JPH0765833B2 - Refrigerator with automatic ice machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a refrigerator with an automatic ice maker.

(Prior Art) In a conventional refrigerator with an automatic ice maker, ice is automatically and continuously produced as follows. First, supply water from the water tank in the refrigerating compartment to the ice tray in the freezing compartment,
Cool the ice tray to make ice. When ice making is completed,
After rotating the ice tray to turn it upside down, twist it to remove ice, and collect the resulting ice 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.

By the way, conventionally, a temperature sensor is attached to the back surface of the ice tray, and the completion of ice making is detected when the temperature detected by the temperature sensor becomes -12 ° C or lower.

(Problems to be Solved by the Invention) As described above, in the conventional refrigerator with an automatic ice maker that detects the completion of ice making only by the sensor detection temperature, when the food etc. is packed in the refrigerator, that is, the load is large. In some cases, or when the outside air temperature is high, the temperature detected by the sensor does not fall below -12 ° C even though the ice making is actually completed, and the completion of ice making may not be detected forever. In this case, the ice making function of the automatic ice making machine remains stopped, and thereafter ice making cannot be performed. This has been a particular problem in refrigerators with large internal volumes, which have become widespread in recent years.

It may be possible to detect the completion of ice making after a certain time has elapsed from the completion of water supply to the ice tray, but there is the following problem when only time control is performed. In other words, if the load is heavy or the outside air temperature is high, the set time will be too short compared to the time required for ice making, and the ice making will be completed before a part of the water in the ice making tray has become ice. Will be judged. Therefore, the setting time must be lengthened in consideration of the worst external condition. However, in this case, when the load is small or the outside air temperature is not too high, the start of the next ice making is delayed even though the ice making is actually completed, and the time required to make a certain amount of ice Becomes longer.

In view of the above points, the present invention provides a refrigerator with an automatic ice maker that can always perform an optimum ice making completion determination in accordance with actual ice making irrespective of external conditions such as the load size of the refrigerator and the outside temperature. The purpose is to provide.

[Structure of the Invention] (Means for Solving the Problems) The refrigerator with the automatic ice maker according to the present invention has the structure shown in FIG. 1 in order to achieve the above object. That is, the temperature sensor 12 that detects the temperature of the ice tray and the temperature detected by the temperature sensor 12, that is, the sensor detection temperature T
When the temperature becomes equal to or lower than the set temperature T _1, the temperature judgment means 14 which outputs the temperature judgment signal B and the sensor detection temperature T are set to the set temperature T ₁
When the temperature judgment means 16 outputs the temperature judgment signal C when the temperature becomes lower than another lower set temperature T ₂ and the time judgment signal B starts the time measurement, when the time measurement of the set time is completed, the time measurement completion signal D And a time measuring means 18 for outputting the completion of ice making is detected based on the time completion signal D, or the completion of ice making is detected when the temperature discrimination signal C is output.

(Operation) The temperature sensor 12 detects the temperature of the ice tray and outputs the temperature detection signal A corresponding to this temperature to the temperature determination means 14 and the temperature determination means 16.

When the load is small or the outside air temperature is not too high, the sensor detection temperature T rapidly drops to the set temperature T ₂ or less. In this case, the temperature discriminating means 16 outputs the temperature discriminating signal C almost at the same time as the actual completion of ice making. Therefore, the ice making completion signal E is output without needing to output the time measurement completion signal D from the time measuring means 18.

Further, even when the load is large or the outside air temperature is high, and the sensor detection temperature T does not fall below the set temperature P ₂ of the temperature determination means 16, the temperature determination means 14 determines that the sensor detection temperature T has decreased. To do. At this time, the temperature determination means 14
It is determined that the sensor detected temperature T has become equal to or lower than the set temperature T ₁ , the temperature determination signal B is output, and the timekeeping of the timekeeping means 18 is started. When the set time of the time measuring means 18 elapses after the sensor detection temperature T becomes equal to or lower than the set temperature T ₁ , the time measuring means 18 outputs the time measurement completion signal D. At this time, the temperature discrimination signal C
The ice-making completion signal E is output based on the time measurement completion signal D without waiting for the output of.

(Embodiment) FIG. 2 is a front view of a refrigerator with an automatic ice maker according to an embodiment of the present invention in an open door state.

This refrigerator 1 has a refrigerating room 2 and a freezing room 3 above it.
It consists of a room. A water supply tank 4 is detachably attached to the upper corner of the refrigerating compartment 2. In the freezer compartment 3, an ice maker main body 5 which receives the water for ice making from the tank 4 is arranged, and a plate-like ice storage for storing ice is formed below the ice maker main body 5. The container 6 is arranged so that it can be taken in and out freely. A micro switch for detecting the presence / absence of a tank is arranged at the mounting position of the water supply tank 4, and a pump for supplying water from the tank to the ice maker main body 5 is provided in the back of the water supply tank 4. Further, a light emitting diode 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. 3 is a perspective view showing the external appearance of the ice making machine main body 5 in the vicinity of the ice tray.

A rectangular frame 21 is fixed to the gear box 20 of the ice maker main body 5, and an ice tray 22 is supported in the frame 21 so as to be rotatable about a horizontal axis. Inside the gearbox 20, together with the motor that drives the rotation of the ice tray 22,
Is provided with a micro switch for detecting that the posture is horizontal. 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. 4 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. However, the main part of this control circuit is formed on the control board 234.

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 one end of the resistor 31 are connected at a connection point 32.
Connected in. The other end of the temperature sensor 12 has a DC power source Vc
And the other end of the resistor 31 is connected to the ground to form a voltage dividing circuit. The analog voltage at connection point 32 is A / D
It is input to the converter 33 and converted into a digital signal.
This digital signal is input to the input port of the microcomputer 34.

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 supply Vc via the resistor 36. The ethical 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 the DC power supply Vc via the resistor 39. The ethical signal at the connection point 40 between the posture 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 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 a DC power supply Vc via a motor 43 that drives the rotation of the ice tray 22. The other bit of the output port of the microcomputer 34 is connected to the NPN transistor 4 via the resistor 44.
Connected to the base of 5. The emitter of this transistor is grounded, and the collector is connected to a DC power supply Vc via a pump motor 46 that feeds water from the water supply tank 4 to the ice tray 22 of the ice machine body 5. Further bits of the output port of the microcomputer 34 are connected to the base of the NPN transistor 48 via the resistor 47. The emitter of this transistor is grounded and the collector is connected to the cathode of a light emitting diode 49 for indicating a water supply alarm. The anode of the light emitting diode 49 is connected to a DC power source via a resistor 50.
Connected to Vc.

The microcomputer 34 has an internal timer and a memory storing a program described below, in addition to the input / output port.

FIG. 5 is a flow chart showing the operation of the microcomputer 34. The operation of the refrigerator with the automatic ice maker according to the embodiment of the present invention will be described below with reference to FIGS. 2 to 4 and this flowchart.

In step 1, an H level signal is output to the base of the transistor 45 to operate the water feed 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. Therefore, in Step 2, wait for a predetermined time, for example, 4.5 minutes, and then perform sensor detection. It is checked in step 3 whether or not the temperature T has become equal to or higher than the set temperature T ₀ . Since the temperature sensor 12 has a negative temperature characteristic, the voltage at the connection point 32 becomes higher as the temperature becomes higher. The analog voltage at the connection point 32 is converted into a digital signal by the A / D converter 33 and input to the micro converter 34. The set temperature T ₀ is −9.5 ° C., for example.

When the water supply tank 4 is empty, the temperature of the ice tray 22 does not rise even after 4.5 minutes have passed, so the sensor detection temperature T is lower than the set temperature T ₀ , and the process proceeds from step 3 to step 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.
The tank presence / absence detection switch 35 turns off and then turns back on. Therefore, a signal which once becomes H level and then returns to L level is input from the connection point 37 to the microcomputer 34. As a result, the execution control of the micro converter 34, which has detected the replacement of the water supply tank 4 in step 5, proceeds to step 6. Then, in step 6, the water supply alarm light emitting diode 49 is turned off, and then 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 the water temperature is actually supplied to the ice tray 22 and the sensor detected temperature T becomes equal to or higher than the set temperature T0, 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 T ₁ as the ice making progresses. The set temperature T ₁ is, for example, -10.5
℃. When it is confirmed that the sensor detected temperature T has become equal to or lower than the set temperature T ₁ , the internal timer is set to, for example, 3 in step 8.
Set the time and start this timer. Step 9
Then, it is checked whether or not the internal timer has completed the counting of 3 hours. If this timing has not been completed yet, the routine proceeds to step 10, where it is checked whether the sensor detected temperature T has become equal to or lower than another set temperature T ₂ lower than the set temperature T ₁ . Set temperature T
₂ is, for example, -12.0 ° C. If the sensor detection temperature T is higher than the set temperature T ₂ , the process returns to step 9. However, if the sensor detection temperature T becomes equal to or lower than the set temperature T ₂ before the internal timer counts up, completion of ice making is detected. Step
Go from 10 to step 11. Sensor detection temperature T is set temperature
Even when the internal timer completes measuring the time of 3 hours before the time becomes equal to or less than T ₂ , the completion of ice making is detected and the process proceeds from step 9 to step 11.

After resetting the internal timer in step 11, step 12
Then, an H level signal is output to the base of the transistor 42 to operate the ice tray rotating motor 43. The operation of the motor 43 causes the ice tray 22 to rotate about a horizontal axis and turn upside down. At this point, a twist is added to the ice tray 22 to release the ice,
The resulting ice is stored in the storage container 6. After removing ice, ice tray
The attitude detection switch 38 detects that the attitude of 22 has returned to horizontal, 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.

In the refrigerator 1 with the automatic ice maker according to the embodiment of the present invention, ice can be automatically and continuously produced as described above.

FIG. 6 is a diagram showing a time change of the sensor detection temperature T of the refrigerator 1 with the automatic ice maker according to the embodiment of the present invention when the load is small and the outside air temperature is not so high.

After the sensor detection temperature T becomes equal to or higher than the set temperature T ₀ before 4.5 minutes have elapsed from the completion of the water supply, the sensor detection temperature T decreases as the ice making progresses. However, in this case, since the sensor detected temperature T rapidly decreases, the sensor detected temperature T reaches the set temperature T ₂ at the time t ₁₂ before 3 hours have elapsed after the temperature fell to the set temperature T ₁ at the time t _11. Go down. Therefore, completion of ice making is detected at time t ₁₂ .

FIG. 7 is a diagram showing a time change of the sensor detection temperature T of the refrigerator 1 with the automatic ice maker according to the embodiment of the present invention when the outside air temperature is high. The same temperature change is exhibited when the load of the refrigerator 1 is large.

In this case, the sensor detection temperature T slows down slowly, and the sensor detection temperature T does not drop below the set temperature T ₂ no matter how long it has dropped to the set temperature T ₁ at time t ₂₁ . However, in this refrigerator 1, from time t ₂₁ to 3
To detect the ice making completion in time t ₂₂ of time has elapsed.

Each setting can be determined by the following method. That is, the set temperature T1, the food is packed in the refrigerator to be equipped with an automatic ice maker, the outside temperature is kept at, for example, 30 ℃ to set the worst external condition of the refrigerator,
The reachable limit of the sensor detection temperature T under the maximum capacity of the refrigeration cycle may be measured and determined. The set time of the internal timer may be determined by measuring the time required for completion of ice making under the worst conditions. On the other hand, it is not necessary to consider this worst condition when determining the set temperature T ₂ .

If the sensor detection temperature T becomes lower than the set temperature T ₁ and the internal timer starts measuring the set time, and the sensor detection temperature T becomes higher than the set temperature T ₁ before the completion of the time measurement, The clock of the internal timer may be temporarily stopped or reset. In this case, next, when the sensor detected temperature T becomes equal to or lower than the set temperature T ₁ , the time measurement of the internal timer is restarted. Further, the completion of ice making may be detected after confirming that the sensor detection temperature T is equal to or lower than the set temperature T ₁ at the time when the internal timer finishes measuring the set time.

[Effects of the Invention] As described above, in the refrigerator with the automatic ice maker according to the present invention, when the load is small or the outside air temperature is not too high, the temperature determining means makes the ice making substantially at the same time as the actual completion of ice making. Since the completion is detected, waste of time from the actual completion of ice making to the start of the next ice making can be eliminated. Therefore, the required amount of ice can be produced in a short time.

Even when the load is large or the outside air temperature is high and the sensor detection temperature does not fall below the set temperature of the temperature determination means, the time measurement means detects the completion of ice making, so the ice making is actually completed. Even if it does, it is possible to solve the conventional problem that the ice making completion cannot be detected forever. Moreover, since the completion of the ice making is detected by the time measuring means after the decrease in the temperature detected by the sensor is judged by the temperature judging means, the completion of the ice making is judged after all the water in the ice making tray becomes ice.

From the above, according to the present invention, regardless of external conditions such as the size of the load of the refrigerator and the outside air temperature, the refrigerator with an automatic ice maker that can always perform the optimum ice making completion determination according to the actual ice making Can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a refrigerator with an automatic ice maker according to the present invention, FIG. 2 is a front view of the refrigerator with an automatic ice maker according to an embodiment of the present invention in an open state, and FIG. FIG. 4 is a perspective view showing the appearance of the vicinity of the ice tray of the automatic ice making machine, FIG. 4 is a circuit diagram of the control circuit of the refrigerator with the automatic ice making machine of FIG. 2, and FIG. 5 is a flow chart showing the operation of the microcomputer of the previous figure. FIG. 6 is a diagram showing the time change of the sensor detection temperature of the refrigerator with the automatic ice maker according to the embodiment of the present invention when the load is small and the outside air temperature is not so high, and FIG. 7 is the present invention when the outside air temperature is high. FIG. 6 is a diagram showing a time change of the sensor detection temperature of the refrigerator with the automatic ice maker according to the example of FIG. Explanation of reference numerals 1 ... Refrigerator, 4 ... Water supply tank, 5 ... Ice machine main body, 12 ... Temperature sensor, 14 ... Temperature determination means, 16 ... Temperature determination means, 18 ...
Clocking means, 22 ... Ice tray, 34 ... Microcomputer, 43
... ice tray rotation motor, 46 ... water supply pump motor, A ... temperature detection signal, B ... temperature determination signal, C ... temperature determination signal, D ...
Timing completion signal, E ... ice making completion signal, T ... sensor detection temperature.

Claims (1)

[Claims] 1. A temperature sensor for detecting the temperature of an ice tray, temperature determination means for outputting a temperature determination signal when the temperature detected by the temperature sensor is lower than a set temperature, and the temperature sensor for detecting the temperature. Temperature determination means for outputting a temperature determination signal when the temperature becomes lower than the other set temperature lower than the set temperature, and timing is started by the temperature determination signal,
An automatic ice making device, comprising: a time measuring means for outputting a time measuring completion signal when the time measuring of the set time is completed, and detecting the completion of the ice making based on the time measuring completion signal or when the temperature discrimination signal is output. Machine-equipped refrigerator.