JPH0718628B2 - De-icing control device for downflow type ice machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Use The present invention relates to the heat of hot gas circulated to an evaporation pipe provided in the cooler and the cooler for the ice removing operation of frozen ice on the surface of the cooler. The flow-down type ice making machine, which is used together with the heat of the water flowing down to the back side of the ice, and collects this ice-breaking water in a water storage tank and reuses it as ice-making water for the next cycle. .

(B) Conventional Technology A conventional ice making machine that performs an ice removing operation by using both heat sensitivity of water and hot gas is disclosed in Japanese Utility Model Laid-Open No. 59-11273, for example.
V) and the hot gas solenoid valve (HV) are operated for a predetermined time to perform ice removing operation.

(C) Problems to be Solved by the Invention Such a conventional ice-breaking method significantly increases the water supply amount and a large amount of water from the water storage tank especially when the ambient temperature is low and the ice-release time is long. It left a problem of draining.

(D) Means for Solving the Problems In the present invention, the ice removing operation of the ice frozen on the surface of the cooler is performed by using the heat of hot gas and the heat sensitivity of water together, and In a downflow type ice making machine that collects in a water storage tank and reuses it as ice making water for the next cycle, based on the completion of the ice making detection sensor and the ice making detection sensor that detects the detachment of ice substantially at a predetermined rising temperature of the cooler. A hot gas solenoid valve that opens to circulate hot gas to the evaporation pipe and closes to stop hot gas circulation based on detection of ice removal by the ice removal detection sensor, and water for ice removal to the cooler. A water supply solenoid valve for controlling water flow, and a start signal based on the end of the ice making operation, and at the same time, outputs an opening signal of the water supply solenoid valve, and when the selected water supply time of the two short and long water supply times has elapsed, the water supply Solenoid valve closing signal , A ambient temperature detection sensor for detecting the outlet temperature of the condenser, and a short time when the sensor detects a temperature higher than a predetermined temperature, the sensor detects a temperature lower than the predetermined temperature. This is an ice removal control device for a downflow type ice making machine which solves the problems of the prior art by providing a switching device for switching the water supply time of the water supply timer for a long time when the water supply is on.

(E) Action In the present invention, the hot gas solenoid valve (12) is opened to circulate the hot gas in the evaporation pipe (6) upon completion of the ice making operation, and at the same time, the water supply solenoid valve (14) is opened. Then, deicing water is run on the back surface of the cooler (1), and the deicing operation is started by the combined use of the heat of the hot gas and the heat sensitivity of the water. Here, the water supply timer (41) that controls the opening / closing valve of the water supply solenoid valve (14)
When the ambient temperature detection sensor (24) detects a temperature higher than the specified temperature, the analog switch (42) turns on to function as a short-time timer to shorten the water supply time and detect a temperature lower than the specified temperature. The analog switch (45) turns on and becomes a long time timer to extend the water supply time.

(F) Embodiments Embodiments of the present invention will be described below with reference to the drawings. First,
The structure of the flow-down type ice making machine of the present invention will be described with reference to FIGS. 2 and 3. A cooler (1) for freezing ice making water.
Is a pair of cooling plates (2) arranged substantially vertically with a space therebetween.
And (3) and a large number of the cooling plates (2) and (3), which are arranged at intervals in the vertical and horizontal directions and are exposed substantially flush with the surfaces of the cooling plates (2) and (3). Round ice making button (4)
And (5) and the cooling plates (2) and (3) on the back side in a meandering manner, and the ice making button (4) on one cooling plate (2) side.
And the evaporation pipe (6) sandwiched by the ice making buttons (5) on the other cooling plate (3) side.

Further, the electric compressor (7), the condenser (9) forcibly cooled by the blower (8), and the expansion valve (10) as a pressure reducing device.
The refrigerant circuit formed by annularly connecting the evaporation pipe (6) and the like includes a hot gas bypass pipe (11) for circulating hot gas in the evaporation pipe (6) and a hot gas solenoid valve (12). ing.

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 placed in front of the ice making button (4) at a predetermined interval so as to sense the temperature of water flowing on the surface of frozen ice on the ice making button (4), thereby cooling the ice making button (4). The ice-making detection sensor for detecting the growth of predetermined ice in the vessel (1), (23) is arranged so as to detect the outlet temperature of the evaporation pipe (6), so that the ice is separated from the cooler (1). And the deicing detection sensor for detecting water interruption, (24) is arranged so as to detect the outlet temperature of the condenser (9), which is dependent on the ambient temperature, and indirectly senses the ambient temperature to supply water. This is an ambient temperature detection sensor for detecting an abnormally high temperature of the condenser (9) caused by switching of the switch 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 forcibly setting the output of the buffer circuit (57) to "H" when the power is turned on, (59) ) Is a 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) is an amplifier in which the connection point voltage between the resistor (77) and the ice detection sensor (23) is connected to the positive input terminal and the connection point voltage between the resistor (78) and the variable resistor (79) is connected to the negative input terminal. , (80) are comparators 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. In the embodiment, the sensor (23) Switches the output of the comparator (80) from "H" to "L" when it detects a predetermined rise temperature (8 ° C).

The output of the ice making detection circuit (52), that is, the comparator (70)
The output of the self-holding circuit (87) composed of the inverters (83) and (84) and the diode (85) and the resistor (86) connected between the input of the inverter (83) and the output of the inverter (84). Is connected to the input of the inverter (83) via a diode (88) and a resistor (89). On the other hand, the output of the ice release detection circuit (75), that is, the output of the comparator (80) is output from the diode (90) and the resistor (89) whose forward direction is toward the output terminal of the comparator (80). It is connected to the input of the inverter (83) of the self-holding circuit (87) via a resistor (91) having an extremely small resistance value. (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), (95)
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.

The circuit for controlling the switching of the water supply time described above includes an ambient temperature detection sensor (24) using a transistor sensor and a resistor (10) as in the ice removal detection sensor (23).
The amplifier (111) in which the connection point voltage of 8) is connected to the positive input terminal and the connection point voltage of the resistor (109) and the variable resistor (110) is connected to the negative input terminal, and the output of the amplifier (111) is positive. A comparator (114) connected to the input terminal and connected to the minus input terminal of the bias voltage generated by the resistor (112) and the variable resistor (113) is provided, and the output of the comparator (114) is passed through the inverter (115). It is configured by connecting to the one analog switch (42) and directly connecting the output of the comparator (114) to the other analog switch (45). In the embodiment, when the sensor (24) detects a temperature higher than the predetermined temperature (25 ° C.), the comparator (114)
Output is "L", and the output of the comparator (114) is "H" when a predetermined temperature or less is detected. The comparator (11
The diode (116) whose forward direction is the direction from the positive input terminal of 4) to the output of the self-holding circuit (87) functions so that the switching of the water supply time is performed only at the time of 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 ice-ice detection sensor (23) also serves as a sensor, and the output of the amplifier (76) is connected to the positive input terminal and the bias voltage from the resistor (130) and variable resistor (131) is connected to the negative input terminal. (132)
And the output of the comparator (132) as one input and the output of the oscillation circuit (126) as the other input (1
33), a transistor (134) that receives the output of the AND circuit (133), and a water cutoff alarm LED (135) as a notification means that blinks in synchronization with ON / OFF of the transistor (134). In the example, 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 through the normally open contact (50A) of the first relay (50), and the hot gas solenoid valve is connected through the normally open contact (95A) of the second relay (95). (12)
And a parallel circuit of the circulation pump (19) and the blower (8) are connected via a normally closed contact (95B).

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, tap water sprinkled from the sprinkler (13) through the water supply pipe (15) flows down the back surfaces of the cooling plates (2) and (3), and the water supply port (1A at the lower end of the cooler (1) ) From the water gutter (2
It is dropped and collected in 0) and is supplied to the water storage tank (18).

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. In addition, the input of the inverter (32) is set to "L" via the diode (51).
The self-holding circuit (29) is turned off to pull the diode (36), and the anode of the diode (36) becomes "H", so that the transistor (40) is turned off and the water supply timer (41) 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 at the positive input terminal of the differential 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 and the differential amplifier (59 ) Output voltage decreases, and further, the output of the comparator (64) which inputs this voltage to the plus input terminal and the output voltage of the buffer circuit (57) to the minus input terminal becomes "L". When input, the voltage at the negative input terminal of the comparator (66) becomes lower than the bias voltage due to the resistors (68) and (69), and the output of the comparator (66) becomes "H", which causes the diode (74) to reverse. It becomes a bias, the comparator (70) receives the output of the buffer circuit (57), the voltage of the positive input terminal becomes higher than the bias voltage by the variable resistor (72) and the resistor (73), and the comparator (70)
Becomes "H", 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 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 as a result, the amplifier (76 )
Since the output voltage of the comparator (80) also decreases, the voltage at the positive input terminal of the comparator (80) becomes lower than the bias voltage due to the resistors (81) and (82), and the output of the comparator (80) becomes "L", The input of the inverter (83) of the holding circuit (87) is a resistor (9
It is pulled to "L" through 1) and the diode (90), and the self-holding circuit (87) is turned off. That is, the output of the inverter (83) is "H", the output of the inverter (84) is "L", the transistor (92) is not turned on, and the second relay (95) is not excited. Therefore, the circulation pump (19) and the blower (8) operate via the normally closed contact (95B) of the second relay (95), and the electric compressor (7) operates when the power is turned on, so that the ice making operation is started. .

On the other hand, when the ice release 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) is reverse biased. Therefore, 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 positive feedback of the diode (85) and the resistor (86) is performed. The self-holding circuit (87) is turned on. 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. )
Will start the ice removal operation.

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 water tank (1
The ice making water absorbed in 8) is pressure-fed to the sprinkler (16) by the circulation pump (19), and is made to flow from the sprinkler (16) to the surfaces of the cooling plates (2) and (3). 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 separation detecting sensor (23) rises, and as a result, the comparator (8
The output of 0) 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 due to the time constant of the resistor (62) and capacitor (63), so the voltage at the negative input terminal rises quickly and the output voltage of the amplifier (59) is increased. The output of the comparator (64) which inputs this voltage to the plus input terminal and the output voltage of the buffer circuit (57) to the minus input terminal through the resistor (60) becomes "L". , The voltage of the negative input terminal of the comparator (66) that inputs this voltage is the resistance (68)
And (69) lower than the bias voltage and the comparator (6
The output voltage of 6) becomes "H", whereby the diode (74) is reverse biased, and the comparator (70) is in a state of receiving the output of the buffer circuit (57).

After that, 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”, and 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). At the same time, since the base voltage of the transistor (40) is pulled to "L" by the diode (39), the transistor (40)
Is turned on, the power supply voltage is applied to the water supply timer (41), the timer (41) is started, "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, the ice making operation is completed, and the hot gas solenoid valve (1
2) and the water supply solenoid valve (14) are opened, and the deicing operation is started by using hot gas and water together.

The reset terminal (97A) of the backup timer (97) that starts at the same time as the start of the ice making operation turns on the self-holding circuit (87) to turn on the diode (98) and resistor (99).
Since the output voltage “H” of the inverter (84) is input via the, the 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, if the ambient temperature sensor (24)
When detecting a temperature higher than ℃), the terminal voltage of the sensor (24) is low and the output voltage of the amplifier (111) is also low, and this voltage is lower than the bias voltage of the resistor (112) and the variable resistor (113). The output of the comparator (114) becomes "L". Therefore, the analog switch (42) for inputting the inverted output “H” of the comparator (114) by the inverter (115) is O.
N, the analog switch (45) for inputting the output “L” of the comparator (114) is turned off, and the water supply time is determined to be a short time (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 to the ice making buttons (4) and (5). When the lens ice (136) comes off from the ice cube and the ice-breakup detection sensor (23) detects a predetermined temperature rise at the outlet of the evaporation pipe (6), the terminal voltage drops and 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) switches from "H" to "L".

By this, 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. 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. If the water supply timer (41) has exceeded the specified water supply time before the ice separation detection sensor (23) detects ice formation, the water supply timer (41) output terminal (41A) ) Voltage is changed from "H" to "L", the transistor (47) is turned off, the excitation of the first relay (50) is released, the normally open contact (50A) is opened, and the water supply solenoid valve (14).
If the ice removal detection sensor (23) detects ice removal before the water supply timer (41) has passed the predetermined time of the selected water supply time, the self-holding circuit ( 8
By turning off 7), diode (39) becomes reverse bias,
The transistor (40) turns off and the power supply to the water supply timer (41) is cut off, which turns off the transistor (47).
When it becomes F, the excitation of the first relay (50) is released to open the normally open contact (50A), and the water supply solenoid valve (14) is closed to complete 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 the ice making operation is started when the power is turned on. When the ice removing operation is started when the power is turned on, the ice removing sensor (23) is activated by the hot gas circulation to the evaporation pipe (6). When a predetermined temperature rise at the outlet of the evaporation pipe (6) is detected, the terminal voltage of the sensor (23) decreases and the output voltage of the amplifier (76) also decreases, which is biased by the resistors (81) and (82). Since it becomes lower than the voltage, the output of the comparator (80) switches from "H" to "L".

By this, 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. 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, the ice making detection circuit (5
If the end of the ice making operation cannot be detected by 2), the timer circuit (96) that forcibly ends the ice making operation and the ice removing operation.
The operation of will be described. 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", and the input of the inverter (84) of the self-holding circuit (87) is pulled to "L" through the diode (106). Therefore, the output of the inverter (84) becomes It becomes "H" and the transistor (92) turns on.
Then, 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 changed to "L" through the diode (106). "
The output of the inverter (83) also becomes "L" due to the positive feedback, and the base voltage of the transistor (40) is also pulled to "L" due to the diode (39), so the transistor (40) turns on and the water supply The power supply voltage is applied to the timer (41) to start the timer (41), and the output terminal (41
Output "H" from A) and turn on the transistor (47),
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, the ice making operation is completed, and the hot gas solenoid valve (1
2) and the water supply solenoid valve (14) are opened to start the deicing operation by the combined use of hot gas and water.

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.

Then, when the predetermined ice-free time (5 minutes) has elapsed, the output of the backup timer (97) switches from "H" to "L", and when the output of the inverter (103) becomes "H", the diode (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 is from the normally open contact (95A) to the normally closed contact (95B).
, The hot gas solenoid valve (12) is closed to complete the ice removing operation, and the circulation pump (19) and blower (8)
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 supplying operation, the outlet temperature of the evaporation pipe (6) is lowered, and accordingly, the terminal voltage of the ice separation detecting sensor (23) is decreased. Rises and the output voltage of the amplifier (76) also rises. Then, when the ice separation detection sensor (23) finally detects a predetermined temperature decrease (−25 ° C.) at the outlet of the evaporation pipe (6), the voltage at the positive input terminal of the comparator (132) becomes a resistance (13
0) and the bias voltage due to the variable resistor (131), the output of the comparator (132) becomes "H" and is input to the AND circuit (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). Since "H" and "L" are repeated and the transistor (134) is turned on and off in synchronization with this, the water cutoff alarm LED (135) blinks to notify the water cutoff.

When the water outage 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 break detection sensor (23) cancels the water break alarm.

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
The present invention is not limited to this, and is 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 takes into account that the heat quantity of the hot gas circulated in the evaporation pipe changes due to the change in the ambient temperature condition. On the contrary, if the ambient temperature is high and the ambient temperature is high, the deicing time will be shortened.Accordingly, the water supply time of the water supply timer is switched to long or short to control the opening and closing of the water supply solenoid valve, so that the deicing operation is efficient. It has an excellent advantage that water can be promoted and that water can be remarkably saved as compared with the prior art.

Further, since the ambient temperature sensor detects the outlet temperature of the condenser, it is possible to detect an abnormally high temperature of the condenser.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of a downflow type ice making machine equipped with the device of the present invention, FIG. 2 is a perspective view of the downflow type ice making machine, and FIG. 3 is a system configuration diagram of the downflow type ice making machine. (1) …… Cooler, (12) …… Hot gas solenoid valve, (1
4) …… Water supply solenoid valve, (23) …… Ice removal detection sensor, (2
4) …… Ambient temperature detection sensor, (41) …… Water supply timer, (42), (45) …… Analog switch.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masahiro Kobayashi, Inventor Masahiro Koibayashi, Gunma Prefecture, Oizumi-cho 180, Sakata, Higashi Kyosanyo Electric Co., Ltd. (72) Inventor Nobuyuki Shiojima, Oizumi-cho, Gunma, Japan, 180, Sakata, Tokyo Sanyo Denki Co., Ltd. (56) References: Shown 59-7377 (JP, U) Shown 57-2866 (JP, Y2)

Claims (1)

[Claims] 1. A deicing operation of frozen ice on the surface of a cooler,
This is a flow-down system in which it is used in combination with the heat of the evaporation pipe provided in the cooler and the heat sensitivity of the water flowing down the back of the cooler, and this ice water is collected in a water storage tank and reused as water for ice making in the next cycle. In an ice making machine, an ice release detection sensor that detects detachment of ice substantially at a predetermined rising temperature of a cooler,
A hot gas solenoid valve that opens to circulate hot gas to the evaporation pipe upon completion of the ice making operation and closes to stop hot gas circulation based on the ice removal detection by the ice removal detection sensor, and a cooler A water supply solenoid valve for controlling the passage of ice-breaking water to the water supply and a start signal based on the end of the ice making operation, and at the same time, an opening signal of the water supply solenoid valve is output, and the water supply time selected from two long and short water supply times is selected. When a time elapses, a water supply timer that outputs a valve closing signal of the water supply solenoid valve, an ambient temperature detection sensor that detects the outlet temperature of the condenser, and a short time when the sensor detects a temperature higher than a predetermined temperature. An ice removal control device for a downflow type ice making machine, comprising a switching device for switching the water supply time of the water supply timer for a long time when the sensor detects a temperature lower than a predetermined temperature.