JPS6157988B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ice-making machine that uses a circulation pump to circulate ice-making water stored in a tank in an ice-making member equipped with a refrigeration system to freeze the ice-making member, and in particular, to reliably detect a water outage. The present invention provides a method and device for detecting water outage.

An embodiment of the present invention will be described below based on the drawings. FIG. 1 shows one type of ice maker implementing the present invention, and 1 is an ice maker main body formed of a heat insulating wall;
An ice-making member 3 to which a refrigeration system evaporation pipe 2 is connected is installed at an angle, and below the ice-making member 3 there is a water storage tank 6 for storing ice-making water supplied from a water supply pipe 5 connected to a water source via a water supply valve 4; The tank 6
A circulating pump 7 is installed inside the ice making system to form a running water circulation type ice making system, and an ice storage chamber 8 is located above the ice storage chamber 8 in front of the lower edge of the ice making member 3 to receive ice cubes after deicing. A heater device 9 for cutting ice sheets is arranged to cut ice cubes into blocks of size. In addition, the machine room 10 includes an electric compressor 11, a condenser 12, and a condenser 12.
An air cooling fan 13 is provided.

Next, the electric circuit of the present invention will be explained based on FIG. 14 is a temperature detection device that detects the temperature of the ice making member 3; 15 is a first determination device that compares the set value by the first divided resistors 16 and 17 with the detected value of the temperature detection device 14, and determines the detected value. When the temperature reaches a predetermined low temperature, an output signal "1" is generated. Reference numeral 18 denotes a second determination device that compares the set value by the second dividing resistors 19 and 20 with the detected value of the temperature detection device 14, and when the detected value reaches a predetermined low temperature lower than the predetermined low temperature. Generates an output signal “1”. 21 is a first AND circuit which receives the output signal of the first determination device 15 and the clock; 22 is a counter circuit 23;
A timer circuit constituted by a comparator 24 and a memory circuit 25, in which the clock output from the first AND circuit 21 is counted by a counter circuit 23, and the count content exceeds a set value of the memory circuit 25. When the comparator 24 outputs a signal “1”
occurs. 26 is a reset terminal of the counter circuit 23, which receives the output signal "0" of the first determination device 15.
will be reset. A first inverter 27 27 inverts the output signal of the comparator 24 is a second AND circuit which receives the output signal of the inverter 27 and the output signal of the second determination device 18, and outputs the output from R-. It is used as a set input for the S flip-flop 29. 30 is a second inverter that inverts the output signal of the first determination device 15;
The output is used as the reset input of the flip-flop 29. A first relay 32 is connected to the output side of a third determination device 31 consisting of a second AND circuit 28 and a flip-flop 29. 32a is a normally closed contact of the first relay 32; 33, which is connected via the contact 32a, is an ice-making termination thermostat that detects a predetermined decrease in the evaporation temperature and ends the ice-making operation; 34 is a second The relay 34b is a self-holding contact of the second relay 34, and 35 is a deicing termination device that detects a predetermined temperature rise of the ice making member 3 that increases by circulating hot gas in the refrigeration system and terminates the deicing operation. A thermostat 34a is a normally closed contact of the second relay 34, which connects the circulation pump 7 and the fan 13. 34b is the second relay 3
The hot gas valve 36 and the water supply valve 4 are connected by the normally open contact point 4. 11 is the electric compressor. On the other hand, 32b is a normally open contact of the first relay 32, and the water cutoff alarm lamp 38 is connected to the secondary side of the transformer 37 via the contact 32b.

Next, the operation of the present invention will be explained from the start of ice making. First, the timer circuit 22 is connected to the first determination device 1.
Since the output signal "0" is generated from the counter circuit 23, the counter circuit 23 is in a reset state and therefore does not operate. Further, since the output signal "0" of the first determining device 15 is inputted to the reset input terminal of the flip-flop 29 via the second inverter 30, the output signal "0" is generated from the output terminal of the flip-flop 29. Therefore, the first relay 32 is de-energized, its contact is located at the normally closed contact 32a, the electric compressor 11 is operating, and the ice-making termination thermostat 33 is open, so the second relay 34 is When de-energized, the circulation pump 7 and fan 13 operate via the normally closed contact 34a to start ice-making operation. When the temperature detection device 14 detects a predetermined temperature drop of the ice making member 3, the first determination device 15
generates an output signal "1". Then, the reset of the counter circuit 23 is released, and since the lock and the output of the first determining device 15 are ANDed, the counter circuit 23 starts counting the clock. On the other hand, "0" is input to the reset input terminal of the flip-flop 29, and "0" is input to the set input terminal because the second AND circuit 28 cannot perform an AND operation. Therefore, the output of the flip-flop 29 remains at the previous state of "0", the first relay 32 continues to be de-energized, and the ice-making operation continues.

When the time-up signal is generated from the comparator 24 of the timer circuit 22, if the temperature detection device does not detect a predetermined temperature drop lower than the predetermined temperature drop of the ice-making member 3, the second AND circuit 28 outputs an AND signal. Therefore, "0" is input to the set input terminal of flip-flop 29. On the other hand, since "0" is input to the reset input terminal of the flip-flop 29, the output of the flip-flop 29 continues to maintain the previous state of "0" output, and the first relay 32 continues to be de-energized to operate the ice making operation. Continue further.

Furthermore, after the time-up signal is generated, the temperature detection device 1
4 detects a predetermined temperature drop that is lower than the predetermined temperature drop of the ice making member 3, and even if the output signal "1" is generated from the second determination device 18, the second AND circuit 28 cannot take the AND. The output "0" of the flip-flop 29 remains unchanged, the first relay 32 is de-energized, and the ice-making operation continues.

When the ice-making termination thermostat 33 finally operates, the second relay 34 is energized, switching its contact from the normally closed contact 34a to the normally open contact 34b, stopping the circulation pump 7 and fan 13, and ending the ice-making operation. The electric compressor 1 operates the gas valve 36 and the water supply valve 4 and continues to operate.
From 1 onwards, the condenser 12 is bypassed and the hot gas of the refrigeration system is passed through the evaporation pipe 2 to start deicing operation of ice sheets frozen on the ice making member 3. When the ice removal operation is started, the temperature of the ice making member 3 rises, and the ice sheet finally separates from the ice making member 3 and falls onto the ice sheet cutting heater device 9. At this time, when the deicing thermostat 35 detects the increased temperature of the ice making member 3, its contacts are opened, the excitation of the second relay 34 is released, and the contacts are changed from the normally open contact 34b to the normally closed contact 34a.
to start the next cycle of ice-making operation.
Note that as the temperature of the ice-making member 3 rises during the deicing operation, the output of the second determining device 18 and then the first determining device 15 changes from "1" to "0"; The signal "1" is never generated. When the output of the first determining device 15 changes to "0", the timer circuit 22 is reset and ready for the next cycle.

The above describes one normal cycle of circuit operation without water outage. That is, when water is being supplied normally to the water storage tank 6, when the water in the water storage tank 6 is circulated to the ice making member 3 during the ice making operation, heat exchange between the water and the ice making member 3 occurs, so that the ice making member The gradient of the temperature drop in No. 3 is a gentle curve as shown by the solid line in FIG. Therefore, in the present invention, if the temperature of the ice making member 3 does not drop to the second lower temperature when the time-up signal is generated, it is determined that the water supply operation is being performed normally, and one cycle of the ice making operation and ice removal operation is performed as described above. will be carried out.

However, if water is not normally supplied to the water storage tank 6, for example in the case of a water outage, water will not be circulated to the ice making member 3 during the ice making operation, so the gradient of the temperature drop in the ice making member 3 will be as shown in Figure 3. It becomes steeper as shown by the dotted line. Therefore, in the present invention, if the temperature of the ice making member 3 falls to the second lower temperature before the time-up signal is generated, it is determined that the water supply operation is not being performed normally and a water cutoff signal is generated. Explain circuit operation. When the ice-making operation is started as described above, the temperature detection device 14 first detects a predetermined temperature drop of the ice-making member 3, and the first determination device 15 generates an output signal "1". Then, the reset of the counter circuit 23 is released, the timer circuit 22 operates, and the counter circuit 23 starts counting the clock. At this time, the output of the flip-flop 29 is maintained at "0" as described above, so the first relay 32 is de-energized and the ice-making operation continues.

Therefore, the temperature of the ice making member 3 continues to drop rapidly.
Since the temperature detection device 14 detects a predetermined temperature drop lower than the predetermined temperature drop before the time-up signal is generated, the second determination device 18 generates an output signal "1". Then, the second AND circuit 28 performs an AND with the time-up signal, and inputs "1" to the set input terminal of the flip-flop 29. At this time, since "0" is input to the reset input terminal of flip-flop 29, flip-flop 29 generates an output signal "1". Therefore, the first
Relay 32 is energized and its contacts are normally closed contacts 32
Transformer 37 by switching from a to normally open contact 32b
Power is supplied to the secondary side of the machine, the water outage warning lamp 38 is turned on to notify that there is a water outage, and the electric compressor 11, circulation pump 7, and fan 13 are made inoperable to stop the ice making operation and protect the machine. do. In addition,
As the temperature of the ice making member 3 rises due to the stoppage of the ice making operation, the output of the second determining device 18 and then the first determining device 15 changes from "1" to "0", but the output signal of the flip-flop 29 changes from "1" to "0". maintains the signal "1", which indicates a water cutoff, so it does not restart operation even though the water is cut off. When the water cutoff is lifted, water is supplied to the water storage tank 6 by operating only the water supply valve 4, and then by resetting all circuits with a reset switch (not shown), operation can be started from ice making operation. The details of the notification by the water cutoff signal and the recovery operation after the operation is stopped are omitted here because they are outside the scope of the present invention. In addition, in the embodiment, the temperature detection device 1
4 directly detects the temperature of the ice making member 3, but the temperature of the evaporation pipe 2 or suction side piping may also be detected.

As described above, the temperature of the ice-making member reaches a predetermined reduced temperature lower than the predetermined reduced temperature before a predetermined time elapses after the ice-making operation is started and the temperature of the ice-making member reaches the predetermined reduced temperature. The water cutoff detection method determines that the water cutoff has occurred when the temperature reaches the temperature limit, and also includes a temperature detection device that detects the temperature of the ice making member, and a temperature detection device that determines whether or not the first temperature drop has been detected and generates each signal. a second determining device that determines whether or not the temperature detecting device detects a second decreased temperature lower than the first decreased temperature and generates each signal; a timer that starts based on a signal from the first determining device when a first temperature drop is detected; and a timer that starts based on a signal from the first determining device when a first temperature drop is detected; This water cutoff detection device is equipped with a third determination device that generates a water cutoff signal based on the signal and the signal from the timer before the time-up signal is generated when a signal indicating that a drop in temperature is detected is generated. It is possible to reliably detect a normal state and a water outage state based on the relationship between the
That is, the embodiment has the advantage that it is possible to turn on the notification lamp or stop the ice-making operation at an early stage.

In addition, it is possible to judge whether the water is normal or not, within the range where the temperature change state during normal conditions and the temperature change state during water outage clearly appear, and under any conditions of ambient temperature or water temperature during water supply. It has the advantage of being extremely reliable and can accurately determine whether the water is normal or not.

Furthermore, the present invention is not limited to the so-called plate type ice maker as in the embodiment, but can be widely implemented in various other types of ice maker.

[Brief explanation of the drawing]

FIG. 1 is an internal view of an ice making machine in which the present invention can be implemented, FIG. 2 is an electric circuit diagram of the present invention, and FIG. 3 is a diagram showing the relationship between time and temperature of the ice making member. 3...Ice making member, 14...Temperature detection device, 15
...first determination device, 18...second determination device,
22 ...Timer circuit, 31 ...Third determination device.

Claims (1)

[Scope of Claims] 1. In an ice-making machine that circulates ice-making water stored in a tank in an ice-making member equipped with a refrigeration system using a circulation pump to freeze the ice-making member, an ice-making operation is started. Water cutoff when the temperature of the ice making member or suction side piping reaches a predetermined reduced temperature that is lower than the predetermined reduced temperature before a predetermined time has elapsed after the temperature of the ice making member or suction side piping reached the predetermined reduced temperature. A method for detecting a water outage in an ice maker, characterized by determining that 2. In an ice making machine that uses a circulation pump to circulate ice making water stored in a tank in an ice making member equipped with a refrigeration system to freeze the ice making member, the temperature at which the temperature of the ice making member or suction side piping is detected. a detection device; a first determination device that determines whether or not the detection device has detected a first temperature drop and generates each signal;
a second determining device that generates each signal by determining whether or not a second decreased temperature lower than the first decreased temperature is detected; a timer that starts based on a signal from a determination device; and a timer that starts when the temperature detection device detects a second temperature drop is generated from the second determination device before the time-up signal of the timer is generated; A water cutoff detection device for an ice maker, comprising a third determination device that generates a water cutoff signal based on the signal and a signal from the timer before the time-up signal is generated.