JPS6159725B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a heat-retaining electric rice cooker, and particularly to one that makes rice delicious after cooking.

It is known that the ideal method of cooking rice to make it delicious after cooking is to heat the rice at a relatively high temperature of around 100 degrees for about 15 to 20 minutes immediately after cooking to force the rice to become evenly distributed. There is. this is,
This is to prevent the surface of the rice from becoming sticky by completely absorbing the moisture attached to the outer peripheral wall of the rice grains into the rice grains by the time the rice is cooked and the rice is kept warm.
A relatively high temperature is required between the high temperature (150 to 160 degrees Celsius) before rice cooking is completed and the keeping temperature (70 degrees Celsius) when keeping the rice warm.

However, some rice cookers perform uneven work after rice cooking is completed before switching to the keeping warm state, but this is simply the process of changing from a high temperature (160 degrees) to a keeping temperature (70 degrees This refers to the period of time during which the temperature decreases until the temperature changes to 15°C, and the moisture is not completely absorbed into the rice grains due to the inability to achieve the optimal uniformity as described above, resulting in excessive moisture on the surface of the rice. This caused the surface to become sticky and the taste to be unpleasant.

Incidentally, in order to obtain the above-mentioned ideal uniformity, after the rice was cooked, an electronic circuit timer was used to heat the rice at a relatively high temperature for a certain period of time, but the timer was expensive and the wiring became complicated, and this method Electric rice cookers that reach such high temperatures have the disadvantage of causing malfunctions.

The present invention improves the various drawbacks mentioned above and provides ideal rice, and will be described below with reference to the drawings. 1 is a cylindrical frame; 2 is the frame 1;
A cylindrical outer pot with a bottom is attached with a heat insulating material 3 interposed therein, and 4 is a flat plate heating plate in which a rice cooking heater 5 is embedded, which is fixed to the inner bottom of the outer pot 2. Reference numeral 6 denotes a frame cover made of heat-resistant synthetic resin that fixes the upper peripheries of the outer pot 2 and the frame 1 at a certain interval, and 7 is located on the upper surface of the frame cover 6 and engages the frame cover 6 on one side. Place the other side in the outer pot 2
8 is a ring-shaped heat transfer plate that is engaged with the inner wall of the outer pot 2, and an inner pot that can be freely stored in the outer pot 2 with a predetermined interval ( ) on the side surface thereof; The lid body is supported and rotatable, and consists of the following inner lid, thermal insulation lid, and outer lid. Reference numeral 10 denotes an inner lid with good heat conduction, which has a knob 11 projecting upward in the center and is placed closely on the periphery of the opening of the inner pot 8;
2 is located on the upper surface of the inner lid 10, and the outer peripheral edge jumps over the mounting part on the outer periphery of the inner lid 10 to attach the heat exchanger plate 7.
13 is an outer lid made of synthetic resin with a heat insulating material 14 interposed therebetween, and is located on the upper surface of the insulation lid 12, and a pressure locking mechanism 15 is provided at the center of the back surface. ing. 16 is the heat insulation lid 12
An elastic press locking member made of silicone rubber or the like is provided in the center of the lid 12, and the lower end is flared to connect the outer pot 2.
When placed on the inner pot 8, its lower end periphery presses the upper surface of the inner lid 10 due to its own elasticity, bringing the outer periphery of the inner lid 10 into close contact with the inner pot 8. Reference numeral 17 denotes a side heater tightly wrapped around the entire circumference of the upper outer wall of the outer pot 2, and is composed of a heater 18 for uneven heating that generates a large amount of heat, and a heater 19 for keeping warm that generates a smaller amount of heat than the heater. 20 is a thermal reed switch (T/R/
With a temperature controller such as S), as shown in Figure 4, it is ON from room temperature to relatively low temperature [(T ₁ ) optimum temperature for keeping warm, around 70 degrees], and it is ON from constant temperature to relatively high temperature [T ₂ ) moisture. It is turned OFF until the temperature reaches around 100 degrees, at which temperature is vaporized, and thereafter it is turned ON again from this high temperature (T ₂ ), opening and closing built-in contacts (not shown). 21
is a rice-cooking thermostat that is energized so as to protrude upward from the constant heating plate 4 provided in the center of the heating plate 4, and the thermostat changes from room temperature to high temperature (160°C) when rice is completed.
degree), remains OFF when the temperature reaches a high temperature, and turns ON again when manually operated. 22 pivots an arbitrary part and connects one end to the frame 1
A switch lever 25 with a button 23 protruding further and connected at the other end to the rice-cooking thermostat 21 turns on the switch 24 by operating the button 23 and turns it OFF by operating the rice-cooking thermostat 21. Said frame 1
This is the camera back that covers the bottom of the camera.

Next, to explain the electric circuit diagram shown in FIG. 3, switch 2 of the rice cooking thermostat 21
4 is connected in series to the rice-cooking heater 5, is connected in parallel to the rice-cooking thermostat 21, and is composed of a series circuit of a heating heater 18 and a temperature regulator 20, and a heat-retaining heater 19 connected in parallel to this series circuit. and a heat insulation circuit 25 are connected thereto. 26 is a rice cooking operation indicator connected in parallel to the rice cooking heater 5, 27 is an unevenness and heat retention indicator connected in parallel to the rice cooking thermostat 21, and 28 is a temperature fuse.

Next, the operation will be explained with reference to FIGS. 3 to 5. The temperature characteristics of the outer surface of the outer pot 2 in an electric rice cooker over one hour are as shown in Fig. 5 (a), as it is heated only by the rice cooker heater 5 at the beginning of energization of the rice cooker 5, so the temperature rises rapidly and the rice cooks. When the rice reaches the maximum cooking completion temperature of 160 degrees, the rice cooking thermostat 21 turns off, and the temperature changes more rapidly than the temperature change during rice cooking, lowering the temperature to a relatively low temperature of about 70 degrees. It stabilizes around 30 degrees and then performs a heat-retaining operation. At this time, during the rice cooking operation, the temperature regulator 20 maintains the ON state in series at a relatively high temperature [(T ₂ ) around 100 degrees] for a predetermined period of time, and after the rice cooking is completed, the temperature controller 20 maintains the ON state at a relatively high temperature [(T _{2 )} around 100 degrees]. ) When the temperature drops to around 100 degrees, it turns OFF and then repeats the ON/OFF operation at around 70 degrees (T ₁ ). In the operation of the rice-cooking thermostat 21 and temperature controller 20 as described above, for example, the resistance value of the rice-cooking heater 5 is set to 16.7Ω, and the heat-retaining heater 19 is set to 16.7Ω.
Assuming that the resistance value of is 483.3Ω and the resistance value of the uneven heater 18 is 217.5Ω, during rice cooking, the rice cooking heater 5 heats the inner pot 8 with a calorific value of 600W to perform the rice cooking operation. When the maximum cooking temperature of rice reaches around 160 degrees, the rice cooking thermostat 21 is turned off, and a series circuit of the rice cooking heater 5 and the heat retention circuit 25 is formed. However, since the temperature controller 20 is turned on even after rice cooking is completed, the heat retention heater 19 outputs approximately 17W, the uneven heater 18 outputs 37W, and the rice cooking heater 5 outputs approximately 6W, resulting in a total output of approximately 60W. Inner pot 8 based on calorific value
In the process of heating the rice and lowering the temperature to around 100 degrees, which is a relatively high temperature when the temperature controller 20 is turned off, the temperature of the rice decreases to about 100 degrees from the time of completion of cooking, as shown in Figure 5 (b).
For 15 to 20 minutes, maintain a relatively high temperature around 100 degrees and perform forced unevenness. Eventually, when the temperature near the temperature controller 20 reaches a relatively high temperature of about 100 degrees after the above-mentioned 15 to 20 minutes of forced unevenness, the temperature controller 20 turns OFF and the unevenness heater 18 turns off. When the heat generation stops, a series circuit of the rice cooking heater 5 and the warming heater 19 is formed, and the rice cooking heater 5 outputs approximately 0.5W and the warming heater 19 outputs approximately 19.5W.
Shifts to heat retention operation at a total of 20W. At this time, in order to stop the heating of the uneven heater 18, which generates a large amount of heat, the rice temperature is lowered to the warming temperature in a short period of time, thereby preventing the rice from being exposed to higher temperatures than necessary and drying out before the warming operation is performed. That is, during the forced steaming, the rice is maintained at a high temperature for 15 to 20 minutes, so when the forced steaming is finished, it is necessary to lower the temperature to the keeping temperature in a short time. Then, by repeatedly turning the temperature regulator 20 ON and OFF, the rice cooking heater 5 and the heat retention and unevenness heaters 18 and 19 are turned on and off.
60W, rice cooking heater 5, and heat retention heater 19
Continuously maintains the optimal temperature of approximately 70 degrees at 20W. At this time, the heat retention state is set to ON when the temperature controller 20 is turned on.
-The uneven heater 18, which generates a large amount of heat, loses power when it is turned off, but the heat retention heater 19 continuously generates heat, resulting in a sudden temperature drop when the uneven heater 18 is turned off, and a sudden drop when the electricity is turned on. Prevents temperature rise and adversely affects rice temperature.

Thus, during the forced unevenness immediately after rice cooking as described above, the inner lid 10 and the heat-insulating lid 1
2, condensation occurs, but the water droplets (dew) evaporate at a relatively high temperature of about 100 degrees, preventing them from falling onto the rice, and also evaporating excess water that has formed on the surface of the rice, making it sticky. prevent.

As described above, the present invention heats the rice using a rice-cooking heater during rice cooking, and the temperature decreases from the high rice-cooking completion temperature at the time of rice cooking completion to a relatively low temperature keeping temperature. The rice temperature is forcibly maintained at a relatively high temperature of approximately 100 degrees for a predetermined period of time using a heating heater and a heat-retaining heater that generates less heat than the heating heater. This high-temperature heater is heated by cutting off the power to the uneven heater and generating heat from the heat-retaining heater. Due to the maintenance, dew generated during rice cooking and attached to the lid body evaporates and prevents it from falling onto the rice, and excess moisture attached to the surface of the rice is also evaporated to prevent stickiness. That is, this forced heating evaporates the water on the surface of the rice and at the same time absorbs the water into the grains of the rice, making the rice fluffy and delicious. Moreover, since the above-mentioned forced heating is performed by heating both the uneven heater and the heat-retaining heater, it can be easily performed without using a timer or the like. Furthermore, after the forced heating ends, the power is turned off to the uneven heater, which generates a large amount of heat, which prevents the rice from being heated more than necessary and becoming dry, and allows the rice to be kept warm in a short time. can. When keeping the food warm, the heat keeping heater continues to generate heat even if the power is turned off to the uneven heater, so the temperature change imparted to the rice is reduced and an ideal keeping temperature can be obtained.
In particular, complicated electrical connections are eliminated and the operation is performed with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the heat-retaining electric rice cooker of the present invention.
Figure 2 is a partial sectional view, Figure 3 is an electrical circuit diagram, and Figure 4 is a partial cross-sectional view.
The figure is an explanatory diagram of the operating temperature of the temperature regulator, and FIG. 5 is a temperature one-hour characteristic diagram of the temperature regulator and rice temperature, and the operating state of each part. 5... Heater for rice cooking, 19... Heater for keeping warm, 18... Heater for uneven heating.

Claims (1)

[Claims] 1 When cooking rice, heating is performed using a rice heater, and the temperature decreases from the high cooking completion temperature at the time of rice cooking completion to a relatively low temperature keeping temperature, and after rice cooking is completed, the heater for uneven heating is used. The temperature of the rice is forcibly maintained at a relatively high temperature of approximately 100 degrees for a predetermined period of time using a heat-retaining heater that generates less heat than the heating element, and the heating element is turned off after a predetermined period of time. A heat-retaining electric rice cooker, characterized in that the heat-retaining electric rice cooker is heated by the heat generated by the electric heat-retaining heater, and then the power is turned off to the uneven heater, and the heat-retaining heater continuously generates heat to maintain a warm state.