JPH0728816B2 - rice cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a heating method in which rice is cooked by a rice cooker without burning.

[Prior Art] Rice cookers, which heat and cook rice using electric power, have become widespread nationwide and have become an indispensable appliance in the kitchen of each household. For that reason, the enthusiasm of each manufacturer for developing the technology is wonderful, and it literally takes on the stance of day by day.

The biggest aim of development is how to cook rice into delicious rice, and for that reason, continuous development efforts are being made in every detail. Especially recently, in order to improve the taste of rice, not only heating the inner kettle for storing rice from below,
A method of evenly heating from above is effective, and therefore, the power of the lid heater, which was conventionally used mainly only for heat insulation, is strengthened, and the rice is heated by using the lid heater from above during rice cooking or muramurai. The method has been adopted. Therefore, the output of the lid heater has been increased from 10 watts in the past to 60 to 80 watts recently.

Fig. 4 is a sectional view of the rice cooker, in which 1 is an outer case and 2
Is a lid, 3 is an inner kettle, 4 is a bottom heater, 5 is a lid heater, 6 is a body heater, 7 is a radiator plate, 8 is an inner lid, 9 is rice, and 10 is water.

FIG. 5 is a heating curve in the case of cooking cooked rice using the above-mentioned cooker, and shows the time transition of cooked rice temperature. First, a predetermined amount of rice and water are stored in the inner kettle 3, and when the switch is turned on at 0 point, the bottom heater 4 and the lid heater 5 are turned on, and the rice and water are heated from the lower part and the upper part. The temperature of the rice and water in the inner kettle 3 rises in response to the heating, and when it reaches point P, it begins to boil. The temperature of the cooked rice maintains a boiling point of 100 ° C during boiling, but when the rice cooks and the water that evaporates at point Q disappears, the temperature of the cooked rice rises sharply as shown in the figure. The thermistor arranged in contact with the bottom of the inner kettle detects this rising temperature at the R point of 130 ° C., and sets the output of the bottom heater 4 to almost zero and enters the uneven state. In the purging process, the temperature of the cooked rice decreases as the heating by the heater becomes almost zero. Therefore, in order to prevent the cooked rice temperature from dropping, when the cooked rice temperature drops to the point S, the thermistor operates, and the bottom heater 4 is turned on again for a predetermined time t1 to raise the cooked rice temperature. In this way, so-called cooking is performed twice in the conventional purging process.

[Problems to be Solved by the Invention] By the way, when the rice is cooked twice in the unevenness process, heating is performed only by the bottom heater 4 from the bottom, so that the cooked rice in the inner kettle is uniformly heated when the amount of cooked rice varies. Not done. Of course, the rice cooker is equipped with a heating amount control means, and it is possible to adjust the heating amount to some extent, but if the amount of cooked rice is too small, it will be overheated and easily burned. Then, the temperature of cooked rice tends to be lowered, and the gelatinization tends to be insufficient, which has been a problem for some time.

The present invention has been made to solve the above problems,
It is an object of the present invention to provide a heating method in which the temperature of cooked rice above and below in the inner kettle is made uniform to prevent the occurrence of charring, and at the same time, the gelatinization is sufficiently performed.

[Means for Solving the Problems] A rice cooker according to the present invention includes a rice cooking amount calculation means for calculating the rice cooking amount of an object to be heated, and a heating device for setting a heating time of a lid heater in a spotting process according to the rice cooking amount. Both the time setting means and the bottom heater and the lid heater are heated at the start of rice cooking, and when the temperature detected by the temperature detecting means reaches the boiling point, the heating of the lid heater is stopped, and the detected temperature rapidly rises to a predetermined temperature. Occasionally, a heating amount control means for stopping the heating of the bottom heater and heating the lid heater for the set heating time is provided.

[Operation] Since the lid heater heats from the upper portion in the unevenness process and the heating time is controlled according to the amount of cooked rice, the most appropriate and uniform heating is performed according to the amount of cooked rice.
Therefore, the occurrence of charring is prevented, the gelatinization is sufficiently performed, and delicious cooked rice can be obtained.

[Embodiment of the Invention] FIG. 1 is a block diagram for explaining one embodiment of the present invention, FIG. 2 is a flow chart for explaining the operation thereof, and FIG. 3 is a diagram showing a heating curve of the present invention. is there. In addition,
The same or corresponding parts as those in the conventional example described in FIG.

In the figure, 21 is a thermistor provided at the bottom of the inner kettle 3, 22 is an A / D converter for converting the detected temperature (voltage value) of the thermistor 21 into a digital amount, and 23 is the rice cooking amount calculating means of the present invention, A microcomputer having the functions of heating time setting means and heating amount control means (hereinafter referred to as "microcomputer")
Then, the program created based on the flowchart shown in FIG. 2 is stored in the built-in ROM (not shown). The means for calculating the amount of cooked rice to be heated is obtained from the rate of rise Δθ / Δt of the cooked rice temperature in the course of the temperature rise of cooked rice, and the amount of cooked rice corresponding to the rate of rise is stored in the ROM as data. Has been done. Also,
The heating time of the lid heater 5 corresponding to the calculated rice cooking amount is also stored in the ROM as data. In addition,
A weight sensor may be provided at the bottom of the inner kettle 3 so that the amount of cooked rice can be detected. Reference numeral 24 is a timer, and 25 is a heater energizing circuit for energizing the bottom heater 4 and the lid heater 5 under the control of the microcomputer 23.

The operation of the rice cooker configured as described above will be described based on the flowchart of FIG. 2 with reference to the heating curve of FIG. When the switch is turned on at the point O, the microcomputer 23 passes through the heater energizing circuit 25 and the bottom and lid heaters 4, 5
Power is applied to each to start heating (S1, S2). Then, when the temperature reaches a predetermined temperature, the rate of temperature rise of the cooked rice is read from the thermistor 21, and the amount of cooked rice corresponding to the rate of rise is set, and the heating time of the lid heater 5 in the purging process is set.
Set t1 from the amount of cooked rice (S3, S4). Next, it is determined whether or not the temperature of the cooked rice in the inner kettle 3 has reached the boiling point (point P) (S5), and if the detected temperature has not reached the boiling point, the process waits in this step 5 and the temperature reaches the boiling point. When it reaches, the lid heater 5 is turned off (S6), and the process waits in step 7 until the detected temperature reaches 130 ° C. (point R). When it is confirmed in step 7 that the detected temperature has reached 130 ° C, the bottom heater 4 is turned off and the lid heater 5 is turned on again (S8, S
9), then activate the timer 24 to set the heating time t
It is determined whether it has reached 1 (S10). When the time measured by the timer 24 reaches the heating time t1, the lid heater 5 is turned off and the operation according to the present embodiment is finished (S11).

[Effects of the Invention] According to the present invention as described above, since the lid heater is heated for the heating time according to the amount of cooked rice when entering the purging process, the bottom part of the cooked rice is moved to the upper part in the purging process. Is heated on average, the phenomenon of burning at the bottom disappears,
Now you can get delicious rice.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining an embodiment of the present invention, FIG. 2 is a flow chart for explaining the operation thereof, FIG. 3 is a diagram showing a heating curve of the present invention, and FIG. 4 is a rice cooker. Fig. 5 is a partial cross-sectional view of Fig. 5, and Fig. 5 is a diagram showing a heating curve when cooking conventional cooked rice. In the figure, 3 is an inner kettle, 4 is a bottom heater, and 5 is a lid heater. The same reference numerals in the drawings indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Hiroshi Nakamura 1728 Omaeda, Omaeda, Hanazono-cho, Osato-gun, Saitama 1 Mitsubishi Electric Home Equipment Co., Ltd. (72) Masakazu Kobayashi 1728 Omaeda, Hanazono-cho, Osato-gun 1 Mitsubishi Electric Home Equipment Co., Ltd. (56) Reference JP-A-62-207411 (JP, A) JP-A-62-133910 (JP, A)

Claims (1)

[Claims] 1. A bottom heater disposed below the inner kettle, a lid heater disposed above the inner kettle, and temperature detection means for detecting the temperature of the object to be heated inside the inner kettle. In a rice cooker having a rice cooker, a cooked rice amount calculating means for calculating the cooked rice amount of the object to be heated, a heating time setting means for setting the heating time of the lid heater in the uneven distribution process according to the cooked rice amount, and a bottom at the start of cooking When both the heater and the lid heater are heated, the heating of the lid heater is stopped when the temperature detected by the temperature detecting means reaches the boiling point, and the heating of the bottom heater is stopped at the same time when the detected temperature rapidly rises to a predetermined temperature. And a heating amount control means for heating the lid heater during the set heating time, the rice cooker.