JP2006014774A - Rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rice cooker capable of correcting secular change and performing cooking under an optimum condition. <P>SOLUTION: The rice cooker 1 is provided with an inner pot 4 and a heating means 6 for heating the inner pot 4 and corrects the power of the heating means 6 by a power correction instruction value stored in a storage device 9. The number of times of cooking is counted, the power of the heating means 6 is measured for every prescribed number of times of cooking and the power correction instruction value is changed such that the power becomes equal to a prescribed power reference value. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rice cooker.

  In a rice cooker that cooks the contents of the inner pot by heating the inner pot with heating means, a preferable rice cooking result is obtained by cooking each step of rice cooking at an appropriate temperature for an appropriate time. For this reason, in the cooking process, various parameters such as an energization rate are set and controlled in the cooking process in order to realize a heating amount that allows cooking to be completed in an appropriate time while maintaining a set temperature.

  However, the conventional rice cooker has a problem in that the output characteristics of the heating means and the output characteristics of the temperature sensor vary depending on manufacturing variations and aging, and it is not always possible to perform optimum cooking as designed. In particular, in an IH rice cooker, the output may change if the distance between the inner pot and the heating coil (heating means) changes even slightly.

Patent Document 1 discloses a cooking device that measures the power of a heating coil, stores an error from a predetermined power value in an E ² PROM (storage device), and controls the drive device by a microcomputer so as to eliminate the error. Are listed.
Japanese Patent Laid-Open No. 10-208857

  However, the cooking device of Patent Document 1 has a problem that it is troublesome because it is necessary to measure power in a special mode and store data for correction. Further, there is no means for correcting variations in manufacturing and aging of temperature sensors and the like.

  Then, in view of the said problem, this invention makes it a subject to provide the rice cooker which correct | amends secular change and can cook on optimal conditions.

  In order to solve the above problems, the rice cooker of the present invention has an inner pot and a heating means for heating the inner pot, and corrects the power of the heating means with the power correction instruction value stored in the storage device. A rice cooker that counts the number of times of cooking, measures the power of the heating means every predetermined number of times of cooking, and changes the power correction instruction value so that the power becomes equal to a predetermined power reference value Shall.

  According to this configuration, the power of the heating means is automatically corrected every predetermined number of cooking times to obtain an appropriate output. For this reason, even if it does not perform a special operation | work, the performance of a rice cooker can be maintained for a long period of time.

  Moreover, the rice cooker of this invention WHEREIN: The measurement of the said electric power may be measured when the electric power of the said heating means is the maximum, and may be performed at the time of the heating of a boiling process or a preheating process.

  According to this configuration, since the maximum power of the heating unit is measured and corrected, the correction can be made with high accuracy. In addition, if correction is performed in the boiling process that maintains the maximum power for a relatively long time until boiling after preheating, the correction error can be reduced, and the power can be corrected when heating to a preheating temperature at which the maximum power is maintained stably. Even so, the correction error can be reduced.

  Moreover, the rice cooker of this invention WHEREIN: You may memorize | store the said electric power reference value in a memory | storage device before shipment.

  According to this configuration, even if the optimum output of the heating means varies depending on individual differences during manufacture, the optimum reference power is stored in each rice cooker, so that variation between products is reduced.

  Moreover, the rice cooker of this invention is a rice cooker which has an inner pot, the sensor which detects the state at the time of rice cooking, and the heating means which heats an inner pot based on the output of the said sensor, Comprising: The reference value of the output of the sensor is stored in a storage device, and when the inner pot is heated by the heating means by selecting a mode for calibrating the output of the sensor, the output of the sensor under the predetermined condition is measured. A calibration constant for calibrating the sensor may be determined according to a difference from the reference value.

  According to this configuration, even if the output characteristics of the sensor change over time, the output of the sensor can be calibrated as necessary, so that the performance of the rice cooker can be maintained for a long time.

  Further, in the rice cooker of the present invention, the sensor is a temperature sensor that detects a temperature at the time of rice cooking, and in the calibration mode, a predetermined amount of water put in the inner pot is boiled, and at the time of the boiling The temperature sensor may be calibrated by measuring the output of the temperature sensor.

  According to this configuration, the boiling temperature of water is always 100 ° C., and the temperature of the temperature sensor when the thermometer is calibrated becomes constant by making the amount constant. For this reason, the error of a temperature sensor can be measured correctly and the temperature sensor of a rice cooker can be calibrated correctly.

  As mentioned above, the rice cooker of this invention can correct | amend a secular change, and can cook it on optimal conditions.

  Embodiments of the present invention will be described below with reference to the drawings.

  Drawing 1 is a sectional view of rice cooker 1 of an embodiment of the present invention. The rice cooker 1 includes a main body 2 and a lid 3, and an inner pot 4 is accommodated in the main body 2. An inner lid 5 is attached to the lid 3 so as to seal the upper opening of the inner pot 4. The rice cooker 1 cooks by heating the inner pot 4 with a heating coil 6 which is a heating means provided in the main body 3. The main body 3 is provided with a temperature sensor 7 that contacts the outer surface of the inner pot 4 and detects the temperature of the inner pot 4. The heating coil 6 is driven by a drive circuit 8 whose energization rate can be changed. The drive circuit 8 drives the heating coil 6 with a maximum value (energization rate 100) based on a value stored in a memory 9 which is a nonvolatile storage device. %)) Is set.

  The memory 9 includes a power reference value that is the maximum power at the time of shipment of the heating coil 6, a sensor reference value that is an output of the temperature sensor 7 under a predetermined condition at the time of shipment, and a power correction instruction value that corrects the maximum power. There is an area for storing a sensor calibration constant for correcting the output of the temperature sensor 7 and a counter for counting the number of times of cooking. In the rice cooker 1, various parameters such as the energization rate and heating time of the heating coil 6 are optimized so that an optimum rice cooking result can be obtained in the aging inspection before factory shipment. Each value is measured and stored in the memory 9, the power correction instruction value and the sensor calibration constant are stored as values indicating no correction, and 0 is stored in the counter.

  In the rice cooker 1, the output of the drive circuit 8 is automatically changed and corrected so that the maximum output of the heating coil 6 becomes the same as the power at the time of factory shipment every predetermined number of operations.

  In FIG. 2, the correction | amendment procedure of the maximum value of the electric power which drives the heating coil 6 in the rice cooker 1 is shown. Every time cooking is started, the rice cooker 1 adds 1 to the counter in step S1, and confirms that the counter has reached 1000 in step S2, and then drives the heating coil 6 with maximum power after preheating in step S3. Then, the electric power of the heating coil 6 is measured in a boiling process in which the water in the inner pot 4 is boiled. In step S4, a correction instruction value capable of appropriate correction is determined from the difference between the measured value and the power reference value. In step S5, the correction instruction value is stored in the memory 9, and in step S6, the counter is reset to zero.

(Calculation example)
A specific calculation example of power correction according to the above correction procedure will be described.

  As the power reference value, for example, a value obtained by AD conversion with 3W as 1 is stored, the power correction instruction value is stored as a value of 1 byte (0 to F in hexadecimal), and −70 W when the power correction instruction value is 0 When the power correction instruction value is 7, ± 0 W is obtained, and when the power correction instruction value is F, +80 W is obtained.

  For example, if the measured value of the maximum power of the heating coil 6 during the aging test is 514 W, AB is stored in the memory 9 as a power reference value in hexadecimal notation.

  In step S3, the average voltage and average current applied to the heating coil 6 are measured to calculate a power value, which is similarly expressed in hexadecimal. For example, if the power value at this time is 481 W, A0 is obtained.

  In step S4, the difference between the power reference value and the measured power value of the coil 6 is obtained. In this case, when A0 is subtracted from AB, 0B is obtained. Therefore, a power correction instruction value capable of performing correction closest to this value is obtained. When 0B is converted back to electric power, it is 33 W, and A for correcting +30 W is obtained as the electric power correction instruction value.

  By rewriting the power correction instruction value of the memory 9 to A in step S5, the output of the coil 6 when the energization rate is 100% is about 511 W, and is almost the same as the output value of 514 W, which is a measurement value at the time of aging inspection. Become.

  Moreover, in the rice cooker 1, the temperature sensor 7 can be calibrated by putting 1000 cc of water into the inner pot 4 and selecting and operating the calibration mode.

  FIG. 3 shows an operation procedure when the mode for calibrating the temperature sensor 7 is selected. When the calibration mode is selected and the heating operation is started, in step S11, the drive circuit 8 drives the heating coil 6 at an energization rate (maximum output) of 100% to heat the inner pot 4. If the output of the temperature sensor 7 is stabilized in step S12, that is, if the water boils and becomes constant at 100 ° C. and the output of the temperature sensor 7 that rises with the rise of the water temperature stops increasing, in step S13, A sensor calibration constant to be added to the output is determined so that the output becomes the same value as the sensor reference value stored in the memory 9. In step S14, the sensor calibration constant is stored in the memory 9, and in step S15, the output of the heating coil 6 is stopped and the calibration procedure of the temperature sensor 7 is completed.

  As described above, the advantages of the rice cooker 1 that can automatically correct the electric power of the heating coil 6 or calibrate the temperature sensor 7 will be described.

  The rice cooker 1 of this embodiment automatically changes the electric power of the heating coil 6 that influences the cooking time of the boiling process that greatly affects the cooking of rice every time 1000 times of rice cooking so that it is close to the preferred power value at the time of shipment. Therefore, the performance at the time of shipment can be maintained.

  In the rice cooker 1, the electric power of the heating coil 6 is measured in the boiling process to determine the correction instruction value. However, the measurement of the electric power of the heating coil 6 is not limited to the boiling process, and the electric power of the heating coil 6 is maximum. When the energization rate is 100%, the correction error is small. For example, it may be performed while the heating coil 6 is heated to the preheating temperature in the preheating step.

  Moreover, when the preheating temperature is different from the design temperature, the water absorption rate of rice changes, which affects the cooking of rice. However, in the rice cooker 1, the user can easily calibrate the temperature sensor 7 so that the optimum rice cooking result can be obtained. Can be.

Sectional drawing of the rice cooker of embodiment of this invention. The flowchart which shows the correction | amendment procedure of the output of the heating coil of the rice cooker of FIG. The flowchart which shows the calibration procedure of the temperature sensor of the rice cooker of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rice cooker 2 Main body 3 Lid 4 Inner pan 5 Inner lid 6 Heating coil (heating means)
7 Temperature Sensor 8 Drive Circuit 9 Memory (Storage Device)

Claims (7)

An inner pot, and heating means for heating the inner pot,
A rice cooker that corrects the power of the heating means with the power correction instruction value stored in the storage device,
Counting the number of times of cooking, measuring the power of the heating means every predetermined number of times of cooking, and changing the power correction instruction value so that the power becomes equal to a predetermined power reference value .   The rice cooker according to claim 1, wherein the measurement of the electric power is performed when the electric power of the heating means is maximum.   The rice cooker according to claim 2, wherein the power is measured in a boiling step.   The rice cooker according to claim 2, wherein the measurement of the electric power is performed at the time of heating in the preheating step.   The rice cooker according to any one of claims 1 to 4, wherein the power reference value is stored in a storage device before shipping. A rice cooker having an inner pot, a sensor for detecting the state at the time of rice cooking, and a heating means for heating the inner pot based on the output of the sensor,
Storing a reference value of the output of the sensor in a predetermined condition in a storage device;
When the mode for calibrating the output of the sensor is selected and the inner pan is heated by the heating means, the output of the sensor under the predetermined condition is measured, and the sensor is calibrated according to the difference from the reference value. A rice cooker characterized by determining a calibration constant to be performed. The sensor is a temperature sensor that detects the temperature during cooking,
In the calibration mode, boil a predetermined amount of water in the inner pot,
The rice cooker according to claim 6, wherein the temperature sensor is calibrated by measuring an output of the temperature sensor during the boiling.

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