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 over a firewood flame in a hearth, the flame fluctuates, subtly changing the heat intensity and heating the bottom and sides of the pot containing the food to be cooked.

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

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

[0005] The conventional technology described above promotes water convection within the pot during cooking, heating the rice in the pot with an even distribution of water, thereby gelatinizing the rice evenly throughout the pot. This technology is thought to focus on the important points for beautifully cooking rice seen in traditional kamado cooking. However, in kamado cooking, the wood fire that serves as the heat source is located away from the pot, and indirect heating occurs with an air layer in between, causing the amount of heat reaching 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 method itself is different.

[0006] In addition to induction rice cookers, 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 rice cookers that cook rice by placing water between the pot and the outer pot, but none of these have been able to produce a fluctuating amount of heat in the pot like a kamado rice cooker.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a rice cooker that can cook rice with heating similar to that of a traditional Japanese 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, wherein the processes include a soaking process, a heating process until boiling, a heating process while boiling continues, and a steaming process, and the heat amount varying means varies the amount of heat of the heating means so as to periodically 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 of the soaking process, the heating process until boiling, the heating process while boiling continues, and the steaming process, wherein the upper limit value, the lower limit value, and the length of the cycle are different, and the maintenance time of one heat amount in the cycle varies depending on the length of the cycle. [Effects 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 explanation of the drawings]

[0010] [Figure 1] 1 is a schematic explanatory diagram of a rice cooker showing one embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing the electrical configuration of the rice cooker. [Figure 3] 10 is a graph showing the change over time in the 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 show (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. [Figure 5] 10 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] 10 is a graph showing the change in temperature of each part over time during the boiling heating process. [Figure 7]10 is a graph showing the change in temperature of each part over time during the boiling heating process. [Figure 8] 10 is a graph showing the change in temperature of each part over time during the boiling heating process. [Figure 9] 10 is a graph showing the relationship between the amount of heat and time when heated over high heat. [Figure 10] 10 is a graph showing the relationship between the amount of heat and time at medium heat. [Figure 11] 10 is a graph showing the relationship between the amount of heat and time on low heat. DETAILED DESCRIPTION OF THE INVENTION

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

[0012] First, the overall configuration of the rice cooker of this embodiment will be described with reference to Figure 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 main body 1, with main body 1 and lid 2 forming the exterior of the rice cooker. On the front of main body 1 is disposed a display / operation unit 5 that collectively arranges a display unit 3 such as an LED or LCD display (to be described later) and an operation unit 4 such as operation keys or a touch panel. Display / operation unit 5 may be disposed on lid 2 instead of main body 1.

[0013] A tubular pot 7 with a bottom that contains rice and water as food to be cooked A is detachably mounted inside the main body 1. When the lid 2 is opened, the pot 7 can be taken out and put in through the opening at 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 closes the top of the opening of the pot 7, forming an inner-pot space 9 inside the main body 1 and the pot 7, surrounded by the inside surface of the pot 7, the top surface of the food to be cooked A, and the underside of the inner lid 8. Although not shown, the pot 7 is primarily 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, there are arranged a bottom heating element 11 using a heating coil and a side heating element 12 using a cord heater, which serve as heating means for heating the pot 7 in order to cook the food A to be cooked. Bottom heating element 11, which serves as the main heating means for the pot 7, is positioned facing the bottom of the pot 7 from the lower side where the heating element is located. As a result, when bottom heating element 11 is energized, the alternating magnetic field from bottom heating element 11 causes the heating element of the pot 7 to heat, raising the temperature of the pot 7 and heating the food A to be cooked. Side heating element 12, which serves as auxiliary heating means for the pot 7, is positioned facing the upper side of the pot 7, and when side heating element 12 is energized, radiant heat from side heating element 12 heats mainly the upper side of the pot 7. Side heater 12 may be configured with a heating coil, similar to bottom heater 11, and the upper side of pot 7 may be heated by electromagnetic induction in addition to the lower side and bottom portions of pot 7. Pot 7 may also be heated by a heating method other than electromagnetic induction.

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

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

[0017] The lid 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, by extension, the space inside the pot 9, a pressure sensor 17 that detects the internal pressure of the pot 7, and a lid heater 18 such as a cord heater. The lid temperature sensor 16 and lid heater 18 mainly control the temperature of the inner lid 8 using the lid heating means 23, and when the inner lid 8 is attached to the lid 2, the lid temperature sensor 16 comes into contact with the top surface of the inner lid 8, and the lid heater 18 is positioned opposite the top surface of the inner lid 8. The lid heater 18 may be composed of a heating coil and the inner lid 8 may be composed of a magnetic material, allowing the inner lid 8 to be heated by electromagnetic induction.

[0018] A pressure regulating valve 20 including a ball-shaped valve element 19 is disposed approximately in the center of inner lid 8, which forms the underside of lid 2. Pressure regulating valve 20 is disposed midway through the steam passage space that connects pot interior space 9 with lid 2 and ultimately the outside of the rice cooker (outside the machine). A movable mechanism (not shown), such as a solenoid, is provided inside lid 2 to move valve element 19 forward or backward toward or away from pressure regulating valve 20. When valve element 19 advances into pressure regulating valve 20 and blocks the steam passage space, pot interior space 9 can be pressurized above atmospheric pressure until the pressure in pot interior space 9 increases as pot 7 is heated and pushes up the valve element. When valve element 19 retracts from pressure regulating valve 20 to open the steam passage space, pot interior space 9 can be maintained at atmospheric pressure regardless of how much heat is applied to pot 7. Pressure sensor 17 is provided inside lid 2 facing pressure regulating valve 20, but it may be provided in another location as long as it can detect the pressure in pot interior space 9.

[0019] Figure 2 shows the electrical configuration of the rice cooker of this embodiment. In the figure, reference numeral 31 denotes a control unit incorporated inside the main body 1 or lid 2, and comprising a microcomputer and drive elements for each component. The input port of the control unit 31 is electrically connected to the operation unit 4, pan temperature sensor 15, lid temperature sensor 16, and pressure sensor 17. The output port of the control unit 31 is electrically connected to the display unit 3, a first heating drive unit 32 connected to the bottom heater 11, a second heating drive unit 33 connected to the side heater 12, and a third heating drive unit 34 connected to the lid heater 18. The control unit 31 incorporates storage means 35, such as a readable and writable memory, for storing various information and data.

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

[0021] The first heating drive unit 32 mainly comprises a power supply circuit 36, an inverter 37, and an IH drive circuit 38. The power supply circuit 36 ​​corresponds to a rectifying and smoothing circuit that converts the commercial power supply voltage, for example, 100 V AC, supplied to the main body 1 into DC voltage, and the DC voltage from the power supply circuit 36 ​​is applied as input voltage to the inverter 37. Although neither is shown, the inverter 37 is a well-known voltage-type resonant inverter that includes a resonant capacitor 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 connected in series with the resonant circuit. The IH drive circuit 38 receives a first heating control signal from the control unit 31 and sends a pulse drive signal to the gate of the switching element, sufficient to turn the switching element of the inverter 37 on and off. As a result, when a pulse drive signal is sent 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, causing the power supply voltage from power supply circuit 36 ​​to be intermittently applied to the resonant circuit of inverter 37, and high-frequency current to be supplied to bottom heater 11. By changing the period of the pulse drive signal and the ratio of on time to one period (on time ratio), it is possible to increase or decrease the output power (output) from inverter 37, and therefore the amount of heat from bottom heater 11 to pot 7.

[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 the power supply circuit 36 ​​to the cord heater that serves as the side heating element 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 the power supply circuit 36 ​​to the cord heater that serves as the lid heating element 18. The control unit 31 also has the function of sending a separate control signal to, for example, a drive unit for a solenoid that operates the valve element 19 to turn the solenoid on and off; however, this is not particularly relevant to this embodiment and will not be described or illustrated further.

[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 the steps of soaking, which promotes the absorption of water by the rice in the food A placed in the pot 7; boiling, which brings the temperature of the food A to a boil in a short time and then keeps the food A boiling until it is in a dry-up state with no water; and steaming, which maintains the temperature of the food A in a dry-up state at a high enough temperature to prevent it from burning, 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 shows how the display unit 3, bottom heating element 11, side heating element 12, and lid heating element 18 should be operated as each cooking step from the aforementioned soaking cooking to steaming should progress, thereby changing the amount of heat applied to the food A in the pot 7 from the bottom heating element 11, side heating element 12, and lid heating element 18.After the user operates the operation unit 4 to select the desired cooking course from multiple 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 by appropriately controlling the display unit 3, the bottom heating element 11, side heating element 12, and lid heating element 18, the rice is cooked for the food A placed in the pot 7, while the display unit 3 displays the first pattern.

[0024] It is noteworthy that in this embodiment, the control unit 31 is equipped 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 element 11, side heating element 12, and lid heating element 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 varies the amount of heat provided to the food A in the pot 7 from the bottom heating element 11, side heating element 12, and lid heating element 18 over time based on this second pattern. The heat amount fluctuation means 44 will be explained in more detail later.

[0025] The keep-warm control means 42 controls the rice in the pot 7 to keep it at a predetermined keep-warm temperature according to the first pattern corresponding to the selected cooking course, and is configured so that when the rice cooking control means 41 finishes cooking the rice A, the keep-warm control means 42 automatically starts keeping it warm, regardless of the selected cooking course. The keep-warm control means 42 also has a keep-warm reheating function that controls the operation of the bottom heater 11 so that the temperature of the rice in the pot 7 temporarily rises above the keep-warm temperature when a command to reheat is issued via the operation unit 4 during keep-warm operation. Furthermore, even when the main unit 1 is in the off state immediately after commercial power is turned on and a command to start keep-warm is issued via the operation unit 4, the keep-warm control means 42 can keep the rice A placed in the pot 7 warm.

[0026] Next, we will explain in detail the operational characteristics of the rice cooker configured as above, particularly those related to the heat amount fluctuation means 44. For the sake of convenience, from here on, we will use the bottom heating element 11, which is a heating coil, as a representative heating element, and only refer to the heat amount of the bottom heating element 11.

[0027] The rice cooker of this embodiment comprises a pot 7 that contains the food A to be cooked, a bottom heating element 11 as a heating means for heating the pot 7, a rice cooking control means 41 that changes the amount of heat from the bottom heating element 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 that changes the amount of heat from the bottom heating element 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 element 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 receives an operation signal from operation unit 4 and starts cooking rice, it changes the amount of heat S from 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 performs each of the following processes in order: "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 the rice is cooked when the rice in pot 7 has absorbed the water, the water is gone, and the temperature at the bottom of the pot Tn exceeds the boiling temperature (100°C), and then maintains the temperature inside pot 7 at a high temperature for a predetermined period of time, such as 15 minutes.

[0030] In this series of rice cooking processes, from "soaking" to "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 element 11 and the timing of power on / off, and the control configuration for cooking the food A in the pot 7 is the same as that of conventional rice cookers and is known.

[0031] Meanwhile, the heat amount fluctuation means 44, which is the focus of the present invention, responds to the change in the amount of heat supplied to the pot 7 over time by the rice cooking control means 41, which follows the traditional cooking method of "start by trickling, then by blowing, then when it starts to sizzle, turn off the heat, burn a handful of straw, and don't take off the lid even if the baby cries" by increasing or decreasing the amount of heat supplied to the pot 7 by induction heating every 100 ms (0.1 seconds) to 1 s (1 second) in a cycle of 1 to 10 seconds, thereby generating a second pattern in which the output of the inverter 37, which corresponds to the amount of heat supplied to the bottom heater 11, changes to, for example, about 200 W overall. Then, a heating configuration that takes into account the fluctuations of a firewood flame is added so that the amount of heat supplied to the pot 7 from the bottom heater 11 based on this second pattern is supplied based on this second pattern.

[0032] That is, "First trickle" is a gentle flame over low heat during heating in the "soaking" process; "Chu pappa" is a strong flame over high heat during heating until boiling in the "heating to a boil" process; "Turn off the heat when it starts to sizzle" is a gentle flame over medium heat during boiling in the "heating to a boil" process until the rice is cooked through; and "Burn a handful of straw, don't take the lid off even if the baby cries" is a gentle flame over low heat during double cooking during the "soaking" process, and a fluctuating change in the amount of heat S2 to the pot 7 by the heat amount fluctuating means 44 as shown in FIG. 4(B) is added to the change in the amount of heat S1 to the pot 7 as the process progresses by the conventional rice cooking control means 41 as shown in FIG. 4(A). Heat amount fluctuation means 44 sets the output maintenance time D, during which the output of inverter 37 is kept constant, in the range of 0.1 to 1 second within a cycle (period) C of 1 to 10 seconds, and increases or decreases the output of inverter 37 in stages 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 inverter 37, changes to about 200 W. This second pattern imparts a fluctuating change in heat amount S2 from bottom heating element 11 to pot 7. As a result, the final heat amount S to pot 7 shown in Figure 3 is the heat amount S1 changed by rice cooking control means 41 plus the heat amount S2 fluctuatingly changed by heat amount fluctuation means 44.

[0033] In order to achieve a gentle flame at low heat during the "soaking" process, the heat amount fluctuation means 44 is configured so that for low heat, one cycle C is the output of the inverter 37 returning from 500W (lower limit) → 540W → 580W → 620W → 660W → 700W (upper limit) → 660W → 620W → 580W → 540W → 500W (lower limit), and for a gentle flame, one cycle C is set to 7 seconds, and the output maintenance time D during which each output is kept constant is set to 0.7 seconds, and a cycle of change in 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 achieve high heat and an intense flame when heating to boiling in the "heating to boiling" process, the heat amount fluctuation means 44 is configured so that for high heat, the output of the inverter 37 is changed from 1200W (lower limit) → 1240W → 1280W → 1320W → 1360W → 1400W (upper limit) → 1360W → 1320W → 1280W → 1240W → back to 1200W (lower limit), which is one cycle C, and for intense flame, one cycle C is set to a minimum of 1 second, and the output maintenance time D during which each output is kept constant is set to a minimum of 0.1 seconds, and a cycle of change in heat amount S2 in which the output of the inverter 37 is varied in stages every 0.1 seconds is repeatedly applied from the bottom heating element 11 to the pot 7.

[0035] In addition, in order to achieve a gentle flame at medium heat while the boiling continues in the "boiling heating" process until the rice is cooked, the heat amount fluctuation means 44 is configured so that for medium heat, the output of the inverter 37 is changed from 800W (lower limit) → 840W → 880W → 920W → 960W → 1000W (upper limit) → 960W → 920W → 880W → 840W → back to 800W (lower limit), with one cycle C, 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 element 11 to the pot 7.

[0036] Furthermore, in order to achieve a quiet flame on low heat during the soaking process and the double cooking during soaking, the heat amount fluctuation means 44 is configured so that for low heat, one cycle C is the output of the inverter 37 changing from 500W (lower limit) → 540W → 580W → 620W → 660W → 700W (upper limit) → 660W → 620W → 580W → 540W → back to 500W (lower limit), 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 is repeatedly given from the bottom heating element 11 to the pot 7, so that the output of the inverter 37 changes in stages every second.

[0037] Note that Figure 4(B) shows the fluctuations 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 rice cooking control means 41 heats the pot 7 in the first pattern, 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 in a heating manner similar to cooking in a stove 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 element 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 the heating amount S of the bottom heating element 11 as a heating means is varied in a second pattern in which an upper limit value S2max of the heating amount S2 greater 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, in one cycle C, the upper limit value S2max of the heating amount S2 is set to 1400W and the lower limit value S2min of the heating amount S2 is set to 1200W, and the upper limit value S2max and lower limit value S2min of the heating amount S2 are changed periodically and repeatedly. In this case, the average heating amount S2 is 1300 W, but by making this 1300 W heating amount S2 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 to be cooked in the pot 7 from being overcooked or undercooked even when taking into account fluctuations 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 instead changes in one cycle C, for example, from 1200 W to 1400 W and back to 1200 W on 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 to be cooked in the pot 7 with heating similar to that of a stove, where the flames flicker over a wood fire, while maintaining the average heating amount S1 of a conventional rice cooker.

[0043] In addition, the heat quantity fluctuation means 44, which serves as a heat quantity varying means, is configured to vary the heat quantity S of the bottom surface heating body 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 setting, 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. The upper limit S2max of the heating amount S2 is set to 1000W, the lower limit S2min of the heating amount S2 is set to 800W, and intermediate values ​​of the heating amount S2 between these are set to 840W, 880W, 920W, and 960W. In this case, the heating amount S2 of the bottom heater 11 may have any number of intermediate values, for example, 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: an intense flame has one cycle C of 1 second, a gentle flame has one cycle C of 4 seconds, a soft flame has one cycle C of 7 seconds, and a quiet flame has one cycle C of 10 seconds. For example, in order to achieve a medium heat and a gentle flame during the period from when the rice is boiling to when the rice is cooked through during the "boiling heating" process, one cycle C is set to 4 seconds, and the output maintenance time D for each cycle is set to 0.4 seconds. However, 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, corresponding to one cycle C that corresponds to an intense flame. 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, corresponding to one cycle C that corresponds to a soft flame. The output maintenance time D does not have to be constant for all outputs during a cycle, and can be changed arbitrarily for each output.

[0046] As another example, in the case of low heat as described above, during one cycle C in which the heating amount fluctuation means 44 changes the output of the inverter 37 from 500W → 540W → 580W → 620W → 660W → 700W → 660W → 620W → 580W → 540W → back to 500W, the upper limit value S2max of the heating amount S2 is set to 700W, the lower limit value 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 value S2max and the lower limit value S2min, multiple intermediate values ​​are changed in a cyclical and repeated manner. In this case, too, there may be any number of intermediate values ​​for the heating amount S2 of the bottom surface heater 11, and the value of each output may be set arbitrarily, such as increasing or decreasing the heating amount S2 between 500 W and 700 W in increments of 20 W or 50 W instead of in increments of 40 W. 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, by adding one or more intermediate heat amount S2 values ​​in addition to the upper limit value S2max and lower limit value S2min of the heat amount S2, it becomes possible to cook the food A in the pot 7 with heating that is closer to cooking in a stove with flickering flames from a wood fire.

[0048] In this embodiment, the heat quantity fluctuation means 44 is configured to vary the heat quantity 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 quantity S2 in an irregular pattern, or by mixing an irregular pattern with a regular pattern.

[0049] "Fluctuation" refers to unpredictable spatial or temporal changes or movements, 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 firewood fire are included in the category of "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 was described as periodically repeating the time-dependent change in the heating amount S2 equivalent to a preset fluctuation for each cycle C. However, the fluctuation pattern may also be configured to change irregularly from a predetermined setting by triggering a change in the cooking state that changes as the pot 7 is heated, for example, in response to 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, thereby 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).

[0052] Specific examples will be described below with reference to Figures 6 to 8. Figure 6 is a graph showing the temperature changes over time in various parts of pot 7 during the boiling heating process in the rice cooker of this embodiment. In the figure, Tn indicates the change in the temperature of the bottom of the pot, which is the temperature detected by pot temperature sensor 15; Ts indicates the change in the temperature 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 in the upper part of pot 7 is faster than that in the lower part; Tf(C) indicates the change in the lid temperature when the temperature rise in the upper part of pot 7 is slower than that in the lower part; (d) indicates boiling detection due to a change in the rate of temperature rise of lid temperature Tf; (e) indicates boiling detection due to a change in the rate of temperature rise of pot bottom temperature Tn; and (H) indicates heating adjustment until boiling.

[0053] When the rice cooking control means 41 controls the process to boil and heat the pot 7 at a high heat level S from the bottom heater 11, which produces the intense flame 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 rate of temperature rise (g) of the lid temperature Tf from immediately after the start of the boil and heat process, relative to the rate of temperature rise (f) until the pot bottom temperature Tn reaches the predetermined temperature of 80°C, is smaller than the predetermined rate of temperature rise, it is clear that the temperature rise in the upper part of the pot 7 is slow. Possible causes for this include a weak heating level, a large amount of water for the food item A to be cooked, or cold water. In such cases, traditional cooking stoves would empirically increase the firewood fire to adjust the heat.

[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, increases and temporarily changes during the period of heating adjustment (H) until boiling thereafter.

[0055] In other words, in the above example, in order to heat to a boil in the "heating to boil" process, the heating amount fluctuation means 44 set the lower limit S2min to 1200W and the upper limit S2max to 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 extended from 100ms (0.1 seconds) to 500ms (0.5 seconds), thereby temporarily increasing the heating amount S2 of the 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 monitors the temperature state of the upper layer inside pot 7 based on the change in lid temperature Tf measured by lid temperature sensor 16, using as a reference point the point (X) 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 leading up to boiling and boiling is detected, and adjusts heating amount S2 according to the fluctuation pattern after boiling is detected based on the monitoring results.

[0057] As shown in Figure 7, lid temperature Tf, which is the temperature detected by lid temperature sensor 16, rises rapidly when the upper layer of pot 7 begins to boil. The phenomenon of lid temperature Tf rising 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 determines the time difference between the point (X) when the pot bottom temperature Tn measured by pot temperature sensor 15 falls below a predetermined value for a predetermined time, i.e., the point (X) when boiling is detected and the point 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 point (X) when boiling is detected at pot bottom temperature Tn, it is possible that the amount of heat is too strong, 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 predetermined value occurs later than the point at which boiling is detected at the pot bottom temperature Tn (X), it is possible that the amount of heating was too weak, or 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.

[0059] 8, heat amount fluctuation means 44 uses the point (X) when boiling is detected at the aforementioned pot bottom temperature Tn as a reference point and determines the time difference between that point and the point when lid temperature Tf falls below a predetermined value within a predetermined time, i.e., the rate of temperature rise (d) of lid temperature Tf falls below a predetermined value and boiling is detected by lid temperature sensor 16. If the rate of temperature rise (d) of lid temperature Tf falls below the predetermined value after a delay within the predetermined time from the point (X) when boiling is detected at the pot bottom temperature Tn, this may indicate that the amount of heat was too strong, the amount of water was too small, or the water temperature was too high, and so heat amount fluctuation means 44 reduces the heat amount S2 of pot 7 while boiling continues. Conversely, if the time when the temperature rise rate (d) of the lid temperature Tf falls below a predetermined value is delayed by more than a predetermined time from the time (X) when boiling is detected at the pot bottom temperature Tn, 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] In the above example, the heating amount fluctuation means 44 periodically and repeatedly changes the heating amount S2 in a 4-second cycle C with a lower limit S2min of 800 W and an upper limit S2max of 1000 W to achieve a medium, gentle flame during the "boiling heating" process until the rice is cooked through. However, to increase the heating amount S2 according to the fluctuation pattern after boiling is detected, the lower limit S2min can be 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 can be made longer than the predetermined time of 400 ms (0.4 seconds). Conversely, to decrease the heating amount S2 according to the fluctuation pattern after boiling is detected, the upper limit S2max can be decreased from 100 W to 900 W, or the output maintenance time D during which the heating amount S2 is maintained at 900 W can be 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, based on the relationship between the temperature changes detected by the pot temperature sensor 15 and the lid temperature sensor 16, particularly during heating up to boiling or heating while boiling continues. However, it is also possible to temporarily generate an irregular pattern or a regular pattern mixed with an irregular pattern for fluctuations in the amount of heat S2 during other rice cooking processes, such as when cooking the rice or soaking it. Furthermore, the trigger for generating such an irregular pattern is not limited to the relationship between the temperature changes detected by the pot temperature sensor 15 and the lid temperature sensor 16, and it is also possible to consider the relationship between the pressure changes detected by the pressure sensor 17, etc.

[0062] That is, in traditional cooking using a stove, the heat of the firewood is adjusted using the five human senses as sensors, such as the state of the firewood, the amount of steam and vapor, the time when the boiling sound occurs, the strength and duration of steam generation, and the aroma, but the heat is not the same every time, but is flexibly adjusted 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 cooking progress state, such as the temperature and pressure during cooking and the generation of steam.

[0063] Therefore, when pressurizing the pot 7 during boiling, the fluctuations in the amount of heat S2 thereafter may be temporarily changed to a pattern that includes irregularities when the pot 7 reaches a boiling state 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.

[0064] In this embodiment, the heat amount fluctuation means 44 is used to make the heat amount S2 of the bottom heating element 11 have an irregular pattern, or to make it a pattern that is a mixture of a regular pattern and an irregular pattern, so that the food A in the pot 7 can be cooked with heating that is closer to cooking in a stove with flickering flames from a wood fire.

[0065] In addition, the control unit 31, which is equipped with AI (artificial intelligence) functions, can learn how to adjust the next heating depending on the cooking progress, such as the temperature and pressure during cooking and the generation of steam, 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 changes in heating of pot 7 over time caused by rice cooking control means 41, which follows the traditional fire control for cooking in a traditional Japanese stove described above, "start with a trickle, then a pop, when it starts to sizzle, turn off the heat, burn a handful of straw, and don't take the lid off even if the baby cries," 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 cooking step progresses, and a second pattern is generated in which the output of inverter 37, which corresponds to the amount of heat from bottom heater 11, changes to about 200 W overall, and the heat amount S2 based on this second pattern is given to pot 7 by heat amount fluctuation means 44, which adds a heating configuration that takes into account the fluctuations of a firewood flame.

[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 pappa", 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, and In the heating while boiling continues in the boiling heating process corresponding to "burning a handful of straw, don't take the lid off even if the baby cries," the inverter 37 outputs a medium heat of 800W to 1000W, and a gentle flame heat amount S2 of 4 seconds for one cycle C 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, don't take the lid off even if the baby cries," the inverter 37 outputs a low heat of 500W to 700W, and a gentle flame heat amount S2 of 10 seconds for one cycle C is given to the pot 7.

[0069] In this embodiment, the heating amount fluctuation means 44 changes the upper limit S2max and lower limit S2min associated with the time element of the heating 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 cooking in a stove with flickering flames from a wood fire.

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

[0071] 9 shows the relationship between the heating amount S2 and time at high heat when the inverter 37 output is 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 levels of heating amount S2: 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 level, i.e., 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] Figure 10 shows the relationship between the heating amount S2 and time at medium heat when the inverter 37 output is in the range of 800W to 1000W in the above example. As shown in Figure 10(B), the heating amount fluctuation means 44 sets the heating amount S2 corresponding to medium heat from six levels of heating amount S2: 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 level. For comparison, Figure 10(A) shows an example in which the heating amount S2 is continuously and steplessly varied by the heating amount fluctuation means 44.

[0073] Figure 11 shows the relationship between the heating amount S2 and time at low heat when the inverter 37 output is in the range of 500W to 700W in the above example. As shown in Figure 11(B), the heating amount fluctuation means 44 sets the heating amount S2 corresponding to low heat from six levels of heating amount S2: 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, Figure 11(A) shows an example in which the heating amount fluctuation means 44 continuously and steplessly varies the heating amount S2.

[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 essential parts of high, medium, and low heat, for example, from multiple stages of heating amounts including an upper limit value S2max, a lower limit value S2min, and an intermediate value. Therefore, there is no need 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, making it possible to miniaturize the inverter 37.

[0075] The heating amount fluctuation means 44 of this 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 rated power consumption of rice cookers is regulated by the Electrical Appliance and Material Safety Act. In the example described above, even if the inverter 37 is set to output 1200W to 1400W on high heat, power consumption fluctuates over time, making it difficult to inspect power consumption on a manufacturing assembly line, etc. Therefore, in this embodiment, the control unit 31, which includes the rice cooking control means 41 and the heating amount fluctuation means 44, controls and limits the inverter 37 output, corresponding to the upper limit S2max of the heating amount S2, so that it does not exceed the rated power consumption of the rice cooker, or, if it does exceed it, it does so by no more than 5%. Specifically, if the rated power consumption of the rice cooker is 1400W, the inverter 37 output is limited to 1470W or less. The control unit 31 of the rice cooker may also be equipped with an inspection means (not shown) that operates the inverter 37 at an output of 1400W for, for example, 60 seconds or continuously for a predetermined period of time as a test mode for inspection.

[0077] However, the rated power consumption of a rice cooker may include not only heating from the bottom heating element 11 to the pot 7 by the heating coil, but also heating of the lid 2 by the lid heating element 18 and heating of the sides 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 value S2max of the heating amount S2, to 1350 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 inverter 37 outputs a high flame in the range of 1200 W to 1400 W, and the lower limit S2min of the heating amount S2 is set to 1200 W. However, 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 of the heating amount S2 so that it does not fall below 50% of the upper limit S2max. In other words, if the upper limit S2max of the heating amount S2 is set to 1400 W, the lower limit S2min of the heating amount S2 is limited to not fall below 700 W.

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

[0080] The heat amount fluctuation means 44 of this 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] Cooking methods such as the rice cooking control means 41 detecting the amount of food A to be cooked (rice cooking amount) placed in the pot 7 and changing the heating pattern as a first pattern depending on the amount of rice to be cooked, selecting brown rice, polished rice, local variety brand rice, etc. through operation of the operation unit 4 and cooking rice with a heating pattern according to the rice quality, and varying the cooked texture such as firm, soft, sticky, or sweet through operation of the operation unit 4 and cooking rice with a heating pattern according to that are well known in the art. In this embodiment, in addition to the various conventional rice cooking methods performed by the rice cooking control means 41, a specific second pattern that enables the heating amount fluctuation means 44 to control the fluctuation of the heating amount S2 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 can be selected, which enables appropriate fluctuation control of the heating amount S depending on the amount of rice to be cooked, the rice cooking menu, the cooking method, and the rice producing area, variety, and brand.

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

[0084] 7. Hot Pot 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 pot; 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, and 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 respectively The heating step until boiling > the heating step during boiling > the soaking cooking step, and The heating step until boiling > the heating step while boiling continues > the steaming step 2. The rice cooker according to claim 1, wherein

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