JPH0875330A - Refrigerator with automatic ice machine - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a refrigerator with an automatic ice maker that reliably performs ice removing operation at the time of completion of ice making without wasteful time even if there is a detection error of a temperature sensor. [Structure] The microcomputer 34 operates a first timer when the temperature detected by the temperature sensor 12 provided in the ice tray becomes equal to or lower than the ice making completion temperature of -12.5 ° C, and this timer has elapsed for 5 minutes. After that, the ice removing operation is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator with an automatic ice maker.

[0002]

2. Description of the Related Art In the conventional ice making method for a refrigerator with an automatic ice making machine, water is supplied from a water supply tank in a refrigerating compartment to an ice making tray arranged in a freezing compartment, and the ice making tray is cooled to produce ice. When ice making is completed, the ice tray is rotated to turn it upside down, and then a twist is added to remove the ice, and the resulting ice is stored in a storage container placed below the ice tray. After that, water is supplied from the water supply tank to the ice tray to automatically restart the next ice making.

The determination as to whether or not the ice making is completed is made by the temperature detected by a temperature sensor provided on the ice tray. That is, when the temperature detected by the temperature sensor becomes equal to or lower than a certain temperature, it is determined that the ice making is completed, and the ice making tray is rotated to perform the ice removing operation.

The temperature detected by the temperature sensor for this ice removing operation is optimally set at the ice making completion temperature (-10.5 ° C.), which is the temperature at which the ice making is surely completed.

However, the temperature sensor has about ± 2 ° C.
May cause a detection error. Therefore, if the set temperature is set to the ice making completion temperature (-10.5 ° C), the detected temperature is -10.5 ° C, but the actual temperature is -8.5 ° C due to the detection error. In some cases. In this case, the ice making is not completed yet, and if the ice removing operation is performed in this state, the unfinished ice including the water portion will be dropped into the storage container.

Therefore, conventionally, in consideration of this detection error, the detection temperature at which the ice removing operation is performed is set to a temperature lower than the ice making completion temperature by the detection error. That is, assuming that the detection error of the temperature sensor is ± 2 ° C, -12.5
℃ becomes the set temperature.

[0007]

By the way, when the temperature of the ice tray is from the ice making completion temperature of -10.5 ° C. to the preset temperature of -12.5 ° C., the refrigerator door is opened and closed and the surroundings of the refrigerator are closed. If the temperature is not high, a short time (eg 3
~ 4 minutes).

However, when the door of the refrigerator is opened or closed, the time required for the temperature to fall from -10.5 ° C to -12.5 ° C may be long (for example, 20 to 60 minutes). On the other hand, with ice making, even if you open and close the door,
If the temperature is lowered to 10.5 ° C, ice making is completed without requiring a long time.

Therefore, conventionally, since the detection error of the temperature sensor is taken into consideration, the ice making time may be longer than necessary as described above.

Further, in order to minimize the error of the temperature sensor, the structure around the temperature sensor has a heat insulating structure, which makes the structure complicated.

Therefore, in view of the above problems, the present invention provides a refrigerator with an automatic ice maker that surely performs the ice removing operation at the time when the ice making is completed even if there is a detection error of the temperature sensor.

[0012]

According to another aspect of the present invention, there is provided a refrigerator with an automatic ice maker, wherein a temperature sensor for detecting a temperature of an ice tray and a temperature detected by the temperature sensor are an ice making completion temperature. First temperature determination means for outputting a first temperature determination signal when the temperature becomes equal to or lower than one set temperature, and timing is activated by the first temperature determination signal of the first temperature determination means,
A first timer means for outputting a first timing completion signal when the timing of the set time is completed;
It has an ice making completion detecting means for deciding that the ice making is completed when the time counting completion signal is inputted.

A refrigerator with an automatic ice maker according to claim 2 is the refrigerator according to claim 1, wherein when the temperature detected by the temperature sensor becomes equal to or lower than a second preset temperature higher than the first preset temperature, The second temperature determination means for outputting a temperature determination signal and the second temperature determination signal of the second temperature determination means activates timekeeping, and the second time is reached when the timekeeping for the second set time longer than the first set time is completed. The second that outputs a timing complete signal
The ice making completion detecting means includes a timer means, and the ice making completion is completed when the second time counting completion signal is input from the second timer means regardless of the operating states of the first temperature determining means and the first timer means. It is what

A refrigerator with an automatic ice making machine according to a third aspect is the refrigerator according to the second aspect, wherein the ice making completion detecting means has a second temperature detected by the temperature sensor after the second timer means starts timing. When the temperature exceeds the set temperature, the second
The timer means is reset to wait for the second temperature determination signal to be input again from the second temperature determination means.

[0015]

[Operation] The operating state of the refrigerator with the automatic ice maker according to claim 1 will be described.

The first temperature determination means outputs the first temperature determination signal when the temperature detected by the temperature sensor becomes equal to or lower than the first set temperature which is the ice making completion temperature.

The first timer means starts timing from the time when the first temperature determination signal is input, and outputs the first timing completion signal when the timing of the first set time is completed.

The ice making completion detecting means determines that the ice making is completed when the first time counting completion signal is input from the first timer means.

A refrigerator with an automatic ice making machine according to claim 2 will be described.

The second temperature determination means is configured to detect the second temperature when the temperature sensor is below a second set temperature higher than the first set temperature.
Outputs the temperature judgment signal.

The second timer means starts timing from the time when the second temperature determination signal is input, and outputs the second timing completion signal when the timing of the second set time is completed.

The ice making completion detecting means judges that the ice making is completed when the second time counting completion signal is inputted from the second timer means regardless of the operating states of the first temperature judging means and the first timer means.

The operating state of the refrigerator with the automatic ice maker according to claim 3 will be described.

The ice-making completion detecting means resets the second timer means when the temperature detected by the temperature sensor becomes equal to or higher than a second set temperature after the second timer means starts counting time. , And waits for the second temperature determination signal to be input again from the second temperature determination means.

[0025]

[Embodiment] Refrigerator 1 with an automatic ice maker according to one embodiment of the present invention
Will be described with reference to FIGS. 1 to 4.

As shown in FIG. 1, the refrigerator 1 is composed of four compartments, a refrigerating compartment 1a, an ice making compartment 1b, a freezing compartment 1c and a vegetable compartment 1d. A water supply tank 4 is detachably attached to a lower corner of the refrigerating compartment 1a. In the ice making chamber 1b, an ice making machine main body 5 which receives the water for ice making from the tank 4 is arranged, and below the ice making machine main body 5, a plate-shaped ice for accumulating the produced ice. The storage container 6 is arranged so that it can be taken in and out freely. In addition, a micro switch for detecting the presence or absence of the tank is arranged at the mounting position of the water supply tank 4,
Behind this water supply tank 4 is the ice machine body 5
A pump is provided to send water to. In addition, a light emitting diode (not shown) is provided on the front of the door for the purpose of displaying an alarm prompting replenishment of water to the water supply tank 4.

FIG. 2 is a perspective view showing the appearance of the ice making machine body 5 in the vicinity of the ice tray.

A rectangular frame 21 is fixed to the gear box 20 of the ice making machine body 5, and the ice tray 2 is placed in the frame 21.
2 is rotatably supported about a horizontal axis. In the gear box 20, a motor for rotating the ice tray 22 and a micro switch for detecting that the ice tray 22 is horizontal are provided. Also,
A molded temperature sensor is attached to the back surface of the ice tray 22. The above motor, micro switch, and temperature sensor are wired to the control board 24 via the cable 23.

FIG. 3 is a circuit diagram of the control circuit of the refrigerator with the automatic ice maker according to the embodiment of the present invention described above.
The main part of this control circuit is formed on the control board 24.

The temperature sensor 12 attached to the back surface of the ice tray 22 is, for example, a thermistor having a negative resistance temperature characteristic. One end of the temperature sensor 12 and the resistor 31
Is connected at one end to a connection point 32. The other end of the temperature sensor 12 is connected to the DC power supply Vc, and the other end of the resistor 31 is connected to the ground to form a voltage dividing circuit. The analog voltage at the connection point 32 is input to the A / D converter 33 and converted into a digital signal. This digital signal is sent to a microcomputer (hereinafter referred to as a microcomputer) 34
Input to the input port of.

The tank presence / absence detection switch 35 arranged at the mounting position of the water supply tank 4 has one end grounded and the other end connected to the DC power source Vc via the resistor 36. The logic signal at the connection point 37 between the tank presence / absence detection switch 35 and the resistor 36 is input to the input port of the microcomputer 34. The attitude detection switch 38 of the ice tray 22 has one end grounded and the other end connected to a DC power supply Vc via a resistor 39. The logic signal at the connection point 40 between the attitude detection switch 38 and the resistor 39 is also input to the input port of the microcomputer 34.

One bit of the output port of the microcomputer 34 is
It is connected to the base of the NPN transistor 42 via the resistor 41. The emitter of this transistor is grounded, and the collector is connected to the DC power supply Vc via the motor 43 for rotating the ice tray 22. The other bit of the output port of the microcomputer 34 is connected to the base of the NPN transistor 45 via the resistor 44. The emitter of this transistor is grounded, and the collector is a pump motor 4 for sending water from the water supply tank 4 to the ice tray 22 of the ice machine body 5.
It is connected to the DC power source Vc via 6. The other bit of the output port of the microcomputer 34 is connected to N via the resistor 47.
It is connected to the base of the PN transistor 48. The emitter of this transistor is grounded and the collector is connected to the cathode of a light emitting diode 49 for displaying a water supply alarm. The anode of the light emitting diode 49 is a resistor 50.
Is connected to the DC power source Vc via.

In addition to the input / output port, the microcomputer 34 has a first timer, a second timer, and a memory storing a program described below.

FIG. 4 is a flow chart showing the operation of the microcomputer 34. Hereinafter, the operation of the refrigerator with the automatic ice maker according to the embodiment of the present invention will be described with reference to FIGS. 1 to 3 and this flowchart.

In step 1, an H level signal is output to the base of the transistor 45 to operate the water supply pump motor 46. Even if the pump motor 46 is operated, if the water supply tank 4 is empty, water is not actually supplied to the ice tray 22, so that a predetermined time, for example, 4.5, is applied in step 2.
After a lapse of minutes, it is checked in step 3 whether or not the sensor detection temperature T has become equal to or higher than the set temperature T3. Temperature sensor 1
Since 2 has a negative temperature characteristic, the voltage at the connection point 32 increases as the temperature increases. The analog voltage at the connection point 32 is converted into a digital signal by the A / D converter 33 and input to the microcomputer 34. The set temperature T3 is, for example, -9.5 ° C.

When the water supply tank 4 is empty, the temperature of the ice tray 22 does not rise even after 4.5 minutes. Therefore, the temperature T detected by the sensor is lower than the set temperature T3. Go to 4. In step 4, an H level signal is output to the base of the transistor 48 to turn on the light emitting diode 49, and an alarm for urging the supply of water to the water supply tank 4 is issued. This alarm continues until the water supply tank 4 is replaced. In response to the water supply alarm, the water supply tank 4 in the refrigerating compartment 2 is taken out, filled with water, and then returned to a predetermined position.
Turns off and then turns back on. Therefore, once H
The signal that returns to the L level after reaching the level is the connection point 3
7 is input to the microcomputer 34. Accordingly, the execution control of the microcomputer 34, which has detected the replacement of the water supply tank 4 in step 5, proceeds to step 6. Then, in step 6, after turning off the water supply alarm light emitting diode 49, the process returns to step 1 to operate the pump motor 46 to supply water to the ice tray 22.

When it is confirmed in step 3 that water is actually supplied to the ice tray 22 and the sensor detected temperature T becomes equal to or higher than the set temperature T3, the process proceeds from this step to step 7.

In step 7, the process waits until the temperature T detected by the sensor becomes equal to or lower than the set temperature T2 as the ice making progresses. Set temperature T
2 is, for example, -9.5 ° C. When it is confirmed that the sensor detected temperature T has become equal to or lower than the set temperature T2, in step 8, the second timer is set to, for example, 2 hours and 55 minutes, and this timer is started.

In step 9, it is checked whether or not the second timer has completed time counting. If this timing has not been completed yet, the process proceeds to step 10. Then, when this timing is completed, the process proceeds to step 11.

In step 10, the temperature T detected by the sensor is
It is determined whether or not the temperature has dropped below the set temperature T1. The set temperature T1 is, for example, -12.5 ° C. This T1 is set to the ice making completion temperature (-1 when the ice making is surely completed.
The temperature sensor 12 is at 2.5 ° C. Then, if the sensor detected temperature T has not reached the set temperature T1, the process returns to step 9, and if it has reached the process proceeds to step 11.

In step 11, the first timer is started. Then, in step 12, it is determined whether or not this timer has counted up. The time measured by this timer is set to 5 minutes. This set time is
It is the temperature from when the temperature of the ice tray 22 reaches -12.5 ° C after reaching -10.5 ° C in the normal state where the door of the refrigerator 1 is closed. Even if the door of the refrigerator 1 is opened and the sensor detection temperature T of the temperature sensor 12 rises, the time is kept for this set time regardless of the rise. This is because if the set temperature T1 (-10.5 ° C) is reached, the ice making is completed within 5 minutes even if the door of the refrigerator is slightly opened.

In step 13, the first timer and the second timer are reset, and the process proceeds to step 14.

In step 14, an H-level signal is output to the base of the transistor 42 to turn the ice tray rotating motor 43.
Operate. The operation of the motor 43 causes the ice tray 22 to rotate about a horizontal axis and turn upside down. At this point, the ice tray 22 is twisted and released, and the resulting ice is stored in the storage container 6. After the ice is removed, the attitude detection switch 38 detects that the attitude of the ice tray 22 has returned to the horizontal position, and the operation of the motor 43 is stopped at this time. When the above ice removing operation is completed, the process returns to step 1 to automatically restart the next ice making.

Since the refrigerator 1 has the first timer, the ice removing operation is performed 5 minutes after the sensor detection temperature T becomes equal to or lower than the set temperature T1. Therefore, if
There is a detection error in the temperature sensor 12, and the actual temperature has not reached the ice making completion temperature (-12.5 ° C) -10.
Even at 5 ° C., the ice removing operation is performed 5 minutes after this time, so that ice making is not completed during that time and unfinished ice is not produced.

Since the second timer is provided, the second timer completes the ice making even when the load is large or the outside air temperature is high and the sensor detection temperature does not drop below -9.5 ° C. Therefore, even if the ice making is actually completed, there is no possibility that the ice making completion cannot be detected forever.

Next, using the flow chart of FIG.
The operation of the microcomputer 34 of the second embodiment will be described. In addition,
The operations from Steps 1 to 6 and the operations from Step 11 onward are the same as those in FIG.

In step a1, the process waits until the temperature T detected by the sensor becomes equal to or lower than the set temperature T2 due to the progress of ice making. The set temperature T2 is, for example, -9.5 ° C. When it is confirmed that the sensor detection temperature T has become lower than the set temperature T2, step a
At 2, the second timer is set to 2 hours and 55 minutes, for example, and this timer is started.

At step a3, it is checked whether or not the second timer has completed time counting. If this clock has not been completed yet, the operation proceeds to step a4. Then, when this timing is completed, the process proceeds to step 11.

At step a4, if the sensor detected temperature T is equal to or lower than the set temperature T2, the process proceeds to step a6. Also,
If the sensor detected temperature T exceeds the set temperature T2, it is not an appropriate temperature for ice making. Therefore, the second timer is reset in step a5 and the process returns to step a1 to wait again until the temperature becomes equal to or lower than the set temperature T2.

At step a6, the sensor detected temperature T is
It is determined whether or not the temperature has dropped below the set temperature T1. The set temperature T1 is, for example, -12.5 ° C. This T1 is set to the ice making completion temperature (-1 when the ice making is surely completed.
The temperature sensor 12 is at 2.5 ° C. Then, if the sensor detected temperature T has not reached the set temperature T1, the process returns to step a2, and if it has reached, the process proceeds to step 11.

In this embodiment, since it is checked twice whether or not the set temperature T2 has been reached, more complete ice making control can be performed.

[0052]

In the refrigerator with the automatic ice maker according to the first aspect, the ice removing operation is performed after the first set time after the temperature detected by the temperature sensor becomes equal to or lower than the set temperature. Therefore, if
Even if the temperature sensor has a detection error and the actual temperature does not reach the ice making completion temperature, the ice removing operation is performed after the first set time from this time, so the ice making should always be performed completely. You can

In the refrigerator with the automatic ice maker according to claim 2, the second timer means is operated when the second set temperature is reached, and the operation is performed assuming that the ice making is completed after the second set time. Therefore, the refrigerator door There is no case where the completion of ice making cannot be detected even though the ice making is actually completed, such as when the ice is opened and closed or when the load is large.

In the refrigerator with the automatic ice making machine according to the third aspect, since it is checked twice whether the set temperature is reached or not, more complete ice making control can be performed.

[Brief description of drawings]

FIG. 1 is a front view of an open state of a refrigerator with an automatic ice maker according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the appearance of the vicinity of an ice tray of an automatic ice making machine.

FIG. 3 is a circuit diagram of a control circuit of the refrigerator with the automatic ice maker shown in FIG.

4 is a flowchart showing the operation of the microcomputer of FIG.

5 is a flowchart of a second embodiment showing the operation of the microcomputer shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Refrigerator 4 ... Water supply tank 5 ... Ice maker main body 12 ... Temperature sensor 22 ... Ice tray 34 ... Microcomputer 43 ... Ice tray rotation motor 46 ... Water supply pump motor

Claims (3)

[Claims] 1. A temperature sensor for detecting the temperature of an ice tray, and a first sensor for outputting a first temperature determination signal when the temperature detected by the temperature sensor is equal to or lower than a first set temperature which is an ice making completion temperature. And a first temperature determination means, and a first temperature determination signal of the first temperature determination means activates timekeeping, and when the timekeeping of the first set time is completed,
A refrigerator with an automatic ice-making machine, comprising: first timer means for outputting a time-keeping completion signal; and ice-making completion detecting means for indicating completion of ice making when the first time-keeping completion signal is input from the first timer means. 2. A second temperature determination means for outputting a second temperature determination signal when the temperature detected by the temperature sensor becomes equal to or lower than a second set temperature higher than the first set temperature, the second temperature determining means. And a second timer means for outputting a second timing completion signal when the timing is started by the second temperature determination signal of the temperature determination means and the timing of the second set time longer than the first set time is completed. The ice making completion detecting means determines that the ice making is completed when a second timing completion signal is input from the second timer means regardless of the operating states of the first temperature determining means and the first timer means. Item 1. A refrigerator with an automatic ice maker according to Item 1. 3. The ice making completion detecting means resets the second timer means when the temperature detected by the temperature sensor becomes equal to or higher than a second set temperature after the second timer means starts counting time. The refrigerator with the automatic ice maker according to claim 2, wherein the second temperature determination means waits for the second temperature determination signal to be input again.