker 10 will be explained. The ice maker 10 includes a control section 80, as shown in FIG. The control section 80 includes a cooling device 40 (more specifically, a compressor 41, a fan 46, a hot gas valve 50), a distance sensor 22, an ice storage section distance sensor 23, a pump motor 33, an ice making section temperature sensor 16, and a water temperature sensor. The sensor 17, water supply valve 30, drain valve 21, valve 34, clock section 53 (timer), and storage section 54 are electrically connected. The ice maker 10 also includes an operation section 55 consisting of a switch that can be operated by a user, and a display section 56 (for example, a liquid crystal panel) that can display error messages and the like. In other words, the display unit 56 is a notification unit that can notify the operator of errors. The operation section 55 and the display section 56 are each electrically connected to the control section 80.

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

The control unit 80 is capable of performing ice-making operation, de-icing operation, and cleaning operation, respectively. The ice-making operation is an operation in which ice is produced in the ice-making section 11 by operating the pump motor 33 while operating the cooling device 40 to cool the ice-making plate 12 . The deicing operation refers to operating the cooling device 40 to heat the ice making plate 12 while operating the pump motor 33 and water supply valve 30 to remove the produced ice from the ice making surface 12A of the ice making section 11. It's driving. The cleaning operation is an operation in which water is circulated between the tank 13 and the ice making section 11 by operating the pump motor 33 while the cooling device 40 is stopped, thereby cleaning the ice making water circulation path. be.

Further, the control unit 80 can control the rotation speed of the pump motor 33. In this embodiment, the pump motor 33 is exemplified to have five rotational speeds: high speed V1, medium speed V2, low speed V3, high speed for cleaning V4A, and low speed for cleaning V4B. Note that V1>V2>V3, V4A>V1, and V4A>V4B, but the values of each rotational speed can be set as appropriate. Furthermore, in the following description of the present embodiment, "the control unit 80 opens the water supply valve 30 to supply tap water into the tank 13" may be referred to as "water supply".

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

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

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

Further, when the pump motor 33 is operated, the water level in the tank 13 is lowered because the water in the tank 13 is sent to a circulation path of ice-making water other than the tank 13 (piping 18, ice-making section 11, etc.). For this reason, the control unit 80 operates the pump motor 33 at high speed V1 and after a predetermined time T1 (for example, 15 seconds) has elapsed ("YES" in step S3), the water level in the tank 13 is lowered to the operation start water level. Water is supplied until it reaches L2 (step S4, additional water supply processing). That is, the tank 13 is replenished with water that has been reduced from the tank 13 as the pump motor 33 operates. Further, the control unit 80 calculates a value obtained by adding a predetermined value K3 (predetermined distance) to the operation start distance K2 at the time when the additional water supply process is completed (when the water level in the tank 13 returns to the operation start water level L2). It is stored in the storage unit 54 as the operation stop distance K4. The ice-making operation is stopped when the value of the distance sensor 22 reaches the operation stop distance K4 (details will be described later). Note that the operation stop distance K4 may be stored in the storage unit 54 at a time before the start of the ice-making operation (for example, at the time when the operation start distance K2 is input).

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

When the temperature of the ice-making water decreases, heat exchange between the ice-making water and the ice-making plate 12 is suppressed, so the temperature of the ice-making plate 12 decreases. After the water level in the tank 13 reaches the operation start water level L2 (after step S4), the control unit 80 controls the pump motor 33 when the following condition FA1 or condition FA2 is satisfied ("YES" in step S5). is set to low speed V3 (step S6). The following predetermined temperatures C1 and C2 are values larger than 0°C and near 0°C, and can be set as appropriate. Preferably, the predetermined temperature C1 is set, for example, in a range of 1°C to 5°C, and the predetermined temperature C2 is set, for example, in a range of 2°C to 10°C. In other words, the control unit 80 sets the pump motor to low speed V3 before the temperature of the ice-making water reaches 0° C. (before ice is generated on the ice-making surface 12A).
Condition FA1: Detected temperature of the water temperature sensor 17 that measures the water temperature of the tank 13 ≦ predetermined temperature C1 (for example, 2.5°C)
Condition FA2: Detected temperature of ice making section temperature sensor 16 ≦ predetermined temperature C2 (for example, 5°C)

When the pump motor 33 is set from high speed V1 to low speed V3, the amount of ice-making water circulated is reduced, and the amount of ice-making water flowing down the ice-making surface 12A is reduced, so that the temperature of the ice-making surface 12A is further reduced. As a result, ice nuclei (seed ice) are likely to be formed at a location on the ice making surface 12A corresponding to the evaporator tube 44 (a location where the temperature is particularly low on the ice making surface 12A). Furthermore, by setting the pump motor 33 at low speed V3, cooling of the ice-making water is suppressed, so that it is possible to suppress a situation in which the ice-making water is overcooled, and a situation in which ice fluff is generated in the tank 13 can be suppressed.

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

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

That is, the control unit 80 sets the pump motor 33 to the low speed V3 and then, after a predetermined period of time has elapsed, performs a process of increasing the rotational speed of the pump motor 33 (setting it to the medium speed V2). After seed ice is generated on the ice making surface 12A, the ice making water freezes while flowing down the surface of the seed ice. As a result, as time passes, the half-moon-shaped ice 57 (see FIG. 1) that protrudes from the ice-making surface 12A grows. Note that when ice 57 is generated on the ice making surface 12A, heat exchange between the ice making surface 12A and the ice making water is suppressed by the ice 57, so that the cooling rate of the ice making water is reduced. Therefore, after seed ice is generated, even if the rotational speed of the pump motor 33 is increased, fluff ice is difficult to generate.

Further, as the ice 57 grows on the ice making surface 12A, the water level in the tank 13 decreases. After step S8, the control unit 80 performs rotational speed reduction processing (step S9). In the rotation speed reduction process, as the distance to the water surface measured by the distance sensor 22 increases (as the water level in the tank 13 measured by the water level sensor decreases), the rotation speed of the pump motor 33 is gradually lowered. As the ice on the ice making surface 12A becomes larger, the ice making water supplied to the ice making plate 12 becomes more likely to scatter due to being repelled by the ice. Since the scattered ice-making water does not return to the tank 13, the amount of water used for ice-making decreases, and the ice becomes smaller than desired. Therefore, as the ice grows, the rotational speed of the pump motor 33 is gradually lowered to reduce the amount of ice-making water circulated, and it is possible to prevent the ice-making water from scattering. In addition, in the rotational speed reduction process, the rotational speed of the pump motor 33 may be lowered continuously or may be lowered stepwise.

Then, when the water level in the tank 13 reaches the operation stop water level L4 ("YES" in step S10), the control unit 80 stops the operation when the distance to the water surface detected by the distance sensor 22 is greater than the operation start distance K2. When the distance K4 is reached), the pump motor 33 is stopped to stop the ice-making operation and shift to the de-icing operation. Note that, instead of step S10, the control unit 80 determines that the "state in which the water level in the tank 13 is below the operation stop level L4" has continued for a predetermined time T9 (for example, 20 seconds) (the water level in the tank 13 is lower than the operation stop level L4). The ice making operation may be stopped by stopping the pump motor 33, and the ice making operation may be shifted to the deicing operation, on the condition that the water level is stabilized below L4. In this way, the influence of changes in water level due to undulation of the water surface in the tank 13 can be suppressed, so that even when the ice making operation is repeated, the size of the ice made can be the same each time.

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

Note that a possible cause of the water not being properly circulated between the tank 13 and the ice-making section 11 is that scale is deposited in the ice-making water circulation path. In addition, in the circulation path, scale is particularly likely to precipitate at locations where the flow velocity is slow (such as the end of the water sprinkling pipe 24 or the end of the water sprinkling guide 25). Therefore, when the condition FE1 or the condition FE2 is satisfied, the control unit 80 may perform a cleaning operation as an error handling process. Further, the control unit 80 may stop the operation of the ice maker 10 as an error handling process when the condition FE1 or the condition FE2 is satisfied.

Further, the control unit 80 executes an error notification process for notifying an error when the following condition FE3 or condition FE4 is satisfied for a predetermined time during the ice making operation. In the error notification process, the control unit 80 displays, for example, an error message on the display unit 56 to notify the user that "the water level in the tank is abnormal."
Condition FE3: Distance to the water surface measured by distance sensor 22≧first abnormal distance K5
Condition FE4: Distance to the water surface measured by distance sensor 22 ≦ second abnormal distance K6
Note 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 or the cleaning operation.

The first abnormal distance K5 is a value larger than the operation stop distance K4. The second abnormal distance K6 is a value smaller than the driving start distance K2. Therefore, if the distance to the water surface measured by the distance sensor 22 exceeds the first abnormal distance K5, this corresponds to a significant drop in the water level in the tank 13. 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. The fact that the distance to the water surface measured by the sensor 22 is less than or equal to the second abnormal distance K6 corresponds to a significant rise in the water level in the tank 13.As shown in FIG. The abnormal distance K6 is a value corresponding to a water level L6 higher than the overflow water level L1. Therefore, the reason why the above condition FE4 is satisfied is that the tank 13 is not drained normally via the overflow space A2. Or, the distance sensor 22 may not be installed in the correct position, and the water level in the tank 13 may not be measured correctly.

Next, the processing of the control unit 80 during the deicing operation will be explained. In the deicing operation, as shown in FIG. 6, the control unit 80 operates the pump motor 33 with the drain valve 21 open to drain the water in the tank 13 to the outside through the drain pipe 20. A drainage operation (wastewater treatment) is executed (step S21). When the water level in the tank 13 decreases with 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 starts. The unit 80 determines that drainage is complete, and stops the pump motor 33 and closes the drainage valve 21 to stop the drainage operation.

In the ice-making operation of the down-flow 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 in the tank 13. ). In other words, immediately after the ice-making operation is completed, the water in the tank 13 is concentrated water with a high concentration of impurities. Such concentrated water causes scale to form in the circulation path. For this reason, it is more preferable to perform the drainage operation immediately after the ice-making operation to drain the concentrated water as described above. In addition, in the drainage operation, the control unit 80 controls the rotational speed of the pump motor 33 (at least higher than the low speed V3 described above) so that the height of the water pumped by the pump 15 is at the height between the ice making unit 11 and the intermediate unit 19. low speed). Thereby, it is possible to suppress the situation in which the water in the tank 13 to be drained goes toward the ice making section 11, and the water can be drained more reliably.

Next, the control unit 80 stops the fan 46 and opens the hot gas valve 50 (step S22). Thereby, refrigerant gas (hot gas) is supplied from the compressor 41 to the evaporator tube 44, and the evaporator tube 44 (and by extension, the ice-making plate 12) can be heated. Furthermore, the control unit 80 opens the water supply valve 30 to cause tap water to flow down onto the back surface of the ice-making plate 12 via the water supply pipe 52 (step S23). As a result, the ice-making plate 12 is heated by the tap water and hot gas, and the portion of the ice 57 in contact with the ice-making surface 12A melts, so that the ice 57 is peeled off from the ice-making surface 12A (de-icing). After the de-icing ice falls onto the drainboard 28, it is stored in the ice storage tank 14. Moreover, the tap water flowing down the back surface of the ice-making plate 12 falls into the tank 13, so that the water level in the tank 13 rises. When the water level in the tank 13 rises and reaches the operation start water level L2 (the distance to the water surface detected by the distance sensor 22 becomes the operation start distance K2) ("YES" in step S24), the control unit 80: The water supply valve is closed to stop water supply (step S25).

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

Thereafter, when the temperature of the ice-making plate 12 rises to a certain extent and the following condition FB1 is satisfied ("YES" in step S26), the control unit 80 operates the pump motor 33 at medium speed V2 (step S27). For example, in step S27, the pump motor 33 is operated at medium speed V2 for a predetermined time T5 (for example, 15 seconds) and then stopped, and after the predetermined time T6 (for example, 30 seconds), the pump motor 33 is operated at medium speed V2, for example. After operating for a predetermined time T7 (for example, 15 seconds), it is stopped. In this way, by flowing ice-making water onto the ice-making surface 12A while the temperature of the ice-making plate 12 has risen to a certain extent, deicing of the ice can be promoted.
Condition FB1: Detection temperature of ice making section temperature sensor 16≧predetermined temperature C4 (for example, 4°C)
Note that when the portion of the ice 57 in contact 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. Therefore, as described above, after the contact portion of the ice 57 with the ice-making surface 12A melts, the pump motor 33 is operated to flow ice-making water onto the ice-making surface 12A, and the ice 57 is knocked off by the force of the water. By doing so, deicing can be promoted. However, when refrigerant gas (hot gas) is supplied from the compressor 41 to the evaporator tube 44, the inlet side of the evaporator tube 44 (the side closer to the hot gas valve 50, corresponding to the upper part of the ice-making plate 12) is the outlet of the evaporator tube 44. side (corresponding to the ice-making section temperature sensor 16 side and the lower part of the ice-making plate 12). In other words, the higher the ice 57 on the ice making surface 12A, the faster it melts at the contact portion with the ice making surface 12A. Therefore, in the present embodiment, first, the pump motor 33 is operated at medium speed V2 for a predetermined time T5 to deice the ice 57 located at the upper part (approximately the upper half) of the ice making surface 12A, which is relatively easy to melt. Thereafter, by allowing a predetermined time T6 to elapse, the contact portion of the ice 57 at the bottom of the ice making surface 12A with the ice making surface melts, and then by operating the pump motor 33 at medium speed V2 for a predetermined time T7, the ice at the bottom is melted. I am trying to de-ice 57.

Then, after the following condition FB2 is satisfied ("YES" in step S28), if a predetermined time T8 (for example, 60 seconds) has elapsed ("YES" in step S29), the control unit 80 controls the ice-making surface 12A to It is determined that the ice has been removed, the deicing operation is stopped, and the ice making operation is started. Note that the predetermined temperatures C4 and C5 can be set as appropriate, but the predetermined temperatures C4 and C5 are set at a temperature higher than 0° C., and the predetermined temperature C5 is set at a temperature higher than the predetermined temperature C4.
Condition FB2: Detection temperature of ice making unit temperature sensor 16≧predetermined temperature C5 (for example, 9°C)

Note that the control unit 80 operates until the distance (corresponding to the amount of ice stored in the ice storage tank) to the upper surface 14D of ice measured by the ice storage unit side distance sensor 23 reaches a predetermined distance K7 ( Ice making operation and deicing operation are repeatedly performed until the ice storage tank reaches a predetermined amount of ice. Further, since this predetermined distance K7 (the amount of ice in the ice storage tank) can be set as appropriate, it is possible to adjust the amount of ice in the ice storage tank 14. In addition, when performing the ice making operation for the second time or later, the control unit 80 may omit the water supply process (the process of supplying tap water up to the operation start water level L2) performed before the ice making operation.

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

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

Further, in the above embodiment, the cleaning operation is executed on condition that the cycle of ice making operation and deicing operation has been executed a predetermined number of times. However, the present invention is not limited to this. The concentration of impurities contained in the water in the tank 13 is measured by a sensor, and when the concentration of impurities exceeds a predetermined value, the control unit 80 executes the cleaning operation after the deicing operation. good. Note that the higher the concentration of impurities in water, the higher the electrical conductivity. Therefore, this embodiment may include an electrical conductivity sensor capable of measuring electrical conductivity. Such an electrical conductivity sensor is electrically connected to the control unit 80, and the electrical conductivity sensor measures the electrical conductivity of water, and the control unit 80 controls whether the measured electrical conductivity is equal to or higher than a predetermined value. The cleaning operation may be performed when the impurity concentration reaches a predetermined value or higher. Note that the water temperature sensor 17 is configured by, for example, a thermistor housed in a metal case 17A (outer shell portion of the water temperature sensor 17, see FIG. 3). When the water temperature sensor 17 having such a configuration is used, it may include an electrode 48 disposed in contact with the water in the tank 13, as shown by the two-dot chain line in FIG. The electrode 48 is spaced apart from the case 17A, and the electrode 48 and the case 17A are electrically connected to the control unit 80. The control unit 80 energizes both the electrode 48 and the case 17A to flow a current into the water between the electrode 48 and the case 17A, and measures the electrical resistance of the water, thereby increasing the electricity of the water in the tank 13. Conductivity can be measured. That is, one electrode (for example, a positive electrode) of a pair of electrodes forming the electrical conductivity sensor may be configured by the electrode 48, and the other electrode (for example, a negative electrode) may be configured by the case 17A.

Next, the effects of this embodiment will be explained. The ice making machine 10 of this embodiment includes an ice making section 11 that makes ice by freezing water, a cooling device 40 that cools the ice making section 11, a tank 13 that stores water, and a rotation speed that can be changed. The pump 15 includes a pump motor 33 and is capable of supplying water in the tank 13 to the ice making unit 11 as the pump motor 33 is driven, and a control unit 80. Of the water supplied to the ice-making section 11, unfrozen water is stored in the tank 13. An ice-making operation for producing ice is executed, and the rotation speed of the pump motor 33 is controlled 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 section 11. Furthermore, by increasing or decreasing the rotational speed of the pump motor 33, the amount of ice-making water circulated between the tank 13 and the ice-making section 11 can be increased or decreased. At the beginning of the ice-making operation, it is preferable to operate the pump motor 33 at a relatively high rotational speed (high speed V1) to increase the amount of ice-making water circulated so that the ice-making water can be cooled efficiently in the ice-making section 11. However, if the ice-making water is sufficiently cooled and the amount of ice-making water circulated continues to be large, there is a concern that ice fluff will be generated in the tank 13 due to overcooling of the ice-making water, which will impede the circulation of the ice-making water. In the above configuration, since the control unit 80 can lower the rotational speed of the pump motor 33 (low speed V3) during the ice-making operation, the ice-making water is circulated between the tank 13 and the ice-making unit 11 at a predetermined timing. The amount can be reduced, and the generation of cotton ice can be suppressed.

The control unit 80 also includes an ice-making unit temperature sensor 16 capable of detecting the temperature of the ice-making unit 11, and controls the control unit 80 to set the temperature detected by the ice-making unit temperature sensor 16 to a predetermined temperature C2 higher than 0° C. during ice-making operation. When the rotation speed of the pump motor 33 is below, the rotation speed of the pump motor 33 is lowered, and after a predetermined period of time has elapsed, the rotation speed of the pump motor 33 is increased.

In the ice-making operation, the ice-making water is cooled, and the temperature of the ice-making section 11 decreases accordingly. When the rotational speed of the pump motor 33 is lowered when the temperature of the ice making section 11 is below a predetermined temperature (a temperature higher than 0° C.) (the ice making water is sufficiently cold), the flow rate of the ice making water in the ice making section 11 is reduced. As the temperature of the ice making section 11 decreases further, seed ice is more likely to be generated in the ice making section 11. When seed ice forms, ice grows using the seed ice as a nucleus. If there is ice in the ice making section 11, the heat exchange efficiency in the ice making section 11 decreases, making it difficult to cool the ice making water and making it difficult to cause supercooling. For this reason, the rotation speed of the pump motor 33 is lowered (set to low speed V3), and after a predetermined period of time has elapsed to form seed ice, the rotation speed of the pump motor 33 is increased (set to medium speed V2). , it is possible to produce ice faster while suppressing the generation of cotton ice.

The control unit 80 also includes a water temperature sensor 17 capable of detecting the temperature of water stored in the tank 13, and controls the control unit 80 to set the temperature detected by the water temperature sensor 17 to a predetermined temperature C1 higher than 0° C. during ice making operation. When the rotation speed of the pump motor 33 is below, the rotation speed of the pump motor 33 is lowered, and after a predetermined period of time has elapsed, the rotation speed of the pump motor 33 is increased.

During the ice-making operation, the ice-making water that has passed through the ice-making section 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 section 11. When the rotation speed of the pump motor 33 is lowered when the water temperature in the tank 13 is below a predetermined temperature (a temperature higher than 0° C.) (the ice-making water is sufficiently cold), the flow rate of ice-making water in the ice-making section 11 decreases. However, as the temperature of the ice making section 11 further decreases, seed ice is more likely to be produced in the ice making section 11. When seed ice forms, ice grows using the seed ice as a nucleus. If there is ice in the ice making section 11, the heat exchange efficiency in the ice making section 11 decreases, making it difficult to cool the ice making water and making it difficult to cause supercooling. For this reason, the rotation speed of the pump motor 33 is lowered, and after a predetermined period of time has elapsed to form seed ice, the rotation speed of the pump motor 33 is increased, while suppressing the generation of fluff ice. Manufacturing can be done faster.

Further, the pump motor 33 is a DC motor, and the control unit 80 controls the water circulation between the tank 13 and the ice making unit 11 to be normal when the rotation speed of the pump motor 33 becomes less than a predetermined rotation speed. It is determined that this has not been done. If scale is deposited on the water circulation path between the tank 13 and the ice-making section 11, it will impede the water circulation and increase the load acting on the pump motor 33, resulting in a decrease in the rotational speed of the pump motor 33. Therefore, the control unit 80 can determine that the water circulation between the tank 13 and the ice making unit 11 is not being normally performed when the rotational speed becomes equal to or lower than the predetermined rotational speed.

Further, the pump motor 33 is a DC motor, and the control unit 80 controls the water circulation between the tank 13 and the ice making unit 11 to be normal when the current value of the pump motor 33 is equal to or higher than a predetermined current value. It is determined that this has not been done. If scale is deposited on the water circulation path between the tank 13 and the ice making section 11, it will impede the water circulation and the load acting on the pump motor 33 will increase, so the current of the pump motor 33 will increase. Therefore, when the current value of the pump motor 33 exceeds a predetermined current value, the control unit 80 determines that water circulation between the tank 13 and the ice making unit 11 is not being performed normally. I can do it.

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

In the above configuration, as the ice on the ice making surface 12A grows (becomes larger), the water level in the tank 13 becomes lower. Furthermore, in the process of water flowing down the ice-making surface 12A, the water may be repelled by the ice on the ice-making surface 12A and scatter, and the larger the ice, the greater the amount of water scattered. Therefore, by gradually lowering the rotational speed of the pump motor 33 as the water level becomes lower, the amount of water splashed can be reduced and the water can be returned to the tank 13 more reliably. Further, by lowering 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. Since the water in the circulation path is not used for making ice, water can be saved by reducing the amount of water used.

Furthermore, the control unit 80 executes a cleaning operation in which water is circulated between the tank 13 and the ice making unit 11 by operating the pump motor 33 while the cooling device 40 is stopped. , a process of lowering the rotational speed of the pump motor 33, and a process of increasing the rotational speed of the pump motor 33 are alternately repeated. During the cleaning operation, by circulating water between the tank 13 and the ice making section 11, the water circulation path can be cleaned. In the cleaning operation, by repeatedly increasing and decreasing the rotational speed of the pump motor 33, water can be pulsated in the circulation path, and dirt (scale, etc.) in the circulation path can be efficiently removed by the pressure of the water. This allows the water circulation path to be cleaned more efficiently.

Further, a pipe 18 connecting the ice making section 11 and the pump 15, a drain pipe 20 drawn out from the intermediate part 19 of the pipe 18 and for draining water in the tank 13 to the outside, and a drain pipe 20 for opening and closing the drain pipe 20. The ice making section 11 is arranged at a higher position than the pump 15, and the control section 80 operates the pump motor 33 with the drain valve 21 open, thereby draining the drain pipe 20. A drainage operation is performed in which the water in the tank 13 is drained to the outside through the pump 15. In the drainage operation, the height of the water pumped up by the pump 15 is set to the height between the ice making section 11 and the intermediate section 19. The rotation speed of the pump motor 33 is controlled. By operating the pump 15, in addition to supplying water to the ice making section 11, it becomes possible to drain water in the tank 13. The height (lifting height) of the water pumped up by the pump 15 during the drainage operation is set to be the height between the ice making section 11 and the intermediate section 19, so that the water in the tank 13 reaches the ice making section 11. It is possible to prevent the situation from occurring and ensure that drainage can be carried out reliably.

Also, an ice making unit 11 that produces ice by freezing water, a cooling device 40 that cools the ice making unit 11, a tank 13 that can store water supplied to the ice making unit 11, and a tank 13 that can store water supplied to the ice making unit 11. A distance sensor 22 is provided above the water stored in the tank 13 and capable of measuring the distance to the surface of the water stored in the tank 13. As the water level in the tank 13 rises, the distance from the distance sensor 22 to the water surface becomes smaller. Therefore, the water level in the tank 13 can be measured 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 in the tank 13 using the float switch 2, ) If foreign matter such as scale adheres to the float 3, the height of the float 3 may change, and there is a concern that the water level may not be detected accurately. Since the distance sensor 22 configured as described above can suppress contact with water, it can detect the water level more accurately.

Furthermore, the detectable water level of the float switch is fixed, and the water level cannot be measured linearly. For example, as shown in FIG. 8, when using a float switch 2 that can detect only two water levels L11 and L12, the operation start water level of ice making operation is set to water level L11, the operation stop water level is set to water level L12, It is conceivable to perform an ice-making operation. In this case, the amount of ice made is determined by the difference between L11 and L12, so the amount of ice made in each ice making operation is the same each time.

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

Further, 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 configuration, the water level in the tank 13 can be measured by measuring the distance to the water surface using ultrasonic waves. If the distance sensor 22 is configured to irradiate a laser onto the water surface, the laser may not be reflected on the water surface and may head into the water, making it difficult to accurately measure the distance to the water surface. Since ultrasonic waves can be reflected more reliably on the water surface, the distance to the water surface can be measured more reliably.

The pump 15 includes a pump motor 33 and is capable of supplying water in the tank 13 to the ice making unit 11 as the pump motor 33 is driven, and a control unit 80. 13 is configured such that unfrozen water out of the water supplied to the ice making section 11 is stored in the tank 13, and the control section 80 controls the ice making section 11 by operating the cooling device 40 and the pump motor 33. Furthermore, when the distance to the water surface detected by the distance sensor 22 reaches a preset operation start distance K2, the ice making operation is started and the distance When the distance to the water surface detected by the sensor 22 becomes an operation stop distance K4 that is greater than the operation start distance K2, the ice making operation is stopped. In the ice-making operation, water in the tank 13 turns into ice in the ice-making section. Therefore, the difference between the operation start distance K2 and the operation stop distance K4 is proportional to the amount of ice produced in the ice making section 11. Therefore, by setting the operation start distance K2 and the operation stop distance K4, the amount of ice produced in the ice making section 11 can be changed.

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

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

Additionally, there is an ice storage tank 14 (ice storage unit) capable of storing ice produced in the ice making unit 11, and an upper surface 14D of the ice stored in the ice storage tank 14, which is disposed above the ice stored in the ice storage tank 14. An ice storage section side distance sensor 23 capable of measuring the distance to. 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 (accumulation height) can be measured. This makes it possible to make ice according to the amount of ice stored in the ice storage tank 14. Further, the control unit 80 may display the amount of ice measured by the ice storage unit side distance sensor 23 on the display unit 56.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS. 9 to 16. In this embodiment, an auger-type ice maker 210 is illustrated as the ice maker. As shown in FIG. 9, the ice making machine 210 includes an ice making mechanism 220, a cooling device 240, an ice making water flow path 250, an ice storage mechanism 270, and a control section 280. The ice making mechanism 220 makes ice. The cooling device 240 is a device for cooling the ice making mechanism 220 (specifically, the cylinder 221 of the ice making section 220A). The ice-making water flow path 250 allows ice-making water to flow. The ice storage mechanism 270 stores made ice. The control unit 280 controls each unit based on a control program, detection results of various sensors, and the like. Note that the ice-making water in this embodiment is not limited to water used for ice-making, but includes all water flowing through the ice-making water channel 250, such as water used for washing.

As shown in FIG. 10, the cooling device 240 includes a compressor 241, a condenser 242, an expansion valve 243, and an evaporation pipe 244, which are connected by a refrigerant pipe 245. Compressor 241 compresses refrigerant gas. The condenser 242 cools and liquefies the compressed refrigerant gas by blowing air from a fan 246 . The expansion valve 243 expands the liquefied refrigerant. Evaporation tube 244 is wound around the outer surface of cylinder 221. The evaporation pipe 244 evaporates the liquefied refrigerant expanded by the expansion valve 243 to cool the cylinder 221 . In this way, the compressor 241, condenser 242, expansion valve 243, evaporation pipe 244, and refrigerant pipe 245 constitute a refrigerant circulation cycle (refrigeration circuit) for cooling the cylinder 221 (ice making section 220A). be done. The cooling device 240 further includes a fan 246, a dryer 247, and a temperature sensor 248. The dryer 247 removes moisture mixed into the refrigeration circuit. The temperature sensor 248 is provided at the outlet of the evaporator tube 244 in the refrigerant tube 245 and between the condenser 242 and the dryer 247, and detects the temperature of the refrigerant.

As shown in FIG. 11, the ice making mechanism 220 includes an ice making section 220A that makes ice by freezing water, a driving section 220B, and a connecting section 220C. The drive unit 220B supplies power (specifically, rotational force to an auger 222, which will be described later) to the ice making unit 220A to drive the ice making unit 220A. The connecting portion 220C mechanically connects the ice making portion 220A and the driving portion 220B, and transmits the power of the driving portion 220B to the ice making portion 220A.

As shown in FIG. 11, the ice making section 220A includes a cylinder 221 (ice making tube, cooling tube), an auger 222, a molding member 223 (fixed blade, compression head), a heat insulating material 224, a cutter 225, and an ice discharging tube. It includes a pipe 226 and a seal portion 227 (mechanical seal). The cylinder 221 is made of metal (for example, stainless steel) and has a hollow cylindrical shape, and an evaporation tube 244 is wound around the outer surface of the cylinder 221 . Two openings (a water supply port 221A and a drain port 221B) are provided in the side wall of the cylinder 221 below the evaporation pipe 244. Ice-making water is supplied into the cylinder 221 from the water supply port 221A. Moreover, the ice-making water in the cylinder 221 is discharged to the outside of the cylinder 221 from the drain port 221B. The heat insulating material 224 covers the outer surface of the evaporation tube 244 and enhances the cooling effect.

As shown in FIG. 11, the auger 222 has an elongated rod shape as a whole, and is inserted vertically into the internal space of the cylinder 221 so that the elongated direction of extension is along the central axis of the cylinder 221. The auger 222 includes a spiral ice cutting blade 222A in a portion overlapping with the evaporation tube 244 when viewed from the side. The ice-shaving blade 222A protrudes from the rod-shaped main body of the auger 222 toward the inner surface 221F of the cylinder 221, and its protruding length is such that it does not slightly reach the inner surface 221F of the cylinder 221. The ice cutting blade 222A scrapes off ice attached to the inner surface 221F of the cylinder 221.

The molded member 223 is disposed inside and above the cylinder 221, as shown in FIG. The molded member 223 has a substantially cylindrical shape, and the upper part 222B of the auger 222 is inserted into an internal space surrounded by a cylindrical inner wall. Moreover, the molded member 223 has a wall surface between it and the inner surface 221F of the cylinder 221 so that an ice passing path 223A that penetrates vertically is formed. The ice transported by the auger 222 is pushed into the ice passing path 223A and compressed into a columnar shape.

The cutter 225 is arranged above the molded member 223, as shown in FIG. The cutter 225 cuts the ice compressed and molded by the molding member 223 into a predetermined length. The ice discharge pipe 226 is arranged above the molding member 223 so as to cover the cutter 225. The ice cut by the cutter 225 passes through the ice discharge pipe 226 and is stored in an ice storage tank 271, which will be described later.

As shown in FIG. 11, the seal portion 227 is arranged inside the cylinder 221 and includes a sealing body 227A and a fixture 227B. The sealing body 227A is made of ceramics or hard resin, and fills the gap between the outer surface of the rod-shaped main body of the auger 222 and the upper part of the housing 220C2, which will be described later, to stop ice-making water. The fixture 227B is disposed above the sealing body 227A, and presses and fixes the sealing body 227A against the outer surface of the main body of the auger 222. Thereby, a space surrounded by the outer surface of the auger 222, the sealing body 227A, the upper part of the housing 220C2, and the inner surface 221F of the cylinder 221 constitutes a water storage section S that can store ice-making water. The water supply port 221A and the drain port 221B provided in the cylinder 221 are provided at the bottom of the water storage portion S, specifically, at a position overlapping with the sealing body 227A in a side view. The seal portion 227 rotates together with the auger 222, with the seal 227A sliding against the top of the housing 220C2. Therefore, due to sliding, a portion of the sealing body 227A may be worn away, and the abrasion powder may be generated in the water storage portion S as dirt.

As shown in FIG. 11, the drive section 220B is arranged below the ice making section 220A. The drive unit 220B includes a motor, a gear system, and an output shaft 220B1. When the motor is driven to rotate, power is transmitted through the gear system, and the output shaft 220B1 rotates.

As shown in FIG. 11, the connecting portion 220C includes a coupling 220C1 (shaft joint) and a housing 220C2. The coupling 220C1 has a hollow cylindrical shape, and the lower end of the auger 222 that engages with the spline and the upper end of the output shaft 220B1 are fixed therein. When the output shaft 220B1 rotates, the auger 222 rotates integrally with the coupling 220C1.

As shown in FIG. 12, the ice-making water flow path 250 includes a tank 260 capable of storing water supplied to the ice-making section 220A, a water supply pipe 251, a water storage section S in the cylinder 221, and a first drain pipe 252. , a drain pump 253 , a water pipe 254 , a second drain pipe 255 , a main drain pipe 258 , and a check valve trap 257 . Tank 260 has a substantially box shape and stores ice-making water in its internal space. The water supply pipe 251 is connected to the tank 260 and the water storage section S to communicate them. Ice-making water in the tank 260 is supplied into the cylinder 221 through the water supply pipe 251 so that the water level in the tank body 261 and the water level in the cylinder 221 (water storage section S) are equally balanced. The first drain pipe 252 is connected to the drain port 221B of the water storage section S and the drain pump 253. In order to discharge the ice-making water from the water storage section S, the drain pump 253 sucks the ice-making water from the first drain pipe 252 and discharges it to the water pipe 254 . The water pipe 254 is connected to the drain pump 253 and the tank 260 to communicate with them. The second drain pipe 255 is connected to a tank 260 (specifically, a drain section 262 that is an overflow pipe), and discharges ice-making water to the outside.

As shown in FIGS. 13 to 15, the tank 260 includes a tank body portion 261, a drainage portion 262, a lid body 263, a distance sensor 264 (water level sensor), and a first sterilizer 265 (UV sterilization lamp). , a stepping motor 266. The tank main body portion 261 has a substantially box shape with an upward opening, and stores ice-making water in an internal space. The drainage section 262 is an overflow pipe, and is disposed vertically on the outer circumference of the tank body section 261. One end of the drain section 262 communicates with the upper part of the tank body section 261, and the other end is connected to the second drain pipe 255. When the water level of the ice-making water in the tank body 261 becomes high and reaches a water level that communicates with the drainage part 262 (exceeds the overflow water level), the ice-making water in the tank body 261 overflows and overflows into the drainage part 262. The lid body 263 covers the upper part of the tank body part 261 and the drain part 262. The distance sensor 264 is housed in a housing portion 263D provided in the lid 263, as shown in FIG. The housing portion 263D has a cylindrical shape that is opened downward. Further, an air hole 237 is formed in the wall portion constituting the housing portion 263D, which communicates the inside of the housing portion 263D with the outside (the outside of the tank 13). That is, the distance sensor 264 is placed above the water stored in the tank 260. The distance sensor 264 is, for example, an ultrasonic sensor, and is configured to be able to detect the water level of ice-making water in the tank body 261 by measuring the distance K22 to the water surface 260A of water stored in the tank 260. It becomes. By using an ultrasonic sensor as the distance sensor 264, the water level can be detected linearly.

The first sterilizer 265 is provided on the lid 263 and sterilizes the ice-making water in the tank body 261 by irradiating ultraviolet rays or deep ultraviolet rays from an LED lamp to the ice-making water. Note that if the drainage part 262 is placed outside the outer circumference of the tank body 261, the pipe-shaped drainage part 262 will block the light emitted from the LED lamp, and the ice-making water in the tank body 261 will be blocked. As the irradiation light becomes difficult to reach some parts of the body, the sterilization effect decreases. For this reason, in this embodiment, such a decrease in the sterilizing effect is prevented by arranging the drainage section 262 on the outer periphery of the tank main body section 261.

As shown in FIGS. 13 and 14, the lid body 263 is provided with a water inlet 263A and a water inlet 263B. Ice-making water is supplied into the tank body 261 from an external water pipe through the water inlet 263A. Further, a water injection valve is disposed between the water pipe and the water injection port 263A, and the control unit 280 controls the water injection valve to adjust the supply of ice-making water. A water pipe 254 is connected to the water port 263B. As shown in FIGS. 13 and 14, the water inlet 263B is provided so that its position within the plane of the lid body 263 can be slid. The stepping motor 266 is arranged on the lid body 263 so as to be adjacent to the water inlet 263B, and moves the water inlet 263B from position P1 (the position shown in FIG. 13) to position P2 (the position shown in FIG. 14) or from position P2. Move to position P1. The position of the water inlet 263B can be easily moved by the stepping motor 266. Moreover, by providing the stepping motor 266 on the lid body 263, there is no need to provide a separate installation location for the stepping motor 266, and space can be saved. The water inlet 263B (263B-P1 in FIG. 13) located at position P1 is located above the tank body 261, and the ice-making water passed from the water pipe 254 to the water inlet 263B is poured into the tank body 261. Ru. On the other hand, the water inlet 263B (263B-P2 in FIG. 14) located at position P2 is located vertically above the drainage part 262, and the ice-making water that has passed from the water pipe 254 to the water inlet 263B is injected into the drainage part 262. be done.

As shown in FIG. 12, the check valve trap 257 is provided in the main drain pipe 258 downstream of the second drain pipe 255 in the drainage direction. Note that the check valve trap 257 may be provided in the second drain pipe 255. The check valve trap 257 has a rubber valve 257A, as shown in FIG. , right to left). Thereby, backflow of waste water can be suppressed, and a situation where the ice-making water in the tank 260 is contaminated can be avoided. Further, since the check valve trap 257 can prevent air from entering the second drain pipe 255 from the main drain pipe 258, it is possible to prevent foreign odor, bacteria, etc. from entering from the outside.

As shown in FIG. 12, the ice storage mechanism 270 includes an ice storage tank 271 (ice bin), a third drain pipe 273, an ice storage unit side distance sensor 275 (ice storage height sensor), and a second sterilizer 277. As shown in FIG. 12, the ice storage tank 271 communicates with the ice discharge pipe 226, and is capable of storing ice produced by the ice making mechanism 220. The user takes out the manufactured ice from the ice storage tank 271 and uses it. The third drain pipe 273 is connected to the bottom of the ice storage tank 271 and discharges ice-making water generated in the ice storage tank 271 when the ice melts. The ice storage unit side distance sensor 275 is arranged on the upper wall of the ice storage tank 271. That is, the ice storage section side distance sensor 275 is arranged above the ice stored in the ice storage tank 271 (ice storage section). The ice storage section side distance sensor 275 is, for example, an ultrasonic sensor, and is configured to be able to measure the distance K21 to the upper surface 271A of ice stored in the ice storage tank 271 (see the two-dot chain line in FIG. 12). ing. In other words, the ice storage unit side distance sensor 275 is capable of detecting the height of ice accumulation (the amount of ice) in the ice storage tank 271. The second sterilizer 277 is arranged on the upper wall of the ice storage tank 271, and sterilizes the ice in the ice storage tank 271 by irradiating ultraviolet rays or deep ultraviolet rays from an LED lamp to the ice in the ice storage tank 271.

The third drain pipe 273 is connected to the second drain pipe 255, as shown in FIG. The above-described check valve trap 257 is provided in the main drain pipe 258 on the downstream side in the drain direction from the connection portion between the second drain pipe 255 and the third drain pipe 273. Thereby, it is possible to avoid a situation in which the ice in the ice storage tank 271 is contaminated due to the backflow of wastewater, and it is also possible to prevent foreign odor, bacteria, etc. from flowing in from the outside.

The control unit 280 is mainly composed of, for example, a CPU, and is incorporated into the main board of the ice making mechanism 220. The control unit 280 controls the cooling device 240, the drainage pump 253, and the stepping motor 266 based on the built-in control program, the detection results of each sensor (distance sensor 264, ice storage section distance sensor 275, temperature sensor 248, etc.), and the like. control etc.

Next, the operation of ice maker 210 will be explained. The control unit 280 can switch between ice-making operation, washing operation, and drainage operation. The control unit 280 controls the water level in the tank body 261 to predetermined reference water levels set in advance (specifically, a first reference water level 261a, a second reference water level 261b, and a third reference water level 261c shown in FIG. 15). ). The first reference water level 261a is the water level at which the water injection valve is closed by the control unit 280 and the supply of ice-making water is stopped during ice-making operation. The second reference water level 261b is lower than the first reference water level 261a, and is the water level at which the water injection valve is opened by the control unit 280 and ice-making water is supplied into the tank body 261 during ice-making operation. Further, the third reference water level 261c is higher than the first reference water level 261a and is the same as the overflow water level of the drainage section 262. The third reference water level 261c is determined when ice-making water is supplied from the tank body 261 to the water storage section S in the cylinder 221, and when the water levels in the tank body 261 and the water storage section S become equal, the molded member 223 is completely submerged. The water level is set to

First, ice making operation will be explained. When the ice-making operation is started, the distance sensor 264 detects the water level in the tank body 261 (the distance from the distance sensor 264 to the water surface in the tank body 261). If the water level is less than the first reference water level 261a, the control unit 280 opens the water injection valve, and ice-making water is supplied from the water pipe into the tank body 261 through the water injection port 263A. During ice-making operation, when the first reference water level 261a is detected by the distance sensor 264, the water injection valve is closed and the supply of ice-making water is stopped, and when the second reference water level 261b is detected, the water injection valve is opened again. Ice making water is provided.

The first reference water level 261a and the second reference water level 261b can be set arbitrarily, and the water level of the ice-making water in the water storage section S and, by extension, the ice quality can be adjusted by these set values. For example, when the water level of the ice making water in the water storage section S is relatively high, soft ice containing more water is made, and conversely, when the water level is relatively low, hard ice containing less water is made. Ru. In other words, by including the distance sensor 264, the ice maker 210 of this embodiment can appropriately set the water level in the tank body 261 and, furthermore, the water level in the water storage section S based on the measurement results of the distance sensor 264. The quality of ice produced can be adjusted. Note that the distance sensor 264 of this embodiment can suppress situations in which it comes into contact with water, as in the first embodiment, so compared to the case where a water level sensor that comes into contact with water (such as a float switch) is used, the distance sensor 264 can reduce the water level. can be detected more accurately.

When ice-making water is stored in the water storage section S, the inner surface 221F (ice-making surface) of the side wall of the cylinder 221 becomes immersed in the ice-making water in the water storage section S. When the cooling device 240 is driven to cool the cylinder 221, ice-making water freezes on the inner surface 221F of the side wall of the cylinder 221. As a result, a thin layer of ice adheres to the inner surface 221F of the side wall of the cylinder 221. Then, when the drive unit 220B is driven and the auger 222 is rotated, the ice adhering to the inner surface 221F of the cylinder 221 is scraped off by the ice cutting blade 222A. The scraped fine ice is transported upward by the rotation of the auger 222, pushed into the ice passing path 223A of the molding member 223, and compressed and molded. The molded ice is cut by a cutter 225 to produce ice. The ice that has been made is stored in the ice storage tank 271, and when the ice accumulation height (the amount of ice) detected by the ice storage unit side distance sensor 275 reaches a predetermined accumulation height, the ice making operation is stopped. When the ice in the ice storage tank 271 is used and the ice accumulation height becomes lower than a predetermined accumulation height, the control unit 280 restarts the ice making operation. Since the predetermined accumulation height can be set as appropriate, the amount of ice in the ice storage tank 271 can be adjusted as appropriate. Further, the ice accumulation height measured by the ice storage section side distance sensor 275 may be displayed on a display section (not shown). Thereby, it is possible to prevent the user from opening the ice storage tank 271 to check the amount of ice in the ice storage tank 271, and it is possible to keep the inside of the ice storage tank 271 in a cleaner state.

Further, the control unit 280 can also perform the ice-making operation based on the temporal change in the height of ice accumulation in the ice storage tank 271 (how much ice is reduced). An example will be described in which a plurality of heights L21 to L23 (L21>L22>L23) are set in advance as shown in FIG. 12. Note that the difference between the heights L21 and L22 and the difference between the heights L22 and L23 are set to the same value, for example. If the accumulated height of ice in the ice storage tank 271 reaches the height L22 within a predetermined time T21 (for example, 1 hour) after the accumulated height of the ice reaches the height L21, the control unit 280 controls the amount of ice used (the degree of decrease). ) is determined to be large, ice-making operation is performed until the height reaches L21, and if the height does not reach L22 within the predetermined time T21, it is determined that the amount of ice used is small, and ice-making operation is performed until the height reaches L22. Stop. Then, if the accumulated height of ice in the ice storage tank 271 reaches the height L23 within a predetermined time T21 after reaching the height L22, the control unit 280 performs the ice making operation until the height reaches the height L22. Thereafter, if the height reaches L23 within a predetermined time T21, it is determined that the amount of ice used continues to be large, and the ice making operation is performed until the height reaches L21.

In this way, the amount of ice in the ice storage tank 271 can be adjusted as appropriate depending on the usage status of the ice. In other words, if the amount of ice used (decreased amount) is large, increasing the amount of ice in the ice storage tank 271 can prevent the situation of ice shortage; If so, it is possible to save energy by stopping the ice-making operation. Furthermore, if a large amount of ice is stored in the ice storage tank 271 in a situation where the amount of ice used is small, arching will occur where the ice that has been stored for a long time will become ice blocks, and when ice is used, ice blocks will be Although it will be necessary to crush it, such a situation can be suppressed.

Next, the cleaning operation of this embodiment will be explained. In the cleaning operation, the ice making water circulation path R1 in the ice making machine 210 can be cleaned. In the cleaning operation, first, the distance sensor 264 detects the water level in the tank body 261, and if the water level is less than the third reference water level 261c, the control unit 80 opens the water injection valve, and water is supplied from the water pipe through the water injection port 263A. Ice-making water is supplied into the tank body 261. Further, the control unit 280 drives the drain pump 253, and the stepping motor 266 sets the position of the water inlet 263B to P1. As a result, the ice-making water flow path 250 is configured by the tank main body 261, the water supply pipe 251, the water storage section S, the first drain pipe 252, the drain pump 253, the water pipe 254, the water inlet 263B at position P1, and the tank main body 261. A circulating path R1 (see FIG. 12) is formed. This allows the ice-making water to circulate through the circulation path R1, thereby making it possible to clean the circulation path R1. The circulation cleaning is performed for a predetermined period of time, and the cleaning effect is enhanced by repeating driving and stopping of the drain pump 253 multiple times. Furthermore, when the drive unit 220B is driven during circulation cleaning, the auger 222 rotates, making it possible to clean the inside of the cylinder 221 more effectively.

Next, the operation of the ice maker 210 during the drain operation will be described. When the drain pump 253 is driven and the stepping motor 266 moves the water inlet 263B to P2, the ice-making water is drained from the drain section 262 to the outside. When the water level in the tank body 261 decreases and the distance sensor 264 detects the preset height of the bottom of the tank 260, the control unit 280 determines that all the water in the tank 260 has been drained, and the drain pump 253 will be stopped. For example, abrasion powder generated by abrasion of a part of the sealing body 227A is generated as dirt in the water storage part S, but such dirt can also be discharged by the drain pump 253 through the drain port 221B. becomes. As shown in FIG. 11, the drain port 221B is provided at the bottom of the water storage section S so as to overlap the sealing body 227A in a side view, so dirt generated from the sealing body 227A is absorbed by the suction force of the drain pump 253. It is easily excreted.

According to the ice maker 210 configured as described above, dirt on the ice making water generated in the water storage section S is discharged by the drain pump 253 and can be easily removed. Moreover, since the presence or absence of drainage can be switched by driving the drainage pump 253, there is no need to separately provide a drainage valve, and it is possible to avoid a situation where dirt adheres to the drainage valve and causes drainage failure. Furthermore, by connecting the water pipe 254 to the drain pump 253 and the tank 260 (specifically, the tank main body part 261), in the ice-making water flow path 250, the tank 260 (tank main part 261), the water supply pipe 251, and the water storage part Since the circulation path R1 is formed which connects S, the drainage pump 253, the water pipe 254, and the tank 260 (tank main body 261) in this order, the ice-making water flow path 250 can be circulated and cleaned. Through circulation cleaning, the inside of the cylinder 221, the molded member 223, and the tank 260, where dirt tends to remain, can be easily cleaned, and the cleaning power against dirt generated in the ice-making water channel 250 can be increased.

Moreover, the ice making machine 210 can switch whether or not to form the circulation path R1 in the ice making water flow path 250 by appropriately changing the position of the water inlet 263B using the stepping motor 266. When the water inlet 263B is set at a position P1 where ice-making water is injected into the tank body 261, a circulation path R1 is formed in the ice-making water flow path 250. On the other hand, if the water inlet 263B is set at the position P2 where the ice-making water is injected into the drainage section 262, the circulation path R1 is not formed and the ice-making water can be discharged to the outside. As a result, the ice-making water can be discharged to the outside after circulating cleaning, and a switching valve for switching between circulating cleaning and drainage becomes unnecessary.

<Other embodiments>
The present invention is not limited to the embodiments described above and illustrated in the drawings; for example, the following embodiments are also included within the technical scope of the present invention.
(1) In the above embodiments, the falling type and auger type ice makers are respectively illustrated, but the types of ice makers are not limited to these. The technology described in this specification can also be applied to ice makers of other types (for example, cell type, drum type, water storage type, etc.) that include a tank and an ice making section.
(2) In the above embodiment, the distance sensor uses an ultrasonic wave, but the distance sensor is not limited to this. A distance sensor configured to measure the distance to the water surface by irradiating the water surface with a laser may be used. If the laser is difficult to reflect on the water surface, the distance to the water surface can be reduced by floating a reflective member with high light reflectivity (for example, a cylindrical float) on the water surface and irradiating the laser toward the reflective member. It may also be configured to measure.
(3) In the additional water supply process (step S4 in FIG. 5) of the first embodiment, for example, water is supplied to the tank 13 until the water level is the same as the overflow water level L1, that water level is set as the operation start water level, and a predetermined value is set from this water level. A low water level may be used as the operation stop water level. Alternatively, without executing the additional water supply process, the water level at that time may be set as the operation start water level, and a water level lower by a predetermined value from this water level may be set as the operation stop water level. Furthermore, in the additional water supply process, the control unit 80 supplies water to the tank 13 to the same level as the overflow water level L1, and then supplies water for a predetermined time, and sets the water level at that point (overflow water level) as the operation start water level, A water level lower by a predetermined value than this water level may be set as the operation stop water level.
(4) In the additional water supply process (step S4 in FIG. 5), if the water level in the tank 13 is to be supplied to the same height as the overflow water level L1, after the water level reaches the overflow water level L1 (operation start water level), ice making water is The water supply may be continued until the temperature of the ice-making unit temperature sensor 16 and the water temperature sensor 17 become lower than or equal to a predetermined temperature (for example, 5° C.). When the pump 15 is operated to cool the ice-making water, water is scattered as it flows down the ice-making surface 12A. When the water scatters, the water level in the tank 13 decreases, so ice is made from a water level lower than the operation start water level to the operation end water level, resulting in ice smaller than the desired size. By continuing to supply water until the ice-making water reaches a certain low temperature (nearly 0°C), it is possible to cool the ice-making water and replenish the amount of water splashed by the ice-making plate, thereby reducing the amount of water in the tank 13. The water level can be maintained at the overflow water level L1, which is the operation start water level, and the amount of water that has decreased from the operation start water level to the operation stop water level can be turned into ice, making it possible to more reliably produce ice of the desired size. can do.
(5) Although in the first embodiment described above, the ice-making operation is started by the user operating the operation unit 55, the ice-making operation is not limited to this. For example, when the distance to the top 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 (ice storage The ice-making operation may be started when the amount of ice in the tank 14 becomes less than a predetermined amount. That is, the control unit 80 may start the ice making operation based on the amount of ice stored in the ice storage tank 14.
(6) The control unit 80 may execute an error notification process to notify an error when the above condition FE3 or condition FE4 is satisfied for a predetermined time during the deicing operation or the cleaning operation.
(7) In the first embodiment, the predetermined temperatures C1, C2, C3, C4, C5 and the predetermined times T1, T3, T4, T5, T6, T7, T8, T9, T10 are not limited to the exemplified values. It can be set as appropriate.

DESCRIPTION OF SYMBOLS 10,210... Ice making machine, 11,220A... Ice making part, 12... Ice making board, 12A... Ice making surface, 13,260... Tank, 14,271... Ice storage tank (ice storage part), 14D, 271A... Ice storage part Top surface of ice, 15... Pump, 16... Ice making part temperature sensor, 17... Water temperature sensor, 18... Piping connecting the ice making part and pump, 19... Middle part of piping, 20... Drain pipe, 21... Drain pipe Drain valve to open and close, 22,264...Distance sensor (water level sensor), 23,275...Ice storage section side distance sensor, 33...Pump motor, 40,240...Cooling device, 58,260A...Water surface (water stored in the tank) (water surface), 80...control unit, K2...operation start distance, K4...operation stop distance, K5...first abnormal distance, K6...second abnormal distance, L1...overflow water level

Claims (6)

An ice making unit that produces ice by freezing water;
a cooling device that cools the ice making section;
a tank capable of storing water supplied to the ice making section;
a distance sensor disposed above the water stored in the tank and capable of measuring the distance to the water surface of the water stored in the tank;
a pump including a pump motor and capable of supplying water in the tank to the ice making unit as the pump motor is driven;
comprising a control unit;
The tank is configured to store unfrozen water among the water supplied to the ice making section,
The control unit includes:
An ice making operation is performed in which ice is produced in the ice making section by operating the cooling device and the pump motor,
The pump motor has a configuration capable of changing rotational speed,
The ice making unit includes an ice making plate having an ice making surface through which water flows,
The tank is arranged below the ice-making plate,
The control unit may perform a process of gradually lowering the rotational speed of the pump motor as the distance to the water surface measured by the distance sensor increases during the ice-making operation. The ice maker according to claim 1, wherein the distance sensor is configured to be able to measure the distance to the water surface by irradiating ultrasonic waves toward the water surface. The control unit includes:
When the distance to the water surface detected by the distance sensor reaches a preset driving start distance, starting the ice making operation, and
The ice making operation according to claim 1 or 2, wherein the ice making operation is stopped when the distance to the water surface detected by the distance sensor becomes an operation stop distance that is greater than the operation start distance. Machine. The tank is configured such that when the water in the tank exceeds a predetermined overflow water level, the water exceeding the overflow water level can be drained to the outside of the tank,
The ice maker according to claim 3, wherein the water level of the water surface corresponding to the operation start distance is lower than the overflow water level. The control unit is configured to control the control unit when the distance to the water surface measured by the distance sensor becomes a first abnormal distance or more, which is a value larger than the operation stop distance, or a value smaller than the operation start distance. The ice maker according to claim 3 or 4, wherein an error notification process is executed to notify an error when the distance becomes equal to or less than the second abnormal distance. an ice storage unit capable of storing ice produced in the ice making unit;
Claims 1 to 4 further comprising: an ice storage unit side distance sensor disposed above the ice stored in the ice storage unit and capable of measuring a distance to an upper surface of the ice stored in the ice storage unit. The ice maker according to any one of the above.

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