JP2923351B2 - rice cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a rice cooker capable of determining the amount of cooked rice.

(Prior Art) Conventionally, in a rice cooker of this kind, for example, a temperature between two points is detected by a sensor for detecting the temperature of the outer surface of the pot, and it is determined whether the amount of cooked rice is large, medium or small based on the temperature rise rate. In addition, there has been known an apparatus that performs a rice cooking operation with a corresponding heating pattern based on the result of determination of the amount of cooked rice.

(Problems to be Solved by the Invention) By the way, the amount of cooked rice is roughly determined to be large, medium, and small, but in actuality, even a medium amount is slightly smaller, such as a medium amount, and a medium amount is slightly larger. May not be the center of quantity. Even in such a case, conventionally, the rice cooking operation is performed based on one predetermined heating pattern for medium amount, so that there may be a case where the rice cooking operation cannot be appropriately performed according to the actual amount of rice cooked.

Although the commercial power supply is AC100V, the voltage actually fluctuates, and the manner of the fluctuation varies from home to home. For this reason, even with the same heating pattern, the amount of heating may be too large or too small depending on the home, so that an appropriate rice cooking operation may not be performed.

Therefore, an object of the present invention is to provide a rice cooker that can always perform an appropriate rice cooking operation according to the amount of cooked rice.

[Structure of the Invention] (Means and Actions for Solving the Problems) The invention according to claim 1 is a rice cooker that measures an elapsed time during rice cooking and adjusts a heating amount at the next rice cooking according to the measured time. It is in.

The invention according to claim 2 is a rice cooker that measures elapsed time during rice cooking, and cooks rice with a heating amount adjusted according to the result of the measured time when the elapsed time until next rice cooking is within a predetermined time. is there.

The invention according to claim 3 is the rice cooker according to claim 1 or 2, wherein the amount of rice cooked during the next rice cooker is determined by the elapsed time during the rice cooking such as a boiling period or the total length of the rice cooked. It is to determine the heating amount.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a vessel main body. The vessel main body 1 includes an outer case 3 and an inner case 4 joined by an upper frame 2, and a rice cooker 5 is provided on the inner bottom of the inner case 4. The heater 6 is provided on the side.

Reference numeral 7 denotes a rice cooker which is removably accommodated in the inner case 4, and a cup-shaped heat-sensitive portion 8 is provided on the inner case 4 so as to elastically press against the outer bottom of the pot 7.
The pan 7 contains rice 9 and water 10.

A pot temperature sensor 11, which is a first sensor for detecting the pot temperature, is enclosed in the heat-sensitive portion 8 by a mold member 12 having heat conductivity.

Reference numeral 13 denotes an outer lid pivotally provided so as to open and close the upper opening of the vessel body 1. The outer lid 13 has a hollow structure and has a steam vent.
The cover 13 is provided with a heat retaining heater 6 disposed in a hollow portion thereof.

Reference numeral 15 denotes a cylindrical stud provided at the center of the lower surface of the outer lid 13, and an inner lid 17 is suspended from the stud 15 via a bush 16, and the inner lid 17 has a packing 18 on an outer peripheral edge. And
The upper opening of the pan 7 can be closed elastically.

The inner lid 17 is elastically pressed against the upper opening of the pan 7 via a bush 16 made of an elastic member such as silicon rubber so as to keep the hermetically closed state by the packing 18, and the steam pressure in the pan 7 is reduced. When the pressure is too high, the inner lid 17 is pushed up against the pressing force of the bush 16 by the vapor pressure, and the steam is discharged from the gap between the inner lid 17 and the pan 7. In this case, a stainless spring or the like may be used instead of the bush 16.

Reference numeral 19 denotes a cup-shaped heat sensing portion provided at the lower end of the stud 15 so as to face the inside of the pot 7. Inside the heat sensing portion 19, a lid sensor 20 serving as a second sensor for detecting the air temperature in the pot 7 is provided. Are sealed by a mold member 21 having heat conductivity.

Reference numeral 22 denotes an electronic circuit unit provided at the bottom of the vessel main body 1, which controls the input of the rice cooking heater 5 and the warming heater 6 based on temperature detection information and the like of the pot temperature sensor 11 and the lid sensor 20. ing.

FIG. 2 shows a circuit housed in the electronic circuit unit 22. A constant voltage circuit 33 is connected to a commercial AC power supply 31 via a power transformer 32, and a microcomputer 34 is connected to an output terminal of the constant voltage circuit 33. Is connected.

The rice cooker 5 is connected to the power supply 31 via a normally open contact 35a of a relay 35. And the relay
The warming heater 6 is connected in parallel to the 35 normally open contacts 35a via a bidirectional three-terminal thyristor 36.

The input terminals of the microcomputer 34 are connected to the pot temperature sensor 11 and the lid sensor 20, and the output terminals of the microcomputer 34 control the drive of the relay drive circuit 37 and the thyristor 36 for controlling the energization of the coil 35c of the relay 35. Thyristor drive circuit 38 is connected. The relay drive circuit 37 and the thyristor drive circuit 38 constitute a heater drive circuit.

As shown in FIG. 3, the microcomputer 34 includes a microprocessor 41 constituting a control unit main body, a memory for temporarily storing data processed by the microprocessor 41, a memory for storing various setting data, and the like. 42, a timing circuit 43 for measuring time, each of the sensors 11, 2
Input circuit with A / D conversion function 44 for input control of signal from 0
And an output circuit for outputting a control signal to the heater drive circuit
Consists of 45. Wherein the memory 42 for example a small amount, a medium amount, a large amount of time for boiling detection in response to rice amount t ₂ memory and this time storing level which corresponds to t ₂
There is provided a table in which the relationship between the level and the time for setting is set. In this table, a small amount, a medium amount, and a large amount are each divided into seven levels of -3 to +3. For example, when the amount is small, level-3 is 16 seconds, level-2 is 32 seconds, level-1 is 48 seconds, and level-1 is 48 seconds. Level 0 corresponds to 4 seconds, Level 1 corresponds to 80 seconds, Level 2 corresponds to 96 seconds, Level 3 corresponds to 112 seconds, and at medium amount, Level-3 is 96 seconds, Level-2 is 112 seconds, Level-1 Is 128 seconds, level 0 is 144 seconds, level 1 is 160
Seconds, Level 2 corresponds to 176 seconds, Level 3 corresponds to 192 seconds, and in large quantities, Level-3 is 160 seconds and Level-2 is 176 seconds.
Seconds, level -1 for 192 seconds, level 0 for 208 seconds, level 1 for
224 seconds, level 2 is set to 240 seconds, and level 3 is set to 256 seconds.

A program is set in the microprocessor 41 so as to perform control based on the flowcharts shown in FIGS.

FIG. 4 shows the rice cooking control. First, the rice cooking control is performed, and when the rice cooking is completed, the actual rice cooking, that is, the rice cooking operation is performed. The rice cooking operation is performed, and when the washing operation is completed, a series of rice cooking control is ended.

The hot-boiled cooking control is performed based on FIG. That is, the relay drive circuit 37 is controlled to drive the relay 35 to turn on the rice cooker 5. At the same time, the timer circuit 43 starts time measurement.

When two minutes have elapsed, the rice cooker 5 is turned off.
After another 6 minutes have passed in this state, the rice cooker 5 is turned on again.
The rice cooker 5 is turned on, and after one minute has elapsed, the rice cooker 5 is turned off. When a further 6 minutes have elapsed in this state, the endless cooking control is terminated.

That is, the hot-boiled rice cooking control is performed for 15 minutes, and the water temperature is raised to some extent to make the water absorption of the rice 9 25% or more.

The rice cooking control is performed based on FIG. That is, the relay drive circuit 37 is controlled to drive the relay 35 to turn on the rice cooker 5.

Then, a capacity determination process is performed. (Capacity Judgment Means) When this capacity judgment process is completed, the process waits until the detected temperature T of the lid sensor 20 becomes T ≧ 90 ° C., and when T ≧ 90 ° C., the boiling detection process is performed. (Boiling detection means) When this boiling detection is completed, input control, that is, heating amount control during boiling is performed. (Boiling control means) Then, the pot temperature sensor 11 detects a predetermined cooking temperature, for example, 12
When 0 ° C or more is detected, it is determined that cooking is finished and the rice cooking is completed.

The capacity determination process in this rice cooking control is performed based on FIG. First to start measuring the time t ₁ to the time counting circuit 43. Then, it waits for the lid sensor 20 to detect a temperature rise of 15 deg. When the lid sensor 20 detects a temperature rise of 15 deg, reading measured time t ₁ of the timer circuit 43 at that time.

If t ₁ <4 minutes 20 seconds, it is determined that the amount of cooked rice is small. If 4 minutes 20 seconds ≦ t ₁ <6 minutes 20 seconds, it is determined that the rice cooking amount is medium. Also it determined that rice amount if 6 minutes 20 seconds ≦ t ₁ is mass.

The boiling detection process in the rice cooking control is performed based on FIG. This calls time t ₂ for the boiling detection by referring to the table from the level and capacity the determined cooking amount stored in the memory 42, the rate of increase in the temperature detected by the pot temperature sensor 11 is 5deg less / Check whether it is a t _2, it determines the boiling detection end and detects that it is now 5deg less / t _2. The temperature detected by the pot temperature sensor 11 at this time is set in the memory 42 as the reference temperature ST.

The input control in the rice cooking control is performed based on FIG. First, it is checked whether the amount of cooked rice is a small amount course. If the course is a small amount course, the heating operation is performed by lowering the electricity supply rate to the rice cooker 5 to 1/3 of the current rate. This is performed by turning off the normally open contact 35a of the relay 35 and controlling the conduction phase angle of the thyristor 36 by the thyristor drive circuit 38 instead.

Subsequently, it is checked whether or not the detected temperature T of the pan temperature sensor 11 has become T ≧ ST + 2 deg. If T ≧ ST + 2 deg, the power supply rate to the rice cooker 5 is further reduced to 1/4 to perform the heating operation. . When T ≧ ST + 2 deg does not hold, after 5 minutes have elapsed, the power supply rate to the rice cooker 5 is further reduced to 1/4 to perform the heating operation.

If the course is not a small course, that is, a middle course or a large course, the energization rate to the rice cooker 5 is changed to 4/7.
And the heating operation is performed.

Subsequently, it is checked whether or not the detected temperature T of the pan temperature sensor 11 has become T ≧ ST + 2 deg. If T ≧ ST + 2 deg, the power supply rate to the rice cooker 5 is further reduced to 3 to perform the heating operation. . When T ≧ ST + 2 deg does not hold, after 5 minutes have passed, the power supply rate to the rice cooker 5 is further reduced to 3 to perform the heating operation.

Further, the cooking detection process in the rice cooking control is performed based on FIG. First, it is checked whether or not the detected temperature T of the pan temperature sensor 11 has become T ≧ ST + 5 deg.
At ST + 5 deg, the rice cooker 5 is turned off. Then, it is checked whether or not T ≧ ST + 7 deg, and T ≧ ST +
When the temperature reaches 7 deg, the cooking detection is terminated and the process proceeds to the next spotting operation. When T ≧ ST + 7 deg does not hold, after one minute has passed, the power supply rate to the rice cooker 5 is reduced to 3 and the heating operation is performed again.

When the detected temperature T of the pan temperature sensor 11 becomes T ≧ 120 ° C., the detection of cooking is finished, the rice cooker 5 is turned off, and the process proceeds to the next spotting operation.

This unevenness operation is performed, for example, for about 13 minutes, and the rice cooker 5 is operated several times in a short time at 100% duty ratio, and is cooked twice in the middle. It should be noted that when the spotting operation is completed, the heat retaining operation by the heat retaining heater 6 is started.

FIG. 11 shows a setting process constituting the time correcting means. In this process, when the temperature rise rate becomes 5 deg or less / t ₂ and the boiling detection is completed, the time counting circuit 43 starts measuring the time t ₃ . . And thereafter cooked up detection is stored in the memory 42 reads the measured time t ₃ according to the performed counting circuit 43.

And this measurement time t ₃ is t ₃ <2 minutes or 2 minutes ≦ t ₃ <6
Minutes, 6 minutes ≦ t ₃ <8 minutes, 8 minutes ≦ t ₃ <12 minutes, t ₃ ≧ 12 minutes. If t ₃ <2 minutes, the adjustment value is -2 level. If 2 minutes ≦ t ₃ <6 minutes, the adjustment value is −1 level. If 6 minutes ≦ t ₃ <8 minutes, the adjustment value is 0. Level and 8
If min ≦ t ₃ <12 min, the adjustment value is set to the +1 level, and t ₃ ≧ 12
If it is a minute, the adjustment value is set to +2 level.

Then thus obtained adjustment value is added to the level of the boiling detection time t ₂ used this time, to set the level of the boiling detection time t ₂ to be used for cooking the next.

This setting value is effective when rice is cooked with the same amount of cooked rice within 72 hours, but if rice is not cooked even after 72 hours, the boiling detection time t2 to be used at the next rice cooking time t ₂ Is changed to the 0 level. When the next rice cooking is different from the current rice cooking amount, the level is changed to the 0 level.

In the present embodiment having such a configuration, when a predetermined amount of rice 9 and water 10 are stored in the rice cooker 7 and the rice cooking is started, first, the overcooking operation is performed for 15 minutes. The rice 9 absorbs moisture of 25% or more by this hot cooking operation.

When the rice cooking is completed, the main rice cooking, that is, the rice cooking operation is started. The detected temperature of the pan temperature sensor 11 first from the time of cooking start in this cooking time t ₁ to rise 15deg is measured. The cooking amount by the measured time t ₁ is a small amount or, or medium heavy, a large amount of them is determined.

Thereafter, when the detected temperature T of the lid sensor 20 becomes 90 ° C. or more, the boiling detection is started. In this boiling detection, memory 42
Time t ₂ for the boiling detection by referring to the table is called from the level and the determined cooking amount stored in. For example, if the level is “0” and the amount of cooked rice is medium, the time t ₂ = 144 seconds for boiling detection is called.

When the temperature rise rate becomes 5 deg or less / t ₂ , the boiling detection ends, and the temperature T detected by the pot temperature sensor 11 at that time is set in the memory 42 as the reference temperature ST. The measurement of the time t ₃ is started by the timer circuit 43.

After the completion of the boiling detection, the heating control of the rice cooker 5 according to the amount of cooked rice is started, and the boiling operation is continued. That is, when the amount is small, the energization rate to the rice cooking heater 5 becomes 1/3, and the detection temperature T of the pot temperature sensor 11 is T ≧ ST + 2 deg.
Or after 5 minutes, the power supply rate to the rice cooker 5
It becomes 1/4. When the amount is medium or large, the rice cooker 5
To the rice cooker 5 becomes 4/7, and the temperature T detected by the pot temperature sensor 11 becomes T ≧ ST + 2 deg.

When the detected temperature T of the pan temperature sensor 11 becomes T ≧ ST + 5 deg, the rice cooker 5 is turned off, and within one minute, T ≧ ST + 7.
When the temperature reaches deg, the cooking is detected and the boiling operation ends.
If T ≧ ST + 7 deg does not come within one minute, the rice cooker 5 is turned on again at a duty ratio of 1/3. When T ≧ 120 ° C., the cooking is detected and the boiling operation is terminated.

When the detection of cooking is performed, the measurement of the time t ₃ by the timer circuit 43 is terminated, and the measured time t ₃ is stored in the memory 42. Further, when the cooking detection is performed, a spotting operation is performed thereafter, and the spotting operation is performed for about 13 minutes. In this spotting operation, cooking is performed twice by the rice cooker 5, and when the spotting operation is completed, the operation shifts to a warming operation.

FIG. 12 shows the above operation in a graph. In FIG. 12, the solid line graph a represents a pot temperature sensor.
11 indicates the detected temperature, the dotted line graph b indicates the detected temperature of the lid sensor 20, and the hatched portion of the rice cooker indicates energization.

Further, when the measured time t ₃ in the memory 42 by detecting elevated cooking are stored, the time t ₃ is the adjustment value level is determined by how much time. For example the adjustment value +1 level is determined if the time t ₃ is 8 minutes 30 seconds. And now, the level in the rice amount of medium amount is +1 level is level for determining the time t ₂ 0 + 1 for the next boiling detection if it is "0". That is, this means that the temperature at the time of the detection of boiling this time is slightly too low, so that the level is increased by +1 to increase the temperature at the time of detection of boiling at the next rice cooking.

Thus the same cooking amount next cooking is the time, and 160 seconds for the time t ₂ for the boiling detection was now 144 seconds when performed within medium- a and 72 hours i.e.. That is, when the temperature rise rate becomes 5 deg or less / 160 seconds, the boiling detection is performed.

If the amount of cooked rice is small or medium, or if the next cooked rice is not started within 72 hours,
The level stored in 42 is changed from the +1 level to the 0 level.

Thus heat amount for cooking amount by a time t ₃ until boiling is detected up cooking since the detection is judged whether it is appropriate, so that the appropriate amount of heat at the time of the next cooking when not appropriate Since the rate of temperature rise for boiling detection is corrected, for example, if the amount of cooked rice is always slightly larger than the center of the medium amount in a certain household, the rice cooking operation can be performed with an appropriate heating amount corresponding to the amount. . In addition, the rice cooking operation can be performed with an appropriate heating amount corresponding to the power supply voltage situation in a certain home.

Therefore, it is possible to always perform an appropriate rice cooking operation according to the amount of cooked rice.

In the above embodiment, the temperature rise rate for the boiling detection is corrected based on the time from when the boiling is detected to when the cooking is detected, but the correction is not necessarily limited to this. The total time from the start of the cooking operation to the end of the roasting operation may be measured, and the rate of temperature rise for boiling detection may be corrected based on the measured time.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide a rice cooker that can always perform an appropriate rice cooking operation according to the amount of cooked rice.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a sectional view,
FIG. 2 is a block diagram showing a main circuit configuration, FIG. 3 is a block diagram showing a configuration of a microcomputer, FIGS. 4 to 11 show control by a microprocessor, and FIG. , FIG. 5 is a flow chart of the hot-cooking control, FIG. 6 is a flow chart of the main rice cooking control, FIG. 7 is a flow chart of a capacity determination process in the main rice cooking control, FIG. 9 is a flow chart of the input control process in the main rice cooking control, FIG. 10 is a flowchart of a cooking detection process in the main rice cooking control, FIG. 11 is a flowchart of a level setting process, and FIG. 12 is a detection temperature change and the rice cooking in the rice cooking operation. It is a graph which shows the electricity supply state of a heater. 5: rice cooker, 7: rice cooker, 11: pot temperature sensor (first sensor), 20: lid sensor (second sensor), 34: microcomputer, 41: microprocessor, 42: memory, 43: timekeeping circuit.

Claims (3)

(57) [Claims] 1. A rice cooker characterized by measuring an elapsed time during rice cooking and adjusting a heating amount at the time of next rice cooking according to the measured time. 2. A method of measuring the elapsed time during rice cooking, and cooking rice with a heating amount adjusted according to the result of the measured time when the elapsed time until the next rice cooking is within a predetermined time. vessel. 3. The heating amount according to the amount of rice cooked in the next rice cooking is determined based on the elapsed time during the cooking of rice, such as a boiling period, or the total length of rice cooking. Or the rice cooker according to 2.