JPH07284444A - Rice cooker - Google Patents

Abstract

PURPOSE:To prevent abnormal heating of a pot accurately because of degrading in the accuracy of a pot sensor. CONSTITUTION:When a detection temperature Tf of a lid sensor 31 reaches about 90 deg.C during the cooking of rice, the detection of boiling is started by a boiling detection means 6. If a temperature rising rate slows down in the detection temperature Tf of the lid sensor, the setting of the boiling detection temperature STf is carried out. Thereafter, an abnormality judging means 62 compares the detection temperature Tn of a pot sensor 13 with the boiling detection temperature STf. When the detection temperature Tn of the pot sensor 13 is lower by a specified temperature than the boiling detection temperature STf, the temperature detection accuracy of the pot sensor 13 is determined to be worse to decrease heating level of an induction coil. Thus, when the boiling detection temperature STf is set, the temperature detection accuracy of the pot sensor 13 is judged thereby enabling the preventing of abnormal heating of the pot.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice cooker that cooks rice by heating the pot by means of pot heating means, and particularly when the temperature detection accuracy of the pot temperature detecting means for detecting the outer surface temperature of the pot deteriorates. For rice cookers with improved

[0002]

2. Description of the Related Art Conventionally, this type of rice cooker has a pot in which rice, which is to be cooked, and water are contained in a pot, and the top opening of the container is closed by a lid, and then the pot temperature is detected. The heating amount of the pan heating means for heating the pan is controlled based on the temperature detected by the pan sensor serving as the temperature detecting means. In the case of a rice cooker with such a structure, the pot temperature sensor is provided in contact with the outer surface of the pot, so rice or rice may be caught between the pot sensor and the pot, or water droplets may adhere, or
When the accuracy of the pan sensor is deteriorated due to the deformation of the pan sensor and the pan, and the change in the dimensional accuracy over time, the temperature detected by the pan sensor is detected as low even though the pan is hot during rice cooking. There is a risk that the temperature fuse may operate by continuing heating without detecting the raised temperature, or in the worst case, the rice cooker body may be deformed or melted due to abnormal heating.

In order to avoid such a situation, if the rice cooking continues for an abnormally long time than usual, the pot heating means is stopped, and the temperature detected by the pot sensor is higher than usual even after a lapse of a predetermined time after starting the rice cooking. If the temperature is too low, the pot heating means is stopped, and the temperature of the steam generated from the pan during rice cooking is detected by another temperature sensor that is a steam temperature detection means provided in a non-contact state with the pan When the pan sensor does not detect the cooked temperature even after a lapse of a predetermined time, the pan heating means is stopped, temperature sensors are arranged at various places of the main body, and when any one of the temperature sensors detects an abnormal temperature, Conventionally, various countermeasures have been known, such as stopping the pot heating means and performing a series of temperature control using an infrared radiation temperature sensor capable of detecting the temperature in a non-contact state with the pot, instead of the pot sensor.

[0004]

The respective countermeasures for avoiding the abnormal heating of the pot have the following drawbacks.
In the countermeasure method, it is necessary to set the stop time of the pan heating means to be longer than at least the time when the maximum amount of rice can be cooked, and when the amount of rice is small or the rice is cooked empty,
There is a risk that the main body will be deformed or melted before the operation of the pan heating means is stopped due to the abnormality determination. As a countermeasure, the abnormal heating of the pot is erroneously detected even if the temperature detection accuracy is somewhat poor due to the variation of the pot sensor, or the same abnormality is detected when the thermistor which is the pot sensor is disconnected. Therefore, accurate detection cannot be performed. Depending on the amount of water and the amount of cooked rice, the countermeasure method may cause variations in the boiling duration after steam is generated, or when boiling rice or brown rice, the boiling duration is longer than when cooking white rice. Therefore, in consideration of at least these points, the stop time of the pot heating means must be set longer than the maximum boiling duration time. In this case, there is a risk that the main body may be deformed or melted before the operation of the pan heating means is stopped due to the abnormality determination.
Further, in the countermeasure method, a temperature sensor for safety is additionally required in addition to the control of rice cooking and heat retention, which complicates the structure and control of the temperature sensor and deteriorates the assemblability. further,
With the countermeasure method, an infrared radiation temperature sensor is provided in a non-contact state with the pan, so it is difficult to detect the temperature with high accuracy, and the cooked rice will be slightly burnt or underheated, and the cooked state will have large variations. .

In view of the above circumstances, the present invention reliably prevents abnormal heating of the pan due to deterioration of the accuracy of the pan temperature detecting means with a simple structure even when the amount of cooked rice changes or when the rice is cooked empty. An object of the present invention is to provide a rice cooker capable of cooking rice that can be eaten as desired.

[0006]

A rice cooker according to claim 1 is provided with a pan for containing cooked rice, a pan temperature detecting means for detecting the temperature of the pan, and a non-contact state with the pan. Steam temperature detecting means for detecting the temperature of steam generated from the pan during cooking rice, pan heating means for heating the pan, and heating the pan based on the temperatures detected by the pan temperature detecting means and the steam temperature detecting means. The pot heating control means for controlling the heating amount of the means, and the boiling detection is started when the temperature detected by the steam temperature detection means reaches a predetermined temperature after the start of rice cooking, and the temperature rise rate of the temperature detected by the steam temperature detection means. Based on the boiling detection means for detecting the boiling of the pot, after the boiling detection by the boiling detection means, the temperature detected by the pot temperature detection means is a predetermined temperature lower than the boiling detection temperature of the steam temperature detection means at the time of boiling detection. Or If the one in which includes an abnormality judging means for reducing or stopping the heating of the pan heating means.

The rice cooker according to a second aspect of the present invention includes a pan for containing the rice to be cooked, a pan temperature detecting means for detecting the temperature of the pan, and the pan provided in a non-contact state with the pan during cooking. The steam temperature detecting means for detecting the temperature of the steam generated from the pan, the steam temperature detecting means mounting part for mounting the steam temperature detecting means, the mounting part heating means for heating the steam temperature detecting means mounting part, and the pan. Pan heating means for heating, pan heating control means for controlling the heating amount of the pan heating means based on the temperatures detected from the pan temperature detecting means and the steam temperature detecting means, and detection of the steam temperature detecting means after starting rice cooking When the temperature reaches a predetermined temperature, the boiling detection is started, and the boiling of the pot is detected based on the temperature increase rate of the temperature detected by the steam temperature detecting means, and the mounting portion heating means is operated after the boiling is detected. When the temperature detected by the pan temperature detection means or the steam temperature detection means after boiling detection by the boiling detection means and the boiling detection means is higher by a predetermined temperature than the boiling detection temperature of the steam temperature detection means at the time of boiling detection, And a nonuniformity shift determination means for reducing or stopping the heating amount of the pan heating means.

[0008]

According to the structure of claim 1, when the temperature detected by the steam temperature detecting means reaches a predetermined temperature during rice cooking, the boiling detecting means starts the boiling detection. When the steam temperature reaches a stable boiling state and the temperature increase rate of the temperature detected by the steam temperature detecting means slows down, it is determined that boiling has been detected at this point, and the boiling detection temperature is set. After that, the abnormality determination means compares the temperature detected by the pot temperature detection means with the boiling detection temperature, and if the temperature detected by the pot temperature detection means is lower than the boiling detection temperature by a predetermined temperature, the temperature detection accuracy of the pot temperature detection means is poor. Judging from the above, the heating amount of the pan heating means is reduced or stopped as compared with the case where the temperature detection accuracy of the pan temperature detection means is good.

According to the second aspect of the invention, when the temperature detected by the steam temperature detecting means reaches a predetermined temperature during rice cooking, the boiling detecting means starts the boiling detection. Then, if the steam temperature reaches a stable boiling state and the temperature rise rate of the detected temperature of the steam temperature detecting means is slowed down, it is determined that boiling is detected at this point, and the boiling detection temperature is set. , Heating the steam temperature detecting means mounting portion via the mounting portion heating means. Thereafter, the unevenness shift determination means compares the temperature detected by the pan temperature detection means or the steam temperature detection means with the boiling detection temperature. At this time, if the pan temperature detecting means or the detecting means of the steam temperature detecting means is higher than the boiling detection temperature of the steam temperature detecting means by a predetermined temperature, the heating amount of the pan heating means is reduced or stopped to shift to unevenness.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. First, the overall structure of the rice cooker will be described with reference to FIGS. 1 and 2. In FIG. 1, reference numeral 1 is a main body of the rice cooker having an open top surface, which is an inner frame 2 serving as a pot housing portion.
And an outer frame 3 made of plastic, and a frame body 4 connecting the inner frame 2 and the outer frame 3 at the upper part. Reference numeral 5 denotes a pot for holding a bottomed tubular rice to be cooked which is accommodated in the inner frame 2. The pot 5 is made of ferritic stainless steel or enameled steel sheet made of magnetic metal material, and the inner surface thereof is not A fluororesin coating layer having adhesiveness is formed. In addition, a tapered inclined portion 6 is formed on the side portion of the pan 5 at an angle of 10 ° to 45 ° with respect to the vertical direction, and a flange portion 7 formed at the upper end is in contact with the upper portion of the frame body 4. In contact with each other, the pot 5 is supported in a suspended state.

On the outer side of the inner frame 2, there are provided an upper coil 8 arranged to face the upper portion of the inclined portion 6 and a lower coil 9 arranged to face the lower portion of the inclined portion 6 and the bottom portion of the pot 1. By these upper coil 8 and lower coil 9,
An induction coil 10 is constructed as a pan heating means for heating the pan 5 by electromagnetic induction. Further, 11 is a coil base made of FR-PET (glass fiber reinforced-terephthalic acid polyester) or the like. This coil base 11 is an induction coil 10.
It is attached and fixed so as to cover the outside of. A ferrite core 12 that prevents leakage magnetic flux from the induction coil 10 is provided outside the coil base 11.

Reference numeral 13 denotes a pan sensor which is a pan temperature detecting means provided in contact with the bottom surface of the pan 5. This pan sensor 13 has a thermistor 14 for detecting the outer surface temperature of the pan 5,
The inner frame 2 is provided so as to be retractable in an opening 15 formed in the central bottom portion of the inner frame 2. The pan sensor 13 is urged upward by the spring 16, and in the state without the pan 5 shown in FIG. 2, the upper part of the pan sensor 13 abuts on the inclined end 17 of the opening 15 so that the pan sensor 13 moves upward. To regulate the movement to. Also, 18
Is a heating control board provided in the lower part of the container body 1 and is provided with various circuits described later. An intake port 19 and an exhaust port 20 are provided on the side portion and the bottom portion of the outer frame 3, respectively, and a blower 21 is provided inside the device body 1 so as to face the intake port 19 and cool air is blown by the blower 21. The induction coil 10 and the heating control board 18 are cooled by being introduced into the main body 1. Reference numeral 22 is an operation board provided on the front side of the container body 1.

Reference numeral 25 denotes a lid body which covers the upper portion of the container body 1 so as to be openable and closable. The lid 25 includes, for example, an outer lid 26 made of polypropylene resin, and an inner lid 27 which is a vapor temperature detecting means mounting portion formed by anodizing an aluminum material attached while forming a space below the outer lid 26. A steam port 29, which is constituted by an outer lid cover 28 provided on the outer peripheral side of the outer lid 26 and discharges the above generated from the pot 5 to the outside, is provided at substantially the center of the lid body 25. On the back surface of the inner lid 27, there is provided a lid heater 30 as a mounting portion heating means composed of a cord heater for heating the inner lid 27, and a steam temperature for detecting the temperature of steam generated from the pan 5 during rice cooking. Lid sensor 31 as a detection means
Are provided in a non-contact state with the pan 5.

Next, the structure of the operation panel 32 provided on the upper surface of the operation board 22 will be described with reference to FIG. In the figure, 33 is a process display lamp that displays each process of rice cooking and heat retention, 34 is an LCD display unit that displays an error display, etc. These process display lamp 33 and LCD display unit
The display means 35 is constituted by 34. In addition, the operation panel 32
In the lower part of the, rice cook start switch for instructing the rice cook start
36, a heat retention start switch 37 that inputs a heat retention start instruction,
An operating means 39 is provided which comprises an off switch 38 for stopping the operation being executed.

FIG. 4 shows the structure of the electric circuit.
In the figure, reference numeral 41 is a control means composed of a microcomputer mounted on the heating control board 18, which is provided with a CPU, ROM, RAM and the like (not shown), as well as a clock means 42 and a storage means 43 as well known. There is. The input ports of the control means 41 are respectively connected to A / D converters 44,
The lid sensor 31 and the pan sensor 13 are connected via 45, and the temperature detection data of the pan 5 and the inner lid 27 are input to the control means 41. Further, the rice cooking start switch 36, which constitutes the operation means 39, is connected to the input port of the control means 41.
The heat retention start switch 37 and the off switch 38 are connected. On the other hand, a heater drive means 46 having a switch means such as a triac is connected to the output port of the control means 41, and the lid heater 30 is controlled to be turned on and off through the heater drive means 46. Further, as an induction heating device 47 for electromagnetically heating the pot 5, a high frequency current generating means 48 for supplying a predetermined high frequency current based on an output signal from the control means 41 and a high frequency current value from the high frequency current generating means 48 are provided. An output adjusting means 49 that controls the electric current to the induction coil 10 is provided which is variable, and when a predetermined high frequency current is supplied to the induction coil 10, an alternating magnetic field is generated in the induction coil 10 to induce induction. Eddy currents are generated in the bottom portion of the pot 5 facing the coil 10 and in the upper and lower portions of the inclined portion 6, respectively, and the eddy currents are converted into Joule heat to heat the pot 5. Reference numeral 50 is a display driving means connected to the output port of the control means 41, and the display on the display means 35 is controlled via the display driving means 50.

FIG. 5 is a block diagram showing the processing procedure of the control program stored in the storage means 43 of the control means 41. In the figure, 61 is a boiling detection means for detecting boiling of the pan 5 based on the temperature increase rate of the temperature Tf detected by the lid sensor 31. In the boiling detection means 61, the detection temperature Tf of the lid sensor 31 after the start of rice cooking is around 90 ° C., preferably 90 ° C. ±.
When the temperature reaches 10 ° C., the boiling detection for detecting the temperature increase rate of the detected temperature Tf is started.
When it slowed to 0 ° C to 2 ° C in 0 seconds, it was judged that steam was generated from the pan 5 and the steam temperature reached a stable boiling state,
The detected temperature Tf at this point is set to the boiling detection temperature ST hereafter.
The setting is stored as f. Further, the boiling detection means 61 is a lid heater regardless of the determination result of the abnormality determination means 62 described later.
It has a function of controlling the lid heating control means 63 so as to energize 30 at 100%.

Reference numeral 62 denotes an abnormality determining means for determining the temperature detection accuracy of the pan sensor 13, which is the boiling detection temperature S after the boiling detection by the boiling detection means 61.
When the temperature is lower than Tf by a predetermined temperature, it is judged that the temperature detection accuracy of the pan sensor 13 is poor, and the heating amount of the induction coil 10 is detected by the pan heating control means 64 and the temperature detection accuracy of the pan sensor 13 is good. It is reduced or stopped more than when it is judged. Further, 65 is based on a comparison between the temperature Tn detected by the pan sensor 13 or the temperature Tf detected by the lid sensor 31 and the boiling detection temperature STf after judging the temperature detection accuracy of the pan sensor 13 by the abnormality judgment means 62. It is an unevenness shift determination means for determining whether or not to shift to the spotty after cooking rice. After the boiling detection by the boiling detection means 61, the unevenness transition determination means 65 has a detection temperature Tn of the pan sensor 13 or a detection temperature Tf of the lid sensor 31 higher than the boiling detection temperature STf of the lid sensor 31 at the time of boiling detection. In this case, the cooked rice is switched to the Mururashi, and the heating amount of the induction coil 10 is reduced or stopped via the pan heating control means 64 compared with the cooked rice. Reference numeral 64 is an induction coil 10 based on the temperature Tn detected by the pan sensor 13 and the temperature Tf detected by the lid sensor 31 in response to commands from the abnormality determination means 62 and the unevenness transition determination means 65.
The pan heating control means 63 for controlling the heating amount of the lid heater 63 is based on the detection temperature Tn of the pan sensor 13 and the detection temperature Tf of the lid sensor 31, and the lid heater is instructed by the boiling detection means 61 and the unevenness shift determination means 65. A lid heating control means for controlling the heating amount of 30.

Next, regarding the rice cooker having the above-mentioned configuration, an outline of each control from rice cooking to the spotty will be described with reference to temperature changes of the pan sensor 13 and the lid sensor 31, and disconnection of the induction coil 10 and the lid heater 30. Description will be given based on the graph of FIG. 6 and the flowcharts of FIGS. 7 and 8. In the graph of FIG. 6, Tn represents the temperature detected by the pan sensor 13, and
Tf indicates the temperature detected by the lid sensor 31.

After the rice to be cooked and the water are stored in the pan 5, the pan 5 is stored in the inner frame 2 and the lid 25 is closed. And
Press the rice cooking switch 36 to start rice cooking operation,
After the predetermined hot water cooking process, the main cooked rice in which the induction coil 10 shown in the flowchart of FIG. 7 is energized with 100% output starts (step S1). At this time, the lid heater 30 is in a power-off state, and the detection temperature Tf of the lid sensor 31 gradually increases depending on the temperature of the steam generated from the pan 5. On the other hand, as for the detection temperature Tn of the pan sensor 13, if the normal pan 5 and the pan sensor 13 are in good contact with each other, the heat from the pan 5 is directly transmitted to the pan sensor 13 and the detected temperature Tf of the lid sensor 31. Although the rising of the pan 5 becomes steep, the heat from the pan 5 is less likely to be transferred to the pan sensor 13 as the contact state between the pan 5 and the pan sensor 13 deteriorates, and the rising of the detected temperature Tn also becomes gentle. Here, the boiling detection means 61 determines whether or not the detection temperature Tf of the lid sensor 31 provided in a non-contact state with the pan 5 has reached around 90 ° C. (step S2: in the figure, however. 90 ° C.), when the detected temperature Tf reaches around 90 ° C., the boiling detection in the pan 5 is started (step S).
3). Then, the process proceeds to step S4, where the temperature rise rate is 0 in 90 seconds based on the detected temperature Tf of the lid sensor 31.
It is judged by the boiling detection means 61 whether or not the temperature has dropped to 2 ° C or lower, and when the temperature rise rate slows to 0 to 2 ° C / 90 seconds, steam is generated from the pan 5 and the boiling temperature reaches a stable boiling state. It is determined that the temperature is detected and the temperature Tf detected by the lid sensor 31 at this time is stored and set as the boiling detection temperature STf (step S5), and the lid heating control means 63 is operated by the instruction from the boiling detection means 61. The heater 30 is energized with an output of 100% to heat the inner lid 27 (step S6). In the step S2, the boiling detection by the boiling detection means 61 is preferably started when the detection temperature Tf of the lid sensor 31 reaches around 90 ° C. This is because if the detection temperature Tf at the start of boiling detection is set to less than about 90 ° C., the temperature increase rate of the detection temperature Tf becomes dull due to factors such as a low input voltage or an extremely large amount of water with respect to rice. If so, the boiling detection temperature STf may be detected lower than it actually is, and if the boiling detection is started at the detection temperature Tf of about 90 ° C. or higher which can be a normal use environment, the boiling of the pot 5 is surely performed. The state can be detected.

Then, the process goes to step S7 shown in the flow chart of FIG.
13. Determine the temperature detection accuracy. That is, after the boiling detection means 61 sets the value of the boiling detection temperature STf, the abnormality determination means 62 compares the boiling detection temperature STf with the detection temperature Tn of the pan sensor 13, and the detection temperature Tn is the boiling detection temperature STf- If the temperature is 10 ° C or higher, it is determined that the temperature detection accuracy of the pan sensor 13 is normal, and then step S
At 8, the induction coil 10 is energized with an output of 60% which is a normal rice cooking control. On the other hand, if the detected temperature Tn is less than the boiling detection temperature STf-10 ° C in step S7, it is determined that the temperature detection accuracy of the pan sensor 13 is abnormal, and then the induction is performed in step S9. The coil 10 is energized with an output of 30%, which is a heating amount reduced to about half that in the normal state, and an error is displayed through the LCD display section 34 to notify the user of the abnormality of the pan sensor 13. In addition,
In this step S9, the heating amount of the induction coil 10 may be stopped, and when the heating amount of the induction coil 10 is reduced, abnormal heating of the pan 5 due to deterioration of the temperature detection accuracy of the pan sensor 13 is prevented beforehand. it can. Further, conventionally, after the lid sensor 31 detects boiling, the temperature detection accuracy of the pan sensor 13 was evaluated with reference to a predetermined fixed temperature when the pan sensor 13 should be boiling at the normal time. In the case where the boiling temperature is low, although the temperature detection accuracy of the pan sensor 13 is normal, the detection temperature Tn of the pan sensor 13 is low and it is erroneously determined to be abnormal. In the abnormality determination in step S7 of the example, the boiling detection temperature STf of the lid sensor 31 is used as a reference for the evaluation. Therefore, even if the boiling temperature changes due to the influence of atmospheric pressure or the like, the pan sensor 13 can be reliably operated.
The temperature detection accuracy of can be determined. Moreover, pan 5
In consideration of the heat conduction and the like, STf−10 ° C., which is slightly lower than the boiling detection temperature STf, is used as the criterion for the determination, and thus the factor of the erroneous determination can be further removed.

When the abnormality determination means 62 completes the abnormality determination, the unevenness shift determination means 65 executes the steps S10 and S11 regardless of the temperature detection accuracy of the pan sensor 13. That is, after the boiling detection, the unevenness shift determination means 65 determines whether the temperature Tf detected by the lid sensor 31 is the boiling detection temperature STf + 10 ° C. or higher, or the detection temperature Tn of the pan sensor 13 is the boiling detection temperature STf + 20 ° C. or higher. Then, the heating amount of the induction coil 10 is substantially stopped, and the process proceeds to the subsequent unevenness (step S12). The heating amount is preferably such that the pot 5 is maintained at about 100 ° C. during the unevenness, and the heating amount of the induction coil 10 may be decreased without stopping.

As described above, if the unevenness shift determination means 65 makes the temperature Tn detected by the pan sensor 13 or the temperature Tf detected by the lid sensor 31 higher than the boiling detection temperature STf by a predetermined temperature, the unevenness shift determination means 65 shifts to unevenness. Because the pan sensor
If the temperature detection accuracy of 13 is normal, the dry-up state can be surely detected by the increase in the temperature Tn detected by the pan sensor 13 in step S11, and it is possible to shift to unevenness without trouble such as burning. Further, after the boiling is detected, the boiling detection means 61 heats the inner lid 27 through the lid heater 30, so that steam is generated from the pot 5 and the steam is generated.
While hitting 27, even if the lid heater 30 is heating, the heat is removed by the steam, and the temperature Tf detected by the lid sensor 31 is detected.
Is stable at about the boiling temperature, but when the water content in the pot 5 becomes low and the dry-up state approaches, the detection temperature Tf of the lid sensor 31 rapidly rises due to the heating by the lid heater 30. Then, as is apparent from step S10 of FIG. 8, the temperature rise of the detected temperature Tf is also used as the criterion for the uneven transfer. Therefore, even if the abnormality determination means 62 does not detect the deterioration of the temperature detection accuracy of the pan sensor 13, the unevenness transition determination means 65 replaces the detected temperature Tn of the pan sensor 13 with poor temperature detection accuracy. Since the detection temperature Tf of the lid sensor 31 is used as a reference to determine the shift to the unevenness, the temperature rise of the pan 5 is not directly captured, so some variation such as burning occurs.
While preventing abnormal heating of the pan 5 due to the deterioration of the temperature detection accuracy of the pan sensor 13, it is possible to cook rice that has no taste problem.

The amount of heat applied to the lid heater 30 after the boiling is detected is such that the temperature Tf detected by the lid sensor 31 is substantially the same as the boiling temperature when the steam generated from the pot 5 hits the inner lid 27. It is preferable to set the detection temperature Tf of the lid sensor 31 to about 120 ° C. at which the outer lid 26 does not melt when the steam is not hitting the 27. Further, in the embodiment, the abnormal condition of the pan 5 is prevented from being abnormally heated due to the deterioration of the temperature detection accuracy of the pan sensor 13 by the respective judgment conditions of the abnormal condition judging means 62 and the uneven migration judging means 65.
It is preferable to preferentially perform the determination condition by the abnormality determination means 62, because the abnormal heating can be detected early. That is, by adding the determination condition by the latter unevenness shift determination means 65, it becomes possible to finish the rice in a state in which there is no problem in taste even if the temperature detection accuracy of the pan sensor 13 is poor.

As described above, in this embodiment, in response to claim 1, boiling detection is started when the temperature detected by the lid sensor 31 reaches around 90 ° C. after the start of rice cooking, and the temperature detected by the lid sensor 31 is detected. Boiling detection means 61 for detecting the boiling of the pan 5 based on the temperature rise rate of Tf, and the boiling detection temperature of the lid sensor 31 when the detection temperature Tn of the pan sensor 13 is the boiling detection after the boiling detection by the boiling detection means 61. Since it is provided with an abnormality determining means 62 for reducing or stopping the heating amount of the induction coil 10 when the temperature is lower than STf by a predetermined temperature, the pan is based on the boiling detection temperature STf of the lid sensor 31 during boiling. When the temperature detection accuracy of the sensor 13 is poor, the heating amount of the induction coil 10 can be reduced or stopped to prevent abnormal heating of the pan 5. Therefore, the boiling detection temperature S
If Tf is set, the temperature detection accuracy of the pan sensor 13 is immediately determined based on the boiling detection temperature STf. Therefore, as in the conventional case, when the amount of cooked rice is small or the rice is cooked empty, the induction coil is used. It is possible to reliably prevent the risk that the main body is deformed or melted before the operation of 10 stops due to the abnormality determination. In this case, the temperature detection accuracy may be somewhat poor due to the variation of the pan sensor 13, or even if the pan sensor 13 is disconnected, it will not be erroneously detected, and the disconnection of the pan sensor 13 can be accurately detected, and the amount of water and the amount of cooked rice change. Also, when cooking rice for porridge or brown rice, the temperature detection accuracy of the pan sensor 13 can be reliably determined regardless of the rice cooking conditions.

According to the second aspect of the present invention, boiling detection is started when the temperature detected by the lid sensor 31 reaches around 90 ° C. after the start of rice cooking, and the temperature Tf detected by the lid sensor 31 rises. The boiling of the pan 5 is detected based on the rate, and the boiling detection means 61 for operating the lid heater 30 after the boiling is detected, and the detection temperature Tn of the pan sensor 13 or the lid sensor 31 after the boiling detection by the boiling detection means 61 When the temperature Tf is higher than the boiling detection temperature STf by the prescribed temperature, the unevenness shift determining means 65 for reducing or stopping the heating amount of the induction coil 10 is provided, so that the temperature detection accuracy of the pan sensor 13 is improved. In a good normal condition, the pan sensor that contacts the pan 5
Based on the detected temperature Tn of 13, it is possible to judge the transition to the spotty with highly accurate temperature detection, and it is possible to cook without overheating or underheating. On the other hand, the temperature detection accuracy of the pan sensor 13 is bad. At times, in order to judge the shift to the spotty based on the temperature Tf detected by the lid sensor 31 that is not in contact with the pan 5,
It is possible to cook rice that can be finally eaten while preventing abnormal heating of the pan 5. Therefore, even if the temperature detection accuracy of the pan sensor 13 is poor, the induction coil 10 is not forcibly stopped and the rice is not cooked raw, and it is possible to cook the rice in a state that can be repaired after cooking.

Further, in common with the structures of claims 1 and 2, it is not necessary to provide another temperature sensor other than the sensors 13 and 31 for cooking rice or keeping heat, so that the structure and control of the temperature sensor are complicated. There is no change and the assemblability does not deteriorate. Therefore, even when the amount of cooked rice changes or the rice is cooked empty, the pot 5 has a simple structure and the pot sensor 13 deteriorates in accuracy.
Abnormal heating can be reliably prevented.

Further, as an effect of the embodiment, since the operation panel 32 is provided with the display means 35 having the LCD display section 34 for displaying an error display and the like, when the temperature detection accuracy of the pan sensor 13 is poor. Can notify the outside to that effect, and can prompt the user to clean the container body 1 and the pan 5. In addition, the manufacturing side can easily know the cause of the poorly cooked food and can promptly implement the performance improvement.

The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the gist of the present invention.

[0029]

According to the rice cooker of the first aspect of the present invention, the pot for containing the food to be cooked, the pot temperature detecting means for detecting the temperature of the pot, and the pot provided in a non-contact state with the pot are used for cooking. Steam temperature detecting means for detecting the temperature of the steam generated from the pan, pan heating means for heating the pan, and the heating amount of the pan heating means based on the temperature detected by the pan temperature detecting means and the steam temperature detecting means And the pot heating control means for controlling the boiling point, and when the temperature detected by the steam temperature detecting means reaches a predetermined temperature after starting the rice cooking, the boiling detection is started, and the pan is based on the temperature increase rate of the temperature detected by the steam temperature detecting means. When the boiling detection means for detecting the boiling of the, the temperature detected by the pot temperature detection means after the boiling detection by the boiling detection means is a predetermined temperature lower than the boiling detection temperature of the steam temperature detection means at the time of boiling detection, Previous It is equipped with abnormality determination means that reduces or stops the heating amount of the pot heating means, and abnormal heating of the pot due to the deterioration of the accuracy of the pot temperature detection means with a simple structure even when the amount of cooked rice changes or when cooking empty Can be reliably prevented.

The rice cooker according to a second aspect of the present invention includes a pan for containing the food to be cooked, a pan temperature detecting means for detecting the temperature of the pan, and the pan provided in a non-contact state with the pan during cooking. The steam temperature detecting means for detecting the temperature of the steam generated from the pan, the steam temperature detecting means mounting part for mounting the steam temperature detecting means, the mounting part heating means for heating the steam temperature detecting means mounting part, and the pan. Pan heating means for heating, pan heating control means for controlling the heating amount of the pan heating means based on the temperatures detected from the pan temperature detecting means and the steam temperature detecting means, and detection of the steam temperature detecting means after starting rice cooking When the temperature reaches a predetermined temperature, the boiling detection is started, and the boiling of the pot is detected based on the temperature increase rate of the temperature detected by the steam temperature detecting means, and the mounting portion heating means is operated after the boiling is detected. When the temperature detected by the pan temperature detection means or the steam temperature detection means after boiling detection by the boiling detection means and the boiling detection means is higher by a predetermined temperature than the boiling detection temperature of the steam temperature detection means at the time of boiling detection, A non-uniformity transfer determination means for reducing or stopping the heating amount of the pan heating means,
Even when the amount of cooked rice changes or when cooked empty, it is possible to reliably prevent abnormal heating of the pot due to the deterioration of the accuracy of the pot temperature detection means with a simple structure, and to cook rice that can be finally eaten. You can

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a rice cooker showing an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of the same.

FIG. 3 is a plan view of a main part of the same.

FIG. 4 is a block diagram showing an electrical configuration of the same.

FIG. 5 is a block diagram showing a processing procedure of the above control program.

FIG. 6 is a graph showing temperature change and on / off control.

FIG. 7 is a flowchart of the process from rice cooking to Murashi.

FIG. 8 is a flowchart from rice cooking to Murashi.

[Explanation of symbols]

 5 Pan 10 Induction coil (pot heating means) 13 Pan sensor (pot temperature detecting means) 27 Inner lid (steam temperature detecting means mounting part) 30 Lid heater (mounting part heating means) 31 Lid sensor (steam temperature detecting means) 61 Boiling Detecting means 62 Abnormality judging means 64 Pot heating control means 65 Murashishi transfer judging means

Claims (2)

[Claims] 1. A pot for containing cooked rice, a pot temperature detecting means for detecting a temperature of the pot, and a temperature of steam generated from the pot during non-contact with the pot, which is provided in a non-contact state. Steam temperature detecting means, pan heating means for heating the pan, pan heating control means for controlling the heating amount of the pan heating means based on the temperatures detected by the pan temperature detecting means and the steam temperature detecting means, and cooked rice After starting the boiling detection at a time when the detected temperature of the steam temperature detecting means reaches a predetermined temperature, a boiling detecting means for detecting the boiling of the pot based on the temperature increase rate of the detected temperature of the steam temperature detecting means, When the temperature detected by the pot temperature detection means after the boiling detection by the boiling detection means is lower than the boiling detection temperature of the steam temperature detection means by a predetermined temperature at the time of boiling detection, the heating amount of the pan heating means is decreased. A rice cooker comprising: an abnormality determining means for stopping the ruin. 2. A pot for containing cooked rice, a pot temperature detecting means for detecting the temperature of the pot, and a temperature of steam generated from the pot during non-contact with the pot, which is provided in a non-contact state. Steam temperature detecting means, steam temperature detecting means mounting portion for mounting the steam temperature detecting means, mounting portion heating means for heating the steam temperature detecting means mounting portion, pot heating means for heating the pot, and pot temperature Boiling heating control means for controlling the heating amount of the pan heating means based on the detection temperature from the detection means and the steam temperature detection means, and boiling when the detection temperature of the steam temperature detection means reaches a predetermined temperature after the start of rice cooking. Start the detection, detect the boiling of the pot based on the temperature rise rate of the temperature detected by the steam temperature detection means, the boiling detection means for operating the mounting portion heating means after the boiling detection, the boiling detection means When the temperature detected by the pot temperature detection means or the steam temperature detection means after boiling detection by is higher by a predetermined temperature than the boiling detection temperature of the steam temperature detection means at the time of boiling detection, the heating amount of the pan heating means is changed. A rice cooker comprising: a nonuniformity shift determination means for reducing or stopping.