JP2017141985A - Ice maker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems that although ice grows quickly at an ice making part in a case where the ice making part is excessively cooled with an evaporator under ice making mode, in such case, there is a defect that product value as an ice is reduced by a crack due to inner stress provided to the ice and entire cloudiness and that although there are needs in the field art that ice should be created quickly since ice is not required to have excellent appearance without no crack, there is no ice maker in which former one or latter one may be selected.SOLUTION: The ice maker comprises a temperature control means setting a temperature of an ice making part 31 cooled by an evaporator 25 over a temperature at which ice R having poor appearance is generated in the ice making part 31. By virtue of a mode selection circuit 55, either of first ice making mode where ice R having excellent appearance is generated or second ice making mode where the ice R is generated quickly may be selected with using the temperature control means.SELECTED DRAWING: Figure 1

Description

  The present invention provides an ice making mode capable of selecting an ice making operation mode that gives a good appearance to ice produced in an ice making unit and an ice making operation mode that can rapidly produce ice even if the appearance may be somewhat impaired. Related to the machine.

  Ice machines that automatically manufacture ice cubes and various shapes of ice such as plates or blocks are widely used. The present invention relates to the above-mentioned ice produced by an ice making machine, for example, when it is desired to have good appearance without cracks, and when it is desired to produce ice rapidly even if the appearance is somewhat impaired. In view of market needs, an ice making machine that can satisfy this need is provided. Therefore, prior to the description of the present invention, a schematic structure of a general automatic ice making machine will be described below.

  The automatic ice making machine 10 shown in FIG. 7 closes a number of ice making chambers provided in the ice making unit 31 so as to open downward with water trays 33 from below, and ice making water is supplied from the water tray 33 to each ice making chamber from below. This is a so-called closed cell type in which a large number of ice cubes are produced by spray supply. That is, in the automatic ice making machine 10, an upper portion of a substantially box-shaped housing 11 is defined in an ice storage chamber 12, and a lower portion is defined in a machine chamber 13. An ice making mechanism 30 is disposed above the ice storage chamber 12, and the ice cubes R generated in the ice making chamber (ice making section) 31 of the ice making mechanism 30 fall by the deicing operation and enter the ice storage chamber 12. Stored. Further, the machine room 13 is provided with a compressor 21, a condenser 22, an expansion means 24, etc. constituting a refrigeration mechanism 20, which will be described later with reference to FIG. 9, and an evaporation pipe constituting a part of the refrigeration mechanism 20. 25 is closely attached to the upper surface of the ice making chamber 31.

  As shown in FIG. 8, the ice making mechanism 30 is disposed in the ice making chamber 31, which has a large number of ice making chambers 32 opened downward, the water dish 33, and the lower part of the water dish 33. The ice making water tank 34 and the water tray 33 and the water tray opening / closing mechanism 35 for tilting the ice making water tank 34 integrally are configured. A support arm 36 is attached to the left end portion (FIG. 8) of the water tray 33, and the support arm 36 is pivotally supported via a pivot shaft 38 on a bracket 37 A of an attachment member 37 installed on the casing 11. Has been. The vicinity of the right end of the water pan 33 (FIG. 8) is connected to a cam arm 39 constituting the water tray opening / closing mechanism 35 via a coil spring 40. The water tray 33 is driven to rotate the cam arm 39 forward and backward by driving the actuator motor 41, so that the ice making chamber 31 is closed by the water tray 33 and tilted downward from the ice making chamber 31. The posture is shifted to the opened state.

  The ice making water tank 34 has a bucket shape in which the left side in FIG. 8 is deeply formed, and can store ice making water supplied from a water supply unit 50 disposed above the housing 11. Yes. Further, a water supply pump 45 is disposed on the left front wall, which is the deepest part of the ice making water tank 34, and the ice making water stored in the ice making water tank 34 is passed through the injection hole 43 of the water tray 33. The ice is supplied to each ice making chamber 32 of the ice making unit 31. Further, the water supply section 50 is composed of a water supply pipe 51 connected to an external water supply source such as a water supply, and a water supply valve 52 disposed in the middle of the water supply pipe 51. The water supply valve 52 is shown in FIG. Open / close control is performed by the control circuit 53. In the present specification, the ice making water tank 34, the water supply pump 45, and the water tray 33 are collectively referred to as water supply means.

  FIG. 9 schematically shows the refrigeration mechanism (refrigeration circuit) 20 and the ice making chamber 31 and the ice storage chamber 12 shown in FIGS. 7 and 8. The refrigeration circuit 20 is configured as a refrigeration system in which a compressor 21, a condenser 22, an expansion means 24, and an evaporation pipe 25 are connected in communication by a pressure pipe body 26. A bypass pipe 29 is connected to the middle of the pipe connecting the compressor 21 and the condenser 22 and the middle of the pipe connecting the expansion means 24 and the evaporation pipe 25, and a hot gas valve 27 is connected to the bypass pipe 29. Is provided. The expansion means 24 supplies the high-pressure liquefied refrigerant condensed in the condenser 22 to the evaporation pipe 25, where it is adiabatically expanded at once to remove the heat of vaporization, thereby bringing the evaporation pipe 25 below freezing point. It is to cool down. As the expansion means 24, a small-diameter capillary tube or a valve body is used. In this specification, an expansion valve is used. In FIG. 9, reference numeral 23 denotes a fan motor that blows and cools the condenser 22.

  In the above-described closed cell type automatic ice making machine 10, ice making water is supplied to each of the ice making chambers 32 by the water supply means, and ice making operation is performed. Manufacturing. That is, the water supply valve 52 of the water supply unit 50 shown in FIG. 8 is controlled to open, and a predetermined amount of ice making water is supplied from the water supply pipe 51 to the ice making water tank 34. Next, the ice making operation is started, the freezing operation of the refrigeration circuit 20 shown in FIG. 9 is performed, and each ice making chamber 32 of the ice making chamber 31 is cooled to below the freezing point. Further, by operating the water pump 45, the ice making water stored in the ice making water tank 34 is sprayed and supplied to each of the ice making chambers 32 opened downward to generate ice cubes R in each ice making chamber 32. I will do it. The ice making water that has not been frozen in the ice making chambers 32 is collected into the ice making water tank 34 through a return hole (not shown) formed in the water tray 33, and again sent to each ice making chamber 32 by the water pump 45. Circulated. When a predetermined ice cube R is generated in each ice making chamber 32, the temperature detection sensor 28 provided in the ice making chamber 31 detects the ice making completion temperature and shifts from the ice making operation to the deicing operation. The hot gas valve 27 (FIG. 9) is switched to supply hot gas to the evaporation pipe 25 to raise the temperature of the ice making chamber 31. Further, the water tray opening / closing mechanism 35 is driven to tilt the water tray 33 to a required angle to open the ice making chamber 31, and the ice cubes R generated in each ice making chamber 32 are discharged to the ice storage chamber 12 below. Further, the ice making water remaining in the ice making water tank 34 is discharged to the drain pan 47 shown in FIGS.

  When the discharge of the ice cube R is completed, the water tray opening / closing mechanism 35 reversely operates to return the water tray 33 to the original closed position, and a predetermined amount of ice making water is supplied from the water supply unit 50 to the ice making water tank 34. Then, the ice making operation is started again, and the ice cube R is continuously generated by repeating the series of steps. When a predetermined amount of ice cube R is stored in the ice storage chamber 12, the ice storage detection switch 62 disposed in the ice storage chamber 12 detects that the ice is full, and the ice making operation is stopped. Such a method of operating an automatic ice making machine is disclosed in, for example, Patent Document 1.

JP 7-332820 A

  In the ice making operation of the automatic ice making machine, as described above, the liquefied refrigerant from the condenser 22 in the refrigeration circuit 20 is supplied to the evaporator 25 through the expansion valve 24, and in the evaporator 25. The ice making part 31 is cooled to below the freezing point by adiabatic expansion. Ice cubes R are gradually generated inside the ice making chamber 32 by supplying ice making water from the water tray 33 to each ice making chamber 32 of the ice making unit 31 cooled below the freezing point.

  Thus, the expansion valve 24 is directly related to the flow rate of the refrigerant supplied to the evaporator 25. Accordingly, when the expansion valve 24 is largely opened and a large amount of refrigerant is supplied to the evaporator 25 during the ice making operation, the ice making unit 31 is supercooled. That is, if the temperature of the ice making section 31 is continuously lowered, the ice cube R rapidly grows in the ice making chamber 32, so that stress is generated inside the ice cube R and a crack is generated. However, there is a drawback that the commercial value is lowered. The temperature of the ice making unit 31 when cracks occur in such ice cubes R varies depending on the season, the ambient temperature of the installation location, the temperature of the ice making water, etc., but is generally −20 ° C. or lower. Are known.

  Therefore, in order to manufacture ice cubes R without cracks (or as little as possible), it is known to perform opening / closing control of the expansion valve 24 so that the temperature of the ice making unit 31 does not fall below -20 ° C. . For example, as the expansion valve 24, there is an ice making machine that uses a constant pressure expansion valve (evaporation pressure control valve) that adjusts the refrigerant flow rate so that the evaporation pressure (that is, the evaporation temperature) in the evaporator 25 becomes substantially constant. However, the constant pressure expansion valve is premised on the use of the compressor 21 in the refrigeration circuit 20 rotating at a constant speed and maintaining a constant refrigerant pressure. However, depending on the power supply situation in the area where the ice making machine is used. This may affect the constant rotation of the compressor 21. In other words, since the compressor 21 has a load fluctuation in the region where the commercial power source is 50HZ and 60HZ, if the threshold value of the evaporation temperature in the evaporator 25 is set to a temperature at which the cracks occur in the ice, the compressor 21 When the load fluctuates, it may become below the temperature at which ice cracks. Further, in order to produce ice with few cracks, if the temperature of the ice making unit 31 is not lowered below −20 ° C., the ice is made slowly. There is a disadvantage that the time becomes longer.

  As described above, when ice is generated by an ice making machine, if the ice making unit is excessively cooled by an evaporator, cracks and white turbidity are generated in the obtained ice, resulting in poor appearance. In addition, there is a conflicting problem that the ice making time becomes long if an attempt is made to generate ice having a high transparency and good appearance while preventing cracks from occurring as much as possible. The present invention has been proposed to solve this problem, and the cooling temperature of the ice making part is set to a temperature (for example, −20 ° C.) at which ice having an inferior appearance (for example, generation of cracks) is generated in the ice making part. A temperature adjusting means for setting the temperature to a higher temperature, and a first mode for generating ice having a good appearance, or a second mode for rapidly generating ice even if the appearance is inferior. The above-mentioned problem is solved by selecting the mode.

In order to solve the above problems and achieve an intended object, the invention according to claim 1 is provided with a refrigeration circuit including a compressor, a condenser, an expansion means, and an evaporator, and the evaporator, An ice making unit in which refrigerant from a refrigeration circuit is supplied to the evaporator and cooled below freezing point, and water supply means for supplying ice making water to the ice making unit during ice making operation and generating ice in the ice making unit In the ice making machine, using the temperature adjusting means for setting the temperature of the ice making part cooled by the evaporator above the temperature at which ice having an inferior appearance is generated in the ice making part, and using the temperature adjusting means The gist of the invention is that it comprises a mode selection circuit for selecting either the first ice making operation mode for generating ice having a good appearance or the second ice making operation mode for rapidly generating ice.
According to the first aspect of the invention, since the cooling temperature of the ice making part cooled by the evaporator is maintained in a temperature range that does not cause cracks in the ice, ice having a good appearance is produced. Further, it is convenient to arbitrarily select the case of producing ice having a good appearance with few cracks and the case of producing ice rapidly even if the appearance is somewhat inferior.

According to a second aspect of the present invention, the temperature adjusting means is an electronic expansion valve as the expansion means in the refrigeration circuit, and is based on a detection signal from a refrigerant temperature sensor provided at least on the refrigerant inlet side of the evaporator. The gist is that the valve opening angle of the electronic expansion valve is adjusted.
According to the invention which concerns on Claim 2, the cooling temperature in an evaporator can be precisely controlled by using an electronic expansion valve as an expansion means in a refrigerant circuit.

  According to the ice making machine of the present invention, it is possible to produce ice having no cracks and excellent transparency and high commercial value, and depending on the user's wishes, the cracks are generated and the appearance is inferior. Even if there is, you can choose the mode to manufacture rapidly.

It is the schematic which shows the refrigerating circuit of the ice making machine based on the Example of this invention, and the control circuit which controls ice making operation and defrost operation. FIG. 2 is a graph showing that in the ice making machine having the circuit shown in FIG. 1, the ice making temperature moves up and down with reference to the threshold value set for the expansion valve, so that the crack does not decrease to the temperature at which ice occurs. In the refrigerating circuit shown in FIG. 1, it is a graph which shows that it does not fall to the temperature which a crack produces in ice by using a constant pressure expansion valve for an expansion valve. In the refrigerating circuit shown in FIG. 1, while using a constant pressure expansion valve, it is a graph which shows that a crack does not fall to the temperature which a crack produces in ice by rotating a fan motor also during deicing operation. In the refrigeration circuit shown in FIG. 1, the temperature type expansion valve is used, and the fan motor is alternately switched between high speed rotation and low speed rotation based on the threshold value, so that the temperature does not decrease to the temperature at which cracks occur in ice. FIG. In the refrigerating circuit shown in FIG. 1, while using an electronic expansion valve and rotating a fan motor also during deicing operation, it is a graph which shows that a crack does not fall to the temperature which arises in ice. It is a partially cutaway perspective view showing a schematic configuration of a conventionally known closed cell type automatic ice making machine. It is the schematic of the ice making mechanism in the automatic ice making machine shown in FIG. It is explanatory drawing which shows schematic structure of the freezing circuit used for the automatic ice making machine shown in FIG. 7, the ice making mechanism cooled by this freezing circuit, and the ice storage chamber arrange | positioned under this ice making mechanism.

  Next, a preferred embodiment of the ice making machine according to the present invention will be described with reference to the accompanying drawings. Since the basic structure of the ice making machine according to the embodiment is the closed cell type ice making machine described with reference to FIGS. 7 to 9, the already described members are denoted by the same reference numerals, and detailed description thereof is omitted. In addition, “inferior appearance of ice cubes” used in the present invention refers to ice that is unfavorable in appearance due to cracks in the ice cubes or cloudiness on the whole. Further, “square ice with good appearance” refers to ice having an appearance with no cracks and excellent transparency, but also includes ice with some cracks or white and low transparency. In other words, whether the appearance is inferior or the appearance of which ice is superior depends on how the user who uses the ice making machine perceives, and there is no absolute standard. Furthermore, it goes without saying that the ice making machine according to the present invention is not limited to the illustrated closed cell type ice making machine.

  The ice making machine according to the present invention, for example, in the closed cell ice making machine 10 described above, adjusts the cooling temperature of the ice making unit 31 cooled by the evaporator 25 and cracks the ice R generated in the ice making unit 31. As an example, the temperature control means 24 is set to a temperature higher than −20 ° C. at which the ice R is cracked so as not to have an inferior appearance. As the temperature adjusting means 24, as will be described later, for example, an electronic expansion valve that adjusts the flow rate of the liquefied refrigerant supplied to the evaporator 25 is used.

(Mode selection circuit)
As shown in FIG. 1, the ice making machine 10 is provided with a control circuit 53 that electrically controls the refrigeration circuit 20. The control circuit 53 controls the temperature adjusting means 24 to (1) a first ice making operation mode in which ice R having a good appearance without cracks is generated in the ice making unit 31, or (2) The ice making unit 31 is provided with a mode selection circuit 55 that can select one of the second ice making operation modes in which ice R is rapidly generated. In this second ice making operation mode, the ice R is rapidly produced as necessary, so that the ice R obtained in the ice making part 31 may be cracked or totally clouded by overcooling. There is.

  Further, the control circuit 53 is provided with threshold setting means 56 (described later) for setting a cooling temperature threshold in the temperature adjusting means 24. The control circuit 53 is electrically controlled by a compressor 21, a fan motor 23, an electronic expansion valve 24, a hot gas valve 27, and an actuator motor in the ice making mechanism 30 in the refrigeration circuit 20, as shown in FIG. 41, a water supply pump 45, a water supply valve 52, and the like.

(About temperature control means)
As described above, when the ice making unit 31 is excessively cooled by the evaporator 25 and, for example, the ice making unit 31 is cooled to −20 ° C. or less, the ice R grows rapidly, and the generation process As a result, the internal stress of the ice R is increased to cause cracks, or the entire surface of the ice R becomes cloudy, thereby deteriorating the appearance of the ice R. Therefore, by appropriately controlling the flow rate of the refrigerant supplied to the evaporator 25, the cooling temperature of the ice making unit 31 cooled by the evaporator 25 is set to be higher than −20 ° C., for example. Thus, it is possible to stably manufacture the ice R having a good appearance without cracks.

  As the temperature adjusting means, for example, an electronic expansion valve 24 shown in FIG. 1 is preferably employed. The electronic expansion valve 24 is an expansion valve that is interposed in a conduit system between the condenser 22 and the evaporator 25 in the refrigeration circuit 20. It is controlled by the temperature difference detected by the temperature sensor S1 provided on the inlet side and the temperature sensor S2 provided on the outlet side of the evaporator 25. That is, the valve body of the electronic expansion valve 24 can continuously and variably control the degree of opening and closing by an actuator (not shown) such as a pulse motor. Then, the temperature sensors S1 and S2 detect the temperatures on the inlet side and the outlet side of the evaporator 25, respectively, and the control circuit 53 performs signal processing on the temperature difference to give a control command to the pulse motor. The opening degree of the valve body in the electronic expansion valve 24 is adjusted. Thereby, the liquefied refrigerant from the refrigeration circuit 20 is supplied to the evaporator 25 at an optimum flow rate, and the cooling temperature of the evaporator 25 can be set precisely. Specifically, when the temperatures detected by the two temperature sensors S1 and S2 are compared with each other, if the temperature difference is large, the degree of opening of the electronic expansion valve 24 is increased to flow into the evaporator 25. Increase the flow rate of refrigerant. Conversely, when the temperature difference is small, control is performed to reduce the refrigerant flow rate to the evaporator 25 by reducing the degree of valve opening. Note that it is not a requirement to use both of the temperature sensors S1 and S2. For example, the temperature sensors S1 and S2 may be provided only on the inlet side of the evaporator 25.

  By using the electronic expansion valve 24 in this way, the refrigerant flow rate in the evaporator 25 can be adjusted. However, the ice making unit 31 can generate the ice R having a good appearance without cracks. Therefore, it is necessary to prevent the evaporation temperature in the evaporator 25 from being lower than the aforementioned −20 ° C. Therefore, a threshold value for controlling the opening and closing of the electronic expansion valve 24 (temperature difference between the inlet side and the outlet side of the evaporator 25) is set to −20 ° C. or more by the threshold value setting means 56 shown in FIG. When the evaporator 25 is excessively cooled during the ice making operation and falls below a preset threshold value of the electronic expansion valve 24, the degree of opening of the electronic expansion valve 24 is reduced to reduce the evaporator 25. The evaporation temperature is raised by reducing the amount of refrigerant flowing into the. After the transition in this state, when the temperature of the evaporator 25 exceeds the set temperature of the threshold value, the opening degree of the valve body in the electronic expansion valve 24 is increased again to increase the refrigerant inflow amount. This cycle is repeated thereafter.

  The repeated cycle is shown in the graph of FIG. The vertical axis in FIG. 2 indicates the ice making temperature (° C.), and the horizontal axis indicates the ice making time (t). The temperature serving as the threshold is set in a range that is above the temperature at which the above-described ice cracks is −20 ° C. and below 0 ° C. When the ice making operation is started, the ice making temperature of the evaporator 25 (that is, the ice making unit 31) rapidly decreases. However, when the temperature falls below the threshold set in the electronic expansion valve 24, the valve body in the electronic expansion valve 24 is used. Therefore, the temperature of the evaporator 25 is reversed and rises. That is, since the temperature does not decrease to the temperature of −20 ° C., no cracks are generated in the ice R generated in the ice making unit 31, and a transparent and good appearance is obtained. Thus, the temperature of the ice making unit 31 does not fall below -20 ° C., and the cycle of raising and lowering the threshold temperature is repeated during the ice making operation. When the deicing operation is switched, the hot gas valve 27 is opened and high-temperature vaporized refrigerant is supplied to the evaporator 25, so that the evaporator 25 rapidly rises in temperature and heats the ice making unit 31. Then, the ice R having a good appearance without cracks is discharged from the ice making unit 31.

  The above description is a case where transparent ice that does not cause cracks is generated in the ice making unit 31, and is referred to as a first ice making operation mode in the present specification in relation to the following description. In the first ice making operation mode, the ice making time is also relatively slowly performed in order to keep the ice making temperature within a range that rises and falls based on the threshold value. For this reason, the ice R produced | generated does not become cloudy, and the thing with high transparency is obtained, and this also raises the commercial value of ice.

  However, depending on the site where ice is required, there is a case where it is desired to manufacture rapidly and in large quantities even ice that is cracked or clouded and whose appearance has deteriorated. In this case, the ice making section is set until the ice making operation is completed by setting the threshold value set for the electronic expansion valve 24 to a temperature of −20 ° C. or less by the threshold value setting means 56 (for example, dial operation is possible) shown in FIG. 31 is subcooled. At this time, the ice produced in the ice making section 31 is cracked or clouded and looks inferior, but has the advantage that the ice can be produced rapidly. As described above, the mode in which ice is rapidly generated in a short time is referred to as a second ice making operation mode in this specification. In the second ice making operation mode, the threshold value itself is not limited to the case where the threshold value setting unit 56 sets the threshold value of the electronic expansion valve 24 to −20 ° C. or less, and the threshold value itself may be invalidated. That is, by invalidating the threshold value, the electronic expansion valve 24 is not controlled during the ice making operation, so that the supercooling of the evaporator 25 (and the ice making unit 31) proceeds. The first ice making operation mode or the second ice making operation mode can be selected according to the user's preference by operating the mode selection circuit 55 shown in FIG. For example, the ice used for cocktails is selected from the first ice making operation mode because it is preferred to use transparent ice without cracks. In addition, when the ice is rapidly required to cool the food or when the split ice is required, the second ice making operation mode may be selected because the crack may be generated or clouded. .

  In the refrigeration circuit 20 of FIG. 1, the constant pressure expansion valve described above may be used as the expansion valve. Of course, in this case, the temperature sensors S1 and S2 are not used. In the constant pressure expansion valve, when the pressure of the liquefied refrigerant supplied from the condenser 22 to the constant pressure expansion valve in the refrigeration circuit 20 is constant, the degree of opening of the valve body is also kept constant. The temperature of the ice making unit 31) can be kept constant regardless of the ambient temperature. Therefore, if the degree of opening of the valve body in the constant pressure expansion valve is set to a temperature higher than −20 ° C., good ice without cracking is generated. The behavior of the ice making temperature in this case is shown in the graph of FIG.

  FIG. 4 shows another embodiment when the constant pressure expansion valve shown in FIG. 3 is used, and shows a case where the rotation of the fan motor 23 is continued during the deicing operation. That is, in FIG. 4, the rotation of the fan motor 23 is continued not only during the ice making operation but also after switching to the deicing operation. Accordingly, the condenser 22 is continuously cooled by the fan motor 23, so that the evaporation temperature of the refrigerant supplied from the hot gas valve 27 can be made as low as possible during the deicing operation. Accordingly, it is possible to reduce cracks that are likely to occur when the ice R is peeled off from the ice making unit 31 by the deicing operation.

  FIG. 5 shows an embodiment of an ice making machine using a temperature type expansion valve. That is, during the ice making operation, the vaporized refrigerant that has passed through the condenser 22 and exchanged heat is at a high temperature. Therefore, the condenser 22 that cools the vaporized refrigerant and uses it as a liquefied refrigerant has a high speed of the fan motor 23. Cooled by rotation. The fan motor 23 is set with a control threshold value for separating the case of rotating at a high speed and the case of rotating at a low speed. For example, the temperature detection sensor (ice-making thermistor) 28 shown in FIG. 8 constantly monitors the temperature of the ice-making unit 31, but the temperature detected by the temperature detection sensor 28 of −20 ° C. is set in the fan motor 23. It is set as the threshold value for the control. In FIG. 5, when the temperature detection sensor 28 detects that the temperature has decreased beyond the threshold value −20 ° C. set for the fan motor 23, the fan motor 23 switches its rotational speed to the low speed side. Thereby, the evaporation temperature of the refrigerant in the evaporator 25 rises. Thereafter, when the temperature detection sensor 28 detects that the temperature has exceeded the threshold of −20 ° C., the rotation speed of the fan motor 23 is switched to the high speed side, and the evaporation temperature of the refrigerant in the evaporator 25 is increased.

  Thus, by controlling the switching of the high speed rotation and the low speed rotation of the fan motor 23 based on the threshold value until the ice making in the ice making part 31 is completed, the ice making temperature of the ice making part 31 is a temperature at which the ice is cracked. Is not exceeded. That is, it is possible to produce transparent and good-looking ice with few cracks.

  FIG. 6 shows an embodiment of an ice making machine using an electronic expansion valve, and the control mode of the electronic expansion valve is basically the same as described above with reference to FIG. However, in this case, as shown in FIG. 6, the condenser 22 is further cooled by continuing the rotation of the fan motor 23 not only during the ice making operation but also during the deicing operation. Thereby, condensation of the refrigerant in the condenser 22 is promoted, and the hot gas valve 27 can be opened during the deicing operation to reduce the refrigerant used. Further, since the flow rate of the refrigerant can be controlled by controlling the electronic expansion valve 24 even during the deicing operation, the temperature of the hot gas from the hot gas valve 27 can be made lower than usual. Thereby, since the expansion | swelling of the ice at the time of deicing operation can be suppressed, transparent ice with few cracks is manufactured.

20 refrigeration mechanism (refrigeration circuit), 21 compressor, 22 condenser,
24 expansion valve (expansion means), temperature control means, 25 evaporation pipe (evaporator),
31 ice making chamber (ice making section), 33 water supply means (water tray), 34 water supply means (ice making water tank),
45 Water supply means (water pump), 55 mode selection circuit, R ice cube (ice),
S1 Refrigerant temperature sensor

Claims (3)

A refrigeration circuit (20) composed of a compressor (21), a condenser (22), expansion means (24), and an evaporator (25), and the evaporator (25) are arranged from the refrigeration circuit (20). Is supplied to the evaporator (25) and cooled to below freezing point, and ice making water is supplied to the ice making unit (31) during the ice making operation to the ice making unit (31). In an ice making machine comprising water supply means (34, 45, 33) for generating ice (R),
Temperature adjusting means for setting the temperature of the ice making unit (31) cooled by the evaporator (25) above the temperature at which ice (R) having an inferior appearance is generated in the ice making unit (31);
A mode selection circuit for selecting either the first ice making operation mode for generating ice (R) having a good appearance or the second ice making operation mode for rapidly generating ice (R) using the temperature adjusting means ( 55) and an ice making machine.   The temperature adjusting means is an electronic expansion valve (24) as the expansion means in the refrigeration circuit (20), and is supplied from a refrigerant temperature sensor (S1) provided at least on the refrigerant inlet side of the evaporator (25). The ice making machine according to claim 1, wherein a valve opening angle of the electronic expansion valve (24) is adjusted by a detection signal.   The first ice making operation mode is a control mode in which cracks are hardly generated in the ice (R) generated in the ice making section (31), and the second ice making operation mode is a method of rapidly producing ice (R). The ice making machine according to claim 1 or 2, wherein generation is a control mode in which priority is given to the possibility of cracks in the ice.

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