JP2002323278A - Protection apparatus of auger type ice making machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the protection apparatus of an auger type ice making machine that can prevent excessive growth of ice, while continuing ice-making operation. SOLUTION: When a motor current I of a geared motor 7 that is detected by a current detector 14 reaches a current-set value It or higher, a control circuit 13 recognizes the generation of an overcurrent, and controls an inverter 12 so that the speed of a compressor 9 is reduced, thus causing the output of the compressor 9 to decrease and inhibiting the excessive growth of ice. When the motor current I decreases gradually and becomes lower than the current-set value It, the control circuit 13 controls the inverter 12, so that the speed of the compressor 9 becomes the speed in normal ice-making operation by regarding that an overload has been cancelled, thus restoring the output of the compressor 9 and continuing ice-making operation, as it is.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protection device for an auger type ice making machine, and more particularly to a device for preventing a hunting trouble of a geared motor for driving an auger.

[0002]

2. Description of the Related Art An auger-type ice making machine has a vertically long cylindrical refrigerating casing, and a cooling pipe constituting an evaporator of a refrigerating circuit is wound around an outer peripheral surface of the refrigerating casing. An auger having a blade is provided. Ice-making water is supplied to the inside of the freezing casing, and the ice grown on the inner peripheral surface of the freezing casing is scraped off by the rotation of the spiral blade, turns into flake-like ice, and upwards by a spiral action. Transported to A pressing head for forming ice into a desired shape and hardness is provided at an upper portion of the freezing casing.

However, if ice clogging, insufficient water supply, abnormalities in the refrigeration circuit, etc. occur inside the pressing head for any reason, the refrigeration casing will be overcooled. If the ice making machine continues to be driven in this state, overgrowth of ice occurs inside the freezing casing, and the pushing load of the auger increases, and an excessive load is applied to the geared motor that drives the auger. For this reason, after the auger that had rotated normally could not scrape the overgrown ice and reversed due to the impact, the auger again collided with the ice and started to rotate again, and thus the normal rotation There is a case where so-called hunting is repeatedly generated. When such hunting occurs, there is a fear that troubles such as breakage of gears in the geared motor and breakage of the auger may occur. Therefore, in the conventional auger type ice making machine, a temperature sensing tube is attached to the low pressure side of the compressor to monitor the temperature in the freezing casing, and when the temperature drops to the set value, the compressor is stopped to stop the ice making operation. There has been a method to prevent overgrowth of ice by doing so.

[0004]

However, in this method, the response is low, and it has been difficult to prevent overgrowth of ice. Also, if the temperature set value for stopping the compressor is set to a relatively high value in advance, the compressor can be stopped before the overgrowth of ice occurs. As a result, there is a problem that the efficiency of ice making is reduced. The present invention has been made to solve such a problem, and an object of the present invention is to provide a protection device for an auger-type ice making machine that can prevent ice from growing excessively while continuing the ice making operation.

[0005]

According to a first aspect of the present invention, there is provided a protection device for an auger type ice making machine, comprising: an inverter for driving and controlling a compressor; a current detector for detecting a motor current flowing through a geared motor; and a current detector. And a control circuit for controlling the inverter such that the output of the compressor is reduced when the motor current detected by the controller becomes equal to or more than a set value. Second
The protection device for an auger type ice making machine according to the invention includes an inverter for controlling the driving of the compressor, a temperature detector for detecting a refrigerant temperature at an outlet side of the cooling pipe, and a refrigerant temperature detected by the temperature detector being a predetermined value. And a control circuit for controlling the inverter so that the output of the compressor is reduced when the following conditions are satisfied. According to a third aspect of the present invention, there is provided a protection device for an auger type ice making machine, comprising: an inverter for driving and controlling a compressor; a current detector for detecting a motor current flowing through a geared motor; and a temperature for detecting a refrigerant temperature at an outlet side of a cooling pipe. A control circuit for controlling the inverter such that the output of the compressor is reduced when the motor current detected by the current detector is equal to or higher than a set value and the refrigerant temperature detected by the temperature detector is equal to or lower than a predetermined value. It is provided with.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Embodiment 1 FIG. FIG. 1 shows a main part of an auger-type ice maker provided with a protection device according to Embodiment 1 of the present invention. The auger-type ice maker has a freezing casing 1, and a cooling pipe 2 is wound around the outer peripheral surface thereof. Inside the freezing casing 1, an ice auger 3 having a spiral blade is rotatably supported by an upper bearing 4 and a lower bearing 5. The upper bearing 4 is fixed to the upper end of the freezing casing 1 by fixing bolts 6. The auger 3 is connected at its lower end to a DC brushless type geared motor 7, which scrapes ice grown on the inner peripheral surface of the freezing casing 1 to form a plurality of fixed blades 8 formed on the outer peripheral portion of the upper bearing 4. Transfer to

A compressor 9 is connected to an outlet side of the cooling pipe 2, a condenser 10 and an expansion valve 11 are sequentially connected to the compressor 9, and an inlet side of the cooling pipe 2 is connected to the expansion valve 11. These form a refrigeration circuit. An inverter 12 for driving and controlling the compressor 9 is connected to the compressor 9, and a control circuit 13 is connected to the inverter 12. Further, a current detector 14 is connected to the geared motor 7, and the current detector 14 is connected to the control circuit 13.

Next, the operation of the protection device for an auger type ice making machine according to this embodiment will be described. First, when the power of the auger type ice making machine is turned on, water is supplied to a float tank (not shown), and then the compressor 9 is driven by the control circuit 13 via the inverter 12, and the low temperature and low pressure The coolant is supplied and the geared motor 7 is driven to start the ice making operation. Thereby, ice making water is supplied from the float tank into the freezing casing 1, cooled by the cooling pipe 2, and ice grows on the inner peripheral surface of the freezing casing 1. The ice is scraped off by the rotation of the auger 3, turned into flake-like ice, transported upward by a spiral action, and formed into a desired shape and hardness by the fixed blade 8.

Along with such an ice making operation, the motor current I flowing through the geared motor 7 is detected by the current detector 14 and sent to the control circuit 13. In the control circuit 13, a current set value It for detecting an overcurrent generated when an overload acts on the geared motor 7 is set in advance, and the motor current I detected by the current detector 14 is When the current becomes equal to or greater than the current set value It, the control circuit 13 recognizes that an overcurrent has occurred, and controls the inverter 12 so that the rotation speed of the compressor 9 decreases. As a result, the output of the compressor 9 is reduced, the ability to generate ice in the refrigeration casing 1 is reduced, and the overgrowth of ice, which causes the overload of the geared motor 7, is suppressed. As a result, the load acting on the geared motor 7 is gradually reduced, and the motor current I flowing through the geared motor 7 decreases.

When the motor current I falls below the current setting value It, the control circuit 13 determines that the overload has been resolved and sets the inverter 12 so that the rotation speed of the compressor 9 becomes the rotation speed during normal ice making operation. Control. Thereby, the output of the compressor 9 is restored, and the ice making operation is continued as it is. As described above, the compressor 9 is driven and controlled by the inverter 12, and when the motor current I detected by the current detector 14 becomes equal to or more than the current set value It, the output of the compressor 9 is reduced. When the temperature falls below It, the output of the compressor 9 is returned to the value at the time of the normal ice making operation. Therefore, it is possible to prevent the ice from growing excessively while performing the continuous ice making operation.

Embodiment 2 FIG. FIG. 2 shows a main part of an auger-type ice maker provided with the protection device according to the second embodiment. The protection device according to the second embodiment is different from the protection device according to the first embodiment shown in FIG. 1 in that the refrigerant temperature T is set near the outlet pipe of the cooling pipe 2 instead of connecting the current detector 14 to the geared motor 7. A temperature detector 15 for detection is provided, and this temperature detector 15 is connected to a control circuit 13. If the inside of the refrigeration casing 1 becomes supercooled for some reason, the temperature of the refrigerant discharged from the outlet of the cooling pipe 2 decreases. Therefore, the control circuit 13 monitors the refrigerant temperature T detected by the temperature detector 15, and the refrigerant temperature T
When it becomes equal to or less than a predetermined value Tt set in advance, the control circuit 13 recognizes that a supercooling state has occurred, and controls the inverter 12 so that the rotation speed of the compressor 9 decreases. As a result, the output of the compressor 9 decreases, the overgrowth of ice is suppressed, and the refrigerant temperature T on the outlet side of the cooling pipe 2 gradually increases.

When the refrigerant temperature T detected by the temperature detector 15 exceeds a predetermined value Tt, the control circuit 13 determines that the supercooling has been eliminated and the rotational speed of the compressor 9 is reduced to the rotational speed during the normal ice making operation. The inverter 12 is controlled so that Thereby, the output of the compressor 9 is restored, and the ice making operation is continued as it is. As described above, when the refrigerant temperature T detected by the temperature detector 15 falls below the predetermined value Tt, the output of the compressor 9 is reduced, and when the refrigerant temperature T exceeds the predetermined value Tt, the output of the compressor 9 is reduced to the normal ice making. Since the value is restored to the value at the time of operation, it is possible to prevent the ice from growing excessively while performing the continuous operation of ice making.

Embodiment 3 FIG. 3 shows a main part of an auger-type ice maker provided with the protection device according to the third embodiment. The protection device according to the third embodiment is different from the device according to the first embodiment shown in FIG. 1 in that a temperature detector 15 for detecting the refrigerant temperature T is further provided near the outlet pipe of the cooling pipe 2,
The temperature detector 15 is connected to the control circuit 13 together with the current detector 14. The control circuit 13 monitors both the motor current I detected by the current detector 14 and the refrigerant temperature T detected by the temperature detector 15, and the motor current I
When the refrigerant temperature T becomes equal to or higher than the current set value It set in advance and the refrigerant temperature T becomes equal to or lower than the predetermined value Tt preset in the control circuit 13, the control circuit 13 And controls the inverter 12 so that the rotation speed of the compressor 9 decreases. As a result, the output of the compressor 9 decreases, the overgrowth of ice is suppressed, the motor current I flowing through the geared motor 7 decreases, and the refrigerant temperature T at the outlet side of the cooling pipe 2 gradually increases.

When the motor current I detected by the current detector 14 falls below the current set value It or when the refrigerant temperature T detected by the temperature detector 15 exceeds a predetermined value Tt, the control circuit 13 The inverter 12 is controlled so that the rotation speed of the machine 9 becomes the rotation speed during the normal ice making operation. Thereby, the output of the compressor 9 is restored, and the ice making operation is continued as it is. As described above, when the motor current I detected by the current detector 14 is equal to or more than the current set value It and the refrigerant temperature T detected by the temperature detector 15 becomes equal to or less than the predetermined value Tt, the output of the compressor 9 is reduced, If the motor current I is lower than the current set value It or if the refrigerant temperature T exceeds a predetermined value Tt, the output of the compressor 9 is returned to the value at the time of the normal ice making operation. Overgrowth of ice can be prevented.

When only the motor current I becomes equal to or higher than the current set value It while the refrigerant temperature T exceeds the predetermined value Tt, the auger 3 is not in a supercooled state but is in a supercooled state.
There is a fear that cutting may come into contact with the inner peripheral surface of the freezing casing 1. Conversely, if the refrigerant temperature T falls below the predetermined value Tt while the motor current I remains below the current set value It, a shortage of water supply due to clogging of a water supply valve, a failure of a float switch of a water supply tank, etc. Fear of. Therefore,
By monitoring both the motor current I detected by the current detector 14 and the refrigerant temperature T detected by the temperature detector 15 as in the third embodiment, not only the overgrowth of ice but also Can also be detected.

[0016]

As described above, according to the present invention, the compressor is driven and controlled by the inverter, and the motor current detected by the current detector is equal to or more than the set value or the temperature is detected by the temperature detector. Whether the refrigerant temperature falls below a predetermined value,
Alternatively, when the motor current detected by the current detector is equal to or more than a set value and the refrigerant temperature detected by the temperature detector is equal to or less than a predetermined value, the inverter is controlled by the control circuit so that the output of the compressor is reduced. Overgrowth of ice can be prevented while continuing the ice making operation. Therefore, it is possible to prevent troubles such as breakage of gears in the geared motor and breakage of the auger caused by overgrowth of ice while suppressing a decrease in ice making efficiency.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of an auger-type ice maker provided with a protection device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a main part of an auger ice maker provided with a protection device according to a second embodiment.

FIG. 3 is a block diagram showing a main part of an auger ice maker provided with a protection device according to a third embodiment.

[Explanation of symbols]

1 freezing casing, 2 cooling pipes, 3 augers, 4
Upper bearing, lower bearing, 6 fixing bolt, 7 geared motor, 8 fixed blade, 9 compressor, 10 condenser,
11 expansion valve, 12 inverter, 13 control circuit, 1
4 Current detector, 15 Temperature detector.

Claims (3)

[Claims] 1. A low-temperature and low-pressure refrigerant is supplied to a cooling pipe wound around an outer peripheral portion of a freezing casing by driving a compressor to generate ice on an inner wall portion of the freezing casing, and the ice is driven by a geared motor. An auger-type ice maker that protects the compressor by driving the compressor; a current detector that detects a motor current flowing through the geared motor; and a motor current that is detected by the current detector. And a control circuit for controlling the inverter so that the output of the compressor is reduced when the above is achieved. 2. A low-temperature and low-pressure refrigerant is supplied to a cooling pipe wound around an outer peripheral portion of a freezing casing by driving a compressor to generate ice on an inner wall portion of the freezing casing, and the ice is driven by a geared motor. In an auger-type ice maker protection device that scrapes with an auger, an inverter that drives and controls a compressor, a temperature detector that detects a refrigerant temperature at an outlet side of a cooling pipe, and a refrigerant temperature detected by the temperature detector A control circuit for controlling the inverter so that the output of the compressor falls below a predetermined value. 3. A low-temperature and low-pressure refrigerant is supplied to a cooling pipe wound around the outer periphery of the freezing casing by driving the compressor to generate ice on the inner wall of the freezing casing, and the ice is driven by a geared motor. In the auger-type ice machine protection device that is scraped by an auger, an inverter that drives and controls the compressor, a current detector that detects the motor current flowing through the geared motor, and a temperature detector that detects the refrigerant temperature at the outlet side of the cooling pipe Control for controlling the inverter so that the output of the compressor is reduced when the motor current detected by the current detector is equal to or higher than a set value and the refrigerant temperature detected by the temperature detector is equal to or lower than a predetermined value. A protection device for an auger-type ice maker, comprising a circuit.