JPH064052B2 - Rice cooker - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rice cooker, and more particularly to a rice cooker that can stably cook porridge rice with simple rice cook control.

(Prior art) A rice cooker is a combination of an electric rice cooker and a heat retention jar. Generally, this rice cooker cooks rice by supplying heating power to a rice cooker provided at the bottom of the inner pot. The warming heater provided on the lid portion or the side portion is configured to keep warm after cooking rice.

In addition, by the program control by the controller equipped with a microcomputer, the water absorption process, the rice cooking capacity determination process, the cooking process, the boiling maintaining process, the first mudling process, the additional cooking process, the second muting process, the heat retention process, etc. A microcomputer-controlled rice cooker that controls the rice cooking process has been developed.

In this microcomputer-controlled rice cooker,
Since the control of the rice cooking process can be finely controlled by program control, it is possible to perform various functions such as multi-function rice cooking, fast rice cooking, timer reserved rice cooking, notification of when to eat, washing immediately after cooking by providing programs for multiple types of rice cooking control patterns. Those that can have and have these functions are being developed.

Furthermore, a rice cooker with the function of rice cooked is being developed. As a control method of this porridge rice, there is a method of controlling the heating power according to the time, and a method of judging the sum and heating with a large amount of power for a time corresponding to the sum and then lowering the power and heating for a predetermined time. It is known how to cook.

(Problems to be Solved by the Invention) However, in the case of controlling only for time, there is a problem that a difference in cooked state may occur due to fluctuations in the amount of cooked rice and electric power. That is, if the rice cooking time is set to the minimum amount, it will not cook when it is the maximum amount, and if it is set to the maximum amount, it will cook too much when it is the minimum amount. At high places, there is a problem of spilling and overcooking.

In addition, in the control method for judging the sum, the amount of rice for rice porridge is small, at most 2 to 2.5, and it is difficult to accurately judge even if the sum is judged. If there is an error in the summation judgment, it means that the spillage or cooking is not enough. In addition, if an attempt is made to accurately determine the sum, the sum determination program becomes complicated, a large-capacity program ROM is required, and the cost increases.

In view of the above conventional problems, the present invention, with a simple control program, does not spill over, does not cook enough, does not overcook, and is stable without being affected by fluctuations in power, etc. The purpose is to provide a rice cooker that can cook.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the rice cooker of the present invention comprises:
In a rice jar that allows you to select porridge rice, when porridge rice is selected, heat with high power until the cooking temperature reaches the boiling temperature after the water absorption step,
When the boiling temperature is first detected, the heating power is lowered, then the cooking temperature is detected and if the cooking temperature is lower than the boiling temperature, heating is performed with high power, and if it is higher than the boiling temperature, low power is used. By repeatedly performing heating with, the boiling temperature is maintained for a predetermined time from the time when the boiling is first detected, and when the predetermined time elapses, the boiling temperature is maintained by shifting to a muddling step. The present invention is characterized by comprising an uneven heating control means for performing the uneven heating control according to the heating control by the large current and the small current.

(Cooking) When rice cooked rice is set By running the rice cooked rice control program, it is heated with high power until the rice cooking temperature reaches the boiling temperature, regardless of the amount of rice cooked or fluctuations in power. You can cook to the boiling temperature in the shortest time.

When the rice cooking temperature reaches the boiling temperature, the heating power is lowered, and then the rice cooking temperature is detected.When the rice cooking temperature is below the boiling temperature, the rice is heated with high power, and when it is above the boiling temperature. The boiling temperature is maintained by repeating heating with a small amount of power for a predetermined time.During this time, depending on the conditions such as the amount of rice cooked, the outside air temperature, and fluctuations in power, the rate of temperature decrease during heating power reduction or low power heating, high power heating The rate of temperature rise changes with time, and this appears as a difference in the number of times of boiling, etc., but since the uneven heating control is performed according to the heating control state with a large current and a small current during such boiling, the amount of cooked rice Irrespective of fluctuations in electric power and electric power, without spilling, overcooking, or insufficient cooking, rather, it is possible to obtain a stable cooked porridge with a certain amount of treatment.

What's more, regardless of the amount of cooked rice, there is no need for a configuration that automatically determines this or sets it manually.
The configuration can be simple and inexpensive, and failure to cook rice due to erroneous determination or erroneous operation can be avoided.

(Example) FIG. 10: has shown the 1st Example of this invention. But,
The inventors of the present invention first conceived the reference examples shown in FIGS. 1 to 9 with respect to the above problems, and then arrived at the present invention.

To facilitate understanding, this reference example will be described first.

In FIG. 1, 1 is a rice cooker body, 2 is a lid portion of the rice cooker body 1, and 3 is a body portion of the rice cooker body. In the body part 3,
Inner pot 4, inner pot container 5 for storing inner pot 4, rice heater 6 provided at the bottom of inner pot container 5, temperature sensor 7 provided so as to contact the bottom of inner pot 4, inner pot storage Container 5
A side heat insulation heater 9 provided on the side of the device, a control unit 10 incorporating a microcomputer and the like are provided inside. The lid 2 is provided with a lid warming heater 8.

Reference numeral 11 denotes a function display selection operation unit, which is arranged at an upper position of the rice cooker book 1. As shown in FIG. 2, the function display selection operation unit 11 is provided with a character display 12, various key switches 13 (13a to 13f), light emitting diodes 14 (14a to 14e) for displaying various states, and the like. There is. The character display 12 is composed of a 4-digit numerical display liquid crystal module that displays the characters of each display digit in 7 segments, and displays the time, the reserved time when reserved rice is cooked, and the like. 13a is a key switch for operating the time digit,
13b is a minute key switch operated by a minute digit, 13c is a reservation key switch for instructing reservation, 13d is a menu key switch for instructing a rice cooking menu, 13e is a start key switch for instructing a rice cooking operation start or a reserved rice cooking operation start, 13f Is a cancel key switch for instructing cancellation of each operation. 14a and 14b set the reservation mode to "reservation 1",
In order to distinguish "Reservation 2", 14c, 14d, and 14e are light emitting diodes that display the respective states by distinguishing the rice cooking menu type and the heat retention mode of rice cooking control. In the rice cooker of this embodiment, as is apparent from the panel surface in FIG. 2, the rice cooking menu is limited to "white rice" and "porridge", and the rice cooking control program is simplified to reduce the cost of the product. .

FIG. 3 is a block diagram showing a configuration of a main part of the control unit 10. In FIG. 3, 15 is a commercial AC power supply, and 16
Is a thermal fuse. The control unit 10 includes a switching relay 17, a triac 18 for controlling energization of the rice cooking heater 6, a triac 19 for controlling energization of the heat retaining heaters (the lid heat retaining heater 8 and the side heat retaining heater 9), a microcomputer 20, a clock mechanism. 21 and a buzzer 22 are provided. The temperature sensor 7 is composed of a thermistor or the like, and the detection signal thereof is the microcomputer 2
0 is input to the analog / digital conversion port.

The microcomputer 20 includes a processing device CPU,
A memory RAM, a program memory ROM, an input port having an analog / digital conversion function, a plurality of input port control output signals for receiving a key switch input, an output port for outputting a display control signal, and the like are built-in. According to the stored program, a predetermined output signal is output from the output port in response to the input from the input port. That is, the microcomputer 20 receives inputs from the temperature sensor 7, the timepiece mechanism 21, and the operation key switch 13, performs a series of processes according to a processing program incorporated therein, and controls the triacs 18 and 19 for controlling the energization of the heater. In addition to sending a signal, a lighting control signal to the light emitting diode 14 is sent in order to display a state such as an operation mode. In addition, the clock mechanism 2
The time signal from 1 is input, the time and time are displayed on the character display 12, and the time signal is used as a signal for determining the reserved time when the timer reserved rice is cooked.

FIG. 4 is a flowchart showing an outline of the flow of overall control of the microcomputer 20.

When the power is turned on, the rice cooking control preprocessing is performed in step 31. In this rice cooking control preprocessing, initialization processing for resetting various internal registers, timers, etc. of the microcomputer 20 is performed, and rice cooking operation instruction data setting processing such as rice cooking menu setting, rice cooking reservation time setting, etc. is performed, and subsequently started. When the key switch 13e is turned on, or when the reserved time comes in the case of reserved rice cooking, the processing from step 32 is performed. In step 32, the relay 17 is turned on and the circuit of the rice cooking heater 6 is turned on in order to control rice cooking. Next, the rice cooking process control of step 33 is performed. As a result, a rice cooking operation for cooking rice is performed. When the rice cooking operation is completed, in step 34, the relay 17 is turned off to turn off the circuit of the rice cooking heater 6 to perform heat retention control in a heat retention control mode to keep the cooked rice warm. In the heat retention control mode, the processing from step 35 is performed.

In this heat retention control mode, normal heat retention control is performed in step 35, and it is determined in the next step 36 whether or not the temperature is abnormal. If the temperature is abnormal, step 37
Error processing such as error notification and error display,
The whole process is ended. If the temperature is not abnormal, the process returns to step 35 to repeat the normal heat retention control.

Next, the operation of rice cooking control by the microcomputer control will be described.

When a predetermined amount of rice and water corresponding thereto are put in the inner pot 4 and the start key switch 13e is turned on, the microcomputer 20 follows the processing steps of the rice cooking program stored in the program memory ROM for heating in the rice cooking process. Start the power control of. At this time, the microcomputer 20 converts the output voltage from the temperature sensor 7 into a digital amount from the input port A / D, inputs the converted voltage, performs conversion processing to the temperature, judges the input temperature, and judges the judgment result. Controls various rice cooking processes.

To explain the outline of this rice cooking process, in the early stage of rice cooking, a water absorption process is performed in which the heating power is reduced and the rice absorbs water. Next, a heating step is performed in which the heating power is maximized and the temperature is rapidly raised to bring it to a boil, and then a boiling maintaining step in which the boiling is continued is performed. When this boiling maintaining step continues and the rice has sufficiently absorbed water and there is no water in the bottom of the inner pot, reaching a predetermined temperature, for example, 130 ° C., this temperature is detected and the rice cooking heater 6 is turned off to maintain the boiling maintaining step. To finish. Next, during a predetermined time, the first spotting process, the first additional cooking process, the second stripping process, the second additional cooking process, etc. are performed, and the rice cooking process is completed. Then, the heat retention step is finally reached.

FIG. 5 shows a rice cooking temperature curve showing a temperature change of the inner pot when the above normal rice cooking process is controlled. Region I
Indicates a water absorption process, region II indicates a cooking process, region III indicates a boiling maintaining process, and region IV indicates a purging process including a reheating process. The cooking process of region II is a process of increasing the heating power to rapidly raise the temperature to bring it to the boil and continue to the boiling maintaining process, and this process includes a process of determining the rice cooking capacity (sum number determination). . And in the next boiling maintenance step,
The cooking power is controlled to an appropriate heating power according to the determined cooking capacity, and boiling is appropriately maintained to cook the rice.

FIG. 6 is a flowchart showing the control operation in the rice porridge control. When porridge cooked rice is selected as the cooked rice menu and the start key switch 13e is turned on to start porridge cooked rice control, first, in step 40, the water absorption process is performed. This is a process of warming the water a little for a predetermined time by timer control so that the rice absorbs the water sufficiently. Upon completion of the water absorption process, in step 41, the rice-cooking heater 6 is fully energized so as to reach the maximum power and heated with a large amount of power to boil in the shortest time regardless of fluctuations in the rice-cooking amount and power. Make it ready to cook. Next, at step 42, it is judged whether the temperature is lower than 100 ° C. When the cooked rice temperature is lower than 100 ° C., that is, lower than the boiling temperature, the boiling temperature has not been reached and the cooking has not been completed. Therefore, the process returns to step 41, and the rice heater 6 is continuously energized. In this way, the rice is cooked without making the total number determination which is performed by the normal rice cooking control. When the temperature is 100 ° C. or higher, the process proceeds to step 43, and it is determined whether the timer set flag F is 1 or not.
If it is not 1, the routine proceeds to step 44, where the timer is set and the timer set flag F is set to 1, and then the routine proceeds to step 45. 100 ° C in step 45
If it is determined that the temperature is lower than 100 ° C., the process returns to step 41 and the rice cooking heater 6 is fully energized, that is, a large amount of power is energized to quickly heat the rice cooking heater 6 to 100 ° C.
If the temperature is equal to or higher than 0 ° C., the process proceeds to steps 46 and 47, and the heating power is reduced to energize the small electric power to continue the heating. Here, heating is performed, for example, by turning on the 800 W rice cooking heater 6 at 02/14 and turning on the 50 W warming heaters 8 and 9 at 12/14. Next, at step 48, it is judged whether the timer clock has elapsed t seconds (for example, 1600 seconds).
If t seconds have not elapsed, the process returns to step 45, and the operations between steps 45 and 48 are repeated. In this way, after detecting 100 ° C in the cooking process, heating is performed with high power when the temperature is higher than the boiling temperature so as to maintain the boiling temperature of 100 ° C for t seconds, and with low power when the temperature is lower than the boiling temperature. The heating control is performed so as to heat by heating. In addition, in the middle of returning from step 48 to step 45, at step 49, 130 ° C.
It is judged whether or not it is below, and if it exceeds 130 ° C, t
Since the water is exhausted before the elapse of seconds, the process immediately proceeds to step 50. When t seconds have elapsed in the determination in step 48, the timer set flag is set to 0 in step 50, the porridge cooking rice control process is terminated, and the process shifts to the mulling process.

In this way, in the rice porridge control, rice is cooked at full power without judging the rice cooking capacity (judgment judgment), and after boiling temperature is detected and cooking is completed, heating power is detected based on temperature detection. The boiling temperature is maintained by appropriately switching between full energization and reduced electric power, and by continuing this boiling state for a predetermined time, it is possible to constantly obtain a stable porridge.

FIG. 7 to FIG. 9 show the temperature change when such porridge rice cooking control is performed in comparison with the case where the heating condition is controlled only by time.

FIG. 7 shows the case of cooking rice cooked with porridge of 1 go.
(a) shows a reference example of the present invention, and (b) shows an example of heating control only for time (hereinafter, abbreviated as time control). Fig. 7
As shown in (a), in the reference example of the present invention, full energization is stopped after detecting the cooking end state based on the detection of the boiling temperature, and then the boiling state is maintained for a certain time t. . In this way, the porridge with a predetermined cooked state can be obtained. On the other hand, in the time control, as shown in FIG. 7 (b), full energization is performed for a predetermined time t ₁ and then low power energization is performed for a predetermined time t ₂ (for example, a rice cooker heater 02/14, a heat retention heater
However, in this case, the boiling time s is shorter than t, and the state is slightly insufficient.

FIGS. 8 (a) and 8 (b) show the case where 0.5 rice is cooked in porridge. In the reference example of the present invention, as shown in FIG. 8 (a), after full energization for a relatively short time until the cooking end state,
Since the boiling state is maintained for a certain time t, it is possible to obtain porridge in a predetermined cooked state even with a small capacity. On the other hand, in the time control, as shown in FIG. 8 (b), the boiling state is reached during the full energization time t ₁ , the boiling time s is lengthened, and the overcooked porridge is obtained.

Fig.9 (a), (b) shows 1 when the power source power is reduced to 90V.
The case of cooking rice with rice is shown. In the reference example of the present invention, as shown in FIG. 9 (a), after full energization for a relatively long time until the cooking end state, the boiling state is maintained for a certain time t, so the supplied power is Even when the temperature becomes low, porridge with a predetermined cooked state can be obtained. On the other hand, in the time control, as shown in FIG. 9 (b), the full energization time t
Even after ₁ has passed, the boiling state does not occur, the boiling time s is shortened, and porridge with insufficient cooking is obtained.

However, in the heating control as in the above reference example, the result of the cooked rice sometimes changed due to the difference in the amount of cooked rice, the outside temperature, or the difference in the power supply voltage.

The present invention has also dealt with this, and FIG. 10 is a flowchart showing the heating control state in the case of porridge rice in one embodiment of the present invention.

Since the structure and control mechanism of the rice cooker for executing this and the control other than the porridge rice cooker control are the same as those of the above-mentioned reference example, the drawings and description of the reference example are cited and the description thereof is omitted here.

In FIG. 10 showing the flow chart of the porridge rice cooking control operation, first, in step 60, a water absorption process is performed. When the process of the water absorption step is completed, the rice cooking heater 6 is fully energized in step 61. Next, at step 62, it is judged whether the temperature is 95 ° C. or lower. When the temperature is 95 ° C. or lower, the state in which the rice can be cooked is not ready, so the process returns to step 61, and the rice cooking heater 6 is continuously energized. If the temperature is 95 ° C. or higher, the process proceeds to steps 63 and 64 to reduce the heating power and continue heating. Here, for example, the 800W rice cooking heater 6 is turned on at 02/14, and the 50W heat retaining heater 8 is
Heat to turn 9 on 12/14. Next, step 6
After setting timer T ₁ in step 5, in step 66 95 ° C
It is determined whether or not the following. If the temperature is 95 ° C. or lower, the timer T ₁ is reset in step 67, the clock is restarted, the process returns to step 61, and the rice cooking heater 6 is fully energized and heated. If the temperature exceeds 95 ° C,
In step 68, the timer T ₁ is set to t seconds (for example, 1
It is determined whether or not (600 seconds) has elapsed. If t seconds have not elapsed, the process returns to step 63 and the operation during that period is repeated. In this way, heating control is performed so that the state of 95 ° C. or higher continues for t seconds in the cooking process. In addition,
Step 6 on the way from step 68 to step 63
It is judged in step 9 whether the temperature is 130 ° C. or lower. If the temperature is higher than 130 ° C., the water content is exhausted before t seconds have elapsed, and therefore the process immediately proceeds to step 72. In step 70, it is determined whether the temperature is lower than 100 ° C, and the temperature is 100 ° C.
In the above boiling state, the time counter T ₂ is counted in step 71, the process returns to step 63, and the time in the boiling state is measured. Step 68
When t seconds have elapsed in the determination of No. or 130 ° C. or higher in the determination of Step 69, the heater is turned off in Step 72, the porridge rice cooking control process is terminated, and the process shifts to the next Murashi process. Time counter T in steps 73 and 74
_The time in the boiling state is determined depending on whether the value of ₂ is 120 or less, or greater than 120 to 180 or 180, and in steps 75, 76 and 77, the unevenness time corresponding to the boiling time is 15 minutes, 10 15 minutes each for 7 minutes:
00, 10:00, and 7:00 respectively, and then, in step 78, the time display is sequentially subtracted for each elapsed time, and the process proceeds to step 79 to determine whether the time display has become 0:00. If it is not 0:00, the process returns to step 78 and waits until 0:00, and when it is 0:00, the process proceeds to step 80, and a buzzer is informed that the purging has ended.

In short, according to the heating control of rice cooked rice shown in the above embodiment, by heating the rice cooked rice control program when rice cooked rice is set, the rice is heated with a large amount of power until the rice cooking temperature reaches the boiling temperature. This makes it possible to cook to the boiling temperature in the shortest time regardless of the amount of cooked rice and the fluctuation of electric power.

When the rice cooking temperature reaches the boiling temperature, the heating power is lowered, and then the rice cooking temperature is detected.When the rice cooking temperature is below the boiling temperature, the rice is heated with high power, and when it is above the boiling temperature. The boiling temperature is maintained by repeating heating with a small amount of power for a predetermined time.During this time, depending on the conditions such as the amount of rice cooked, the outside air temperature, and fluctuations in power, the rate of temperature decrease during heating power reduction or low power heating, high power heating The rate of temperature rise changes with time, and this appears as a difference in the number of times of boiling, etc., but since the uneven heating control is performed according to the heating control state with a large current and a small current during such boiling, the amount of cooked rice Regardless of fluctuations in electric power, electric power, outside temperature, etc., it is possible to stably obtain porridge with a certain amount of cooked state without spilling, overcooking, or insufficient cooking.

Moreover, since the amount of cooked rice does not matter, there is no need to automatically judge this or to set manually, and the configuration can be simple and inexpensive, and the rice cooked based on erroneous judgments and erroneous operations can be cooked. Failures can also be avoided.

(Effect of the invention) According to the rice cooker of the present invention, by heating with high power until the rice cooking temperature reaches the boiling temperature, the boiling temperature can be reached in the shortest time regardless of the amount of cooked rice or fluctuations in the power. You can cook it.

Further, when the rice cooking temperature reaches the boiling temperature, the heating power is reduced, so that it is possible to prevent overshoot of the rice cooking temperature and save power.

Then, after this, the rice cooking temperature is detected, and when it is below the boiling temperature, it is heated with high power, and when it is above the boiling temperature, it is heated with low power, and the boiling temperature is repeated for a predetermined time. In addition to the above, the uneven heating control is performed according to the heating control state by the large current and the small current, which varies depending on the conditions such as the amount of cooked rice, the outside temperature, and the power fluctuation during this period. Irrespective of the outside temperature and the like, it is possible to stably obtain porridge with a certain amount of cooked state, including spilling, without spilling, overcooking, or insufficient cooking.

Moreover, since the amount of cooked rice does not matter, there is no need to automatically judge this or to set it manually, and only boiling temperature detection, heating power control, and timer control are required. For example, a small-capacity program ROM can be used to make it simple and inexpensive, and failure to cook rice due to erroneous determination or erroneous operation can be avoided.

[Brief description of drawings]

FIG. 1 is a partially cutaway sectional view of a rice cooker according to a reference example of the present invention, FIG. 2 is a front view of a panel surface of a function selection operation unit, and FIG. 3 is a block diagram showing a configuration of a control unit. FIG. 4 is a flowchart showing the overall flow of control, FIG. 5 is a diagram showing an example of a rice cooking temperature curve when normal rice cooking control is performed, and FIG. 6 is a flowchart showing the flow of control operations in porridge rice control. , FIG. 7 to FIG. 9 show rice cooking temperature curves when rice porridge rice control is performed under various conditions, and each figure (a) is a rice cooking temperature curve in a reference example of the present invention, the same figure (b). Shows a rice cooking temperature curve when controlled only by time, and FIG. 10 is a flowchart showing a flow of control operation in porridge rice cooking control in the embodiment of the present invention. 6 ………… Rice cooker 7 ………… Temperature sensor 8 ………… Holder heater 9 ………… Heat heater 10 ………… Control unit 20 ………… Microcomputer 21 ………… … Clock mechanism

Claims (1)

[Claims] 1. In a rice cooker capable of selecting porridge rice, when porridge rice is selected, after the water absorption step, it is heated with high power until the cooking temperature reaches the boiling temperature, and the boiling temperature is first set. When the rice cooking temperature is lower than the boiling temperature, it is heated with a large amount of electric power, and when it is higher than the boiling temperature, it is heated with a small amount of electric power. By repeating
The boiling temperature is maintained for a predetermined time from the time when the boiling is first detected, and when the predetermined time elapses, the heating control is performed by a large current and a small current that shifts to the muddling step to maintain the boiling temperature. A rice cooker characterized by being provided with uneven heating control means for controlling uneven heating.