JP2003135274A - an electronic pot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability of a relay contact for ON / OFF of a water heater in detecting empty cooking of an electric pot. SOLUTION: An inner vessel capable of boiling water and keeping heat, a first heating means of high power for heating the inner vessel, a second heating means of low power for heating the inner vessel, and the first Heating control means for performing each heating control of the heating means and the second heating means, temperature detection means for detecting the temperature of water in the inner vessel through the bottom of the inner vessel, and detection by the temperature detection means. Temperature rising rate calculating means for calculating the rising rate of the temperature of the water, time measuring means for measuring the time elapsed since the start of boiling water, and empty cooking determining means for determining whether the inner container is empty. In the electric pot, the empty cooking judging means energizes the first heating means for a predetermined time immediately after the start of boiling water, and then turns off the first heating means to energize only the second heating means for a predetermined time. The temperature rise rate after At this time, it is configured to judge that it is empty cooking, so that the number of times of ON of the first heating means at the time of boiling water is sufficient.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric pot having a function of detecting empty cooking.

[0002]

2. Description of the Related Art In a conventional electric pot disclosed in, for example, Japanese Patent No. 3012953, the first electric power for boiling water is first.
The heating means and the second heating means of low electric power for heat retention are provided, and after boiling water is started, both the first and second heating means are operated to heat and boil the water in the inner container, Only the second heating means keeps the temperature at a predetermined temperature.

On the other hand, a temperature sensor (bottom sensor) such as a thermistor is provided on the bottom surface side of the inner container, and the control unit measures a predetermined elapsed time from the start of the boiling. Is provided.

Then, the temperature sensor detects an increase in the water temperature in the inner container, and the time measuring means measures the elapsed time from the start of the boiling.

At this time, from the start of boiling water until a predetermined time elapses, the first heating means is controlled to be turned on and off at a predetermined duty ratio, while the temperature sensor controls the temperature inside the inner container. The temperature of water is detected, and when the detected temperature rise rate of the water in the inner container is equal to or higher than a predetermined rise rate, it is determined that there is no water in the inner container, and the first cooking stove is used. , Turn off the second heating means.

On the other hand, in the opposite case, it is assumed that there is water in the inner container, and after the lapse of the predetermined time, the first, second
The heating means is continuously energized to continue boiling water.

According to such a construction, from the start of boiling water to the inner container with electric power smaller than the maximum electric power due to continuous energization by the duty control of the first heating means within a predetermined time required for detecting empty cooking. Even if the inner container is heated while it is empty, even if the temperature rise rate of water is detected and the energization is stopped after the temperature detected by the temperature sensor begins to rise, it is possible. Since the degree of temperature rise of the inner container can be suppressed as low as possible, damage (overheating damage) to the inner container, the temperature sensor and other parts is reduced.

[0008]

However, in the case of the configuration in which the duty control is performed by turning on and off the first heating means for boiling water as described above, on the other hand, by increasing the number of times the relay contact is opened and closed, Prone to damage,
Its durability and reliability are problems.

Further, there is a problem in that the durability of the first heating means (boiling heater) itself becomes a problem due to the turning on / off of the power source, and at the same time, a lot of open / close noise (ON / OFF noise) of the relay contact occurs.

The present invention has been made in order to solve such a problem, and when detecting the boiling of water at the start of boiling, the first heating means for boiling water need only be turned on once. In order to improve the durability and reliability of the relay contact and the water heater, and to provide an electric pot with an empty cooking detection function that does not cause the generation of relay contact opening and closing noise. Is.

[0011]

In order to achieve the above object, the present invention is provided with the following means for solving the problems.

(1) Invention of Claim 1 An electric pot according to the present invention heats an inner container capable of boiling water and retaining heat, a first heating means of high power for heating the inner container, and the inner container. A second heating means of low power;
Heating control means for controlling each heating of the first heating means and the second heating means, temperature detecting means for detecting the temperature of water in the inner container via the bottom of the inner container, and the temperature detection Temperature rise rate calculating means for calculating the temperature rise rate of the water detected by the means, time measuring means for measuring the elapsed time from the start of boiling water, and an empty cooking determination means for determining idle cooking of the inner container In the electric pot provided with, the empty cooking determination means energizes the first heating means for a predetermined time immediately after the start of boiling, and then turns off the first heating means.
Then, when the temperature increase rate after energizing only the second heating means for a predetermined time is equal to or higher than the predetermined temperature increase rate, it is configured to determine that the rice is cooked.

Therefore, in the above construction, the first heating means is turned on only once immediately after starting boiling water.
Compared with the conventional configuration, the number of times the relay contact is turned on and off is much reduced, and the durability and reliability of the relay contact and the first heating means are greatly improved. Also, the amount of relay contact opening / closing noise (ON / OFF noise) generated is reduced.

Further, since the energizing time of the first heating means itself can be shortened in relation to the energizing time of the second heating means, it is possible to reduce the power consumption amount during the idle cooking determination time. As a result, the damage to the inner container and the temperature detecting means during the empty cooking is reduced.

(2) Invention of Claim 2 In the electric pot of this invention, in the invention of Claim 1, the energization time to the first heating means is longer than the energization time to the second heating means. It is characterized by being short.

Therefore, in the above construction, the heating time of the first heating means can be shortened, so that the damage to the inner container, the temperature detecting means and the like becomes smaller.

(3) Invention of Claim 3 The electric pot of the present invention is an inner container capable of boiling water and retaining heat, a first heating means of high power for heating the inner container, and the inner container. A second heating means of low power;
Heating control means for controlling each heating of the first heating means and the second heating means, temperature detecting means for detecting the temperature of water in the inner container via the bottom of the inner container, and the temperature detection Temperature rise rate calculating means for calculating the temperature rise rate of the water detected by the means, time measuring means for measuring the elapsed time from the start of boiling water, and an empty cooking determination means for determining idle cooking of the inner container In the electric pot provided with, the empty cooking determination means energizes the first heating means for a predetermined time immediately after the start of boiling, and then turns off the first heating means.
When the temperature rise rate after a predetermined time has elapsed is equal to or higher than the predetermined temperature rise rate, it is configured to determine that the rice is cooked.

Therefore, in this structure, the first heating means first turns on the water only once immediately after boiling,
Compared with the conventional configuration, the number of times the relay contact is turned on and off is much reduced, and the durability and reliability of the relay contact and the first heating means are greatly improved. Also, the amount of relay contact opening / closing noise (ON / OFF noise) generated is reduced.

Further, since the second heating means is not turned on after the first heating means is turned off, it is possible to further reduce the power consumption within the idle cooking determination time. Further, damage to the inner container and the temperature detecting means during cooking in the air is reduced.

(4) Invention of Claim 4 The electric pot of the present invention comprises an inner container capable of boiling water and keeping warm, a first heating means of high power for heating the inner container, and the inner container. A second heating means of low power;
Heating control means for controlling each heating of the first heating means and the second heating means, temperature detecting means for detecting the temperature of water in the inner container via the bottom of the inner container, and the temperature detection Temperature rise rate calculating means for calculating the temperature rise rate of the water detected by the means, time measuring means for measuring the elapsed time from the start of boiling water, and an empty cooking determination means for determining idle cooking of the inner container In the electric pot provided with, the empty cooking determination means energizes only the second heating means for a predetermined time immediately after the boiling is started, and then the second heating means is turned on.
The temperature increase rate after the first heating means is energized for a predetermined time without being set to FF, and then the first heating means is turned off and a predetermined time has elapsed, is equal to or higher than the predetermined temperature increase rate. It is configured to sometimes determine that the rice is cooked in the air.

Therefore, in this configuration, at least the first heating means is turned on only once after the start of boiling, so that the relay contact is turned on and off as compared with the conventional configuration.
The number of times is much smaller, and the durability and reliability of the relay contact and the first heating means are greatly improved. Also, the amount of relay contact opening / closing noise (ON / OFF noise) generated is reduced.

Also, since the energization time of the first heating means itself can be shortened in relation to the energization time of the second heating means, it is possible to reduce the amount of power consumption during the idle cooking determination time. As a result, the damage to the inner container and the temperature detecting means during the empty cooking is reduced.

(5) Invention of Claim 5 An electric pot according to the present invention heats an inner container capable of boiling water and retaining heat, a first heating means of high power for heating the inner container, and the inner container. A second heating means of low power;
Heating control means for controlling each heating of the first heating means and the second heating means, temperature detecting means for detecting the temperature of water in the inner container via the bottom of the inner container, and the temperature detection Temperature rise rate calculating means for calculating the temperature rise rate of the water detected by the means, time measuring means for measuring the elapsed time from the start of boiling water, and an empty cooking determination means for determining idle cooking of the inner container In the electric pot provided with, the empty cooking determination means energizes only the second heating means for a predetermined time immediately after the boiling is started, and then the second heating means is turned on.
If the temperature rise rate when the first heating means is energized for a predetermined time without turning to FF and then the first and second heating means is turned off is equal to or higher than the predetermined temperature rise rate Is made.

Therefore, in this configuration, at least the first
Since the heating means of No. 1 turns on only once after starting boiling water, the number of times the relay contact is turned on and off is much smaller than that of the conventional configuration, and the durability and reliability of the relay contact and the first heating means are improved. Greatly improved. Also, the amount of relay contact opening / closing noise (ON / OFF noise) generated is reduced.

Further, since the energizing time of the first heating means itself can be shortened in relation to the energizing time of the second heating means, it is possible to reduce the power consumption amount during the idle cooking determination time. As a result, the damage to the inner container and the temperature detecting means during the empty cooking is reduced.

[0026]

As a result of the above, according to the present invention, it is possible to provide a durable and reliable electric pot which solves the above-mentioned problems of the conventional electric pot.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION The structure and operation of an electric pot main body and a control device common to each of the embodiments described later of the electric pot of the present invention will be described below with reference to the accompanying drawings.

(Structure of Electric Pot Main Body) First, FIGS. 1 to 3 show the structures of the main body and main parts of an electric pot common to each embodiment of the present invention described later.

First, as shown in FIGS. 1 and 2, this electric pot comprises a container body 1 having an inner container 3 for storing hot water,
A lid 2 that opens and closes the upper opening of the container body 1, a boiling water heater 4A that is a heating unit that heats the inner container 3 when boiling the water, and a heating unit that heats the inner container 3 when the temperature is kept warm. Insulating heater 4B, hot water supply passage 5 for supplying hot water in the inner container 3 to the outside, and a flow rate sensor 80 provided in the middle of the hot water supply passage 5 for actual flow rate measurement
An electric hot water supply pump 6 that sends hot water in the inner container 3 to the outside through the hot water supply passage 5 when the AC power supply is connected, and the hot water supply passage 5 when the AC power supply is not connected. And an air type manual hot water supply pump 18 for sending hot water in the inner container 3 to the outside.

The container body 1 has a cylindrical outer case 7 made of synthetic resin that constitutes an outer side surface thereof, the inner container 3 that constitutes an inner side surface part, and the outer case 7 and the inner container 3 on the upper side. It is composed of an annular shoulder member 8 made of synthetic resin, which is integrally connected and fixed, and a dish-shaped bottom member 9 made of synthetic resin, which constitutes the bottom portion.

The inner container 3 is a vacuum double structure having a high heat retention performance in which a vacuum heat insulating space is provided between an inner cylinder 10 made of stainless steel having a bottomed cylindrical shape and an outer cylinder 11 made of stainless steel having a cylindrical shape. The bottom portion of the inner cylinder 10 is formed with only the bottom surface portion of the inner cylinder 10 excluding the outer peripheral portion. The single plate portion 3a is formed so as to project slightly upward, and on the lower surface side thereof, the boiling water heater 4A and the heat retaining heater 4B (for example, two sets of heating elements having different wattages are held on a mica plate). It consists of a mica heater).

At the upper end of the inner container 3, the inner cylinder 10
A small-diameter water supply port 3b having a heat-keeping structure is formed by drawing the upper end portion of the side toward the central axis direction. Reference numeral 12 indicates the temperature of the inner container 3 (in other words, the inner container 3
It is a bottom sensor (hot water temperature sensor) that acts as hot water temperature detecting means for detecting the temperature of the hot water inside, and is composed of a thermistor. Further, reference numeral 13 is the full water level WL _{2 of the} inner container 3
Is a convex full-water level display unit for displaying. Further, WL ₁ indicates a low water level (1/2 water level).

The lid 2 is composed of an upper plate 14 made of synthetic resin and a lower plate 15 made of synthetic resin whose outer peripheral edge is connected to the upper plate 14, and is provided at the rear portion of the shoulder member 8. The hinge receiver 16 is supported by a hinge pin 17 so as to be openable and closable in the vertical direction and detachable.

The lid 2 is an air-operated manual hot water pump which is compressed by a manual pressing operation so that hot water can be supplied to the outside through the hot water supply passage 5 even when an AC power source is not connected. 18 are provided. The manual hot water supply pump 18 is of a bellows type disposed in a cylindrical portion 19 formed in the substantially central portion of the lid body 2 and has a bellows structure via a pressing cover 20A and a pressing plate 20B. By pressing the bellows 20C downward, the pressurized air 20D in the bellows 20C is blown into the inner container 3 through the air blowing port, and the hot water in the inner container 3 is supplied by the blowing pressure of the pressurized air. It is adapted to be pushed out through the passage 5. Further, 20E is a restoring spring of the bellows 20C upward, and 15A is a bellows supporting plate on the lower plate 15 side. In addition, reference numerals 21a to 21d are vapor discharge passages of the lid body 2 which are communicated with each other from the lower side to the upper side, and 22 is a fall-stop water disposed midway on the vapor discharge portion 21a side of the vapor discharge passages 21a to 21d. It is a valve.

On the lower surface of the lower plate 15 of the lid body 2,
An inner cover member 23 made of metal is fixed, and an outer peripheral edge of the inner cover member 23 is made of a heat-resistant rubber that is pressed against the upper surface of the water supply port 3b of the inner container 3 when the lid 2 is closed. The seal packing 24 is provided.

At a lower position of the inner container 3 on the upstream end side of the hot water supply passage 5, a DC type electric hot water supply pump 6 is provided through a hot water introducing cylinder 6a on the inner container 3 side and a hot water suction port 6b on the hot water supply pump side.
In the hot water supply passage 5, the hot water sucked from the hot water inlet 6b through the hot water introduction tube 6a is discharged from the discharge port 6c by the pumping action of the electric hot water supply pump 6. After passing through the straight pipe part 5b of the hot water supply passage 5,
It passes through the flow rate detection passage in the flow rate sensor 80 and is guided from the fall stop water valve side connecting pipe 5c to the hot water pouring outlet 5d to the outside.

Further, reference numeral 35 is an operation panel section having operation surfaces of various switches described later and a display surface of a liquid crystal display section, and 51a is a microcomputer control section 60 and various switches 38 to 41, 42 described below. , 43, a microcomputer board including a liquid crystal display device (driving unit), and the like, 51 denotes a liquid crystal display unit 4
7, a support member 50, a drive circuit for the electric hot water supply pump 6, a heating control circuit for the hot water heater 4A, the warming heater 4B, a buzzer 56 for informing of boiling and informing of boiling, a drive circuit for the buzzer 56, stabilization A power supply board including a DC power supply circuit and the like.

On the operation panel section 35, there is a hot water supply switch 38, a hot water supply lock release switch 39, a reboil / heat retention selection switch 40, a good night timer switch 41, and hot water supply amount setting up / down switches 42 and 43 when the fixed hot water supply mode is selected. A reboiling display LED 44, a heat retention operation display LED 45, a hot water supply lock release display LED 46, a liquid crystal display unit 47, and the like are provided.

The liquid crystal display section 47 is provided with, for example, a time / time / hot water temperature / operating state and other display section 47a, a heat retention set temperature display section 47b, and a mahobin heat retention display section 47c. Various information is displayed.

This electric hot water supply type electric pot has a continuous hot water supply mode in which the electric hot water supply pump 6 can be continuously driven to discharge hot water as long as the hot water supply switch 38 is pressed.
Even if the hot water supply switch 38 is continuously pressed, the electric hot water supply pump 6 stops when the predetermined amount of hot water preset by the up / down switches 42 and 43 is poured out, and there are two kinds of hot water supply modes. ing.

The flow rate sensor 80 used therefor
For example, the spiral rotary screw blades 82 are loosely fitted to the outer periphery of the rotary support shaft 81 via a cylindrical hub, and they are fitted to the upper end of the straight pipe portion 5b of the hot water supply passage 5 via a fitting cylinder 83. It is configured to be fixed.

(Structure of Control Circuit Section) FIG. 3 is a block diagram showing the structure of the control circuit section in the electric pot body having the above structure.

In FIG. 3, reference numeral 57 is, for example, a smoothing capacitor and a power supply IC, and a DC stabilizing power supply unit for supplying a DC power supply to the microcomputer control unit 60, the heating control unit 54, the pump power supply unit 55, and the like, and 54 is a kettle. A heating control unit for ON / OFF control of the heater 4A and the heat retention heater 4B,
Reference numerals 4A and 4B are heating means composed of the above-described hot water heater 4A and warming heater 4B, 38 to 43 are the above-mentioned hot water supply switch and other switches, and 6 is the above-mentioned DC type electric hot water supply pump.

When the water heater heater 4A outputs a heater ON signal from the microcomputer controller 60 to the heating controller 54, for example, it drives a power relay via a transistor (not shown), and in response thereto. It is activated by turning on the relay contact (power switch).

In addition, the heat retaining heater 4B causes the microcomputer controller 60 to apply the heat retaining heater O to the heating controller 54.
When the N signal is output, for example, a transistor (not shown) is turned on to drive the triac to operate.

Further, the microcomputer control section 60 further includes various LED display sections such as the liquid crystal display section 47, the reboiling display LED 44, the heat retention operation display LED 45, the hot water supply lock release display LED 46, the hot water supply switch 38, and the reboiler. / Various operation units such as the heat retention selection switch 40, the hot water supply lock release switch 39, and the night timer switch 41, the bottom sensor (thermistor) 12, various sensor units such as the flow rate sensor 80, the buzzer 56, etc. respectively have input / output ports (not shown). Connected through.

In the above electric pot, when boiling water is detected, for example, as will be described later, the boiling water heater 4A or the warming heater 4B is used to detect empty cooking, and as a result, it is determined that it is not empty cooking. After that, after heating to a boiling state quickly with high heating output of both the heater 4A and the heat-retaining heater 4B, a boiling notification (boiling completion notification) is given by the buzzer sound of the buzzer 56 to turn off the heating heater 4A. After that, the process proceeds to the heat retention step.

In the heat retention step, the hot water temperature T detected by the bottom sensor (hot water temperature sensor) 12 is displayed for each predetermined temperature level between 98 ° C and 10 ° C, for example.

(Dry Cooking Detection Control According to First Embodiment) Next, the flow charts of FIGS. 4 and 5 and the time chart of FIG. 6 show the contents of the empty cooking detection control of the electric pot according to the first embodiment of the present invention. Is shown.

That is, in the control, when the power plug is first connected to the power circuit of the electric pot, the control is started by detecting the power plug.

Therefore, first, the microcomputer of the microcomputer control section determines whether or not the boiling control is started and the boiling is being performed (step S ₁ ). As a result, when NO,
Control ends as it is. On the other hand, when it is determined to be in the boiling water state of YES, it is subsequently determined whether or not the determination of empty cooking (executed only once in this system) has been completed (step S ₂ ). Even if the result of the determination is YES, since it is said that the one-time cooking control is sufficient for the system design as described above, the control is ended as it is. On the other hand, when the determination result is NO, that is, when the empty cooking determination is not completed yet (when it is not performed), the hot water heater 4A and the warming heater 4B are immediately turned on (as shown in the time chart of FIG. 6). in the energized state), starts the heating of the inner container 3 at high power (step S _3).

Then, subsequently, the counting operation of the timer for counting various set times such as a predetermined set time of 20 seconds sufficient to see the temperature rise of the inner container 3 is started (step S ₄ ). This timer is set after starting the water heating in the claims (the water heating heater 4A
Corresponds to a time measuring means for measuring the elapsed time (after turning ON).

After that, it is judged whether or not the set time of the timer is 20 seconds (count-up of 20 seconds) (step S ₅ ), and if NO, until the set time of 20 seconds elapses.
While connecting ON state of the boiler heater 4A and insulation heater 4B (Step S ₃₎ and timer count operation (step S _4), becomes a YES (20 seconds elapses), the elapsed time the 20 seconds, the time of FIG. 6 as shown in the chart, the process proceeds to the only kettle heater 4A of the large power to OFF (step S _6), air-cook determination control in a state in which only the to oN warmth heater 4B (step S _7).

This idle cooking determination control is performed as a subroutine, for example, as shown in the flowchart of FIG.

That is, first, based on the count value of the timer, a predetermined elapsed time of 40 seconds after the boiling water is started (the boiling water detection control is started) for detecting the hot water temperature required for the empty cooking determination. It is determined whether or not has passed (step S ₁ ). As a result, when the above-mentioned hot water temperature detection start time of 40 seconds has not elapsed for NO, once the control is finished,
Further, the elapse of 40 seconds is judged again.

On the other hand, when YES after the 40-second hot water temperature detection start time has elapsed, the basic data T ₁ of the hot water temperature detection value T (the first hot water temperature detection value for the first time) is used as the reference for determining the hot water temperature rise rate. ) Is stored in memory (step S ₂ ).
This hot water temperature detection control is based on the hot water temperature detection start time (40 seconds).
After the lapse of time, a 2-second cycle is performed.

As a result of the determination, at the first hot water temperature detection timing of NO when the basic data T ₁ is not yet stored in memory, the lowest hot water temperature which becomes the basic data T ₁ is next set. It is detected by the bottom sensor 12 and input (step S ₃ ). Then, after that, the elapse of the hot water temperature detection cycle of 2 seconds is determined. On the other hand, the same basic data T ₁ already exists YES
In the case of (the second and subsequent hot water temperature detections), the hot water temperature detection as the basic data T ₁ (step S ₃ ) is not performed, and it is subsequently determined whether or not the hot water temperature detection cycle of 2 seconds has elapsed. Yes (step S ₄ ).

Next, in either case of step S ₃ or step S ₂ , the hot water temperature detection cycle 2 is performed.
When seconds have elapsed (YES at Step S _4), and inputs the detected new hot water temperature data Tn to be compared (step S
₅ ).

Then, correspondingly, the number n of times of hot water temperature data detection every 2 seconds is counted (step S ₆ ).

Next, the newly detected hot water temperature data T
n is the previous data T_n-1Greater than or not, that is, hot water
Determine whether the temperature is changing in the rising direction (step
S ₇). As a result, if YES, the above step
S₆Set the hot water temperature detection count n every 2 seconds
It is determined whether or not the number of times is n times (n = 10 times).
Step S₈).

Then, as a result, if the hot water temperatures detected n times (10 times) every 2 seconds of YES are all changes in the rising direction, the final hot water temperature of the nth time (10th time) is finally obtained. It is determined whether or not the temperature difference ΔT = Tn−T ₁ between the data Tn (T ₁₀ ) and the first basic data T ₁ is equal to or larger than a predetermined set value ΔTs, and when YES, it is determined that the cooking is “blank”. (step S _10).

On the other hand, in contrast to this, when the current hot water temperature Tn is lower than the previous hot water temperature T _n-1 during the n hot water temperature detection periods, the water is determined to be NO in step S ₇ , or There is a sufficient amount of water in the inner container 3, the hot water if NO determination is such a small step S ₉ than when the increase rate ΔT of temperature is cooked empty, without performing air-cook determination, FIG 5
End the empty cooking control.

After the determination of the dry cooking is performed as described above, the process returns to step S _{7 and} thereafter in the flowchart of FIG.

Then, subsequently, as a system,
Confirm that the empty cooking determination process is complete (step S
₈ ) and then, based on the determination data, make a final decision on whether the rice is cooked empty or not (step S ₉ ).

As a result, in the case of NO non-dry cooking determination, in addition to the heat-retaining heater 4B, the above-mentioned boiling water heater 4A is turned on (energized state) again to start boiling water at a high output again (step S). ₁₀ ). On the other hand, if the determination is YES, the buzzer 56 notifies the user of the idle cooking (step S ₁₁ ), and further the above-mentioned boiling water heater 4
In addition to the OFF of A, in the OFF even warmth heater 4B, it ends the control (step S _12).

As described above, the electric pot according to the first embodiment of the present invention has the inner container 3 capable of boiling water and keeping warm.
A boiling water heater 4A as a high-power first heating means for heating the inner container 3, a low-power second heating means for heating the inner container 3, the first heating means and the second heating means. Insulating heater 4B as a heating control means for controlling each heating of the heating means, a bottom sensor 12 as a temperature detecting means for detecting the temperature of water in the inner container 3 through the bottom of the inner container 3, A temperature rise rate calculation means for calculating the rise rate of the temperature of the water detected by the bottom sensor 12 as the temperature detection means, a timer as a timekeeping means for measuring the elapsed time from the start of boiling water, and the above contents. In an electric pot provided with an empty cooking determination means for determining the empty cooking of the vessel 3, the empty cooking determination means first causes the boiling heater 4A as the first heating means to perform a predetermined time (20 seconds) immediately after the start of boiling. ) Turn on the power After the kettle heater 4A as the first heating means and to OFF, further, only a predetermined time insulation heater 4B as the second heating means (20
Second) When the temperature increase rate ΔT after energization is equal to or higher than a predetermined temperature increase rate ΔTs, it is configured to determine that the rice is cooked.

Therefore, in this configuration, first, the boiling water heater 4A as the first heating means is turned on only once immediately after starting the boiling, so that the boiling water heater is turned on as compared with the configuration of the conventional example (duty control) described above. The number of times the OFF relay contact is turned ON / OFF is significantly reduced, and the durability and reliability of the relay contact, the water heater 4A, etc. are greatly improved.

Further, the relay contact opening / closing noise (ON / OF
The amount of F noise) also decreases.

Further, in relation to the energization time of the heat retention heater 4B as the second heating means of 40 seconds, the energization time itself of the water heater 4A as the first heating means can be shortened to 20 seconds. Therefore, it is possible to reduce the amount of power consumption within the determination time for empty cooking.

As a result, the damage to the inner container 3 and the bottom sensor 12 as the temperature detecting means at the time of empty cooking is reduced.

(Dry Cooking Detection Control According to Second Embodiment) Next, the flowchart of FIG. 7 and the time chart of FIG. 8 show the contents of the empty cooking detection control of the electric pot according to the second embodiment of the present invention. There is.

That is, in the control, when the power plug is first connected to the power circuit of the electric pot, the control is started by detecting the power plug.

Therefore, first, the microcomputer of the microcomputer control unit determines whether or not the boiling control is started and the boiling is being performed (step S ₁ ). As a result, when NO,
Control ends as it is. On the other hand, when it is determined to be in the boiling water state of YES, it is subsequently determined whether or not the determination of empty cooking (executed only once in this system) has been completed (step S ₂ ). When the determination result is YES, it is determined that the actual dry cooking determination control needs to be performed only once in the system design as described above, and thus the present control is ended as it is. On the other hand, when the determination result is NO, that is, when the determination of empty cooking is not completed yet (when the determination is not performed once), the result of FIG.
As shown in the time chart of ( ₃ ), the boiling water heater 4A and the heat retention heater 4B are immediately turned on (energized state) to start heating the inner container 3 at high output (step S3).

Then, subsequently, a timer for counting various set times such as a predetermined set time of 20 seconds sufficient to see the temperature rise of the inner container 3 and a set time of 40 seconds for starting the hot water temperature detection control is counted. starting the operation (step S _4). This timer corresponds to the time measuring means for measuring the elapsed time from the start of boiling water (after boiling water and turning on the heater 4A) in the claims.

Then, from the count value of the timer,
Judge the elapse of the set time of 20 seconds (count up of 20 seconds)
(Step S_Five), When NO, the same set time is 20 seconds
Until the time elapses, the water heater 4A and the heater
4B ON state (step S ₃) And timer count
Action (Step S_Four) Is continued while YES (20 seconds
8), the time chart of FIG.
As shown in the table,
Both the heaters 4B are turned off (step S₆), The same
State determination control (step S₇).

This empty cooking determination control is performed as a subroutine, for example, as shown in the flow chart of FIG.

That is, first, based on the count value of the timer, a predetermined elapsed time of 40 seconds after the boiling water is started (the boiling water detection control is started) for detecting the hot water temperature required for the empty cooking determination. It is determined whether or not has passed (step S ₁ ). As a result, when the above-mentioned hot water temperature detection start time of 40 seconds has not elapsed for NO, once the control is finished,
Further, the elapse of 40 seconds is judged again.

On the other hand, when YES after the 40-second hot-water temperature detection start time has elapsed, the basic data T ₁ of the hot-water temperature detection value T (the first hot-water temperature detection value for the first time, which is the reference for determining the hot-water temperature rise rate, is determined. ) Is stored in memory (step S ₂ ).
This hot water temperature detection control is based on the hot water temperature detection start time (40 seconds).
After the lapse of time, a 2-second cycle is performed.

As a result of the judgment, at the first first hot water temperature detection timing of NO when the basic data T ₁ is not yet stored in memory, the hot water temperature on the lowest temperature side which becomes the basic data T ₁ is next set. It is detected by the bottom sensor 12 and input (step S ₃ ). Then, after that, the elapse of the hot water temperature detection cycle of 2 seconds is determined. On the other hand, the same basic data T ₁ already exists YES
In the case of (the second and subsequent hot water temperature detections), the hot water temperature detection as the basic data T ₁ (step S ₃ ) is not performed, and it is subsequently determined whether or not the hot water temperature detection cycle of 2 seconds has elapsed. Yes (step S ₄ ).

Next, in either case of step S ₃ or step S ₂ , the hot water temperature detection cycle 2 is performed.
When seconds have elapsed (YES at Step S _4), and inputs the detected new hot water temperature data Tn to be compared (step S
₅ ).

Then, correspondingly, the number n of hot water temperature detections every 2 seconds is counted (step S ₆ ).

Next, the newly detected hot water temperature data T
n is the previous data T_n-1Greater than or not, that is, hot water
Determine whether the temperature is changing in the rising direction (step
S ₇). As a result, if YES, the above step
S₆Set the hot water temperature detection count n every 2 seconds
It is determined whether or not the number of times is n times (for example, n = 10 times).
(Step S₈).

As a result, if the hot water temperature detected n times (10 times) every 2 seconds of YES is a change in the rising direction, the final hot water temperature of the nth time (10th time) is finally obtained. It is determined whether or not the temperature difference ΔT (ΔT = Tn−T ₁ ) between the data Tn (T ₁₀ ) and the first basic data T ₁ is equal to or greater than a predetermined set value ΔTs, and when YES (ΔT ≧ ΔTs ) for the first time determined as "empty cook" (step S _10).

On the other hand, unlike this, the current hot water temperature Tn is the previous hot water temperature Tn during the n hot water temperature detection periods.
_When the water supply of NO judgment is performed in step S ₇ which is smaller than _n-1, or there is a sufficient amount of water in the inner container 3,
If NO determination etc. In criterion ΔTs small steps S ₉ than when increase rate ΔT of the temperature of the hot water is cooked empty, without performing a blank cook the determination in step S _10, the empty drawing 5 cook determination End control.

After the determination of empty cooking is performed as described above, the process returns to step S _{7 and} thereafter of the flowchart of the main routine of FIG.

Then, subsequently, as a system,
Confirm that the empty cooking determination process is complete (step S
₈ ) and then, based on the determination data, make a final decision on whether the rice is cooked empty or not (step S ₉ ).

As a result, in the case of NO non-dry cooking determination, in addition to the heat-retaining heater 4B, the above-mentioned boiling water heater 4A is turned on again (energized state) to start boiling water at a high output again (step S). ₁₀ ). On the other hand, in the case of YES determination of idle cooking, the buzzer 56 notifies the user of idle cooking (step S ₁₁ ), and in addition to the above-mentioned turning off of the water heater 4A, the warming heater 4B is also turned on.
The to OFF also ends the control (step S _12).

As described above, the electric pot according to the second embodiment of the present invention has the inner container 3 capable of boiling water and retaining heat.
A boiling water heater 4A as a high-power first heating means for heating the inner container 3, a heat retention heater 4B as a low-power second heating means for heating the inner container 3, and the first heater Heating control means for controlling each of the boiling water heater 4A as the heating means and the heat retaining heater 4B as the second heating means, and the inner container 3 via the bottom of the inner container 3.
A bottom sensor 12 as a temperature detecting means for detecting the temperature of water in the inside; a temperature rising rate calculating means for calculating a rising rate ΔT of the temperature of the water detected by the bottom sensor 12 as the temperature detecting means; In an electric pot provided with a timer as a time measuring means for measuring an elapsed time from the start, and an empty cooking determination means for determining empty cooking of the inner container 3,
The air-boiled cooking determining means includes the boiling heater 4A and the heat retaining heater 4B as the first heating means immediately after the start of boiling.
Is energized for a predetermined time (20 seconds), and then both the water heater 4A as the first heating means and the heat retention heater 4B as the second heating means are turned off and the predetermined time (4
When the temperature increase rate ΔT at the time point (0 seconds) has elapsed is equal to or higher than a predetermined temperature increase rate ΔTs, it is configured to determine that the rice is cooked.

Therefore, in this configuration, the boiling water heater 4A serving as the first heating means first turns on only once immediately after the boiling starts, so that the boiling water heater is turned on as compared with the configuration (duty control) of the conventional example described above. , The number of times of ON / OFF of the relay contact for OFF is much reduced, and the durability and reliability of the relay contact and the water heater 4A are greatly improved. Also, relay contact opening / closing noise (ON / O
The amount of FF noise) generated is also reduced.

Further, in this configuration, unlike the case of the first embodiment, the hot water heater 4A as the first heating means is turned off, and at the same time, the heat retention heater 4B as the second heating means is turned off. Therefore, it becomes possible to further reduce the power consumption amount during the empty cooking determination time. Further, since the ON time of the boiling water heater 4A as the first heating means and the heat retention heater 4B as the second heating means is as short as 20 seconds, the damage to the inner container and the temperature detecting means at the time of empty cooking Also becomes smaller.

(Dry Cooking Detection Control According to Third Embodiment) Next, the flowchart of FIG. 9 and the time chart of FIG. 10 show the contents of the empty cooking detection control of the electric pot according to the third embodiment of the present invention. There is.

That is, in the control, when the power plug is first connected to the power circuit of the electric pot, the control is started by detecting the power plug.

Therefore, first, the microcomputer of the microcomputer control section determines whether or not the boiling control is started and the boiling is being performed (step S ₁ ). As a result, when NO,
Control ends as it is. On the other hand, when it is determined to be in the boiling water state of YES, it is subsequently determined whether or not the determination of empty cooking (executed only once in this system) has been completed (step S ₂ ). When the result of the determination is YES, as described above, the empty cooking determination main control suffices to be executed only once in terms of system design, and thus the present control is terminated. On the other hand, when the result of the determination is NO, that is, when the determination of empty cooking is not completed yet (when it is not performed once),
As shown in 0 time chart, first, only the heat insulating heater 4B in the ON (energized) to start the preheating of the inner container 3 at a low output (step S _3).

Then, subsequently, a timer for counting various set times such as a predetermined set time of 20 seconds sufficient for watching the temperature rise of the inner container 3 and a set time of 40 seconds for starting the hot water temperature detection control is counted. starting the operation (step S _4). This timer corresponds to the time measuring means for measuring the elapsed time from the start of boiling water (after boiling water and turning on the heater 4A) in the claims.

Thereafter, it is judged from the count value of the timer whether the set time of 20 seconds has elapsed (counting up of 20 seconds) (step S ₅ ). If NO, the heat retention is maintained until the set time of 20 seconds elapses. while continuing the oN state of the heater 4B (step S ₃₎ and the timer count operation (step S _4), becomes a YES (20 seconds elapses), as shown in the time chart of FIG. 10 upon elapse said 20 seconds,
Furthermore the high power boiler heater 4A to ON (Step S _6), heats the inner container 3 to balance kettle heater 4A and kept the heater 4B in a high output state which is to ON.

Thereafter, based on the count value of the timer, it is determined whether or not a predetermined time of 40 seconds has elapsed since the boiling of water was started (from the start of the idle cooking detection control) (step S ₇ As a result, when the hot water temperature detection start time of 40 seconds has not passed for NO, heating at the high output is continued until the hot water temperature detection start time of 40 seconds has passed.

On the other hand, YE after the predetermined time of 40 seconds has passed
When S is first dropped output to OFF of the kettle heater 4A (step S _8), then proceeds to the above-mentioned case (Fig. 5) similar to air and cook determination control (Step S _9).

Even in the case of the empty cooking determination control in this case,
Similar to the case of the embodiment, the flowchart of FIG.
Step S₁The setting time of is 40 seconds, and the same time
After 40 seconds have passed, only the above heat retaining heater 4B is turned on.
Then step S ₂From step S₈, S₉，
S_TenPerform the same process as above, and finally 6
Final hot water temperature data for the 10th time when 0 seconds has passed
T_TenAnd the first basic data T above₁Temperature difference ΔT (ΔT =
T_Ten-T₁) Is greater than or equal to a predetermined set value ΔTs
When the judgment is made and YES (ΔT ≧ ΔTs), “air cooking
It will be determined.

[0099] Thereafter, the process returns again to below steps S ₉ of the flowchart of the main routine of FIG. 9 described above, confirm that the air-cook determination process is terminated as a system in terms of (Step S ₁₀₎ was, on the determination data the final sky cook or non air-based cook verdict (step S _11).

[0100] As a result, in the case of non-empty cook determination of NO, in the above-described boiler heaters 4A and kept the heater 4B respectively again turned ON (energized) to start again kettle (step S _12). On the other hand, if the determination is YES, the buzzer 56 notifies the user of the idle cooking (step S ₁₃ ), and further turns off the boiling water heater 4A and the warming heater 4B. finish control (step S _14).

As described above, the electric pot according to the third embodiment of the present invention is the inner container 3 capable of boiling water and retaining heat.
A boiling water heater 4A as a high-power first heating means for heating the inner container 3, a heat retention heater 4B as a low-power second heating means for heating the inner container 3, and the first heater Heating control means for controlling each of the boiling water heater 4A as the heating means and the heat retaining heater 4B as the second heating means, and the inner container 3 via the bottom of the inner container 3.
A bottom sensor 12 as a temperature detecting means for detecting the temperature of water in the inside, a temperature increase rate calculating means for calculating an increase rate of the temperature of the water detected by the bottom sensor 12 as the temperature detecting means, and starting of boiling water. In an electric kettle provided with a timer as a time measuring means for measuring the elapsed time after that, and an empty cooking determining means for determining the empty cooking of the inner container 3, the empty cooking determining means is provided immediately after the start of boiling. Only for the heat retaining heater 4B as the second heating means, a predetermined time (20 seconds)
Electricity is supplied to preheat the same, and then the heat retention heater 4B as the second heating means is not turned off, and the boiling water heater 4A as the first heating means is further supplied with a predetermined time (20
Second) The power is turned on, and after that (when 40 seconds have passed since the start of boiling), only the boiling heater 4A as the first heating means is turned off. Then, after a lapse of a predetermined time (20 seconds), the heat retaining heater 4B as the second heating means is further turned off. Then, when the temperature increase rate ΔT at that time (60 seconds after the start of the water boiling) is equal to or higher than a predetermined temperature increase rate ΔTs, it is configured to determine “idling”. ing.

Therefore, in this configuration, at least first, the boiling water heater 4A as the first heating means is turned on only once after 20 seconds have elapsed from the start of boiling water. The number of times of ON / OFF is much reduced, and the boiling water heater ON / OFF relay contact, the boiling water heater 4A as the first heating means.
Durability and reliability are greatly improved. Also, relay contact opening / closing noise (OFF noise) does not occur.

Further, in relation to the energization time (60 seconds) of the heat retaining heater 4B as the second heating means, the energization time itself of the boiling water heater 4A as the first heating means is 20 seconds (or 20 seconds or less). ), It is possible to reduce the power consumption during the emptying determination time. As a result, the damage to the inner container 3 and the bottom sensor 12 which is the temperature detecting means at the time of empty cooking is reduced.

(Dry Cooking Detection Control According to Embodiment 4) Next, the flowchart of FIG. 11 and the time chart of FIG. 12 show the contents of the empty cooking detection control of the electric pot according to Embodiment 4 of the present invention. There is.

That is, in the control, when the power plug is first connected to the power circuit of the electric pot described above, it is detected and the boiling control is started.

Therefore, first, the microcomputer of the microcomputer control unit determines whether or not the boiling control is started and the boiling is being performed (step S ₁ ). As a result, when NO,
Control ends as it is. On the other hand, when it is determined to be in the boiling water state of YES, it is subsequently determined whether or not the determination of empty cooking (executed only once in this system) has been completed (step S ₂ ). When the result of the determination is YES, as described above, the empty cooking determination main control suffices to be executed only once in terms of system design, and thus the present control is terminated. On the other hand, when the result of the determination is NO, that is, when the determination of empty cooking is not completed yet (when it is not performed once),
As shown in the second timing chart, first, only the heat insulating heater 4B in the ON (energized) to start the preheating of the inner container 3 at a low output (step S _3).

Then, subsequently, a timer for counting various set times such as a predetermined set time of 20 seconds sufficient to see the temperature rise of the inner container 3 and a set time of 40 seconds for starting the hot water temperature detection control is counted. starting the operation (step S _4). This timer corresponds to the time measuring means for measuring the elapsed time from the start of boiling water or the like (after turning on the heat retention heater 4B or the boiling water heater 4A) in the claims.

Thereafter, it is judged from the count value of the timer whether the set time of 20 seconds has elapsed (counting up of 20 seconds) (step S ₅ ), and if NO, the heat retention is continued until the set time of 20 seconds elapses. while continuing the oN state of the heater 4B (step S ₃₎ and the timer count operation (step S _4), becomes a YES (20 seconds elapses), as shown in the time chart of FIG. 12 upon elapse said 20 seconds,
Furthermore the high power boiler heater 4A to ON (Step S _6), heats the inner container 3 both kettle heater 4A and kept the heater 4B in a high output state which is to ON.

Then, based on the count value of the timer, it is determined whether or not a predetermined time of 40 seconds has elapsed since the boiling of water was started (from the start of the empty cooking detection control) (step S ₇ ). As a result, when the hot water temperature detection start time of 40 seconds has not elapsed for NO, heating at the high output is continued until the hot water temperature detection start time of 40 seconds has elapsed.

On the other hand, YE after the predetermined time of 40 seconds has passed
When S is first heating was stopped and the both OFF the kettle heater 4A and insulation heater 4B (step S _8), then the same sky cook determination control and the above-mentioned case (Fig. 5) (Step S ₉₎ Proceed to.

Even in the dry cooking determination control in this case, the set time in step S ₁ of the flowchart in FIG. 5 is 40 seconds, and after the same time 40 seconds has elapsed, the boiling water heater 4A and the heat retaining heater 4B are further operated. in each OFF state, step S ₈ from step S ₂ described above, S _9, S ₁₀
6) from the start of boiling water
It is determined whether or not the temperature difference ΔT (ΔT = T ₁₀ −T ₁ ) between the final hot water temperature data T ₁₀ at the tenth time after 0 seconds and the first basic data T ₁ is equal to or greater than a predetermined set value ΔTs. Yes
When (ΔT ≧ ΔTs), it is first determined that the cooking is “idle cooking”.

[0112] Thereafter, the process returns again to below steps S ₉ of the flowchart of the main routine of FIG. 11 described above, confirm that the air-cook determination process is terminated as a system in terms of (Step S ₁₀₎ was, on the determination data the final sky cook or non air-based cook verdict (step S _11).

[0113] As a result, in the case of non-empty cook determination of NO, in the above-described boiler heaters 4A and kept the heater 4B respectively again turned ON (energized) to start again kettle (step S _12). On the other hand, if the determination is YES, the buzzer 56 notifies the user of the idle cooking (step S ₁₃ ), and further turns off the boiling water heater 4A and the warming heater 4B. finish control (step S _14).

As described above, the electric pot according to the fourth embodiment of the present invention is the inner container 3 capable of boiling water and keeping warm.
A boiling water heater 4A as a high-power first heating means for heating the inner container 3, a heat retention heater 4B as a low-power second heating means for heating the inner container 3, and the first heater Heating control means for controlling each of the boiling water heater 4A as the heating means and the heat retaining heater 4B as the second heating means, and the inner container 3 via the bottom of the inner container 3.
A bottom sensor 12 as a temperature detecting means for detecting the temperature of water in the inside, a temperature increase rate calculating means for calculating an increase rate of the temperature of the water detected by the bottom sensor 12 as the temperature detecting means, and starting of boiling water. In an electric pot provided with a timer as a time measuring means for measuring the elapsed time after that, and an empty cooking determining means for determining the empty cooking of the inner container 3, the empty cooking determining means firstly immediately after starting the boiling. In addition, only the heat retaining heater 4B serving as the second heating means has a predetermined time (20
For 2 seconds), and then the hot water heater 4A as the first heating means is energized for a predetermined time (20 seconds) without turning off the heat retaining heater 4B as the second heating means, and then the first heating is performed. Both the water heater 4A as a means and the heat retention heater 4B as a second heating means are turned off.
To Then, after that, when the temperature rise rate ΔT when a predetermined time (20 seconds) has passed (when 60 seconds have passed from the start of boiling) is equal to or higher than the predetermined temperature rise rate ΔTs, it is determined that the cooking is “idle cooking”. Is configured to do.

Therefore, in this configuration, at least the first
Since the hot water heater 4A as the heating means of the first embodiment turns on only once when a predetermined time of 20 seconds elapses after the start of hot water, the relay contact is turned on and off as compared with the conventional configuration.
The number of times of F is much reduced, and the heater is turned on and off.
Durability and reliability of the relay contact and the water heater 4A are greatly improved. Also, relay contact opening / closing noise (ON / O
The amount of FF noise) generated is also reduced.

Further, because of the relationship with the energization time (40 seconds) of the heat retaining heater 4B as the second heating means, the energization time itself of the water heater 4A as the first heating means can be shortened to 20 seconds. It is also possible to reduce the amount of power consumption within the determination time for empty cooking. As a result, the damage to the inner container 3 and the bottom sensor 12 which is the temperature detecting means at the time of empty cooking is reduced.

[Brief description of drawings]

FIG. 1 is a longitudinal central cross-sectional view in the front-rear direction as seen from the right side, showing the configuration of an electric pot main body portion common to each embodiment of the present invention.

FIG. 2 is a plan view of the electric pot body portion.

FIG. 3 is a control block circuit diagram of the electric pot main body portion.

FIG. 4 is a flow chart of a main routine showing the contents of idle cooking detection control according to the first embodiment of the present invention.

FIG. 5 is a flowchart of a sub-routine showing the contents of empty cooking determination control in the same empty cooking detection control.

FIG. 6 is a time chart showing the contents of the same boiled rice detection control.

FIG. 7 is a flowchart showing the contents of the empty cooking detection control according to the second embodiment of the present invention.

FIG. 8 is a time chart showing the contents of the same boiled rice detection control.

FIG. 9 is a flow chart showing the contents of idle cooking detection control according to the third embodiment of the present invention.

FIG. 10 is a time chart showing the contents of the same boiled rice detection control.

FIG. 11 is a flow chart showing the contents of idle cooking detection control according to the fourth embodiment of the present invention.

FIG. 12 is a time chart showing the contents of the same boiled rice detection control.

[Explanation of symbols]

1 is a container body, 2 is a lid, 3 is an inner container, 4A is a heater for boiling water, 4B is a heater for warming water, 5 is a hot water supply passage, 6 is an electric hot water supply pump, 7 is an outer case, 10 is an inner cylinder, and 11 is an outer cylinder. , 12
Is a bottom sensor (thermistor), 18 is a manual hot water pump, 4
Reference numeral 7 is a liquid crystal display unit, 47b is a heat retention set temperature display unit, 56 is a buzzer, and 60 is a microcomputer control unit.

Claims (5)

[Claims] 1. An inner container capable of boiling and retaining heat, a first heating means of high power for heating the inner container, a second heating means of low power for heating the inner container, and the first Heating means for controlling each of the heating means and the second heating means, a temperature detecting means for detecting the temperature of water in the inner container via the bottom of the inner container, and a temperature detecting means for detecting the temperature. Temperature increase rate calculating means for calculating the temperature increase rate of the water, a time measuring means for measuring the elapsed time from the start of boiling, and an empty cooking determining means for determining empty cooking of the inner container In the electric kettle configured as described above, the empty cooking determination means energizes the first heating means for a predetermined time immediately after starting boiling, and then turns off the first heating means for a predetermined time only in the second heating means. The temperature rise rate after energization is the specified temperature rise rate. An electric kettle characterized in that it is configured to determine that the rice is cooked empty when the above is the case. 2. The electric pot according to claim 1, wherein the energization time to the first heating means is shorter than the energization time to the second heating means. 3. An inner container capable of boiling and retaining heat, a first heating means of high power for heating the inner container, a second heating means of low power for heating the inner container, and the first Heating means for controlling each of the heating means and the second heating means, a temperature detecting means for detecting the temperature of water in the inner container via the bottom of the inner container, and a temperature detecting means for detecting the temperature. Temperature increase rate calculating means for calculating the temperature increase rate of the water, a time measuring means for measuring the elapsed time from the start of boiling, and an empty cooking determining means for determining empty cooking of the inner container In the electric kettle configured as described above, the empty cooking determination means energizes the first heating means for a predetermined time immediately after the start of boiling, and then turns off the first heating means to turn off the temperature increase rate after a predetermined time elapses. , When the temperature rises above a certain level An electric pot, characterized in that it is arranged to make a determination. 4. An inner container capable of boiling water and retaining heat, a first heating means of high power for heating the inner container, a second heating means of low power for heating the inner container, and the first Heating means for controlling each of the heating means and the second heating means, a temperature detecting means for detecting the temperature of water in the inner container via the bottom of the inner container, and a temperature detecting means for detecting the temperature. Temperature increase rate calculating means for calculating the temperature increase rate of the water, a time measuring means for measuring the elapsed time from the start of boiling, and an empty cooking determining means for determining empty cooking of the inner container In the electric pot configured as described above, the empty cooking determination means energizes only the second heating means for a predetermined time immediately after the start of boiling, and then the first heating means is turned on without turning off the second heating means. The means is also energized for a predetermined time, and then the first An electric pot, characterized in that when the temperature rising rate after a lapse of a predetermined time after turning off the heating means is equal to or higher than the predetermined temperature rising rate, it is determined that the cooking is performed in an empty state. 5. An inner container capable of boiling and retaining heat, a first heating means of high power for heating the inner container, a second heating means of low power for heating the inner container, and the first Heating means for controlling each of the heating means and the second heating means, a temperature detecting means for detecting the temperature of water in the inner container via the bottom of the inner container, and a temperature detecting means for detecting the temperature. Temperature increase rate calculating means for calculating the temperature increase rate of the water, a time measuring means for measuring the elapsed time from the start of boiling, and an empty cooking determining means for determining empty cooking of the inner container In the electric pot configured as described above, the empty cooking determination means energizes only the second heating means for a predetermined time immediately after the start of boiling, and then the first heating means is turned on without turning off the second heating means. Energize for a predetermined time, then first and second heating An electric pot characterized in that it is configured to determine that the cooking is performed when the temperature rise rate when the means is turned off is equal to or higher than a predetermined temperature rise rate.