JP2583937B2 - Ice making equipment such as refrigerators - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ice making device capable of producing transparent ice.

2. Description of the Related Art Conventionally, in a home refrigerator or the like, an ice making device for storing an ice tray is arranged in a part of a freezing room, and the water in the ice tray is frozen by the cooling action of cold air flowing through the ice making device. Is generally performed.

However, with such an ice generation method, the freezing of water in the ice tray when ice is generated proceeds from the contact surface between the ice tray and water and the contact surface between cold air and water to the center. Therefore, the gas component dissolved in the water is contaminated with impurities in the center of the ice, resulting in opaque ice with a cloudy center in the center, for example, sensually suitable for beverages such as whiskey Did not.

Therefore, there is a need for transparent ice from the past,
For the device for producing it, see, for example,
A method has been considered as disclosed in JP-A-69779. Hereinafter, the basic configuration and operation will be described with reference to FIGS. 4 to 6.

1 is a refrigerator body, 2 is a partition wall 3
Is a freezer compartment formed in the upper part of the refrigerator. 4 is a cooler of the refrigerating cycle housed in the partition wall 3, 5 is a blower for forcibly ventilating the cool air cooled by the cooler 4 to the freezer 2, and 6 is a blower for the freezer 2 It is a duct that leads. Reference numeral 7 denotes an ice making device provided at a lower portion of the freezing room 2. Reference numeral 8 denotes an aluminum made at a predetermined interval from a lower end of the ice making device 7, and an inner end thereof protrudes into the duct 6. It is a cooling plate. Reference numeral 9 denotes an ice tray placed on the cooling plate, 10 denotes an aluminum heating plate provided on the upper surface of the ice tray 9, and a heater 11 is disposed on the back surface of the heating plate 10 in close contact therewith. I have. Reference numeral 12 denotes a heat insulating material disposed so as to cover the outer periphery of the ice tray 9 excluding the lower surface and the front surface, and 13 denotes an air passage formed below the cooling plate 8. Reference numeral 14 denotes a temperature sensor such as a thermistor provided in a part of the freezing chamber 2 for controlling the operation of the compressor 15 of the refrigeration cycle and the blower 5, and 16 denotes the temperature sensor for generating transparent ice. Heater 11
This is an ice making switch that instructs power supply to the device. Further, reference numeral 17 denotes a defrost heater for defrosting the cooler 4, and reference numeral 18 denotes a temperature sensor provided near the cooler 4 to detect a defrost end temperature of the defrost heater 17.

Next, an electric circuit will be described. After the blower 5 and the compressor 15 are connected in parallel, the blower 5 and the compressor 15 are connected to the power supply via the a contact of the switching relay contact 19 and the relay contact 20. Further, the defrost heater 17 is connected to a power supply via the contact b of the switching relay contact 19 and the relay contact 20. And
The heater 11 is connected to a power source after being connected in series with the relay contact 21.

Next, the control circuit will be described. 22 is a freezing compartment temperature control device, the temperature sensor 14, the resistor _{R 1, R 2, R 3} , comparator circuit having a comparator 23, transistor 24, and a relay coil 25, the output of the comparator 23 It is connected to the base of the transistor 24. Further, a collector coil of the transistor 24 is connected to a relay coil 25 for suction for opening and closing the relay contact 20. 26 is a defrosting control unit, the temperature sensor 18, the resistor R _4, R _5, R ₆ comparator circuit defrosting timer 28 which includes a comparator 27, transistor 29, and a relay coil 30, the comparator 27 The output is connected to the reset terminal of the timer 28, and the input terminal of the defrost timer 28 is connected to input the output signal of the comparator 23 of the freezing room temperature control device 22. Here, the defrost timer 28 is configured to output an “H” signal when an “H” signal is integrated and input for a predetermined time.

The output of the defrost timer 28 is output from the transistor 29
And a collector of the transistor 29 is connected to an attraction relay coil 30 for switching the contact of the switching relay contact 19. Next, 31 is an ice making control device, and the ice making switch 16, timer 32, transistor
33, consisting of a relay coil 34, the output of the ice making switch 16 is connected to the input of the timer 32, and the output of the timer 32 is connected to the base of the transistor 33, and the collector of the transistor 33 opens and closes the relay contact 21. A relay coil for suction is connected. Here, once the “H” signal is inputted, the timer 32 is set to a predetermined time (t ₀ ).
During this time, an “H” signal is output.

In such a configuration, normally, when the temperature of the freezing compartment 2 is higher than a predetermined value, the resistance value R _TH1 of the temperature sensor 14 decreases, and the output of the comparator 23 outputs a “High” signal (hereinafter abbreviated as “H”). As a result, the transistor 24 turns on and the relay coil 25 conducts. Then, the relay contact 20 is turned on, and the compressor 15 connected to the a contact side of the switching relay contact 19 is turned on.
And the cooler 4 performs a cooling operation. At the same time, the blower 5 is operated, and the cool air cooled by the cooler 4 is forcibly blown into the freezing room 2 through the duct 6 to perform a cooling action. Thereafter, when the freezing compartment 2 is cooled to a predetermined temperature, the resistance value R _TH1 of the temperature sensor 14 increases, and a low signal (hereinafter abbreviated as “L”) is output to the output of the comparator 23. Therefore, transistor 24 is turned off.
The conduction to the relay coil 25 is interrupted and the relay contact 20
Is turned off, the compressor 15 and the blower 5 are stopped, and the cooling action is also stopped. Thereafter, this operation is repeated to perform a normal cooling operation.

Next, during such a cooling operation, when an “H” signal is integrated for a predetermined time and input to the input of the defrost timer 28, the timer 28 is deactivated.
Is output, an "H" signal is generated, the transistor 29 is turned on, the relay coil 30 is turned on, and the switching relay contact is switched to the contact b. Therefore, the operation of the compressor 15 and the blower 5 is stopped, and power is supplied to the defrost heater 17 instead. Then, the cooler 4 is defrosted by the heat generation action of the defrost heater 17. When the temperature of the cooler 4 rises sufficiently and the temperature sensor 18 reaches a predetermined temperature, the resistance value R _TH2 decreases and an “H” signal is output to the output of the comparator 27, and the defrost timer
Input to 28 reset terminal. For this reason the defrost timer
The output of 28 is reset to “L” signal and the transistor
29 is turned off, the conduction of the relay coil 30 is cut off, the contact of the switching relay contact 19 is switched to the contact again, and the defrosting is completed. Then, the compressor 15 and the blower 5 are operated to restart the cooling operation.

Next, when the user puts the ice tray 9 filled with water into the ice making device 7 at the same time as turning on the ice making switch 16 to make transparent ice during the cooling operation as described above,
An “H” signal is output and input to the timer 32. The timer 32 continues to output the “H” signal for a predetermined time (t ₀ ). During this time, the transistor 33 is turned on, the relay coil 34 is turned on, the relay contact 21 is turned on, and the heater 11 is energized. On the other hand, a part of the cool air flowing through the duct 6 is guided from the far end of the cooling plate 8 into the ventilation passage 13 formed below the ice making device 7 to cool the cooling plate 8. For this reason, the water in the ice tray 9 is cooled from the lower surface by the cooling action of the cooling plate 8 and is heated from the upper face by the heating action of the heating plate 10 due to the heat generated by the heater 11. A one-way slow cooling ice making operation in which freezing proceeds toward the upper surface is performed. When the freezing speed toward the upper surface is sufficiently low in this way, the traveling speed of the frozen surface of ice is slower than the speed at which the gas component in the water diffuses upward, and the water component of the gas component in the vicinity of the freezing surface is underwater. The dissolution concentration is reduced and the chance of generating bubbles is reduced. Even if bubbles are generated, the generated bubbles are not trapped in the ice because the freezing speed is low. For this reason, the gas component in the water is degassed into the outside air from the surface of the water that freezes last, and the finally generated ice contains almost no air bubbles and provides clear ice. Further, when the timer 32 counts a predetermined time (t ₀ ) which is determined by giving a certain margin to the time required for completing the ice making, the output becomes “L” and the transistor 33 is turned off. For this reason, the conduction of the relay coil 34 is cut off, the relay contact 21 is turned off, the power supply to the heater 11 is stopped, and the ice making control ends.

However, when the heater 11 unconditionally generates heat for a predetermined time (t ₀ ) by turning on the ice making switch 16 as described above, the integration time of the defrost timer 28 during the ice making operation is reduced. When the defrosting operation is started, the cold plate operation by the cooling plate 8 is stopped and the temperature in the freezing compartment 2 is increased by the defrosting operation, so that the heating is performed as shown in FIG. Board 10
Temperature rises sharply to a considerable temperature. At the same time, the temperature of the cooling plate 8 also suddenly rises to a high temperature (plus temperature), and the overall cooling action stops, and the freezing progress stops or the freezing retreats (the generated ice partially melts). And the final ice-making completion time (t) is prolonged.

Separately, the user places the ice-making tray 9 filled with water on the cooling plate 8 without turning on the transparent ice-making switch 16 for the purpose of not requiring transparent ice. In this case, since the heater 11 is not energized, the moisture of the steam generated during the ice making operation mainly adheres to the heating plate 10 close to the water surface as dew, and then develops as frost. If the amount of frost is large, there is also a problem that the ice tray 9 is disturbed in and out.

The present invention has been made to solve the above-described problems, and prevents the ice making time from being extended due to the defrosting action during ice making of transparent ice,
It is an object of the present invention to prevent frost from forming near an ice tray when making ice when transparent ice is not required.

Means for Solving the Problems In order to solve the above problems, an ice making device such as a refrigerator of the present invention stops the operation of the heating means of the heating plate when defrosting the cooler during the ice making operation of transparent ice. In addition to the configuration, the heating means of the heating plate is operated at the time of defrosting of the cooler during a period other than during the ice making operation of the transparent ice.

Operation In the present invention, the operation of the heating means is stopped at the time of defrosting during the ice making operation of transparent ice by the above-described structure, and the temperature rise is suppressed without heating the heating plate. For this reason, the temperature of the cooling plate also does not rise to the plus temperature zone, and even during defrosting, the cooling action is maintained to some extent, and the freezing action proceeds gradually. On the other hand, when making ice without the need for transparent ice, the heating means operates during the defrosting of the cooler, in which the frost mainly due to the dew attached to the heating plate during the ice making, this operation is performed. Sometimes the heating plate is sufficiently heated to remove the attached dew and frost.

Embodiment An embodiment of an ice making device such as a refrigerator according to the present invention will be described below with reference to FIGS. Note that the same components as those of the related art are denoted by the same reference numerals, and detailed description thereof will be omitted. An ice making device 35 is different from the conventional example only in the control device.

36 is an ice making control device, an ice making switch 16, a timer
37, AND circuits 38 and 39, inverters 40 and 41, an OR circuit 42, a transistor 33, and a relay coil 34 are provided. Here, the timer 37 is once "H" signal is input, is configured to continue to output the "H" signal for a predetermined time (t ₀ '). The output of the ice making switch 16 is the timer
37, and the output of the timer 37 is connected to the AND circuit 3
8 and one input of an AND circuit 39 via an inverter 41. The output of the defrost timer 28 of the defrost control device 26 is supplied to the other input of the AND circuit 38 via the inverter 40, and the output of the defrost timer 28 is supplied to the other input of the AND circuit 39. Connected at the same time. Further, the respective outputs of the AND circuits 38 and 39 are connected to the input of an OR circuit 42, the output of the OR circuit 42 is connected to the base of the transistor 33, and the collector of the transistor 33 is connected to a relay contact.
A relay coil 34 that opens and closes 21 is connected.

In such a configuration, during the ice making operation with the ice making switch 16 turned on, if the defrost timer 28 of the defrost control device 26 integrates a predetermined time and enters a defrosting operation, the defrost timer 28
The "H" signal of the output is converted to "L" by the inverter 40, and one input of the AND circuit 38 is set to "L". Therefore, the output of the AND circuit 38 becomes “L”. On the other hand, since the output “H” of the timer 37 is converted to “L” by the inverter 41 and input to the AND circuit 39, the output is also “L”. Therefore, the output of the OR circuit 42 becomes “L”, the transistor 33 is turned off, and the conduction of the relay coil 34 is cut off. Then, the relay contact 21 is turned off, and the energization of the heater 11 is interrupted.
Therefore, the temperature of the heating plate 10 does not rise as shown in FIG. During the defrosting operation, the temperature of the cooling plate 8 gradually increases due to the heat generated by the defrosting heater 17, so that the water in the ice tray 9 has a certain cooling capacity overall. While the defrosting is proceeding, the water freezing operation is gradually performed from the lower surface to the upper surface during the defrosting, and the ice making operation proceeds without interruption or retreat.
Accordingly, the final ice making completion time (t ') is considerably shorter than the conventional time (t).

On the other hand, when the defrosting time of the cooler 4 has come when the ice making switch 16 is not turned on, the output of the timer 37 is "L" and one of the inputs of the AND circuit 38 is "L". And the output also becomes “L”. However, as for the AND circuit 39, the output “L” of the timer 37 is converted into “H” by the inverter 41 and becomes one input “H”. Since the output of the defrost timer 28 also becomes "H", the other input also becomes "H" and the output of the AND circuit 39 becomes "H". Therefore OR
The output of the circuit 42 also becomes “H”, the transistor 33 is turned on, and the heater 11 is energized. For this reason, even if the ice tray 9 is filled with water for ice making without turning on the ice making switch 16 for the purpose of not requiring transparent ice, the heating plate 10
Even if dew or frost adheres, the heating plate 10 is heated at the time of defrosting and can be removed, so that the ice tray cannot be taken in and out due to frosting.

Effect of the Invention As described above, according to the ice making device such as the refrigerator of the present invention, the power supply to the heating means of the ice making device is stopped at the time of defrosting during the ice making operation of transparent ice. This has the effect that the freezing action progresses and the final ice making completion time can be shortened, and the ice making time does not become unnecessarily long due to the intervention of defrosting. In addition, since the heating means is operated during defrosting during periods other than when making clear ice, dew condensation around the ice tray that occurs during ice making that does not require clear ice must be removed by heating. This prevents the ice tray from being taken in and out due to frost formation.

[Brief description of the drawings]

FIG. 1 is a control circuit diagram of an ice making device such as a refrigerator showing an embodiment of the present invention, FIG. 2 is a temperature characteristic diagram during ice making by the ice making device, and FIG. FIG. 4 is a sectional view of a main part of a refrigerator provided with a conventional ice making device, FIG. 5 is an electric circuit and a control circuit diagram of the ice making device, and FIG. 6 is a temperature characteristic during ice making by the ice making device. FIG. 2 ... freezer compartment (cooling compartment), 4 ... cooler, 8 ... cooling plate (cooling means), 9 ... ice tray, 11 ... heater (heating means), 16 ... ice making switch, 35 ... Ice making equipment, 36 ... Ice making control equipment.

Claims (1)

(57) [Claims] 1. A cooling plate provided in a part of a cooling room cooled by cool air from a cooler, an ice making room defined by defining the cooling plate as a bottom surface and opening a front surface, and housed in the ice making room. An ice tray placed on the cooling plate, a heating plate provided with a heating means such as a heater provided on the upper surface of the ice tray, and a heat insulating material disposed in an outer wall excluding a bottom surface and a front surface of the ice making chamber. An ice making switch for instructing the operation of the heating means to start ice making; and stopping the operation of the heating means at the time of defrosting the cooler during the operation of the ice making switch, and stopping the operation of the ice making switch. An ice making device such as a refrigerator comprising an ice making control device for activating the heating means when the cooler is defrosted.