JPH0722541B2 - rice cooker - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rice cooker, and more particularly to control of a heating amount of a lid heater of the rice cooker.

[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 cooked rice, not only heating the inner kettle for storing rice from below,
It is said that the method of heating evenly from the top is effective, and the output of the lid heater, which was conventionally used only for keeping heat, was strengthened, and the rice cooking method of using the lid heater from above to cook rice was adopted. There is. 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 the point O, 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 the output of the bottom heater 4 is set to almost zero to enter the uneven state. After a lapse of a predetermined time in the stripping process, the body heater 6 is activated to enter the heat retaining state.

In the above rice cooking, the period from the switch being turned on to the boiling is referred to as a temperature rising period, and the period during boiling is referred to as a boiling period. These are the purging process and the heat retention process.

[Problems to be Solved by the Invention] By the way, in the above rice cooking process, the lid heater is operated together with the bottom heater to heat from the lower portion and the upper portion of the inner kettle. As a result, the surface of the cooked rice may be dried, and the components inside the lid may be deformed by the heat of the lid heater.

The present invention has been made to solve the above problems of the conventional rice cooker, and an object thereof is to provide a rice cooker that does not dry the surface of cooked rice and does not deform the parts of the lid.

[Means for Solving the Problems] The rice cooker according to the present invention sets the output of the lid heater together with the bottom heater to 100% at the start of rice cooking, and when the temperature detected by the temperature detecting means reaches the boiling point, A heating amount control means for reducing the output to a predetermined output is provided.

[Operation] In the present invention, when the temperature of the object to be heated in the inner kettle is boiled, the heating amount control means reduces the output of the lid heater, so that the surface of the cooked rice is not dried and the parts inside the lid are not dried. Will not be deformed.

[Embodiment of the Invention] FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a flow chart for explaining an operation relating to the present invention.
FIG. 3 is a diagram showing a heating curve and an output of the lid heater in cooked rice which is an embodiment of the present invention. The fourth
The same or corresponding parts as those described with reference to the drawings are designated by the same reference numerals and the description thereof will be omitted.

In the figure, 11 is a thermistor, 12 is an A / D converter for converting the signal from the thermistor 11 into a digital amount, and 13 is a microcomputer having the function of the heating amount control means of the present invention, for example, a microcomputer (hereinafter referred to as "microcomputer") At the start of rice cooking, the output of the bottom heater 4 and the lid heater 5 is set to 100%, and when it is confirmed that the temperature in the inner kettle 3 has reached the boiling point (100 ° C) through the thermistor 11, the lid heater 5 Reduce the output. The reduction of the output of the lid heater 5 is appropriately determined depending on the cooking condition, rice quality, and the like. A heater drive circuit 14 heats each heater based on a control signal from the microcomputer 13.

Next, the operation will be described based on the flowchart of FIG. When the rice cooker is powered on, the microcomputer 13 heats the bottom heater 4 and the lid heater 5 via the heater driving circuit 14 (S1, 2), and inputs a signal from the thermistor 11 It is determined whether the temperature in the kettle 3 has reached the boiling point (S3). Since the temperature is low at this point, the process waits in this step 3. When the temperature of the inner kettle 3 rises with time and reaches the point P (boiling point) as shown in FIG. 3, the microcomputer 13 selects step 4 in step 3, and the lid heater 5 Reduce the output. This output reduction is continued during the boiling period as shown in FIG.

As described above, according to the present invention, the output of the lid heater is set to 100% together with the bottom heater at the start of rice cooking, and the output of the lid heater is set to a predetermined value when the temperature in the inner kettle reaches the boiling point. Since the output is reduced, the surface of the cooked rice is not dried and the lid parts are not affected by overheating.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flow chart for explaining the operation relating to the present invention,
FIG. 3 is a diagram showing a heating curve and an output of a lid heater in cooking rice, which is an embodiment of the present invention, FIG. 4 is a partial sectional view of a rice cooker, and FIG. 5 is a case of cooking conventional rice. Is a heating curve of. In the figure, 3 is an inner kettle, 4 is a bottom heater, 5 is a lid heater, 11 is a thermistor, and 13 is a microcomputer. The same reference numerals in the drawings indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Masakazu Kobayashi 1728 Omaeda, Hanazono-cho, Oza-gun, Saitama 1 Mitsubishi Electric Home Equipment Co., Ltd. (72) Hiroshi Nakamura 1728 Omaeda, Hanazono-cho, Osato-gun, Saitama Prefecture 1 Within Mitsubishi Electric Home Equipment Co., Ltd. (56) Reference JP 62-133910 (JP, A) Actual opening 55-159019 (JP, U) Actual opening 48-93960 (JP, U)

Claims (1)

[Claims] 1. A rice cooker comprising a bottom heater disposed under the inner kettle, a lid heater disposed over the inner kettle, and temperature detecting means for detecting the temperature of the object to be heated. , At the start of rice cooking, the output of the lid heater is set to 100 with the bottom heater.
%, And the rice cooker is provided with heating amount control means for reducing the output of the lid heater to a predetermined output when the temperature detected by the temperature detection means reaches the boiling point.