JPH0676866B2 - Ice makers such as refrigerators - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ice making device such as a refrigerator arranged in a freezer or the like of a refrigerator and capable of producing transparent ice.

2. Description of the Related Art Conventionally, in household refrigerators and the like, an ice making device for accommodating an ice making plate is arranged in one part of a freezing room, and the water in the ice making plate is frozen by the cooling action of the cold air flowing through the ice making device. Is generally generated.

However, with such an ice production method, freezing of water in the ice tray during ice production proceeds from the contact surface between the ice tray and water and the contact surface between cold air and water to the central portion. Therefore, gas components and impurities dissolved in water are confined in the center of the ice, and as a result, the center becomes cloudy and becomes opaque ice, which is organoleptically suitable for drinks such as whiskey. It wasn't what it was.

Therefore, there has been a need for transparent ice from the past, and devices for producing it have been described, for example, in FIGS.
The method shown in the figure is considered. The contents will be described below with reference to the drawings.

Reference numeral 1 denotes a refrigerator main body, which is divided by a partition wall 2 into a freezer compartment 3 at an upper portion and a refrigerating compartment 4 at a lower portion. 5 is a cooler for the refrigeration cycle, 6 is a blower for forced ventilation, and each is the freezing chamber 3
Is located on the back of. Reference numeral 7 denotes an ice making device arranged at the bottom of the freezing chamber 3, which comprises a first ice making chamber 8 for producing transparent ice on the upper stage of the box 7a and a first ice making chamber for producing normal ice on the lower stage. Two ice making chambers 9 are provided. The outer wall of the first ice making chamber 8 excluding the bottom surface and the front surface is surrounded by a heat insulating material 10, and a heating plate 12 made of aluminum having a heater 11 arranged on the back surface is provided on the top surface and an aluminum plate is provided on the bottom surface. Cooling plates 13 made of aluminum are respectively arranged. Reference numeral 14 is an air passage formed below the cooling plate 13, and reference numerals 15 and 16 are a first ice tray and a second ice tray housed in the first ice making chamber 8 and the second ice making chamber 9, respectively. Is. Reference numeral 17 denotes a discharge duct for forcing the cool air cooled by the cooler 5 to the ice making device 7 by the blower 6, and a discharge port 18 formed at the lower end of the discharge duct 17 and the second passage 14 respectively. It communicates with the inside of the ice making chamber 9. Reference numeral 19 is a return duct for returning the cold air discharged into the freezer compartment 3 to the cooler 5, and 20 is an ice making switch for starting transparent ice making. Further, reference numeral 21 is a refrigeration cycle compressor installed in the lower rear part of the main body 1.

Next, the electric circuit will be described. The blower 6 and the compressor 21 are connected in parallel, connected in series with the relay contact 22, and then connected to the power supply. The heater 11 has a relay contact 23
Is connected in series and then connected to the power supply.

Reference numeral 24 denotes a freezer compartment temperature control device, which is provided with a temperature sensor 25 provided in the freezer compartment 3, resistors R ₁ , R ₂ , and R ₃ , a comparison circuit including a comparator 26, a transistor 27, and a relay coil 28. , The output of the comparator 26 is the transistor
Connected to 27 bases. In addition, the transistor 27
A relay coil 28 for suction that opens and closes the relay contact 22 is connected to the collector of the. Reference numeral 29 is an ice making control device, which comprises the ice making switch 20, the timer 30, and the transistor 3
1, equipped with a relay coil 32, the ice making switch 20
The output of is connected to the input of the timer 30
The output of is connected to the base of the transistor 31. To the collector of the transistor 31, a suction relay coil 32 for opening and closing the relay contact 23 is connected. Here, the timer 30 is configured to output the "H" signal continuously for a predetermined time (t ₀ ) once a High signal (hereinafter referred to as "H") is input to the input.

In such a configuration, when the temperature of the freezer compartment 3 is higher than the predetermined value, the resistance value R _TH of the temperature sensor 25 is sufficiently small and the output of the comparator 26 is “H”, so the transistor 27 is turned on and the relay coil is turned on. 28 conducts. Then, the relay contact 22 is closed, the compressor 21 is operated, and the cooler 5 performs a cooling action. At the same time, the blower 6 is operated and the cool air cooled by the cooler 5 is forcibly ventilated into the freezing compartment 3 and the refrigerating compartment 4 and is also supplied to the ice making device 7 through the discharge duct 17 and the discharge port 18. When the cool air that has flowed into the ice making device 7 passes through the ventilation passage 14, it cools mainly the water surface of the second ice tray 16 that is stored in the second ice making chamber 9 to cool normal ice. The cooling plate 13 forming the lower surface of the first ice making chamber 8 is cooled and the cooling plate 13 is cooled. The cool air that has passed through the ventilation passage 14 is returned to the cooler 5 through the return duct 19 together with the cool air that has convected inside the freezer compartment 3.
After that, if the freezer compartment 3 is cooled to a predetermined temperature, the resistance value R _TH of the temperature sensor 25 becomes large, and the comparator 26 becomes L
Generates an ow signal (hereinafter referred to as "L"). For this reason, the transistor 27 is turned off, the conduction to the relay coil 28 is cut off, the relay contact 22 is opened, and the compressor 21 and the blower 6 are stopped. Thereafter, this operation is repeated to perform a normal cooling operation, and the cooling plate 13 of the first ice making chamber 8 is sufficiently cooled and maintained. In this state, when the user stores the first ice tray 15 filled with water to make transparent ice in the first ice making chamber 8 and at the same time turns on the ice making switch 20, the "H" signal is output. Is input to the timer 30. Timer 30 at the same time
Outputs the "H" signal continuously for a predetermined time (t ₀ ), the transistor 31 continues to be turned on during this time, the relay coil 32 becomes conductive, the relay contact 23 is closed, and the heater 11 is energized. It Then, after (t ₀ ), the output of the timer 30 is “L”.
Then, the transistor 31 is turned off, the conduction to the relay coil 32 is cut off, the relay contact 23 is opened, and the energization to the heater 11 is completed. This ice making process will be described with reference to FIG. 8. For example, when the first ice tray 15 filled with water at 30 ° C. is housed in the first ice making chamber and the ice making switch 20 is turned on, it is already cooled. The cooling action of the cooling plate 13 starts cooling from the lower surface of the first ice tray 15, and at the same time, the heating action of the heating plate 12 starts from the upper surface of the first ice tray 15 when the heater 11 is energized. Therefore, the water is gradually cooled until it reaches 0 ° C. over a period of time (t ₁ ). During this time, the compressor 21 and the blower 6 are in the freezer 3
The cycle of operation and stop is repeated depending on the temperature state of the temperature sensor 25 inside. Next, the water reaching 0 ° C. is gradually frozen in one direction from below to above by the cooling action from the cooling plate 13 on the lower surface so that the water surface is not frozen first by the heating action from the upper heating plate. Then, when the time (t ₂ ) elapses, the gas component contained in the water is released from the water surface, reaches about -5 ° C with almost no bubbles, and transparent ice is generated. Then, after a lapse of some time, when (t ₂ ) is reached from the start of ice making, the heater 11 is turned off and the heating action from the heating plate 12 is finished. Then, only by the cooling action from the cooling plate 13, the temperature is cooled to the vicinity of the temperature (for example, −20 ° C.) in the freezer compartment 3, and at this point, the ice making that can be used is completed. In addition, the time required to complete the ice making from about -5 ℃ to -20 ℃ is (t ₃ )
The ice making is completed in the total time (t) in combination with the above-mentioned times (t ₁ ) and (t ₂ ).

Problems to be Solved by the Invention However, the above-mentioned conventional example has the following problems.

(1) At the same time when the ice making switch 20 is turned on, that is, when the heater 11 is energized from the start of ice making when the first ice making tray 15 filled with water is stored, the water reaches 0 ° C. and freezes. During the so-called water state until the start of heating, the heating action of the heater 11 is performed from the upper surface, so the time to reach 0 ° C. becomes long. Further, during this time, the compressor 21 and the blower 6 are operated and stopped depending on the temperature state of the temperature sensor 25 in the freezer compartment 3, so that the cooling plate 13 is not actively cooled at the time of the stop, and it takes a long time to reach 0 ° C. become. Next, even after the heater 11 is turned off, the compressor 21 and the blower 6 are cooled to a temperature close to that of the freezer compartment 3 while operating and stopping according to the state of the temperature sensor 25, which also increases the cooling time. Therefore, the total ice making time from the start of ice making to the completion of ice making becomes long.

(2) When the heater 11 is continuously energized and a constant heating amount is given from the heating plate 12 regardless of whether the compressor 22 and the blower 6 are operating or stopped, when the outside air temperature is relatively low, for example, the outside air temperature. In the case of 10 ° C., if the heat load on the refrigerator body 1 is reduced, the operating time of the compressor 22 and the blower 6 is reduced, and the cooling amount of the cooling plate 13 is reduced, the balance with the heating amount of the heating plate 12 is lost. . That is, the heating amount is relatively increased, and the progress of ice making is delayed more than necessary. For this reason, when the heater 11 is de-energized, ice making is not finished even when th has passed, and when the heater 11 is de-energized while the water condition remains, the relative cooling amount rapidly rises and the water surface There was a problem that the ice became cloudy due to freezing from the vicinity, and the ice did not become transparent. Also, in order to avoid this, if the energization time th of the heater 11 by the ice making switch 20 is set long in advance with a sufficient margin, the problem that cloudy ice will be formed at low outside temperature is solved, but ice making We cannot solve the inconvenience that the end time becomes longer than necessary. As described above, according to the above-described example, when the temperature of the refrigerator body 1 is changed when the door is opened or closed or the food load is turned on, such as the outside air temperature, it cannot be dealt with each time and it is opaque depending on one condition. Ice was sometimes generated.

The present invention is to solve the above-mentioned problems, and an object thereof is to provide an ice-making device capable of stably and efficiently producing transparent ice even when a heat load condition of a main body of a refrigerator or the like changes. There is.

Means for Solving the Problems In order to solve the above problems, an ice making device such as a refrigerator of the present invention has a first cooling period in which the heating means is stopped and the cooling means is continuously operated after the ice making switch is turned on, The first
Second cooling period in which the heating means is operated when the cooling means is operating subsequent to the cooling period or when the water temperature sensor for indirectly detecting the water temperature becomes equal to or lower than a predetermined temperature, and the second cooling It is provided with an ice making control device configured in a third cooling period in which the heating unit is stopped and the cooling unit is continuously operated after the period.

Operation According to the above-described configuration of the present invention, (1) the water is rapidly cooled by continuously receiving only the cooling action from the cooling plate in the first cooling period until the temperature reaches 0 ° C.

Also during the third cooling period when the freezing is completed, it is similarly rapidly cooled to produce hard ice.

(2) During the second cooling period in which the freezing is progressing, the heating means such as the heater is basically operated in synchronization with the operation of the cooling means, so that the cooling and the heating are balanced, and the ice making is the lower surface at a predetermined freezing rate. Proceed to the upper surface. Also, when the cooling means does not operate for a long time, the heating means does not operate, and when the temperature of the water temperature sensor falls below a predetermined temperature, the heating means operates and the heating means does not operate for a long time and the water surface freezes first. There is no.

EXAMPLE An ice making device such as a refrigerator according to an example of the present invention will be described below with reference to FIGS. The same components as those of the conventional one are designated by the same reference numerals, and detailed description thereof will be omitted. 33
Is an ice making device provided in the lower part of the freezer compartment 3, and a water temperature sensor
35 is attached to the back space of the heating plate 12 by the support piece 34. 36 is a freezer compartment temperature control device, which is a temperature sensor 25,
A comparison circuit including resistors R ₁ , R ₂ , R ₃ and a comparator 26, an OR circuit 37, a transistor 27, and a relay coil 28,
The output of the comparator 26 is connected to one input of the OR circuit 37, and the output of the OR circuit 37 is connected to the base of the transistor 27. A suction coil relay 28 for opening and closing the relay contact 22 is connected to the collector of the transistor 27.

38 is a water temperature detection circuit, which is a water temperature sensor 35, resistors R ₄ , R ₅ , R ₆ ,
It is provided with a comparison circuit including a comparator 39 and an OR circuit 40, and outputs of the comparators 26 and 39 are connected to inputs of the OR circuit 40.

41 is an ice making control device, which is an ice making switch 20, a timer 42,
It is provided with a transistor 31 and an AND circuit 43. The output of the ice making switch 20 is connected to the input of the timer 42. The output of the b terminal of the timer 42 and the output of the OR circuit 40 are connected to the input of the AND circuit 43. here,
Once the "H" signal is input, the timer 42 outputs the "H" signal from the a terminal for a predetermined time (t ₁ '), and then the "H" signal from the b terminal for the predetermined time (t ₂ '). Is output, and finally, the "H" signal is output from the a terminal again until the set time (t ') until the completion of ice making is reached. Next, the output of the a terminal of the timer 37 is connected to the other input of the OR circuit 37 of the freezer compartment temperature control device 36, and the output of the AND circuit 43 is connected to the base of the transistor 31. . A collector relay coil 32 for opening and closing the relay contact 23 is connected to the collector of the transistor 31.

In such a configuration, when the user turns on the ice making switch 20, the "H" signal is input to the input of the timer 42 (t ₁ ′).
Since the "H" signal is output from the a terminal during the period, one input of the OR circuit 37 becomes "H" and the output becomes "H" regardless of the other input. Therefore, the transistor 27 is turned on, the relay coil 28 is conducted, the relay contact 22 is closed, and the compressor 21 and the blower 6 are continuously operated. Then, the cooling plate 13 of the first ice making chamber 8 is continuously cooled by the cold air flowing through the ventilation passage 14. Further, during this period, the b terminal output of the timer 42 is "L", so the transistor 31 is OFF, that is, the heater 11 is OFF, there is no heating action from the heating plate 12, and the water in the first ice tray 15 is 0. It cools rapidly toward 0 ° C. and reaches 0 ° C. in a short time (ie t ₁ ′ <t ₁ ).

Next, when the time (t ₁ ′) elapses, the output of the timer 42 is “H” from the terminal b for the time (t ₂ ′). Then, the relay coil 32 is conducted, the relay contact is closed, and the heater 11 is turned on. That is, if the comparator 26 is "H" (the compressor 21 is operating and cooling) or the comparator 39 is "H" (the temperature of the water temperature sensor is lower than the set value T ₁ ), the heater 11 is energized. Become. That is, basically when the cooling plate is being cooled, heating is performed from the water surface, and the operating rate of the compressor 21 changes due to changes in the outside air temperature, opening and closing of the door in the actual use, input of food load, etc. Even if the cooling amount changes, the amount of heating is balanced in synchronism with it, and the ice making time is constant, and stable, transparent ice can be made. When the outside temperature is low (5 ° C to 0 ° C), the operation of the compressor 21 is reduced and the energization rate of the heater 11 is reduced, which may freeze the water surface.
Since 35 becomes lower than a predetermined value and the output of the comparator 39 becomes "H", the heater 11 is energized to prevent freezing of the water surface.
When (t ₂ ′) has passed, the output of timer 42 is b
The terminal is switched to the terminal a again and the "H" signal is output until the ice making completion time (t ') is reached. That is, the continuous cooling action without the above-described heating action is performed, and the temperature is rapidly cooled to near the temperature of the freezer compartment 3 (about -20 ° C) in a short time. Ie 0
° C. t ₁ to time up to the '(conventional example t _1), 0 to about -5゜Wo t ₂ ended frozen from ° C.' (eg conventional t _2), the cooling period subsequent finishing t ₃ Assuming ′ ′ (t _{3 in the} conventional example), the total ice making time t ′ = t ₁ ′ + t ₂ ′ + t ₃ ′ is much shorter than the ice making time t = t ₁ + t ₂ + t _{3 in the} conventional example.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) Since the first cooling period until the water reaches 0 ° C. and the third cooling period after the end of the heating action of the second cooling period are subjected to no heating action and continuous cooling action, respectively. During the period, the required time can be shortened, and the effect that the total ice making time can be greatly shortened can be obtained.

(2) Even if there is a change in conditions such as the increase or decrease of the heat load on the main body of the refrigerator etc. due to opening / closing of the door / addition of food, the heating means is activated only when the cooling means for the ice tray is activated. When the operation of the cooling means is stopped, the operation of the heating means is also stopped, so that the balance between cooling and heating is always maintained and the time required for ice making is almost constant. Can produce ice.

(3) Even when the operating time of the cooling means is extremely short due to low outside air temperature, the water temperature sensor detects the ambient temperature on the upper surface of the ice tray to operate the heating means, and the water surface may be frozen. Absent.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of an ice making device such as a refrigerator showing an embodiment of the present invention, FIG. 2 is a characteristic diagram when the ice making device produces transparent ice, and FIG. 3 is a cross section of the ice making device. Fig. 4 is a sectional view of a refrigerator equipped with a conventional ice making device, Fig. 5 is a front view of the same ice making device, Fig. 6 is a sectional view of the same ice making device, and Fig. 7 is an electric diagram of the ice making device. The circuit diagram and FIG. 8 are characteristic diagrams when transparent ice is produced by the ice making device. 8 …… First ice making room (ice making room), 10 …… Insulation material, 11 ……
Heater (heating means), 12 ... Heating plate, 13 ... Cooling plate, 14
...... Ventilation path (cooling means), 15 ...... 1st ice tray (ice tray), 20 ... Ice making switch, 33 ... Ice making device, 35 ... Water temperature sensor, 41 ... Ice making control device.

Claims (1)

[Claims] 1. A cooling plate, cooling means for cooling the cooling plate, an ice making chamber having the cooling plate as a bottom face and an opening in the front face, and an ice making chamber formed in the ice making chamber and placed on the cooling plate. Mounted ice tray, heating plate provided with heating means provided on the upper surface of the ice tray, heat insulating material arranged in the outer wall excluding the bottom surface and front surface of the ice making chamber, and attached to the back surface of the heating plate A water temperature sensor that indirectly detects the ambient temperature of the upper surface of the ice making tray, an ice making switch that commands the start of ice making, and the heating means is stopped after the ice making switch is turned on to continuously operate the cooling means. 1 cooling period and the first
A second cooling period in which the heating unit is operated when the cooling unit is operating or the water temperature sensor is below a predetermined temperature following the cooling period of An ice making device such as a refrigerator provided with an ice making control device configured in a third cooling period in which the heating means is stopped and the cooling means is continuously operated.