JP2003265308A - Electric rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric rice cooker in which tasteful boiled rice can be speedily cooked by preventing bedewing on an inner pot and promoting the discharge of steam during rice cooking. <P>SOLUTION: In the rice cooker provided with the inner pot, a body case for housing the inner pot and a lid for covering the upper portion of the body to be freely opened/closed, the lid has an upper lid, a lower lid and an inner lid freely removably mounted on the lower lid and composed of a magnetic metal for covering an opening on the upper portion of the inner pot to be freely opened/closed. Then, the lower lid is provided with a heating coil for induction heating to the inner lid and between the heating coil and the inner lid, a non- magnetic metal is arranged for generating high frequency vibration on the inner lid. By electrifying the heating coil with a high frequency current in the respective processes of boiling, steaming and warmth retaining during rice cooking, the inner lid is heated and the high frequency vibration is applied to the inner lid. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric rice cooker capable of preventing dew on the inner surface of a lid and cooking delicious rice.

[0002]

2. Description of the Related Art As a conventional electric rice cooker having this kind of structure, there is one disclosed in Japanese Patent Laid-Open No. 9-122012, for example. FIG. 9 is a structural diagram of the main part of the rice cooker, in which a heating heater 32 and a high-frequency vibrating means 33 are provided inside a lid unit provided on the upper part of the rice cooker body, on a radiator plate 31 forming the lid portion of the inner pot. There is.

Then, as shown in FIG. 10, in a series of steps of water absorption, cooking, murmuring, and heat retention during rice cooking, particularly from the time just before the end of the muurashi stroke to the heat retention step, the heat dissipation plate is used. With the heating stopped, the high-frequency vibrating means is driven to vibrate the heat dissipation plate, and the droplets generated on the heat dissipation plate are evaporated and scattered back into the inner pot, so that the droplets on the rice Direct dropping is eliminated, and since the droplets can be returned to the rice again in a mist or vaporized state, it is possible to prevent yellowing, dryness, and white blur of the rice.

[0004]

However, according to such a conventional electric rice cooker, the high-frequency vibrating means is driven while the heating of the heat sink is stopped from the end of the purging stroke to the heat retention step. In the cooking process that produces the most water vapor in the processes of water supply, cooking, steaming, and heat retention during rice cooking, some of the water vapor condenses and condenses inside the heat sink, and these The rice that is being dripped on the surface of the rice is cooked and contains moisture again, which impairs the deliciousness. In addition, the boiling process takes a long time to boil the dropped water again, resulting in increased power consumption. There was a problem. The present invention has been made to solve such a problem, and prevents dew condensation on the inner lid in the cooking process in which most steam is generated during the rice cooking process from absorption of water to heat retention and promotes discharge of steam. Therefore, it is an object of the present invention to provide an electric rice cooker that is delicious and can be cooked in a short time.

[0005]

In order to achieve the above object, the present invention provides an inner pot, a main body case for accommodating the inner pot,
In an electric rice cooker having a lid that covers the upper part of the body case in an openable and closable manner, the lid is detachably attached to an upper lid and a lower lid and a lower surface of the lower lid to cover an upper opening of the inner pot. A non-magnetic metal having an inner lid made of a magnetic metal material, the lower lid being provided with a heating coil for inductively heating the inner lid, and generating high frequency vibration in the inner lid between the induction heating coil and the inner lid. A high-frequency current is passed through the heating coil in each step of arranging a material, cooking, steaming, and heat retention during rice cooking.

Further, in an electric rice cooker equipped with an inner pot, a main body case for accommodating the inner pot, and a lid body for opening and closing the upper portion of the main body case, the lid body includes an upper lid and a lower lid.
An inner lid made of a magnetic metal material is detachably attached to the lower surface of the lower lid to cover the upper opening of the inner pot, and a heating coil for induction heating the inner lid is provided on the lower lid. This heating coil is divided into an inner coil located on the center side of the lower lid and an outer coil located on the outer circumference side, and high-frequency current is applied to the inner coil and the outer coil in each step of cooking, steaming, and heat retention during rice cooking. Are energized in mutually different directions.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Embodiment 1 of the present invention will be described below with reference to the accompanying drawings. 1 is a vertical cross-sectional view showing the configuration of the electric rice cooker according to the first embodiment, FIG.
Is a bottom view of the lid, and FIG. 3 is a block diagram of the control system. In the figure, 1 is a main body case, 2 is an annular upper frame provided on the upper part of the main body case 1, and an inner frame 3 of a cylindrical shape having a bottom and hanging downward is formed on the inner periphery thereof. Reference numeral 4 denotes an inner pan stored in the inner frame, 4a denotes a flange provided on an upper edge of the inner pan 4, and the inner pan 4 is suspended from an upper end of the inner frame 3 by a flange 4a. 5 is the body case 1
Is a lid that covers the upper opening of the main body in a freely openable and closable manner. The button 7 is detachably locked.

Reference numeral 8 denotes a heating coil (hereinafter referred to as a bottom coil) for inductively heating the inner pot 4 provided outside the bottom of the inner frame 3.
Is a temperature sensor for the inner pot (hereinafter referred to as the bottom sensor) that comes into contact with the bottom of the inner pot 4 and detects its temperature, 10 is an operation control board, and 11 is an operation panel. The lid 5 is an upper lid 12, a lower lid 13, and an inner lid 14 which is detachably attached to the lower lid 13 and which is a magnetic metal material that covers the upper opening of the inner pot 4 in an openable and closable manner, for example, a stainless steel plate. Have and. Also,
There is a mounting portion 13a of a steam outlet 15 for discharging steam, which communicates with the inside of the inner pot, and the inner lid 14 is induction-heated around the steam outlet mounting portion 13a on the upper surface of the lower lid 13 at approximately the center of the lid 5. Ring-shaped heating coil 16 (hereinafter referred to as lid coil)
Is provided between the lid coil 16 and the inner lid 14 and is made of a ring-shaped non-magnetic material having a width smaller than the lateral width of the lid coil 16, for example, a magnetic flux modulation plate 17 made of copper, aluminum or the like. Is provided. Reference numeral 18 denotes a temperature sensor (hereinafter referred to as a lid sensor) provided in the lower lid 13 for detecting a boiling state inside the inner pot 4, and 19 heats the inner pot 4 provided outside the side portion of the inner frame 3. It is a body heater.

FIG. 3 is a block diagram of a control system in the electric rice cooker of the present invention. 20 is a rice cooking key for instructing the start of rice cooking, 21 is a heat retaining key for instructing heat retention, 22 is the rice cooking key 20, or A cancel key for instructing cancellation of the heat retention key 21, a control device for a rice cooker 23, key input determination means 23a for determining inputs from the rice cook key 20, the heat retention key 21, and the cancellation key 22, and the key input. Information of the determination means 23a, the bottom sensor 9, and the lid sensor 1
8 information, the bottom coil 8, the lid coil 16,
It is a control device that issues an operation command for the body heater 19, and includes, for example, a rice cooking program as shown in the flowchart of FIG. 4, and the temperatures of the bottom sensor 9 and the lid sensor 18 are set as shown in the time chart of the rice cooking characteristics shown in FIG. The energization control of the bottom coil 8, the lid coil 16, and the body heater 19 is performed in correspondence with each process of taking in, absorbing water, cooking, shaving, and retaining heat.

Next, the operation of the electric rice cooker according to the first embodiment will be described. FIG. 4 is a flow chart for explaining the operation, and FIG. 5 is a timing chart during rice cooking. In FIG. 4, in step S1, the key input determination means 23a determines whether or not the rice cooking key 20 is turned on. If NO (hereinafter referred to as N), the process proceeds to step S2, and it is determined whether the heat retention key 21 is turned on. At this time, if N, the process proceeds to step S3, and it is determined whether or not the cancel key 22 is turned on. If YE
If S (hereinafter referred to as Y), the process ends, and if N, the process returns to step S1.

If the rice cooking key 20 is Y in step S1, the process proceeds to step S4, in which the control means 23b continuously energizes the bottom coil 8 with a high-frequency current and enters the water absorption process shown in FIG.
In step 5, the bottom sensor 9 for detecting the bottom temperature of the inner pot 4
It is determined whether or not the temperature t has reached a preset water absorption temperature t1 (for example, 40 ° C.). If it is N, the process returns to step 4, and the ON state of the bottom coil 8 is continued. When the temperature t ≧ t1, the control means 23b determines in step 6 that
Intermittent energization is performed by turning on and off the bottom coil 8 at a preset time ratio so as to maintain the temperature t at t1.

In step 7, counting of the time T is started and a preset water absorption time T1 (for example, 20
Minutes), and if time T ≧ T1 is not satisfied, the process returns to step 6, and if time T ≧ T1, the process proceeds to step 8. In step 8, the control means 23b causes the bottom coil 8
Is continuously energized, and the cooking process shown in FIG. 5 begins. In this process, the temperature in the inner pot 4 starts to rise, and the temperature t of the lid sensor 18 also rises.

In step 9, the temperature t of the lid sensor 18
Is set to a preset boiling temperature t2 (for example, 100
℃) is reached. If the temperature is not t ≧ t2, the process returns to step 8, and if the temperature is t ≧ t2, the process proceeds to step 10. In step 10, the control means 23b switches the bottom coil 8 to ON / OFF intermittent energization control at a preset time ratio, and turns ON / OFF the high frequency current to the lid coil 16 at a preset time ratio.
Then, the intermittent energization control is started. When boiling starts, inner pot 4
As the water vapor is generated inside, the internal pressure rises,
Ejection of water vapor starts from the steam port 15.

An alternating magnetic field is generated in the lid coil 16 by the application of a high frequency current, the inner lid 14 made of a magnetic metal material generates heat, and the alternating magnetic field is a magnetic flux modulating plate 17 made of a non-magnetic metal material. And the high frequency vibration is excited in the inner lid 14 facing the magnetic flux modulation plate 17. As a result, the inner lid 14 is broken line A shown in FIG.
And high frequency alternating vibration like B is performed. That is, since the inner lid 14 is heated while vibrating at high frequency, among the water vapor generated in the inner pot 4 and filling the inside, the water vapor approaching the inner lid 14 is scattered as finer water vapor by the high frequency vibration. Since the inner lid 14 is heated, the inner lid 1
Water vapor that touches 4 does not condense on the inner lid surface,
Discharge from the steam port 15 is promoted, and water drops do not drip on the rice.

In step 12, when the boiling state continues and the water content decreases, the temperature t of the bottom sensor 9 rises sharply, and the control means 23b causes the preset cooking temperature t3.
(For example, 130 ° C.) is determined. If the temperature is not t ≧ t3, the process returns to step 10 and the lid coil 1
The intermittent energization control to 6 is continued. When the temperature t ≧ t3, the process proceeds to step 13. In step 13, the control means 23b turns off the power supply to the bottom coil 8 and the lid coil 16.
Then, the cooking process is completed.

In step 14, the temperature t of the bottom sensor 9 starts to decrease, and the control means 23b determines whether or not the preset uneven temperature t4 (for example, 110 ° C.) has been reached. Then, when the temperature becomes t ≦ t4, the process proceeds to step 15 and enters the purging stroke. In step 15, the control means 2
3b turns on the bottom coil 8 at a preset time ratio
-OFF intermittent energization control, high-frequency current is turned on and off in the cover coil 16 at a preset time ratio, intermittent energization control is restarted, and the temperature t4 is maintained.

In step 16, the control means 23b starts counting the time T and judges whether or not the preset steaming time T2 (for example, 10 minutes) has been reached. If the time T ≧ T2 is not satisfied, the process proceeds to step 15. Return, time T ≧
When T2 is reached, the process proceeds to step 17. In this Murashiri stroke, the amount of water vapor generated per se is less than in the cooking stroke, but the steam generated in the inner pot 4 is heated as the inner lid 14 vibrates at high frequency as in the cooking stroke. The inner lid 1 is generated in the steam generated in the pan 4 and filling the inside.
The steam approaching 4 is scattered by the high frequency vibration as finer steam, and since the inner lid 14 is further heated, the steam touching the inner lid 14 does not condense on the surface of the inner lid, and the steam port 15 Emission of water is promoted.

In step 17, the control means 23b turns off the energization of the bottom coil 8 and the lid coil 16, and step 18
Proceed to the heat retention process. In step 18, the temperature is lowered by turning off the energization of the bottom coil 8 and the lid coil 16. The temperature t of the bottom sensor 9 determines whether or not the control means 23b has reached a preset heat retention temperature t5 (for example, 70 ° C.). If t ≦ t5, the process proceeds to the heat retention step of step 19.

In step 19, the control means 23b turns on / off the bottom coil 8 at a preset time ratio for intermittent energization, and turns on / off a high frequency current to the lid coil 16 at a preset time ratio. While the intermittent energization control is restarted, the body heater 19 also performs the ON-OFF intermittent energization control at a preset time ratio to maintain the temperature t5. In this heat retention process, the amount of water vapor generated is much smaller than in the steaming process,
As with the steaming process, the water vapor generated in the inner pot 4 is the inner lid 14
Is heated while vibrating at high frequency, the steam that is generated in the inner pot 4 and approaches the inner lid 14 is scattered as finer water vapor by the high frequency vibration in the steam filling the inside, and the inner lid 14 is Since it is heated, the steam that rises and comes into contact with the inner lid 14 is expelled from the steam port 15 without dew condensation on the surface of the inner lid.

In step 20, when the temperature t of the bottom sensor 9 reaches the heat retention temperature t5, the power supply to the bottom coil 8, the lid coil 16 and the body heater 19 is turned off. As a result, in step 21, the temperature of the bottom sensor 9 becomes lower than the heat retention temperature t5, and when the cancel key 22 is not pressed in step 23, the process returns to step 19 and the heat retention process is continued. When the cancel key is operated in step 23, the control means 23b ends the heat retention process and the rice cooking process based on the determination made by the key input determination means 23a. Further, in step 2, when the heat retention key is operated, the control means 23b proceeds to the heat retention step of step 18 based on the determination by the key input determination means 23a.

Embodiment 2. Next, the electric rice cooker according to the second embodiment will be described. FIG. 7 is a vertical sectional view showing the overall configuration of the electric rice cooker according to the second embodiment, and FIG. 8 is a plan view of the electromagnetic induction coil of the same. In the figure, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. On the upper surface of the lower lid 13, the steam port mounting portion 1
The electromagnetic induction coil 16 disposed around 3a, that is, the lid coil, includes an inner coil 16a located on the center side of the lower lid 13 and an outer coil 16b located on the outer circumferential side with a predetermined distance from the inner coil 16a. Is divided into The inner coil 16a and the outer coil 16b have substantially the same number of turns and are wound in opposite directions, as shown in FIG.

In such a structure, the inner coil 16a
When a high-frequency current is applied to the outer coil 16b and the outer coil 16b, the inner lid 14 generates heat due to the action of the magnetic field, and the inner coil 16a and the outer coil 16b are wound in opposite directions. Conversely, by this action, high frequency vibration is induced in the inner lid 14 as in the first embodiment. Therefore, as in the case of the first embodiment, it is possible to realize the operation in each process of cooking, steaming, and heat retention.

That is, since the steam generated in the inner pot 4 is heated while vibrating the inner lid 14 at high frequency, the steam generated in the inner pot 4 and approaching the inner lid 14 among the steam filling the inside. Is scattered as finer water vapor by high frequency vibration, and the inner lid 14 is further heated. Therefore, the water vapor that rises and comes into contact with the inner lid 14 does not condense on the inner lid surface and is discharged from the steam port 15. Since it is promoted, it is possible to cook the rice deliciously and in a short time without dripping water drops on the rice, prevent discoloration and odor of the rice, and keep the rice warm.

[0024]

As described above, the electric rice cooker of the present invention has the following effects.

That is, according to the invention of claim 1, in the electric rice cooker comprising an inner pot, a main body case for accommodating the inner pot, and a lid body which covers the upper portion of the main casing in an openable and closable manner, the lid The body has an upper lid and a lower lid, and an inner lid made of a magnetic metal material that is detachably attached to the lower surface of the lower lid and covers the upper opening of the inner pot, and the lower lid is heated by induction heating. In addition to providing a heating coil, a non-magnetic metal material that generates high-frequency vibration is placed between the heating coil and the inner lid, and high frequency is applied to the heating coil in each step of cooking, steaming, and heat retention during rice cooking. Because it carries current,
Water vapor generated in each process of cooking, steaming, and heat retention during rice cooking does not condense on the surface of the inner lid, and discharge from the steam outlet is promoted, so it is possible to prevent water droplets from dripping on the cooked rice. , The rice can be delicious and can be cooked quickly.

According to the invention of claim 2, an inner pot,
In an electric rice cooker that includes a main body case that stores this inner pot and a lid that covers the upper part of the main body case so that it can be opened and closed,
The lid body has an upper lid and a lower lid, and an inner lid made of a magnetic metal material that is detachably attached to the lower surface of the lower lid and covers the upper opening of the inner pot, and the lower lid has the inner lid. In addition to providing a heating coil for induction heating, the heating coil is divided into an inner coil located on the center side of the lower lid and an outer coil located on the outer circumference side, and each process of cooking, steaming, and heat retention during rice cooking is performed. Since high frequency current is applied to the inner coil and the outer coil in different directions, the steam generated during each step of cooking, steaming, and heat retention does not condense on the surface of the inner lid, Since the discharge of water is also promoted, it is possible to prevent water droplets from dripping on the rice and cook the rice deliciously and quickly.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an electric rice cooker according to a first embodiment of the present invention.

FIG. 2 is a bottom view of a lid of the electric rice cooker.

FIG. 3 is a block diagram of the control system.

FIG. 4 is a flowchart of the same operation.

FIG. 5 is a time chart of the same rice cooking characteristics.

FIG. 6 is a high frequency vibration mode of the inner lid.

FIG. 7 is a vertical sectional view showing an electric rice cooker according to a second embodiment of the present invention.

FIG. 8 is a plan view of the electromagnetic induction coil.

FIG. 9 is a sectional view of a main part of a conventional electric rice cooker.

FIG. 10 is a time chart of the rice cooking characteristics.

[Explanation of symbols]

1 body case, 2 frame, 3 inner frame, 4 inner pot, 5
Lid, 6 hinges, 7 locking button, 8 heating coil, 9
Inner pot temperature sensor, 10 operation control board, 11 operation panel, 12 upper lid, 13 lower lid, 13a mounting portion, 1
4 inner lid, 15 steam port, 16 lid coil, 16a inner coil, 16b outer coil, 17 magnetic flux modulation plate, 18 lid sensor, 19 body heater, 20 rice cooking key, 21 heat retention key, 22 cancel key, 23 control device,

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Sadao Kanaya             1728 Omaeda, Hanazono-cho, Osato-gun, Saitama 1728               Within Mitsubishi Electric Home Equipment Co., Ltd. F-term (reference) 3K051 AA08 CD43                 3K059 AA08 CD72                 4B055 AA05 BA62 CA24 CA71 CB27                       CC04 DA02 DA05 DB14 FA16                       FB11 FC06

Claims (2)

[Claims] 1. An electric rice cooker comprising an inner pot, a main body case for accommodating the inner pot, and a lid body that covers the upper portion of the main body case in an openable and closable manner, wherein the lid body includes an upper lid and a lower lid. An inner lid made of a magnetic metal material that is detachably attached to the lower surface of the lower lid and covers the upper opening of the inner pot, and the lower lid is provided with a heating coil for induction heating the inner lid, and the induction heating A non-magnetic metal material that generates high-frequency vibrations is arranged between the coil and the inner lid, and high-frequency current is applied to the heating coil in each step of cooking, steaming, and heat retention during rice cooking. An electric rice cooker characterized by that. 2. An electric rice cooker comprising an inner pot, a main body case for accommodating the inner pot, and a lid body that covers the upper portion of the main body case so as to be openable and closable, wherein the lid body includes an upper lid and a lower lid. An inner lid made of a magnetic metal material that is detachably attached to the lower surface of the lower lid and covers the upper opening of the inner pot, and a heating coil for induction heating the inner lid is provided on the lower lid,
This heating coil is divided into an inner coil located on the center side of the lower lid and an outer coil located on the outer circumference side thereof, and the inner coil and the outer coil are respectively separated from each other in each process of cooking, steaming, and heat retention during rice cooking. An electric rice cooker characterized in that a high-frequency current is applied in different directions.