JPH05306860A - Automatic ice making device - Google Patents

Abstract

PURPOSE:To make it possible to detect accurately two cases when water is supplied and no water is supplied by completing the supply of water when the temperature in an ice making pan exceeds a specified temperature in a fixed time after having started water supply operation. CONSTITUTION:An ice making pan is assumed to have finished ice separation and returned to a horizontal position from a fulcrum position. Then, a return signal is output from a switch circuit 25 while control device 25 reads a detection temperature of an ice making pan temperature sensor 19 and starts the operation of a water supply pump 18 so as to supply water to the ice making pan. In this case, the amount of water supply is controlled by the drive continuous time of the water supply pump 18 where the control device 25 halts the operation of the water supply pump 18 when a fixed time passes from the start of water supply. After the pump 18 is suspended, the control device 25 determines whether or not the fixed time has passed since the starting point of water supply operation and reads the detected temperature of the ice making pan temperature sensor 19. The control device 25 further tries to compute the difference between the detection temperature directly prior to the starting point of water supply and the detection temperature available after the lapse of the fixed time and determines whether or not the difference exceeds a specified value and ends water supply if it exceeds the specified value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic ice-making machine that automatically performs water supply to an ice tray and ice-free after the ice-making is completed.

[0002]

2. Description of the Related Art Conventionally, refrigerators provided with an automatic ice making device have been provided. This automatic ice making device sequentially executes a series of steps relating to the automatic ice making by the control device, and the user can obtain the ice only by supplying water to the water supply tank in the refrigerating compartment.

That is, the refrigerator is provided with an ice making chamber to which cold air is supplied from a cooler. An ice tray connected to the motor is provided in the ice making chamber, and the control device first drives the pre-water supply pump to supply a certain amount of water from the water supply tank to the ice tray. The water stored in the ice tray is cooled by the cold air supplied to the ice making chamber to become ice. When ice making is completed, the control device drives the motor to turn the ice tray upside down and twist it. As a result, the ice in the ice tray is released and falls, and is stored in the ice storage container.

In this automatic ice making device, a temperature sensor is attached to the bottom of the ice tray, and the control device determines whether or not water is actually supplied to the ice tray according to the temperature detected by the temperature sensor, and the ice making is completed. I try to judge whether or not I did.

That is, when the ice making is completed, the ice making tray becomes extremely low temperature. Further, when water is supplied to the ice tray after the ice is released, the ice tray that had been at an extremely low temperature until then is warmed by the water and its temperature rises. So, for example, the temperature of the ice tray is -1
When the temperature becomes 3.5 ° C or lower, ice making is completed, and the temperature of the ice tray at the time of 12 minutes after the water supply operation of the water supply pump is -9.
When the temperature is 5 ° C. or higher, it is determined that water is actually supplied to the ice tray.

When the temperature of the ice tray at 12 minutes after the water supply operation of the water supply pump is below -9.5 ° C, the water supply tank is empty and water is not supplied. I am trying to display that by a lamp.

[0007]

However, in the above-mentioned conventional structure, the water supply tank is empty and water is not actually supplied to the ice tray even when the water supply pump performs the water supply operation. However, if the door of the ice making chamber is left open for a long time to remove the ice from the ice storage container, the temperature of the ice making tray rises to -9.5 ° C or more due to the invasion of outside air into the ice making chamber. There is. Further, when the frost adhering to the cooler is being defrosted by heating with the heater, the supply of cold air to the ice making chamber is stopped during that time, so that the temperature of the ice tray may rise to -9.5 ° C or higher. is there.

In such a case, the control device detects that the water supply is completed even when the water supply tank is empty and water is not actually supplied to the ice tray. As a result, the water supply tank is left empty, which causes a problem that ice is not stored in the ice storage container when it is desired to take out the ice.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an automatic ice making device capable of accurately detecting when water is actually supplied to an ice tray and when water is not actually supplied. To provide.

[0010]

In order to achieve the above object, the present invention is directed to the temperature of the ice tray after the completion of water supply to the ice tray receiving the supply of cold air is detected by the water supply completion detecting means. In an automatic ice making device that executes an ice removing operation of dropping ice from the ice tray when the temperature has dropped to, the water supply completion detecting means, after the water supply operation, when the temperature of the ice tray rises above a predetermined temperature within a certain period of time, It is characterized by the completion of water supply.

[0011]

When the water is actually supplied to the ice tray, the temperature rise of the ice tray is larger than when the door is opened or the cooler is in the defrosting state. Therefore, after the water supply operation, when the temperature of the ice tray rises above a predetermined temperature within a certain period of time, by completing the water supply, it can be accurately determined that the ice tray is actually supplied with water.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings by applying it to an automatic ice making device provided in a fan-cool type refrigerator.

First, in FIG. 3, a freezer compartment 2, a refrigerating compartment 3 and an ice making compartment 4 are formed inside a refrigerator main body 1, and air cooled by a cooler 5 is distributed to each of these compartments by a fan 6. It is being supplied. A defrosting heater 7 for removing frost attached to the cooler 5 is provided below the cooler 5. An automatic ice making device 8 according to the present invention is provided in the ice making chamber 4, and the automatic ice making device 8 will be described in detail below with reference to FIGS. 1 and 2.

That is, a machine body 9 is provided on the upper front side in the ice making chamber 4, and a gear reduction mechanism (not shown) driven by a motor 10 (see FIG. 4) is housed in the machine body 9. Has been done. A support frame 11 is provided on the rear side of the machine body 9, and an ice tray 12 is arranged inside the support frame 11. This ice tray 12 has a shaft 1 at the rear center.
It is rotatably supported by the support frame 11 via 2a, and the front center part is connected to the output shaft of the gear reduction mechanism.
Then, when the motor 10 rotates in the forward or reverse direction, the ice tray 12 is turned upside down or returned from the inverted position to the original horizontal position.

Although not shown, a projection is provided on the rear portion of the ice tray 12 so that the projection abuts the support frame 11 just before the end of the reversing operation. The motor 10 continues to rotate for a while even after the protrusion comes into contact with the support frame 11 to rotate the front portion of the ice tray 12 to the normal reversal position, so that the ice tray 12 is twisted and the ice is rotated by this twist. Is separated from the ice tray 12 and dropped and stored in the ice storage container 13 below.

Water is supplied to the ice tray 12 by a water supply device 14. This water supply device 14
Is a water supply tank 15 arranged in the refrigerating chamber 3, a water receiving tray 16 for receiving water from the water supplying tank 15, and the water receiving tray 1
It is composed of a water supply pump 18 that pumps the water in 6 into the ice tray 12 through a water supply pipe 17. An ice tray temperature sensor 19 that detects the temperature of the bottom is attached to the bottom of the ice tray 12.

On the other hand, in the rear wall of the ice making chamber 4, there is provided a cool air duct 20 for guiding the cool air sent by the fan 6 into the ice making chamber 4. The outlet 20a of the cold air duct 20 is directed obliquely upward, and the cold air discharged from the outlet 20a is blown onto the lower surface of the ice tray 12. Further, in order to prevent the cool air discharged from the outlet 20a from wrapping around to the upper surface side of the water stored in the ice tray 12, a lid 21 made of a heat insulating material covering the upper surface of the ice tray 12 is rotatable. It is installed in.

Inside the lid 21, a heater 22 for heating the ice tray 12 from above and a lid temperature sensor 23 for detecting the ambient temperature of the upper portion of the ice tray 12 heated by the heater 22 are provided. .. The lid 21 is supported by a support rod 24 as shown by the chain double-dashed line in FIG. 1 during the reversing operation of the ice tray 12 so as not to interfere with the falling of ice.

FIG. 4 is a block diagram showing a control configuration of the automatic ice making device 8. In the figure, the control device 25 is configured to include a microcomputer. A signal from a switch circuit 26 for detecting the inverted position and the horizontal position of the ice tray temperature sensor 19, the lid temperature sensor 23, and the ice tray 12 is input to the control device 25. Then, the control device 25, based on those input signals and the control program stored in advance, the motor 10 of the gear reduction mechanism, the water supply pump 18, the heater 22, the water supply tank 1
It controls a lamp 27 indicating that 5 is empty.

Next, with reference to the flow chart shown in FIG. 5, focusing on the control contents of the control device 25 relating to ice making, particularly the portion functioning as a water supply completion detecting means for detecting the completion of water supply to the ice tray 12. Explained.

Now, it is assumed that the ice tray 12 has finished ice removal and has returned from the inversion position to the horizontal position. Then, the switch circuit 2
A return signal is output from the control device 6, and the control device 25
First, the temperature T1 detected by the ice tray temperature sensor 19 is read (step S1), and then the water supply pump 18 is activated to supply water to the ice tray 12 (step S2). In this case, the amount of water supplied to the ice tray 12 is controlled by the drive continuation time of the water supply pump 18, and the control device 25 stops the water supply pump 18 at a certain time point after a certain time has elapsed from the start of water supply. ..

After that, the control device 25 shifts to step S3 for judging whether or not a predetermined time, for example, 5.5 minutes, has elapsed from the start of water supply, and when the same time has elapsed ("YES" in step S3), Next, the temperature T2 detected by the ice tray temperature sensor 19 is read (step S4). Then, the control device 25 calculates the difference ΔT between the detected temperature T1 immediately before the start of water supply and the detected temperature T2 after 5.5 minutes have elapsed (step S5
), And then it is judged whether or not the difference ΔT is equal to or more than a predetermined value (step S6; water supply completion detecting means).

By the way, when water is actually supplied to the ice tray 12 by the water supply operation of the water supply pump 18 in step S2, the ice tray 12 is warmed by water and its temperature gradually rises. At this time, ice tray 12
Since the water supplied to the water was the water stored in the water tray 16 in the refrigerating compartment 3 until then, considering that the temperature in the refrigerating compartment 3 is usually around 5 ° C, the above ΔT, in other words, For example, the temperature rise within a certain period of time is quite high.

On the other hand, when the water supply tank 15 is empty, even if the water supply pump 18 performs the water supply operation, the ice tray 12
Water will not be actually supplied to. In this case, for example, if the door (not shown) of the ice making chamber 3 is left open for a long time in order to take out the ice from the ice storage container 13, the outside air enters to warm the ice making tray 12. Also,
When the cooler 5 is being defrosted by the defrosting heater 7, the compressor (not shown) is stopped and cold air is not supplied to the ice making chamber 4 during the defrosting.
The inside temperature rises naturally, and as a result, the temperature of the ice tray 12 also rises. However, in the case of the former, the outside air that has entered the ice making chamber 4 mixes with the extremely low temperature air, and in the case of the latter, a natural temperature rise due to so-called heat leakage occurs. The degree of temperature rise in 4 is not so high, and the temperature rise ΔT of the ice tray 12 within the fixed time is not so high.

As described above, there is a clear difference between the ΔT when water is actually supplied to the ice tray 12 and the ΔT when water is not actually supplied to the ice tray 12, and the difference is large or small. Thus, it is possible to clearly distinguish between the case where water is actually supplied to the ice tray 12 and the case where water is not supplied.

Now, in step S6, the controller 25 determines that the temperature rise ΔT within a fixed time is equal to or greater than a predetermined value ("Y
ES "; water was actually supplied to the ice tray 12), then the temperature T3 detected by the ice tray temperature sensor 19 is read (step S7), and the temperature T3 is equal to or lower than the ice making completion temperature of -13.5 ° C. It is repeated to determine whether or not (steps S7 and S8 are repeated).

On the other hand, as for the water supplied into the ice tray 12 as described above, the cold air discharged from the outlet 20a of the cold air duct 20 blows against the lower surface portion of the ice tray 12 to cause the ice tray 12 to cool. It is cooled from the bottom side. During this cooling, the control device 25 energizes the lid 21 to warm the water in the ice tray 12 from the upper surface side. Therefore, in addition to the cooling of the ice tray 12 from the lower surface side by the cold air, the heater 22
Heats the ice tray 12 from the upper surface side, so that water begins to freeze from the lower surface side. The heater 22 is on / off controlled based on the temperature detected by the lid temperature sensor 23 so that the upper surface side of the ice tray 12 maintains a constant temperature.

When all the water in the ice tray 12 becomes ice, the temperature of the ice tray 12 rapidly decreases, and the ice tray temperature sensor 19 detects -13.5 ° C. or lower ("YES" in step S8). )), The control device 25 determines that the ice making is completed, and causes the ice removing operation to be performed (step S9). This ice removing operation is performed by rotating the motor 10 of the gear reduction mechanism in the forward direction to turn the ice tray 12 upside down. Immediately before the end of this inversion operation, the ice tray 12 is twisted, and due to this twist, the ice is separated from the ice tray 12 and dropped and stored in the ice storage container 13.

When the ice tray 12 is rotated to the inversion position, the switch circuit 26 outputs an inversion completion signal. Therefore, the control device 25 then rotates the motor 10 in the reverse direction to move the ice tray 12 to the original position. To the horizontal position. When the ice tray 12 returns to the horizontal position, a return signal is output from the switch circuit 26, so that the control device 25 returns to step S1 to supply water to the ice tray 12.

Now, in step S6 for judging whether or not the temperature rise ΔT within the predetermined time is equal to or more than a predetermined value, Δ
When T is less than the predetermined value (“NO”; water is not actually supplied to the ice tray 12), the control device 25 lights the lamp 27 to notify that the water supply tank 15 is empty (step S10). .. When the user takes out the water supply tank 15 from the refrigerating room 3 by seeing the lighting of the lamp 27, replenishes the water in the water supply tank 15 and resets the water in the refrigerating room 3, the controller 25 sets the water supply tank 15. Step S1 based on a signal from a switch (not shown) that operates in response to
It is configured to return to and supply water.

As described above, according to this embodiment, whether or not the difference ΔT between the temperature of the ice tray 12 at the start of water supply and the temperature of the ice tray 12 at the time when a certain time has elapsed from that time is not less than a predetermined value. Therefore, it is configured to determine whether or not water is actually supplied to the ice tray 12, so that it is determined whether or not the temperature of the ice tray is equal to or higher than a predetermined temperature when a predetermined time has elapsed from the start of water supply. In contrast, it is possible to accurately determine whether the temperature rises due to water supply or the other temperature rises due to, for example, opening of the door or defrosting. For this reason,
If water supply tank 15 is empty and water has not actually been supplied, there is no risk of determining that water supply is complete, and if water supply tank 15 is empty, this is indicated by lamp 2
It can be surely notified by 7.

[0032]

As described above, according to the present invention, it is determined that the water supply is completed when the temperature of the ice tray rises above a predetermined temperature within a certain time after the water supply operation. The temperature rise can be accurately discriminated between the case where water is actually supplied and the case other than that, for example, when the door is opened or during defrosting, and water is not supplied to the ice tray. Nevertheless, it has an excellent effect that it is possible to surely prevent the problem that it is determined that the water supply is completed.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of an essential part showing an embodiment of the present invention.

[Figure 2] Front view of the same section

FIG. 3 is a vertical cross-sectional side view of the refrigerator shown partially removed.

FIG. 4 is a block diagram showing an electrical configuration.

FIG. 5 is a flowchart showing the control contents regarding ice making.

[Explanation of symbols]

3 is an ice making chamber, 12 is an ice tray, 14 is a water supply device, 15 is a water supply tank, 19 is an ice tray temperature sensor, 20 is a cold air duct, 21 is a lid, 22 is a heater, 23 is a lid temperature sensor,
25 control device (water supply completion detecting means).

Claims (1)

[Claims] 1. A deicing operation for dropping ice from the ice tray when the temperature of the ice tray drops to a set temperature after the completion of water supply to the ice tray receiving cold air is detected by the water supply completion detecting means. In the automatic ice making device to be executed, the water supply completion detecting means completes the water supply when the temperature of the ice tray rises above a predetermined temperature within a certain time after the water supply operation.