JP2005046491A - Rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the finish of rice cooking by improving the variation of temperature change without regard to various kinds of factors. <P>SOLUTION: In order to heat pot for boil-heating etc, a rice cooking control means 95 first sets a controlled temperature changing according to time. Thereafter, whenever fetching a detected temperature p2 from a lid temperature sensor 57, the rice cooking control means 95 adjusts the heating amount of a heating coil 16 in proportion to the difference between the controlled temperature and the detected temperature p2, in proportion to a quantity obtained by adding the difference between the controlled temperature and the detected temperature p2 until a fixed time before, or in proportion to the difference of the two amounts by respectively calculating the amounts of differences between the controlled temperature and the detected temperature p2 of this time and a fixed time before. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rice cooker that obtains a desired cooked rice to be cooked under the control of a control means.

For example, as disclosed in Patent Document 1, a conventional rice cooker performs a boiling process for promoting water absorption of rice in a pan, boiling heating for boiling water in a pan and starting rice gelatinization, and boiling. A microcomputer that is the control means for each process of boiling continuous heating, which continues this boiling state after detection and gelatinizes the rice, and keeps the cooked rice at a high temperature to promote gelatinization and finishes rice. (Hereinafter referred to as a microcomputer) are executed sequentially. In general, the time required from the water temperature of 20 ° C. to the boiling point of 100 ° C. is ideally about 10 minutes.
Japanese Patent Laid-Open No. 11-187975

  As shown in FIG. 6, conventional rice cooking is generally performed with a predetermined heating pattern until the inside of the pan reaches a constant temperature or else a predetermined time elapses. For this reason, even if heating is performed with the same heating pattern, the temperature change in the pan differs depending on the amount of rice cooked, and there is a problem that the desired cooking (hardness, temperature unevenness, etc.) cannot be obtained. In addition, in order to make the temperature change constant regardless of the amount of rice cooked, the rice cooking capacity in the pan is obtained based on the temperature change when constant heating is applied, such as in the process of running before substantial rice cooking, Although the method of changing the amount of heating according to this rice cooking capacity is known, because there is a limit to the accuracy of determining the rice cooking capacity, for example, it can only be judged roughly in three categories of large capacity, medium capacity, and small capacity. It was. For example, in a rice cooker that cooks 1 to 5.5 cups (1 cup = 180 ml), 1 to 2.5 cups are small, 2.5 to 4.0 cups are medium, 4.0 to 5.5 cups are large, and the rice cooking capacity is determined at the boundary. For example, when 2.5 cups is determined to be a small amount and when it is determined to be a medium amount, the amount of heating given to the pan differs greatly, and as a result, the temperature change in the pan also varies greatly. Moreover, even if it determines with the same small quantity, when cooking 1 cup of rice and 2 cups of rice, the temperature change in a pan also changes a lot. That is, as shown in FIG. 6, when 2 cups of rice were put into a pan and cooked, the rise in the rice temperature was slower than during ideal heating, and conversely, 1 cup of rice was put into a pan and cooked. In this case, the rice temperature rises more rapidly than during ideal heating. Such variation in temperature change is a major factor that makes it impossible to cook as intended.

  Furthermore, depending on various factors such as the ambient temperature, the ratio of water and rice, the power supply voltage, and the detection accuracy of the temperature detection means, the determination of rice cooking capacity may be falsely detected. It was a factor that I couldn't get any more.

  Then, in view of the said problem, this invention makes it the objective to provide the rice cooker which can improve the variation in a temperature change, and can improve cooking without being influenced by various factors.

  In the rice cooker according to claim 1 of the present invention, for example, when heating the pot such as boiling heating, the control means first sets a control temperature that varies with time. After that, every time the control means takes in the detected temperature from the temperature detecting means, it is proportional to the difference between the control temperature and the detected temperature, or the difference between the control temperature and the detected temperature of the temperature detecting means up to a certain time before. The amount of difference between the control temperature and the temperature detected by the temperature detecting means a certain time before this time is calculated in proportion to the integrated amount, and the heating means is proportional to the difference between the two amounts. Adjust. In this way, the control of the heating means that brings the inside of the pan quickly to the target control temperature is performed every time the temperature detected by the temperature detecting means is taken in, so that the pan can be heated as ideal.

  In the rice cooker in Claim 2 of this invention, the control means which controls operation | movement of each part of a rice cooker is comprised like a hardware by the some control part. If it does in this way, each function of a control means can be distributed to a plurality of control parts, without concentrating on one control part.

  In the rice cooker according to claim 3 of the present invention, for example, calculation of the heating amount of the heating means, etc. that requires a lot of processing is performed by the second control unit having a high-speed calculation function, and other simple processing. Can be performed by the first control unit having a low consumption function. Thereby, rice cooking as a target can be performed by the high-speed arithmetic processing by the 2nd control part. Further, if only the first control unit is backed up by a battery during a power failure, the life of the battery can be extended.

  In the rice cooker according to claim 4 of the present invention, the second control unit can be reset by the first control unit, and there is no need to provide a separate reset circuit. Therefore, the part cost inside the rice cooker can be suppressed, and the reliability of the product can be improved by further simplifying the program.

  According to the rice cooker in claim 1 of the present invention, it becomes possible to heat the inside of the pan as ideal, and it is not influenced by various factors, and it is possible to improve the variation in temperature change and improve the cooking. it can.

  According to the rice cooker in claim 2 of the present invention, it is possible to distribute the functions of the control means to a plurality of control units and perform optimal control according to the processing capability of each function.

  According to the rice cooker in claim 3 of the present invention, the rice cooker can be performed as intended by high-speed arithmetic processing using the second control unit, and only the first control unit is backed up by the battery at the time of power failure. Thus, the battery life can be extended.

  According to the rice cooker in claim 4 of the present invention, it is possible to reduce the component cost and improve the reliability of the product by having the first control unit also function as the reset circuit.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  First, the basic configuration of the rice cooker will be described with reference to FIG. 1. Reference numeral 1 denotes a rice cooker body that is an outline of the rice cooker. The rice cooker body 1 includes a substantially cylindrical outer frame 2 and an outer frame 2. The bottom plate 3 is provided so as to cover the lower surface opening. On the upper side of the rice cooker main body 1, a lid, that is, a lid body 5 is rotatably supported by a hinge shaft 4 that is a hinge located at the rear part thereof. Moreover, rice cooking is carried out by a substantially cylindrical pot accommodating portion 6 formed by hanging integrally from the upper inner peripheral portion of the outer frame 2 and an inner frame 8 provided so as to cover the lower surface opening of the pot accommodating portion 6. A bottomed cylindrical pot housing 9 is formed in the vessel body 1. In addition, the pot accommodating part 6 which makes the side part of the pot accommodating body 9 consists of synthetic resins, such as PP (polypropylene) integrated with the outer frame 2. As shown in FIG. Moreover, the inner frame 8 which makes the bottom part of the pan | casing container 9 is formed with synthetic resins, such as PET (polyethylene terephthalate).

  You may comprise the main body external appearance of a rice cooker in the outer frame which integrated the upper part and the side part, ie, the outer frame 2, and the baseplate 3 which covers the bottom part of the outer frame 2. As shown in FIG. Further, the main body appearance is configured by an upper frame that covers the upper part and a bottom side frame that integrates the side part and the bottom part, or an upper frame that covers the upper part, a side frame that covers the side part, and a bottom plate that covers the bottom part. You may comprise by. At that time, the outer frame, the bottom plate, the top frame, and the bottom side frame are all formed of a synthetic resin such as PP, but the side frame may be formed of a synthetic resin such as PP or a metal plate such as stainless steel. May be formed.

  In the pot housing 9, a bottomed cylindrical pot 11 for storing an object to be cooked such as rice or water is detachably accommodated. This pan 11 is a pan body 12 mainly made of aluminum with good thermal conductivity, and a heating element 13 composed of a magnetic metal plate such as ferritic stainless steel joined from the lower side to the bottom of the outer surface of the pan body 12. It consists of. The reason why the heating element 13 is not provided from the center to the top of the side surface of the pan 11 is to reduce the weight of the pan 11. An annular flange portion 14 is formed around the upper end of the pan 11 so as to extend to the outer periphery thereof.

  As described above, a heating element 13 made of a magnetic metal material using ferritic stainless steel is provided on the outer bottom portion of the pot 11, and this is integrally formed with the pot body 12 by molten metal forging. Further, the pot housing 9 on the outside of the pot 11 is formed in a shape substantially similar to the outer surface shape of the pot 11.

  The inner frame 8 is positioned to face the heating element 13 of the pan 11, but the bottom part of the pot 11, particularly the bottom part, is electromagnetically placed on the lower side and bottom part of the outer surface of the inner frame 8 facing the heating element 13. A heating coil 16 is provided as a heating means for induction heating. The heating coil 16 is spirally wound around and fixed to the outer surface of the inner frame 8 while facing the heating element 13 on the outer surface of the pan 11. When a high frequency current is supplied to the heating coil 16 from an inverter circuit of the heating control means 71 described later, an eddy current is generated in the heating element 13 in the magnetic field by the alternating magnetic field generated from the heating coil 16. Then, the eddy current is converted into Joule heat, so that the heating element 13 generates heat, and the cooked rice such as water and rice in the pan 11 and the pan 11 is heated. Further, a ferrite core 17 is provided so as to cover the heating coil 16 from below.

  A pan temperature sensor 21 serving as a pan bottom temperature detecting means that elastically contacts the bottom outer surface of the pan 11 and detects the outer surface temperature of the pan 11 is supported by a sensor holder 22 at the center of the bottom of the inner frame 8. Is provided. The pan temperature sensor 21 is preferably composed of a negative characteristic thermistor, and mainly controls the heating temperature at the bottom of the pan 11 by the heating coil 16.

  At the upper end of the pot housing 9, a cord heater 26 as a pot side heating means for heating the upper part of the pot 11, particularly the flange part 14, is located below the flange part 14 of the pot 11 and is circular. It is arranged in a ring. The cord heater 26 is composed of an electric heater, and is held on a heater ring 27 as a heat dissipation suppressing member mounted so as to be placed on the upper end of the pot housing 9 and covers the cord heater 26 from above. In this way, the metal plate 29 that is attached to the heater ring 27 and has both excellent heat conductivity and made of, for example, an aluminum plate and a heat radiating portion is provided. The metal plate 29 is positioned to face the gap 30 between the rice cooker body 1 and the lid 5. Then, the lower surface of the flange portion 14 of the pan 11 is placed on the upper surface of the metal plate 29, so that the pan 11 is accommodated in the pan accommodating body 9 in a suspended state. Therefore, there is almost no gap between the pan 11 and the upper end of the pan housing 9 in which the pan 11 is housed. Moreover, the flange portion 14 of the pan 11 has an outer shape that is equal to or greater than the size of the cord heater 26, so that the cord heater 26 is covered with the flange portion 14 of the pan 11 from above. . However, although not shown, for example, by bending the cord heater 26 downward at the left and right side portions of the pan container 9, the flange portion 14 and the cord heater 26 are brought into non-contact with each other. A gap is partially formed between them, and the flange portion 14 can be used as a handle portion when the pan 11 is attached and detached in this gap. The partial gap also has an action of discharging steam when cooking rice with water attached to the outer surface of the pan 11.

  The lid body 5 is fixed to a hinge shaft 4 that is a rotating shaft thereof, and is biased in a direction of opening with the hinge shaft 4 as a fulcrum by the force of a hinge spring 41 wound around the hinge shaft 4. Further, a hook 43 provided on the upper side of the front portion of the outer frame 2 is detachably engaged with a clamp 42 as a lid engaging portion provided at the front portion of the lid body 5, so that the hinge spring 41 is engaged. The lid 5 is held in a closed state against this force. A compression spring (not shown) that biases the hook 43 in a direction to engage with the clamp 42 is provided on the back side of the hook 43 that also serves as an opening / closing button.

  The lid 5 includes an outer lid 46 made of, for example, plastic that forms an upper shell of the lid 5, a heat radiating plate 47 as a lid lower surface material that forms a lower surface that is the inner surface of the lid 5, and the outer lid 46 and the heat radiating plate 47. And an outer lid cover 48 as a lid base material that forms a skeleton of the lid body 5. An inner lid 51 that directly covers the upper opening of the pan 11 is detachably mounted on the lower surface, which is the inner surface of the lid 5, with a predetermined gap formed between the lower surface and the lower surface. The heat radiating plate 47 and the inner lid 51 are both made of metal, and are made of, for example, a metal material anodized with stainless steel or aluminum. A packing base 52 is fixed to the outer peripheral portion of the inner lid 51, and a lid packing 53 is fixed by being sandwiched between the packing base 52 and the inner lid 51. The lid packing 53 is formed in an annular shape by an elastic member such as silicone rubber or fluororubber, and abuts against the upper surface of the flange portion 14 of the pan 11 to close the gap between the pan 11 and the inner lid 51. The steam generated from 11 is sealed. The contact portion of the lid packing 53 with the pan 11 faces the cord heater 26 with the flange portion 14 in between.

  A lid heater 56 as a lid heating means is provided on the upper surface of the heat radiating plate 47 inside the lid 5. The lid heater 56 may be an electric heating heater such as a cord heater or a heating coil by electromagnetic induction heating. Further, the heat radiating plate 47 is provided with a thermistor-type lid temperature sensor 57 as lid temperature detecting means for detecting the temperature of the lid 5, particularly the inner lid 51. The lid temperature sensor 57 performs temperature management of the inner lid 51 that is mainly heated by the lid heater 56. A steam port 61 for releasing the steam generated in the pan 11 to the outside is detachably attached to the upper rear portion of the lid 5. Further, an opening hole for passage of steam is formed at a position below the steam port 61 in the heat radiating plate 47 and the inner lid 51, and a steam port packing 62 is provided at the lower end of the steam port 61. It has been.

  Further, an operation panel 63 is provided at the front portion of the outer lid 46. A display substrate 65 is disposed in a substrate storage chamber 64 formed in the lid 5 below the operation panel 63. The time and selected course are displayed on the display substrate 65. An LCD 66 for displaying, an LED 67 for displaying the current process, a switch 68 for starting cooking and selecting a course are mounted. An operation panel 63 corresponding to the operation unit displays button names and the like, and prevents dust and water from adhering to the display unit which is an electronic component. The operation panel 63 may be provided on the front side of the rice cooker body 1.

  71 is a heating control means provided in the interior rear of the rice cooker body 1. The heating control means 71 includes a heating element (not shown) for driving the heating coil 16, which is a heating means, provided on the substrate. The element that drives the heating coil 16 is heated along with the oscillation of the heating coil 16, but has a use condition temperature that guarantees the operating state, and therefore needs to be used at a certain temperature or lower. For this purpose, the element that drives the heating coil 16 is thermally connected to a fin-like radiator 72 made of a material having good thermal conductivity, such as aluminum, and emits from a cooling fan 73 that is a cooling means. The element is driven within the operating condition temperature by applying the wind to the radiator 72 to remove the heat.

  The cooling fan 73 is disposed below or on the side of the radiator 72 attached to the heating control means 71. In addition, at the bottom or side of the rice cooker body 1, the wind that is emitted from the cooling fan 73 and takes heat from the radiator 72 attached to the heating control means 71 is discharged outside the rice cooker body 1. A plurality of holes 74 are provided. The heating control means 71 is accommodated inside the product, that is, in the rice cooker body 1, but may be disposed at any position on the outer periphery of the pan 11. Moreover, you may arrange | position the hole 74 provided in the bottom part or side part of the rice cooker main body 1 in any position. However, in recent years, there is a demand for miniaturization of products, and the heating control means 71 and the cooling fan 73 and the hole 74 for discharging warm air are arranged at substantially opposite positions across the pan 11. Is preferred.

  FIG. 2 is a front view of the operation panel 63. On the surface of the operation panel 63, located on the periphery of the LCD 66, a rice cooking button 63a for instructing the start of rice cooking, a fast cooking button 63b for instructing quick cooking to shorten the rice cooking time than usual, and a course Course button 63c and cooking button 63d as selection means, hour button 63e for instructing to change the hour digit of the current time or reserved time displayed on LCD 66, and minute button for instructing to change the minute digit of current time or reserved time There are provided 63f, a reservation button 63g for instructing reserved rice for starting or ending rice cooking at the reservation time, and a cut button 63h for instructing a cut-off state for canceling the rice cooking or the heat retaining operation. Corresponding to these buttons 63a to 63h, switches 68 are provided on the back side of the operation panel 63, respectively. In this example, the course according to the difference in rice quality such as white rice, non-washed rice, brown rice, germinated brown rice and the same rice quality (white rice), such as sweetness, softness, crispness, and firmness. When the course button 63c and the cooking button 63d are operated, the course according to the difference in taste, the course according to the difference in cooking while having the same rice quality (white rice) such as rice porridge and cooking, etc. A specific course is selected from a plurality of courses.

  On the other hand, as the LED 67 as the display means, here, the rice cooking LED 67a that is lit during cooking, the fast cooking LED 67b that is lit during quick cooking, the warming LED 67c that is lit during warming, and the reserved cooking rice are selected until cooking is started. And a reservation LED 67d that is turned on during standby. The LCD 66 also includes a time display unit 66a for displaying the current time or the reservation time, a first course display unit 66b for displaying a course selected from courses corresponding to differences in rice quality and cooking, and heat-reheating. It is comprised by the heat retention reheating display part 66c which displays that sometimes, and the cooking division display part 66d which displays the hardness or the degree of taste of cooked white rice. The configuration of the operation panel 63 here is merely an example, and various other courses may be provided.

  Next, an electrical configuration in this embodiment is shown in FIG. In the figure, the display / operation unit 75 around the operation panel 63 includes two microcomputers as control means for controlling the operation of each part of the rice cooker instead of one conventional microcomputer. This is a display microcomputer 76 as a first control unit and a load driving microcomputer 77 as a second control unit. The display microcomputer 76 is an 8-bit microcomputer, and the processing speed is slower than that of the load drive microcomputer 77. However, the display microcomputer 76 has low power consumption, and in addition to the input / output unit, storage unit, and control processing unit normally provided as a microcomputer, It is characterized by having a drive control circuit. In particular, since the power consumption when the power supply to the rice cooker main body 1 is cut off and the power consumption is less than 10 μA is used, lithium of about 600 mAh generally used as the built-in battery 78 is used. If it is a battery, it can be provided for 4 years or more without replacement, including the current consumption of peripheral circuits connected to the display microcomputer 76. Using such characteristics, the display microcomputer 76 performs display processing on the LCD 66 including memory backup at the time of a power failure, time count of a clock function, time, and the like. In particular, since the memory backup is performed by receiving power supply from the battery 78 even in the event of a power failure, the display microcomputer 76 also manages the operation of the entire rice cooker. Besides that, the display microcomputer 76 is a rice cooker related to LED 67 display processing, detection of pressing of the switch 68 and processing of each part based on this detection, power failure detection and processing of each part based on this detection, rice cooking and heat insulation The whole control is performed.

  Whether or not the power supply from the commercial power source (not shown) to the rice cooker body 1 is cut off at the input side port of the display / operation unit 75 so that the display microcomputer 76 performs processing based on the detection of the power failure. The power failure detection circuit 79 is detected. When a power failure signal indicating that a power failure has been detected is sent from the power failure detection circuit 79, the display microcomputer 76 that has received this backs up the built-in memory and stores and holds the state immediately before the power failure of each part of the rice cooker. It is like that. A switch 68 is connected to the input side port of the display microcomputer 76, and an LCD 66 and an LED 67 as display means are connected to the output side port of the display microcomputer 76, respectively.

  On the other hand, another load driving microcomputer 77 is a 32-bit DSP (digital signal processor) microcomputer, which consumes more current than the display microcomputer 76 but has a very high speed digital signal processing function. is there. Utilizing such characteristics, IH control related to the heating coil 16 that requires high-speed processing, particularly in a rice cooker, and processing that requires a lot of calculation during rice cooking are performed. For this purpose, the input side port of the load drive microcomputer 77 detects the input voltage, input current, and regenerative current of the inverter that are input to the inverter, and outputs a detection signal to the inverter and the like. A surge detection circuit 82 that detects an unnecessary surge voltage that is generated and a trigger detection circuit 83 that outputs a trigger signal that is the oscillation timing of the heating coil 16 are connected, and the output side port of the load driving microcomputer 77 An inverter oscillation circuit 84 that supplies a high-frequency current to the heating coil 16 is connected. In addition, the load driving microcomputer 77 reads temperature information from the pan temperature sensor 21 and the lid temperature sensor 57 and loads other than the heating coil 16, such as the code heater 26, the lid heater 56, and the cooling fan 73. Drive control is performed. For this purpose, a temperature detection circuit 85 that outputs sensor outputs from the pan temperature sensor 21 and the lid temperature sensor 57 as temperature information is connected to the input side port of the load drive microcomputer 77, and the output side of the load drive microcomputer 77 Connected to the port is a load drive circuit 86 that supplies sufficient power to drive the load 88. Each of these circuits 81 to 86 is provided as a heating circuit 89 that constitutes the heating control means 71.

  As described above, the reason why the plurality of microcomputers 76 and 77 are used as the control means is that, in general, a microcomputer having a high processing speed (for example, the load driving microcomputer 77) consumes a large amount of current. In other words, in this embodiment, a lot of calculations are required to read and process information from each part of the rice cooker, but when trying to perform data backup and clock counting at the time of power failure with a high-speed microcomputer that can process such calculations. Then, a large capacity battery is required to operate the microcomputer even in the event of a power failure, which causes a problem of increasing costs and increasing the size of the rice cooker body 1. Therefore, the drive control of the heating coil 16 and the load 88 that require high-speed processing is configured to be executed by the load drive microcomputer 77 having a high-speed calculation function, and control of other parts of the rice cooker (especially during power failure) The display microcomputer 76 having a low current consumption function is configured to execute a backup function that requires power consumption.

  In order to exchange signals between the two microcomputers 76 and 77, in this embodiment, each of the microcomputers 76 and 77 is provided with a communication unit 90 that realizes three-wire clock synchronous serial communication. The display microcomputer 76 is provided with a clock generation unit 91 that generates a reference clock pulse. From the clock generation unit 91 of the display microcomputer 76 to the load driving microcomputer 77 having a high processing speed, the communication unit 90 is connected. By outputting a clock, communication is synchronized on the load driving microcomputer 77 side. The display microcomputer 76 gives various command signals to the load driving microcomputer 77 when, for example, cooking rice or keeping warm. Specifically, an IH drive command signal indicating how much power the heating coil 16 is driven, a panless detection command signal for checking the presence / absence of the pan 11, and a process of boiling heating 2 described later are executed. For example, a command signal for driving and a load driving command signal indicating how to drive the load 88 are transmitted to the load driving microcomputer 77 via the communication unit 90. On the contrary, the load drive microcomputer 77 transmits temperature information obtained from the temperature detection circuit 85, IH drive error information related to the heating coil 16, and the like to the display microcomputer 76 via the communication unit 90.

  In addition to the serial communication line 92 connected between the communication units 90, a reset transmission line 93 for transmitting a reset signal from the display microcomputer 76 to the load driving microcomputer 77 is provided between the display microcomputer 76 and the load driving microcomputer 77. Connected. The display microcomputer 76 is provided with a reset unit 94 that generates a reset signal for returning the load driving microcomputer 77 from the idle mode to the normal mode. As described above, since the load driving microcomputer 77 consumes more current than the display microcomputer 76, the load driving microcomputer 77 has a circuit configuration in which no current is supplied to the load driving microcomputer 77 during a power failure. For this reason, when the power supply to the rice cooker body 1 is cut off, the display microcomputer 76 operates as it receives the current supply from the battery 78, but the load driving microcomputer 77 stops operating and consumes no current at all. Become. Thereby, the consumption of the battery 78 at the time of a power failure can be suppressed to the minimum. In addition, even during energization when power is supplied to the rice cooker body 1, a certain period of time is required during periods when it is not necessary to drive the heating coil 16 or the load 88, such as when stopped (off state) or when waiting for reserved rice cooking. When (for example, 5 to 60 seconds) elapses, the display microcomputer 76 sends a command to set the load driving microcomputer 77 from the normal mode to the idle (pause) mode by serial communication, and the load driving microcomputer 77 is brought into a low power consumption state.

  As described above, when the load driving microcomputer 77 enters the idle mode after a certain time has elapsed, the information from the voltage / current detection circuit 81 and the temperature detection circuit 85 is transmitted to the display microcomputer 76. This is because the determination of abnormality cannot be made and it is necessary to confirm them in the normal mode for a certain period of time. The load driving microcomputer 77 in the idle mode is released by the reset signal given from the reset unit 94 of the display microcomputer 76, and returns to the normal mode in which information from the voltage / current detection circuit 81, the temperature detection circuit 85, and the like is received. By providing the display microcomputer 76 with a function as the reset unit 94, it is possible to save an increase in cost of separately providing a reset circuit. Moreover, since the idle mode can be easily canceled by the reset signal from the display microcomputer 76, the programs of both the microcomputers 76 and 77 can be simplified. In addition, even when some communication abnormality occurs between the communication lines 92, a reset signal can be output from the reset unit 94 of the display microcomputer 76 to return the load driving microcomputer 77 to the initial state. This communication abnormality refers to a case where the display microcomputer 76 cannot receive a communication message due to noise or the like. If a communication error occurs during rice cooking, the load driving microcomputer 77 cannot be stopped by communication from the display microcomputer 76, so the load driving microcomputer 77 is reset by a reset signal from the display microcomputer 76. In addition, the reset signal is output from the display microcomputer 76 to the load driving microcomputer 77 when the power is restored.

  The heating control means 71 receives temperature detection signals from the pan temperature sensor 21 and the lid temperature sensor 57, and heats the heating coil 16, the flange heater 26, and the lid heater 56, which are heating means, respectively. In particular, the heating control means 71 of the present embodiment mainly controls the heating coil 16 based on the temperature detected by the pan temperature sensor 21 to manage the temperature of the bottom of the pan 11 and based on the temperature detected by the lid temperature sensor 57. Further, the lid heater 56 is controlled to control the temperature of the heat radiating plate 47 and thus the inner lid 51.

  During cooking and warming, the pan 11 is heated by these heating means, but during the warming, the heating means is adjusted by the temperature detected by the pan temperature sensor 21 in contact with the bottom of the pan 11 so that the pan 11 is kept at a constant temperature. It is configured to hold. In particular, supplementary explanation about the heating by the cord heater 26, until the temperature of the rice is lowered from about 100 ° C. to about 73 ° C. after the rice cooking, and when the temperature is stable at about 73 ° C., the code heater 26 is heated, Heat is radiated from the metal plate 29 to the space 30 between the lid 5 and the rice cooker body 1 to suppress cooling due to the intrusion of outside air from the gap 30 and the flange portion 14 of the pan 11 is heated. In addition, the cord heater 26 also heats the flange portion 14 of the pan 11 during the period when the rice is reheated during heat insulation, so that moisture generated by heating the rice is prevented from condensing on the upper part of the inner surface of the pan 11. ing.

  Each course selected by the course button 63c and the cooking button 63d has its own temperature change value and heating time from rice to peanut performed by the rice cooking control means 95, which will be described later, depending on the quality and hardness of the rice. Is set to For example, in the recommended (normal) course, the cooked rice is kept at 35 to 45 ° C for 20 minutes in the process, and until boiling it is about 8 ° C per minute (8 ° C / min), that is, the cooked rice is from 20 ° C to 100 ° C. The target is set so that it takes about 10 minutes to raise the temperature, and the boiling continues for another 5 to 10 minutes. In addition, in the crushing course, the holding time in the process is shorter than the recommended course, and until boiling, about 10 ° C per minute (10 ° C / min), that is, the cooked rice from 20 ° C To raise the temperature to 100 ° C, the target is set to be about 8 minutes shorter than the recommended course, the amount of heating to continue boiling more than the recommended course, and the unevenness time to be shorter than the recommended course. Also, in the soft rice course, the holding time in the process is longer than the recommended course, and until boiling it is about 5 ° C (5 ° C / minute), that is, the cooked rice is heated from 20 ° C to 100 ° C. The target is set to be about 16 minutes longer than the recommended course, lower the amount of heating to continue boiling than the recommended course, and make the unevenness time longer than the recommended course. Furthermore, in the sweetness course, the holding time in the process is lengthened so that the temperature body (for example, 40 to 50 ° C.) on which amylase works is held for a long time, and about 4 ° C. (4 ° C. per minute) until boiling. / Min), that is, to raise the cooked rice from 20 ° C to 100 ° C, increase the working time of the enzyme as about 20 minutes longer than the soft rice course, reduce the amount of heating to continue boiling, and even more uneven And set a goal to increase the time.

  In addition, for courses such as brown rice and rice crackers, the process time, the amount of heating to the pan 11 and the temperature change value until boiling are set independently. Such target set values for the heating time and the temperature change value are merely examples, and may be appropriately changed in consideration of the heating capability and characteristics of the rice cooker, the characteristics of the temperature detection means, and the like.

  Next, the effect | action is demonstrated about the said structure, referring the graph in FIG. In FIG. 4, the horizontal axis represents each control process and elapsed time of rice cooking, and the detected temperatures P1 and P2 of the pan temperature sensor 21 and the lid temperature sensor 57 and the heating amount (power consumption) of the heating coil 16 are respectively shown. Appears. Each of the microcomputers 76 and 77 includes a rice cooking control means 95 as a function on the software, and each control process of rice cooking and heat insulation described later is performed by the rice cooking control means 95 and the storage unit of the microcomputers 76 and 77. The processing is executed in order according to the control program related to the heat retention control means 96.

  A predetermined amount of rice and water is put into the pan 11, the pan 11 is accommodated in the pan container 9 and the lid 5 is closed, and then the rice cooking button 63 a is pressed. When the input signal of the switch 68 corresponding to the rice cooking button 63a is taken into the display microcomputer 76, rice cooking by the rice cooking control means 95 is started, and first a process of infiltrating water to the core of the rice is performed. In the process, the heating coil 16 is cut off in a predetermined pattern, and the pan 11 is heated for the first time (see screens 1 and 2 in FIG. 4), and then the heating is stopped for a certain time. (Refer to FIG. 4.) And based on the raise value of the detected temperature P1 from the pan temperature sensor 21 at the time of initial heating, and the fall value of the detected temperature P1 at the time of a subsequent heating stop, the rice cooking capacity in the pan 11 is determined.

  When the capacity determination is completed, the rice cooking control means 95 controls the heating coil 16 to be turned on and off so that the detected temperature P1 of the pan temperature sensor 21 is maintained at a constant temperature, and causes the rice in the pan 11 to absorb water (see FIG. 4 see 4). Then, after a predetermined holding time corresponding to the above-described course has elapsed, the process is terminated and the process proceeds to a boiling heating process.

  At the beginning of the boiling heating process (refer to boiling heating 1 in FIG. 4), first, full energization is performed at 1100 to 1300 W, which is the maximum output of the heating coil 16, and the rate of temperature increase during that time is read from the pan temperature sensor 21. The rice cooking control means 95 detects empty cooking in the pan 11 and the pan temperature sensor 21 detects abnormality.

  Then, regardless of the rice cooking capacity, when the boiling heating 1 is 70 seconds or more, which is a predetermined time, or the detected temperature P1 of the pan temperature sensor 21 is 70 ° C. or more, the rice cooking control means 95 performs the next boiling heating 2 To do. When the boiling heating 2 is entered, the rice cooking control means 95 first sets the target temperature Ta of the lid temperature sensor 57 based on the following equation (1).

上記数１において、目標温度Ｔａは、単位時間当たりの温度上昇率ａと、沸騰加熱２の開始時からの経過時間（単位：秒）ｔとの積に、沸騰加熱２の開始時における蓋温度センサ57の検出温度Ｔ₀を加えて算出される。これにより、ある時間ｔ毎における目標温度Ｔａが定まる。目標温度上昇率ａは前述の選択したコースや炊飯容量によって異なり、例えば硬めの炊き上がりをさせるコースでは大きな値（急な温度勾配）となり、やわらかめの炊き上がりをさせるコースでは小さな値（なだらかな温度勾配）となる。なお、目標温度ａとして蓋温度センサ57を用いるのは、鍋温度センサ21で検出する鍋11の底面の温度よりも、蓋温度センサ57で検出する蓋体51の温度が、鍋11内の被炊飯物の温度に近いためである。即ち、加熱コイル16により鍋11を電磁誘導加熱するものでは、鍋11の発熱体13が直接発熱するので、鍋11内部との温度差が大きいが、内蓋51は加熱コイル16による熱影響を直接受けないので、その分被炊飯物の温度を精度よく検出できる。但し、鍋温度センサ21の検出温度Ｐ１と鍋11内部の温度との相関が予め判っていれば、鍋温度センサ21を目標温度と定めて加熱制御を行なってもよい。また、時間ｔと目標温度Ｔａとの相関は、前記数１に示すものに限られない。

In the above equation 1, the target temperature Ta is the product of the temperature increase rate a per unit time and the elapsed time (unit: seconds) t from the start of the boiling heating 2, and the lid temperature at the start of the boiling heating 2 It is calculated by adding the detection temperature T ₀ of the sensor 57. Thereby, the target temperature Ta for every certain time t is determined. The target temperature increase rate a varies depending on the selected course and rice cooking capacity. For example, the target temperature rise rate a has a large value (steep temperature gradient) in a course that cooks hard, and a small value (smooth in a course that cooks softly). Temperature gradient). Note that the lid temperature sensor 57 is used as the target temperature a because the temperature of the lid 51 detected by the lid temperature sensor 57 is higher than the temperature of the bottom surface of the pan 11 detected by the pot temperature sensor 21. This is because it is close to the temperature of the cooked rice. That is, in the case where the pan 11 is heated by electromagnetic induction by the heating coil 16, the heating element 13 of the pan 11 directly generates heat, so the temperature difference from the inside of the pan 11 is large. Since it is not directly received, the temperature of the cooked rice can be accurately detected accordingly. However, if the correlation between the detected temperature P1 of the pan temperature sensor 21 and the temperature inside the pan 11 is known in advance, the pan temperature sensor 21 may be set as the target temperature to perform the heating control. Further, the correlation between the time t and the target temperature Ta is not limited to that shown in the above equation 1.

  When the rice cooking control means 95 sets the target temperature Ta, the rice cooking control means 95 reads the target temperature at which the detected temperature P2 of the lid temperature sensor 57 read every predetermined time (for example, 1 second) is a set temperature change value. The output control of the heating coil 16 based on the following equation 2 is performed along Ta.

上記数２において、今回加熱コイル16に与える出力ワットＷ_n+1（Ｗ_nは前回加熱コイル16に与えた出力ワット）は、沸騰加熱２の開始時に加熱コイル16に与えた出力ワットに、各回毎に計算される調整ワットδＷを加えて算出される。また調整ワットδＷは、比例制御による調整ワットδＷ_pと、積分制御による調整ワットδＷ_iと、微分制御による調整ワットδＷ_dとをそれぞれ加算して算出される（δＷ＝δＷ_p＋δＷ_i＋δＷ_d）。なお、調整ワットδＷの要素としては、各調整ワットδＷ_p，δＷ_i，δＷ_dの少なくとも何れか一つが含まれていればよい。

In the above equation 2, the output wattage W _{n + 1} (W _n is the output watt previously given to the heating coil 16) given to the heating coil 16 this time is the same as the output watt given to the heating coil 16 at the start of boiling heating 2 each time. It is calculated by adding the adjustment wattage δW calculated every time. The adjusted watt δW is calculated by adding the adjusted watt δW _p by proportional control, the adjusted watt δW _i by integral control, and the adjusted watt δW _d by differential control, respectively (δW = δW _p + δW _i + δW _d ). . As an element of the adjustment watt δW, at least one of the adjustment watts δW _p , δW _i , and δW _d may be included.

The adjusted wattage δW _p by proportional control is the difference between the target temperature Ta calculated at the current time (t = n) calculated by the above equation 1 and the actual detected temperature P2 read from the lid temperature sensor 57 (e _n = Ta-P2), and if the constant that determines how much the target temperature Ta, which is the target value, is approached by K _p , the adjustment watt δW _p is equal to the constant K _p and the temperature difference represented by product of _{e n (δW p = K p} × e n). Accordingly, as the difference between the target temperature Ta and the detected temperature P2 at this time is large, even larger values of the adjustment watts .delta.W _p calculated in proportion to this, the pot 11 quickly the target temperature Ta The output watt control of the heating coil 16 so as to approach is performed at regular time intervals when the detection temperature P2 of the lid temperature sensor 57 is taken.

The adjustment wattage δW _i by integration control is the difference between the target temperature Ta up to the previous i times and the actual detected temperature P2 read from the lid temperature sensor 57 when the detected temperature P2 is read from the lid temperature sensor 57 this time. Adjustment constant wattage δW, where K _i is a constant that determines how much the target temperature Ta, which is the target value, approaches the target temperature Ta, and is an adjustment amount proportional to the total sum of (Σe _ni = Σ (Ta−P2)). _i is represented by the product of the cumulative total of Sigma] e _ni temperature difference and the constant _{K i (δW p = K p} × e n). As a result, the larger the integrated sum Σe _ni of the difference between the target temperature Ta and the detected temperature P2 up to a certain time, the larger the value of the adjustment watt δW _i calculated in proportion to this, and the past several times Considering the accumulation of the difference between the temperature Ta and the detected temperature P2, the output watt control of the heating coil 16 that quickly brings the inside of the pan 11 close to the target temperature Ta takes a certain time to take in the detected temperature P2 of the lid temperature sensor 57 Every time. In particular, the only adjustment watts .delta.W _p by proportional control, when calculating the output wattage W _{n + 1} to the heating coil 16, but results in errors in the actual pot 11 internal temperature and the target temperature Ta that changes from moment to moment, If the adjustment wattage δW _i by integration control is taken into account, the output watt W _{n + 1} is calculated in consideration of the accumulation of the difference between the target temperature Ta and the detected temperature P2 in the past several times. Thus, it becomes possible to approach the target temperature Ta.

The adjustment watts .delta.W _d by differential control, when reading the detected temperature P2 from the current lid temperature sensor 57, and this current actual value obtained by subtracting the detected temperature P2 from the target temperature Ta (e _n), the last m times the difference between the - _(m e _n) actual a subtracted value detected temperature P2 of the front past m times from the previous target temperature Ta - an adjustment amount which is proportional to (e _n -e _{n m),} is the target value When a constant that determines how close in how much strength the target temperature Ta and K _d, the adjustment watts .delta.W _d is the the constant K _d difference (e _n -e _n - _m) indicated by the product of (.delta.W _{d = K d × (e n -e} n - m)). The difference (e _n -e _n - _m) is how much momentum indicates whether approaching the target value of the momentum to approach the target temperature Ta is low, adjustment watts calculated in proportion to If the value of δW _d increases and conversely the momentum approaching the target temperature Ta is strong, the value of the adjustment watt δW _d is set to suppress the actual temperature in the pan 11 from exceeding the target temperature Ta and overshooting. Make it smaller. Thus, in consideration of the momentum in which the temperature in the pan 11 approaches the target temperature Ta, the output watt control of the heating coil 16 that quickly brings the inside of the pan 11 close to the target temperature Ta is used to set the detected temperature P2 of the lid temperature sensor 57 to This is done at regular intervals.

The calculation of the target temperature Ta for each predetermined time and the calculation of the respective adjusted watts δW _p , δW _i , δW _d and the output watt output watt W _{n + 1} at that time are all arithmetic processing units of the load control microcomputer 77 (see FIG. (Not shown). When performing such calculation, the display microcomputer 76 sends the load control microcomputer 77 a command to perform boiling heating 2 and the control parameters thereof include the target temperature increase rate a and the constants K _p , K _i , K _d. Send.

  FIG. 5 conceptually shows the control method of the rice cooking control means 95 in this embodiment. In this figure, in this embodiment, a target temperature Ta with time t as a parameter is set in advance, and the output watt of the heating coil 16, that is, the amount of heating to the pan 11 is brought close to the target temperature Ta that changes every time t. However, it is variably controlled every time the temperature inside the pan 11 is read. Therefore, conventionally, for example, fixed output watts of about 10 stages (for example, 500 W, 600 W, 700 W... 1400 W) are prepared in advance, and data for outputting the output watts (the ON time width and amplitude of the pulse applied to the oscillation circuit 83) However, in this example, the data for calculating the output watt is calculated every time the temperature inside the pan 11 is read, and the output watt of the heating coil 16 is not calculated. Variable in stages. For example, when an output watt of 630 W is required, 600 W and 700 W of the conventional data table are interpolated to calculate data for outputting the output watt. In this way, in this embodiment, regardless of the amount of cooked rice, the temperature in the pan 11 can be brought close to the target temperature Ta, and the actual heating by the heating coil 16 can be made to substantially match the ideal heating.

  In the boiling heating 2 described above, the rice cooking control means 95 is loaded from the voltage / current detection circuit 81 using the load driving microcomputer 77 until the detected temperature P2 of the lid temperature sensor 57 is changed from 60 ° C. to 80 ° C. Based on the input voltage and input current of the inverter, the power consumption (integrated power consumption) of the heating coil 16 is calculated. The calculation result of the integrated electric energy calculated by the product of the input voltage, the input current, and time is transmitted to the display microcomputer 76 through the serial communication line 92 as needed. When the display microcomputer 76 receives this via the communication unit 90, the display microcomputer 76 stores it in the internal storage unit. When the power supply to the rice cooker body 1 is cut off due to a power failure, the accumulated power amount data by the load driving microcomputer 77 is cleared, but the display microcomputer 76 receives the power supply from the battery 78 and stores the contents of the storage unit. Therefore, after the power failure is restored, the integrated power amount before the power failure stored in the storage unit can be added to the integrated power amount by the load driving microcomputer 77 to obtain the correct integrated power amount.

  Further, since the output watts of the heating coil 16 controlled by the load driving microcomputer 77 are adjusted one by one at the time of factory shipment, the actual output watts do not greatly change. In this embodiment, the output watts of the heating coil 16 can be adjusted by operating the switch 68 in a special pattern to activate a special mode that is different from normal rice cooking and heat retaining operations. The output adjustment means 98 provided as the above operates and a pulse that causes the heating coil 16 to output at a rated wattage (for example, 1250 W) is loaded under the condition that a rated power supply voltage (for example, AC100V) is supplied to the rice cooker body 1. It is supplied from the driving microcomputer 77 to the oscillation circuit 83. At this time, the output watt of the heating coil 16 is calculated from the input voltage and input current taken in from the voltage / current detection circuit 81, and the on-time width and amplitude of the pulse are adjusted so that this becomes the rated watt. Then, software adjustment (correction) is performed by the output adjustment means 98 so that the adjusted pulse is recognized as a drive signal to the oscillation circuit 83 at the rated watt hour. However, this may be performed in hardware by a variable resistor that adjusts the amount of current to the heating coil 16.

  In the subsequent rice cooking and heat insulation performed by the rice cooking control means 95 and the heat retention control means 96, when performing output at a certain watt, a pulse having an appropriate on-time width and amplitude calculated based on the drive signal is sent to the oscillation circuit 83. Supply. Even if the power supply voltage fluctuates, the actual output watt at this time is read from the voltage / current detection circuit 81, and the on-time width and amplitude of the pulse to the oscillation circuit 83 are varied so that this becomes the watt to be output. The output watt of the heating coil 16 is kept constant. By doing so, it becomes possible to supply the heating amount to the pan 11 with a correct wattage output regardless of the fluctuation of the power supply voltage.

  The calculated integrated power amount of the heating coil 16 is used by the rice cooking control means 95 for reconfirmation of the rice cooking capacity. The reason is that the amount of integrated power until the detected temperature P2 is changed from 60 ° C. to 80 ° C. depends on the size of the rice cooking capacity in the pan 11. For example, if it is determined that the rice cooking capacity is small in the above-mentioned process, but it is reconfirmed that the rice cooking capacity is large due to the integrated power consumption calculated thereafter, there may be an error in the determination in the process Because there is, determine the final cooking rice capacity to medium amount or large amount again. On the other hand, if it is determined that the rice cooking capacity is large in the process, but if it is reconfirmed that the rice cooking capacity is low according to the calculated integrated power consumption, the final rice cooking capacity is reduced to medium or small. Re-determine. In this way, even if the rice cooking amount is erroneously determined in the process, the correct rice cooking capacity can be determined based on the accumulated power amount data for the heating coil 16 thereafter. In addition, because the rice cooking capacity can be correctly determined before boiling, the cooked rice can be boiled with a heating amount suitable for the cooking rice capacity, and the spillage caused by inappropriate heating amount or the paste of the cooked rice due to insufficient heating Insufficiency can be prevented.

  The rice cooking control means 95 stands by in the state of boiling heating 2 until the detected temperature P2 of the lid temperature sensor 57 taken in from the display microcomputer 76 is the temperature immediately before boiling, preferably 95 ° C (80-100 ° C), When this temperature is reached, the next boiling heating 3 is started. In the boiling heating 3, a predetermined constant heating of, for example, 500 to 1100 W is applied to the pan 11 so that stable boiling detection can be performed. Thus, when the rate of temperature increase of the detected temperature P2 of the lid temperature sensor 57 becomes less than the predetermined temperature (1 to 5 ° C.) within a predetermined time (for example, 30 to 150 seconds), that is, the temperature gradient of the detected temperature P2 is sufficiently small. When it becomes, the boiling in the pan 11 is detected, and the rice cooking control means 95 ends the boiling heating process and shifts to the next boiling continuing process.

  In the boiling continuation, the heating to the pan 11 by the heating coil 16 is repeated with a predetermined on / off switching pattern. And when a certain amount of time passes, the water in the pan 11 evaporates and the temperature gradually rises. In particular, in cooking, since the temperature of the bottom of the pan 11 rises rapidly, the detected temperature P1 is a predetermined temperature (+2 to 10 ° C.) with respect to the detected temperature P1 of the pan temperature sensor 21 when boiling is detected. If it rises above, the rice cooking control means 95 will consider that the inside of the pan 11 is in a cooked (dry-up) state, and will move to the next uneven process. In the unevenness process, the pan is turned off while the heating coil 16 is turned off so that the detected temperature P1 of the pan temperature sensor 21 maintains a predetermined temperature (for example, 95 to 110 ° C.) for a predetermined time (for example, 6 to 16 minutes). Heat 11. When the unevenness process for a predetermined time is thus completed, the process proceeds to a heat insulation process by the heat insulation control means 96 instead of the rice cooking control means 95.

  In the heat insulation process, the bottom and side lower portions of the pan 11 are heated by the heating coil 16, and the inner lid 51 is heated slightly higher than the temperature of the rice in the pan 11 by the lid heater 56. Heating is performed by the heater 26, and the temperature is controlled so that the rice in the pan 11 is not dried and a large amount of dew does not adhere to the side surface of the pan 11. The temperature of the rice is maintained at 70 to 76 ° C. except for reheating.

  As described above, in this embodiment, the heating coil 16 as a heating means for heating the pan 11, the lid temperature sensor 57 as a temperature detection means for detecting the temperature in the pan 11, and the target temperature Ta or the target temperature increase rate Is set in proportion to the difference between the control temperature (target temperature Ta) and the detected temperature P2 of the lid temperature sensor 57, or until a predetermined time before the detected temperature P2 of the lid temperature sensor 57. The amount of difference between the control temperature and the detected temperature P2 of the lid temperature sensor 57 is calculated in proportion to the amount obtained by integrating the difference between the current time and the predetermined temperature, and in proportion to the difference between the two amounts. The rice cooking control means 95 is provided as control means for adjusting the heating amount of the heating coil 16.

  In this case, for example, when heating the pan 11 such as boiling heating, the rice cooking control means 95 first sets a control temperature that varies with time. Thereafter, every time the rice cooking control means 95 takes in the detected temperature p2 from the lid temperature sensor 57, the difference between the control temperature and the detected temperature P2 in proportion to the difference between the control temperature and the detected temperature P2 or until a certain time before is detected. The amount of difference between the control temperature and the detected temperature P2 a certain time before this time or the detected temperature P2 is calculated, respectively, and the amount of heating of the heating coil 16 is proportional to the difference between the two amounts. adjust. In this way, since the control of the heating coil 16 that brings the inside of the pan 11 quickly to the target control temperature is performed every time the detection temperature P2 of the lid temperature sensor 57 is taken in, the pan 11 is heated as ideal. It is possible to improve the variation in temperature change and improve the cooking without being influenced by various factors.

  Moreover, the rice cooking control means 95 of the present embodiment is composed of microcomputers 76 and 77 which are a plurality of control units. If it carries out like this, the rice cooking control means 95 which controls operation | movement of each part of a rice cooker will be comprised by the some microcomputer 76,77 like hardware. In this way, each function of the rice cooking control means 95 can be distributed to a plurality of microcomputers 76 and 77 without concentrating each function on one control unit, and the optimum control according to the processing capacity of each function The microcomputers 76 and 77 can be used.

  Further, in this embodiment, as the plurality of control units, a display microcomputer 76 as a first control unit having a low current consumption function and a load driving microcomputer 77 as a second control unit having a high-speed calculation function are provided. It is configured.

  In this case, calculation of the heating amount of the heating coil 16, which requires a lot of processing, is performed by the load driving microcomputer 77 having a high-speed calculation function, and a low current consumption function is provided for other simple processing. The display microcomputer 76 can be used. Thereby, rice cooking can be performed as intended by high-speed calculation processing by the load driving microcomputer 77. Further, if only the display microcomputer 76 is backed up by the battery 78 in the event of a power failure, the life of the battery 78 can be extended.

  In this embodiment, the load driving microcomputer 77 is reset by the display microcomputer 76. In this way, the reset operation of the load driving microcomputer 77 can be performed by the reset signal from the display microcomputer 76, and there is no need to provide a separate reset circuit. Therefore, the part cost inside the rice cooker can be suppressed, and the reliability of the product can be improved by further simplifying the program.

  In addition, this invention is not limited to said each Example, A various deformation | transformation implementation is possible. For example, the numbers of time and temperature in the examples are merely examples, and both can be read as a predetermined time or a predetermined temperature. Further, there may be three or more microcomputers as control units.

It is sectional drawing of the rice cooker in the preferable Example of this invention. It is a front view of an operation panel same as the above. It is a block diagram which shows an electrical structure same as the above. It is a graph which shows the temperature change of the pan temperature sensor and lid | cover temperature sensor at the time of rice cooking, and the heating amount of a heating coil same as the above. It is a graph which shows the change of the rice temperature at the time of a heating, and a heating amount same as the above. It is a graph which shows the change of the rice temperature at the time of the heating in a prior art example, and a heating amount.

Explanation of symbols

11 Pot
16 Heating coil (heating means)
57 Lid temperature sensor (temperature detection means)
76 Display microcomputer (control unit, first control unit)
77 Load-driven microcomputer (control unit, second control unit)
95 Rice cooking control means (control means)

Claims (4)

A heating means for heating the pan, a temperature detecting means for detecting the temperature, and a control temperature which is a target temperature or a temperature rise rate are set, and is proportional to the difference between the control temperature and the detected temperature of the temperature detecting means. Or in proportion to an amount obtained by integrating the difference between the control temperature up to a certain time before and the detection temperature of the temperature detection means, or the control temperature and the detection temperature of the temperature detection means before this time and a certain time And a control means for adjusting the heating means in proportion to the difference between the two quantities. 2. The rice cooker according to claim 1, wherein the control means comprises a plurality of control units. The said control part has a 1st control part provided with the low consumption function, and a 2nd control part provided with the high-speed calculation function, The rice cooker of Claim 2 characterized by the above-mentioned. The rice cooker according to claim 3, wherein the second control unit is reset by the first control unit.

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