JP3875159B2 - How to operate an automatic ice machine - Google Patents

Description

[0001]
The present invention relates to an operation method of an automatic ice making machine, and more particularly, in an automatic ice making machine that repeatedly stores an ice making operation and a deicing operation to store ice blocks in a stocker, in a stopped state in which the ice making-deicing operation is stopped. Electricity is supplied to each load due to an abnormality in the control circuit. The Case Is The present invention relates to a method of operating an automatic ice making machine that prevents excessive heating or cooling of the ice making unit by repeating cooling and heating of the ice making unit.
[0002]
[Prior art]
A jet type automatic ice maker that continuously produces a large number of ice blocks is provided with an evaporator connected to a refrigeration system composed of various members such as a compressor, a condenser, an expansion valve, etc. An ice making chamber that defines the ice making chambers, water that closes the ice making chambers so that the ice making chambers can be tilted and opened from below, and has a fountain hole corresponding to each ice making chamber, with an ice making water tank integrally provided at the bottom. With a dish. In the ice making operation, the refrigerant is circulated and supplied to the evaporator to forcibly cool the ice making chamber, and the ice making water in the ice making water tank is sprayed and supplied from the fountain hole of the water tray to the ice making chamber. Configured to generate ice blocks in the chamber. After ice making is completed, the ice removal operation is started, the water tray is tilted to open the ice making chamber, and hot gas (high-temperature refrigerant gas) is circulated and supplied to the evaporator by switching the hot gas valve in the refrigeration system. Then, the ice making chamber is heated. When the icing between the inner wall surface of the ice making chamber and the ice block is melted by the hot gas continuously supplied, the ice block falls from the ice making chamber by its own weight and is released and stored in the stocker.
[0003]
In the control circuit for controlling the operation of the automatic ice making machine, a fan motor operated to air-cool the condenser during ice making operation and a hot gas valve opened to circulate hot gas to the evaporator during deicing operation Are connected to the normally open contact or the normally closed contact of one control relay, and the fan motor is always operated or the hot gas valve is opened depending on the excitation or demagnetization state of the control relay. It is configured. In the automatic ice maker, when it is detected that the stocker is full of ice blocks, or when an abnormality such as a failure occurs, the ice making / deicing operation is stopped and a transition is made to a stop state in which ice blocks are not manufactured. At this time, the control relay is set to be in a demagnetized state so that the hot gas valve can be energized.
[0004]
[Problems to be solved by the invention]
In the control circuit, the power relay connected to the power source is configured to be demagnetized in the stopped state to open its normally open contact, and to cut off the supply of electricity to the compressor and other loads. However, if an abnormality occurs in which the normally open contact of the power relay is welded for some reason, the normally open contact of the power relay does not open even when controlled so as to be in the stopped state. Will be supplied. That is, while the compressor is operated, the hot gas valve is energized through the control relay to open the valve, and hot gas from the compressor is circulated and supplied to the evaporator to heat the ice making chamber. The
[0005]
Accordingly, the ice making chamber continues to be heated during the stop state, and the resin product such as the holder for attaching the ice making thermistor to the ice making chamber and the spacer for attaching the ice making chamber horizontally to the ice making machine body is melted or deformed. This causes inconvenience. For example, when the holder is deformed, the ice making thermistor does not reliably contact the ice making chamber, and appropriate temperature detection cannot be performed. When the spacer is deformed, the ice making chamber is tilted and is not in an appropriate position. If the ice lump is stopped due to full detection, the fullness is not detected or the operator returns to normal operation (ice making / deicing operation) when the power is turned on again. If this occurs, there is a risk that normal operation cannot be performed even after operation is resumed.
[0006]
In the stop state, when the control relay is set to be in a state where the fan motor can be energized, the refrigerant is continuously supplied to the evaporator when the above-described abnormality of the power supply relay occurs. This causes inconvenience that the chamber is excessively cooled. Further, if the circulation of the refrigerant continues in this manner, a large amount of frost may adhere to the expansion valve of the refrigeration system, leading to a failure.
[0007]
OBJECT OF THE INVENTION
In view of the above-described problems inherent in the conventional technology described above, the present invention has been proposed to suitably solve this problem, and prevents excessive heating and cooling of the ice making unit in a stopped state. It is an object of the present invention to provide an operation method of an automatic ice making machine that can perform normal operation when returning to ice making-deicing operation.
[0008]
[Means for Solving the Problems]
In order to overcome the above-mentioned problems and achieve the desired purpose suitably, the operation method of the automatic ice making machine according to the present invention is as follows:
During ice making operation, an ice block is generated by supplying a refrigerant from the refrigeration system to the evaporator disposed in the ice making unit, and after ice making is completed, the ice removal operation is performed and hot gas is supplied to the evaporator. In an automatic ice maker configured to deice ice blocks by heating the ice making unit,
In the stop state where the ice making-deicing operation is stopped, when electricity is supplied to each load due to an abnormality in the control circuit, the evaporator is based on the temperature detected by the temperature detecting means for detecting the temperature of the ice making unit. It is characterized in that the supply of the refrigerant and the supply of hot gas are repeated.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, the operation method of the automatic ice making machine according to the present invention will be described in detail below with reference to the accompanying drawings by giving a preferred embodiment.
[0010]
FIG. 1 shows an ice making mechanism of an automatic ice making machine according to an embodiment. In the ice making mechanism M, a mounting frame 10 disposed above a housing (not shown) is interposed via a resin spacer 12. An ice making chamber 14 serving as an ice making unit is horizontally disposed, and a plurality of ice making chambers 14a opening downward are defined in a grid pattern. Further, an evaporator 18 connected to a refrigeration system 16 described later is closely and meanderingly arranged on the upper surface of the ice making chamber 14, and the ice making chamber 14a is forced by circulating a refrigerant in the evaporator 18 during ice making operation. In addition to cooling, the ice making chamber 14a is heated by circulating hot gas during the deicing operation.
[0011]
A water dish 22 having an ice making water tank 20 for storing a predetermined amount of ice making water is pivotally supported by a support shaft 24 immediately below the ice making chamber 14. The water tray 22 is horizontally positioned (ice making position) so as to be close to the ice making chamber 14 during the ice making operation, and is held so as to close the ice making chamber 14a of the ice making chamber 14 from below. The tilting mechanism is actuated by the actuator motor AM, tilts in the clockwise direction in FIG. 1 about the support shaft 24, and stops in an oblique state (deicing position), thereby opening the ice making chamber 14a. Yes. The tilt mechanism includes a drive arm 26 that is disposed on the output shaft of the actuator motor AM and extends in the radial direction, a front end of the drive arm 26 and a front end of the water dish 22 (the end opposite to the pivot side). And a coil spring 28 that is elastically engaged with each other. During the ice making operation, the water tray 22 is configured to be held by the elasticity of the coil spring 28 at a horizontal ice making position that closes the ice making chamber 14 from below.
[0012]
The drive arm 26 is provided with a lever piece 26a that extends in the radial direction with respect to the output shaft at a position away from the engagement position of the coil spring 28. Changeover switch SW on the movement trajectory of drive arm 26 and lever piece 26a ₂ Is rotated by the operation of the actuator motor AM rotating in the forward rotation direction (direction allowing movement of the water tray 22 to the deicing position) in accordance with the deicing operation (forward rotation in the counterclockwise direction in FIG. 1). ) Lever piece 26a is changeover switch SW ₂ Is switched from the normal rotation side to the reverse rotation side, the microcomputer PC that controls the operation of the automatic ice making machine is set to stop the actuator motor AM and to stop and hold the water dish 22 at the inclined deicing position. Further, the switch SW is rotated by the drive arm 26 which rotates in the clockwise direction by the reverse rotation of the actuator motor AM after the deicing operation is completed. ₂ Is switched from the reverse rotation side to the normal rotation side, the microcomputer PC is set to stop the actuator motor AM and stop and hold the water tray 22 at the horizontal ice making position.
[0013]
An ice making thermistor (temperature detecting means) TH is disposed at an appropriate position of the ice making chamber 14 via a resin holder (not shown), and the thermistor TH generates square ice blocks in all ice making chambers 14a by the ice making operation. When detecting the ice making completion temperature, the microcomputer PC switches from the ice making operation to the deicing operation, and the deicing operation completes the deicing of the ice block from the ice making chamber 14 to remove the temperature rise (removal). When the ice making thermistor TH detects the (ice completion temperature), the microcomputer PC is set to switch from the deicing operation to the ice making operation. Further, when the ice making thermistor TH detects the ice making completion temperature, the microcomputer PC is set to switch (open) the hot gas valve HV of the refrigeration system 16 so that the hot gas flows through the evaporator 18. Further, when the automatic ice making machine is in a stop state where the ice making / deicing operation is stopped and the ice block is not produced as described later, when the ice making thermistor TH detects the upper limit temperature at the time of abnormality, The microcomputer PC closes the hot gas valve HV to supply the refrigerant to the evaporator 18 and operates the fan motor FM described later, and when the ice making thermistor TH detects the lower limit temperature at the time of abnormality. The microcomputer PC is set to open (ON) the hot gas valve HV to supply hot gas to the evaporator 18 and to stop the fan motor FM (see FIG. 5). In the embodiment, a predetermined temperature set higher than the deicing completion temperature is used for the upper limit temperature at the time of abnormality, and the same temperature as the ice making completion temperature is used for the lower limit temperature at the time of abnormality.
[0014]
In the portion of the water dish 22 facing the ice making chamber 14, a fountain hole for injecting ice making water to each of the ice making chambers 14 a and uniced water adjacent to the fountain hole are supplied to the ice making water tank 20. A large number of return holes (both not shown) for recovery are formed. Further, a pump motor PM is disposed on the side of the ice making water tank 20, and the motor PM is operated to inject and supply ice making water in the tank into each ice making small chamber 14a from the numerous fountain holes. Is done. The uniced water is returned to the ice making water tank 20 through the return hole and is used for recirculation.
[0015]
As shown in FIG. 2, a water supply pipe 30 communicating with an external water system (not shown) is located above the water tray 22 and opens. The water supply pipe 30 is provided with a water supply valve WV. When the water supply valve WV is opened (ON), tap water is supplied to the upper surface of the water dish, and this water is recovered from the return hole to the ice making water tank 20 to be used for the next ice making. Configured to be stored as water. The water supply valve WV is opened (ON) when the ice making thermistor TH detects the deicing completion temperature, and when the water tray 22 arrives at the ice making position (selection switch SW ₂ It is set to continue to open and supply ice-making water for a set time of a water supply timer (not shown) that starts when the contact point of (1) is switched to the “ab” side. The water supply valve WV is opened (ON) for a predetermined time (set time of the ice melting timer) even when the water tray 22 arrives at the deicing position after switching from the ice making operation to the deicing operation. It is set to wash away the ice adhering to the upper surface of the water tray 22 by sprinkling tap water on the upper surface of the water tray (see FIG. 4).
[0016]
An ice storage chamber 32 is defined below the ice making mechanism M in the housing, and ice blocks produced by the ice making mechanism M are stored in the ice storage chamber 32. The ice storage chamber 32 has an ice storage switch SW that operates according to the amount of ice blocks stored in the ice storage chamber 32. ₁ Is disposed. And ice storage switch SW by ice block ₁ When the microcomputer PC is activated and enters the detection state (ON), the microcomputer PC determines that the ice block is full, stops the ice making / deicing operation, shifts to a stop state where the ice block is not manufactured, and the ice block is consumed. Ice storage switch SW ₁ When is returned to the original non-detection state (OFF), operation control is performed so that the ice making / deicing operation is resumed. In the stop state due to the ice storage detection, the ice making / deicing operation is set to resume even when the operator turns on the power again.
[0017]
In the refrigeration system 16 of the automatic ice making machine shown in FIG. 2, the vaporized refrigerant compressed by the compressor CM is condensed and liquefied by the condenser 36 through the discharge pipe 34, and decompressed by the expansion valve 38. By expanding and evaporating all at once, heat exchange with the ice making chamber 14 is performed to cool each ice making chamber 14a to below the freezing point. The vaporized refrigerant evaporated in the evaporator 18 is configured to repeat a cycle of returning to the compressor CM via the suction pipe 40. In addition, the code | symbol FM in a figure shows the fan motor which is drive | operated at the time of the ice making operation which supplies a refrigerant | coolant to the evaporator 18, and cools the condenser 36 by air.
[0018]
Further, a hot gas pipe 42 is branched from the discharge pipe 34 of the compressor CM, and the hot gas pipe 42 communicates with the inlet side of the evaporator 18 via a hot gas valve HV. The hot gas valve HV is opened (ON) during the deicing operation so that the hot gas discharged from the compressor CM is bypassed to the evaporator 18 via the hot gas pipe 42, and each ice making chamber 14a is added. Each ice block is dropped by its own weight by melting the peripheral surface of the ice block generated in the small chamber by heating. The hot gas flowing out from the evaporator 18 is configured to return again from the suction pipe 40 to the compressor CM.
[0019]
FIG. 3 shows a control circuit of the automatic ice making machine according to the embodiment, and only the main components related to the present invention will be described, and the description of the other parts will be omitted. Relay X ₁ , X ₂ , X _Three , X _Four An ice storage switch SW is connected to the microcomputer PC (not shown). ₁ And an ice making thermistor TH. The changeover switch SW ₂ The fixed contact “b” on the forward rotation side of the ₁ Normally open contact X ₁ -A is connected to the forward contact of the actuator motor AM through the switch a ₂ The fixed contact “c” on the reverse side of the ₁ Normally closed contact X ₁ -B is connected to the contact on the reverse side of the actuator motor AM. Changeover switch SW ₂ The contact “b” on the forward rotation side of the ₁ Normally closed contact X ₁ -B is connected to the pump motor PM.
[0020]
The changeover switch SW ₂ Relay X connected to the movable contact "a" ₂ Normally open contact X ₂ -A is connected to the fan motor FM and the relay X ₂ Normally closed contact X ₂ The hot gas valve HV is connected to -b. That is, relay X ₂ In the demagnetization state, the fan motor FM is stopped (OFF), the hot gas valve HV is opened (ON), and the relay X ₂ In the excited state, the fan motor FM is set to operate (ON) and the hot gas valve HV is closed (OFF). In addition, changeover switch SW ₂ The relay X connected to the movable contact “a” of _Three Normally open contact X _Three The water supply valve WV is connected to -a. Further, the relay X connected to the power source _Four Normally open contact X _Four The compressor CM is connected to -a. And the relay X _Four The excitation and demagnetization control the supply and stop of electricity to each load including the compressor CM.
[0021]
Relay X ₁ Is set to be demagnetized when the ice making thermistor TH detects the deicing completion temperature and to be excited when the thermistor TH detects the ice making completion temperature, whereas the relay X ₂ , X _Three Is set to be excited when the ice making thermistor TH detects the deicing completion temperature and demagnetized when the thermistor TH detects the ice making completion temperature. However, relay X ₂ With regard to the above, when the ice making thermistor TH detects the upper limit temperature at the time of abnormality in the stopped state, it is excited, and when the lower limit temperature (ice making completion temperature) is detected by the ice making thermistor TH, it is demagnetized. The relay X _Four Is the ice storage switch SW ₁ Is demagnetized when the switch is in the detection state (ON), and the switch SW ₁ Is set to be excited when becomes non-detection state (OFF). Furthermore, the relay X ₁ Is the ice storage switch SW ₁ Is set to be demagnetized when it is in the detection state (ON), for example, when the water tray 22 is in the deicing position, the ice storage switch SW ₁ The microcomputer PC is configured to immediately shift to the stop state when the state becomes the detection state (ON). That is, in this stop state, the relay X _Four Demagnetization (compressor CM OFF), relay X ₁ Demagnetization (rotation to the reverse side of the actuator motor AM), relay X ₂ Demagnetization (the hot gas valve HV can be energized), relay X _Three Is set to be demagnetized (water supply valve WV is OFF).
[0022]
The microcomputer PC includes an ice making backup timer that starts from the start of the ice making operation (detection of the deicing completion temperature of the ice making thermistor TH) and the deicing that starts from the start of the ice removing operation (detection of the ice making completion temperature of the ice making thermistor TH). When a backup timer (not shown) is connected and the ice making operation or deicing operation is not completed even after the set time of both timers has elapsed (the switch SW ₂ When the ice making thermistor TH does not detect the ice making completion temperature or the deicing completion temperature), it is set to shift to the stop state as an interlock.
[0023]
[Effect of the embodiment]
Next, the operation of the operation method of the automatic ice making machine according to the embodiment will be described with reference to the timing charts of FIGS.
[0024]
(Initial operation and ice making operation)
When a power switch of an automatic ice making machine (not shown) is turned on, the microcomputer PC is connected to the ice storage switch SW. ₁ If the ice block is not detected (OFF), it is determined that the ice making / deicing operation is possible, and the relay X _Four Is excited. Therefore, relay X _Four Normally-open contact X closed in cooperation with _Four The compressor CM is energized via -a, and the compressor CM is operated (ON). The relay X ₁ Switch is connected to the contact “ab” side (forward rotation side). ₂ And the relay X ₁ Normally-open contact X closed in cooperation with ₁ The actuator motor AM energized via −a is rotated in the forward rotation direction, and the water tray 22 held at the ice making position starts to tilt obliquely downward. Relay X ₁ Normally closed contact X in cooperation with ₁ Since -2b is opened, the pump motor PM is in a stopped state (OFF).
[0025]
When the power switch is ON, the relay X ₂ , X _Three Is held in a demagnetized state, and the relay X ₂ Normally closed contact X ₂ The hot gas valve HV energized via -b is opened (ON), and hot gas is supplied to the evaporator 18. Relay X ₂ Normally closed contact X ₂ Since -a is open, the fan motor FM is not energized, and the motor FM is held in a stopped state (OFF). Relay X _Three Normally open contact X _Three -A is open, the water supply valve WV is not energized, and the water supply valve WV is closed (OFF).
[0026]
When the water tray 22 arrives at the deicing position, the change-over switch SW ₂ Are switched to the “ac” side (reverse side). At this time, since the ice making chamber 14 is heated via the evaporator 18 to which hot gas is supplied, the ice making thermistor TH detects the deicing completion temperature, and therefore the relay X ₁ Is demagnetized and the relay X ₁ Normally closed contacts X ₁ When -1b is closed, the actuator motor AM is rotated in the reverse direction, and the water tray 22 returns toward the ice making position. Relay X ₂ Is normally excited and works with this normally open contact X ₂ -A is closed, the fan motor FM operates (ON), and the relay X ₂ Normally closed contacts X ₂ -B is opened, the hot gas valve HV is closed (OFF), and a refrigerant is supplied to the evaporator 18. Furthermore, relay X _Three Is normally excited and works with this normally open contact X _Three -A is closed, the water supply valve WV is opened (ON), tap water (ice making water) is supplied to the upper surface of the water tray 22 through the water supply pipe 30, and the ice making water passes through the return hole. To the ice making water tank 20. The ice making backup timer is started when the ice making thermistor TH detects the deicing completion temperature.
[0027]
When the water tray 22 arrives at the ice making position, the change-over switch SW ₂ Is switched to the “a-b” side, but at this time, the ice making thermistor TH has not detected the ice making completion temperature. ₁ Normally open contact X ₁ -A is open, the rotation of the actuator motor AM is stopped, and the water tray 22 is held in the ice making position. The water supply valve WV is closed (OFF) after a predetermined time by a water supply timer, and the supply of ice making water is stopped.
[0028]
Furthermore, the changeover switch SW ₂ Is switched to the “ab” side, relay X ₁ Normally closed contact X ₁ -B is applied to the pump motor PM and the motor PM rotates (ON), and the ice making water in the ice making water tank 20 is supplied from each of the fountain holes provided in the water tray 22 to each ice making chamber 14a. Injected into the inside. Since the ice making chamber 14a is cooled by the evaporator 18 through which the refrigerant is circulated, the ice making water comes into contact with the wall of the ice making chamber and is cooled, and then flows down from the return hole of the water tray 22 to make the ice making water tank 20. Return to As the ice making water circulates between the ice making water tank 20 and the ice making chamber 14a in this way, the temperature of the ice making water gradually decreases. When the temperature reaches near 0 ° C., the ice making water is formed on the inner wall of the ice making chamber 14a. Some of them begin to freeze. In this way, freezing in each ice making chamber 14a gradually proceeds, and finally a solid square ice mass is generated.
[0029]
(About deicing operation)
When the ice making thermistor TH detects the ice making completion temperature at which a complete ice block is generated in the ice making chamber 14a of the ice making chamber 14, the relay X ₂ , X _Three Is demagnetized and relay X ₂ Normally open contact X in cooperation with ₂ -A is released, fan motor FM stops (OFF) and normally closed contact X ₂ By closing -b, the hot gas valve HV is opened (ON) and hot gas is supplied to the evaporator 18. Relay X ₁ Is excited and the relay X ₁ Normally closed contacts X ₁ When -2b is opened, the pump motor PM stops (OFF) and the supply of ice-making water to the ice making chamber 14a is stopped. Furthermore, relay X ₁ Normally open contact X closed in cooperation with ₁ The actuator motor AM starts to rotate in the forward direction via -a, and the water dish 22 starts to tilt obliquely downward. Then, when the water tray 22 arrives at the deicing position, the selector switch SW ₂ Are switched to the “ac” side. At this time, the relay X ₁ Normally closed contact X ₁ Since -1b is open, the actuator motor AM stops rotating (OFF), and the water tray 22 is stopped and held at the deicing position.
[0030]
When the ice making thermistor TH detects the ice making completion temperature, the ice making backup timer is stopped and the deicing backup timer is started. If the time for setting the ice making backup timer is completed before the ice making thermistor TH detects the ice making completion temperature, the microcomputer PC determines that an abnormal situation has occurred and sets the automatic ice making machine as an interlock. Transition to the stopped state. The changeover switch SW ₂ The microcomputer PC determines that an abnormal situation has occurred even when the set time of the deicing backup timer has been completed without switching the contact of “a-c” side, and automatic ice making as an interlock is performed. Move the machine to the stop state.
[0031]
The changeover switch SW ₂ Is switched to the “ac” side, the relay X _Three Is normally excited and the normally open contact in cooperation with this is X _Three When -a is closed, the water supply valve WV is opened (ON) (see FIG. 4), and tap water (washing water) is supplied to the upper surface of the inclined water dish 22 through the water supply pipe 30. . With this washing water, the ice adhering to the upper surface of the water dish is washed away, and the ice closing the fountain hole is also melted, and the water supply valve WV is closed (OFF) after a predetermined time by the ice melting timer.
[0032]
The ice making chamber 14 is rapidly heated by the hot gas supplied to the evaporator 18 by opening (ON) the hot gas valve HV. For this reason, the connection between each ice making chamber 14a and the ice block is released, and the ice block falls due to its own weight. Then, it slides down the upper surface of the water tray 22 at the deicing position and is guided and released into the ice storage chamber 32 located below it. Due to the fall of the ice block, the negative temperature load in the ice making chamber 14 is released, and the ice making chamber 14 rises in temperature due to the flow of hot gas in the evaporator 18. When the ice making thermistor TH detects this temperature rise (deicing completion temperature), the relay X ₁ Is demagnetized and the relay X ₁ Normally closed contacts X ₁ By closing -1b, the actuator motor AM starts to rotate in the reverse direction. When the ice making thermistor TH detects the deicing completion temperature, the ice making backup timer is stopped and the ice making backup timer is started. However, if the set time of the deicing backup timer is completed before the ice making thermistor TH detects the deicing completion temperature, the microcomputer PC determines that an abnormal situation has occurred, and the automatic ice making as an interlock is performed. Move the machine to the stop state.
[0033]
The relay X ₂ Is normally excited and works with this normally open contact X ₂ -A is closed and the fan motor FM is operated (ON), and the normally closed contact X ₂ -B is opened, the hot gas valve HV is closed (OFF), and a refrigerant is supplied to the evaporator 18. Furthermore, relay X _Three Is normally excited and works with this normally open contact X _Three -A is closed, the water supply valve WV is opened (ON), and ice making water is supplied to the ice making water tank 20. Then, the water tray 22 returns to the ice making position, and the changeover switch SW ₂ The above-mentioned ice making operation is restarted by switching the contact point to “ab” side. Changeover switch SW ₂ If the time of the set time of the ice making backup timer is completed without switching the contact of “a-b” side, the microcomputer PC determines that an abnormal situation has occurred, and sets the automatic ice making machine as an interlock. Transition to the stopped state.
[0034]
(About operation when stopped)
The ice storage switch SW indicates that a predetermined amount of ice blocks have been stored in the ice storage chamber 32 by repeating the ice making operation and the deicing operation described above. ₁ Is detected, the microcomputer PC stops the ice making / deicing operation and moves the relay X to the stop state in which the ice block is not manufactured. _Four Is demagnetized. As a result, relay X _Four Normally open contact X in cooperation with _Four -A is opened, and the supply of electricity to each load such as the compressor CM is stopped. That is, during the deicing operation, the ice storage switch SW ₁ Is in the detection state (ON), the water tray 22 is moved to the stop state while being held at the deicing position, and the ice storage switch SW is operated during the ice making operation. ₁ Is in the detection state (ON), the water tray 22 shifts to the stop state while being held at the ice making position.
[0035]
As described above, in the stopped state, the relay X of the control circuit _Four Is demagnetized so that electricity is not supplied to each load such as the compressor CM and the fan motor FM. _Four Normally open contact X _Four An abnormal situation may occur in which -a is welded for some reason and the contact is not opened. In this case, in the stop state, the relay X ₁ Is demagnetized, for example, the ice storage switch SW during the deicing operation ₁ Is in the detection state (ON), the welded relay X _Four Normally open contact X _Four -A is energized to the actuator motor AM through the relay X as shown in FIG. ₁ Normally closed contacts X ₁ The actuator motor AM starts to rotate in the reverse direction via -1b, and the water tray 22 is moved to the ice making position.
[0036]
In the stop state, the relay X ₂ Is demagnetized and the hot gas valve HV can be energized, so the welded relay X _Four Normally open contact X _Four When the compressor CM and the hot gas valve HV are energized via -a, the compressor CM is operated and the hot gas valve HV is opened, and hot gas is supplied to the evaporator 18 to supply the ice making chamber 14. Will be heated. If this state continues for a long time, as described above, the resin holder and the resin spacer 12 that are in contact with the ice making chamber 14 are deformed. Therefore, in the embodiment, even in the stopped state, the relay X depends on the detected temperature of the ice thermistor TH. ₂ Excitation and demagnetization are controlled to prevent excessive heating and cooling of the ice making chamber 14.
[0037]
That is, the ice making chamber 14 is heated by the supply of hot gas to the evaporator 18, the temperature rises above the deicing completion temperature as shown in FIG. 5, and the ice making thermistor TH is preset. When the upper limit temperature at the time of abnormality is detected, the relay X ₂ Is normally excited contact X that is excited ₂ -A is closed and the fan motor FM is operated (ON), and the normally closed contact X ₂ -B is opened, the hot gas valve HV is closed (OFF), and a refrigerant is supplied to the evaporator 18. Thereby, the ice making chamber 14 is cooled. When the ice making thermistor TH detects that the temperature of the ice making chamber 14, which is lowered by the supply of the refrigerant to the evaporator 18, has reached a preset lower limit temperature (ice making completion temperature) at the time of abnormality, Relay X ₂ Is demagnetized and relay X ₂ Normally open contact X in cooperation with ₂ -A is released, fan motor FM is stopped (OFF) and normally closed contact X ₂ By closing -b, the hot gas valve HV is opened (ON) and hot gas is supplied to the evaporator 18. Thereby, the ice making chamber 14 is heated.
[0038]
As described above, by repeating the supply of the hot gas to the evaporator 18 and the supply of the refrigerant, the ice making chamber 14 is maintained between the upper limit temperature and the lower limit temperature, and the ice making chamber 14 is excessively heated. Or cooling is prevented. Therefore, it is possible to prevent the resin holder for attaching the ice making thermistor TH to the ice making chamber 14 and the resin spacer 12 from being deformed, and to prevent a large amount of frost from adhering to the expansion valve 38.
[0039]
The ice storage in the ice storage chamber 32 is consumed and the storage level decreases, and the ice storage switch SW ₁ Is in the non-detection state (OFF), the microcomputer PC controls the operation to shift from the stop state to the ice making / deicing operation. In this case, since the resin holder and the resin spacer 12 are not deformed due to excessive heating of the ice making chamber 14 in the stopped state, or a large amount of frost is not formed on the expansion valve 38 due to excessive cooling. Thus, the subsequent ice making / deicing operation can be performed without any trouble.
[0040]
It should be noted that even when the interlocking state is shifted to the stop state due to an abnormality determined by the ice making backup timer or the deicing backup timer, the same operation is performed to prevent the ice making chamber 14 from being excessively heated or cooled. Therefore, it does not develop into a serious abnormality until the operator notices the abnormality.
[0041]
In the control circuit of the above-described embodiment, the relay X which is demagnetized in the stopped state ₂ Normally closed contact X ₂ In the above description, the hot gas valve HV is configured to be energized via -b. ₂ Even if the fan motor FM is set in a state in which the energization is possible via -b, the operation is controlled as in the embodiment so that the refrigerant is continuously supplied to the evaporator and the ice making chamber becomes excessive. Can be prevented from being cooled.
[0042]
In the embodiment, the closed cell type automatic ice making machine that closes the ice making chamber with a water tray has been described. However, the open cell method in which ice making water is directly injected into the ice making chamber without going through the water plate, or the ice making plate. The operation method of the present invention can be suitably applied to an automatic ice making machine adopting any other ice making method, such as a flow down type in which ice making water is supplied to the surface of the (ice making part) to form ice blocks. .
[0043]
【The invention's effect】
As described above, according to the operation method of the automatic ice maker according to the present invention, when the electric power is supplied to each load in the stopped state due to the abnormality of the control circuit, the supply of the refrigerant to the evaporator is performed. Since the supply of hot gas is repeated based on the temperature detected by the temperature detecting means, excessive heating and cooling of the ice making unit can be prevented. That is, it is possible to prevent a situation in which the resin component attached to the ice making unit is deformed by heating and the normal operation cannot be performed when the ice making / deicing operation is restored.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an ice making mechanism of an automatic ice making machine in which an operation method according to a preferred embodiment of the present invention is implemented.
FIG. 2 is a schematic configuration diagram showing a refrigeration system of the automatic ice making machine according to the embodiment.
FIG. 3 is a control circuit diagram of the automatic ice maker according to the embodiment.
FIG. 4 is a timing chart during an ice making / deicing operation of the automatic ice making machine according to the example.
FIG. 5 is an operation timing chart when the automatic ice making machine according to the embodiment is stopped.
[Explanation of symbols]
14 ice making room (ice making part), 16 refrigeration system, 18 evaporator, 36 condenser
TH ice thermistor (temperature detection means), HV hot gas valve
FM fan motor

Claims (2)

During the ice making operation, an ice block is generated by supplying a refrigerant from the refrigeration system (16) to the evaporator (18) disposed in the ice making unit (14), and after the ice making is completed, the ice removing operation is performed. In an automatic ice maker configured to deice ice blocks by supplying hot gas to the evaporator (18) and heating the ice making section (14),
In the stop state where the ice making-deicing operation is stopped, when electricity is supplied to each load due to an abnormality in the control circuit, the temperature detection means (TH) for detecting the temperature of the ice making part (14) is detected. Based on this, the method of operating the automatic ice making machine is characterized in that the supply of the refrigerant and the supply of hot gas to the evaporator (18) are repeated. In the stopped state, when the temperature detecting means (TH) detects the upper limit temperature at the time of abnormality, the hot gas valve (HV) of the refrigeration system (16) is closed and refrigerant is supplied to the evaporator (18). And operating a fan motor (FM) that air-cools the condenser (36) of the refrigeration system (16),
When the temperature detecting means (TH) detects a lower limit temperature at the time of abnormality, the hot gas valve (HV) is opened to supply hot gas to the evaporator (18), and the fan motor (FM) The method of operating an automatic ice maker according to claim 1, wherein the operation is stopped.

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