JP5103812B2 - rice cooker - Google Patents

Description

  The present invention relates to a rice cooker, and more particularly, to a rice cooker using a ceramic pot such as an earthen pot as an inner pot for cooking rice.

  In general, a rice cooker has a plurality of heating means such as an induction coil, a lid heater, and a side heater, and uses these heating means to automatically cook and keep warm, providing the user with the most suitable rice etc. Widely known as an instrument.

  The process of the rice cooker includes a water absorption process for absorbing sufficient water into the rice, a temperature rising process for raising the heat to cook the rice, a cooking process for cooking the rice, and a rice cooking process consisting of a subsequent uneven process, It consists of a heat retention process after the rice cooking process. In each process, the output to the heating means such as the induction coil, lid heater and side heater is controlled based on the detection signal from the center sensor, etc., and optimal process control is performed. Yes.

  Conventionally, the inner pot for cooking rice is made of metal, and for example, heating control as shown in FIG. 7 is performed. The outline of the control will be described with reference to the drawings. In the temperature raising process, the control judges the detection of the boiling temperature in step S3, and when the boiling temperature is detected, the subsequent boiling maintenance heating is performed with the output at the time of detecting the boiling temperature. Therefore, more suitable rice cooking heating can be performed (see, for example, Patent Document 1).

  By the way, the metal inner pot has a characteristic that it is easy to heat and cool, and particularly has a problem of requiring energy during the heat-retaining process because it is easy to cool after cooking. In order to compensate for the shortcomings of such a metal inner pot, the present applicant has proposed the use of a ceramic pot. In other words, ceramic products have a larger heat capacity than metal products, so the rate of temperature rise during cooking is relatively mild, and the heat storage is good, so that rice can be cooked deliciously and has a heat-retaining effect. There is an advantage that it can contribute to energy saving.

However, when the heating control of the clay pot is performed using the heating control as shown in FIG. That is, as mentioned above, the earthenware pot is preferably made of heat storage, so if the subsequent heating control is performed with the heating output at the time of detecting the boiling temperature, the temperature of the earthenware pot will be higher than the boiling temperature, especially in menus such as rice crackers with a lot of moisture. Occurred.
JP-A-6-46952

  The present invention provides a rice cooker that can prevent spillage in menus such as rice crackers with a lot of moisture by lowering the heating power step by step in the temperature raising process and the cooking process based on the signal of the lid sensor. The purpose is to do.

  In order to achieve the above object, the present invention adopts the following configuration.

  In the invention which concerns on Claim 1, the inner pot made from a ceramic, the inner case which accommodates this inner pot, the heating means which heats the said inner pot, and the lid sensor which detects the temperature of the lid body provided in the lid body And a center sensor for detecting the temperature of the inner pot provided in the rice cooker main body, a heating control means for controlling the heating state of the heating means, and an operation part having a display part, and at least a heating step in the rice cooking process In the rice cooker having the cooking process, the control of the heating control means has a control for gradually reducing the power consumption based on the signal of the lid sensor. The structure which is control from a temperature rising process to a cooking process. And by such a structure, the temperature rise of an earthenware pot is suppressed and the spilling of rice crackers etc. is eliminated.

  In the invention which concerns on Claim 3, in the said cooking process, the structure which adjusts power consumption so that the detection temperature by the said lid sensor and the detection temperature by a center sensor may become equal. And by such a structure, the cooking process control in the boiling-temperature vicinity is attained like a metal pan also in a cooking process.

  In the invention according to claim 1, a plurality of predetermined temperatures below the boiling temperature are sequentially detected by the lid sensor, and heating control is performed by sequentially decreasing the heating output in accordance with the detection. In the invention according to claim 2, the control is performed. By performing from the temperature raising process to the cooking process, it is possible to suppress the temperature rise due to the high heat storage property of the earthenware pot, and it is possible to prevent spillage in menus such as rice crackers with a lot of moisture. In addition, the control which reduces a heating output in steps means the control in a temperature rising process (temperature rising 1 process and temperature rising 2 process) and a cooking process.

  In the invention according to claim 3, in the cooking process, the heating power is adjusted so that the detection temperature of the lid sensor and the detection temperature of the center sensor are equal to each other. The cooking process can be controlled in the vicinity of the temperature, and more delicious rice crackers can be cooked.

  FIG. 1 is a longitudinal sectional view of a rice cooker showing a state where an earthenware pot is set in an inner case, FIG. 2 is a front view of an operation panel, FIG. 3 is a system block diagram of a control circuit portion of the rice cooker, 4 shows a time chart of the rice cooking process. The present invention is particularly suitable for rice cooking such as rice crackers with a lot of moisture, but can also be applied to a normal rice cooking process such as rice. In the following, description will be given taking rice porridge as an example.

  The rice cooker includes a rice cooker body 1 and a lid body 2 that opens and closes an upper opening of the rice cooker body 1, and the lid body 2 is supported by the rice cooker body 1 through a hinge unit 3 so as to be freely opened and closed. The rice cooker body 1 has an outer case 5 made of synthetic resin, and inside this outer case 5, a clay pot 6, which is an inner pot made of ceramics, is detachably set, and on the outside of the clay pot 6. Is provided with an inner case 7 which is a protective frame along the shape of the earthenware pot 6. The inner case 7 is made of a heat-resistant synthetic resin such as polyethylene terephthalate, for example, and a sensor insertion hole 7a is formed at the center of the bottom portion for allowing the center sensor 9 made of a thermistor to face.

  The upper end of the inner case 7 is integrally coupled to the upper end of the outer case 5 via the shoulder member 8, and a space portion 10 is formed inside the outer case 5, the inner case 7, and the shoulder member 8. Outside the inner case 7, a bottom induction coil 11 and a side induction coil 12 for induction heating the earthenware pan 6 are provided. The bottom induction coil 11 and the side induction coil 12 are provided concentrically and in series at the positions of the bottom of the inner case 7 and the curved portion extending from the bottom to the peripheral side with the center of the bottom of the inner case 7 as the center. It has been.

  A synthetic resin coil support 13 is provided outside the bottom induction coil 11 and the side induction coil 12, and the coil support 13 is attached to the inner case 7 with screws or the like. 11 and the side induction coil 12 are positioned and fixed at predetermined positions shown in the figure, and a ferrite core 15 for confining a magnetic field is provided outside the coil support base 13.

  A side heater 14 is provided on the outer peripheral side of the upper part of the inner case 7. This side heater 14 includes a side upper heater 14a, a side middle heater 14b, and a side lower heater 14c, each of which is a normal nichrome wire wound around the outer peripheral side of the upper portion of the inner case 7 in parallel from top to bottom. Although each is controlled separately, simultaneous control may be used. In this example, as shown in FIG. 4, each process is controlled with the same output. In this way, the side heaters can be heated almost uniformly over a wide range by arranging the side heaters in a plurality of rows in the vertical direction.

  The earthenware pan 6 is made of ceramics such as fired ceramics or glass, and a ring-shaped leg portion 6 a that contacts the bottom of the inner case 7 is formed on the bottom of the earthenware pot 6. The legs 6a are not limited to the ring shape, and may be formed locally or radially.

  The leg 6 a is provided between the bottom induction coil 11 on the bottom side of the inner case 7 and the side induction coil 12 on the bending side, and a certain gap S 1 is formed between the inner case 7 and the leg 6 a. It is formed at a predetermined height. Further, the earthenware pan 6 is provided with a bottom heating element 11a and a side heating element 12a made of a metal film at locations facing the bottom induction coil 11 and the side induction coil 12, respectively.

  The bottom heating element 11a and the side heating element 12a are formed, for example, by applying and baking a silver paste or the like. Since the leg 6a of the earthenware pan 6 has an uneven surface, it is difficult to form a heating element. However, the leg 6a is formed on either side of the bottom induction coil 11 or the side induction coil 12. Because it is out of position, there is no effect on rice cooking performance. The heating element may have a structure in which a metal such as a copper foil or a stainless steel net is embedded in advance in the earthenware pot 6 in advance.

  When the rice cooking switch is turned on, the bottom heating element 11a and the side heating element 12a are heated by Joule heat caused by eddy currents induced by the bottom induction coil 11 and the side induction coil 12, and the clay pot is heated by the heating of both heating elements. 6 is heated.

  Furthermore, the dome-shaped central portion 6b with which the center sensor 9 at the bottom of the earthenware pan 6 abuts is formed to be slightly thinner to the extent that the strength is not impaired compared to the other portions. Thus, by making the central portion 6b of the earthenware pan 6 thin, heat from the bottom heating element 11a and the side heating element 12a is easily conducted to the thin central portion 6b. The power supplied to the bottom induction coil 11 and the side induction coil 12 can be appropriately controlled.

  Reference numeral 18 denotes an operation panel constituting an operation unit. As shown in FIG. 2, the operation panel 18 has various switches 16 such as a rice cooking switch 16a, a heat retention switch 16b, various menus such as white rice, quick cooking, and rice porridge. A menu switch 16c for setting time, a timer switch 16d for setting time, a cancel switch 16e for canceling the setting, and a liquid crystal display unit 17 are provided.

  Reference numeral 19 is a microcomputer board on which a microcomputer is mounted, 20 is a power board on which a power supply circuit having an inverter and the like for controlling energization to the bottom induction coil 11 and the side induction coil 12 is mounted, and 21 is each of the above-mentioned A substrate cooling fan for cooling the substrates 19 and 20. In addition, 26 is a steam discharge port and 27 is a handle.

  An inner cover 24 made of aluminum is attached to the inner surface of the lid 2 so as to close the upper opening of the earthenware pot 6 when closed, and a heat radiating plate 22 is provided above the inner cover 24. A lid sensor 23 and a lid heater 25 are attached to the upper surface of the heat radiating plate 22. The lid sensor 23 is made of a thermistor and indirectly detects the temperature of the porridge in the clay pot 6. The lid heater 25 is a sheathed heater made of ordinary nichrome wire, and is arranged to meander around the upper surface of the heat radiating plate 22 so as to uniformly heat almost the entire surface of the heat radiating plate 22.

  Next, FIG. 3 shows an outline of an example of a control circuit unit such as induction coils 11 and 12 and side heaters 14 and lid heaters 25 centering on the microcomputer control device 100 for cooking rice and keeping warm. In the figure, reference numeral 40 is a microcomputer control unit (CPU) for rice cooking / warming control, and the microcomputer control unit 40 is centered on a microcomputer, for example, a temperature detection circuit unit, an induction coil drive control circuit unit, an oscillation circuit unit, A reset circuit unit, a drive control circuit unit such as a side heater and a lid heater, a power supply circuit unit, a liquid crystal display unit, and an operation switch are provided.

  The temperature detection circuit 48 provided corresponding to the center sensor 9 that is in contact with the bottom wall portion of the earthenware pan 6 or the lid sensor 23 that is attached to the heat sink 22 has a temperature at the center sensor 9 or the lid sensor 23. A detection signal is input. The induction coil drive control circuit unit is formed by, for example, a pulse width modulation circuit 46, a synchronous trigger circuit 53, an IGBT drive circuit 45, an IGBT 50, and a resonance capacitor 51.

  The microcomputer control unit 40 selects the output value of the bottom induction coil 11 and the side induction coil 12 corresponding to the rice cooking process and the ON duty ratio (for example, n seconds / 16 seconds) at the same output value, and the pulse width modulation. By controlling the circuit 46 and the like, appropriate heating control such as uniform water absorption suitable for the clay pot 6 and cooking of rice without heating unevenness is performed.

  Reference numeral D denotes a flywheel diode of the IGBT 45, reference numeral 55 denotes a rectifier circuit including a diode bridge for driving the induction coil inserted between the home AC power source 57, and reference numeral 52 denotes a smoothing circuit thereof.

  Reference numeral 14 denotes the above-described side heater, 25 denotes a lid heater, the side heater 14 is driven by the side heater driving circuit 56, and the lid heater 25 is driven ON and OFF by the lid heater driving circuit 54 at a desired duty ratio, respectively. It has become. Further, reference numeral 17 denotes a display unit such as a liquid crystal or LED, 43 denotes a notification unit such as a buzzer, 16 denotes various operation switches such as a rice cooking switch 16a, a heat retention switch 16b, and a timer switch 16d, and 47 denotes an oscillation for forming a clock reference control signal. A circuit 44 is a reset circuit.

  Next, the rice cooking control of the rice cracker performed using the above-mentioned microcomputer control unit 40 is demonstrated with reference to the time chart of FIG. Although the figure shows only the rice cooking process, if it has a heat retaining process, the heat retaining process is subsequently executed.

  In the rice cooking process, by increasing the output of the induction coils 11 and 12 to a predetermined value, the water absorption process for causing the rice to absorb water is the main IH, that is, the bottom induction coil 11 for a predetermined time (10 minutes). And the side induction coil 12 is executed with an output of 70% and an ON duty ratio of 8/16 (the side heater 14 and the lid heater 25 are OFF). When sufficient water absorption is performed on the rice, a heating process is performed in which the output is rapidly increased and the rice is cooked at once.

  The temperature raising step is composed of two stages of a temperature raising step 1 and a temperature raising step 2. The temperature raising step 1 is a side heater with the main IH output 70%, the ON duty ratio 16/16, the lid heater 25 is OFF, until the lid sensor 23 detects 53 ° C. which is the first predetermined temperature T1. Each of the upper side heater 14a, the inner side heater 14b, and the lower side heater 14c is executed at a high power with an ON duty ratio of 10/16. For safety, a time of 40 minutes can be set. By setting this time, for example, when the lid sensor 23 does not detect 53 ° C. within 40 minutes due to a failure of the lid sensor 23 or the like, the process proceeds to the next two temperature raising steps. If necessary, the total number of cooked rice in the inner pot is determined based on the temperature rise time in one step of temperature increase, and the subsequent cooking process time is determined according to the total number of cooked rice. It may be.

  When the process proceeds to the temperature rise 2 step, the main IH is output 60%, the ON duty ratio is 12/16, the lid heater 25 is turned off, and the side heater is turned on until the lid sensor 23 detects the second predetermined temperature T2 of 65 ° C. Each of the upper side heater 14a, the inner side heater 14b, and the lower side heater 14c is executed with a medium electric power smaller than one step of temperature increase with an ON duty ratio of 10/16. For safety, a time of 10 minutes can be set. By setting this time, for example, when the lid sensor 23 does not detect 65 ° C. within 10 minutes due to a failure of the lid sensor 23, the process proceeds to the next cooking step.

  When the temperature raising process is completed, the cooking process for maintaining the boiling temperature is performed for a predetermined time (33 minutes), the main IH is output 60%, the ON duty ratio is 3/16, and the lid heater 25 is turned ON duty ratio 6 / 16, each of the upper side heater 14 a, the side side heater 14 b, and the lower side heater 14 c, which are side heaters, is executed with a small electric power smaller than two steps of heating with an ON duty ratio of 8/16, and is detected by the lid sensor 23. Is controlled to be maintained at 100 ° C., which is the boiling temperature Tf. The predetermined time (33 minutes) may be increased or decreased according to the total number.

  After the cooking process, the spotting process is executed to finish the rice cooking process. In the unevenness process, the lid heater 25 is ON duty ratio 6/16 for a predetermined time (7 minutes), and each of the side heater 14a, the side heater 14b, and the side heater 14c as side heaters is ON duty ratio 8/16. Of power.

  Next, the control of rice cracker cooking in the clay pot 6 will be described based on the flowchart of FIG. The rice cooking process starts when rice cooking rice is selected with the menu switch 16c of the various switches 16 and the rice cooking switch 16a is pressed.

  First, in step S1, a water absorption process is executed. In the water absorption process, the main IH, that is, the bottom induction coil 11 and the side induction coil 12 have an output of 70%, an ON duty ratio of 8/16, the lid heater 25 and the side heater 14a as the side heater, the side heater 14b, Each of the lower side heaters 14c is executed with OFF, and then it is determined whether or not 10 minutes have passed in step S2.

  If 10 minutes have not elapsed in step S2, the determination is repeated. If an affirmative determination is made in step S2, the water absorption process is terminated, and the process proceeds to the temperature increase 1 process in step S3. In the temperature raising step 1, the main IH is output 70%, the ON duty ratio is 16/16, the lid heater 25 is OFF, and the side heater 14a, the side heater 14b, and the side heater 14c are turned on. The process is executed with high power with a duty ratio of 10/16, and then it is determined in step S4 whether the lid sensor 23 has detected 53 ° C., which is the first predetermined temperature T1.

  If 53 ° C. is not detected in step S4, the determination is repeated. If an affirmative determination is made in step S4, the temperature raising step 1 is terminated and the process proceeds to step S5. In the temperature rising step 2, the main IH is output 60%, the ON duty ratio is 12/16, the lid heater 25 is OFF, and the side heater 14a, the side heater 14b, and the side heater 14c are ON. The process is executed with a medium power smaller than the temperature rising 1 step with a duty ratio of 10/16, and then it is determined whether or not the lid sensor 23 has detected the second predetermined temperature T2 of 65 ° C. in step S6.

  If 65 degreeC is not detected by step S6, the determination will be repeated, and if affirmation determination is made by step S6, 2 steps | paragraphs of temperature rising will be complete | finished and it will progress to the cooking process of step S7. In the cooking process, the main IH has an output of 60%, an ON duty ratio of 3/16, the lid heater 25 has an ON duty ratio of 6/16, and the side heater 14a, the side heater 14b and the side heater 14c are side heaters. Each of the above is executed with a small electric power smaller than 2 steps of temperature increase with an ON duty ratio of 8/16, and the heating is controlled so that the temperature detected by the lid sensor 23 is maintained at the boiling temperature Tf of 100 ° C. Thereafter, it is determined whether or not 33 minutes have passed in step S8.

  If 33 minutes have not elapsed in step S8, the determination is repeated. If an affirmative determination is made in step S8, the cooking process is terminated and the process proceeds to the unevenness process in step S9. In the unevenness process, the lid heater 25 is executed at an ON duty ratio of 6/16, and each of the side heater 14a, the side heater 14b, and the side heater 14c, which are side heaters, is executed at an ON duty ratio of 8/16. Thereafter, it is determined whether or not 7 minutes have passed in step S10.

  If 7 minutes have not elapsed in step S10, the determination is repeated. If an affirmative determination is made in step S10, the unevenness process is terminated and the rice cooking process is terminated. And if the heat retention process is set after that, the process will be performed.

  The above control uses the detected temperature of the lid sensor 23 to gradually lower the heating output from the temperature raising process to the cooking process to suppress the temperature rise of the clay pot 6. The detection temperature curve of the center sensor 9 in the earthenware pot cooking is higher than the detection temperature curve of the lid sensor 23 as shown in FIG. 4 due to the heat storage property of the earthenware pot, and when the detection temperature of the center sensor 9 is used. Even if the heating output is lowered, it is difficult to prevent spillage such as rice porridge. On the other hand, the lid sensor 23 can detect a temperature relatively close to the temperature of the contents although it is indirect, and thus can more reliably prevent the boiling of the porridge in the clay pot. In the control in this example, the detected temperature in the temperature raising process is in two stages, T1 and T2, but the heating output may be gradually decreased in more stages.

  By the way, a rice cooking process heats rapidly until it reaches the boiling temperature Tf at a temperature rising process, and then performs the cooking process while maintaining the boiling temperature Tf. The boiling temperature maintenance heating at the cooking process is important for rice cooking. It has become an element. Even in the example of FIG. 5, heating that maintains the boiling temperature during the cooking process is possible, but since the contents such as porridge are indirectly detected by the lid sensor 23, the accuracy is somewhat problematic. .

  The thing of FIG. 6 eliminates such a bad effect, and compares the temperature detected by the lid sensor 23 with the temperature detected by the center sensor 9 during the cooking process, and adjusts the output so that there is no difference between the two temperatures. In the cooking process, the heating control that reflects the detected temperature of the contents is performed. The example of FIG. 6 will be described. Since the steps up to step S7 are the same as those in FIG. 5, the description thereof is omitted.

  In the cooking process, the main IH has an output of 60%, an ON duty ratio of 3/16, the lid heater 25 has an ON duty ratio of 6/16, and the side heater 14a, the side heater 14b and the side heater 14c are side heaters. Each of these is executed with a small electric power smaller than the temperature rising two steps with an ON duty ratio of 8/16. Thereafter, in step S8, the detected temperature Ta at the lid sensor 23 and the detected temperature Tb at the center sensor 9 are compared.

  If it is determined in step S8 that the detected temperature Tb at the center sensor 9 is higher than the detected temperature Ta at the lid sensor 23, the process proceeds to step S9, and the lid heater 25, the side heater 14a that is a side heater, and the side heater 14b. The output of the main IH is lowered with each of the lower side heaters 14c kept ON, and the process returns to step S8, where the detected temperature Ta at the lid sensor 23 and the detected temperature Tb at the center sensor 9 are compared again. When it is determined again in step S8 that the detected temperature Tb at the center sensor 9 is still higher than the detected temperature Ta at the lid sensor 23, the process proceeds to step S9, where the lid heater 25 and the side heater 14a as a side heater are provided. The process is repeated so that the output of the main IH is further lowered and the process returns to step S8, with the outputs of the side heater 14b and the lower side heater 14c unchanged. That is, the output of the main IH is gradually lowered to reduce the difference between the detected temperature Ta at the lid sensor 23 and the detected temperature Tb at the center sensor 9 so that they become equal.

  If a negative determination is made in step S8, the process proceeds to step S10. The process proceeds to step S10 when the detected temperature Ta at the lid sensor 23 and the detected temperature Tb at the center sensor 9 are substantially equal. However, since the temperature may not be the boiling temperature Tf (100 ° C.), this point is determined in step S10. Since the detection temperature Ta at the lid sensor 23 may not be higher than the detection temperature Tb at the center sensor 9, the detection temperature Ta at the lid sensor 23 is higher than the detection temperature Tb at the center sensor 9. If it is determined, a function for determining that the sensor is in an abnormal state may be added.

  In step S10, it is determined whether the detected temperature Ta at the lid sensor 23 and the detected temperature Tb at the center sensor 9 are equal to the boiling temperature Tf. If it is determined that they are not equal, the main IH is determined according to the temperature difference between the two. The heating control is repeated so as to eliminate the temperature difference between the two.

  If it is determined in step S10 that the detection temperature Ta detected by the lid sensor 23 and the detection temperature Tb detected by the center sensor 9 are equal to the boiling temperature Tf, the process proceeds to step S11, where the main IH and the lid heater 25 are turned off. It progresses to the unevenness process of S12. In addition, by performing the heating control with Ta = Tb = Tf, the cooking temperature of the entire clay pot can be made substantially uniform, and an almost ideal cooking process can be realized.

  In the unevenness process, the lid heater 25 is executed at an ON duty ratio of 6/16, and each of the side heater 14a, the side heater 14b, and the side heater 14c, which are side heaters, is executed at an ON duty ratio of 8/16. Thereafter, it is determined whether or not 7 minutes have passed in step S13. If 7 minutes have not elapsed in step S13, the determination is repeated. If an affirmative determination is made in step S13, the unevenness process is terminated and the rice cooking process is terminated. And if the heat retention process is set after that, the process will be performed.

Vertical section of the rice cooker showing the state that the clay pot is set in the inner case Front view of the operation panel System block diagram of control circuit part of rice cooker Time chart of rice cooking process Flow chart of rice porridge Flow chart of rice porridge Flowchart diagram of conventional rice porridge

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Rice cooker main body 2 ... Cover body 3 ... Hinge unit 5 ... Outer case 6 ... Earthenware pan 6a ... Leg part 6b ... Center part 7 ... Inner case 7a ... Sensor insertion hole 8 ... Shoulder member 9 ... Center sensor 10 ... Space part 11 ... Bottom induction coil 11a ... Bottom heating element 12 ... Side induction coil 12a ... Side heating element 13 ... Coil support 14 ... Side heater 15 ... Ferrite core 16 ... Operation switch 16a ... Rice cooker switch 16b ... Insulation switch 16c ... Menu switch 16d ... Timer switch 16e ... Cancel switch 17 ... Display 18 ... Operation panel 19 ... Microcomputer board 20 ... Power supply board 21 ... Cooling fan 22 ... Heat sink 23 ... Cover sensor 24 ... Inner cover 25 ... Cover heater 26 ... Steam outlet 27 ... handle 40 ... microcomputer control unit 43 ... notification unit 44 ... reset circuit 45 ... IGBT drive Road 46 ... pulse width modulation circuit 47 ... oscillation circuit 48 ... temperature detection circuit 50 ... IGBT
DESCRIPTION OF SYMBOLS 51 ... Resonance capacitor 52 ... Smooth trigger circuit 53 ... Synchronous trigger circuit 54 ... Cover heater drive circuit 55 ... Rectifier circuit 56 ... Side heater drive circuit 57 ... Household AC power supply 100 ... Microcomputer control apparatus

Claims (2)

The heating rate during cooking is relatively slow compared to a metal inner pot and a good heat storage clay pot, an inner case for storing the clay pot, heating means for heating the clay pot, and a lid A lid sensor for detecting the temperature of the lid body, a center sensor for detecting the temperature of the earthenware pot provided in the rice cooker body, a heating control means for controlling the heating state of the heating means, and an operation part having a display part. In a rice cooker having at least a heating step and a cooking step in the rice cooking process,
The control of the heating control means includes a control for detecting a predetermined temperature below the boiling temperature based on a signal from only the lid sensor and gradually decreasing the heating output to gradually reduce the power consumption. rice cooker. An inner pot made of ceramic, an inner case for storing the inner pot, a heating means for heating the inner pot, a lid sensor for detecting the temperature of the lid provided on the lid, and a rice cooker body A rice cooker comprising a center sensor for detecting the temperature of the inner pot, a heating control means for controlling the heating state of the heating means, and an operation part having a display part, and having at least a heating step and a cooking step in the rice cooking step In
In the control of the heating control means, the power consumption is gradually reduced based on the signal of the lid sensor,
In the cooking step, a control for adjusting the power consumption so that the detection temperature of the lid sensor and the detection temperature of the center sensor are equal by comparing the detection temperatures of the lid sensor and the center sensor. A rice cooker characterized by having.

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