JPH03212231A - electric rice cooker - Google Patents

Abstract

PURPOSE:To prevent dew condensation on the inner side of a lid and enable the thermal insulation of a cooked material without causing any deterioration of the taste, shape or the like thereof by supplying power at a constant rate to a lid heater during the time of a process immediately after a thermal insulation process to the drop of pot temperature to thermal insulation temperature, and interrupting a constant rate of power supply to low temperature, barrel and lid heaters, when the pot temperature further drops below the thermal insulation temperature. CONSTITUTION:A control means 10, upon receipt of a signal from a pot temperature detection means 9, controls a lid heater drive means 8 during the time of the start of a thermal insulation process immediately after a cooking process to the drop of the temperature of a pot 1 to or below thermal insulation temperature, and supplies power to a lid heater 5 at a specified rate. When the temperature of the pot 1 further drops below the thermal insulation, the control means 10 controls a bottom heater drive means 6, a barrel heater drive means 7 and a lid heater drive means 8, respectively for supplying power to the bottom, barrel and lid heaters 2, 3 and 5 at a specified rate or for interrupting the power supply thereto so as to keep the temperature of the pot 1 at the thermal insulation temperature. According to the aforesaid construction, dew condensation on the inner side of a lid 4 can be prevented during the thermal insulation process, and a cooked material can be thermally insulated without any deterioration of taste, shape or the like thereof due to the falling of dew drops.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an electric rice cooker having a heat retention function.

BACKGROUND OF THE INVENTION In recent years, there has been a demand for electric rice cookers with a heat retention function that can keep rice warm without impairing the taste of the rice.

A conventional electric rice cooker of this type will be explained with reference to FIG. 10. As shown in the figure, a pot 21 is used for cooking rice.The bottom portion of the pot 21 is heated by a bottom heater 22, and the side portion is heated by a rice cooker heater 23.

Further, the pot 21 is closed with a lid 24. The bottom heater drive means 26 energizes the bottom heater 22 , and the body heater drive means 26 energizes the body heater 23 . The pot temperature detection means 27 detects the temperature of the pot 21 and controls its output to the control means 28.
Enter. The control means 28 controls the bottom heater drive means 25 and the body heater drive means 26 so that the temperature of the pot 21 becomes the heat retention temperature in the heat retention process.

Next, the operation of this conventional example will be explained according to FIG. 11. In step 30, the heat retention process is entered, and then in step 31, the control means 28 inputs the signal from the pot temperature detection means 27, and the temperature θ of the pot 21 is determined as the heat retention temperature θ = 71
．． It is determined whether the temperature is higher than 5° C., and if it is higher, a signal is output to the bottom heater drive means 25 and the body heater drive means 26 to turn off the electricity to the bottom heater 22 and the body heater 23. On the other hand, when the temperature is low, 1/16 is applied to the bottom heater 22, and 1/16 is applied to the body heater 23.
It was kept warm by applying electricity at an energization rate of /16.

Problems to be Solved by the Invention In such a conventional electric rice cooker, the bottom heater 22 and the body heater 23 are not energized during the period from the rice cooking process to the heat retention process until the temperature of the pot 21 becomes lower than the retention IML temperature. As the water stops, the inside of the lid 24 and the sides of the pot 21 cool down, dew forms on the inside of the lid 24 and the sides of the pot 21, and the dew falls on the rice to cook, causing the rice to absorb moisture. There was a problem that it contained a lot of water, causing it to lose its shape, become white, and taste bad.

5. The present invention solves the above-mentioned problem, and prevents dew from forming on the inside of the lid and keeps the rice warm without deteriorating the taste, shape, etc. of the cooked rice due to the dew falling onto the rice. This is the first purpose. In addition to the first purpose, the second purpose is to prevent abnormal heating of the lid heater and increase the durability of the lid heater. In addition to the first purpose, the third purpose is to prevent dew from forming on the inside of the side part of the pot, so that dew does not fall onto the cooked rice and deteriorate the taste and shape of the cooked rice. It's about keeping warm.

Means for Solving the Problems In order to achieve the above-mentioned first object, the present invention inputs a signal from the pot temperature detection means to the control means, and the control means adjusts the temperature of the pot immediately after entering the warming step from the rice cooking step. The lid heater drive means is controlled to energize the lid heater at a constant energization rate until the temperature of the pot falls below the keep-warm temperature, and when the temperature of the pot falls below the keep-warm temperature, the bottom heater drive means, body heater drive means, and lid heater The driving means is controlled so that the bottom heater, the body heater, and the lid heater each have a constant flow of 6 bays so that the temperature of the pot becomes the insulating temperature.

The first means to solve the problem is to control the power supply so that the power supply is turned on or off at a certain rate.

In order to achieve the second objective, in addition to the first problem solving means, signals from the lid temperature detection means and the pot temperature detection means are input to the control means, and the control means changes from the rice cooking process to the warming process. Immediately after the pot is put in the pot until the temperature of the pot falls below the heat retention temperature, the lid heater driving means is controlled to either energize the lid heater at a constant energization rate or stop energizing it so that the temperature of the lid remains at a constant temperature. When the temperature of the pot falls below the keep-warm temperature, the bottom heater drive means, the body heater drive means, and the lid heater drive means are controlled, and the bottom heater, body heater, and lid heater are each controlled at a constant level so that the temperature of the pot becomes the keep-warm temperature. The second means for solving the problem is to control the power supply so that the power supply is energized or stopped at the energization rate. In order to achieve the third objective, in addition to the second problem-solving means described above, the body heater drive means is used during the period from immediately after the rice cooking process to the warming process until the temperature of the pot becomes below the warming temperature. A body heater 7 controls the lid heater drive means so that the temperature of the lid is constant.

The third means for solving the problem is to energize the lid heater and the lid heater at a constant energization rate, or to stop energizing them.

Effect of the Invention According to the first problem-solving means described above, the lid heater is energized for a period when the temperature of the pot is below the heat retention temperature immediately after the rice cooking process enters the heat retention process to heat the lid and close the lid. It is possible to prevent the inside of the pot from getting cold and dew forming, and when the temperature of the pot falls below the keep-warm temperature, the power supply to the bottom heater, body heater, and lid heater can be controlled to keep the temperature of the pot at the keep-warm temperature.

In addition, according to the second problem solving means, the lid heater is set at a constant temperature so that the temperature of the lid remains constant during the period from immediately after entering the warming process from the rice cooking process until the temperature of the pot falls below the warming temperature. It is possible to prevent dew from forming on the inside of the lid and also to prevent abnormal heating by energizing at the energization rate or stopping the energization.

Furthermore, according to the third problem solving means, the body heater and the lid heater are set so that the temperature of the lid is kept constant during the period from immediately after the rice cooking process to the warming process until the temperature of the pot falls below the warming temperature. It is possible to prevent dew from forming on the inside of the lid and the sides of the pot by energizing at a certain energization rate or stopping the energization.

Example An embodiment of the first invention will be described below.

In Figure 1, pot 1 is used for cooking rice.
The bottom part of this pot 1 is heated by a bottom heater 2, and the side part is heated by a body heater 3. Further, the pot 1 is closed by a lid 4, and the lid 4 is heated by a lid heater 6. The bottom heater drive means 6 energizes the bottom heater 2 , and the body heater drive means 7 energizes the body heater 3 . Further, the lid heater driving means 8 energizes the lid heater 5 . Pot temperature detection means 9
detects the temperature of pot 1. The control means 1o inputs the signal from the pot temperature detection means 9, and controls the lid heater driving means 8 during the period from immediately after the rice cooking process to the keeping-warm process until the temperature of the pot 1 becomes below the keep-warming temperature. 5 is energized at a constant energization rate, and when the temperature of the pot 1 falls below the heat retention temperature, the bottom heater drive means 6, the body heater drive means 7, and the lid heater drive means 8 are activated.
The bottom heater 2, the body heater 3, and the lid heater 5 are controlled to be energized at a constant energization rate or stopped to be energized so that the temperature of the pot 9 page 1 becomes the heat retention temperature.

Next, FIG. 2 is a specific circuit diagram, in which the bottom heater driving means 6 is composed of a relay contact 6a, a relay coil eb, a transistor 6c, and a resistor 6d.

One side of the relay contact 6a is connected to the AC power source 11, and the other side is connected to the bottom heater 2. One side of the relay coil 6b is connected to the DC power supply 12, and the other side is connected to the collector of the transistor 6c. The emitter of the transistor 6c is connected to the ground, and the conductor is connected to the resistor 6d and the output of the control means (hereinafter referred to as microcomputer) 1o. The body heater driving means 7 includes a bidirectional three-terminal control element (hereinafter referred to as a thyristor) 7a and a resistor 7b.

It is composed of a transistor 7c and a resistor 7d. The T1 terminal of the thyristor 7a resists the AC power supply 11 and
The two terminals are connected to one side of the body heater 3, and the gate terminal is connected to one side of the resistor 7b.

The other side of the resistor 7b is connected to the contact terminal of the transistor 7c, the emitter of the transistor 7c is connected to the ground, and the conductor of the transistor 7c and one side of the resistor 7d are connected to the output of the microcomputer 10.

The lid heater driving means 8 is composed of a thyristor 8a, a resistor 8b, a transistor 8c, and a resistor 8d. The T1 terminal of the thyristor 8a is connected to the AC power supply 11, the T2 terminal is connected to one side of the lid heater 5, and the gate terminal is connected to one side of the resistor 8b. The other side of the resistor 8b is connected to the collector of the transistor 8c, the emitter of the transistor 8c is connected to ground, and the pace of the transistor 8c and one side of the resistor 8d are connected to the output of the microcomputer 10. The pot temperature detection means 9 is a thermistor 9a,
It is composed of a resistor 9b, an A/D converter 9c, and resistors 9d and 9e. pA/D by thermistor 9a and resistor 9b
A voltage corresponding to the pot temperature is input to the converter 9c. Resistance 9d.

A reference voltage for A/D conversion is inputted to the A/D converter 9C by 9e. Further, the output of the A/D converter 9c is input to the microcomputer 10, and temperature data of the pot 11 and the base 1 are input.

The operation of the above configuration will be explained according to the flowchart of FIG.

In step 100, a heat retention process begins. In step 101, the microcomputer 10 determines whether the temperature θ of the pot 1 is higher or lower than 01, for example, 71.6° C. by inputting the output of the A/D converter 9C. If the temperature θ of pot 1 is higher than θ1, the process proceeds to step 102. In step 102, the output connected to the base of the microcomputer 10ij: I-transistor c, 7a is set to low level,
Transistor 6c.

7C is turned off, relay contact 6a and thyristor 7a are turned off, and power supply to bottom heater 2 and body heater 3 is stopped.

Next, the process proceeds to step 103, where the microcomputer 1
0 is the output connected to the base of transistor 8C, 1
Set the level to zero for 3 seconds out of 6 seconds, and set transistor 8C to 16
Turn on the thyristor 8a for 3 seconds, turn on the thyristor 8a, and energize the lid heater 5 at an energization rate of 3/16 to raise the temperature of the lid 4 to prevent dew from forming on the lid 4. It can also evaporate dew. Next, the process proceeds to step 101. Conversely, in step 101, the temperature θ of the pot 1 is θ
1 If it is also low, proceed to step 104. In step 104, the output of the microcomputer 1o connected to the transistor 6C is set to high level for 1 second out of 16 seconds, the transistor 6C is turned on for 1 second out of 16 seconds, the relay coil 6b is energized, and the relay contact 6a is turned on at 1 out of 16 seconds. It is turned on for a second, and the bottom heater 2 is energized at a 1/16 energization rate. In addition, the output of the microcomputer 10 connected to the transistor 7C is set to high level for 15 seconds out of 16 seconds, the transistor 7C is turned on for 16 seconds out of 16 seconds, and the thyristor 7
Turn on a for 16 seconds out of 16 seconds, and apply 15/1 to body heater 3.
Electrification is applied at an energization rate of 6. Furthermore, microcomputer 1
(J is the output connected to the pace of transistor 8C for 8 seconds out of 16 seconds) - Set the output level to 8 out of 16 seconds, turn on transistor 8C for 8 out of 16 seconds, and turn on thyristor 8a for 8 out of 16 seconds.
It is turned on for seconds to energize the lid heater 5 at an energization rate of 8/16. The timing at which the bottom heater 2, body heater 3, and lid heater 6 are energized in the top 104 will now be explained with reference to FIG. As shown in FIG. 4(a), Φ)t(a), the microcomputer 10 regards 16 seconds as one period, energizes the bottom heater 2 for the first second, and energizes the body heater 3 for the next 16 seconds. energize. Furthermore, the lid heater 6 is controlled to be energized for 8 seconds in the latter half of the 16 seconds. Next step 1
Proceed to 05. In step 105, the temperature θ of pot 1 is 01
For example, the microcomputer 1o determines whether the temperature is higher or lower than 71.6° C. by inputting the output of the A/D converter 9C. If the temperature θ of pot 1 is higher than θ1, the process proceeds to step 106. In step 106, the microcomputer 1o connects the transistors 6c and 7c.

The output connected to the base of 8c is set to low level, transistors 6c, 7c, and 8a are turned off, relay contact 6a and thyristor 7a, and 8a are turned off, and the bottom heater 2, body heater 3, and lid heater 5 are energized. and step 105
Return to Conversely, in step 105, the temperature θ of pot 1 is 0.
1 If the value is lower than 14, proceed to step 104 and repeat the above operation.

As described above, according to the electric rice cooker of the first embodiment of the invention, the lid heater 5 is not energized during the period from immediately after the rice cooking process enters the warming process until the temperature of the pot 1 falls below the warming temperature. It is possible to prevent dew from forming on the inside of the lid 4 by heating the lid 4 and raising the temperature of the lid 4. Also, when the temperature of the pot 1 falls below the heat retention temperature, the power supply to the bottom heater 2, body heater 3, and lid heater 6 is controlled to keep the temperature of the lid 4 at a temperature that does not allow dew to form, and to keep the temperature of the pot 1 warm. Since the temperature can be maintained, dew is prevented from forming on the inside of the lid 4 during heat retention, and the rice can be kept warm without deteriorating the taste, shape, etc. of the cooked rice due to the dew falling onto the rice.

Next, a second embodiment of the invention will be described based on FIG. 6. Components having the same configuration as the embodiment of the first invention are given the same reference numerals, and the explanation thereof will be omitted.

In FIG. 5, a lid temperature detection means 13 detects the temperature of the lid 4. As shown in FIG. In addition, the control means 1416 base 7 inputs signals from the lid temperature detection means 13 and the pot temperature detection means 9, and controls the period from immediately after entering the heat retention step from the rice cooking process until the temperature of the pot 1 falls below the heat retention temperature. , controls the lid heater drive means 8, energizes the lid heater 6 at a constant energization rate or stops energizing the lid heater 6 so that the temperature of the lid 4 becomes a constant temperature;
When the temperature of the pan 1 becomes lower than the heat retention temperature, the bottom heater drive means 6, the body heater drive means 7, and the lid heater drive means 8 are controlled, and the pot 1 is heated.
Bottom heater 2 and body heater 3 so that the temperature of
and lid heater 5 are controlled to be energized at a constant energization rate or to stop energization.

FIG. 6 is a specific circuit diagram, in which the lid temperature detection means 13 includes a thermistor 13a, a resistor 1sb, an A/D converter 13C2 and a resistor 13.
d and 13e. A voltage corresponding to the lid temperature is input to the A/D converter 13c by the thermistor 13a and the resistor 13b. pA/D by resistors 13d and 13e
A reference voltage for A/D conversion is input to the converter 13c. Further, the output of the A/D converter 130 is inputted to a control means (hereinafter referred to as a microcomputer) 14, and temperature data of the lid 4 is inputted thereto.

Next, the operation of the above configuration will be explained according to the flowchart of FIG. In step 200, a heat retention process begins. In step 201, the temperature θ of pot 1 is 01, for example 7
The microcomputer 14 inputs the output of the A/D converter 9C and determines whether it is higher or lower than 1.5°C. pot 1
If the temperature θ is higher than 01, the process proceeds to step 202. In step 202, the microcomputer 1
4 sets the outputs connected to the bases of transistors 6C and 7 (+) to a low level, turns off transistors 6c and 7c, turns off relay contact 6a and thyristor 7a, and stops energizing the bottom heater 2 and body heater 3. do.

Next, the process proceeds to step 203. In step 203, the lid 4
The microcomputer 14 inputs the output of the A/D converter 13c and determines whether the temperature φ is higher or lower than φ1, for example, 112° C. If the temperature φ of the lid 4 is higher than φ1, the process proceeds to step 204. In step 204, the 17 base of the microcomputer 14 is connected to the base of the transistor 8C.

The output flow level is set, the transistor 8C is turned off, the thyristor 8a is turned off, and the power supply to the lid heater 5 is stopped. Conversely, if the temperature φ of the lid 4 is lower than φ1 in step 203, the process proceeds to step 205. Step 205
Then, the output of the microcomputer 14 connected to the base of the transistor 8C is set to high level for 3 seconds out of 16 seconds.
By turning on the transistor 8C for 3 seconds out of 16 seconds, the thyristor 8a is turned on for 3 seconds out of 16 seconds, and the lid heater 5 is energized at a 3/16 energization rate to raise the temperature of the lid 4 and cause dew to form on the lid 4. Even if dew does form, it can be evaporated. Step 204 and Step 20
Step 5 returns to step 201. In step 201, if the temperature θ of pot 1 is lower than 01, step 206
Proceed to. The operations from step 206 to step 208 are the same as those from step 104 to step 106 in the flowchart of the first invention (FIG. 3).

As described above, according to the electric rice cooker of the second embodiment of the invention, the lid 4 is heated immediately after the rice cooking process starts the heat retention process or until the temperature of the 18-pot pot 1 falls below the heat retention temperature. A constant current is supplied to the lid heater 5 so that the temperature is such that no dew forms, a temperature that allows dew to evaporate even if dew forms, and a constant temperature that does not affect the durability of the lid heater 6. It can be energized or de-energized at certain rates. Furthermore, when the temperature of the pot 1 falls below the heat retention temperature, the power supply to the bottom heater 2, body heater 3, and lid heater 5 is controlled to keep the temperature of the lid 4 at a temperature that does not allow dew to form, and to keep the temperature of the pot 1 warm. Since the temperature can be maintained at the same temperature, it is possible to prevent dew from forming on the inside of the lid 4 while keeping it warm, and the dew can fall onto the cooked rice, keeping the rice warm without degrading the taste or shape of the cooked rice. It is possible to prevent abnormal heating of the lid heater 5 and increase the durability of the lid heater 5.

Next, an embodiment of the third invention will be described.

The control means 14 in FIG. 5 inputs signals from the lid temperature detection means 13 and the pot temperature detection means 9, and controls the period from immediately after the rice cooking process to the heat retention process until the temperature of the pot 1 falls below the heat retention temperature. , a barrel heater drive means 7 and a lid heater drive means 8
The body heater 3 and the lid heater 5 are energized at a constant energization rate or stopped so that the temperature of the lid 4 becomes a constant temperature of 19 degrees Celsius, and when the temperature of the pot 1 falls below the keeping temperature. , controls the bottom heater drive means 6, the body heater drive means 7, and the lid heater drive means 8, and controls the pot 1.
Bottom heater 2 and body heater 3 so that the temperature of
and lid heater 6 are controlled to be energized at a constant energization rate or to stop energization.

Next, the operation will be explained according to the flowchart shown in FIG. At step 300, a heat retention process begins.

In step 301, the temperature θ of pot 1 is θ1, for example, 71.6.
The microcomputer 14 inputs the output of the A/D converter 9C and determines whether the temperature is high or low.

If the temperature θ of pot 1 is higher than θ1, step 302
Proceed to. In step 302, the microcomputer 14 sets the output connected to the base of the transistor 6C to a low level, turns off the transistor 6C, turns off the relay contact 6a, and stops energizing the bottom heater 2. Next, the process advances to step 303. In step 303, the lid 4
The microcomputer 14 inputs the output of the A/D converter 13c and determines whether the temperature φ is higher or lower than φ1, for example, 112°C. If the temperature φ of the lid 4 is higher than φ1, the process proceeds to step 304. In step 304, the output of the microcomputer 14 connected to the bases of the transistors 7c, 8c is set to low level, and the transistors 7c, 8c are turned off.
8a is turned off, and the trunk heater 3. The electricity supply to the lid heater 5 is stopped. Conversely, in step 303, the temperature φ of the lid 4 becomes φ1.
If it is very low, proceed to step 305. Step 30
5, as shown in Figure 9(a), the first half of 16 seconds is 3.
For the second period, the output of the microcomputer 14 connected to the base of the transistor 8C is set to high level, the transistor 8C is turned on for 3 seconds in the first half of 16 seconds, the thyristor 8a is turned on for 3 seconds in the first half of 16 seconds, and the lid heater 5 is turned on.
The energization rate is set to 3/16 to raise the temperature of the lid 4 to prevent dew from forming on the lid 4, and even if dew forms, the dew can be evaporated. Furthermore, as shown in Figure 9 0)), 21
Be-7 During the last 3 seconds of 16 seconds, the output of the microcomputer 14 connected to the base of transistor 7C is set to high level, transistor 7C is turned on for 3 seconds during the latter half of 16 seconds, and thyristor 7a is turned on during the latter half of 16 seconds. Turn it on for 3 seconds, energize the body heater 3 at an energization rate of 3/16,
The temperature of the side part of the pot 1 is raised to prevent dew from forming on the inside of the side part of the pot 1, and even if dew forms, the dew can be evaporated. Step 304 and step 305 return to step 301. In step 301, if the temperature θ of the pot 1 is lower than θ1, the process proceeds to step 306. The operations from step 306 to step 308 are the same as steps 104 to 106 in the flowchart of the first invention (FIG. 3).

As described above, according to the electric rice cooker of the third embodiment of the invention, the temperature of the lid 4 is kept low during the period from immediately after the rice cooking process to the heat retention process until the temperature of the pot 1 falls below the heat retention temperature. At the same time, the temperature is set at a temperature that does not allow dew to form, a temperature that allows dew to evaporate even if it does form, and a constant temperature that does not affect the durability of the 22-baer lid heater 6. The body heater 3 and the lid heater 6 are set at a temperature that prevents dew from forming on the inside of the side surfaces of the body, and at a temperature that allows the dew to evaporate even if it does form.
It is possible to energize or stop energizing each at a fixed energization rate. Also, when the temperature of pot 1 falls below the keep-warm temperature, the bottom heater 2
By controlling the power supply to the body heater 3 and lid heater 5, the temperature of the lid 4 and the temperature inside the side portion of the pot 1 can be maintained at a temperature that does not allow dew to form, and the temperature of the pot 1 can be maintained at a heat retention temperature. This prevents dew from forming on the inside of the lid 4 and the pot 1 while keeping the rice warm, and allows the rice to be kept warm without deteriorating the taste or shape of the cooked rice. It is also possible to prevent abnormal heating and increase the durability of the lid heater 5.

In addition, in the above embodiment, the temperature φ at which the lid 4 is kept constant is
1 is the temperature at which dew does not form, and even if it does form, it is the temperature at which it can evaporate.

The temperature is set so as not to affect the durability of the lid heater 5. Further, in this embodiment, the bottom heater 2 is a normal sheath 23,-.

Although a heater is used, any heater may be used as long as it heats the bottom portion of the pot 1, for example, an induction heating type heater may be used without any problem.

Effects of the Invention As is clear from the above embodiments, according to the first invention,
The lid heater is energized for the period from immediately after entering the warming process from the rice cooking process until the temperature of the pot falls below the warming temperature.
When the temperature of the pot falls below the keep-warm temperature, the power supply to the bottom heater, body heater, and lid heater can be controlled to keep the pot at the keep-warm temperature, which prevents dew from forming on the inside of the lid while keeping it warm. This prevents dew from falling onto cooked rice and keeps it warm without degrading the taste or shape of the cooked rice. Further, according to the second invention, the lid heater is energized at a constant rate so that the temperature of the lid remains constant for a period from immediately after entering the warming process from the rice cooking process until the temperature of the pot falls below the warming temperature. The power can be turned on or off, and when the temperature of the pot falls below the keep-warm temperature, the power supply to the bottom heater, body heater, and lid heater can be controlled to keep the pot's temperature at the keep-warm temperature. Prevents dew from forming on the inside of the lid, allowing the dew to fall onto the cooked rice and improve the taste of the cooked rice.

In addition to being able to maintain heat without deteriorating its shape, it also prevents the lid heater from overheating and increases the durability of the lid heater.

Furthermore, according to the third invention, the body heater and the lid heater are each set so that the temperature of the lid is kept at a constant temperature during the period from immediately after entering the warming process from the rice cooking process until the temperature of the pot becomes below the warming temperature. It is possible to turn on electricity at a certain energization rate or stop the electricity supply, and when the temperature of the pot falls below the keep-warm temperature, the power supply to the bottom heater, body heater, and lid heater can be controlled to keep the pot temperature at the keep-warm temperature. , prevents dew from forming on the lid and the inner part of the pot while keeping the food warm, allowing the rice to be kept warm without degrading the taste or shape of the food due to dew falling onto the food, and preventing abnormal heating of the lid heater. However, it is also possible to increase the durability of the lid heater.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an electric rice cooker according to an embodiment of the present invention.
FIG. 2 is a specific circuit diagram of the electric rice cooker, and FIG. 3 is a flowchart showing the operation of the electric rice cooker. 25,,-. Fig. 4-P□F→ is a energization timing diagram of each heater in step 104 of Fig. 3 in this case, Fig. 5 is a block diagram of an electric rice cooker according to another embodiment of the present invention, and Fig. 6 is the same. A specific circuit diagram of the electric rice cooker, FIG. 7 is a flow chart showing the operation of the electric rice cooker, FIG. 8 is a flow chart showing the operation of the electric rice cooker according to another embodiment of the present invention, and FIG. Figure 10 is a block diagram of a conventional electric rice cooker, and Figure 11 is a flowchart showing the operation of the conventional electric rice cooker. 1...Pot, 2...Bottom heater, 3...
...Body heater, 4...Lid, 6...Lid heater, 6...Bottom heater driving means, 7...
...Body heater drive means, 8...Lid heater drive means, 9...Pot temperature detection means, 1o...
control means.

Claims (3)

[Claims] (1) A pot for storing rice, a bottom heater drive means for energizing a bottom heater that heats the bottom of the pot, and a body heater drive means for energizing a body heater that heats a side surface of the pot. a lid heater drive means for energizing a lid heater that heats a lid for closing the pot; a pot temperature detection section for detecting the temperature of the pot; and a control section for inputting a signal from the pot temperature detection section. The control means controls the lid heater driving means to energize the lid heater at a constant energization rate during a period from immediately after entering the warming step from the rice cooking process until the temperature of the pot falls below the warming temperature. When the temperature of the pot falls below the heat retention temperature, the bottom heater drive means, the body heater drive means, and the lid heater drive means are controlled so that the bottom heater and the body heater are controlled so that the temperature of the pot becomes the heat retention temperature. and the lid heater, each of which is controlled to be energized at a constant energization rate or to be de-energized. (2) comprising a pot temperature detection means for detecting the temperature of the pot, a lid temperature detection means for detecting the temperature of the lid, and a control means for inputting signals from the lid temperature detection means and the pot temperature detection means; The control means controls the lid heater drive means for a period from immediately after entering the warming step from the rice cooking process until the temperature of the pot becomes below the warming temperature, and controls the lid heater to maintain the temperature of the lid at a constant temperature. The current is applied at a constant energization rate or the current is stopped, and when the temperature of the pot falls below the heat retention temperature, the bottom heater drive means, the body heater drive means, and the lid heater drive means are controlled to bring the temperature of the pot to the heat retention temperature. 2. The electric rice cooker according to claim 1, wherein the bottom heater, the body heater, and the lid heater are controlled to be energized at a constant energization rate or to stop energization, respectively. (3) During the period from immediately after entering the warming process from the rice cooking process until the temperature of the pot falls below the warming temperature, the body heater drive means and the lid heater drive means are controlled so that the temperature of the lid remains at a constant temperature. 3. The electric rice cooker according to claim 2, wherein the heater and the lid heater are controlled to be energized at a constant energization rate or to be de-energized.