JP5962054B2 - Auger ice machine and cooling system - Google Patents

Description

  The present invention relates to an auger type ice making machine and a cooling device, and more particularly to an auger type ice making machine and an cooling device provided with an electronic expansion valve.

  2. Description of the Related Art Conventionally, an auger type ice making machine including an electronic expansion valve is known (for example, see Patent Document 1). Such an auger type ice making machine is mounted on, for example, a cup type vending machine that sells a cold beverage prepared by putting ice into a mixed solution of syrup and dilution water.

  In Patent Document 1, an ice making cylinder having an auger (spiral rotating blade) disposed therein and at least a compressor, a condenser, an electronic expansion valve, and an evaporator, and cooling for cooling the ice making cylinder. An auger type ice making machine including a unit (refrigeration cycle apparatus) is disclosed. In the auger type ice making machine described in Patent Document 1, the evaporation pipe constituting the evaporator is spirally wound along the outer periphery of the ice making cylinder, and the refrigerant adjusted to a predetermined flow rate by the electronic expansion valve evaporates. The ice making cylinder is cooled by being distributed in the pipe. At this time, in Patent Document 1, based on the outlet temperature of the evaporation pipe (refrigerant temperature at the outlet), a desired degree of superheat is obtained (so that the outlet temperature of the evaporation pipe becomes a desired temperature). It is comprised so that the opening degree of an expansion valve may be controlled.

Japanese Patent Laid-Open No. 9-4950

  Here, in the auger type ice making machine having the conventional electronic expansion valve as described in Patent Document 1, the ice making operation is performed when the opening degree of the electronic expansion valve is controlled so as to obtain a desired degree of superheat. After the start, the opening degree of the electronic expansion valve is largely changed from the fully opened state to a predetermined initial opening degree, and then the evaporation pipe temperature (outlet temperature) becomes a desired target temperature (a predetermined superheat degree is obtained). It is known to perform control to finely adjust the opening from the initial opening.

  However, since the electronic expansion valve has a valve body (orifice) that is mechanically opened and closed, there are individual differences (variations) between products due to processing errors and assembly errors of the valve body. In addition, there is an inconvenience that the refrigerant circulation amount varies due to variations in the electronic expansion valve. Due to variations in the components of the cooling system such as the electronic expansion valve and the refrigerant flow rate, the predetermined evaporator temperature (target temperature) may not be reached unless the opening is significantly changed from the initial opening. is there. In this case, if control is performed to finely adjust the opening from the initial opening as before, it takes time from the start of ice making operation to the target evaporator temperature, and as a result, the state of ice during ice making There is a problem that it takes time to stabilize (ice quality). In particular, in a cup-type vending machine, if the soft soft ice condition lasts for a long time before the ice condition stabilizes, the quality of the ice that is put into the beverage to be sold after the ice pieces freeze (freeze). It is desirable to stabilize the quality of ice quickly because it may decrease.

  The present invention has been made to solve the above problems, and one object of the present invention is to reach the target evaporator temperature even when the components of the cooling system vary. An auger type ice making machine and a cooling device capable of quickly stabilizing the ice condition by shortening the time required for the above are provided.

Auger type ice making machine according to a first aspect of the invention, the ice making evaporator auger is disposed on the outer periphery of the ice making cylinder disposed therein, a refrigerant temperature detecting unit for detecting the refrigerant temperature of the ice making evaporator ambient An ambient temperature detector that detects the temperature, an electronic expansion valve that controls the amount of refrigerant flowing into the ice making evaporator according to the opening, and a controller that controls the opening of the electronic expansion valve, after changing the opening degree of the electronic expansion valve and determines the first opening of the initial opening of the electronic expansion valve based on the ambient temperature detected by the ambient temperature detecting section to the first opening, at least the refrigerant The opening degree of the electronic expansion valve is changed from the first opening degree to the second opening degree based on the refrigerant temperature of the ice making evaporator detected by the temperature detecting unit, and then the refrigerant temperature of the ice making evaporator reaches a predetermined target temperature. Is configured to control the opening of the electronic expansion valve That.

In the auger type ice making machine according to the first aspect of the present invention, as described above, after changing the opening of the electronic expansion valve to the first opening as the initial opening, the ice making detected at least by the refrigerant temperature detecting unit. The opening of the electronic expansion valve is changed from the first opening to the second opening based on the refrigerant temperature of the evaporator, and then the electronic expansion valve is opened so that the refrigerant temperature of the ice making evaporator becomes a predetermined target temperature. By controlling the degree, the opening degree of the electronic expansion valve is adjusted so that the refrigerant temperature of the ice making evaporator becomes a predetermined target temperature after the change to the first opening degree (initial opening degree) (change control of only one stage). Unlike the case of controlling (finely), the two-stage change control of the first opening and the second opening can be performed before finely controlling the opening of the electronic expansion valve. That is, after changing to the first opening as the initial opening, further, based on the detected refrigerant temperature of the ice making evaporator, a cooling characteristic (cooling performance) that varies due to variations in the components of the cooling system is determined, After performing the two-stage change control of determining and changing the second opening according to the determined cooling characteristics, it is possible to reach the target evaporator temperature earlier by finely controlling the opening. . Thereby, even when there are variations in the components of the cooling system, the time required to reach the target evaporator temperature can be shortened and the ice state (ice quality) can be stabilized quickly. As a result, the ice quality can be further stabilized.
In addition, an ambient temperature detection unit that detects ambient temperature is provided, and the control unit is configured to determine a first opening as an initial opening of the electronic expansion valve based on the ambient temperature detected by the ambient temperature detection unit. Has been.

  In addition, if the auger type ice making machine according to the first aspect of the present invention described above is mounted on a cup type vending machine, the ice state (ice quality) can be quickly stabilized to prevent the soft ice state from prolonging. Therefore, it is possible to effectively prevent the quality of ice to be put into beverages to be sold due to freezing (freezing) between ice pieces of soft ice.

In the auger type ice making machine according to the first aspect, preferably, the ambient temperature detection unit is configured to detect the ambient temperature of the auger type ice making machine, and the control unit is detected by the refrigerant temperature detection unit. Based on the refrigerant temperature of the ice making evaporator and the ambient temperature of the auger type ice making machine detected by the ambient temperature detector, control is performed to change the opening of the electronic expansion valve from the first opening to the second opening. It is configured as follows. With this configuration, the cooling characteristic of the cooling system can be determined in consideration of not only the detected refrigerant temperature of the ice making evaporator but also the ambient temperature of the auger type ice making machine. Can be determined more appropriately and change control can be performed. Here, the ambient temperature of an auger type ice maker is not only the ambient temperature of an auger type ice maker alone, but also the ambient temperature (outside air temperature) of a cup type vending machine incorporating an auger type ice maker. It is a broad concept including.

  In the auger type ice making machine according to the first aspect, preferably, the control unit sets the opening degree of the electronic expansion valve based on the refrigerant temperature of the ice making evaporator after a predetermined time has elapsed after changing to the first opening degree. The first opening is changed to the second opening. If comprised in this way, a cooling characteristic (cooling performance) will be judged based on the refrigerant | coolant temperature obtained as a result of continuing driving | running for the predetermined time in the state which the opening degree of an electronic expansion valve is a 1st opening degree, and 2nd Since the opening is changed, the cooling characteristic can be determined more accurately, unlike the case where the cooling characteristic is determined immediately after the change to the first opening. Thereby, change control can be performed by more accurately determining the second opening.

  In the auger type ice making machine according to the first aspect, preferably, when the control unit changes to the second opening, the control unit performs the first operation with respect to the refrigerant within the first temperature range with respect to the predetermined target temperature. When the opening degree is controlled from the opening degree to the second opening degree and the opening degree of the electronic expansion valve is controlled after the change to the second opening degree, it is smaller than the first temperature range with respect to a predetermined target temperature. With respect to the refrigerant in the second temperature range, the opening degree of the electronic expansion valve is controlled so as to reach a predetermined target temperature. As described above, the temperature range of the refrigerant (first temperature range) when changing the electronic expansion valve from the first opening to the second opening is changed to the opening degree control after the change to the second opening. If the temperature is set to be larger than the temperature range of the refrigerant (second temperature range), the refrigerant temperature of the ice making evaporator can be changed in a larger range by changing from the first opening to the second opening. Therefore, the target evaporator temperature can be reached earlier.

  In the auger type ice making machine according to the first aspect, preferably, the refrigerant temperature detection unit is configured to detect the refrigerant temperature on the outlet side of the ice making evaporator, and the control unit is detected by the refrigerant temperature detection unit. Based on the refrigerant temperature at the outlet side of the ice making evaporator, control is performed to change the opening of the electronic expansion valve from the first opening to the second opening. If constituted in this way, specifications of the cooling system constituting the auger type ice making machine (for example, specifications of the compressor and ice making evaporator (heat exchanger), specifications of the electronic expansion valve (flow rate characteristics of the valve body)), refrigerant Considering the refrigerant temperature on the inlet side of the ice making evaporator, which can be grasped in advance from the specifications of the piping and the amount of refrigerant charged, etc., the refrigerant after circulating the ice making evaporator based on the detected refrigerant temperature on the outlet side of the ice making evaporator Therefore, it is possible to easily determine the cooling characteristics that vary due to variations in the components of the cooling system based on the determined degree of superheat. Thereby, change control from the first opening to the second opening can be easily performed. Further, if the refrigerant temperature only on the outlet side of the ice making evaporator is detected, the refrigerant temperature detection unit (temperature sensor) for detecting the refrigerant temperature can be made one, so that the apparatus configuration is simplified. Can do.

  In the auger type ice making machine according to the first aspect, preferably, the control unit performs electronic expansion based on the fact that the refrigerant temperature of the ice making evaporator detected by the refrigerant temperature detecting unit has become the first opening change temperature. Control is performed to change the opening of the valve to the first opening as the initial opening. Here, when the ice making operation is started in a state where the apparatus is cooled, the refrigerant temperature immediately decreases to a low temperature. In this case, if control is performed to uniformly change the opening of the electronic expansion valve to the first opening (initial opening) after a certain fixed time from the start of the ice making operation, the first opening (before the first opening) The liquid-rich refrigerant having a small dryness (containing a relatively large amount of liquid phase) flows too much (before the change to). Therefore, in the present invention, by controlling to change to the first opening degree based on the fact that the refrigerant temperature has reached the first opening degree changing temperature (decreasing to the first opening degree changing temperature), Even when the ice making operation is started in a state where the apparatus is cooled, the refrigerant temperature is changed to the first opening when the refrigerant temperature is lowered to the first opening changing temperature, so before the change to the first opening, It is possible to prevent the liquid-rich refrigerant having a small dryness from flowing too much. Further, by setting the change of the refrigerant temperature to the first opening degree change temperature as a starting point (trigger) for changing to the first opening degree, the refrigerant temperature is set immediately after the ice making operation is started with the apparatus cooled. When the temperature drops to the first opening change temperature, the first opening can be changed at an early stage without waiting for the elapse of a fixed time, so that the target evaporator temperature can be reached earlier.

In this case, preferably, the ambient temperature detection unit is configured to detect the ambient temperature of the auger type ice making machine, and the control unit includes the auger detected by the ambient temperature detection unit in addition to the first opening degree. based on the ambient temperature of the formula icemaker it is configured to determine a first opening degree variation temperature to change to the first opening. If comprised in this way, even when the situation of the refrigerating cycle accompanying ice making operation differs with the ambient temperature of an auger type ice making machine, the optimal first opening (initial opening) of the electronic expansion valve according to the ambient temperature and The first opening change temperature to be changed to the first opening can be determined.

In the auger type ice making machine according to the first aspect, preferably, the ambient temperature detection unit is configured to detect the ambient temperature of the auger type ice making machine, and the control unit is detected by the ambient temperature detection unit. A predetermined target temperature is determined based on the ambient temperature of the auger type ice making machine. According to this configuration, even when the refrigeration cycle state associated with the ice making operation differs depending on the ambient temperature of the auger type ice making machine, the optimum target temperature for the refrigerant temperature of the ice making evaporator is determined according to the ambient temperature Can do.

  In the auger type ice making machine according to the first aspect, preferably, the refrigerant is carbon dioxide. If comprised in this way, unlike an chlorofluorocarbon type refrigerant | coolant, an auger type ice maker using the carbon dioxide refrigerant which does not destroy an ozone layer and has little influence with respect to the global environment as a low temperature chamber effect gas can be provided.

A cooling device according to a second aspect of the present invention includes a refrigerant temperature detection unit that detects a refrigerant temperature of an evaporator, an ambient temperature detection unit that detects an ambient temperature, and an amount of refrigerant that flows into the evaporator according to an opening degree. an electronic expansion valve for controlling, and a control unit for controlling the opening of the electronic expansion valve, the control unit, as initial opening of the electronic expansion valve based on the ambient temperature detected by the ambient temperature detecting unit After determining the first opening and changing the opening of the electronic expansion valve to the first opening , the first opening of the electronic expansion valve is set based on at least the refrigerant temperature of the evaporator detected by the refrigerant temperature detector. The opening degree is changed from the opening degree to the second opening degree, and then the opening degree of the electronic expansion valve is controlled so that the refrigerant temperature of the evaporator becomes a predetermined target temperature.

In the cooling device according to the second aspect of the present invention, as described above, after changing the opening of the electronic expansion valve to the first opening as the initial opening, at least the evaporator temperature detected by the refrigerant temperature detection unit The opening degree of the electronic expansion valve is changed from the first opening degree to the second opening degree based on the refrigerant temperature, and then the opening degree of the electronic expansion valve is controlled so that the refrigerant temperature of the evaporator becomes a predetermined target temperature. As a result, the opening degree of the electronic expansion valve is (finely) controlled so that the refrigerant temperature of the evaporator becomes a predetermined target temperature after changing to the first opening degree (initial opening degree) (change control of only one stage). Unlike the case where it does, before carrying out fine control of the opening degree of an electronic expansion valve, the change control of 2 steps | paragraphs of a 1st opening degree and a 2nd opening degree can be performed. That is, after changing to the first opening as the initial opening, further, based on the detected refrigerant temperature of the evaporator, a cooling characteristic (cooling performance) that varies due to variations in the components of the cooling system is determined, After performing the two-stage change control of determining and changing the second opening according to the determined cooling characteristics, the opening can be finely controlled, so that the target evaporator temperature can be reached earlier. As a result, even when there are variations in the components of the cooling system, the time required to reach the target evaporator temperature can be shortened, and the object to be cooled can be quickly cooled. As a result, the quality of the cooling object can be further stabilized.
In addition, an ambient temperature detection unit that detects ambient temperature is provided, and the control unit is configured to determine a first opening as an initial opening of the electronic expansion valve based on the ambient temperature detected by the ambient temperature detection unit. Has been.

  According to the present invention, as described above, even when there are variations in the components of the cooling system, the time required to reach the target evaporator temperature can be shortened to quickly stabilize the ice state. .

It is the figure which showed the schematic whole structure of the auger type ice making machine by one Embodiment of this invention. It is the figure which showed the detail of the structure around the ice making unit of the auger type ice making machine by one Embodiment of this invention. It is the control block diagram which showed the structure of the auger type ice making machine by one Embodiment of this invention. It is a mimetic diagram for explaining opening control of an electronic expansion valve at the time of cycle operation at the time of ice making by an auger type ice making machine by one embodiment of the present invention. It is the figure which showed the 1st opening degree table for determining the 1st opening degree (initial opening degree) of the electronic expansion valve in the cooling unit of the auger type ice making machine by one Embodiment of this invention. It is the figure which showed the 2nd opening degree table for determining the 2nd opening degree of the electronic expansion valve in the cooling unit of the auger type ice making machine by one Embodiment of this invention. It is a mimetic diagram for explaining opening control of an electronic expansion valve at the time of pull-down operation at the time of ice making performed by an auger type ice making machine by one embodiment of the present invention. It is the figure which showed the opening degree control processing flow of the control part at the time of the ice making operation | movement (at the time of a cycle operation and the pull-down operation) of the auger type ice making machine by one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, with reference to FIGS. 1-6, the structure of the auger type ice making machine 100 by one Embodiment of this invention is demonstrated. The auger type ice making machine 100 is an example of the “cooling device” in the present invention. The auger type ice making machine 100 according to the present embodiment is mounted on, for example, a cup type vending machine that sells a cold beverage prepared by putting ice into a mixed solution of syrup and dilution water.

As shown in FIG. 1, the auger type ice making machine 100 according to the present embodiment can perform ice making by an auger type with a cooling unit 70 capable of forming a predetermined refrigeration cycle using a carbon dioxide refrigerant (CO ₂ ). The ice making unit 80 is provided.

  The cooling unit 70 includes at least the compressor 10, the gas cooler (heat radiator) 20, the internal heat exchanger 30, the electronic expansion valve 40, the ice making evaporator 50, and refrigerant pipes 5a to 5d that connect these functional components. Yes. The refrigerant discharged from the compressor 10 flows along the direction of the arrow P in the order of the gas cooler 20, the internal heat exchanger 30, the electronic expansion valve 40, the ice making evaporator 50, and the internal heat exchanger 30, and again the compressor 10 The cycle of returning to is repeated. Further, the auger type ice making machine 100 includes a control unit 60 for controlling the operation of the cooling unit 70 and the ice making unit 80 in the apparatus main body. The ice making unit 80 incorporates the ice making evaporator 50 of the cooling unit 70. The ice making evaporator 50 is an example of the “evaporator” and “ice making evaporator” of the present invention.

  As shown in FIG. 2, the ice making unit 80 includes a stainless steel ice making cylinder 81. A single evaporating pipe 51 constituting the ice making evaporator 50 is wound spirally along the outer periphery of the ice making cylinder 81 with a gap in the axial direction (Z direction). In addition, an auger 82 provided with a spiral cutting blade 82 a is rotatably disposed inside the ice making cylinder 81. A fixed blade 83 is provided on the ice making cylinder 81, and an ice storage chamber 84 is connected to the fixed blade 83. In addition, an ice making water tank 85 for supplying ice making water to the ice making cylinder 81 is connected to a side surface near the bottom of the ice making cylinder 81 through a water supply pipe 85a. An auger motor 86 for rotating the auger 82 in a predetermined direction is installed below the auger 82.

  Further, as shown in FIG. 2, the ice storage chamber 84 has a cylindrical heat insulating wall 84a that constitutes a side wall portion and a bottom portion, and an ice piece payout portion is provided at a predetermined position on the side wall portion of the ice storage chamber 84. A discharge door (not shown) is provided. In the ice storage chamber 84, there are a rotation shaft 87 connected to the rotation shaft of the auger 82, a plurality of stirring rods (agitators) 88 protruding radially downward from the rotation shaft 87, and the bottom of the ice storage chamber 84 ( And an ice stacking unit 89 for stacking ice pieces. During the ice making operation, the stirring rod 88 that rotates in conjunction with the auger 82 stirs the ice pieces in the ice storage chamber 84, thereby preventing the ice pieces in the ice storage chamber 84 from freezing and forming large ice blocks. Is done.

  As shown in FIG. 2, a detection plate 90 a that is movable in the vertical direction while being supported by the rod 90 b is disposed in the upper portion (in the vicinity of the ceiling portion 84 b) in the ice storage chamber 84. Further, an ice storage amount detection switch 91 for detecting that the detection plate 90 a has been moved to a predetermined upper position is disposed on the upper surface of the ice storage chamber 84. The ice storage amount detection switch 91 is electrically connected to the control unit 60 (see FIG. 3) in the apparatus main body, and the ice storage amount in the ice storage chamber 84 is equal to or less than a predetermined amount, and the detection plate 90a is at a predetermined position above. If not reached, for example, it is turned on, and if the amount of stored ice is increased by the ice making operation and the detection plate 90a is moved to a predetermined upper position, it is turned off, for example.

  As an operation of the auger type ice making machine 100 (see FIG. 1) having the above configuration, first, the cooling unit 70 (see FIG. 1) is operated to cool the ice making evaporator 50 to a temperature lower than the freezing point. Thus, thin ice is formed on the inner wall surface of the ice making cylinder 81 using the ice making water supplied from the ice making water tank 85. Then, the cutting blade 82a of the auger 82 rotated by the auger motor 86 along with the formation of thin ice continuously feeds the thin ice upward (Z1 direction). Then, the flake-shaped thin ice scraped off is pressed and hardened by the fixed blade 83 to form ice pieces, which are sequentially pushed into the ice storage chamber 84.

  Further, the auger type ice making machine 100 is configured such that the ice making operation state and the ice making operation stop state (standby state) are repeated based on the ON state and the OFF state of the ice storage amount detection switch 91. Depending on the amount of ice dispensed from the ice storage chamber 84, when the operation load (operation rate) is low, as an example, ice making operation is performed for about 5 minutes to 10 minutes in one hour, and the amount of ice shortage The cycle operation is performed so that the ice making operation is stopped (standby state) for the remaining time (about 50 to 55 minutes). Therefore, it is required to form thin ice in the ice making cylinder 81 in a shorter time from the start of the ice making operation.

  As shown in FIGS. 1 and 2, an ambient temperature sensor 71 is provided in the vicinity of the ice making evaporator 50 in the ice making unit 80. The ambient temperature sensor 71 is connected to the control unit 60 (see FIG. 1) in the apparatus main body, and has a function of detecting the ambient temperature Ta in the vicinity of the ice making evaporator 50. The ambient temperature sensor 71 is an example of the “ambient temperature detector” in the present invention.

  Moreover, as shown in FIG. 1, the compressor 10 which comprises the cooling unit 70 has a role which compresses the refrigerant | coolant suck | inhaled from the low voltage | pressure side in a refrigerating cycle, and discharges it to a high voltage | pressure side. The gas cooler (heat radiator) 20 has a function of performing heat exchange between the refrigerant in the superheated gas state and the external air when the high-temperature and high-pressure refrigerant discharged from the compressor 10 is circulated. Moreover, the cooling unit 70 includes a blower 21 that blows air to the gas cooler 20, and the gas refrigerant in the gas cooler 20 is cooled by air blown by the blower 21. The internal heat exchanger 30 is between the refrigerant cooled by the gas cooler 20 to a temperature close to the ambient temperature Ta (air temperature) in the apparatus main body and the low-temperature and low-pressure refrigerant returned from the ice making evaporator 50 to the compressor 10. It has a function to perform heat exchange.

  The electronic expansion valve 40 has a role of expanding and reducing (reducing pressure) the refrigerant cooled by the internal heat exchanger 30 and supplying it to the ice making evaporator 50. Here, the electronic expansion valve 40 is configured to open and close the valve mechanism using the driving force of the stepping motor 40a driven by pulse control.

  The refrigerant expanded by the electronic expansion valve 40 flows into the ice making evaporator 50 (evaporation pipe 51) through the refrigerant pipe 5c while maintaining a two-phase state composed of a gas phase and a liquid phase. The ice making evaporator 50 has a function of evaporating the two-phase refrigerant supplied from the electronic expansion valve 40 in the evaporation pipe 51. At this time, the refrigerant evaporates while obtaining a predetermined latent heat of vaporization from the inlet 51a toward the outlet 51b. Since the amount of heat of the ice making water supplied to the inner wall portion of the ice making cylinder 81 during the process of evaporating the refrigerant is lost, the ice making water is cooled and thin ice is formed on the inner wall portion of the ice making cylinder 81. As shown in FIG. 1, the refrigerant after evaporating in the evaporation pipe 51 exits the outlet 51b and flows through the refrigerant pipe 5d and receives a predetermined amount of heat from the high-pressure side refrigerant in the internal heat exchanger 30. Returned to the compressor 10.

  Here, in the present embodiment, one refrigerant temperature sensor 72 is attached to the refrigerant pipe 5d near the outlet 51b of the ice making evaporator 50. The refrigerant temperature sensor 72 is connected to the control unit 60 in the apparatus main body, and has a function of detecting the refrigerant temperature (exit refrigerant temperature) Te on the outlet side of the ice making evaporator 50. The stepping motor 40a is pulse-controlled based on the outlet refrigerant temperature Te of the ice making evaporator 50 detected by the refrigerant temperature sensor 72, and the opening of the electronic expansion valve 40 is adjusted, whereby the outlet 51b of the evaporation pipe 51 is adjusted. The refrigerant is configured to obtain a predetermined degree of superheat. The refrigerant temperature sensor 72 is an example of the “refrigerant temperature detection unit” of the present invention, and the outlet refrigerant temperature Te is an example of the “refrigerant temperature of the ice making evaporator” and the “refrigerant temperature of the evaporator” of the present invention. is there. In the auger type ice making machine 100 according to the present embodiment, the specifications of the cooling system (the specifications of the compressor 10, the specifications of the ice making evaporator 50 (evaporation pipe 51), the specifications of the electronic expansion valve 40 (the flow characteristics of the valve body). In consideration of the refrigerant temperature in the vicinity of the inlet 51a of the ice making evaporator 50 that can be grasped in advance based on the specifications of the refrigerant pipes 5a to 5d and the amount of refrigerant enclosed in the cooling unit 70), the detected outlet refrigerant temperature Te Based on this, the superheat degree on the outlet side of the ice making evaporator 50 can be grasped. Therefore, in the present embodiment, the degree of superheat can be grasped from the outlet refrigerant temperature Te without detecting the refrigerant temperature at the inlet of the ice making evaporator 50. The opening degree control of the electronic expansion valve 40 will be described in detail later.

  Moreover, as a control structure of the auger type ice making machine 100, as shown in FIG. 3, in addition to the control part 60 which consists of CPU, ROM61 and RAM62 are provided. The control unit 60 makes a predetermined determination based on input signals from the ambient temperature sensor 71, the refrigerant temperature sensor 72, and the ice storage amount detection switch 91 of the ice making cylinder 81 (see FIG. 2), and the cooling unit 70 (see FIG. 1). The compressor 10, the blower 21, the electronic expansion valve 40, and the auger motor 86 (see FIG. 2) of the ice making unit 80 (see FIG. 2) are controlled to appropriately drive various functional components. ing.

  The ROM 61 includes a first opening degree (initial opening degree) table 101 (see FIG. 5) and a second opening degree table 102 (see FIG. 6), which will be described later, in addition to the control program executed by the control unit 60. Stored. The RAM 62 is used for temporarily storing control parameters (history such as the ambient temperature Ta, the outlet refrigerant temperature Te, and the opening degree (number of pulses) of the electronic expansion valve 40) used when the control program is executed. Used as memory.

  Here, in this embodiment, the following opening degree control of the electronic expansion valve 40 is performed based on a command from the control unit 60 (see FIG. 3) during the ice making operation.

  Specifically, FIG. 4 shows that the ice storage chamber 84 is compensated for the insufficient ice storage amount from the standby state where the ice storage is completed (the ice storage chamber 84 (see FIG. 2) is full) and the operation is stopped. An example of the opening degree control pattern during the cycle operation in which the ice making operation is resumed is shown in FIG. In the cycle operation of the present embodiment, it is assumed that the opening degree of the electronic expansion valve 40 at the start of the ice making operation is fully open, and the ambient temperature Ta in the vicinity of the ice making evaporator 50 is, for example, 32 ° C. When the ice making operation is resumed at time t0, the first opening V1 (110 (stepping motor 40a (see FIG. 1) for driving) is set with the opening of the electronic expansion valve 40 as the initial opening at time t1. The pulse number is changed to a relative value when the number of pulses when Ta ≧ 41 ° C. is set to 100. Then, after maintaining the state of the first opening V1 for a time Δt1 (for example, 90 seconds), the next time t2 , The outlet refrigerant temperature Te of the ice making evaporator 50 detected by the refrigerant temperature sensor 72 and the ambient temperature Ta detected by the ambient temperature sensor 71 at the start of operation (time t0). Control is performed to change the degree from the first opening V1 (110 (relative value)), which is the initial opening, to the second opening V2 (90 (relative value)). Time Δt2 ( After maintaining for 120 seconds, for example, after time t3, fine adjustment control is performed to finely control the opening of the electronic expansion valve 40 so that the outlet refrigerant temperature Te becomes the target temperature Tg.

  That is, in this embodiment, before the opening degree of the electronic expansion valve 40 is finely fine-tuned and controlled so that the outlet refrigerant temperature Te becomes the final target temperature Tg (the section from time t3 to t4 is controlled). The two-stage opening change control of the first opening V1 (time t1) and the second opening V2 (time t2) is performed from the fully open state. Below, the detail of the determination method of 1st opening degree (initial opening degree) V1 and 2nd opening degree V2 is demonstrated.

  First, a method for determining the first opening (initial opening) V1 will be described. In the present embodiment, based on the ambient temperature Ta at the start of operation detected by the ambient temperature sensor 71, the first opening V1 as the initial opening is determined. More specifically, the first opening V1 and the outlet refrigerant temperature (first opening changing temperature) Te1 to be changed to the first opening V1 are determined in advance based on the ambient temperature Ta at the start of operation. It is configured. The first opening change temperature Te1 is an example of the “first opening change temperature” in the present invention. In this case, the first opening degree V1 (the number of pulses for driving the stepping motor 40a (see FIG. 1)) is determined based on the first opening degree table 101 as shown in FIG. In the first opening degree table 101 shown in FIG. 5, the ambient temperature Ta at the start of operation used for determining the first opening degree V1 is five temperature ranges (Ta ≦ 10 ° C., 11 ° C. ≦ Ta ≦ 20 ° C., 21 ° C. ≦ Ta ≦ 30 ° C., 31 ° C. ≦ Ta ≦ 40 ° C., Ta ≧ 41 ° C.). The detected ambient temperature Ta is rounded off to the first decimal place to determine which one of the temperature ranges of the first opening degree table 101 falls. For each of these five temperature ranges, a first opening V1 (number of pulses) and an outlet refrigerant temperature (first opening changing temperature) Te1 to be changed to the first opening V1 are set.

  That is, the first opening degree V1 (number of pulses) is individually set as 100, 110, 120, 130, 140 according to five temperature ranges of the ambient temperature Ta. The number of pulses shown in FIG. 5 is the number of pulses as a relative numerical value when the number of pulses of Ta ≧ 41 ° C. is 100 as described above.

  Further, in the first opening degree table 101, the first opening changing temperature Te1 is set to Tg + α1 (° C.) in two temperature ranges where the ambient temperature Ta is Ta ≦ 10 ° C. and 11 ° C. ≦ Ta ≦ 20 ° C., In three temperature ranges of 21 ° C. ≦ Ta ≦ 30 ° C., 31 ° C. ≦ Ta ≦ 40 ° C., and Ta ≧ 41 ° C., the first opening change temperature Te1 is set to Tg + α2 (° C.). Here, Tg is a target temperature of the outlet refrigerant temperature Te, and α1 <α2. Using such first opening table 101, the outlet refrigerant temperature (first opening) to be changed to the initial opening (first opening) V1 and the first opening V1 based on the ambient temperature Ta (32 ° C.). (Degree change temperature) Te1 is determined. In the example shown in FIG. 4, the first opening degree V1 is determined to be 110 (relative value) based on the first opening degree table 101 (see FIG. 5), and is used to change to the first opening degree V1. The first opening change temperature Te1 serving as a trigger (starting point) is determined as Tg + α2 (° C.).

  In the present embodiment, the change to the initial opening (first opening) V1 using the outlet refrigerant temperature Te (first opening changing temperature Te1) as a trigger instead of the passage of a fixed time is as follows. Depending on the reason. That is, when the ice making operation is started in a state where the auger type ice making machine 100 is cooled by the influence of the environmental temperature or the like, the outlet refrigerant temperature Te immediately decreases to a predetermined temperature. In this case, if control is performed to uniformly change the opening of the electronic expansion valve 40 to the first opening V1 (initial opening) after a certain fixed time from the start of the ice making operation, before the fixed time elapses ( Before the change to the first opening degree V1, the liquid-rich refrigerant having a small dryness (containing a relatively large amount of liquid phase) has already flowed too much into the ice making evaporator 50 (evaporation pipe 51). Therefore, in the present embodiment, a method is used in which the outlet refrigerant temperature Te is changed to the first opening degree V1 based on the fact that the outlet refrigerant temperature Te has decreased to the first opening degree changing temperature Te1 instead of time. Thereby, even when the ice making operation is started in a state where the apparatus main body is cooled, the opening degree of the electronic expansion valve 40 is the timing at which the outlet refrigerant temperature Te is lowered to the first opening degree changing temperature Te1 (time in FIG. 4). Since the opening degree is changed to the first opening degree V1 at t1), it is prevented as much as possible that the liquid-rich refrigerant having a small dryness flows too much into the ice making evaporator 50 before changing to the first opening degree V1.

  Next, a method for determining the second opening degree V2 will be described. The second opening V2 (number of pulses for driving the stepping motor 40a (see FIG. 1)) is set (determined) based on the second opening table 102 as shown in FIG. That is, in the present embodiment, the second opening V2 includes the ambient temperature Ta at the start of operation (time t0) and the ice making evaporator 50 after Δt1 seconds after changing to the first opening (initial opening) V1. And the outlet refrigerant temperature Te. More specifically, in the second opening degree table 102, the ambient temperature Ta at the start of operation used for determining the second opening degree V2 is Ta ≦ 10 ° C., 11 ° C. ≦ 11 similarly to the first opening degree table 101. The temperature is divided into five temperature ranges of Ta ≦ 20 ° C., 21 ° C. ≦ Ta ≦ 30 ° C., 31 ° C. ≦ Ta ≦ 40 ° C., and Ta ≧ 41 ° C. As in the case of the first opening degree table 101, the detected ambient temperature Ta is rounded off to the first decimal place to determine which one of the temperature ranges of the second opening degree table 102 is applicable. It is comprised so that.

  Further, as shown in FIG. 6, the outlet refrigerant temperature Te (second opening change temperature Te2) used for determining the second opening V2 is also set to Te2 ≧ for each of the five temperature ranges of the ambient temperature Ta. Tg + β4 (° C.) (Te2: high temperature), Tg + β1 (° C.) ≦ Te2 ≦ Tg + β2 (° C.) (Te2: medium high temperature), Tg-β2 (° C.) ≦ Te2 ≦ Tg-β1 (° C.) (Te2: medium low temperature), And it is divided into four temperature ranges A to D of Te2 ≦ Tg−β3 (° C.) (Te2: low temperature). Here, Tg is a target temperature of the outlet refrigerant temperature Te, and 0 <β1 <β2 <β3 <β4. Also in this case, when the detected outlet refrigerant temperature Te (Te2) is in the range between the ranges A and B and in the range between the ranges C and D, the first decimal place is rounded off. Thus, it is determined that any one of the four ranges A to D is applicable. Further, when the outlet refrigerant temperature Te (Te2) is in the range between the range B and C (Te2: suitable temperature) (when rounded off and determined as Tg−β1 (° C.) <Te2 <Tg + β1 (° C.)). Is set as a temperature range in which the second opening degree V2 is not determined in the control program. That is, when this temperature range (Tg−β1 (° C.) <Te2 <Tg + β1 (° C.)) is satisfied, it is determined that the cooling performance (cooling performance) at the first opening degree V1 is appropriate, and the second Without being changed to the opening degree V2, the state of the first opening degree V1 is immediately shifted to fine adjustment control for finely controlling the opening degree of the electronic expansion valve 40.

  In the second opening degree table 102, the second opening degree V2 (stepping motor 40a (see FIG. 1)) is driven in accordance with the combination of the ambient temperature Ta and the outlet refrigerant temperature Te (second opening degree changing temperature Te2). The number of pulses to be set) is set individually as 90 to 160 (relative value). Note that the opening degree of the electronic expansion valve 40 is set to increase (increase) as the number of the relative value of the number of pulses increases. In the example illustrated in FIG. 4, the ambient temperature Ta at the start of operation is 32 ° C., and the outlet refrigerant temperature Te (second opening degree change temperature Te2) at time t2 is Tg−γ1 (° C.). From the point (assumed to be included in the range D (Te2: low temperature)), the second opening degree V2 is determined as (90 (relative value)).

  Here, in this embodiment, in addition to the change to the first opening (initial opening V1), the reason for performing the two-stage control of the change to the second opening V2 will be described. As described above, since the electronic expansion valve 40 has a valve body portion (orifice) that is mechanically opened and closed, individual differences (for individual products) due to processing errors and assembly errors of the valve body portion ( There is a disadvantage that the refrigerant circulation amount varies due to variations in the electronic expansion valve 40. Due to variations in the components of the cooling system 70 such as the electronic expansion valve 40 and the refrigerant flow rate, the predetermined target temperature Tg is required unless the opening is significantly changed from the initial opening (first opening) V1. (See FIG. 4) may not be reached. In this case, if control is performed to finely adjust the opening from the first opening V1 as in the prior art, it takes time from the start of the ice making operation to the target evaporator temperature (target temperature Tg), and as a result. It takes time to stabilize the ice condition (ice quality) during ice making. Therefore, in the present embodiment, the first opening is based on the change in the outlet refrigerant temperature Te during a predetermined time Δt1 (for example, 90 seconds) from the time t1 to the time t2 after the change to the first opening (initial opening) V1. It is determined whether or not the cooling performance (cooling characteristic) of the ice making evaporator 50 at the degree V1 is appropriate, and the second opening degree V2 is determined and changed based on the determination result so as to perform the two-stage control. It is composed.

  In the example shown in FIG. 4, at the first opening V1, the outlet refrigerant temperature Te is changed from Tg + α2 (° C.) (time t1) to Tg−γ1 (° C.) (time t2) (second opening change temperature Te2: low temperature). ), The electronic expansion valve 40 is determined to be too open (throttle is insufficient), so that the first opening at time t2 is made using the second opening table 102 (see FIG. 6). Change control for switching to the second opening degree V2 (90 (relative value)) smaller than the degree V1 is performed. As a result, the electronic expansion valve 40 is throttled by 20 pulses, and the outlet refrigerant temperature Te is suppressed from decreasing so far, and on the contrary, the tendency is increased. That is, as a result of the change to the first opening V1 (110 (relative value)) at time t1, a liquid-rich refrigerant with a small dryness flows through the evaporation pipe 51 (see FIG. 2), and at the outlet of the ice making evaporator 50 Since it was determined that the predetermined degree of superheat was not obtained, it is determined that the cooling performance of the ice making evaporator 50 has been decreasing. Based on this determination, the degree of superheat is hardly obtained as a result of reducing (decreasing) the opening to the second opening V2 (90 (relative value)) by the control unit 60 (see FIG. 3) at time t2. The cooling performance of the ice making evaporator 50 is adjusted so that a more appropriate degree of superheat can be obtained from the state.

  Further, in this embodiment, the fine adjustment control after changing the temperature range (control target temperature range) of the outlet refrigerant temperature Te to the target temperature Tg during the change control to the second opening V2 to the second opening V2. It is set to be larger than the temperature range (control target temperature range) with respect to the target temperature Tg of the outlet refrigerant temperature Te at that time.

  In the present embodiment, based on the ambient temperature Ta detected by the ambient temperature sensor 71 at the start of operation (time t0), in addition to the first opening (initial opening) V1 and the second opening V2, The final target temperature Tg is also determined. In this case, the target temperature Tg is determined using a table or an arithmetic expression (not shown) based on the ambient temperature Ta at the start of operation.

  In the cycle operation shown in FIG. 4, the ice storage chamber 84 (see FIG. 2) is full at a time t4 when about 10 minutes have elapsed from the start of operation (time t0), and the detection plate 90a is raised to a predetermined height position to store the ice storage amount. The ice making operation is stopped by switching the detection switch 91 (see FIG. 2) to the off state. Thereby, one cycle operation is completed.

  Further, in addition to using the above-described two-stage opening change control of the electronic expansion valve 40 during the cycle operation shown in FIG. 4, no ice pieces are stored in the ice storage chamber 84 (see FIG. 2). It can also be used during pull-down operation (see FIG. 7) where ice making operation is started from the state.

  In the pull-down operation shown in FIG. 7, when the ice making operation is started at time t0, the opening of the electronic expansion valve 40 is fully opened, and the ambient temperature Ta in the vicinity of the ice making evaporator 50 is, for example, 35 ° C. Suppose that In this case, based on the first opening degree table 101 (see FIG. 5), the first opening degree V1 is determined to be 110 (relative value when the number of pulses when Ta ≧ 41 ° C. is 100), and this The outlet refrigerant temperature Te (first opening changing temperature Te1) serving as a trigger for changing to the first opening V1 is determined as Tg + α2 (° C.). Then, at the timing (time t1) acquired by the control unit 60 that the outlet refrigerant temperature Te is Tg + α2 (° C.), the opening degree of the electronic expansion valve 40 is changed from the fully open to the first opening degree V1 (110 (relative value)). Changed to As a result, the outlet refrigerant temperature Te that has fallen sharply from time t0 to time t1 turns to an upward trend as the first opening degree V1 is changed.

  During a predetermined time Δt1 (90 seconds) from the time t1 to the time t2 while maintaining the first opening V1 (110 (relative value)), the outlet refrigerant temperature Te once rises and then begins to fall again. And when it becomes time t2, the change value to the 2nd opening degree V2 is determined based on the 2nd opening degree table 102 (refer FIG. 6). That is, the ambient temperature Ta at the start of operation is 35 ° C., and the outlet refrigerant temperature Te (second opening change temperature Te 2) at time t 2 is Tg + γ 2 (° C.) (range B (Te 2: medium 2), the second opening degree V2 is determined as (115 (relative value)). Immediately after the determination of the second opening V2, the opening of the electronic expansion valve 40 is changed (enlarged) from the first opening V1 (110 (relative value)) to the second opening V2 (115 (relative value)). Is done. That is, since the opening degree of the electronic expansion valve 40 is expanded by 5 pulses at the timing of time t2, the outlet refrigerant temperature Te starts to further decrease from around Tg + γ2 (° C.).

  Further, after maintaining the state of the second opening degree V2 for a time Δt2 (for example, 120 seconds), after the time t3, the opening degree of the electronic expansion valve 40 is set so that the outlet refrigerant temperature Te of the ice making evaporator 50 becomes the target temperature Tg. Is finely controlled. The outlet refrigerant temperature Te approaches the target temperature Tg after 30 minutes or more have elapsed from the start of operation (time t0), and ice is smoothly formed in the ice making cylinder 81 and is sequentially pushed out into the ice storage chamber 84 and stored. . Then, at time t4, the ice storage chamber 84 is full, the detection plate 90a is raised to a predetermined height position, and the ice storage amount detection switch 91 (see FIG. 2) is switched to an off state, whereby the ice making operation is stopped. Thereby, the pull-down operation ends.

  Thus, in the example of the opening degree control at the time of pull-down operation shown in FIG. 7, as a result of changing to the first opening degree V1 (110 (relative value)) at the time t1, the refrigerant gradually has a large dryness (overheating). Since it was understood that a superheat degree higher than a predetermined superheat degree was obtained at the outlet of the ice making evaporator 50, the ice making evaporation was performed. It is determined that the cooling performance of the vessel 50 has been decreasing. Based on this determination, the controller 60 (see FIG. 3) expands (increases) the opening to the second opening V2 (115 (relative value)) at time t2, so that the degree of superheat is more than necessary. The cooling performance of the ice making evaporator 50 is adjusted in a direction in which a more appropriate degree of superheat can be obtained from the above state.

  Next, with reference to FIGS. 1-8, the opening degree control process flow of the control part 60 at the time of ice making operation (cycle operation and pull-down operation) by the auger type ice making machine 100 by this embodiment is demonstrated.

  As shown in FIG. 8, first, in step S1, the control unit 60 (see FIG. 3) determines whether or not there is an operation start request, and this process is performed until it is determined that there is an operation start request. Repeated. This operation start request is based on the fact that the ice storage amount detection switch 91 (see FIG. 2) is in an ON state because the ice storage amount in the ice storage chamber 84 is less than the predetermined amount and the detection plate 90a has not reached the upper predetermined position. Based on this, “Yes” is determined.

  If it is determined in step S1 that there is an operation start request, the ambient temperature Ta in the apparatus near the ice making evaporator 50 (see FIG. 1) is acquired by the control unit 60 in step S2, as shown in FIG. . That is, the current ambient temperature Ta (at the start of the ice making operation) acquired by the ambient temperature sensor 71 (see FIG. 1) is acquired. In addition, when the control part 60 judges that there exists a driving | operation start request | requirement, the blower 21 (refer FIG. 1) for the compressor 10 (refer FIG. 1) and the gas cooler 20 in parallel with the opening degree control process shown in FIG. Start up.

  In step S3, an initial opening degree (first first opening degree) of the electronic expansion valve 40 is obtained based on the acquired ambient temperature Ta using the first opening degree table 101 (see FIG. 5) stored in the ROM 61 (see FIG. 3). The opening degree V1) is determined by the control unit 60. In step S3, the target temperature Tg is also determined based on the acquired ambient temperature Ta. Subsequently, in step S4, the outlet refrigerant temperature (first opening changing temperature) Te1 when changing to the first opening V1 based on the first opening table 101 (see FIG. 5) is, for example, Tg + α2 (° C.). It is determined.

  Then, as shown in FIG. 8, in step S <b> 5, the current value of the outlet refrigerant temperature Te of the evaporation pipe 51 is acquired by the control unit 60. In step S6, the controller 60 determines whether or not the current outlet refrigerant temperature Te is the first opening change temperature Te1. If the outlet refrigerant temperature Te is different from Te1 (Tg + α2 (° C.)), the process returns to step S5, the outlet refrigerant temperature Te is acquired again, and the determination in step S6 is similarly repeated. When it is determined in step S6 that the outlet refrigerant temperature Te is equal to the first opening change temperature Te1 (Tg + α2 (° C.)), in step S7, the opening degree of the electronic expansion valve 40 is changed from the fully open state. Control to be changed to the first opening V1 as the initial opening is performed. In the ice making operation stop state (standby state), the opening degree of the electronic expansion valve 40 is set to fully open, and when the operation is started from this state, the first opening degree is maintained after the fully open state is continued. (Initial opening) V1 is changed. That is, at the time t1 shown in FIG. 4 or FIG. 7, the opening degree of the electronic expansion valve 40 is changed from the fully opened state to the first opening degree V1 from the controller 60 (see FIG. 1) to the stepping motor 40a (see FIG. 1). A control signal corresponding to the number of pulses (the number of pulses corresponding to the difference between the number of fully open pulses and the number of pulses of the first opening V1 (110 (relative value))) is transmitted. Thereby, the stepping motor 40a is rotated and the electronic expansion valve 40 is changed to the first opening degree V1. The cooling unit 70 continues the cooling operation (ice making operation) for a while while the electronic expansion valve 40 is held at the first opening degree V1.

  Thereafter, as shown in FIG. 8, in step S8, the current value of the outlet refrigerant temperature Te of the evaporation pipe 51 is acquired again. In step S9, the control unit 60 determines whether or not a predetermined time Δt1 (for example, 90 seconds) has elapsed since the change to the first opening degree V1. If the predetermined time Δt1 has not elapsed, the process returns to step S8, the outlet refrigerant temperature Te is acquired again, and the determination in step S9 is repeated. When it is determined in step S9 that the predetermined time Δt1 has elapsed, in step S10, the outlet refrigerant is stored using the second opening degree table 102 (see FIG. 6) stored in the ROM 61 (see FIG. 3). It is determined whether or not the temperature Te (Te2) falls within any one of the temperature ranges A to D. If yes, in step S11, based on the acquired outlet refrigerant temperature Te (Te2) and the ambient temperature Ta. The second opening degree V2 of the electronic expansion valve 40 is determined.

  As shown in FIG. 8, in step S12, the controller 60 changes the opening degree of the electronic expansion valve 40 from the first opening degree V1 to the second opening degree based on the second opening degree table 102 (see FIG. 6). Control to be changed to V2 is executed. That is, the number of pulses for changing the opening degree of the electronic expansion valve 40 from the first opening degree V1 to the second opening degree V2 from the control unit 60 (see FIG. 1) to the stepping motor 40a (see FIG. 1). A control signal corresponding to the number of pulses corresponding to the difference between the number of pulses of the first opening V1 and the number of pulses of the second opening V2 is transmitted. Thereby, the stepping motor 40a is rotated, and the electronic expansion valve 40 is changed to the second opening degree V2.

  After the change to the second opening degree V2, in step S13, the control unit 60 determines whether or not a predetermined time Δt2 (for example, 120 seconds) has elapsed since the time of changing to the second opening degree V2 (time t2). In addition, this determination is repeated until a predetermined time Δt2 elapses. When it is determined in step S13 that the predetermined time Δt2 has elapsed, the process proceeds to fine adjustment control after step S14. When it is determined in step S10 that the obtained outlet refrigerant temperature Te (Te2) does not correspond to the temperature range A to D of the second opening degree table 102 (corresponds to an appropriate temperature between the ranges B and C). Without determining the second opening degree V2 (step S11), changing to the second opening degree V2 (step S12), and determining whether the predetermined time Δt2 has elapsed after the second opening degree V2 is changed (step S13). Then, the process proceeds to fine adjustment control after step S14. In step S14, the refrigerant temperature sensor 72 acquires the current outlet refrigerant temperature Te of the evaporation pipe 51.

  In step S15, the control unit 60 compares the current outlet refrigerant temperature Te with the target temperature Tg determined in step S3. As a result of the comparison, when it is determined that the current outlet refrigerant temperature Te is different from the target temperature Tg determined in step S3 (in the case of “Yes” determination), the opening degree of the electronic expansion valve 40 is the second opening degree in step S16. It is changed (increased or decreased) by a minute amount to an opening different from V2. When it is determined that the current outlet refrigerant temperature Te is substantially the same as the target temperature Tg determined in step S3 (in the case of “No” determination), the process returns to step S13 described above, and the same processing is repeated thereafter.

  Further, after the opening degree of the electronic expansion valve 40 is changed (corrected) in step S16, in step S17, it is determined by the control unit 60 (see FIG. 3) whether or not there is an operation stop request. This operation stop request is made when the ice storage amount detection switch 91 (see FIG. 2) is turned off because the ice storage operation increases the ice storage amount in the ice storage chamber 84 to a predetermined amount or more and the detection plate 90a reaches the upper predetermined position. “Yes” is determined based on the state. If it is not determined in step S16 that there is an operation stop request, the process returns to step S13, and the opening adjustment (fine adjustment) of the electronic expansion valve 40 based on the outlet refrigerant temperature Te is repeated. That is, fine adjustment control is performed every time Δt2 (120 seconds). If it is determined that there is an operation stop request, the opening control of the electronic expansion valve 40 is terminated and the ice making operation is stopped. In this case, the opening degree of the electronic expansion valve 40 is changed to a fully open state, and the driving of the compressor 10 and the blower 21 is also stopped. In the auger type ice making machine 100, the cooling unit 70 is operated by the opening control of the electronic expansion valve 40 as described above, and ice making is performed in the ice making unit 80.

  In the present embodiment, as described above, the controller 60 changes the opening of the electronic expansion valve 40 to the first opening V1 as the initial opening, and then the ice making evaporator 50 detected by the refrigerant temperature sensor 72. The opening degree of the electronic expansion valve 40 is changed from the first opening degree V1 to the second opening degree V2 on the basis of the outlet refrigerant temperature Te, and then the outlet refrigerant temperature Te of the ice making evaporator 50 is set to a predetermined target temperature Tg (FIG. 4), the opening degree of the electronic expansion valve 40 is controlled. Thereby, the opening degree of the electronic expansion valve 40 is set so that the outlet refrigerant temperature Te becomes the predetermined target temperature Tg after the change from the fully opened state to the first opening degree V1 (initial opening degree) (change control of only one step). Unlike the case where fine adjustment control is performed, before the fine adjustment control of the opening degree of the electronic expansion valve 40, the two-stage opening degree change control of the first opening degree V1 and the second opening degree V2 may be performed. it can. That is, after changing to the first opening degree V1 as the initial opening degree, further, variation in the components of the cooling unit 70 (for example, the electronic expansion valve 40 has) based on the detected outlet refrigerant temperature Te of the ice making evaporator 50. After performing a two-stage change control of determining a cooling characteristic (cooling performance) that fluctuates due to individual product differences, etc., and determining and changing the second opening V2 according to the determined cooling characteristic The target temperature Tg can be reached earlier by finely controlling the opening degree. As a result, even when there is variation (individual difference) as a product in the electronic expansion valve 40 or the like, the time required to reach the target temperature Tg can be shortened to quickly stabilize the ice state (ice quality). it can. As a result, the ice quality can be further stabilized.

  Further, if the auger type ice making machine 100 according to the present embodiment is mounted on a cup type vending machine, the ice condition (ice quality) can be quickly stabilized and the soft ice condition can be prevented from prolonging. It is possible to effectively prevent the quality of ice put into beverages to be sold due to freezing (freezing) between ice pieces.

  In the present embodiment, an ambient temperature sensor 71 that detects the ambient temperature Ta inside the auger type ice making machine 100 (inside the apparatus) is provided. Then, by using the second opening degree table 102 (see FIG. 6) by the control unit 60, the outlet refrigerant temperature Te (second opening degree changing temperature Te2) of the ice making evaporator 50 detected by the refrigerant temperature sensor 72. Based on the ambient temperature Ta detected by the ambient temperature sensor 71, the opening degree of the electronic expansion valve 40 is controlled to be changed from the first opening degree V1 to the second opening degree V2. As a result, not only the detected outlet refrigerant temperature Te of the ice making evaporator 50 but also the ambient temperature Ta inside the apparatus can be taken into consideration, so that the cooling characteristics of the cooling unit 70 can be determined. Can be determined more appropriately and change control can be performed.

  Further, in the present embodiment, the control unit 60 changes the first opening degree V1 based on the outlet refrigerant temperature Te (Te2) of the ice making evaporator 50 after a predetermined time Δt1 (see FIG. 4) has elapsed. The second opening degree table 102 (see FIG. 6) is referred to, and control is performed to change the opening degree of the electronic expansion valve 40 from the first opening degree V1 to the second opening degree V2. Thus, based on the outlet refrigerant temperature Te (second opening degree changing temperature Te2) obtained as a result of continuing the operation for the predetermined time Δt1, the cooling characteristic (cooling performance) is judged and changed to the second opening degree V2. Therefore, unlike the case of determining the cooling characteristic immediately after the change to the first opening degree V1, the determination of the cooling characteristic can be performed more accurately. Thereby, change control can be performed by more accurately determining the second opening degree V2.

  In the present embodiment, the temperature range of the refrigerant when the electronic expansion valve 40 is changed from the first opening V1 to the second opening V2 is set at the time of opening control after the change to the second opening V2. Since the outlet refrigerant temperature Te of the ice making evaporator 50 can be changed in a larger range by changing from the first opening degree V1 to the second opening degree V2 by making it larger than the temperature range of the refrigerant, the target temperature Tg can be reached earlier.

  In the present embodiment, the refrigerant temperature sensor 72 is attached to the outlet side of the ice making evaporator 50 to detect the outlet refrigerant temperature Te. Then, the control unit 60 performs control to change the electronic expansion valve 40 from the first opening V1 to the second opening V2 based on the outlet refrigerant temperature Te detected by the refrigerant temperature sensor 72. That is, it is possible to grasp in advance from the specifications of the cooling system (the specifications of the compressor 10 and the ice making evaporator 50, the specifications of the electronic expansion valve 40 (the flow characteristics of the valve body), the specifications of the refrigerant pipes 5a to 5d, and the refrigerant filling amount). In consideration of the refrigerant temperature in the vicinity of the inlet 51a of the ice making evaporator 50, the ice making evaporator 50 is circulated based on the outlet refrigerant temperature Te on the outlet side of the ice making evaporator 50 detected by the refrigerant temperature sensor 72. Since the degree of superheat of the refrigerant can be determined, it is possible to easily determine the cooling characteristics that vary due to variations in the components of the cooling system 70 based on the determined degree of superheat. Thereby, change control from the 1st opening degree V1 to the 2nd opening degree V2 can be performed easily. Further, by detecting only the outlet refrigerant temperature Te of the ice making evaporator 50 using one refrigerant temperature sensor 72, the temperature sensor for detecting the temperature of the refrigerant can be made one, so that the control unit 60 is included. The apparatus configuration of the cooling unit 70 can be simplified.

  Further, in the present embodiment, based on the fact that the outlet refrigerant temperature Te of the ice making evaporator 50 detected by the refrigerant temperature sensor 72 has become the first opening change temperature Te1 (see FIG. 4) by the control unit 60. Control is performed to change the opening degree of the electronic expansion valve 40 to the first opening degree V1 as the initial opening degree. As a result, even when the ice making operation is started in a state where the auger type ice making machine 100 is cooled, the outlet opening temperature Te is changed to the first opening degree V1 when the outlet refrigerant temperature Te drops to the first opening degree changing temperature Te1. Further, it is possible to prevent the liquid-rich refrigerant having a small dryness from flowing too much before the change to the first opening degree V1. Further, by making the fact that the outlet refrigerant temperature Te becomes the first opening change temperature Te1 as a starting point (trigger) when changing to the first opening V1, the ice making operation is performed in a state where the auger type ice making machine 100 is cooled. When the outlet refrigerant temperature Te immediately decreases to the first opening degree change temperature Te1 as soon as is started, it can be changed to the first opening degree V1 at an early stage without waiting for a certain period of time. The target temperature Tg can be reached earlier.

  In the present embodiment, based on the ambient temperature Ta near the ice making evaporator 50 detected by the ambient temperature sensor 71 by the control unit 60, the first opening V1 as the initial opening and the first opening The first opening change temperature Te1 to be changed to V1 is determined. Thereby, even when the state of the refrigeration cycle accompanying the ice making operation differs depending on the ambient temperature Ta in the vicinity of the ice making evaporator 50, the optimal first opening V1 (initial opening degree) of the electronic expansion valve 40 according to the ambient temperature Ta. ) And the first opening degree change temperature Te1 when changing to the first opening degree V1 can be determined.

  In the present embodiment, the control unit 60 determines the target temperature Tg based on the ambient temperature Ta in the vicinity of the ice making evaporator 50 detected by the ambient temperature sensor 71. Thereby, even when the state of the refrigeration cycle accompanying the ice making operation differs depending on the ambient temperature Ta of the auger type ice making machine 100, the optimum target temperature Tg for the outlet refrigerant temperature Te of the ice making evaporator 50 is set according to the ambient temperature Ta. Can be determined.

  In addition, in the present embodiment, by using carbon dioxide as a refrigerant, an auger type ice making machine 100 that does not destroy the ozone layer and has a low influence on the global environment as a low-temperature chamber effect gas unlike a fluorocarbon refrigerant is provided. Can do.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the above-described embodiment, the example in which the present invention is applied to the auger type ice making machine 100 mounted on a cup type vending machine that sells cold beverages has been shown, but the present invention is not limited to this. For example, the present invention may be applied to an auger type ice maker installed alone, or to an auger type ice maker unit that is incorporated in other equipment that can supply ice other than a cup type vending machine. The invention may be applied. The opening degree control of the electronic expansion valve of the present invention can be applied to a cooling device other than an auger type ice making machine.

  In the above embodiment, an example in which the first opening degree V1 and the second opening degree V2 are determined using the first opening degree table 101 and the second opening degree table 102, respectively, is shown. However, the present invention is not limited to this. I can't. In the present invention, the first opening degree V1 and the second opening degree V2 may be determined by calculation without using the first opening degree table 101 and the second opening degree table 102.

  In the above embodiment, the refrigerant temperature sensor 72 is attached to the refrigerant pipe 5d near the outlet 51b of the evaporation pipe 51 to detect the outlet refrigerant temperature Te of the ice making evaporator 50. Not limited. If it is a part of the refrigerant pipe 5d between the outlet part 51b of the ice making evaporator 50 and the internal heat exchanger 30 (a part on the outlet side of the ice making evaporator 50), the refrigerant temperature sensor 72 is slightly separated from the outlet part 51b. You may attach to a position. However, it is preferable to attach the refrigerant temperature sensor 72 in the vicinity of the outlet portion 51b of the evaporation pipe 51 because the temperature of the outlet portion 51b of the evaporation pipe 51 can be detected more accurately.

  In the above embodiment, only the outlet refrigerant temperature Te of the ice making evaporator 50 is detected and the second opening degree V2 is determined based on the result. However, the present invention is not limited to this. For example, in addition to the outlet refrigerant temperature, the inlet refrigerant temperature of the evaporation pipe 51 may also be detected, and the second opening degree may be determined based on the detection results of both the inlet refrigerant temperature and the outlet refrigerant temperature.

  Moreover, in the said embodiment, when determining the 2nd opening degree V2 of the electronic expansion valve 40 using the 2nd opening degree table 102, the vicinity of the ice making evaporator 50 at the time of ice making operation start (time t0 in FIG. 4) However, the present invention is not limited to this. For example, when determining the second opening V2, the ambient temperature Ta in the vicinity of the ice making evaporator 50 at the time of determining the second opening V2 (time t2 in FIG. 4) may be used.

  Moreover, in the said embodiment, when determining target temperature Tg, it shows about the example which determined target temperature Tg based on ambient temperature Ta of the vicinity of the ice making evaporator 50 at the time of ice making operation start (time t0 in FIG. 4). However, the present invention is not limited to this. When determining the target temperature Tg, for example, the ambient temperature Ta in the vicinity of the ice making evaporator 50 at the time of determining the second opening degree V2 (time t2 in FIG. 4) may be used.

  Moreover, in the said embodiment, although the example which provided the internal heat exchanger 30 in the cooling unit 70 was shown, this invention is not limited to this. The present invention may be applied to an auger type ice making machine provided with a cooling unit in which the internal heat exchanger 30 is not provided.

  Moreover, in the said embodiment, although the example which comprised the cooling unit 70 using the 1-stage type compressor 10 was shown, this invention is not limited to this. The present invention may be applied to an auger type ice making machine equipped with a multistage compressor. The compressor may be any of a reciprocating compressor, a rotary compressor, a scroll compressor, a screw compressor, and the like. The compressor may be a capacity control system or a constant speed type.

  Moreover, in the said embodiment, although the example which operates the cooling unit 70 using a carbon dioxide refrigerant was shown, this invention is not limited to this. A natural refrigerant other than the carbon dioxide refrigerant may be used, or an alternative chlorofluorocarbon refrigerant having an ozone layer depletion coefficient of zero may be used. In this case, the opening degree (number of pulses) of the electronic expansion valve 40 defined in the first opening degree table 101 and the second opening degree table 102 is appropriately changed according to the refrigerant to be used.

  Further, in the above embodiment, the ambient temperature sensor 71 detects the ambient temperature Ta in the vicinity of the ice making evaporator 50, and based on the detected ambient temperature Ta, the first opening (initial opening) V1 and the second opening. The degree V2 and the target temperature Tg are determined, but the present invention is not limited to this. In the present invention, when the auger type ice making machine 100 is mounted on a cup type vending machine or the like, the ambient temperature of the cup type vending machine is detected by the ambient temperature sensor, and the detected ambient temperature is detected. The first opening (initial opening) V1, the second opening V2, and the target temperature Tg may be determined based on the temperature.

  Moreover, in the said embodiment, although the opening degree control process of the control part 60 was demonstrated using the flow drive type flowchart which processes in order along a process flow for convenience of explanation, this invention is not limited to this. . In the present invention, the opening degree control process of the control unit 60 may be performed by an event drive type (event driven type) process that executes the process in units of events. In this case, it may be performed by a complete event drive type or a combination of event drive and flow drive.

40 Electronic expansion valve 50 Ice making evaporator (evaporator)
60 Controller 71 Ambient temperature sensor (Ambient temperature detector)
72 Refrigerant temperature sensor (refrigerant temperature detector)
81 Ice making cylinder 82 Auger 100 Auger ice making machine (cooling device)
Ta Ambient temperature Te Outlet refrigerant temperature (refrigerant temperature of ice making evaporator, refrigerant temperature of evaporator)
Te1 First opening change temperature Tg Target temperature V1 First opening (initial opening)
V2 Second opening

Claims (10)

An ice making evaporator disposed on the outer periphery of an ice making tube in which an auger is disposed;
A refrigerant temperature detector for detecting a refrigerant temperature of the ice making evaporator;
An ambient temperature detector for detecting the ambient temperature;
An electronic expansion valve that controls the amount of refrigerant flowing into the ice making evaporator according to the opening;
A control unit for controlling the opening of the electronic expansion valve,
Wherein, said first opening degree of the electronic expansion valve with said detected by the ambient temperature detecting section on the basis of the ambient temperature to determine a first opening degree of the initial opening of the electronic expansion valve After changing to the opening , the opening of the electronic expansion valve is changed from the first opening to the second opening based on at least the refrigerant temperature of the ice making evaporator detected by the refrigerant temperature detector, and then An auger type ice making machine configured to control the opening degree of the electronic expansion valve so that the refrigerant temperature of the ice making evaporator becomes a predetermined target temperature. The ambient temperature detection unit is configured to detect an ambient temperature of the auger type ice making machine,
The control unit is configured to control the electronic expansion valve based on the refrigerant temperature of the ice making evaporator detected by the refrigerant temperature detecting unit and the ambient temperature of the auger type ice making machine detected by the ambient temperature detecting unit. The auger type ice making machine according to claim 1, wherein the auger type ice making machine is configured to perform control to change the opening degree from the first opening degree to the second opening degree.   The control unit changes the opening of the electronic expansion valve from the first opening to the second opening based on the refrigerant temperature of the ice making evaporator after a predetermined time has elapsed after changing to the first opening. The auger type ice making machine according to claim 1 or 2, wherein the auger type ice making machine is configured to be changed.   When changing to the second opening, the control unit changes the first opening to the second opening with respect to the refrigerant within the first temperature range with respect to the predetermined target temperature. When performing the control and controlling the opening of the electronic expansion valve after the change to the second opening, the second temperature range smaller than the first temperature range with respect to the predetermined target temperature. The auger type ice making machine according to any one of claims 1 to 3, wherein an opening degree of the electronic expansion valve is controlled so that the refrigerant reaches the predetermined target temperature. The refrigerant temperature detector is configured to detect a refrigerant temperature on the outlet side of the ice making evaporator,
The control unit changes the opening of the electronic expansion valve from the first opening to the second opening based on the refrigerant temperature at the outlet side of the ice making evaporator detected by the refrigerant temperature detecting unit. The auger type ice making machine according to any one of claims 1 to 4, wherein the auger ice making machine is configured to perform control.   The control unit sets the opening of the electronic expansion valve as the initial opening based on the fact that the refrigerant temperature of the ice making evaporator detected by the refrigerant temperature detection unit has reached the first opening change temperature. The auger type ice making machine according to any one of claims 1 to 5, wherein the auger ice making machine is configured to perform control to change to the first opening. The ambient temperature detection unit is configured to detect an ambient temperature of the auger type ice making machine,
Wherein, the first addition to the opening, on the basis of the ambient temperature of the auger type ice making machine which is detected by the ambient temperature detection unit, before Symbol the first opening changes to change the first opening It is configured to determine the temperature, the auger type ice making machine according to claim 6. The ambient temperature detection unit is configured to detect an ambient temperature of the auger type ice making machine,
The control unit is configured to determine the predetermined target temperature based on an ambient temperature of the auger type ice making machine detected by the ambient temperature detection unit. The auger type ice making machine as described in the item.   The auger type ice making machine according to any one of claims 1 to 8, wherein the refrigerant is carbon dioxide. A refrigerant temperature detector for detecting the refrigerant temperature of the evaporator;
An ambient temperature detector for detecting the ambient temperature;
An electronic expansion valve that controls the amount of refrigerant flowing into the evaporator according to the opening;
A control unit for controlling the opening of the electronic expansion valve,
Wherein, said first opening degree of the electronic expansion valve with said detected by the ambient temperature detecting section on the basis of the ambient temperature to determine a first opening degree of the initial opening of the electronic expansion valve After changing to the opening degree , the opening degree of the electronic expansion valve is changed from the first opening degree to the second opening degree based on at least the refrigerant temperature of the evaporator detected by the refrigerant temperature detecting unit, and then A cooling device configured to control an opening degree of the electronic expansion valve so that a refrigerant temperature of the evaporator becomes a predetermined target temperature.

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