JPH0812027B2 - Water outage detection device for downflow type ice machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a downflow type ice making machine that circulates hot gas in an evaporator pipe provided in a cooler to perform an ice removing operation of frozen ice in the cooler. In particular, it relates to a water cutoff detection device.

(B) Conventional technology The water cutoff detection device disclosed in Japanese Utility Model Publication No. Sho 59-38688 discloses a compressor in which the contact is turned off when the water supply to the ice making tank is not completed within a set time. It is equipped with a timer for detecting water cutoff.

(C) Problems to be Solved by the Invention Such a water break detection device of the related art requires the provision of a water level detection device in addition to the water cut detection dedicated timer, which makes the device expensive and also serves as a water level detection device. Since the float system is adopted, there is a problem that it malfunctions due to the ripple phenomenon of the ice making water tank.

(D) Means for Solving the Problems The present invention relates to a water shutoff detection device for a downflow type ice making machine, in which hot gas is circulated through an evaporation pipe provided in a cooler, and ice is frozen in the cooler. An ice freezing / water breakage detection sensor provided in the evaporation pipe, and an ice removal due to a predetermined rise temperature of the cooler due to the ice freezing operation, and a water storage tank in response to the output of the ice freezing / water break detection sensor. A detection circuit for detecting water interruption due to a predetermined lowered temperature of the cooler during the ice making operation performed by circulating the ice making water supplied to the cooler to the cooler and circulating the low temperature refrigerant to the evaporation pipe. A water cutoff detection device for a downflow type ice making machine, which is provided with an informing unit that operates based on the water cutoff signal to notify the water cutoff.

(E) Action The present invention provides an ice release detection sensor (23) for detecting ice detachment due to a predetermined temperature rise of a cooler due to ice removal operation.
When a predetermined lowering temperature of the cooler (1) is detected during ice making, the water cutoff detection circuit outputs a water cutoff signal, whereby the water cutoff alarm LED (135), which is a notification means, blinks to notify the water cutoff.

(F) Embodiments Embodiments of the present invention will be described below with reference to the drawings. First, the structure of the downflow type ice making machine of the present invention will be described with reference to FIG. 2 and FIG. 3. The cooler (1) for freezing the ice making water is a pair of cooling devices which are arranged at a substantially vertical interval. The cooling plates (2) and (3) and the cooling plates (2) and (3), which are arranged as a part of the cooling plates (2) and (3) with vertical and horizontal intervals.
A large number of circular ice-making buttons (4) and (5) exposed so as to be substantially flush with the surface of (3) and the back surfaces of the cooling plates (2) and (3) are arranged in a meandering shape to cool one side. Ice making button (4) on the plate (2) side and ice making button (5) on the other cooling plate (3) side
It is constituted by an evaporation pipe (6) sandwiched by.

Also, an electric compressor (7), a condenser (9) forcibly cooled by an air blower (8), and an expansion valve (1) as a pressure reducing device.
0) and the evaporation pipe (6) are connected in an annular shape to form a refrigerant circuit, which is a hot gas bypass pipe (11) for circulating hot gas in the evaporation pipe (6) and a hot gas solenoid valve (12). Is equipped with.

Next, explaining the water system, (13) sprinkles tap water supplied from a water supply pipe (15) to which a water supply solenoid valve (14) is connected to the upper back surfaces of the cooling plates (2) and (3). Sprinkler for water supply and ice removal, (16) is a sprinkler for ice making that sprinkles water on the upper surface of the cooling plates (2) and (3), and is installed in the water storage tank (18) via the water conduit (17). Connected to the circulating pump (19). (20) is tap water that is sprinkled from the water supply / ice separation sprinkler (13) and unfrozen water that is sprinkled from the ice making sprinkler (16) and that does not freeze, and is guided to the water storage tank (18) It is a gutter and is arranged below the cooler (1). (21) is an overflow pipe connected to the upper part of the water storage tank (18).

In addition, (22) is made into the ice making button (4) so that the temperature of the water flowing on the surface of the frozen ice is sensed.
By arranging them facing each other with a certain space in front of
The ice-making detection sensor (23) for detecting the growth of a predetermined ice in the cooler (1) is arranged so as to detect the outlet temperature of the evaporation pipe (6), so that the ice from the cooler (1) is detected. A sensor for deicing and water interruption detection that detects detachment and water interruption, (24) is arranged so as to detect the outlet temperature of the condenser (9) that is dependent on the ambient temperature, and thus indirectly detects the ambient temperature. The ambient temperature detection sensor detects abnormally high temperature of the condenser (9) due to switching of water supply time and clogging of the filter (25) arranged in front of the condenser (9).

Next, the electric circuit of the present invention will be described with reference to FIG.
(26) is a power transformer, (27) is a rectifier circuit, (28) is a smoothing capacitor, (29) is a capacitor (30) and a resistor (31).
An inverter (32) having an input connected to a connection point thereof, an inverter (33) receiving an output of the inverter (32), and a diode (34 connected between an output of the inverter (33) and an input of the inverter (32). ) And a resistor (35), the self-holding circuit (36) is connected through the dividing resistors (37) and (38), and the diode (39) is the forward direction to the inverter (32). Similarly, the self-holding circuit (87), which will be described later, is also connected through the split resistors (37) and (38).
A diode whose forward direction is to the inverter (83), (40) is a transistor whose base is connected to the connection point of the dividing resistors (37) and (38), and (41) is a transistor (4
When the power supply voltage is applied to start when (0) is turned on, and at the same time, "H" is output to the output terminal (41A), the water supply time is based on the temperature detected by the ambient temperature detection sensor (24). It can be switched to either "long" or "short". That is, when one analog switch (42) is ON, it oscillates in a short cycle conditioned by the variable resistor (43) and capacitor (44), and when the other analog switch (45) is ON. Oscillates in a long cycle conditioned by the variable resistor (46) and capacitor (44), and outputs a predetermined time (for example, 30 seconds when short, 5 minutes when long) by counting a predetermined number of oscillation pulses. Switch the voltage of the terminal (41A) from "H" to "L". (47)
Splits the output of the water supply timer (41) with resistors (48) and (4
Transistor received via 9), (50) is the first relay excited by turning on transistor (47), and (51) is a self whose forward direction is the direction to output terminal (41A) of water supply timer (41). It is a diode for releasing holding.

Next, the configuration of the ice making detection circuit (52) will be described. The negative characteristic thermistor as the ice making detection sensor (22) is connected to one end of a constant current circuit composed of a Zener diode (53), a resistor (54), a variable resistor (55) and a transistor (56). (57) is a buffer circuit for inputting the terminal voltage of the ice making detection sensor (22) to the positive input terminal, (58)
Is a capacitor that forces the output of the buffer circuit (57) to "H" when the power is turned on, and (59) is the buffer circuit (57).
The output of is connected to the negative input terminal through resistors (60) and (61) and to the positive input terminal through resistors (60) and (62), and a capacitor (63) is connected between the positive input terminal and ground. A differential amplifier (64) that connects the output of the differential amplifier (59) to the positive input terminal through the resistor (65) and the output of the buffer circuit (57) through the resistor (60).
A comparator connected to the negative input terminal through (66) connects the output of the comparator (64) to the negative input terminal through a resistor (67) and also applies a bias voltage due to the resistors (68) and (69). A comparator (70) connected to the positive input terminal connects the output of the buffer circuit (57) to the positive input terminal via the resistor (71), and also a variable resistor (72) and a resistor (7).
A comparator in which the bias voltage from 3) is connected to the negative input terminal, and (74) is a diode whose forward direction is from the positive input terminal of the comparator (70) to the output terminal of the comparator (66).

Next, the configuration of the ice release detection circuit (75) will be described. The deicing detection sensor (23) is constructed by using the base and collector of two transistors, and the terminal voltage changes in inverse proportion to the temperature change. (76) connects the connection point voltage of the resistance (77) and the deicing / water breakage detection sensor (23) to the positive input terminal, and the connection point voltage of the resistance (78) and the variable resistance (79) to the negative input terminal. The connected amplifier (80) is a comparator in which the output of the amplifier (76) is connected to the positive input terminal and the bias voltage by the resistors (81) and (82) is connected to the negative input terminal. The output of the comparator (80) is switched from "H" to "L" when the ice / water breakage detection sensor (23) detects a predetermined rise temperature (8 ° C).

Thus, the output of the ice making detection circuit (52), that is, the comparator (7
The output of (0) is an inverter (83) and (84), and a self-holding circuit (diode 85 and a resistor (86) connected between the input of the inverter (83) and the output of the inverter (84). It is connected to the input of the inverter (83) of 87) through the diode (88) and the resistor (89). On the other hand, the output of the ice release detection circuit (75), that is, the output of the comparator (80) is
The inverter (83) of the self-holding circuit (87) is connected through the diode (90) having the forward direction to the output terminal of the comparator (80) and the resistor (91) having a resistance value extremely smaller than that of the resistor (89). ) Is connected to the input. (92) is a transistor that receives the output of the self-holding circuit (87), that is, the output of the inverter (84) via the dividing resistors (93) and (94),
5) is a second relay excited by turning on the transistor (92).

Next, a timer circuit (96) for forcibly ending the ice making and the ice removing when the ice making detection circuit (52) cannot detect the ice making will be described. Reference numeral (97) is a backup timer composed of an oscillation circuit and a counter circuit. The output of the self-holding circuit (87), that is, the output of the inverter (84) is passed through the diode (98) and the resistor (99) to the timer (97). ) Is connected to the reset terminal (97A), and the timer (97) oscillates when "L" is input to the reset terminal (97A) and when "H" is input to the reset terminal (97A). Reset and oscillation stop. Further, the operating time of the timer (97) is variable resistor (100) and capacitor (101) or variable resistor (102).
It depends on the capacitor and the capacitor (101), but this is ON of the analog switch (104) that inputs the output of the timer (97) through the inverter (103) or the analog switch (105) that directly inputs the output of the timer (97). , OFF, and when the analog switch (104) is ON, it oscillates in a long cycle conditioned by the variable resistor (100) and capacitor (101), and the other analog switch (105) is turned ON. When it is present, it oscillates in a short cycle conditioned by the variable resistor (102) and the capacitor (101), and is divided into an ice making time (for example, 40 minutes) and an ice releasing time (for example, 5 minutes). (106) is an inverter (8
Inverter (103) of timer circuit (96) from output of 3)
A diode whose forward direction is an output to the output of the (107) is a forward direction from an output of the inverter (84) of the self-holding circuit (87) to an output of the inverter (103) of the timer circuit (96). It is a diode.

In addition, the circuit for controlling the switching of the water supply time described above has a connection point between the ambient temperature detection sensor (24) and the resistor (108) that use a transistor sensor as in the above-mentioned ice removal and water break detection sensor (23). Connect the voltage to the plus input terminal and connect the resistor (109) and the variable resistor (110) to the minus input terminal and connect the amplifier (111) and the output of the amplifier (111) to the plus input terminal. A comparator (114) having a bias voltage generated by a resistor (112) and a variable resistor (113) connected to its negative input terminal is also provided, and the output of the comparator (114) is passed through an inverter (115) to the one analog switch. (42) and a comparator (11
The output of 4) is directly connected to the other analog switch (45) described above. In the embodiment, when the ambient temperature detection sensor (24) detects a temperature higher than the predetermined temperature (25 ° C.), the output of the comparator (114) is “L”, and when the temperature is below the predetermined temperature, The output of the comparator (114) becomes "H". The diode (116) having the forward direction from the positive input terminal of the comparator (114) to the output of the self-holding circuit (87) acts so as to switch the water supply time only during ice removal. .

Next, a high temperature detection circuit for detecting clogging of the filter (25) and notifying the clogging will be described. The sensor is also used by the ambient temperature detection sensor (24) for controlling the switching of the water supply time, the output of the amplifier (111) is connected to the negative input terminal, and the bias voltage by the resistors (117) and (118) is added to the positive input terminal. A comparator (119) connected to the resistor (120) and one output of the comparator (119), and a resistor (120),
An AND circuit (127) having the output of the oscillation circuit (126) composed of (121), (122) and (123), the capacitor (124) and the operational amplifier (125) as the other input, and the AND circuit (127). 127) and a high temperature alarm LED (129) as a notification means that blinks in synchronization with ON / OFF of the transistor (128). In the embodiment, the ambient temperature detection sensor is used. When (24) detects a predetermined temperature (63 ° C.) or higher, the output of the comparator (119) becomes “H”.

Further, a water cutoff detection circuit for detecting water cutoff and notifying it will be described. The sensor is a sensor (2
And a comparator (132) in which the output of the amplifier (76) is connected to the positive input terminal and the bias voltage by the resistor (130) and the variable resistor (131) is connected to the negative input terminal, and the comparator (132). The output of (132) is one input,
An AND circuit (133) having the output of the oscillation circuit (126) as the other input, a transistor (134) for receiving the output of the AND circuit (133), and ON / OF of the transistor (134).
Water outage alarm LED (13
5), in the embodiment, the output of the comparator (132) becomes "H" when the ice separation detection sensor (23) detects a predetermined lowered temperature (-25 ° C).

On the other hand, the electric compressor (7) is connected to the AC power source, the water supply solenoid valve (14) is connected via the normally open contact (50A) of the first relay (50), and the second relay ( 9
5) The hot gas solenoid valve (12) is connected via the normally open contact (95A), and the parallel circuit of the circulation pump (19) and the blower (8) is connected via the normally closed contact (95B). Has been done.

Next, the operation will be described based on the above configuration. First, when the power is turned on, the “H” voltage is applied to the input of the inverter (32) with the time constant of the capacitor (30) and the resistor (31), so the output of the inverter (33) becomes “H” and the diode (34 ) And the positive feedback of the resistor (35) causes the self-holding circuit (29) to be self-held to ON. Then, the diode (3
Since the base voltage of the transistor (40) is pulled to "L" by 6), the transistor (40) is turned on, the power supply voltage is applied to the water supply timer (41), the timer (41) is started, and at the same time, the output terminal ( 41A) outputs "H".
As a result, the transistor (47) is turned on, the first relay (50) is excited, the normally open contact (50A) is closed, and the water supply solenoid valve (14) is opened to start the water supply operation.

The water supply time is controlled to be switched between the two levels of "long" and "short" as described above based on the temperature detected by the ambient temperature detection sensor (24). In any case, through the water supply pipe (15) the sprinkler (13)
The tap water sprinkled from the water flows down the back surfaces of the cooling plates (2) and (3), and is dropped and collected from the water inlet (1A) at the lower end of the cooler (1) to the water receiving trough (20) and the water storage tank (18). Will be supplied with water.

Then, after a lapse of a predetermined water supply time, the voltage of the output terminal (41A) of the water supply timer (41) is switched from "H" to "L", the transistor (47) is turned off, and the first relay (5) is turned on.
The excitation of (0) is released, the normally open contact (50A) is opened, the water supply solenoid valve (14) is closed, and the water supply operation is completed. Further, the self-holding circuit (29) is turned off to pull the input of the inverter (32) to “L” via the diode (51), and the anode of the diode (36) is set to “H”, so that the transistor ( 40) is turned off and the water supply timer (4
1) is reset to the initial state.

On the other hand, if the ice removal detection sensor (23) detects a temperature equal to or higher than the predetermined temperature when the power is turned on, it starts from the ice making operation at the same time as the start of the water supply described above, and if it detects a temperature lower than the predetermined temperature, it supplies the water. Simultaneously with the start, the ice-breaking operation starts.

That is, when the power is turned on, the output of the buffer circuit (57) is forcibly set to "H" by the capacitor (58). The voltage of the positive input terminal of the differential amplifier (59) that inputs this voltage is
Since the time constant of the resistor (62) and capacitor (63) increases, the voltage at the negative input terminal rises quickly, the output voltage of the differential amplifier (59) decreases, and this voltage is input to the positive input terminal. At the same time, the output of the comparator (64) that inputs the output voltage of the buffer circuit (57) to the negative input terminal becomes “L”, and the voltage of the negative input terminal of the comparator (66) that inputs this becomes the resistance (68) and It becomes lower than the bias voltage by (69) and the output of the comparator (66) becomes "H".
This reverse biases the diode (74),
The comparator (70) receives the output of the buffer circuit (57),
The voltage of the positive input terminal is variable resistance (72) and resistance (73)
The output voltage of the comparator (70) becomes "H" because the voltage becomes higher than the bias voltage due to the output voltage, and this voltage is input to the self-holding circuit (87) via the diode (88) and the resistor (89).

At this time, if the deicing / water breakage detection sensor (23) detects a temperature higher than a predetermined temperature due to the relationship of the resistance (91) << the resistance (89), the terminal voltage of the sensor (23) is low, and this result Since the output voltage of the amplifier (76) also drops, the voltage of the positive input terminal of the comparator (80) becomes lower than the bias voltage of the resistors (81) and (82), and the output of the comparator (80) becomes "L". "
Then, the input of the inverter (83) of the self-holding circuit (87) is pulled to "L" through the resistor (91) and the diode (90), and the self-holding circuit (87) is turned off. That is, the output of the inverter (83) becomes "H", the output of the inverter (84) becomes "L", the transistor (92) does not turn on, and the second
The relay (95) is not energized. Therefore, the second relay (9
The circulation pump (19) and the blower (8) operate via the normally closed contact (95B) of 5), and the electric compressor (7) is activated by turning on the power.
Starts the ice making operation.

On the other hand, when the ice removal / water breakage detection sensor (23) detects a temperature lower than the predetermined temperature, the above case is reversed, the output of the comparator (80) becomes “H”, and the diode (90) becomes Because of the reverse bias, the output “H” of the comparator (70) is directly input to the inverter (83), and as a result, the output of the inverter (84) becomes “H”, and the output of the diode (85) and the resistor (86) becomes higher. The self-holding circuit (87) is turned on by the positive feedback. Therefore, the transistor (92) is turned on, the second relay (95) is excited, the normally open contact (95A) is closed, the hot gas solenoid valve (12) is opened, and the electric compressor (7) is turned on by turning on the power. ) Is activated, so the ice removal operation is started.

The following is a description of the respective cycle operations when starting from the ice making operation and when starting from the ice removing operation when the power is turned on.

First, when starting from the ice making operation, the ice making water supplied to the water storage tank (18) is pressure-fed to the sprinkler (16) by the circulation pump (19), and the cooling plate (2) from the sprinkler (16) is supplied. And (3) surface is flushed. The ice making water flowing down on the surfaces of the cooling plates (2) and (3) is cooled by heat conduction from an evaporation pipe (6) in which a low temperature refrigerant is circulated, and a large number of ice making buttons (4) and (5). It gradually freezes, and the unfrozen water drops from the lower ends of the cooling plates (2) and (3) into the water receiving gutter (20), is returned to the water storage tank (18), and is then sprayed again (16). ) Is repeated. As the ice making operation progresses, the outlet temperature of the evaporation pipe (6) naturally lowers, so that the terminal voltage of the ice removing and water cut detection sensor (23) rises, and as a result, the output of the comparator (80) It becomes "H" during the ice making operation.

Thus, the convex lens-like ice (136) as shown by the dotted line in FIG. 3 grows on the ice making buttons (4) and (5), and finally the ice making water at about 0 ° C. flowing on the surface of the ice (136). When comes into contact with the ice making detection sensor (22), the terminal voltage of the sensor (22) rapidly rises and the output voltage of the buffer circuit (57) also rises. The voltage at the positive input terminal of the amplifier (59) that inputs this voltage rises with the time constant of the resistor (62) and the capacitor (63), so the voltage at the negative input terminal rises quickly,
The output voltage of the amplifier (59) decreases, and further, this voltage is input to the positive input terminal and the output voltage of the buffer circuit (57) is input to the negative input terminal via the resistor (60) (64). Output is “L”, and the voltage at the negative input terminal of the comparator (66) that inputs this voltage is the resistance (6
The output voltage of the comparator (66) becomes "H" because it is lower than the bias voltage of (8) and (69), whereby the diode (74) becomes reverse bias and the comparator (70) causes the buffer circuit (57). The output of is accepted.

Then, when the output voltage of the buffer circuit (57) further rises and becomes higher than the bias voltage of the variable resistor (72) and the resistor (73) after further cooling, the output of the comparator (70) becomes “H”.
This voltage is input to the inverter (83) of the self-holding circuit (87) via the diode (88) and the resistor (89). As a result, the output of the inverter (84) becomes "H", and the self-holding circuit (87) is self-held in the ON state by the positive feedback of the diode (85) and the resistor (86).

Such a time delay operation is a detection circuit when the differential amplifier (59) and the comparator (64) detect a low temperature change, so that the ice-making detection sensor (22) detects the ice (136). Since the output of the comparator (66) is set to "H" at the moment of contact with the ice-making water flowing on the surface, when the sensor (22) is instantly cooled by some cause, for example, scattered ice-making water, ice-making is performed. This is to solve the inconvenience of outputting the end signal.

When the self-holding circuit (87) is turned on, the transistor (92) is turned on and the second relay (95) is excited, and its contact is switched from the normally closed contact (95B) to the normally open contact (95A). Wow
At the same time, the base voltage of the transistor (40) is pulled to "L" by the diode (39), so that the transistor (4
0) turns on, the power supply voltage is applied to the water supply timer (41), the timer (41) starts, "H" is output from the output terminal (41A) to turn on the transistor (47), and the first relay (50) is excited to close the normally closed contact (50A).

As a result, the circulation pump (19) and the blower (8) are stopped to end the ice making operation, the hot gas solenoid valve (12) and the water supply solenoid valve (14) are opened, and the hot gas and water are separated from each other. Start ice operation.

The reset terminal (97A) of the backup timer (97) that starts at the same time when the ice making operation starts, the diode (98) and the resistor (9
Since the output voltage “H” of the inverter (84) is input via 9), oscillation is stopped and reset at the same time.

Further, the water supply time is switched at the same time when the ice removing operation is started. That is, when the self-holding circuit (87) is turned on, the diode (116) is reverse biased, and the comparator (114) is in a state of receiving the detection output of the ambient temperature detection sensor (24). For example, when the ambient temperature detection sensor (24) detects a temperature higher than a predetermined temperature (25 ° C), the terminal voltage of the sensor (24) is low and the output voltage of the amplifier (111) is also low.
Since this voltage is lower than the bias voltage of the resistor (112) and the variable resistor (113), the output of the comparator (114) is "L".
Becomes Therefore, the comparator (11
Analog switch (4) that inputs the inverted output “H” of 4)
2) is ON, the analog switch (45) that inputs the output “L” of the comparator (114) is OFF, and the water supply time is short (30
Seconds).

On the other hand, when the ambient temperature detection sensor (24) detects a temperature equal to or lower than the predetermined temperature, the terminal voltage of the sensor (24) is high and the output voltage of the amplifier (111) is also high, and this voltage is the resistance (112).
Also, the output voltage of the comparator (114) becomes "H" because it becomes higher than the bias voltage of the variable resistor (113). Therefore,
The analog switch (42) that inputs the inverted output “L” of the comparator (114) by the inverter (115) is OFF, and the analog switch (4) that inputs the output “H” of the comparator (114)
5) is turned on and the water supply time is decided to be long (5 minutes).

Such switching of the water supply time is because the amount of heat of the hot gas circulated in the evaporation pipe (6) due to the start of the ice removing operation changes depending on the ambient temperature condition. On the contrary, if the ambient temperature is high and the ambient temperature is high, the deicing time is shortened, and accordingly, by selecting the water supply time as described above, the deicing operation is efficiently promoted.

Then, the tap water sprinkled from the sprinkler (13) through the water supply pipe (15) flows down on the back surfaces of the cooling plates (2) and (3), and the heat sensitivity of this water and the evaporation pipe (6). The ice making buttons (4) and (5) are operated by the ice removing operation for increasing the temperature of the cooling plates (2) and (3) and the ice making buttons (4) and (5) by using the heat of the hot gas circulated in the space. When the lens ice (136) is detached from and the ice-breaking / water-off detection sensor (23) detects a predetermined rise temperature at the outlet of the evaporation pipe (6),
The terminal voltage drops, the output voltage of the amplifier (76) also drops,
Since this becomes lower than the bias voltage due to the resistors (81) and (82), the output of the comparator (80) changes from "H" to "L".
Switch to.

As a result, the inverter (8) of the self-holding circuit (87)
The input of 3) is pulled to "L" through the resistor (91) and the diode (90), and the self-holding circuit (87) is turned off. Therefore, the output of the inverter (83) is "H", and the output of the inverter (8
The output of 4) becomes "L", the transistor (92) turns off, the excitation of the second relay (95) is released, and its contact switches from the normally open contact (95A) to the normally closed contact (95B). The hot gas solenoid valve (12) is closed to end the ice removing operation, and at the same time, the circulation pump (19) and the blower (8) are operated to start the ice making operation of the next cycle.

Note that the ice water that has dropped from the water inlet (1A) to the water receiving trough (20) by the water supply operation that is performed to accelerate the ice removing operation is supplied to the water storage tank (18) and used for the ice making operation of the next cycle. Sensor (2
If the water supply timer (41) has passed the specified water supply time before the 3) detects ice formation, the voltage of the output terminal (41A) of the water supply timer (41) changes from "H" to "L". "
, The transistor (47) is turned off, and the first relay (5
0) deenergize to open the normally open contact (50A), close the water supply solenoid valve (14) to end the water supply operation, and the water supply timer (41) sets the specified water supply time for the specified time. If the ice removal / water breakage detection sensor (23) detects ice removal before the elapse, the diode (39) is turned off by turning off the self-holding circuit (87).
Is reverse biased, the transistor (40) turns off and the power supply to the water supply timer (41) is cut off, which turns off the transistor (47) and deenergizes the first relay (50) to normally open it. The contact (50A) is opened, and the water supply solenoid valve (1
4) is closed to end the water supply operation.

In general, the latter case is less likely to end the water supply operation, and even if the water supply operation ends before the selected predetermined time, the minimum amount of water required for the ice making operation of the next cycle is shorter than the short water supply time. It will be secured in an even shorter time.

The above is the description of the operation when starting from the ice making operation when the power is turned on. When the operation starts from the ice removing operation when the power is turned on, hot ice circulation to the evaporation pipe (6) causes the ice removing and water cut detection sensor ( When 23) detects a predetermined temperature rise at the outlet of the evaporation pipe (6), the terminal voltage of the sensor (23) drops and the output voltage of the amplifier (76) also drops, which results in resistors (81) and (82). ), The output of the comparator (80) switches from "H" to "L".

As a result, the inverter (8) of the self-holding circuit (87)
The input of 3) is pulled to "L" through the resistor (91) and the diode (90), and the self-holding circuit (87) is turned off. Therefore, the output of the inverter (83) is "H", and the output of the inverter (8
The output of 4) becomes "L", the transistor (92) turns off, the excitation of the second relay (95) is released, and its contact switches from the normally open contact (95A) to the normally closed contact (95B). The hot gas valve (12) is closed to end the deicing operation, and at the same time, the circulation pump (19) and the blower (8) are operated to start the ice making operation. Subsequent operations are the same as those started from the ice making operation as described above.

Next, when the ice making detection circuit (52) based on the ice making detection sensor (22) cannot detect the end of the ice making operation, a timer circuit (9) forcibly ending the ice making operation and the ice removing operation.
The operation of 6) will be explained. The backup timer (97) starts simultaneously with the start of ice making operation.

That is, when the self-holding circuit (87) is turned off, the output “L” of the inverter (84) is input to the reset terminal (97A), the backup timer (97) starts oscillating, and at this time, the timer (97) The output is “L”, the analog switch (104) for inputting the inverted output “H” of the timer (97) by the inverter (103) is ON, and the analog switch (105) for inputting the output “L” of the timer (97). ) Is OFF, the backup timer (97) oscillates in a long cycle, and the output of the backup timer (97) switches from “L” to “H” after a predetermined ice making time (40 minutes) has elapsed.

Then, the output of the inverter (103) becomes "L",
Since the input of the inverter (84) of the self-holding circuit (87) is pulled to “L” via the diode (106), the output of the inverter (84) becomes “H” and the transistor (92) becomes
When turned on, the second relay (95) is excited, its contact is switched from the normally closed contact (95B) to the normally open contact (95A), and the input of the inverter (84) is further changed via the diode (106). Inverter (83) by positive feedback because it is pulled by L
Output becomes "L" and the base voltage of the transistor (40) is pulled to "L" by the diode (39), so that the transistor (40) is turned on and the power supply voltage is applied to the water supply timer (41). The timer (41) starts, outputs "H" from the output terminal (41A), and turns on the transistor (47).
N, the first relay (50) is excited to close the normally open contact (50A).

As a result, the circulation pump (19) and the blower (8) are stopped to end the ice making operation, and the hot gas solenoid valve (12) and the water supply solenoid valve (14) are opened to separate the hot gas and water together. Start ice operation.

On the other hand, the output "H" of the inverter (84) is pulled to "L" via the diode (98), the resistor (99) and the diode (107), so that the voltage of the reset terminal (97A) continues to "." It is held at L ”and the backup timer (9
7) continues to oscillate. At this time, the output of the backup timer (97) is switched from "L" to "H" so that the analog switch (104) is turned off and the analog switch (105) is turned on. Since it is turned on, the oscillation becomes a short cycle.

When the predetermined ice-free time (5 minutes) has elapsed, the output of the backup timer (97) is switched from "H" to "L", and the output of the inverter (103) becomes "H",
The diodes (106) and (107) are reverse-biased, "H" is input to the inverter (84) of the self-holding circuit (87), the output of the inverter (84) becomes "L", and the transistor (92). ) Is turned off, the excitation of the second relay (95) is released, and its contact changes from the normally open contact (95A) to the normally closed contact (95A).
Switching to B), the hot gas solenoid valve (12) is closed to end the ice removing operation, and at the same time, the circulation pump (19) and the blower (8) are operated to start the ice making operation of the next cycle. Note that the water supply operation is completed by the backup timer (97) for 5 minutes, so if the water supply time is short, it ends before the ice removal operation ends, and if the water supply time is long, the ice supply operation ends at the same time. To do.

Next, the water cut detection operation will be described. When the ice making operation is performed in a state where the water supply tank (18) is not supplied with the ice making water by the water supply operation, the outlet temperature of the evaporation pipe (6) decreases, and along with this, the ice removing and water cutoff detection sensor (23) The terminal voltage of the amplifier rises, and the output voltage of the amplifier (76) also rises. Finally, a sensor (2
3) is the specified lowering temperature (−25 at the outlet of the evaporation pipe (6)
(° C) is detected, the voltage of the positive input terminal of the comparator (132) becomes higher than the bias voltage of the resistor (130) and the variable resistor (131), and the output of the comparator (132) becomes “H”, and the AND circuit. It is input to (133). On the other hand, since the oscillation pulse is constantly input from the oscillation circuit (126) to the other input of the AND circuit (133) at a constant cycle, the output of the AND circuit (133) is equal to the oscillation cycle of the oscillation circuit (126). "H"
And "L" are repeated, and the transistor (13
Since 4) is turned on and off, the water shutoff alarm LED (135) blinks,
Notify water outage.

When the water break alarm is issued in this way, the backup timer (97) forcibly terminates the ice making operation and the ice removing operation, and then the water supply operation is restarted, the ice removing and water interruption detection is performed. The water cut alarm is canceled by the water sensor (23).

Next, a high temperature detecting operation caused by clogging of the filter (25) will be described. For example, when the filter (25) is clogged, the outlet temperature of the condenser (9) rises, the terminal voltage of the ambient temperature detection sensor (24) decreases accordingly, and the output voltage of the amplifier (111) also decreases. descend. Then, when the ambient temperature detection sensor (24) finally detects a predetermined rise temperature (63 ° C.) at the outlet of the condenser (9), the comparator (11
The voltage at the negative input terminal of 9) is the resistance (117) and (11
It becomes lower than the bias voltage by 8), the output of the comparator (119) becomes "H", and is input to the AND circuit (127). On the other hand, since the oscillation pulse is constantly input from the oscillation circuit (126) to the other input of the AND circuit (127) at a constant cycle, the output of the AND circuit (127) is the oscillation circuit (12).
Repeats "H" and "L" in the oscillation cycle of 6), and the transistor (128) turns on and off in synchronization with this, so the high temperature alarm
The LED (129) blinks to notify the abnormal high temperature of the condenser (9).

When a high temperature alarm is issued in this way, identify the cause, and if the filter (25) is clogged, clean the filter (25) to allow the ambient temperature detection sensor (24) to generate a high temperature alarm. To release.

Although the preferred embodiment of the flow-down type ice making machine of the present invention has been described above, the present invention is not necessarily limited to the embodiment and can be modified within a range not departing from the gist of the present invention, and particularly, The numerical values listed in the examples are not limited to these values, and are set in consideration of the relationships such as the refrigerating capacity, the detection place and the structure.

(G) Effect of the Invention As described above, the present invention relates to a water shutoff detection device for a downflow type ice making machine, in which hot gas is circulated in an evaporator pipe provided in a cooler, and ice is frozen in the cooler. The ice removal / water breakage detection sensor provided in the evaporation pipe and the output of the ice removal / water breakage detection sensor receive the ice due to the predetermined rise temperature of the cooler by the ice removal operation, and the water storage tank During the ice making operation performed by circulating the supplied ice making water to a cooler and circulating a low temperature refrigerant to the evaporation pipe, a detection circuit for detecting water cutoff due to a predetermined lowered temperature of the cooler, and a detection circuit of the detection circuit. Since the notifying means for notifying the water interruption by operating based on the water interruption signal is provided, the special water interruption detecting means is not necessary, and the water interruption detecting device can be obtained at a low cost, and the ice removing and water interruption detecting sensor is Withdrawal and disconnection Water and water can be reliably detected by the temperature of the cooler.

Further, since the ice removing / water breakage detecting sensor of the present invention is attached to the evaporation pipe, it is easier to install than an outside place, and moreover, the ice removing / water breakage detecting sensor attached to the evaporation pipe. Since there is no concern that the deicing / water breakage detection sensor will malfunction due to clogging of the surroundings of the, the temperature of the evaporation pipe, that is, defrosting and water cutoff can be reliably detected.

[Brief description of drawings]

FIG. 1 is a control electric circuit diagram of a downflow type ice making machine equipped with the device of the present invention, and FIG. 2 is a perspective view of the same downflow type ice making machine.
The figure is also a system configuration diagram of a downflow type ice making machine. (1) ... Cooler, (12) ... Hot gas solenoid valve, (18) ...
Water tank, (23) ... Ice-freeness detection sensor, (135) ... Water interruption alarm LED.

Front page continued (72) Inventor Shigeo Sato 180 Sakata, Oizumi-cho, Gunma-gun Oozumi-cho, Tokyo Sanyo Electric Co., Ltd. In-house (72) Inventor Nobuyuki Shioshima 180 Sakata, Oizumi-cho, Gunma-gun Oozumi-cho, Tokyo Sanyo Electric Co., Ltd. (56) References: 60-82177 (JP, U) , U)

Claims (1)

[Claims] 1. A dewatering detection device for a downflow type ice making machine, wherein hot gas is circulated through an evaporation pipe provided in a cooler to perform ice removal operation of frozen ice in the cooler. In response to the output of the water break detection sensor and the ice release / water break detection sensor, the ice is separated due to the predetermined rising temperature of the cooler due to the ice removing operation, and the ice making water supplied to the water storage tank is supplied to the cooler. During the ice making operation performed by circulating a low-temperature refrigerant in the evaporation pipe while circulating, a detection circuit for detecting water cutoff due to a predetermined lowered temperature of the cooler, and water cutoff by operating based on the water cutoff signal of the detection circuit. A water cutoff detection device for a downflow type ice maker, comprising: an informing means for informing.