Rice cooker

Abstract

To provide a rice cooker capable of cooking rice with heating close to that in cooking with a rice pot.SOLUTION: A rice cooker includes: a pot 7 for containing rice to be cooked; a bottom surface heater 11 for heating the pot 7; rice cooking control means 41 for cooking the rice by varying the amount of heating of the bottom surface heater 11 along with proceeding of a process; and heating amount fluctuation means 44 for changing the amount of heating of the bottom surface heating body 11 with time. The process includes a soaking cooking step, a heating step up to boiling, a heating step while boiling is continuing, and a steaming step. The heating amount fluctuation means 44 varies the amount of heating of the bottom surface heating body 11 so as to periodically repeat an upper limit of the amount of heating, a lower limit of the amount of heating, one or more heating amount values between the upper limit and lower limit of the amount of heating in two or more steps of the soaking cooking step, the heating step up to boiling, the heating step while boiling is continuing, and the steaming step. The upper limit and lower limit of the amount of heating and the length of a cycle vary and a time of maintaining one amount of heating in the cycle varies in accordance with the length of the cycle.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a rice cooker that cooks rice by varying the amount of heat from a heating means while a pot is being heated. [Background technology]

[0002] When cooking rice using a firewood stove, the flames of the firewood flicker, subtly changing the heat, heating the bottom and sides of the pot containing the food to be cooked.

[0003] Known technologies for approaching this traditional cooking in a stove include, for example, Patent Documents 1 and 2, in which three independent induction heating (IH) coils are placed from the bottom to the sides of the pot, and heating is performed by turning electricity on and off while rotating each coil in turn; Patent Documents 3, 4, and 5, in which independent coils at different heights are placed on the bottom and sides of the pot, and heating is performed by alternately turning electricity on and off each coil; Patent Documents 6 and 7, in which induction heating coils are placed from the bottom to the sides of the pot, and the amount of heat of the coils is changed stepwise over time to heat; and Patent Documents 8 and 9, in which induction heating coils are placed from the bottom to the sides of the pot, and the amount of heat of the coils is changed continuously over time to heat. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-162250 A [Patent Document 2] JP 2019-180533 A [Patent Document 3] Japanese Patent Application Publication No. 9-248242 [Patent Document 4] JP 2011-206142 A [Patent Document 5] Japanese Patent Application Publication No. 5-337042 [Patent Document 6] JP 2013-247972 A [Patent Document 7] JP 2008-220470 A [Patent Document 8] Japanese Patent Application Publication No. 11-214139 [Patent Document 9] JP 2020-4540 A Summary of the Invention [Problem to be solved by the invention]

[0005] The above-mentioned conventional technology promotes water convection in the pot during cooking, and heats the rice in the pot with water present evenly, to gelatinize the rice evenly throughout the pot, and is presumably based on an important point for beautifully cooking rice seen in traditional stove-cooking. However, in stove-cooking, the firewood that serves as the heat source is located away from the pot, and indirect heating is performed with an air layer in between, causing the amount of heat given to the pot to fluctuate, whereas in the above-mentioned IH rice cooker, the pot generates heat, so there is no space between the heat source and the pot, and the heating form itself is different.

[0006] In addition to the induction type, there are also other types of rice cookers, such as hot plate heaters that heat a hot plate that comes into contact with the bottom of the pot, radiant heaters that heat the pot with a heater spaced apart from the pot, and indirect cooking types that cook rice by putting water between the pot and the outer pot, but none of these have been able to produce a fluctuating amount of heat applied to the pot like a kamado rice cooker.

[0007] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a rice cooker that can cook rice with heating similar to that of a stove. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the rice cooker of the present invention comprises a pot for containing the food to be cooked, a heating means for heating the pot, a rice cooking control means for changing the amount of heat of the heating means as the process progresses to cook the food, and a heat amount varying means for changing the amount of heat of the heating means over time, the processes including a soaking cooking process, a heating process to boiling, a heating process while boiling continues, and a steaming process, and the heat amount varying means changes the amount of heat of the heating means so as to cyclically repeat an upper limit value of the heat amount, a lower limit value of the heat amount, and one or more heat amount values ​​between the upper limit value and the lower limit value in at least two or more of the soaking cooking process, the heating process to boiling, the heating process while boiling continues, and the steaming process, and the upper limit value, the lower limit value, and the length of the cycle are different, and the time for which one heat amount is maintained in the cycle differs depending on the length of the cycle. Effect of the Invention

[0009] According to the rice cooker of the present invention, rice can be cooked with heating similar to that of a stove. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic explanatory diagram of a rice cooker showing one embodiment of the present invention. [Diagram 2] FIG. 2 is a block diagram showing the electrical configuration of the rice cooker according to the first embodiment. [Diagram 3] 13 is a graph showing the change over time in temperature of the bottom of the pot, the temperature of the underside of the lid, and the amount of heat from the bottom heater. [Figure 4] Graphs showing (A) the change over time in the amount of heat applied to the pot by the rice cooking control means and (B) the change over time in the amount of heat applied to the pot by the heat amount fluctuation means. [Diagram 5] 13 is a graph showing the change over time in the amount of heat applied to the pot by the heat amount fluctuation means. [Figure 6] 4 is a graph showing the change in temperature of each part over time during the boiling heating process. [Figure 7]4 is a graph showing the change in temperature of each part over time during the boiling heating process. [Figure 8] 4 is a graph showing the change in temperature of each part over time during the boiling heating process. [Figure 9] 13 is a graph showing the relationship between the amount of heat and time when heated to high heat. [Figure 10] The same graph shows the relationship between the amount of heat and time at medium heat. [Figure 11] 13 is a graph showing the relationship between the amount of heat and time at low heat. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, preferred embodiments of the rice cooker according to the present invention will be described with reference to the accompanying drawings. In addition, common parts are designated by common reference numerals throughout the drawings.

[0012] First, the overall configuration of the rice cooker in this embodiment will be described with reference to Fig. 1. Reference numeral 1 denotes a main body with an open top, and reference numeral 2 denotes an openable lid that covers the open top of the main body 1, and the appearance of the rice cooker is made up of the main body 1 and the lid 2. On the front side of the main body 1, there is disposed a display operation unit 5 which collectively arranges a display section 3 such as an LED or liquid crystal display, which will be described later, and an operation section 4 such as operation keys or a touch panel. The display operation unit 5 may be disposed on the lid 2 instead of the main body 1.

[0013] A cylindrical pot 7 with a bottom for containing rice and water as food to be cooked A is detachably provided inside the main body 1. When the lid 2 is opened from the main body 1, the pot 7 can be taken in and out from the opening on the top of the main body 1, and when the pot 7 is placed in the main body 1 and the lid 2 is closed, an inner lid 8 attached to the underside of the lid 2 covers the upper surface of the opening of the pot 7, forming an inner pot space 9 surrounded by the inner side of the pot 7, the upper surface of the food to be cooked A, and the underside of the inner lid 8 inside the main body 1 and the pot 7. Although not shown, the pot 7 is mainly made of aluminum, which has good thermal conductivity, and a heating element made of a magnetic material such as ferritic stainless steel is joined to the outer surface of the main material from the lower side to the bottom.

[0014] Inside the main body 1 and outside the pot 7, a bottom heating element 11 using a heating coil and a side heating element 12 using a cord heater are disposed as heating means for heating the pot 7 to cook the food A. The bottom heating element 11, which serves as the main heating means for the pot 7, is disposed facing the bottom part from the lower part of the side where the heating element of the pot 7 is disposed. With this, when the bottom heating element 11 is supplied with a high-frequency current and is in a so-called energized state, the heating element of the pot 7 is heated by the alternating magnetic field from the bottom heating element 11, and the temperature of the pot 7 rises to heat the food A. The side heating element 12, which serves as the auxiliary heating means for the pot 7, is disposed facing the upper part of the side of the pot 7, and when the side heating element 12 is in a energized state, the radiant heat from the side heating element 12 heats mainly the upper part of the side of the pot 7. Side heating element 12 may be configured with a heating coil like bottom heating element 11, and the upper side of pot 7 may be heated by electromagnetic induction in addition to the lower side to the bottom of pot 7. Also, pot 7 may be heated by a heating method other than electromagnetic induction.

[0015] Also provided inside main body 1 is a thermistor-type pot temperature sensor 15 that abuts against the outer surface of the bottom of pot 7. Pot temperature sensor 15, which serves as a pot temperature detection means, detects the temperature of the bottom of pot 7 and primarily controls the heating temperature of the bottom of pot 7 by bottom heating element 11.

[0016] During cooking and keeping warm, the pot 7 is heated by the heating means, and during keeping warm, the bottom heating element 11 is heated and adjusted according to the temperature detected by the pot temperature sensor 15 in contact with the outer bottom surface of the pot 7, to keep the pot 7 at a constant temperature. After cooking, until the temperature of the rice in the pot 7 drops to the keeping warm temperature (from about 100°C to about 73°C) and when the temperature is stable (about 73°C), the side heating element 12, which serves as the heat generating means, is made to generate heat, suppressing cooling caused by outside air entering through the gap between the main body 1 and the lid 2, and heating mainly the upper side of the pot 7. Furthermore, during keeping warm, the pot 7 is heated during the period when hot reheating is being performed to reheat the rice in the pot 7, preventing moisture generated by heating from condensing on the upper inner surface of the pot 7.

[0017] The lid body 2, which opens and closes the upper opening of the pot 7, is equipped with a thermistor-type lid temperature sensor 16 that detects the temperature of the inner lid 8 and therefore the space inside the pot 9, a pressure sensor 17 that detects the internal pressure of the pot 7, and a lid heating body 18 such as a cord heater. The lid temperature sensor 16 and the lid heating body 18 mainly control the temperature of the inner lid 8 by the lid heating means 23, and when the inner lid 8 is attached to the lid body 2, the lid temperature sensor 16 comes into contact with the upper surface of the inner lid 8, and the lid heating body 18 is disposed opposite the upper surface of the inner lid 8. The lid heating body 18 may be composed of a heating coil and the inner lid 8 may be composed of a magnetic member, so that the inner lid 8 can be heated by electromagnetic induction.

[0018] A pressure regulating valve 20 including a ball-shaped valve body 19 is disposed approximately in the center of the inner lid 8 constituting the underside of the lid body 2. The pressure regulating valve 20 is disposed midway through the steam passage space that communicates between the pot interior space 9 and the lid body 2 and ultimately the outside of the rice cooker (outside the machine), and a movable mechanism (not shown) such as a solenoid that moves the valve body 19 forward or backward into or out of the pressure regulating valve 20 is provided inside the lid body 2. With this configuration, when the valve body 19 advances into the pressure regulating valve 20 to block the steam passage space, the pot interior space 9 can be pressurized to above atmospheric pressure until the pressure in the pot interior space 9 increases as the pot 7 is heated and pushes up the valve body, and when the valve body 19 retreats from the pressure regulating valve 20 to open the steam passage space, the pot interior space 9 can be maintained at atmospheric pressure regardless of the heating of the pot 7. The pressure sensor 17 is provided inside the lid 2 facing the pressure regulating valve 20, but it may be provided in another location as long as it can detect the pressure in the pot interior space 9.

[0019] FIG. 2 shows the electrical configuration of the rice cooker in this embodiment. In the figure, 31 is a control unit that is built into the main body 1 and the lid 2 and includes a microcomputer and drive elements for each unit. The input port of the control unit 31 is electrically connected to the operation unit 4, the pan temperature sensor 15, the lid temperature sensor 16, and the pressure sensor 17. The output port of the control unit 31 is electrically connected to the display unit 3, the first heating drive unit 32 connected to the bottom heating element 11, the second heating drive unit 33 connected to the side heating element 12, and the third heating drive unit 34 connected to the lid heating element 18. The control unit 31 is built with a storage means 35 such as a readable and writable memory that stores various information and data.

[0020] The control unit 31 has a function of receiving an operation signal from the operation unit 4 and each of the detection signals from the pot temperature sensor 15, the lid temperature sensor 16, and the pressure sensor 17, outputting a display control signal to the display unit 3 at a predetermined timing based on the timing from a built-in timing means (not shown), and also outputting a heating control signal to each of the first heating drive unit 32, the second heating drive unit 33, and the third heating drive unit 34. These functions are realized by the control unit 31 reading a program pre-recorded in the storage means 35 as a storage medium, and particularly in this embodiment, the control unit 31 is provided with a program that mainly functions as rice cooking control means 41 that heats the rice and water, which are the food A in the pot 7, during cooking to cook rice, and heat keeping control means 42 that maintains the rice in the pot 7 at a predetermined heat keeping temperature during keeping warm.

[0021] The first heating drive unit 32 includes a power supply circuit 36, an inverter 37, and an IH drive circuit 38 as main components. The power supply circuit 36 ​​corresponds to a rectifying and smoothing circuit that converts a commercial power supply voltage of, for example, 100V AC supplied to the main body 1 into a DC voltage, and the DC voltage from the power supply circuit 36 ​​is applied to the inverter 37 as an input voltage. Although neither is shown, the inverter 37 is a well-known voltage-type resonant inverter that includes a resonant capacitor that is connected in parallel with the heating coil that serves as the bottom heater 11 to form a resonant circuit, and a switching element such as an IGBT that is connected in series with the resonant circuit. The IH drive circuit 38 receives the first heating control signal from the control unit 31 and sends a pulse drive signal sufficient to turn on and off the switching element of the inverter 37 to the gate of the switching element. As a result, when a pulse drive signal is applied from IH drive circuit 38 to the gate of the switch element, the emitter-collector of the switch element is repeatedly switched on and off, so that the power supply voltage from power supply circuit 36 ​​is intermittently applied to the resonant circuit of inverter 37, and high-frequency current is supplied to bottom heater 11. At this time, by changing the period of the pulse drive signal and the ratio of on time to one period (on time ratio), the output power (output) from inverter 37, and therefore the amount of heat from bottom heater 11 to pot 7, can be increased or decreased.

[0022] The second heating drive unit 33 receives a second heating control signal from the control unit 31 and supplies the commercial power supply voltage to be applied to the power supply circuit 36 ​​to the cord heater which constitutes the side heating body 12. Similarly, the third heating drive unit 34 receives a third heating control signal from the control unit 31 and supplies the commercial power supply voltage to be applied to the power supply circuit 36 ​​to the cord heater which constitutes the lid heating body 18. Note that the control unit 31 also has a function of sending another control signal to a drive unit of a solenoid which moves the valve body 19, for example, for turning the solenoid on and off; however, as this is not particularly relevant to this embodiment, further explanation and illustration will be omitted.

[0023] The rice cooking control means 41, upon receiving an instruction to start cooking rice via operation of the operating unit 4, sequentially carries out each of the steps of soaking cooking, which promotes the absorption of water by the rice in the food A placed in the pot 7, boiling heating, which brings the temperature of the food A to a boil in a short period of time and then keeps the food A boiling to bring it to a water-free dried-up state, and steaming, which maintains the temperature of the food A in the dried-up state at a high temperature but not so high that it burns, and cooks the food A contained in the pot 7 at the desired pressure. In this embodiment, for all cooking courses that can be used by the rice cooker to cook rice, a first pattern is stored in advance in the memory means 35, which indicates how the display unit 3, bottom heating element 11, side heating element 12, and lid heating element 18 should be operated as each cooking process from the aforementioned soaking cooking to steaming progresses, thereby changing the amount of heat applied from the bottom heating element 11, side heating element 12, and lid heating element 18 to the food A in the pot 7.When the user operates the operation unit 4 to select a desired cooking course from a number of cooking courses and then issues a command to start cooking, the rice cooking control means 41 reads out the first pattern corresponding to the selected cooking course from the memory means 35, and appropriately controls the display unit 3, the bottom heating element 11, side heating element 12, and lid heating element 18, thereby performing the cooking operation for the food A in the pot 7 while displaying the first pattern on the display unit 3.

[0024] In this embodiment, it is noted that the control unit 31 is provided with a heat amount fluctuation means 44 which serves as a heat amount varying means. When the rice cooking control means 41 operates the bottom heating body 11, the side heating body 12, and the lid heating body 18 to heat the pot 7 according to a first pattern corresponding to the selected rice cooking course, the heat amount fluctuation means 44 generates a second pattern different from the first pattern as necessary, and changes the amount of heat from the bottom heating body 11, the side heating body 12, and the lid heating body 18 to the food A in the pot 7 over time based on the second pattern. The details of the heat amount fluctuation means 44 will be explained later.

[0025] The warming control means 42 controls the rice in the pot 7 to be kept at a predetermined warming temperature according to the first pattern corresponding to the selected rice cooking course described above, and is configured so that when the rice cooking control means 41 finishes cooking the rice A, regardless of the selected rice cooking course, the warming control means 42 automatically starts warming. The warming control means 42 also has a warming reheating function that controls the operation of the bottom heater 11 so that the temperature of the rice in the pot 7 is temporarily higher than the warming temperature when reheating is instructed by operating the operation unit 4 during warming. Furthermore, even if the main body 1 is in the off state immediately after commercial power is turned on and warming start is instructed by operating the operation unit 4, the warming control means 42 can keep the food A in the pot 7 warm.

[0026] Next, we will explain in detail the features of the operation of the rice cooker configured as above, especially the operation related to the heat amount fluctuation means 44. For the sake of convenience, from here on, we will use the bottom heating body 11 with a heating coil as a representative heating means, and only mention the heat amount of the bottom heating body 11.

[0027] The rice cooker of this embodiment comprises a pot 7 for containing the food A to be cooked, a bottom heating body 11 as a heating means for heating the pot 7, a rice cooking control means 41 which changes the amount of heat of the bottom heating body 11 based on a first pattern read out from the memory means 35 as each cooking step progresses, thereby cooking the food A to be cooked, and a heat amount fluctuation means 44 as a heat amount varying means which changes the amount of heat of the bottom heating body 11 over time in a second pattern different from the first pattern when the rice cooking control means 41 is controlling the operation of the bottom heating body 11 to heat the pot 7.

[0028] Figure 3 shows graphs of the pot bottom temperature Tn, which corresponds to the temperature of the bottom of the pot 7 detected by the pot temperature sensor 15, the lid temperature Tf, which corresponds to the temperature of the underside of the lid body 2 detected by the lid temperature sensor 16, and the change over time in the heat amount S of the bottom heating body 11 in the rice cooker of this embodiment.

[0029] In the figure, when rice cooking control means 41 starts cooking rice in response to an operation signal from operation unit 4, it changes the amount of heat S from the bottom heater 11 to pot 7 over time based on the first pattern, which is the standard control pattern read out from memory means 35, so that it sequentially carries out each of the following steps: "soaking cooking" to promote the absorption of water by the rice placed in pot 7, "boiling heating" to boil the water in pot 7 and then continue boiling, and "soaking" to detect that cooking is complete when the rice in pot 7 absorbs water, the water is gone, and the temperature Tn at the bottom of the pot rises above the boiling temperature (100°C), and then "soaking" to keep the inside of pot 7 at a high temperature for a predetermined period of time, such as 15 minutes. Also, after the predetermined period of "soaking" is completed, the heat retention control means 42 executes a "soaking" process to keep the cooked rice in pot 7 at a predetermined temperature, such as 73°C.

[0030] In this series of rice cooking processes, including "soaking" and "keeping warm," the rice cooking control means 41 and the keeping warm control means 42 adjust the amount of heat S of the bottom heating body 11 and the intermittent heating, which is the timing of turning on and off the electricity, to cook the food A in the pot 7. This control configuration is known and is the same as that of conventional rice cookers.

[0031] On the other hand, the heat amount fluctuation means 44, which is the main focus of the present embodiment, responds to the change in the amount of heat over time to the pot 7 by the rice cooking control means 41 according to the traditional fire control of cooking in a stove: "Trickle at first, puff up in the middle, turn off the fire when it starts to sizzle, burn a handful of straw, and don't take off the lid even if the baby cries." In response to this change, the amount of heat to the pot 7 by induction heating is increased or decreased every 100 ms (0.1 seconds) to 1 s (1 second) in a cycle of 1 to 10 seconds, and the output of the inverter 37, which corresponds to the amount of heat from the bottom heater 11, is changed to, for example, about 200 W in total to generate a second pattern. Then, a heating configuration that assumes the fluctuation of a firewood flame is added so that the amount of heat based on this second pattern is given from the bottom heater 11 to the pot 7.

[0032] That is, "Beginning is a trickle" is a gentle flame with low heat due to heating in the "soaking" process, "Chu pappa" is a strong flame with intense flame due to heating until boiling in the "heating to boiling" process, "Turn off the heat when it sizzles" is a medium flame with a gentle flame until the rice is cooked while boiling continues in the "heating to boiling" process, and "Burning a handful of straw, don't take the lid off even if the baby cries" is a low flame with a quiet flame for double cooking during the "soaking" process. In addition to the change in the amount of heat S1 to pot 7 as the process progresses by conventional rice cooking control means 41 as shown in (A) in Figure 4, a fluctuating change in the amount of heat S2 to pot 7 by heat amount fluctuating means 44 as shown in (B) in Figure 4 is added. The heat amount fluctuation means 44 sets the output maintenance time D during which the output of the inverter 37 is kept constant in a range of 0.1 to 1 second within a cycle (period) C of 1 to 10 seconds, and increases or decreases the output of the inverter 37 stepwise for each output maintenance time D, generating a second pattern in which the output change amount E, which is the difference between the upper and lower limit values ​​of the output of the inverter 37, changes to about 200 W, and applies a fluctuating change in the heat amount S2 from the bottom heating element 11 to the pot 7 in this second pattern. As a result, the final heat amount S to the pot 7 shown in Figure 3 is the heat amount S1 changed by the rice cooking control means 41 plus the heat amount S2 that fluctuates as changed by the heat amount fluctuation means 44.

[0033] In order to achieve a gentle flame at low heat during the "soaking cooking" process, the heat amount fluctuation means 44 sets the output of the inverter 37 from 500W (lower limit) → 540W → 580W → 620W → 660W → 700W (upper limit) → 660W → 620W → 580W → 540W → back to 500W (lower limit) as one cycle C, and for a gentle flame, one cycle C is set to 7 seconds. As a result, the output maintenance time D during which each output is kept constant is set to 0.7 seconds, and a cycle of change in the heat amount S2 in which the output of the inverter 37 varies every 0.7 seconds is repeatedly given from the bottom heating element 11 to the pot 7.

[0034] In addition, in order to realize high heat and intense flames when heating to boiling in the "heating to boiling" process, the heat amount fluctuation means 44 sets the output of the inverter 37 from 1200W (lower limit) → 1240W → 1280W → 1320W → 1360W → 1400W (upper limit) → 1360W → 1320W → 1280W → 1240W → back to 1200W (lower limit) as one cycle C for high heat, and sets one cycle C for intense flames as a minimum of 1 second, and sets the output maintenance time D during which each output is kept constant to a minimum of 0.1 seconds, so that a cycle of change in the heat amount S2 in which the output of the inverter 37 is varied in stages every 0.1 seconds is repeatedly given from the bottom heater 11 to the pot 7.

[0035] In addition, in order to achieve a gentle flame at medium heat while boiling continues in the "boiling heating" process until the rice is cooked, the heat amount fluctuation means 44 sets the output of the inverter 37 from 800W (lower limit) → 840W → 880W → 920W → 960W → 1000W (upper limit) → 960W → 920W → 880W → 840W → back to 800W (lower limit) as one cycle C for medium heat, and for a gentle flame, one cycle C is set to 4 seconds, and the output maintenance time D during which each output is kept constant is set to 0.4 seconds, and a cycle of change in heat amount S2 in which the output of the inverter 37 is varied in stages every 0.4 seconds is repeatedly given from the bottom heating body 11 to the pot 7.

[0036] Furthermore, in order to achieve a quiet flame on low heat during the soaking process and during double cooking during soaking, the heat amount fluctuation means 44 sets the output of the inverter 37 from 500W (lower limit) → 540W → 580W → 620W → 660W → 700W (upper limit) → 660W → 620W → 580W → 540W → back to 500W (lower limit) as one cycle C for low heat, and for a quiet flame, one cycle C is set to a maximum of 10 seconds, and the output maintenance time D during which each output is kept constant is set to a maximum of 1 second, and a cycle of change in heat amount S2 in which the output of the inverter 37 is varied in stages every second is repeatedly given from the bottom heating element 11 to the pot 7.

[0037] Note that Figure 4(B) shows the fluctuation changes of three heating amounts S2 to the pot 7 as a representative example, but the heating amount S2 and its fluctuation pattern by the heating amount fluctuation means 44 are not limited to those shown in this embodiment.

[0038] In this embodiment, while the pot 7 is being heated in the first pattern by the rice cooking control means 41, the heat amount fluctuation means 44 changes the heat amount S2 to the pot 7 over time in a second pattern different from the first pattern, making it possible to cook the food A in the pot 7 with heating similar to that of cooking in a hearth with flickering flames from a wood fire.

[0039] As shown in Figure 5, the heating amount fluctuation means 44 as a heating amount varying means is configured to vary the heating amount S of the bottom heating body 11 as a heating means in a second pattern in which the heating amount S1 according to the first pattern executed by the rice cooking control means 41 is set as a reference value S1ave, and an upper limit value S2max of the heating amount S2 larger than the reference value S1ave and a lower limit value S2min of the heating amount S2 smaller than the reference value S1ave are periodically repeated.

[0040] For example, at high heat as described above, the heating amount fluctuation means 44 changes the output of the inverter 37 from 1200W → 1240W → 1280W → 1320W → 1360W → 1400W → 1360W → 1320W → 1280W → 1240W → back to 1200W, within one cycle C, the upper limit S2max of the heating amount S2 is set to 1400W and the lower limit S2min of the heating amount S2 is set to 1200W, and the upper limit S2max and lower limit S2min of the heating amount S2 are changed periodically and repeatedly. In this case, the heating amount S2 is 1300 W on average, but by making this heating amount S2 of 1300 W correspond to the heating amount S1 by the conventional rice cooking control means 41 as the reference value S1ave, it is possible to prevent the food A in the pot 7 from being overcooked or undercooked even when taking into account the fluctuation change in the heating amount S2 by the heating amount fluctuation means 44.

[0041] Here, the heating amount fluctuation means 44 may be configured so that the output of the inverter 37 does not include the intermediate heating amount between the upper limit value S2max and the lower limit value S2min, but changes in one cycle C, for example, from 1200 W to 1400 W to 1200 W at high heat. In this case, too, the heating amount fluctuation means 44 matches the average heating amount S2 of 1300 W with the heating amount S1 by the conventional rice cooking control means 41, thereby achieving the same effect of eliminating overheating and underheating.

[0042] In this embodiment, the cooking amount fluctuation means 44 varies the heating amount S2 to the pot 7 so that the heating amount S1 according to the first pattern executed by the rice cooking control means 41 is set as an average reference value S1ave and periodically repeats between an upper limit value S2max higher than the reference value S1ave and an upper limit value S2max lower than the reference value S1ave. This makes it possible to cook the food A in the pot 7 with heating similar to that of a stove with flickering flames from a wood fire, while maintaining the average heating amount S1 of a conventional rice cooker.

[0043] In addition, the heat amount fluctuation means 44, which serves as a heat amount varying means, is configured to vary the heat amount S of the bottom surface heater 11, which serves as a heating means, so as to periodically repeat the aforementioned upper limit value S2max, lower limit value S2min, and one or more intermediate values ​​therebetween.

[0044] For example, in the above-mentioned medium heat, the heating amount fluctuation means 44 changes the output of the inverter 37 from 800W to 840W to 880W to 920W to 960W to 1000W to 960W to 920W to 880W to 840W to 800W in one cycle C, and sets the upper limit S2max of the heating amount S2 to 1000W, the lower limit S2min of the heating amount S2 to 800W, and further sets 840W, 880W, 920W, and 960W as intermediate values ​​of the heating amount S2 between them, respectively, and changes multiple intermediate values ​​in a repeated cycle in addition to the upper limit S2max and the lower limit S2min. In this case, the heating amount S2 of the bottom heater 11 may have any number of intermediate values, for example, it may be only one, 900W.

[0045] In the above example, the cycle of change in the heating amount S2 by the heating amount fluctuation means 44 is set as follows: intense flame, 1 second per cycle C; gentle flame, 7 seconds per cycle C; and quiet flame, 10 seconds per cycle C. For example, in order to achieve a medium flame and a gentle flame during the "boiling heating" process while the boiling continues, the output maintenance time D is set to 0.4 seconds in response to setting one cycle C to 4 seconds, but when the output is 1000 W, which is the upper limit value S2max of the heating amount S2, the output maintenance time D can be set to 0.1 seconds in response to setting one cycle C corresponding to an intense flame to 1 second, or when the output is 920 W, which is the intermediate value of the heating amount S2, the output maintenance time D can be set to 1 second in response to setting one cycle C corresponding to a quiet flame to 10 seconds. The output maintenance time D does not have to be constant for all outputs during one cycle, and may be changed arbitrarily for each output.

[0046] As another example, in the case of low flame described above, during one cycle C in which the heating amount fluctuation means 44 changes the output of the inverter 37 from 500W to 540W to 580W to 620W to 660W to 700W to 660W to 620W to 580W to 540W to 500W, the upper limit S2max of the heating amount S2 is set to 700W, the lower limit S2min of the heating amount S2 is set to 500W, and intermediate values ​​of the heating amount S2 between these are set to 540W, 580W, 620W, and 660W, respectively, and in addition to the upper limit S2max and the lower limit S2min, multiple intermediate values ​​are changed in a cyclical and repeated manner. In this case, the heating amount S2 of the bottom heater 11 may have any number of intermediate values, and the heating amount S2 may be increased or decreased in increments of 20 W or 50 W between 500 W and 700 W, instead of in increments of 40 W, and the value of each output may be set arbitrarily. Furthermore, here, the output change amount E, which is the difference between the upper limit value S2max (=700 W) and the lower limit value S2min (=500 W) of the heating amount S2, is set to 200 W, but it may also be 100 W or 300 W, and the value of the output change amount E may be set arbitrarily.

[0047] In this embodiment, when the heat amount fluctuation means 44 varies the heat amount S2 to the pot 7 over time in the second pattern, in addition to the upper limit S2max and lower limit S2min of the heat amount S2, one or more intermediate heat amount S2 values ​​are added, making it possible to cook the food A in the pot 7 with heating that is closer to the style of cooking in a stove with flickering flames from a wood fire.

[0048] In this embodiment, the heat amount fluctuation means 44 is configured to vary the heat amount S2 of the bottom heater 11 over time by varying the upper limit value S2max, the lower limit value S2min, and one or more intermediate values ​​of the heat amount S2 in an irregular pattern, or by mixing an irregular pattern with a regular pattern.

[0049] "Fluctuation" is an unpredictable spatial or temporal change or movement, and "unpredictable" means that there is no regularity. In other words, "fluctuation" refers to irregular spatial or temporal changes or movements. For example, not only the movement of the wind or the flow of a river, but also the flames of a wood fire are included in the "fluctuation" which is an irregular pattern. It is well known that even things that appear constant are not stable and cannot be predicted.

[0050] In addition, fluctuations in which irregular patterns are mixed within regular patterns are called "1 / f fluctuations." The degree of fluctuation is expressed by the frequency "f," and the types of fluctuations are "1 / √f," "1 / f," and "1 / f 2 ", "1 / f 3 It is also well known that it can be expressed as "."

[0051] In the above example, the heating amount fluctuation means 44 has been described as periodically repeating the change over time in the heating amount S2 equivalent to a preset fluctuation for each cycle C. However, the fluctuation pattern may also be changed irregularly by changing the fluctuation pattern corresponding to a second pattern consisting of each value of the heating amount S2 (upper limit value S2max, upper limit value S2max, intermediate value) and time elements (cycle C, output maintenance time D) from a predetermined setting, triggered by a change in the cooking state that changes as the pot 7 is heated, in accordance with the temperature detected by the pot temperature sensor 15, the temperature detected by the lid temperature sensor 16, or the pressure detected by the pressure sensor 17.

[0052] A specific example will be described below with reference to Fig. 6 to Fig. 8. Fig. 6 is a graph showing the change in temperature over time of each part until the inside of pot 7 boils in the boiling heating process in the rice cooker of this embodiment. In the figure, Tn indicates the change in the pot bottom temperature, which is the temperature detected by pot temperature sensor 15, Ts indicates the temperature change of the inside of pot 7, Tf(A) indicates the change in the lid temperature, which is the temperature detected by lid temperature sensor 16 under normal conditions, Tf(B) indicates the change in the lid temperature when the temperature rise of the upper part of pot 7 is faster than that of the lower part, Tf(C) indicates the change in the lid temperature when the temperature rise of the upper part of pot 7 is slower than that of the lower part, (d) indicates the boiling detection due to the change in the temperature rise rate of the lid temperature Tf, (e) indicates the boiling detection due to the change in the temperature rise rate of the pot bottom temperature Tn, and (H) indicates the heating adjustment until boiling.

[0053] When the boiling heating process is started under the control of the rice cooking control means 41 and the pot 7 is strongly heated with the heat amount S of the bottom heater 11 that realizes the intense flame at the strong heat described above, the pot bottom temperature Tn measured by the pot temperature sensor 15 and the lid temperature Tf measured by the lid temperature sensor 16 gradually rise. If the temperature rise rate (g) of the lid temperature Tf is smaller than the predetermined temperature rise rate (f) from immediately after the start of the boiling heating process until the pot bottom temperature Tn reaches the predetermined temperature of 80°C, it is understood that the temperature rise in the upper part of the pot 7 is slow. This can be caused by a weak heating amount, a large amount of water for the food A to be cooked, or a cold water temperature, and in such cases, in traditional cooking stoves, the firewood fire is strengthened and the heat is adjusted based on experience.

[0054] Therefore, in this embodiment, in order to achieve the same heat control as cooking in a stove, if the temperature rise rate (g) of the lid temperature Tf is smaller than a predetermined value relative to the temperature rise rate (f) when the pot bottom temperature Tn reaches a predetermined temperature immediately after the start of the boiling heating process, the heat amount fluctuation means 44 is configured so that the fluctuation pattern of the heat amount S2 to the pot 7, which is set as the second pattern, temporarily changes during the subsequent period of heating adjustment (H) until boiling, by increasing the heat amount S2.

[0055] In other words, in the above example, in order to realize a strong and intense flame when heating to boiling in the "heating to boiling" process, heating amount fluctuation means 44 set the lower limit S2min at 1200W and the upper limit S2max at 1400W and periodically changed the heating amount S2 in a cycle C of 1 second, but in this case, the lower limit S2min is increased from 1200W to 1300W and the output maintenance time D during which the heating amount S2 is maintained at the upper limit S2max of 1400W is lengthened from 100ms (0.1 seconds) to 500ms (0.5 seconds), thereby temporarily increasing the heating amount S2 of pot 7.

[0056] Next, an example of adjusting the heating amount S2 during the "heating to boil" process while boiling continues after boiling will be described with reference to Figures 7 and 8. In each of these figures, heating amount fluctuation means 44 is configured to monitor the temperature state of the upper part of pot 7 based on the change in lid temperature Tf measured by lid temperature sensor 16 when the rate of temperature rise (e) of pot bottom temperature Tn measured by pot temperature sensor 15 falls below a predetermined value during the period up to boiling and boiling is detected (X), and to adjust the heating amount S2 according to the fluctuation pattern after boiling is detected depending on the monitoring results.

[0057] 7, lid temperature Tf, which is the temperature detected by lid temperature sensor 16, rises rapidly when the upper part of pot 7 begins to boil. The phenomenon in which lid temperature Tf rises to a predetermined value or more within a predetermined time is monitored by heat amount fluctuation means 44 using the temperature rise rate (i) of lid temperature Tf.

[0058] Here, heat amount fluctuation means 44 uses the time (X) when pot bottom temperature Tn measured by pot temperature sensor 15 falls below a predetermined value for a predetermined time, i.e., the temperature rise rate (e) of pot bottom temperature Tn falls below a predetermined value and boiling is detected, as a reference and determines how much time difference there is between that time and the time when the temperature rise rate (i) of lid temperature Tf rises to a predetermined value. If the temperature rise rate (i) of lid temperature Tf reaches or exceeds the predetermined value earlier than the time (X) when boiling is detected at pot bottom temperature Tn, it is possible that the amount of heat is too strong, or the amount of water for food A to be cooked is too small, or the water temperature is too high, and so heat amount fluctuation means 44 reduces the heat amount S2 of pot 7 while boiling continues. Conversely, if the point at which the temperature rise rate (i) of the lid temperature Tf reaches or exceeds the specified value is later than the point at which boiling is detected at the pot bottom temperature Tn (X), then it is possible that the amount of heating was too weak, the amount of water was too much, or the water temperature was too low, and so the heating amount fluctuation means 44 increases the heating amount S2 of the pot 7 while boiling continues.

[0059] 8, heat amount fluctuation means 44 uses the time (X) when boiling is detected at the aforementioned pot bottom temperature Tn as a reference and determines the time difference from that point in time when the lid temperature Tf falls below a predetermined value within a predetermined time, i.e., the rate of temperature rise (d) of the lid temperature Tf falls below a predetermined value and boiling is detected by lid temperature sensor 16. If the time when the rate of temperature rise (d) of the lid temperature Tf falls below the predetermined value is delayed within the predetermined time from the time (X) when boiling is detected at the pot bottom temperature Tn, this may be because the amount of heating was too strong, the amount of water was too little, or the water temperature was too high, so heat amount fluctuation means 44 reduces the amount of heating S2 of pot 7 while boiling continues. Conversely, if the point at which the temperature rise rate (d) of the lid temperature Tf falls below a specified value is delayed by more than a specified time from the point at which boiling is detected at the pot bottom temperature Tn (X), then it is possible that the amount of heating was too weak, the amount of water was too much, or the water temperature was low, and so the heating amount fluctuation means 44 increases the heating amount S2 of the pot 7 while boiling continues.

[0060] That is, in the above example, the heating amount fluctuation means 44 periodically and repeatedly changes the heating amount S2 in a cycle C of 4 seconds with the lower limit S2min set to 800 W and the upper limit S2max set to 1000 W in order to realize a medium-heat, gentle flame until the rice is cooked while the boiling continues in the "boiling heating" process, but when increasing the heating amount S2 due to the fluctuation pattern after boiling detection, the lower limit S2min is increased from 800 W to 900 W, or the output maintenance time D during which the heating amount S2 is maintained at the upper limit S2max of 1000 W is made longer than the predetermined time of 400 ms (0.4 seconds). Conversely, when decreasing the heating amount S2 due to the fluctuation pattern after boiling detection, the upper limit S2max is decreased from 100 W to 900 W, or the output maintenance time D during which the heating amount S2 is maintained at 900 W is made shorter than the predetermined time of 400 ms (0.4 seconds).

[0061] In this embodiment, the heat amount fluctuation means 44 is configured to temporarily generate an irregular pattern or a regular pattern mixed with an irregular pattern for the amount of heat S2 from the bottom heater 11 to the pot 7, particularly during heating up to boiling or heating while boiling continues, based on the relationship between the temperature changes detected by the pot temperature sensor 15 and the lid temperature sensor 16. However, the heat amount fluctuation means 44 may temporarily generate an irregular pattern or a regular pattern mixed with an irregular pattern for the fluctuation in the amount of heat S2 during other rice cooking processes, for example, during cooking or steaming. Also, the trigger for generating a pattern including such irregularities is not limited to the relationship between the temperature changes detected by the pot temperature sensor 15 and the lid temperature sensor 16, and may take into account the relationship between the pressure changes detected by the pressure sensor 17, etc.

[0062] That is, in traditional cooking with a stove, the heat of the firewood is adjusted using the five human senses as sensors, such as the state of the firewood, steam, the time when the boiling sound occurs, the strength of the steam generation, the time when the steam is generated, and the smell, but the heat is not the same every time, but is flexibly changed according to the state of steam generation, etc. In this way, the rice cooker of this embodiment also has the purpose of adjusting the next heating amount S2 according to the progress of cooking, such as the temperature and pressure during cooking and the generation of steam.

[0063] Therefore, when pressurizing the pot 7 during boiling, based on the rate of pressure increase in the pot 7 detected by the pressure sensor 17 and the rate of pressure reduction (rate of pressure decrease) in the pot 7 when the pressure is released, when the pot 7 reaches a boiling state, the subsequent fluctuations in the heating amount S2 may be temporarily changed to a pattern that includes irregularities.

[0064] In this embodiment, the heat amount fluctuating means 44 can be used to make the heat amount S2 of the bottom heating element 11 have an irregular pattern, or a pattern that is a mixture of a regular pattern and an irregular pattern, thereby making it possible to cook the food A in the pot 7 with heating that is closer to the style of cooking in a hearth, where the flames of a wood fire flicker.

[0065] In addition, the control unit 31, which is equipped with an AI (artificial intelligence) function, can learn how to adjust the next heating depending on the progress of the cooking process, such as the temperature and pressure during cooking and steam generation, from actual data on the temperature and pressure of cooking in a stove, thereby making the AI's instructions irregular.

[0066] The heating amount fluctuation means 44 of this embodiment is configured to periodically repeat the upper limit value S2max of the heating amount S2 and the lower limit value S2min of the heating amount S2, and change the heating amount S2 of the bottom heating element 11 so that the upper limit value S2max and the lower limit value S2min associated with the time element of the heating amount S2, i.e., the upper limit value S2max, the lower limit value S2min, and / or the cycle C, which is the period, change according to the progress of the rice cooking process.

[0067] This means that in response to the time-dependent changes in heating of pot 7 caused by rice cooking control means 41, which is in line with the traditional fire control for cooking rice in a stove mentioned above, "Trickle at first, pop in the middle, turn down the heat when it starts to sizzle, burn a handful of straw, and don't take off the lid even if the baby cries," a second pattern is generated in which the amount of heat S2 to pot 7 by induction heating is increased or decreased every 0.1 to 1 second within a cycle of 1 to 10 seconds as each stage of cooking progresses, and the output of inverter 37, which corresponds to the amount of heat of bottom heater 11, is changed to about 200 W in total, and a heating configuration is added in heat amount fluctuation means 44 that assumes the fluctuation of a wood-fired flame so that the amount of heat S2 based on this second pattern is given to pot 7.

[0068] In the above example, the upper limit S2max and lower limit S2min of the strength waveform associated with the time element of the heat amount S2 are changed according to the change over time in the rice cooking process. That is, in the heating of the soaking process corresponding to "First trickle", the inverter 37 output is set to low heat of 500W to 700W, and a gentle flame heat amount S2 of one cycle C for 7 seconds is applied to the pot 7, and in the heating to boiling process corresponding to "Medium puff", the inverter 37 output is set to high heat of 1200W to 1400W, and an intense flame heat amount S2 of one cycle C for 1 second ...id-puff", the inverter 37 output is set to high heat of 1200W to 1400W, and an intense flame heat amount S2 of one cycle C for 1 second is applied to the pot 7. In the heating while boiling continues in the boiling heating process corresponding to "burning a handful of straw and not taking the lid off even if the baby cries," the output of the inverter 37 is set to medium heat of 800 W to 1000 W, and a gentle flame heating amount S2 of one cycle C for 4 seconds is given to the pot 7. In the heating for double cooking during steaming in the steaming process corresponding to "burning a handful of straw and not taking the lid off even if the baby cries," the output of the inverter 37 is set to low heat of 500 W to 700 W, and a gentle flame heating amount S2 of one cycle C for 10 seconds is given to the pot 7.

[0069] In this embodiment, the heat amount fluctuation means 44 changes the upper limit S2max and lower limit S2min associated with the time element of the heat amount S2 in accordance with changes over time in the cooking process, making it possible to cook the food A in the pot 7 with heating that differs for each cooking stage and is similar to the style of cooking in a hearth with flickering flames from a wood fire.

[0070] The heat amount fluctuation means 44 of this embodiment has a configuration for setting an upper limit value S2max of the heat amount S2, a lower limit value S2min of the heat amount S2, and one or more intermediate values ​​of the heat amount S2 from a plurality of stepwise heat amounts S2.

[0071] 9 shows the relationship between the heating amount S2 and time at high heat with the inverter 37 output in the range of 1200W to 1400W in the above example. As shown in FIG. 9(B), the heating amount fluctuation means 44 sets the heating amount S2 corresponding to high heat from six heating amount S2 stages consisting of 1200W, 1240W, 1280W, 1320W, 1360W, and 1400W, and configures the fluctuation of the heating amount S2 by the length of the heating amount S2 at each stage, that is, the length of the output maintenance time D. For comparison, FIG. 9(A) shows an example in which the heating amount S2 is continuously and steplessly varied by the heating amount fluctuation means 44.

[0072] Fig. 10 shows the relationship between the heating amount S2 and time at medium heat with the inverter 37 output in the range of 800W to 1000W in the above example. As shown in Fig. 10(B), the heating amount fluctuation means 44 sets the heating amount S2 corresponding to medium heat from six heating amount S2 stages consisting of 800W, 840W, 880W, 920W, 960W, and 1000W, and configures the fluctuation of the heating amount S2 by the length of the output maintenance time D at each stage. For comparison, Fig. 10(A) shows an example in which the heating amount S2 is continuously and steplessly varied by the heating amount fluctuation means 44.

[0073] Fig. 11 shows the relationship between the heating amount S2 and time at low heat with the inverter 37 output in the range of 500W to 700W in the above example. As shown in Fig. 11(B), the heating amount fluctuation means 44 sets the heating amount S2 corresponding to low heat from six levels of heating amount S2 consisting of 500W, 540W, 580W, 620W, 660W, and 700W, and configures the fluctuation of the heating amount S2 by the length of the output maintenance time D at each level. For comparison, Fig. 11(A) shows an example in which the heating amount S2 is continuously and steplessly varied by the heating amount fluctuation means 44.

[0074] In this embodiment, the heating amount fluctuation means 44 is configured to set the heating amount band (range of heating amount S2) constituting the main parts of high heat, medium heat, and low heat, for example, by multiple stages of heating amounts including an upper limit value S2max, a lower limit value S2min, and an intermediate value. Therefore, it is not necessary to continuously vary the high-frequency pulse drive signal to the inverter 37, and the circuit configuration of the first heating drive unit 32 including the inverter 37 can be simplified, and the inverter 37 can be made smaller.

[0075] The heating amount fluctuation means 44 of the present embodiment has a configuration for setting the upper limit S2max of the heating amount S2 so that it does not exceed the rated power consumption of the rice cooker.

[0076] The indication of the rated power consumption of a rice cooker is determined by the Electrical Appliance and Material Safety Law. In the above example, even if the output of the inverter 37 is set to 1200W to 1400W on high heat, the power consumption fluctuates over time, making it difficult to inspect the power consumption on a manufacturing assembly line, etc. Therefore, in this embodiment, the control unit 31 including the rice cooking control means 41 and the heating amount fluctuation means 44 controls and limits the output of the inverter 37 corresponding to the upper limit value S2max of the heating amount S2 so that it does not exceed the rated power consumption of the rice cooker, or if it exceeds, it is within 5%, specifically, when the rated power consumption of the rice cooker is 1400W, the output of the inverter 37 is 1470W or less. In addition, the control unit 31 of the rice cooker may be added with a configuration of an inspection means (not shown) that operates the inverter 37 at an output of 1400W for, for example, 60 seconds or outputs the inverter 37 continuously for a predetermined time as a test mode for inspection.

[0077] However, the rated power consumption of the rice cooker may include not only the heating from the bottom heating element 11 to the pot 7 by the heating coil, but also the heating of the lid 2 by the lid heating element 18 and the heating of the side of the pot 7 by the side heating element 12. Therefore, for example, if the power consumption of the lid heating element 18 is 50 W and heating is performed simultaneously with the bottom heating element 11, it is preferable to set the output of the inverter 37, which corresponds to the upper limit S2max of the heating amount S2, to 1,350 W, which is the total power consumption of the bottom heating element 11 and the lid heating element 18 and does not exceed the rated power consumption of the rice cooker.

[0078] In the above example, the output of the inverter 37 is set to a high flame in the range of 1200W to 1400W, and the lower limit S2min of the heating amount S2 is set to 1200W, but in the case of an actual wood fire, the heating power corresponding to the heating amount S2 to the pot 7 does not drop significantly instantaneously even if there is a fluctuation, so it is preferable that the heating amount fluctuation means 44 sets a limit on the lower limit S2min so that the lower limit S2min of the heating amount S2 does not fall below 50% of the upper limit S2max. That is, if the upper limit S2max of the heating amount S2 is set to 1400W, the lower limit S2min of the heating amount S2 is limited not to fall below 700W.

[0079] In this embodiment, when fluctuation control is added to the heat amount S2 of the bottom heating body 11 by the heat amount fluctuation means 44, there is no problem with power consumption inspection during manufacture, and in compliance with laws and regulations, problems such as a current flowing that exceeds the rated power consumption of the rice cooker and exceeds the limited current of the indoor wiring can be prevented.

[0080] The heat amount fluctuation means 44 of the present embodiment is configured to have a plurality of second patterns according to the type of rice cooking performed by the rice cooking control means 41.

[0081] A method of cooking rice in which the rice cooking control means 41 detects the amount of food A (amount of cooked rice) placed in the pot 7 and changes the heating pattern, which is a first pattern, depending on the amount of cooked rice, a method of cooking rice in which brown rice, polished rice, local variety brand rice, etc. are selected by operation from the operation unit 4 and a heating pattern according to the rice quality is used, and a method of cooking rice in which the cooked texture, such as hard, soft, sticky, sweet, etc., is changed by operation from the operation unit 4 and a heating pattern according to the selected texture is used. In this embodiment, a specific second pattern that enables the heating amount fluctuation means 44 to control the fluctuation of the heating amount S2 in the various conventional cooking methods performed by the rice cooking control means 41 can be selected from a plurality of second patterns stored in advance in the storage means 35 and applied.

[0082] In this manner, in this embodiment, the second pattern that enables appropriate fluctuation control of the heating amount S can be selected according to the amount of cooked rice, the cooking menu, the cooking method, and the rice producing region, variety, and brand.

[0083] The present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, the "predetermined value," "predetermined temperature," and "predetermined rate of temperature increase" that appear frequently in the present embodiment do not need to be the same value each time, and may be set to a different value. [Explanation of symbols]

[0084] 7. Hotpot 11 Bottom heating element (heating means) 41 Rice cooking control means 44 Heat amount fluctuation means (heat amount variable means) C Cycle (length of period) D Output maintenance time (maintenance time for heating amount 1)

Claims

1. A pot for containing food to be cooked; A heating means for heating the pan; A rice cooking control means for changing the amount of heat of the heating means as the process progresses to cook the food to be cooked; A heating amount varying means for varying the heating amount of the heating means over time; Equipped with The steps include a soaking step, a heating step until boiling, a heating step while boiling continues, and a steaming step, the heating amount varying means varies the heating amount of the heating means so as to periodically repeat an upper limit value of the heating amount, a lower limit value of the heating amount, and one or more heating amount values ​​between the upper limit value and the lower limit value in at least two or more steps of the soaking cooking step, the heating step until boiling, the heating step while boiling continues, and the steaming step, the upper limit value, the lower limit value, and the length of the cycle are different; A rice cooker characterized in that the maintenance time of one heating amount in the cycle varies depending on the length of the cycle.

2. The upper limit value and the lower limit value are The heating step until boiling>the heating step during boiling>the soaking and cooking step, The heating step until boiling>the heating step during boiling>the steaming step 2. The rice cooker according to claim 1,

3. The length of the repeating period is The heating step until boiling is less than the soaking step is less than the steaming step, and 3. The rice cooker according to claim 1, wherein the heating step until boiling is smaller than the heating step during boiling is smaller than the steaming step.

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