US20110023502A1

US20110023502A1 - Automatic icemaker

Info

Publication number: US20110023502A1
Application number: US12/899,388
Authority: US
Inventors: Hideaki Ito; Naotaka Sasaki; Kenji Sugaya
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-04-04
Filing date: 2010-10-06
Publication date: 2011-02-03
Also published as: US20070227164A1; JP2007278548A; JP4224573B2

Abstract

An automatic icemaker according to the present invention is capable of being installed in a freezing compartment and automatically making and discharging ice cubes, the automatic ice-making comprising at least one ice-making tray having a plurality of small ice-making compartments, partitions disposed between respective adjacent small ice-making compartments, and groove-shaped water-passage channels formed in portions of the partitions which are offset from centers of the partitions, and a rotating device for rotating the ice-making tray, wherein water is supplied after the ice-making tray is inclined at a water supply angle less than a water filling angle in such a direction that the water passage channels face downward.

Description

This application is a Divisional of co-pending application Ser. No. 11/724,254 filed on Mar. 15, 2007, which claims priority to Application No. 2006-102649 filed in Japan on Apr. 4, 2006. The entire contents of all of the above applications are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to an automatic icemaker which is provided in a refrigerator, and designed such that it repeatedly carries out a water feeding operation, an ice making operation and an ice discharging operation according to a predetermined sequence, and automatically makes ice cubes.
2. Description of the Prior Art
In a conventional automatic icemaker, a groove-shaped water-passage channels are formed in partitions between respective adjacent small ice-making compartments of an ice-making tray in order that water supplied to the ice-making tray from above the ice-making tray can be equally spread into respective small ice-making compartments of the ice-making tray. However, when ice cubes formed in the small ice-making compartments are to be discharged from the ice-making tray, adjacent ice cubes in the small ice-making compartments are freezingly connected to each other through ice formed in the water passage channels. This contributes to falling of the dischargeability of the ice cubes and users' convenience.
For this reason, it is conceivable that the groove-shaped water passage channels are formed in portions of the partitions between the respective adjacent small ice-making compartments which are offset from centers of the partitions, and the ice-making tray is inclined at a predetermined angle, which allows the water to be equally spread into the respective small ice-making compartments, namely, at a water filling angle, and the supply of the water to the ice-making tray is then carried out.
However, when the supply of the water is carried out in the condition where the ice-making tray is inclined at the water filling angle, the water runs along walls of the small ice-making compartments and spills out of the ice-making tray.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an automatic icemaker which is capable of causing water supplied to an ice-making tray from above the ice-making tray to be equally spread into respective small ice-making compartments of the ice-making tray, does not allow adjacent ice cubes formed in the small ice-making compartments to be freezingly connected to each other through ice formed in water passage channels when the ice cubes are to be discharged from the ice-making tray, and does not allow the water to spill out of the ice-making tray at the time of the water supply.
In accordance with one aspect of the present invention, there is provided an automatic icemaker which is capable of being installed in a freezing compartment and automatically making and discharging ice cubes, the automatic icemaker comprising at least one ice-making tray having a plurality of small ice-making compartments, partitions disposed between respective adjacent small ice-making compartments, and groove-shaped water-passage channels formed in portions of the partitions which are offset from centers of the partitions, and a rotating device for rotating the ice-making tray, wherein water is supplied after the ice-making tray is inclined at a water supply angle less than a water filling angle in such a direction that the water passage channels face downward.
According to an another aspect of the present invention, there is provided an automatic icemaker which is capable of being installed in a freezing compartment and automatically making and discharging ice cubes, the automatic icemaker comprising at least one ice-making tray having a plurality of small ice-making compartments, partitions disposed between respective adjacent small ice-making compartments, and groove-shaped water-passage channels formed in portions of the partitions which are offset from centers of the partitions, and a rotating device for rotating the ice-making tray, wherein water is supplied while the ice-making tray is rotated in such a direction that the water-passage channels face downward, according to a quantity of the water stored in the small ice-making compartments by the supply of the water.
In these automatic icemakers, the groove-shaped water-passage channels are formed in the portions of the partitions between the respective small ice-making compartments which are offset from the centers of the partitions, so that the water can be equally spread into the respective small ice-making compartments and adjacent ice cubes formed in the small ice-making compartments are not freezingly connected to one another through ice formed in the water passage channels when the ice cubes are to be discharged from the ice-making tray. Moreover, the ice-making tray is inclined at the water supply angle in such a direction that the water passage channels face downward, and the supply of the water to the ice-making tray is then carried out, or the supply of the water is carried out while causing the ice-making tray to be rotated in such a direction that the water passage channels face downward, according to the quantity of the water stored in the small ice-making compartments by the supply of the water, so that even if the flow of the water is strong, it is possible to supply the water to the ice-making tray without allowing the water to spill out of the ice-making tray.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view of an automatic icemaker according to an embodiment of the present invention;

FIG. 2 is a schematic front sectional view of the automatic icemaker shown in FIG. 1;

FIG. 3 is a schematic enlarged sectional view of the automatic icemaker, taken along a line A-A in FIG. 1;

FIG. 4 is a system block diagram of the automatic icemaker shown in FIGS. 1 to 3;

FIG. 5 is a functional block diagram of a microprocessor of the automatic icemaker shown in FIGS. 1 to 4;

FIG. 6 is a flow chart which is of assistance in explaining the operation of the automatic icemaker shown in FIGS. 1 to 4;

FIGS. 7A, 7B and 7C are each a view which is assistance in explaining the operation of the automatic icemaker shown in FIGS. 1 to 4;

FIG. 8 is a functional block diagram of a microprocessor of an automatic icemaker according to another embodiment of the present invention; and

FIG. 9 is a flow chart which is of assistance in explaining the operation of the automatic icemaker having the microprocessor, the functional block of which is illustrated in FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 to 4, an automatic icemaker according to an embodiment of the present invention will be discussed hereinafter. An ice-making tray 4 is rotatably attached to a control box 2. A reversible motor 6 is provided in the control box 2. A pinion gear 8 is mounted on an output shaft of the motor 6. A driven gear 10 is mounted on a shaft of the ice-making tray 4. The pinion gear 8 and the driven gear 10 are meshed with each other. The motor 6, the pinion gear 8 and the driven gear 10 constitute a rotating device for rotating the ice-making tray 4. A water supply port 12 is provided above the ice-making tray 4. A water supply solenoid valve 14 for opening and closing the water supply port 12 is provided at the water supply port 12. The ice-making tray 4 is provided with a plurality of small ice-making compartments 16 which are lined up along the direction of a rotation centerline of the ice-making tray 4. Groove-shaped water-passage channels 20 are formed in portions of partitions 18 between respective adjacent small ice-making compartments 16, which are offset from centers of the partitions 18, namely, in end portions of the partitions 18. An ice-fullness detecting arm 26 is rotatably provided at the control box 2 and adapted to be driven by the motor 6. Incidentally, a mechanism for transmitting the power of the motor 6 to the ice-fullness detecting arm 26 is not shown.
A microprocessor 28 containing an AD converter and a counter is provided in the control box 2. A temperature detecting sensor 22 is designed such that it successively outputs a temperature signal voltage corresponding to a temperature of the ice-making tray 4. A position detecting sensor 24 is designed such that it outputs a position signal voltage corresponding to a rotational position of the ice-making tray 4. An ice-fullness detecting sensor 30 is designed such that it outputs a signal voltage corresponding to amounts of ice cubes stored in an ice storage box (not shown), according to the movement of the ice-fullness detecting arm 26. A motor drive circuit 32 is designed such that it drives the motor 6. A valve drive circuit 34 is designed such that it drives the water supply solenoid valve 14. The microprocessor 28 is designed such that it gradually inputs the temperature signal voltage outputted from the temperature detecting sensor 22, and carries out an AD conversion, to thereby detect the temperature of the ice-making tray 4. Also, the microprocessor 28 is designed such that it detects from the signal voltage from the position detecting sensor 24 that the ice-making tray 4 is in a horizontal position with an opening portion of the ice-making tray 4 facing the water supply port 12. Moreover, the microprocessor 28 is designed such that it receives the signal voltage from the ice-fullness detecting sensor 30 and then detects that predetermined amounts of ice cubes have been stored in the ice storage box. Furthermore, the microprocessor 28 is designed such that it controls the motor drive circuit 32 and the valve drive circuit 34.
This automatic icemaker is fixed through a bracket (not shown) to a fixing part which is provided in advance in a freezing compartment of a refrigerator. In the automatic icemaker, water supplied to the ice-making tray 4 from the water supply port 12 is frozen by the cold in an interior of the freezing compartment, and the ice-making tray 4 is rotated by the motor 6, whereby formed ice cubes are released and discharged from the ice-making tray 4, and the discharged ice cubes are adapted to be dropped into the ice storage box. Moreover, a temperature detecting sensor (not shown) for detecting the temperature of the interior of the freezing compartment is provided and adapted to successively detect the temperature of the interior of the freezing compartment.
FIG. 5 is a functional block diagram of the microprocessor of the automatic icemaker shown in FIGS. 1 to 4. A water supply angle inclination instructing-means 38 controls the motor drive circuit 32 when a cycle of making ice is started, and then causes the ice-making tray 4 to be inclined at an angle equivalent to 20-30% of a water filling angle, namely, at the water supply angle. A valve opening instructing-means 40 controls the valve drive circuit 34 after the water supply angle inclination instructing-mean 38 causes the ice-making tray 4 to be inclined at the water supply angle, and then causes the water supply solenoid valve 14 to be opened. After a predetermined time has elapsed since the valve opening instructing-means 40 causes the water supply solenoid valve 14 to be opened, a valve closing instructing-means 42 controls the valve drive circuit 34 and then causes the water supply solenoid valve 14 to be closed. A water filling angle inclination instructing-means 44 controls the motor drive circuit 32 after the valve closing instructing-means 42 causes the water supply solenoid valve 14 to be closed, and then causes the ice-making tray 4 to be inclined at the water filling angle. After a predetermined time has elapsed since the water filling angle inclination instructing-means 44 causes the ice-making tray 4 to be inclined at the water filling angle, a horizontal position return instructing-means 46 controls the motor drive circuit 32 and then cause the ice-making tray 4 to be returned to the horizontal position.
Referring now to FIGS. 6 and 7, the operation of the automatic icemaker shown in FIGS. 1 to 4 will be discussed hereinafter. First of all, when ice-making is to be started, the microprocessor 28 confirms from the output of the position detecting sensor 24 that the ice-making tray 4 is in the horizontal position in a condition where the opening portion of the ice-making tray 4 faces the water supply port 12. At this time, unless the ice-making tray 4 is in the horizontal position, the microprocessor 28 controls the motor drive circuit 32 to drive the motor 6, whereby the ice-making tray 4 is rotated to the horizontal position. Then, when the ice-making cycle is started, the microprocessor 28 (the water supply angle inclination instructing-means 38) causes the ice-making tray 4 to be inclined at the water supply angle (S1) as shown in FIG. 7A. Then, the microprocessor 28 (the valve opening instructing-means 40) causes the water supply solenoid valve 14 to be opened (S2). Thereupon, water is supplied to the ice-making tray 4 from the water supply port 12. After a predetermined time has elapsed since the water supply solenoid valve 14 is opened, the microprocessor 28 (the valve closing instructing-means 42) causes the water supply solenoid valve 14 to be closed (S3 and S4). That is, the quantity of the water supplied to the ice-making tray 4 is managed depending on time expended during the water supply solenoid valve 14 is opened. The time which is expended during the water supply solenoid valve 14 is opened is set to time during which the surface of the water 36 supplied to the ice-making tray 4 which is in the horizontal condition does not reach bottom surfaces of the water passage channels 20. Subsequently, the microprocessor 28 (the water filling angle inclination instructing-means 44) causes the ice-making tray 4 to be inclined at the water filling angle (S5) as shown in FIG. 7B. Then, the water 36 stored in the ice-making tray 4 passes through the water passage channels 20 and is then spread evenly into the respective small ice-making compartments 16. Subsequently, after a predetermined time has elapsed since the ice-making tray 4 is inclined at the water filling angle, the microprocessor 28 (the horizontal position return instructing-means 46) causes the ice-making tray 4 to be returned to the horizontal position (S6 and S7) as shown in FIG. 7C.
Subsequently, when the microprocessor 28 detects from the output of the position detecting sensor 24 that the ice-making tray 4 is in the horizontal position, the microprocessor 28 detects the temperature of the ice-making tray 4 from the output of the temperature detecting sensor 22, and stands by until a predetermined time elapses in a condition where the temperature of the ice-making tray 4 becomes a temperature less than a preset temperature. Then, the water supplied to the respective small ice-making compartments 16 is cooled by the cold in the freezing compartment of the refrigerator and then frozen. Subsequently, when the microprocessor 28 detects that a predetermined time has elapsed in the condition where the temperature of the ice-making tray 4 is lower than the preset temperature, the microprocessor 28 controls the motor drive circuit 32 to drive the motor 6, whereby the ice-making tray 4 is rotated, and formed ice cubes are released from the ice-making tray 4 by twisting of the ice-making tray 4, or the like and dropped into the ice storage box. After the respective small ice-making compartments 16 are positively emptied, the ice-making tray 4 is returned to the horizontal position.
In this way, the water supply, ice-making and discharge of the ice cubes are repeatedly carried out according to the predetermined sequence, thus automatically making ice cubes.
When this ice-making cycle is successively carried out, the ice storage box is filled with the discharged ice cubes. When the ice-fullness detecting sensor 30 detects that the amount of the ice cubes stored in the ice storage box exceeds a predetermined amount and the microprocessor 28 detects the signal from the ice-fullness detecting sensor 30, the microprocessor 28 causes the ice-making cycle to be temporarily stopped. When the microprocessor 28 detects that the amount of the ice cubes in the ice storage box becomes less than the predetermined amount by removal of the ice cubes from the ice storage box by a user, the microprocessor 28 causes the ice-making cycle to be resumed. During the above series of the ice-making cycle, the microprocessor 28 monitors the temperature detected by the temperature detecting sensor 22. When any operation such as opening of a door of the refrigerator is carried out during the operation of the automatic icemaker, whereby the temperature becomes different from an original value of the temperature, the microprocessor 28 judges the situation as an abnormality, and then carries out abnormal-situation processing which is predetermined per each stage.
In the automatic icemaker constructed as discussed above, when the supply of the water to the ice-making tray 4 is to be started, the ice-making tray 4 is adapted to be inclined at the water supply angle, so that even if the flow of the water is strong, the water can be supplied to the ice-making tray 4 without spilling out of the ice-making tray 4. Moreover, after the supply of the water to the ice-making tray 4 is completed, the ice-making tray 4 is inclined at the water filling angle, so that the water 36 can be spread evenly into the respective small ice-making compartments 16. In addition, in the condition where the ice-making tray 4 is made to become horizontal, the surface of the water 36 supplied to the small ice-making compartments 16 does not reach the bottom surfaces of the water passage channels 20, so that the waters in the respective small ice-making compartments 16 can be made to be independent from one another and, therefore, when the ice cubes are to be discharged from the ice-making tray 4, adjacent ice cubes are not freezingly connected to each other via ice formed in the water passage channels 20. Therefore, it is possible to positively cause respective ice cubes to be independent from one another, thus improving users' convenience. Moreover, the rotation of the ice-making tray 4 allows the independence of the ice cubes from one another to be realized, so that torque to be required in order to twist the ice-making tray 4 at the time of the discharge of the ice cubes can be reduced. It is unnecessary to provide a heater or the like, so that the number of parts is not increased, the ice-making tray 4 is not large-sized, and ice cubes which are uniform in size can be made.
FIG. 8 is a functional block diagram of a microprocessor of an automatic icemaker according to another embodiment of the present invention. When the ice-making cycle is started, an operation start instructing-means 52 controls the motor drive circuit 32, cause the ice-making tray 4 to be successively rotated by the motor 6 in such a direction that the water passage channels 20 face downward and, at the same time, controls the valve drive circuit 34 to cause the water supply solenoid valve 14 to be opened. After a predetermined time has elapsed since the water supply solenoid valve 14 is opened by the operation start instructing-means 52, a valve closing instructing-means 54 controls the valve drive circuit 34 and then cause the water supply solenoid valve 14 to be closed. When a tilt angle of the ice-making tray 4 reaches the water filling angle, a water filling angle inclination instructing-means 56 controls the motor drive circuit 32 and then cause the ice-making tray 4 to be kept at the water filling angle. After a predetermined time has elapsed since the water supply solenoid valve 14 is closed by the valve closing instructing-means 54 and the tilt angle of the ice-making tray 4 is kept at the water filling angle by the water filling angle inclination instructing-means 56, a horizontal position return instructing-means 58 controls the motor drive circuit 32 and then cause the ice-making tray 4 to be returned to the horizontal position.
Referring now to FIG. 9, the operation of the automatic icemaker having the microprocessor, the functional block of which is shown in FIG. 8, will be discussed hereinafter. First of all, when the ice making cycle is started, the microprocessor 28 (the operation start instructing-means 52) causes the ice-making tray 4 to be successively rotated in such a direction that the water passage channels 20 face downward and, at the same time, causes the water supply solenoid valve 14 to be opened (S1). Thereupon, the tilt angle of the ice-making tray 4 successively becomes large and, at the same time, water is supplied to the ice-making tray 4. That is, the supply of the water to the ice-making tray 4 is carried out while causing the ice-making tray 4 to be rotated in such a direction that the water passage channels 20 face downward, according to the quantity of the water stored in the small ice-making compartments 16 by the supply of the water. Then, after a predetermined time has elapsed since the water supply solenoid valve 14 is opened, the microprocessor 28 (the valve closing instructing-means 54) causes the water supply solenoid valve 14 to be closed and the microprocessor 28 (the water filling angle inclination instructing-means 56) causes the ice-making tray 4 to be kept at the water filling angle when the tilt angle of the ice-making tray 4 reaches the water filling angle (S2 to S6). Thereupon, the water 36 stored in the ice-making tray 4 passes through the water passage channels 20 and is then spread evenly into the respective small ice-making compartments 16. Then, after a predetermined time has elapsed since the water supply solenoid valve 14 is closed and the tilt angle of the ice-making tray 4 is kept at the water filling angle, the microprocessor 28 (the horizontal position return instructing-means 58) causes the ice-making tray 4 to be returned to the horizontal position (S7 and S8).
In the automatic icemaker constructed as discussed above, the supply of the water is carried out while causing the ice-making tray 4 to be rotated according to the quantity of the water stored in the small ice-making compartments by the supply of the water, so that even if the flow of the water is strong, it is possible to supply the water to the ice-making tray 4, without allowing the water to spill out of the ice-making tray 4. Moreover, the ice-making tray 4 is kept in the condition where it is inclined at the water filling angle after the supply of the water to the ice-making tray 4 is completed, so that the water can be spread evenly into the respective small ice-making compartments 16. In addition, in the same manner as in the automatic icemaker shown in FIGS. 1 to 4, adjacent ice cubes are not freezingly connected to each other via the ice formed in the water passage channels 20, when the ice cubes are to be discharged from the ice-making tray 4.
Incidentally, while the embodiments of the present invention have been described in connection with the automatic icemaker having the single ice-making tray, the present invention may be applied to an automatic icemaker having two ice-making trays combined together back-to-back, namely, two ice-making trays combined together with bottom surfaces of small ice-making compartments 16 being opposed to each other. Moreover, while the water supply angle is set to a value equivalent to 20-30% of the water filling angle in the above-mentioned embodiments, a value of the water supply angle which is less than a value of the water filling angle is sufficient. In addition, while the temperature detecting sensor 22 which is designed such that it outputs the temperature signal voltage corresponding to the temperature of the ice-making tray 4 is employed in the above-mentioned embodiments, a temperature detecting sensor which is designed such that it outputs a temperature signal voltage corresponding to the temperature of the water poured into the respective small ice-making compartments 16 of the ice-making tray 4 (or the temperature of ice), may be employed. Moreover, while in the above-mentioned embodiments, the supplied water is made to be evenly spread into the respective small ice-making compartments 16 by causing the ice-making tray 4 to be returned to the horizontal position after the predetermined time has elapsed since the ice-making tray 4 is inclined at the water filling angle, or by causing the ice-making tray 4 to be returned to the horizontal position after the predetermined time has elapsed since the water supply solenoid valve 14 is closed and the tilt angle of the ice-making tray 4 is kept at the water filling angle, the even spreading of the water into the respective small ice-making compartments 16 may be confirmed by variation in the temperature signal voltage which is detected by the temperature detecting sensor 22 provided at the ice-making tray 4. Moreover, while the microprocessor 28 having the AD converter and the counter contained therein is employed in the above-mentioned embodiments, a microprocessor having a counter contained therein and an AD converter may be employed. In addition, while in the above-mentioned embodiments, the supply of the water to the ice-making tray 4 is carried out while causing the ice-making tray 4 to be successively rotated, the supply of the water to the ice-making tray 4 may be carried out while causing the ice-making tray 4 to be rotated step by step.
The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described, or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed.

Claims

1. A method of controlling an automatic icemaker, the automatic icemaker being installed in a freezing compartment and automatically making and discharging ice cubes, the method comprising:

providing an ice-making tray having a plurality of ice-making compartments, a plurality of partitions, and a plurality of groove-shaped water-passage channels, each of the partitions being disposed between two immediately adjacent ice-making compartments, each of the groove-shaped water-passage channels passing through a corresponding one of the partitions;

rotating the ice-making tray downwardly from a horizontal position to a water supply angle;

starting supply of water to the ice-making tray only when the ice-making tray is located at the water supply angle;

stopping supply of the water to the ice-making that stays at the water supply angle when the water is supplied for a first predetermined period of time, by using the first predetermined period of time as a criteria to stop supply of the water;

after stopping supply of the water, rotating the ice-making tray further downwardly from the water supply angle to a water filling angle, such that the water in the ice-making tray that stays at the water filling angle is evenly distributed via the groove-shaped water-passage channels through the partitions to the ice-making compartments, wherein the water filling angle is larger than the water supply angle using the horizontal position of the ice-making tray as a reference point; and

rotating the ice-making tray upwardly from the water filling angle back to the horizontal position.

2. The method of claim 1, wherein no water is supplied to the ice-making tray when the ice-making tray is located at the water filling angle.

3. The method of claim 1, wherein no water is supplied to the ice-making tray except when the ice-making tray is located at the water supply angle.

4. The method of claim 1, wherein the step of rotating the ice-making tray upwardly from the water filling angle back to the horizontal position is performed when the ice-making tray stays at the water supply angle for a second predetermined period of time.

5. The method of claim 1, wherein the step of rotating the ice-making tray downwardly from the horizontal position to the water supply angle and the step rotating the ice-making tray further downwardly from the water supply angle to a water filling angle are performed by rotating the ice-making tray in a clockwise direction.

6. The method of claim 5, the step of rotating the ice-making tray upwardly from the water filling angle back to the horizontal position is performed by rotating the ice-making tray in a counterclockwise direction.

7. A method of controlling an automatic icemaker, the automatic icemaker being installed in a freezing compartment and automatically making and discharging ice cubes, the method comprising:

successively rotating the ice-making tray downwardly from a horizontal position such that a tilt angle of the ice-making tray becomes larger until the tilt angle reaches a water filling angle;

starting supply of water to the ice-making tray;

stopping supply of the water when the water is supplied for a first predetermined period of time, by using the first predetermined period of time as a criteria to stop supply of the water;

stopping rotating the ice-making tray when the tilt angle reaches the water filling angle and keeping the ice-making tray at the water filling angle such that the water in the ice-making tray that stays at the water filling angle is evenly distributed via the groove-shaped water-passage channels through the partitions to the ice-making compartments; and

rotating the ice-making tray upwardly from the water filling angle back to the horizontal position when both requirements (1) and (2) are simultaneously met for a second predetermined period of time:

(1) the ice-making tray stays at the water filling angle. and

(2) the supply of the water is stopped.

8. The method of claim 7, wherein the step of successively rotating the ice-making tray downwardly and the step of starting supply of water to the ice-making tray starts at the same time.

9. The method of claim 7, wherein the step of successively rotating the ice-making tray downwardly from the horizontal position to the water filling angle is performed by successively rotating the ice-making tray in a clockwise direction.

10. The method of claim 9, the step of rotating the ice-making tray upwardly from the water filling angle back to the horizontal position is performed by rotating the ice-making tray in a counterclockwise direction.