JPH0429369B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a rice cooker that eliminates energy waste.

Conventional configuration and its problems It has been known that rice cookers can cook rice evenly and deliciously if the temperature distribution inside the pot is made uniform.

For this reason, conventional rice cookers have an inner pot inside the main body, a first heater on the outer bottom of the inner pot, a second heater on the outside of the inner pot, and a second heater inside the inner pot. The temperature distribution was made uniform.

However, although the second heater was very effective when the amount of rice to be cooked was large, it was of little use when the amount of rice to be cooked was small, and it was just a waste of electricity.

OBJECTS OF THE INVENTION In view of the above drawbacks, the present invention provides a rice cooker that does not consume unnecessary power.

Structure of the Invention In order to achieve this object, the rice cooker of the present invention includes a first heater provided on the inner bottom, a second heater provided on the inner surface, and a power supply to the second heater depending on the amount of rice to be cooked. In normal rice cooking, rice is cooked using the first heater and the second heater, but when the amount of rice to be cooked is less than a preset value, the control means controls the first heater and the second heater. Since only one heater is energized, wasted power is saved.

DESCRIPTION OF EMBODIMENTS A case where an embodiment of the present invention is used in an electronic jar rice cooker will be described below with reference to FIGS. 1, 2, and 3.

In FIG. 1, a protective case 4 is provided within a main body 3 to which a lid 2 having a lid heater 1 is attached so as to be openable and closable, and an inner pot 5 is provided within this protective case 4 in a detachable manner. The main body 3 is located at the bottom of the protective case 4.
A rice cooking switch 7 that operates in conjunction with an operation part 6 provided on the outer wall of
is provided, and the sides of the protective case 4 and the main body 3
A heat insulating material 9 is provided between them. Further, a temperature sensor 11 is provided on the side of the protective case 4 so as to come into contact with the heat retaining heater 10 and the inner pot 5.

In FIG. 2, the power source 12 is connected to one end of the lid heater 1, and the other end of the lid heater 1 is connected to a normally closed contact of a relay contact 13 connected to one end of the rice cooking heater 8. The other end of the rice cooking heater 8 is connected to one end of a warming heater 10, and the other end of the warming heater 10 is connected to the power source 12 via a triac 14. and microcomputer 15
(hereinafter referred to as the microcomputer 15) is connected to the power supply 12, and connects the relay coil 16 of the relay contact 13 and the triax 14 according to the signal from the temperature sensor 11.
make it work. Further, the normally closed contact of the rice cooking switch 7 connected to the power source 12 is connected to the microcomputer 15, and the normally open contact of the rice cooking switch 7 is connected to the contacts of the rice cooking heater 8 and the warming heater 10. In addition,
The triax 14 is operated by the output of the microcomputer 15, and the normally open contact of the relay contact 13 is connected to the power supply.

The operation will be explained below with reference to FIG.

When you operate the rice cooker switch 7 and connect C-NO, the microcomputer 15 detects this state and turns on the triax 14 and relay coil 16 over a certain period of time so that the temperature detected by the temperature sensor 11 becomes _T1 . By controlling rice cooking heater 8 and warming heater 1
Controls 0. This process is a pre-cooking process.

When the pre-cooking process is finished, the microcomputer 15
By continuously operating the triax 14 and the relay coil 16, the warming heater 10 and the rice cooking heater 8 are continuously operated. At this time, the temperature detected by the temperature sensor 11 increases in a quadratic curve. This process is a break-in process.

When the break-in process is completed, the temperature detected by the temperature sensor 11 increases with a constant slope. At this time, the microcomputer 15 calculates the slope between T ₂ and T ₃ and determines the amount of cooked rice in the inner pot 5 shown in FIG. If the amount of cooked rice is small, the slope will be large, and if the amount of rice cooked is large, the slope will be small. This step is a judgment step.

The rice cooking heater 8 and the heat retaining heater 10 are controlled by controlling the triax 14 and the relay coil 16 so that the temperature increase detected by the temperature sensor 11 is optimized according to the rice cooking amount determined in this way.
This process is a rice cooking process.

Next, as a result of determining the amount of rice to be cooked, if the amount of rice to be cooked is more than half of the maximum amount of rice to be cooked, the rice is cooked by the heat retention heater 10 and the rice cooking heater 8, and if the amount of rice to be cooked is less than half of the maximum amount of rice to be cooked, the rice is cooked by the temperature sensor 11. The detected temperature of
When the temperature reaches T ₄ (approximately 95°C), the triax 14 is made non-conductive, the heat retention heater 10 stops generating heat,
The rice is cooked only by the heat generated by the rice cooker heater 8. This process is a cooking process.

The cooking process continues until the water in the inner pot 3 shown in FIG. 7 switches from C-NO to C-NC. This signal is sent to the microcontroller 15
is detected, the relay coil 16 is made non-conductive, and the relay contact 13 is switched to C-NC. As a result,
The lid heater 1, the rice cooking heater 8, the warming heater 10, and the triax 14 are connected in series. Therefore, the temperature detected by the temperature sensor 11 is the predetermined set temperature T ₅
(approximately 73 degrees Celsius), the microcomputer 15 makes the triax 14 conductive, the lid heater 1, the rice cooking heater 8, and the warming heater 10 generate heat, and the detected temperature reaches _T5.
When it is higher than
4 is made non-conductive and does not generate heat.

As a result, the food to be cooked is kept at a constant temperature. The process immediately after the end of cooking is the uneven process.
After that, there is a heat retention process.

As described above, since the amount of rice to be cooked is determined based on the slope of temperature rise and the heater to be used in the rice cooking process is determined, unnecessary heating is not performed and power is not wasted.

In addition, the sticky bubbles that fill up in the pot during rice cooking will dry out and become wafer-like if the temperature at the top of the side of the pot is high. This will lower the temperature at the top of the side of the pot and prevent the bubbles from forming into a wafer.

Note that it goes without saying that the selection of the heater may be performed manually depending on the amount of rice to be cooked.

Effects of the Invention According to the present invention, as is clear from the above embodiments, when the amount of cooked rice is determined as a result of determining the amount of cooked rice, the heater attached to the upper part of the outer surface of the inner wall is not energized, resulting in extremely energy saving. becomes.

[Brief explanation of drawings]

FIG. 1 is a partially sectional side view of an electronic jar rice cooker which is an embodiment of the present invention, FIG. 2 is a circuit diagram of the same, and FIG.
The figure shows the temperature characteristics inside the inner pot. 2... Lid, 3... Main body, 5... Inner pot, 8... Rice cooking heater (first heater), 10... Warming heater (second heater), 15... Microcomputer (control means).

Claims (1)

[Claims] a main body, a lid provided on the main body opening so as to be openable and closable, an inner pot detachably provided inside the main body, and a first lid provided on the inner bottom of the main body so as to heat the outer bottom of the inner pot. A rice cooker comprising: a heater; a second heater provided on a side surface of the main body; and a control means for controlling energization of the second heater in accordance with the amount of rice cooked in the inner pot.