JPH0285663A - Refrigerator with automatic ice-making device - Google Patents

Abstract

PURPOSE:To always give appropriate judgment on optimal ice making in accordance with the actual formation of ice by arranging for the completion of ice making to be known on the basis of a signal indicating the completion of a time count or when a discriminated-temperature signal is outputted. CONSTITUTION:A temperature sensor 12 detects the temperature of an ice- making tray and outputs a temperature detection signal A to both a temperature-judging means 14 and a temperature-discriminating means 16. When the load is small or the ambient air temperature is not high, the sensor-detected temperature T quickly falls below a specified temperature T2; in this case, the temperature-discriminating means 16 outputs a discriminated-temperature signal C, causing an ice-making completion signal E to be outputted, almost simultaneously with the actual completion of ice making. When the load is large or the ambient air temperature is high, the temperature-judging means 15 judges the sensor-detected temperature T to be below a specified temperature T1, and then outputs a temperature-judgment signal B, activating thereby a time count on a timing means 18; after a set time on the timing means 18, a time count-completion signal D is outputted, causing an ice making-completion signal E to be outputted.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a refrigerator with an automatic ice maker.

(Prior Art) Conventional refrigerators with automatic ice makers make ice automatically and continuously in the following manner. First, water is supplied from the water tank in the refrigerator compartment to the ice tray placed in the freezer compartment.
Cool this ice cube tray to make ice. When ice making is complete,
The ice tray is rotated upside down and then twisted to release the ice, and the resulting ice is stored in a storage container 2 placed below the ice tray. After this, water is supplied from the water supply tank to the ice tray and the next ice making process is automatically resumed.

Conventionally, a temperature sensor is attached to the back side of an ice tray, and completion of ice production is detected when the temperature detected by the temperature sensor falls below 112 degrees Celsius.

(Problem to be solved by the invention) As explained above, in the conventional refrigerator with an automatic ice maker, which detects the completion of ice making only based on the temperature detected by the sensor, when the refrigerator is filled with food, etc. If the temperature is too high or the outside temperature is high, the sensor-detected temperature will not drop below 112° C. even though ice-making has actually been completed, and the completion of ice-making may not be detected for a long time. In this case, the ice making function of the automatic ice maker remains stopped, and ice cannot be made from now on. This has been a particular problem in refrigerators with large internal volumes that have become popular in recent years.

It may be possible to detect the completion of ice making when a certain period of time has elapsed since the completion of water supply to the ice tray, but if only time control is used, the following problem arises.

In other words, when the load is large or the outside temperature is high,
As a result, the set time is too short compared to the time required for ice making, and a determination that ice making is complete is made before some of the water in the ice tray has turned into ice. Therefore, the setting time has to be lengthened in consideration of the worst external conditions. However, in this case, when the load is small or the outside temperature is not very high, the start of the next ice making is delayed even though ice making has actually been completed, and the time required to make a certain amount of ice is delayed. becomes longer.

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

[Configuration of the Invention] (Means for Solving the Problems) A refrigerator with an automatic ice maker according to the present invention has the configuration shown in FIG. 1 in order to achieve the above object. That is, a temperature sensor 12 detects the temperature of the ice tray, and when the temperature detected by the temperature sensor 12, that is, the sensor detection temperature T becomes equal to or lower than the set temperature T1, a temperature determination signal B is generated.
temperature determining means 14 that outputs a temperature determination signal C when the sensor detected temperature T becomes equal to or lower than another set temperature T2 lower than the set temperature T1; Timing means 18 that is activated and outputs a timing completion signal when timing of the set time is completed.
Completion of ice making is detected based on a timing completion signal, or completion of ice making is detected when a temperature determination signal C is output.

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

When the load is small or when the outside temperature is not very high, the sensor detected temperature T rapidly decreases to below the set temperature T2. In this case, the temperature determining means 1G outputs the temperature determining signal C almost at the same time as the actual ice making is completed. Therefore, the ice-making completion signal E is outputted without waiting for the output of the 51-hour completion signal from the clock means 18.

In addition, when the load is large or the outside temperature is high, the sensor detected temperature T is the set temperature T of the temperature determination means 16.
Even when the temperature T does not fall below 2, the temperature determining means 14 determines whether the sensor detected temperature T has decreased.

At this time, the temperature determination means 14 determines that the sensor detected temperature T has become equal to or lower than the set temperature T1, outputs a temperature determination signal B, and starts the time measurement of the time measurement means 18.

When the set time of the timer 18 has elapsed since the sensor detected temperature T became equal to or lower than the set temperature T, the timer 1B outputs a timekeeping completion signal. At this time, temperature discrimination signal C
The ice making completion signal E is outputted based on the timing completion signal without waiting for the output of the ice making completion signal E.

(Example) FIG. 2 is a front view of a refrigerator with an automatic ice maker according to an example of the present invention, with the door open.

This refrigerator 1 consists of a refrigerator compartment 2 and a freezer compartment 3 above it.
Consists of rooms. A water tank 4 is detachably attached to the upper corner of the refrigerator compartment 2. This tank is inside the freezer compartment 3.
An ice maker main body 5 is arranged to receive water supply from 4 for ice making, and a tray-shaped ice storage container 8 for collecting ice formed below the ice maker main body 5 is arranged in a manner that it can be taken out and put in freely. ing. A microswitch is provided at the mounting position of the water tank 4 to detect the presence or absence of the tank, and a pump is provided at the back of the water tank 4 to supply water from this tank to the ice maker body 5.

Furthermore, a light emitting diode is provided in front of the door for the purpose of displaying an alarm to prompt the water supply tank 4 to be filled with water.

FIG. 3 is a perspective view showing the appearance of the ice maker body 5 near the ice tray.

A rectangular frame 21 is fixed to a gear box 20 of the ice maker body 5, and an ice tray 22 is supported within this frame 21 so as to be rotatable around a horizontal axis. gear box 20
Inside, along with a motor that drives the rotation of the ice tray 22,
A microswitch is provided to detect whether the ice tray 22 is in a horizontal position. Also, ice tray 2
A molded temperature sensor is attached to the back surface of 2. The above motor, microswitch, and temperature sensor are wired to a control board 24 via a cable 23.

FIG. 4 is a circuit diagram of the control circuit of the refrigerator with automatic ice maker according to the embodiment of the present invention described above. However, the main part of this control circuit is configured on the control board 24.

The temperature sensor 12 attached to the back surface of the ice tray 22 is made of, for example, a thermistor whose resistance value has negative temperature characteristics. One end of this temperature sensor 12 and one end of the resistor 31 are
The connection is made at connection point 32 . The other end of the temperature sensor 12 is connected to a DC tS source Vc, and the other end of the resistor 31 is connected to ground, forming 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 input to the human powered boat of the microcomputer 34.

A tank presence/absence detection switch 35 disposed at the mounting position of the water tank 4 has one end grounded and the other end connected to the DC power supply VC via a resistor 36. The logic signal at the connection point 37 between the tank presence/absence detection switch 35 and the resistor 3G 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 a resistor 39. A logic signal at a connection point 40 between the attitude detection switch 38 and the resistor 39 is also manually input to the microcomputer 34 .

One bit of the output port of the microcomputer 34 is
It is connected to the base of an NPN transistor 42 via a resistor 41. The emitter of this transistor is grounded, and the collector is connected to the motor 43 that drives the rotation of the ice tray 22.
It is connected to DC type RV c via. The other bits of the output port of the microcomputer 34 are connected through a resistor 44 to the base of an NPN transistor 45. The emitter of this transistor is grounded, and the collector is connected to DC mFjVc via a pump motor 46 that supplies water from the water tank 4 to the ice tray 22 of the ice maker body 5.

Still other bits of the output port of the microcomputer 34 are connected via a resistor 47 to the base of an NPN transistor 48. 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 alarm.

The anode of this light emitting diode 49 is connected to the DC type HV c via a resistor 5o.

In addition to the above input/output board, the microcomputer 34 has an internal timer and a memory storing a program described below.

FIG. 5 is a flowchart showing the operation of the microcomputer 34. Hereinafter, the operation of the refrigerator with an automatic ice maker according to the embodiment of the present invention will be explained based on 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 supply pump motor 46.

Even if the pump motor 46 is operated, if the water supply tank 4 is empty, water will not actually be supplied to the ice cube tray 22. Therefore, in step 2, wait for a predetermined period of time, for example 4.5 minutes, to elapse. In step 3, it is checked whether the sensor detected temperature T has reached the set temperature 10 or higher. Since the temperature sensor 12 has negative temperature characteristics, the voltage at the connection point 32 increases as the temperature increases. The analog voltage at this connection point 32 is A
The signal is converted into a digital signal by the /D converter 38 and input to the microcomputer 34. In addition, the set temperature T.

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, so the sensor detected temperature T is the set temperature T. If the temperature is lower, proceed from step 3 to step 4. In step 4, an H level signal is output to the base of the transistor 48 to light up the light emitting diode 49 and issue an alarm prompting water to be refilled in the water tank 4. This alarm continues until the water tank 4 is replaced. In response to this water supply alarm, the water supply tank in the refrigerator compartment 2 is
4 and fill it with water, and then return this tank to the predetermined position, the tank presence/absence detection switch 35 switches to BO
After turning FF, it returns to ON. Therefore, a signal that returns to the L level after reaching the H level is input to the microcomputer 34 from the connection point 37. As a result, the execution control of the microcomputer 34, which detected the replacement of the water tank 4 in step 5, proceeds to step 6. and,
After turning off the water supply warning light emitting diode 49 in step 6, the process returns to step 1, and the pump motor 4B is operated to supply water to the ice making unit 111122.

Water is actually supplied to the ice tray 22 and the sensor detected temperature T
If it is confirmed in step 3 that the temperature has reached the set temperature of 10 or more, the process proceeds from this step to step 7.

In step 7, ice making progresses until the sensor detected temperature T becomes equal to or lower than the set temperature T1. For example, the set temperature T1 is -
The temperature is 10.5°C. When it is confirmed that the sensor detected temperature T has become equal to or lower than the set temperature T1, in step 8, an internal timer is set to, for example, 3 hours, and this timer is activated.

In step 9, it is checked whether the internal timer has completed counting for three hours. If this timing has not yet been completed, the process proceeds to step 10 to check whether the sensor detected temperature T has become equal to or lower than another set temperature T2 lower than the set temperature T1. The set temperature T2 is, for example, -12.0°C. If the sensor detected temperature T is higher than the set temperature T2, the process returns to step 9, but if the sensor detected temperature T falls below the set temperature T2 before the internal timer counts up, ice making completion is detected and the process returns to step 10. Proceed to step 11.

If the internal timer completes three hours of time measurement before the sensor detected temperature T becomes equal to or lower than the set temperature T2, the completion of ice making is similarly detected and the process proceeds from step 9 to step 11.

After the internal timer is reset in step 11, an H level signal is output to the base of the transistor 42 in step 12 to operate the ice tray rotating motor 43. motor 4
3, the ice tray 22 rotates around the horizontal axis and is turned upside down. At this point, the ice tray 22 is twisted to release water, and the ice produced is stored in the storage container 6.

After the ice is removed, the attitude detection switch 38 detects that the attitude of the ice making tray 22 has returned to horizontal, and at this time, the operation of the motor 43 is stopped. When the above ice removal operation is completed, the process returns to step 11 and automatically restarts the next ice making operation.

The refrigerator l with an automatic ice maker according to the embodiment of the present invention can automatically and continuously make ice as described above.

FIG. 6 is a diagram showing the change over time in the sensor-detected temperature T of the refrigerator l with an automatic ice maker according to the embodiment of the present invention when the load is small and the outside air temperature is not very high.

The sensor detected temperature T before 4.5 minutes have passed since the water supply was completed.
is the set temperature T. After reaching the above temperature, the sensor detected temperature T decreases as ice making progresses.

However, in this case, since the sensor-detected temperature T rapidly decreases, the sensor-detected temperature T decreases to the set temperature T2 at time t before three hours have elapsed since it dropped to the set temperature T1 at time t. Therefore, completion of ice making is detected at time t12.

FIG. 7 is a diagram showing a temporal change in the sensor-detected temperature T of the refrigerator l with an automatic ice maker according to the embodiment of the present invention when the outside air temperature is high. A similar temperature change occurs when the load on the refrigerator l is large.

In this case, the sensor-detected temperature T decreases slowly, and the sensor-detected temperature T does not fall below the set temperature T2 no matter how long it takes after falling to the set temperature TI at time '21. However, this refrigerator [then, time t21]
Completion of ice making is detected at time t2□, 3 hours have passed since then.

Each setting can be determined in the following manner.

In other words, the set temperature TI is determined by filling a refrigerator equipped with an automatic ice maker with food, etc., and setting the worst external conditions for the refrigerator by maintaining the outside temperature at, for example, 30°C. It may be determined by measuring the reachable limit of the sensor detection temperature T under the maximum cycle capacity. Also,
The setting time of the internal timer may be determined by setting the time required to complete ice making under this worst case condition as 3-1. On the other hand, when determining the set temperature T2, it is not necessary to consider this worst case condition.

Note that after the sensor detected temperature T becomes lower than the set temperature T1 and the internal timer starts counting the set time, if the sensor detected temperature T becomes higher than the set temperature T1 again before the timing is completed, The internal timer may be temporarily stopped or reset. In this case, the internal timer restarts counting when the sensor-detected temperature T becomes equal to or lower than the set temperature T1. Furthermore, when the internal timer completes counting the set time, the completion of ice making may be detected after confirming that the sensor detected temperature T is equal to or lower than the set temperature T1.

[Effects of the Invention] As explained above, in the refrigerator with an automatic ice maker according to the present invention, when the load is small or the outside temperature is not very high, the temperature determination means starts making ice almost at the same time as the actual ice making is completed. Since the completion is detected, it is possible to eliminate wasted time between the actual completion of ice making and the start of the next ice making. Therefore, the required amount of ice can be made in a short time.

In addition, even when the load is heavy or the outside temperature is high, and the sensor-detected temperature does not fall below the set temperature of the temperature determination means, the timer detects the completion of ice-making, so ice-making is actually completed. It is possible to solve the conventional problem of not being able to detect the completion of ice making forever despite the Moreover, since the timing means detects the completion of ice making after the temperature determining means determines that the senna-detected temperature has decreased, the completion of ice making is determined after all the water in the ice tray has turned into ice.

From the above, according to the present invention, a refrigerator with an automatic ice maker can always perform optimal ice making completion judgment in accordance with actual ice making, regardless of external conditions such as the size of the load on the refrigerator and the outside temperature. can be proposed.

[Brief explanation of the drawing]

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 with the door open, and FIG. 4 is a circuit diagram of the control circuit of the refrigerator with automatic ice maker shown in FIG. 2; FIG. 5 is a flowchart showing the operation of the microcomputer shown in the previous figure; Figure 6 is a diagram showing the change over time in sensor-detected temperature of a refrigerator with an automatic ice maker according to an embodiment of the present invention when the load is small and the outside temperature is not very high, and Figure 7 is a diagram showing the change in temperature detected by the sensor of the invention when the outside temperature is high. It is a figure showing a time change of sensor detection temperature of a refrigerator with an automatic ice maker concerning an example. Explanation of symbols 1...Refrigerator, 4...Water tank, 5...Ice maker body, 12...Temperature sensor, 14...Temperature determination means, 16...Temperature determination means, 18...・Timekeeping means, 22
...Ice tray, 34...Microcomputer, 43
...Ice tray rotating motor, 4B...Water supply pump motor, A...Temperature detection signal, B...Temperature judgment signal, C.
...Temperature discrimination signal, D...Time measurement completion signal, E...Ice making completion signal, T...Sensor detection temperature. Patent applicant Higashi Co., Ltd. 2 Agent Patent attorney Tsuta 1) Shoko (
璽゛"+, . 11,, :1 and 1 other person j ,...↓1"? J￥2 Figure 3

Claims (1)

[Claims] 1. A temperature sensor that detects the temperature of the ice tray, a temperature determination means that outputs a temperature determination signal when the temperature detected by the temperature sensor becomes equal to or lower than a set temperature, and Temperature determination means outputs a temperature determination signal when the temperature falls below another set temperature lower than the set temperature, and a time measurement is activated by the temperature determination signal and outputs a time measurement completion signal when the time measurement for the set time is completed. 1. A refrigerator with an automatic ice maker, comprising: a timer, and detects completion of ice making based on a timer completion signal or when a temperature determination signal is output.