JPS5936524B2 - rice cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an automatic rice cooker that can cook delicious rice.

Generally speaking, in order to get delicious rice, it is best to cook it over high heat at first, and once the water inside the pot begins to boil, reduce the heat to a low level to prevent the rice from boiling over.

This is done by heating the rice inside the pot uniformly through convection at first over high heat, so that the entire rice absorbs moisture evenly, and the cooked rice is evenly cooked and deliciously cooked. Also, when the water in the pot starts to boil, the water in the pot will be absorbed by the rice and the rice will be reduced, and if you continue to heat it over high heat, it will break and burn.

In view of the above points, the present invention provides a relatively high amount of heat, and at the same time, the amount of heat given to the water in the pot is related to the temperature difference between the heating plate and the pot, and the heat transfer resistance between the two. Focusing on this, when the internal temperature of the pot reaches a temperature close to the boiling temperature of water, this temperature is sensed and the temperature of the heating plate is controlled.
This rice cooker has an automatic adjustment system that starts with high heat and then lowers the heat when it approaches boiling temperature.

The case where the present invention is implemented in an electric rice cooker will be explained below according to the drawings.

1 is a rice cooker main body having legs 2.

A heating plate 4 containing a built-in heater 3 as a heat source is located at the inner bottom of the main body 1.

5 and 6 are heat-responsive switches located so as to be freely retractable through a through hole formed in the center of the heating plate 4; one heat-responsive switch 5 is configured to operate at the rice cooking completion temperature, and the other heat-responsive switch 6 is configured to operate at the rice cooking completion temperature. is configured to operate at temperatures close to the boiling temperature of the

Note that these thermally responsive switches 5 and 6 are of a non-returnable type.

Reference numeral 7 denotes an automatic return type heat-responsive switch 7 that senses and responds to the temperature of the heating plate 4, and is disposed on the bottom surface of the heating plate 4 to keep the temperature of the heating plate constant. As is clear from FIG. 2, the thermally responsive switch 5, the heater 3, and the thermally responsive switch 7, which operate at the rice cooking completion temperature, are connected in series to the power source, and are connected in parallel to the thermally responsive switch 7.
A thermally responsive switch 6 operating at the boiling temperature of water is connected.

Reference numeral 8 denotes a control lever for the heat-responsive switches 5 and 6, and Al 9 represents a pot placed on the heating plate 4 in contact with the heat-responsive switches 5 and 6. Rice 10 and water 11 are stored in this pot. is cooked.

12 is the lid of the pot 9. The rice cooking operation of the present invention configured as described above is as follows.

Figure 3 shows the comparative performance of the temperature of the heating plate 4 and the bottom temperature of the pot 9 during rice cooking with the conventional example. 9 indicates the bottom temperature, the dotted line indicates the conventional example, ・O indicates the heating plate 4 temperature, (9 indicates the pot 9 temperature.

First, to explain the conventional example O and 0 curves, the heater 3 in the heating plate 4 normally has a power of about 600W at 1.81°C, and the temperature of the heating plate 4 is 01. C2,03
Like a dot, the water 11 and rice 10 in the pot 9 are heated by heat transfer and slowly rise.

Due to this temperature rise of the heating plate 4, water 11 and rice 10 in the pot 9
The temperature slowly rises from point A to point 90, and is about 10.
Maintain a constant temperature until it reaches 0℃ and water 11 disappears, and
When point 2 is reached and water 11 runs out, the temperature of pot 9 rises rapidly.
When the B3 point is reached, the heat-responsive switch is activated and rice cooking is completed.

At this time, the temperature of the heating plate 4 is constant due to the heat generated by the heater 3, and the amount of heat transferred from the heating plate 4 to the pot 9 is the temperature of the 0 curve.
It is determined by the temperature difference t3 of the 0 curve.

That is, after the temperature of the water 11 approaches approximately 100°C, t3
When the water 11 reaches a certain value or more, the water 11 reaches a boiling state, and a phenomenon of boiling over occurs, making it impossible to cook rice.

For example, if the heater 3 was set to a high power of 1000W, there would be a lot of boiling and boiling, and the rice could not be commercialized due to the loss of rice.

Further, since the amount of heat transferred from point A to point D□ was small, it was not possible to uniformly impart sufficient amount of heat to rice 10.

On the other hand, in the embodiment of the present invention, as shown in the curves ■ and ◎, the heater 3 is set to a relatively high wattage, for example, 1000 W, and the high heat amount due to tl is maintained until the temperature inside the pot 9 boils.
After it boils, it is designed to provide the appropriate amount of heat without boiling over or burning due to t2.

Place the pot 9, operate the lever 8, and turn on the heat-responsive switch 5,
6 is turned on, the heater 3 generates heat and the heating plate 4
The temperature rises as shown in the temperature curve, which causes the pot 9
The internal temperature rise becomes a zero curve.

The temperature inside the pot 9 is 30 points from point A, that is, almost boiling temperature 100℃
When the temperature is reached, the temperature at the bottom of the pot 9 is sensed and the heat-responsive switch 6 is turned on.
0FFJ.

At this time, the heat-responsive switch 7 that controls the temperature of the heating plate 4 is set at a temperature that does not cause boiling over and does not cause the rice to burn.
The temperature of the heating plate 4 is controlled according to a curve from point A3, which is lower than point A2, to point A4.

That is, in the temperature rising process, the rice is cooked with a high amount of heat due to to, and when it boils, the amount of heat due to the temperature difference t2 is used to cook the rice, and the water becomes 83 points from point B2, and the thermal response switch 5 changes to 10FFJ.
Complete L cooking.

According to an embodiment of the present invention, a high amount of heat is applied to the rice until the water boils, and the heating plate temperature is controlled while the water is boiling, thereby increasing the boiling time and producing delicious rice without boiling over or burning. It has the effect of cooking rice.

In addition, since the temperature of the heating plate can be controlled to a constant temperature when it boils, there is no risk of burnout of the main body, and there is also the effect of preventing wastage of electrical energy.

In addition, since the amount of heat generated is controlled by a heat-responsive switch, it can be manufactured at a lower cost than if multiple heaters are provided and switched.

According to the present invention, it is possible to automatically cook rice using high heat at first, and once the water inside the pot boils, low heat so that it does not sputter or burn. be.

[Brief explanation of drawings]

Figure 1 is a sectional view of the rice cooker of the present invention, Figure 2 is its wiring diagram,
FIG. 3 is a diagram comparing the temperature characteristics of the present invention and the conventional rice cooker. 4... Heating panel, 5, 6... Heat-responsive switch, 7... Heat-responsive switch, 9... Pot.

Claims (1)

[Claims] 1. A heat-responsive switch 5 is provided that senses the bottom temperature of the pot 9 placed on the heating plate 4 and turns off the power when rice cooking is completed, and also detects the internal boiling temperature of the pot 9 and turns the power off.
A thermally responsive switch 6 is further provided to control the temperature of the heating panel 4, and the thermally responsive switch 7 and the thermally responsive switch 6 that operates by sensing the boiling temperature are connected in parallel. This rice cooker is characterized by: