JPH04197319A - Rice-cooker - Google Patents

Abstract

PURPOSE:To arrange so that an appropriate rice cooking action that is accord ing to a rice cooking quantity, may be able to be conducted at all times, by providing a time correcting means at which a time during which a boiling action is conducted, is measured, and on the basis of this measured time, a boiling inspection time which is set at a memory and is opposite to the same rice cooking quantity, is corrected. CONSTITUTION:A microcomputer 34 is constituted with a micro processor 41 constituting a control portion main body, a memory 42 where a memory at which data processed by the processor 41 are temporarily housed, and a memory or the like at which various setting data are housed, are provided, and a metering circuit 43 and the like conducting time measuring. At the memory 42, for example, a memory which houses levels that are opposite to boiling inspection times t2 that are opposite to a small rice cooking quantity, a medium rice cooking quantity and a large rice cooking quantity, and a table which sets the relation of time and levels whose purpose is to set these times t2, are provided. And on the basis of its measured time, it follows that a boiling inspection time which is set at the memory and is opposite to the same rice cooking quantity, is corrected, and boiling inspection is conducted.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a rice cooker that can determine the amount of cooked rice.

(Prior art) Conventionally, in this type of rice cooker, for example, a sensor that detects the outer surface temperature of the pot detects the temperature between two points, and based on the temperature rise rate, it can be determined whether the amount of rice being cooked is large, medium, or small. It is known that rice cooking operations are performed using corresponding heating patterns based on the rice cooking amount determination results.

(Invention or problem to be solved) By the way, do we roughly judge the amount of rice cooked as large amount, medium amount, and small amount?In fact, even if it is medium amount, it is medium amount such as slightly less medium amount and slightly more medium amount. It may not be the center of the world. Even in such a case, in the past, the rice cooking operation was performed based on one predetermined heating pattern for medium-sized rice, so there were cases where the rice cooking operation could not be performed appropriately depending on the actual amount of rice cooked.

Furthermore, although the commercial power source is AClooV, there are actually voltage fluctuations, and the way the voltage fluctuates differs from household to household. For this reason, even if the heating pattern is the same, the amount of heating may be too much or too little depending on the household, and the rice may not be cooked properly in some cases.

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

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a rice cooking heater that heats a pot and performs a rice cooking operation;
A first sensor that detects the temperature of the pot, a second sensor that detects the temperature of the space above the pot, a clock circuit that measures time, and a first sensor that detects the temperature of the pot after the rice cooking operation starts. capacity determination means for measuring the time until detecting a predetermined temperature A and determining the amount of rice cooked based on the measured time; a memory in which a time for boiling detection is set according to each amount of rice cooked; and a capacity determination means. The rate of temperature rise is calculated from the time for boiling detection recalled from the memory based on the amount of cooked rice determined by the method and the change in temperature detected by the second sensor, and the rate of temperature rise is determined according to the amount of cooked rice. Boiling detection means detects boiling when the temperature rise rate is below or below, and when the boiling detection means fails to detect boiling, the capacity determining means controls the reduction of the heating amount by the rice cooking heater based on the amount of rice determined by the capacity determination means. , and then a boiling control means that stops the boiling operation when the sensor in Section 1 detects a predetermined cooking temperature, and a timing circuit that measures at least the period during which the boiling control means is performing the boiling operation, and the total time is a111 hours. A time correction means is provided for correcting the boil detection time corresponding to the same amount of cooked rice set in the memory based on the above.

(Function) In the present invention having such a configuration, when the rice cooking operation is started, the time measurement circuit starts measuring time. When the first sensor detects a predetermined temperature rise, the amount of cooked rice is determined based on the time measured by the clock circuit at that time. Then, the time for boiling detection corresponding to the amount of cooked rice is retrieved from the memory, and the rate of temperature rise is determined from that time and the temperature change detected by the second sensor. Boiling is detected when the rate of temperature rise falls below a rate of temperature rise determined according to the amount of cooked rice. Based on the amount of cooked rice determined to be boiling detected, the amount of heating by the rice cooking heater is controlled to decrease. When the first sensor detects a predetermined cooking temperature, the boiling operation is stopped.

Further, the timer circuit measures at least the time period during which the boiling operation is performed. Then, based on the measured time, the time for boiling detection corresponding to the same rice cooking amount set in the memory is corrected, and the temperature increase rate for the next rice cooking is determined based on this corrected time, and the boiling detection time is calculated based on this corrected time. It will be done.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a rice cooker body, which is composed of an outer case 3 and an inner case 4 connected by an upper frame 2, and a rice cooking heater 5 is provided at the inner bottom of the inner case 4. A heat insulating heater 6 is provided on the side.

7 is a rice cooker removably housed in the inner case 4;
A cup-shaped heat sensitive part 8 is provided in the inner case 4 so as to be in elastic pressure contact with the outer bottom of the pot 7. This pot 7 stores rice 9 and water 10.

A pot temperature sensor 11, which is a first sensor for detecting the temperature of the pot, is enclosed within the heat-sensitive section 8 by a heat-conductive mold member 12.

Reference numeral 13 denotes an outer lid that is pivotally installed to open and close the upper opening of the vessel main body 1. This outer lid 13 has a hollow structure and is equipped with a steam vent 14. A heat-retaining heater 6 is provided.

Reference numeral 15 denotes a cylindrical stud provided at the center of the lower surface of the outer lid 13. An inner lid 17 is suspended from the stud 15 via a bushing 16, and the inner lid 17 has a packing 18 on the outer periphery. However, the upper opening of the pot 7 can be elastically closed.

This inner lid 17 is elastically pressed against the upper opening of the pot 7 through a bushing 16 made of an elastic member such as silicone rubber, and is kept in a sealed state by a gasket 18, so that the steam pressure inside the pot 7 is maintained. If the steam pressure becomes too high, the steam pressure causes the inner lid 17 to be pushed up against the pressure of the bush 16, and the steam is released from the gap between the inner lid 17 and the pot 7. In this case, a stainless steel spring or the like may be used instead of the bush 16.

Reference numeral 19 denotes a cup-shaped heat-sensitive part f installed at the lower end of the stud] 5 so as to face the inside of the pot 7, and inside the heat-sensitive part 19 there is a lid which is a second sensor for detecting the air temperature in the pot 7. A sensor 20 is enclosed in a heat conductive mold member 21.

Reference numeral 22 denotes an electronic circuit unit provided at the bottom of the main body 1, which performs input control of the rice cooking heater 5 and the heat-retaining heater 6 based on the humidity detection information of the pot temperature sensor 11 and the lid sensor 20, etc. ing.

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

Further, the rice cooking heater 5 is connected to the power source 31 via a normally open contact 35a of a relay 35. The heat-retaining heater 6 is connected in parallel to the normally open contact 35a of the relay 35 via a bidirectional three-terminal thyristor 36.

The pan temperature sensor 11 and the lid sensor 20 are connected to the input terminals of the microcomputer 34, and the output terminals thereof are connected to a relay drive circuit 37 for controlling the energization of the coil 35c of the relay 35 and for driving and controlling the thyristor 36. A thyristor drive circuit 38 is connected thereto. 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 the main body of the control unit, and a memory provided with a memory for temporarily storing data processed by the microprocessor 41, a memory for storing various setting data, etc. 42, a clock circuit 43 for measuring time, a human power circuit 44 with an A/D conversion function for inputting and controlling signals from each of the sensors 11 and 20, and an output circuit 45 for outputting a control signal to the heater drive circuit. ing. The memory 42 stores, for example, a level corresponding to a time t2 for boiling detection corresponding to a small amount, a medium amount, and a large amount of rice to be cooked, and the relationship between the level and time for setting this time t2. There is a set table. This table has -3 to +3 for small, medium, and large amounts, respectively.
For example, in small quantities, level -3
is 16 seconds, level-2 is 32 seconds, level-1 is 48 seconds,
Level O is 64 seconds, Level 1 is 80 seconds, Level 2 is 96 seconds.
second, level 3 corresponds to 112 seconds, and at medium doses, level -3 is 96 seconds, level -2 is 112 seconds, level -1 is 128 seconds, level O is 144 seconds, level 1 is 16 seconds.
0 seconds, level 2 corresponds to 176 seconds, level 3 or 192 seconds, and in large quantities, level -3 is 160 seconds, level -2 is 176 seconds, level -1 is 192 seconds, level 0 is 208 seconds, Level 1 is 224 seconds, Level 2 is 240 seconds,
Level 3 is set corresponding to 256 seconds.

A program is set in the microprocessor 41 to perform control based on the flowcharts shown in FIGS. 4 to 11.

Fig. 4 shows the rice cooking control. First, the steaming control is performed, and when the steaming is finished, the regular rice cooking, that is, the rice cooking operation, is performed. When the end of the rice cooking is detected, the regular rice cooking is finished and the rice is cooked evenly. When the rice-cooking operation is finished, the rice-cooking side -10= control is completed.

The water-boiling control is performed based on FIG. 5. That is, the relay drive circuit 37 is controlled to drive the relay 35 and turn on the rice cooking heater 5. At the same time, the clock circuit 43 is caused to start measuring time.

Then, after 2 minutes have passed, the rice cooking heater 5 is turned off.

When another 6 minutes pass in this state, the rice cooking heater 5 is turned on again, and when 1 minute has passed, the rice cooking heater 5 is turned off.
F. When another 6 minutes elapse in this state, the hot cooking control is ended.

That is, the boiling control is performed for 15 minutes, and the water temperature is raised to a certain extent to increase the water absorption amount of the rice 9 to 25% or more.

The main rice cooking control is performed based on FIG. 6.

That is, the relay drive circuit 37 is controlled to drive the relay 35 and turn on the rice cooking heater 5.

Then, capacity determination processing is performed. (Capacity determining means) When this capacity determining process is completed, the detected temperature T of the lid sensor 20 is
Wait until the temperature reaches 1290°C, and when the temperature reaches 1590°C, boiling detection processing is performed. (Boiling Detection Means) When this boiling detection is completed, input control, ie, heating amount control during boiling, is performed. (Boiling control means) When the pot temperature sensor 11 detects a predetermined cooking temperature, for example 120° C. or higher, it is determined that the cooking has ended and the main cooking is ended.

The capacity determination process in this main rice cooking control is performed based on FIG. 7. First, the time t is input to the clock circuit 43.

Start the measurement. After that, the lid sensor 20 is set to 15deg.
Wait until the temperature rise is detected. Lid sensor 20 is 15d
When the temperature rise of eg is detected, the timing circuit 43 at that time
The measured time t1 is read.

If tl is 4 minutes and 20 seconds, it is determined that the amount of cooked rice is small. Further, if 4 minutes 20 seconds≦t1×6 minutes 20 seconds, it is determined that the amount of cooked rice is medium.

Further, if 6 minutes and 20 seconds≦t, it is determined that the amount of cooked rice is large.

Further, the boiling detection process in the main rice cooking control is carried out based on FIG. 8. This is done by referring to a table based on the rice cooking amount determined by the level and capacity stored in the memory 42 and calling up the time t2 for boiling detection, and when the rate of increase in temperature detected by the pot temperature sensor 11 is 5 deg. It is checked whether the temperature has reached 5 deg or less/t 2 or not, and when it is detected that it has become 5 deg or less/t 2, it is determined that boiling detection has ended. Further, the temperature detected by the pan temperature sensor 11 at this time is set in the memory 42 as the reference temperature 6T.

Further, manual control in the actual rice cooking control is performed based on FIG. 9. First, check whether the amount of rice cooked is set to a small amount course. Then, for a small-volume course, the heating operation is performed by reducing the electricity supply rate to the rice cooking heater 5 to 1/3 of the previous rate. This turns off the normally open contact 35a of the relay 35,
Instead, the thyristor drive circuit 38 controls the conduction phase angle of the thyristor 36.

Subsequently, the detected temperature T of the pan temperature sensor 1 is T≧S T +
2 Check whether it is d6g or not, T≧S T
When the temperature reaches +2 degrees, the energization rate to the rice cooking heater 5 is reduced by 1/
The temperature is further lowered to 4 and a heating operation is performed. Also, T≧S T
When the temperature does not reach +2d6g, the energization rate to the rice cooking heater 5 is further reduced to 1/4 after 5 minutes have elapsed, and the heating operation is performed.

In addition, if it is not a small quantity course, that is, if it is a medium quantity or large quantity course, the electricity supply rate to the rice cooking heater 5 will be reduced to 4/7 of the previous rate.
heating operation is performed.

Subsequently, the detected temperature T of the pot temperature sensor 11 is T≧ST+2d.
Check whether it is eg or not, T≧S T + 2
When the temperature reaches deg, the energization rate to the rice cooking heater 5 is further reduced to 1/3 to perform a heating operation. Also, T≧ST+2deg
If this is not the case, after 5 minutes have elapsed, the energization rate to the rice cooking heater 5 is further reduced to 1/3 and the heating operation is performed.

Further, the cooked rice detection process in the main rice cooking control is performed based on FIG. 10. First, check whether the temperature T detected by the pot temperature sensor 11 is T≧ST+5deg, and if T≧ST+5d2g, turn off the rice cooker heater 5.
Control. Then, it is checked whether T≧ST+7deg, and when T≧ST+7deg, the cooking detection is ended and the process moves to the next unevenness operation. Also, T≧ST+
When the temperature does not reach 7deg, after 1 minute has passed, the energization rate to the rice cooking heater 5 is reduced to 1/3 and the heating operation is performed again.

When the detected temperature T of the pot temperature sensor 11 reaches 12120°C, the cooking detection is finished and the rice cooking heater 5 is set to 0FFL.
Move on to the next uneven motion.

This uneven operation is performed for about 13 minutes, for example, and in the middle, the rice cooking heater 5 is operated several times for a short period of time at 100% energization rate to perform double cooking. Note that when the uneven operation is finished, the heat-retaining operation by the heat-retaining heater 6 is started.

FIG. 11 shows a setting process constituting the time correction means. In this process, when boiling detection is completed due to the temperature increase rate becoming 5 deg or less/12, the timer circuit 43 starts measuring time t3.

After that, when the cooking is detected, the time t3 measured by the timer circuit 43 is read and stored in the memory 42.

Then, this measurement time t3 is t3 minus 2 minutes, so 2 minutes≦t3
6 minutes, 6 minutes≦t3, 8 minutes, 8 minutes≦t3<1
Check 2 minutes, t, ≧12 minutes. If t3 - 2 minutes, the adjustment value is set to level 12, if 2 minutes ≦ t3 - 6 minutes, the adjustment value is set to 1 level, and if 6 minutes ≦ t3 <8 minutes, the adjustment value is set to level 0, and if t3 < 8 minutes, the adjustment value is set to level 8. If minutes≦t3<12 minutes, the adjustment value is + lebel; if t, ≧12 minutes, the adjustment value is +
Level 2.

Subsequently, the adjustment value obtained in this way is added to the level of the boiling detection time t2 used this time, and the level of the boiling detection time t2 to be used next time when cooking rice is set.

This set value becomes valid if rice is cooked with the same amount of rice within 72 hours, but if rice is not cooked even after 72 hours, the boiling detection time t2 to be used next time is set. Change the level to 0 level. Also, when the amount of rice to be cooked next time is different from the amount of rice to be cooked this time, the level is changed to 0 level.

In this embodiment having such a configuration, when a predetermined amount of rice 9 and water 1o are placed in the rice cooker pot 7 and rice cooking is started, first, a soaking operation is performed for 15 minutes. Due to this boiling operation, more than 25% of water is absorbed into the rice 9.

When the cooking is finished, the main cooking, that is, the rice cooking operation is started. In this actual rice cooking, first, the time t during which the temperature detected by the pot temperature sensor 11 increases by 15 degrees from the start of rice cooking.
1 is measured. Based on this total 1llj time t1, it is determined whether the amount of cooked rice is small, medium, or large.

After that, when the temperature T detected by the lid sensor 20 becomes 90° C. or higher, boiling detection is started. In this boiling detection, a time t2 for boiling detection is retrieved by referring to a table based on the amount of cooked rice determined to be at the level stored in the memory 42. For example, if the level is "0" and the amount of cooked rice is medium, the boiling detection time t2 = 144 seconds is called.

When the temperature increase rate becomes 5 degrees or less/t2, 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.

Further, the time measurement circuit 43 starts measuring time t.

When the boiling detection ends, heating control of the rice cooking heater 5 is started according to the amount of cooked rice, and the boiling operation is continued. That is, when the amount of rice is small, the energization rate to the rice cooking heater 5 is reduced to 1/3, and furthermore, the detected temperature T of the pot temperature sensor 11 is T≧S T
When the temperature reaches +2 degrees or 5 minutes have elapsed, the energization rate to the rice cooking heater 5 becomes 1/4. In addition, when the amount of rice is medium or large, the energization rate to the rice cooking heater 5 becomes 4/7, and the temperature T detected by the pot temperature sensor 11 is T≧S T + 2 d.
eg, or when 5 minutes have elapsed, the energization rate to the rice cooking heater 5 becomes 1/3.

Then, the detected temperature T of the pan temperature sensor 11 is T≧ST15de
When the temperature reaches 0g, the rice cooking heater 5 is set to 0FFL, and when T≧ST+7deg is reached within one minute thereafter, it is detected that the rice has been cooked and the boiling operation is ended. Also, within 1 minute, T≧ST +7 de
When the temperature does not reach g, the rice cooking heater 5 is turned on again with the energization rate of 1/3.
When the temperature reaches 12120℃, boiling is detected and the boiling operation ends.

When the cooking is detected, the timing circuit 43 finishes measuring the time t, and stores this measured time t3 in the memory 42.
to be memorized. Moreover, when the cooking detection -18= is performed, the uneven operation is performed after that, and this uneven operation is performed for about 13 minutes. In this uneven operation, the rice is cooked twice by the rice-cooking heater 5, and when the uneven operation is finished, the process shifts to a warming operation.

The above operation can be shown in a graph as shown in FIG. In FIG. 12, a solid line graph a indicates the temperature detected by the pot temperature sensor 11, and a dotted line graph b indicates the temperature detected by the lid sensor 20.
The detected temperature is shown, and the shaded part of the rice cooker heater shows that it is energized.

Further, when the measured time t3 is stored in the memory 42 by the cooking detection, the adjustment value level is determined depending on how long the time t3 is. For example, if the time is t3 or 8 minutes and 30 seconds, the adjustment value + rubel can be determined. And this time, if the level is "0" for the amount of cooked rice or medium amount, the level for determining the time t2 for the next boiling detection is 0+1, which is +Level. In other words, this means that the temperature when boiling was detected this time was slightly too low, so the level was raised by +1 to raise the temperature when boiling was detected next time.

Therefore, when the next rice cooking is done in the same amount as this time, that is, with a medium amount, and within 72 hours, the time t2 for boiling detection will be 160 seconds, compared to 144 seconds this time. Boiling detection will be performed when the temperature rise rate reaches 5 dcg or less/]60 seconds.

Note that when the next rice cooking amount is small or large, or when the next rice cooking is not started within 72 hours, the level stored in the memory 42 is changed from +level to 0 level.

In this way, it is determined whether the amount of heating is appropriate for the amount of rice cooked, based on the time t3 from when boiling is detected until the end of cooking is detected, and if it is not appropriate, boiling is performed so that the amount of heating is appropriate the next time. Since the rate of temperature rise for detection is corrected, for example, if a household always cooks a little more rice than the center of the medium amount, the rice can be cooked with an appropriate heating amount corresponding to that amount. In addition, rice can be cooked with an appropriate heating amount corresponding to the power supply voltage situation of a particular household.

Therefore, an appropriate rice cooking operation can always be performed according to the amount of rice cooked.

In addition, in the above embodiment, the temperature increase rate for boiling detection was corrected based on the time from when boiling was detected to when cooking was completed, but this is not necessarily limited to this. The total time from the start of the cooking operation to the end of the uneven cooking operation may be measured, and the temperature increase rate 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 rice to be cooked.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, and FIG. 1 is a sectional view;
FIG. 2 is a block diagram showing the main circuit configuration, FIG. 3 is a block diagram showing the configuration of the microcomputer, FIGS. 4 to 11 show control by the microprocessor, and FIG.
Figure 5 is a flowchart of the rice cooking control as a whole, Figure 5 is a flowchart of the rice cooking control, Figure 6 is a flowchart of the regular rice cooking control, Figure 7 is a flowchart of the capacity determination process in the regular rice cooking control, and Figure 8 is a flowchart of the regular rice cooking control. A flowchart of the boiling detection process, FIG. 9 is a flowchart of the inlet J control process in the main rice cooking control, FIG. 10 is a flowchart of the boiling detection process in the main rice cooking control, FIG. 11 is a flowchart of the level setting process, and FIG. 12 1 is a graph showing a detected temperature change in a rice cooking operation and an energization state of a rice cooking heater. 5. Rice cooking heater, 7. Rice cooking pot, 11. Pot temperature sensor (147th sensor), 20...
Lid sensor (second sensor), 34... microcomputer, 4 microprocessor, 42... memory, 43... clock circuit. Applicant's agent Patent attorney Takehiko Suzue = 22 =

Claims (1)

[Claims] A rice-cooking heater that heats a pot to cook rice, a first sensor that detects the temperature of the pot, a second sensor that detects the temperature of the space above the pot, a clock circuit that measures time, and this clock circuit. capacity determination means for measuring the time from when the rice cooking operation is started until the first sensor detects a predetermined temperature rise, and determining the amount of rice cooked based on the measured time; A temperature increase rate is determined from a memory in which a time for detection is set, a time for boiling detection recalled from the memory based on the amount of cooked rice determined by the capacity determining means, and a temperature change detected by the second sensor. boiling detection means detects boiling when the rate of temperature rise becomes equal to or less than a temperature rise rate determined according to the amount of cooked rice; and the capacity determination means determines that boiling is detected by the boiling detection means. Boiling control means that controls a reduction in the amount of heating by the rice-cooking heater based on the amount of cooked rice, and then stops the boiling operation when the first sensor detects a predetermined cooking temperature, and at least the boiling control means that uses the timing circuit A time correction means is provided for measuring the time during which the means performs the boiling operation, and for correcting the time for boiling detection corresponding to the same amount of cooked rice set in the memory based on the measured time. A rice cooker featuring: