JP4075648B2 - Electric rice cooker and how to determine the amount of rice cooked - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric rice cooker and a method for determining the amount of rice cooked, and more particularly to a method for determining the amount of rice cooked in a water-absorbing process that promotes water absorption of rice grains while heating with weak thermal power before heating with strong thermal power.
[0002]
[Prior art]
In an electric rice cooker equipped with a microcomputer as a control means, the microcomputer controls the output of the heating means (electric heater or IH coil) of the inner pot according to a program stored in the memory in advance, so that proper rice cooking control is achieved. Is executed. At this time, an output signal (detected temperature) of a temperature sensor for detecting the temperature of the inner pot is fed back to the microcomputer, and the microcomputer controls the output of the heating means based on the detected temperature.
[0003]
Such rice cooking control includes, for example, a water absorption process, a temperature raising process, a boiling process, a cooking process, and a steaming process. In the water absorption process, water absorption of rice grains is promoted while heating the inner pot with a weak heating power. In the temperature raising step, the inner pot is heated with a strong heating power so that the detected temperature rises to about 100 ° C. with a large gradient. In the boiling process, the rice is cooked in boiling water while maintaining a strong thermal power. In the boiling process, the detected temperature is maintained at about 100 ° C. After a while, when the water in the inner pot evaporates and disappears, the cooking process is started. In the cooking process, when the detected temperature rises rapidly from about 100 ° C. and reaches a predetermined temperature, the output of the heating means is lowered and the process proceeds to the steaming process. In the steaming step, the output of the heating means is controlled so that the detected temperature is maintained at a predetermined uneven temperature for a predetermined time.
[0004]
In the rice cooking control as described above, the amount of rice cooking (sometimes referred to as the total number), which is the amount of rice in the inner pot, is determined from the temperature rise gradient in the temperature raising step, and the subsequent heating amount is adjusted based on the determination result To be done. That is, if the output of the heating means is constant, the temperature rise gradient is reduced in proportion to the amount of rice cooked, so the amount of rice cooked is determined by detecting the temperature rise per unit time or the amount corresponding thereto. And in the subsequent process, control is performed such that the heating amount is increased as the amount of cooked rice is larger.
[0005]
However, when the amount of cooked rice is determined in the temperature raising step, the subsequent heating amount can be adjusted based on the determination result. For example, the output of the heating means is set from the beginning of the temperature raising step. It is not possible to perform control that adjusts according to the condition. In the case where the output of the heating means is the same, the time required for the temperature raising process greatly changes when the amount of cooked rice changes greatly. Therefore, it is desirable to adjust the output of a heating means according to the amount of rice cooking.
[0006]
Therefore, for example, as disclosed in Patent Document 1, a method of determining the amount of rice cooking in a water absorption process (referred to as a pre-cooking process in Patent Document 1) has been proposed. In this determination method, the heating means is controlled so as to maintain the detected temperature of the inner pot at a predetermined temperature in the water absorption process, and the amount of cooked rice is determined by measuring the degree of energization of the heating means at this time.
[0007]
[Patent Document 1]
JP-A-2-277420
[0008]
[Problems to be solved by the invention]
In the method for determining the amount of cooked rice disclosed in Patent Document 1, it is necessary to maintain the temperature detected by the inner pot at a predetermined temperature in the water absorption process. However, according to the experiment results of the inventors, the cooked state of the rice is better when the detection temperature is gradually increased (with a small gradient) than when the detection temperature is kept constant in the water absorption process. I understood that.
[0009]
For example, compared to the conventional water absorption process in which the water absorption temperature (detection temperature) is maintained at about 45 ° C., if the water absorption temperature is set to a temperature slightly higher than 50 ° C., the water absorption rate of the rice will increase and a more delicious rice will be produced. I knew I could cook. However, when the amount of cooked rice is large, a predetermined time (for example, 10 minutes) elapses before the detected temperature reaches 50 ° C., and the water absorption process ends. In addition, when the water absorption temperature is set too high, such as 65 ° C. or 70 ° C., when the amount of cooked rice is small, the temperature of the rice rises too much and a gelatinization phenomenon occurs.
[0010]
Therefore, if the detection temperature is gradually raised in the water absorption process, the temperature of the rice will not rise too much in the water absorption process even if the amount of rice cooked is small, and gelatinization will not occur. Will improve. As a result, the cooked state of rice is improved (delicious rice can be cooked).
[0011]
The present invention has been made based on the experimental results as described above. In the water absorption process, the rice cooking amount is determined while gradually increasing the detected temperature of the inner pot, and the subsequent heating amount is determined as the rice cooking amount. The purpose is to be able to adjust according to the result.
[0012]
[Means for Solving the Problems]
An electric rice cooker according to the present invention includes a temperature sensor for detecting the temperature of the inner pot, a control means for performing rice cooking control by controlling the heating means of the inner pot according to the temperature detected by the temperature sensor, and rice cooking And an operation unit including a rice cooking switch to start the rice cooking control executed by the control means, A water absorption step of maintaining the temperature for a predetermined time after the detected temperature rises to the first set temperature; and The detected temperature is Said Rise from the first set temperature to the second set temperature with a small gradient Includes 2 steps of water absorption The water absorption step for controlling the heating means, and the detected temperature Than the gradient in the two water absorption steps A heating step for controlling the heating means so as to rise to about 100 ° C. with a large gradient, a boiling step for maintaining the detected temperature at about 100 ° C., and the detected temperature rapidly rising from about 100 ° C. A cooking step for reducing the output of the heating means when the temperature reaches a predetermined temperature, and the control means comprises the water absorption 2 Process The heating means is controlled to be turned on and off so that the detected temperature rises stepwise from the first set temperature to the second set temperature over a predetermined time. Or based on the integrated value of off time, The rice cooking amount is determined from the relationship between the output of the heating means and the temperature rise gradient, and the heating amount in the subsequent process is adjusted based on the rice cooking amount.
[0013]
According to such a configuration, the rice cooking amount can be determined while gradually increasing the temperature detected in the inner pot in the water absorption step, and the subsequent heating amount can be adjusted according to the determination result of the rice cooking amount. In addition, since the temperature of the inner pot is gradually increased in the water absorption process, the water absorption rate of rice is improved even when the amount of cooked rice is large. Will not occur.
[0015]
Also, The control means performs on / off control of the heating means so that the detected temperature gradually increases from the first set temperature to the second set temperature over a predetermined time in the water absorption step, and at the predetermined time The amount of cooked rice is determined based on an integrated value of on time or off time of the heating means. thing Thus, it becomes possible to determine the amount of rice cooking almost accurately while gradually increasing the detected temperature in the water absorption step.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0021]
Drawing 1 is a sectional view seen from the side of the electric rice cooker concerning the embodiment of the present invention. This electric rice cooker includes a case body 11 made of synthetic resin, a metal inner pot 12 detachably mounted in the interior space thereof, and a rear portion of the case body 11 so as to open and close an upper opening of the case body 11 (see FIG. 1 includes a lid member 14 pivotally supported by a shaft 13 on the right side. An inner lid 15 that seals the upper opening of the inner hook 12 is provided inside the lid member 14.
[0022]
The inner pot 12 is made of a magnetic metal such as a stainless steel plate or a metal containing a magnetic substance. Near the bottom of the inner pot 12, an IH coil (corresponding to a heating means) 16 for heating the inner pot 12 by induction heating (IH) is provided. When the IH coil 16 is driven with an alternating current, the magnetic flux of the alternating magnetic field generated by the IH coil 16 causes the inner hook 12 to generate an eddy current. The inner pot 12 generates heat due to this eddy current and its own electrical resistance.
[0023]
Further, a side heater 18 for heat insulation is provided in a ring shape on the side portion of the holding member 17 of the inner hook 12. Further, an upper heater 19 for heating the inner lid 15 of the lid member 14 by heat conduction to prevent condensation is provided in a ring shape. A temperature sensor 20 for detecting the temperature of the inner hook 12 is provided at the center of the bottom of the inner hook 12.
[0024]
An operation panel 21 including an operation unit and a display unit is provided on the upper part of the front surface (left side in FIG. 1) of the electric rice cooker, and a first control board 22a is provided on the inner side. A second control board 22b is provided in a space below the first control board 22a. On these control boards 22 (22a + 22b), a microprocessor, a temperature detection circuit, a buzzer, a power supply circuit, and the like are mounted.
[0025]
FIG. 2 is a block diagram showing a configuration of an electric circuit of the electric rice cooker including the control board. As shown in this figure, a microcomputer (MPU) 29 as control means, an oscillation circuit 28 and a power / reset circuit 25 are provided. The detection signal of the temperature sensor 20 is input to the microcomputer 29 via the temperature detection circuit 26. In addition, signals from the operation unit 27 including various push button switches described later are input to the microcomputer 29.
[0026]
The IH coil 16 described above is driven and controlled by the microcomputer 29 via the IH drive circuit 24. The IH drive circuit 24 is configured using a switching element such as an IGBT, a diode, a resonance capacitor, and the like, and supplies a predetermined high-frequency current to the IH coil 16. The side heater 18 and the upper heater 19 are on / off controlled by a microcomputer 29 via a heater drive circuit 30.
[0027]
In addition, a buzzer 31 for notifying of cooking and a key operation sound is provided, and this is also controlled by the microcomputer 29. Further, the display unit 32 provided on the operation panel 21 is constituted by a liquid crystal display, and the display content is set by the microcomputer 29.
[0028]
Drawing 3 is a figure showing the example of composition of the operation panel of an electric rice cooker. The operation panel 21 includes an operation unit 27 and a display unit 32. The operation unit 27 includes a rice cooking switch 37, a reservation switch 38, a menu switch 39, a time setting switch 40, a cancel switch 42, and a heat retention switch 43. When the rice cooking switch 37 is pressed, rice cooking is started and the rice cooking indicator (LED) 37a is turned on.
[0029]
The reservation switch 38 is used for setting a rice cooking reservation. When the reservation switch 38 is pressed, the cooking time (reservation time) can be set using the time display part (7-segment display part) 45 and the time setting switch (hour / minute switch) 40 of the display part 32. . Thereafter, when the rice cooking switch 37 is pressed, the reservation time is stored in the built-in memory of the microcomputer 29, and the reservation indicator (LED) 38a is turned on. At this time, the completion of the reservation setting is notified by the sound of the buzzer 31. The microcomputer 29 controls the cooking so that the rice is cooked at the approximate reservation time, starting from the time before the reservation time by the time necessary for cooking. In the reservation setting, two different times can be set, and the display unit 32 distinguishes between reservation 1 and reservation 2 indicators.
[0030]
The menu switch 39 is used for setting a rice cooking menu. When the menu switch 39 is pressed, the menu that is lit on the upper side of the display unit 32 changes in order of white rice, quick cooking, and rice porridge, and the lit menu is selected. If the menu switch 39 is not pressed, white rice is set as a default.
[0031]
The time setting switch 40 is used for the reservation setting of the rice cooking time and the setting of the current time. When the hour and minute switches are pressed, the upper two digits (hours) or the lower two digits (minutes) of the time display unit 45 are incremented. The cancel switch 42 is used for canceling reservation settings, heat retention, and the like.
[0032]
The heat retention switch 43 is used to start the heat retention of the rice. Normally, when the cooking process is completed, the warming process starts automatically, but when the warming is canceled with the cancel switch 42 or when the power plug is removed, the warming process starts again when the warming switch 43 is pressed. . During the warming, the warming indicator (LED) 43a is turned on.
[0033]
FIG. 4 is a graph illustrating how the inner pot temperature changes in the rice cooking control of the electric rice cooker according to the embodiment of the present invention. The inner pot temperature is a temperature detected by the microcomputer 29 based on the detection signal of the temperature sensor 20 described above. In this rice cooking control, the IH coil 16 is first driven so as to increase the inner pot temperature (detected temperature) at a stretch to the first set temperature (for example, 50 ° C.), and then the first set temperature to the second set temperature (for example, the detected temperature). On / off control of the IH coil 16 is performed so as to gradually increase the temperature of the inner pot up to (60 ° C.) (water absorption step 45). During this time, water absorption of rice is promoted, and the amount of cooked rice (total number) is determined. The rice cooking amount determination process in the water absorption step 45 will be described in detail later.
[0034]
In the subsequent temperature raising step 46, the IH coil 16 is energized with a predetermined electric power, whereby the inner pot temperature rapidly rises. The power supplied to the IH coil 16 in the temperature raising step 46, that is, the heating output is adjusted according to the determination result of the rice cooking amount in the water absorption step 45. That is, the heating output is set to increase as the amount of cooked rice increases.
[0035]
Eventually, the water (hot water) in the inner pot 12 boils, and the process proceeds to a boiling step 47 where rice is cooked (boiled) in boiling water. During the boiling step 47, water gradually evaporates, and the inner pot temperature is maintained at about 100 ° C. As hot water in the inner pot 12 evaporates and disappears, the process proceeds to the cooking step 48.
[0036]
In the cooking process 48, when the temperature of the inner pot reaches a predetermined cooking temperature (for example, 130 ° C.), the power supplied to the IH coil 16 is lowered and maintained at a predetermined uneven temperature (107 ° C.) for about 10 minutes. (Spotting step 49). The rice is now cooked and rice cooking control is complete. Thereafter, the process automatically proceeds to the heat retaining step 51 through the cooling step 50.
[0037]
In the cooling step 50, the process waits for the temperature of the inner pot to drop to a heat retaining temperature (for example, about 70 ° C.) by natural cooling. Thereafter, temperature control is performed to maintain the inner pot temperature at the heat retaining temperature by on / off control of the IH coil 16 while energizing the side heater 18 and the upper heater 19 with a predetermined duty factor (heat retaining step 51). .
[0038]
In the heat retention step, low temperature heat retention may be performed first, and heat retention control may be performed in which the heat retention temperature is increased step by step as time elapses. For example, the cooling process 50 waits for the temperature of the inner pot to drop to around 65 ° C., initially, the low temperature is kept at about 65 ° C., and after a few hours, the temperature is raised to about 68 ° C., the middle temperature is kept, After a period of time, the temperature is increased to about 72 ° C. to perform high temperature heat insulation. By carrying out like this, it can suppress decay, when the heat retention becomes long time, suppressing deterioration of a rice by heat insulation for a short time.
[0039]
Also, in the above three-stage heat retention, when shifting from low temperature heat retention to medium temperature heat retention, and when shifting from medium temperature heat retention to high temperature heat retention, IH is set so that the inner pot temperature temporarily becomes 100 ° C. or higher for a very short time. The coil 16 may be controlled. Thereby, propagation of spoilage bacteria can be suppressed.
[0040]
FIG. 5 is a graph illustrating a change in the inner pot temperature in the water absorption process in a simplified manner. In this example, the water absorption process is divided into a water absorption process 1, a water absorption process 2, and a water absorption process 3, and the rice cooking amount determination (total number determination) is executed in the water absorption process 2. In one embodiment, the water absorption 1 step is 5 minutes, the water absorption 2 step is 10 minutes, and the water absorption 3 step determines the time according to the result of the total number determination.
[0041]
FIG. 6 is a flowchart showing an example of processing in one water absorption process. In the water absorption 1 step, the inner pot temperature is raised to the first set temperature T1 (for example, 50 ° C.) and then maintained at this temperature. In step # 101, a water absorption 1 timer (for example, 5 minutes) is started. In the next step # 102, it is checked whether the inner pot temperature (detected temperature) is equal to or higher than T1 (for example, 50 ° C.). If it is lower than T1, the IH coil 16 is turned on with a duty factor of 16/16 (step #). 103). If the inner pot temperature is equal to or higher than T1, the IH coil 16 is turned off (step # 104). The supply power (heating output) to the IH coil 16 can be adjusted by phase control in addition to the adjustment by the duty factor. The adjustment amount by phase control is, for example, 70% output.
[0042]
In the subsequent step # 105, the upper heater 19 is turned on with a duty factor of 6/16 to prevent condensation of the inner lid 15. In the next step # 106, the water absorption 1 timer is checked. Until the water absorption 1 timer expires (time up), the processing from step # 102 to step # 106 is repeated, and the inner pot temperature is maintained at the first set temperature T1. When the water absorption 1 timer (for example, 5 minutes) is completed, the process proceeds to the next water absorption 2 process.
[0043]
Returning to FIG. 5, in the second water absorption step, the IH coil 16 is controlled so as to gradually increase the inner pot temperature from the first set temperature T1 to the second set temperature T2 (for example, 60 ° C.). At this time, the two water absorption steps (t1 to t2) are divided into m sections (m = 10 in FIG. 5). That is, Δt = (t2−t1) / m. Similarly, the temperature difference from the first set temperature T1 to the second set temperature T2 is divided into m pieces. That is, ΔT = (T2−T1) / m. Then, the total number is determined by the following on / off control of the IH coil 16 and integration of the off time.
[0044]
FIG. 7 is an enlarged graph showing a change in the inner pot temperature in the two water absorption steps in FIG. As can be seen from this figure, in each Δt section, the IH coil 16 is turned on until the inner pot temperature reaches the set temperature (T1 + kΔT), and when it reaches the set temperature (T1 + kΔT), the on / off control of the IH coil 16 is performed. Temperature control is performed. However, k = 1, 2,..., M.
[0045]
As shown in FIG. 7, the off times (approximately half of the temperature adjustment time) of the temperature adjustment times tc1, tc2,..., Tcm by the on / off control of the IH coil 16 in each Δt interval are toff1, toff2 ,..., Toffm, and the total toff of these off times is obtained. That is, toff = toff1 + toff2 + ... + toffm. The total toff of the off time becomes shorter as the amount of cooked rice (total number) is larger. Therefore, the amount of rice cooking (total number) can be determined from the total toff of the off time.
[0046]
In addition, you may obtain | require the total of ON time instead of the OFF time of the IH coil 16 in each (DELTA) t area. In this case, the total ton of on-time becomes longer as the amount of cooked rice (total number) is larger.
[0047]
FIG. 8 is a flowchart illustrating an example of processing of two water absorption steps including determination of the amount of rice cooked. In step # 201, the toff timer is cleared and 1 is substituted for k. The toff timer is a timer for accumulating the total toff of the off time. Here, a value of m (for example, 10) may be set.
[0048]
In the next step # 202, the Δt timer is started. The Δt timer is a timer for measuring the above-described Δt interval. Δt = (t2−t1) / m. For example, when the time of the two water absorption steps (t1 to t2) is 10 minutes and m = 10, Δt is set to 1 minute.
[0049]
In the next step # 203, a target temperature Tk for each Δt section is set. That is, T1 + kΔT is substituted for Tk. As shown in FIG. 7, for example, the target temperature in the first Δt section is Tk = T1 + ΔT (for example, 51 ° C.), and the target temperature in the second Δt section is Tk = T1 + 2ΔT (for example, 52 ° C.).
[0050]
In the next step # 204, it is checked whether or not the inner pot temperature (detected temperature) is equal to or higher than Tk. If it is lower than Tk, the IH coil 16 is turned on with a duty factor 16/16 (step # 205). The amount of adjustment by phase control of the IH coil 16 is, for example, 70% output. If the inner pot temperature is equal to or higher than Tk, the IH coil 16 is turned off (step # 206), and the toff timer is integrated (timed) (step # 207).
[0051]
In the next step # 208, the Δt timer is checked. Until the Δt timer expires (time up), the processing from step # 204 to step # 208 is repeated. As a result, as shown in FIG. 7, temperature control times tc1, tc2,..., Tcm in which the inner pot temperature is maintained at approximately Tk are provided in the latter half of each Δt interval. As described above, a part of the temperature control times tc1, tc2,..., Tcm (about half time) corresponds to the off times toff1, toff2,.
[0052]
As a modification of FIG. 7, the inner pot temperature as shown in FIG. 9 may be controlled. In other words, in the latter half of the Δt interval, off times toff1, toff2,..., Toffm for turning off the energization of the IH coil 16 are provided instead of the temperature adjustment time by the on / off control of the IH coil 16. In this case, the control from step # 204 to step # 208 may be slightly changed in the flowchart of FIG. For example, the flag may be set when the inner pot temperature reaches Tk, and control may be performed so that the IH coil 16 is not turned on until the Δt timer ends from that point.
[0053]
If the Δt timer expires in step # 208, the value of k is incremented in the next step # 209. In subsequent step # 210, the value of k is compared with m (for example, 10), and the processing from step # 202 to step # 210 is repeated until k exceeds m. In this way, the integrated value of the time toff when the IH coil 16 is turned off is obtained while increasing the inner pot temperature stepwise only during the time t2−t1 = mΔt. In the flowchart of FIG. 8, there is no timer for measuring the time of 2 steps of water absorption (for example, 10 minutes), but this is because an equivalent function can be achieved by repeating the Δt timer m times. . However, a timer for measuring the time of the two water absorption steps may be provided for safety.
[0054]
The integrated value toff of the off time obtained as described above is a value inversely proportional to the amount of rice cooking (total number) as described above. That is, the larger the amount of cooked rice, the smaller the integrated value toff of the off time.
[0055]
In the next three water absorption steps, as shown in FIG. 5, the IH coil 16 is maintained at a third set temperature T3 (for example, 70 ° C.) higher than the second set T2 for a predetermined time (t3-t2). The energization control is performed. At this time, the third set temperature T3 and the predetermined time (t3-t2) are set according to the integrated value toff of the off time that is the determination value of the rice cooking amount.
[0056]
FIG. 10: is a flowchart which shows the example of the process of the water absorption 3 process which changes according to the determination value of rice cooking amount. In this example, the amount of cooked rice is determined to be three stages of small, medium, and large, and if the amount of cooked rice is less than the predetermined amount (if it is small), the water absorption step 3 is not executed and the process immediately proceeds to the next temperature raising step. To do. When the amount of cooked rice is a predetermined amount or more (in the case of medium or large), the values of the third set temperature T3 and the water absorption 3 timer are set according to each.
[0057]
First, in step # 301, an integrated value toff of off time (corresponding to the reciprocal of the amount of cooked rice) is determined. If toff is equal to or greater than the predetermined value (Yes in step # 302), it means that the amount of cooked rice is less than the predetermined amount, and the process immediately proceeds to the temperature raising step. When toff is smaller than the predetermined value (No in step # 302), the third set temperature T3 and the water absorption 3 timer are set according to the value of toff (step # 303).
[0058]
As described above, in this example, two types of the third set temperature T3 and the water absorption 3 timer are set according to whether the value of toff is medium or small (that is, whether the amount of rice cooking is medium or large). Generally, as the value of toff is smaller (that is, as the amount of cooked rice is larger), the third set temperature T3 is set higher and the water absorption 3 timer is set longer. Only one of the third set temperature T3 and the water absorption 3 timer may be changed according to the value of toff.
[0059]
In the next step # 304, the water absorption 3 timer is started, and in the subsequent step # 305, it is checked whether or not the inner pot temperature (detected temperature) is equal to or higher than T3. If the inner pot temperature is lower than T3, the IH coil 16 is turned on with a duty factor of 16/16 (step # 306). If the inner pot temperature is equal to or higher than T3, the IH coil 16 is turned off (step # 307). Note that the amount of adjustment by phase control of the IH coil 16 is, for example, 70% output.
[0060]
In the subsequent step # 308, the upper heater 19 is turned on with a duty factor of 6/16 to prevent condensation on the inner lid 15. In the next step # 309, the water absorption 3 timer is checked. Until the water absorption 3 timer expires (time up), the processing from step # 305 to step # 309 is repeated, and the inner pot temperature is maintained at the third set temperature T3. When the water absorption 3 timer ends, the process proceeds to the next temperature raising step.
[0061]
By the control as described above, the energization of the IH coil 16 is controlled so as to gradually (stepwise) increase from the first set temperature T1 to the second set temperature T2 in the water absorption process (of which 2 are the water absorption processes). . And during this time, the amount of rice cooking (total number) is determined based on the off time of the IH coil 16, and the amount of heating by the IH coil 16 after the three water absorption steps is adjusted according to the determination result of the rice cooking amount.
[0062]
As mentioned above, although embodiment of this invention was described with some modifications, this invention can be implemented with a various form other than these embodiment and modifications.
[0063]
The present invention is not limited to an electric rice cooker (so-called IH jar) that performs rice cooking control using an induction heating type heating means (IH coil), but also an electric rice cooker (so-called microcomputer jar) that performs rice cooking control using an electric heater. It can also be applied to.
[0064]
【The invention's effect】
As explained above, according to the electric rice cooker of the present invention and the rice cooking amount determination method, the rice cooking amount is determined while gradually increasing the detected temperature of the inner pot in the water absorption step, and the output of the subsequent heating means Can be adjusted according to the determination result of the amount of cooked rice. Since the temperature detected in the inner pot gradually increases during the water absorption process, even if the amount of rice cooked is large, the water absorption rate of the rice is improved, and even when the amount of rice cooked is small, the temperature of the rice rises too much and the gelatinization phenomenon occurs. There is nothing to do.
[0065]
In addition, compared to the method of determining the amount of rice cooked in the temperature rising step with a steep temperature rise, the amount of rice cooked is determined in the water absorption step of gradually increasing the temperature, so even if the amount of rice cooked is small, the determination accuracy of the rice cooking amount is high A better effect is also obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an electric rice cooker according to an embodiment of the present invention as viewed from the side.
FIG. 2 is a block diagram showing a configuration of an electric circuit of an electric rice cooker including a control board.
FIG. 3 is a diagram showing a configuration example of an operation panel of an electric rice cooker.
FIG. 4 is a graph illustrating a state in which the inner pot temperature changes in the rice cooking control of the electric rice cooker according to the embodiment of the present invention.
FIG. 5 is a graph exemplifying a change in the inner pot temperature in the water absorption process.
FIG. 6 is a flowchart showing an example of processing in one water absorption step.
7 is an enlarged graph showing a change in the inner pot temperature in the two water absorption steps in FIG. 5. FIG.
FIG. 8 is a flowchart showing an example of processing of two water absorption steps including determination of the amount of rice cooking.
FIG. 9 is a graph showing a modification of FIG.
FIG. 10 is a flowchart showing an example of a process of three steps of water absorption that changes in accordance with a determination value of the amount of cooking rice.
[Explanation of symbols]
12 Inner pot
16 IH coil (heating means)
18 Side heater
19 Upper heater
20 Temperature sensor
27 Operation unit
29 Microcomputer (control means)
37 Rice cooker switch

Claims (1)

Operation including a temperature sensor for detecting the temperature of the inner pot, control means for executing rice cooking control by controlling the heating means of the inner pot according to the detected temperature of the temperature sensor, and a rice cooking switch for starting rice cooking With
The rice cooking control executed by the control means is
Including the water 1 step the detected temperature is kept at a predetermined time the temperature was increased to the first set temperature, and water 2 step the detected temperature rises at a small slope from the first predetermined temperature to a second set temperature A water absorption step for controlling the heating means,
A temperature raising step of controlling the heating means so that the detected temperature rises to about 100 ° C. with a gradient larger than the gradient in the water absorption two step ;
A boiling step in which the detected temperature is maintained at about 100 ° C .;
A cooking step of reducing the output of the heating means if the detected temperature suddenly rises from about 100 ° C. and reaches a predetermined temperature;
Wherein said control means performs on-off control of the heating means so as to increase the water 2 step the detected temperature is over a predetermined time period from the first predetermined temperature to the second set temperature stepwise in the Based on the integrated value of the ON time or OFF time of the heating means at a predetermined time, the rice cooking amount is determined from the relationship between the output of the heating means and the temperature rise gradient, and the heating amount in the subsequent process is determined as the rice cooking amount. The electric rice cooker characterized by adjusting based on quantity.

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