JP3168518B2 - rice cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating type rice cooker.

[0002]

2. Description of the Related Art FIG. 4 is a diagram illustrating the configuration of a conventional rice cooker disclosed in Japanese Patent Application Laid-Open No. 1-265480. In FIG. 4, 31 is a pot, 32 is a heat retention heater, 33 is an induction heating coil, 34 is an outer lid, and 35 is an inner lid. Heating heater 3
2 comprises a side heater 32a and a lid heater 32b.

In a conventional rice cooker having such a configuration,
When the rice cooking process is completed and the warming process is started, the light emitting diode of the display unit lights up to indicate the warming process. Then, the pot 31 is heated by the induction heating coil 33 with power smaller than the input power at the time of cooking rice to keep the temperature. When the temperature of the pot 31 is higher than the heat retention temperature, the power supply to the heat retention heater 32 and the induction heating coil 33 is stopped. When the temperature of the pan 31 is lower than the heat retention temperature, the heat retention heater 32 and the induction heating coil 33 are alternately or simultaneously turned on and off at a low temperature every predetermined time to keep the temperature.

[0004]

As described above, in the conventional rice cooker, the induction heating coil 33 for the induction heating is mounted near the bottom of the pot 31, and the upper side of the pot 31 and the outer lid 3 are connected.
4, a side heater 32a and a lid heater 32b are provided. Therefore, the pot 31 is heated by the radiant heat of the resistance wire.
And an induction heating coil 33 that generates heat in the magnetic pot 31 by eddy current generated by an electromagnetic induction action, and the component serving as a heating source for heating the rice cooking material is 2. Kinds are used. Therefore, not only will the number of parts be increased by using members of different materials for related parts such as mica used for electric heating and ferrite used for induction heating, but also
Since the assembling and adjustment methods are different, the number of manufacturing steps increases accordingly.

At the bottom of the pot 31, Joule heat is generated by the eddy current generated by the induction heating coil 33, and the pot 31 itself serves as a heating source to directly heat the rice-cooking material. On the side and upper part of the pot 31, since the heat of the side heater 32a and the lid heater 32b indirectly heats the rice cooked material through the pot 31 or the inner lid 35, the heating efficiency is lower than that of the bottom of the pan 31, As a result, a temperature difference occurs between the bottom and the top of the pan 31, causing uneven heating of the cooked rice,
At the time of heat retention, there was a problem that dew easily adhered to the inner lid 35.

The present invention has been made in order to solve the problems of the conventional rice cooker, and the number of parts is reduced by using a common heating source for cooking rice and for keeping heat, thereby reducing the number of manufacturing steps. This prevents a malfunction of the electronic component on the operation board provided in the outer lid 2 due to a rise in temperature, thereby realizing a rice cooker free from failure. Also,
An object of the present invention is to provide a rice cooker capable of reducing uneven heating of cooked rice materials and preventing dew condensation.

[0007]

A body Means for Solving the Problems], and outer hook of a bottomed cylinder with a built-in body, is takeout freely housed in the outer hook, made of a magnetic material to put cooking material inside a bottomed cylindrical Inner pot,
An outer lid that opens and closes the upper opening of the inner hook, the gap to the inner surface of the outer lid
An inner lid made of a magnetic material detachably mounted with
A bottom coil for induction heating at least the bottom of the inner pot, an upper coil for induction heating the inner lid, and an operation board for rice cooking operation, and the bottom coil is disposed on the outer periphery of the outer pot facing the bottom of the inner pot. And the top coil in the bottom of the outer lid facing the inner lid
With a space around the top coil
Then, the operation board is placed in the upper portion of the outer lid and the upper surface coil.
It is housed so as to be located above the space .

[0008]

When the start key is pressed, the switch is turned on and the heating coil is energized. The energization excites the bottom coil and the side coil, and the generated alternating magnetic flux links the inner pot to generate Joule heat. Joule heat is also generated in the inner lid by the magnetic field generated by the upper coil. The heat generated in the inner pot and the inner lid by the electromagnetic induction action starts to heat the water in the inner pot from the entire surface.

[0009] Cooking of rice starts by heating the water in the inner pot.
It is controlled around ℃. At a certain time, the heating coil becomes O
It becomes N and it is switched to high heat heating. The heating of the high heat raises the temperature of the water and cooks the rice. When the water boils, it moves to a low heat, and when the amount of water decreases, the heating power is further reduced. When the water content in the inner pot disappears due to boiling, the temperature rises rapidly and at about 130 ° C., the energization of the heating coil is automatically stopped. After that, it enters the mustard process and cooks twice, then moves to the heat retention process by heating over low heat and cooks the rice.

[0010]

Embodiment 1 FIG. 1 is an explanatory view of the configuration of Embodiment 1 of the present invention, and FIG. 2 is a block diagram of Embodiment 1 of the present invention. In FIGS. 1 and 2, FIG.
The same reference numerals are given to the same parts as those of the conventional apparatus shown in FIG.

In FIG. 1, 1 is a rice cooker main body, and 2 is an outer lid. 3 is a hinge of the outer lid 2, 4 is a latch, 5 is a push button, and 6 is a steam cylinder. When the push button 5 is pressed, the latch 4 is released, the outer lid 2 rotates about the hinge 3 as a fulcrum, and the inside of the main body 1 is opened. Reference numeral 7 denotes an operation unit, 8 denotes an operation board, 9 denotes operation keys such as a start key and a cancel key, and 10 denotes an inner cover made of a magnetic material which is detachably mounted with a gap provided on the inner surface of the outer cover 2. The operation board 8 is accommodated in an upper part in the outer lid 2 and above a space of an upper surface coil 24 described later. The operation board 8 includes a liquid crystal display and an LED.
Alternatively, electronic components such as switches are mounted, and the switches are opened and closed by operating the operation keys 9. In particular, the same metal material as the outer layer member of the inner pot described below is used for the inner lid 10 of the present invention.

Reference numeral 11 denotes a heat-resistant outer pot which is a non-magnetic material fixed in the main body 1, and 12 denotes an inner pot. The inner pot 12 is made of, for example, a two-layer clad material in which different metals are polymerized on the inner and outer surfaces, and an iron-based material having high magnetic permeability and high electric resistance is used on the outer layer member side. The inner layer member of the inner pot 12 is made of aluminum or the like having high heat conductivity. The inner pot 12 is thermally bonded by bringing the inner and outer layers into close contact with each other, a display body indicating a water level line or the like is displayed on the inner surface, and a coating layer of a non-affinity substance such as Teflon (trade name) is displayed on the surface. It is formed.

13 is a temperature sensor, 14 is a power supply board, 15
Is a code reel, and 16 is a power plug. An upward force is applied to the temperature sensor 13 by a spring (not shown), and the temperature sensor 13 constantly contacts the inner pot 12 accommodated in the main body 1 to detect the rice cooking temperature. An electronic circuit for obtaining a constant DC voltage is incorporated in the power supply board 14, and a control unit 18 including a CPU, a timer, and a microcomputer having a memory function is also mounted.

Reference numeral 20 denotes a heating coil. 21 is a bottom coil constituting the main heating source Hm, 22 and 23 are sub-heating sources Hs
And three coils 21
To 23 are connected in series to form a heating coil 20. The bottom coil 21 has a large number of turns and is divided into two parts, a bottom surface and a peripheral edge of the outer kettle 11, and mainly contributes to rice cooking by inductively heating the bottom side surface of the inner kettle 12 with a high heating amount. The side coil 22 and the upper coil 23 having a small number of turns are provided on the side surface of the inner hook 12 and on the outer periphery of the outer hook 11 opposed to the shoulder of the inner hook 12, that is, near the outer periphery of the opening.
The side surface 2 and the inner lid 10 generate heat to mainly fulfill the function of keeping heat.

Numeral 24 denotes a top coil belonging to the sub-heating source Hs, which is disposed at the bottom in the outer cover 2 and which surrounds the top coil.
Is provided with a space . Since the upper surface coil 24 is disposed close to the inner lid 10 with a slightly increased number of turns, the amount of heating applied from the upper surface is increased,
Cooking rice material is effectively heated. As described above, with the installation of the upper coil 23 and the upper coil 24, the amount of heating from the upper surface during rice cooking becomes stronger in accordance with the amount of heating of the bottom coil 21, and cooking unevenness can be eliminated. In particular, there is an advantage that water droplets adhered to the inner surface of the inner lid 10 are evaporated by heating during the heat retaining step, so that the water drops can be prevented from flowing into the cooked rice.

Reference numeral 26 denotes a coil base made of an insulating material, and 27 denotes a plurality of ferrites arranged radially. Although not shown in detail, each of the heating coils 21 to 23 is spirally and spirally wound, held by the coil base 26, and positioned and attached to the outer surface of the outer shuttle 11. Further, the ferrite 27 prevents the magnetic flux from leaking from the bottom coil 21 and concentrates the magnetic flux on the inner pot 12 side for effective induction heating. W is water in the inner pot 12, and r is rice.

The reservation rice cooking operation of the embodiment of the present invention having such a configuration will be described below. Rice r and water w
, And then set in the main body 1, cover the inner lid 10, and close the outer lid 2. Next, the user pulls out the cord from the cord reel 15, connects the power plug 16 to a 100 V power outlet, and operates the operation keys 9 while watching the display on the operation unit 7 on the upper surface of the outer lid 2 to reserve a meal time. Set.

When the time has elapsed and the rice cooking start time corresponding to the reserved meal time has come, the timer of the control unit 18 operates to turn on the switch, and the heating coil 20 is energized. An excitation current of about 20 to 40 KHZ flows through the bottom coil 21 and the side coil 22 of the heating coil 20 due to the energization, and the generated alternating magnetic flux links the inner pot 12 to generate Joule heat based on the eddy current. Similarly, Joule heat is generated in the inner lid 10 by the magnetic field generated by the upper coil 23 and the upper coil 24. The heat generated in the inner pot 12 and the inner lid 10 by such an electromagnetic induction action heats the water w inside the inner pot 12 from the entire surface. At the same time, detection of the temperature of the temperature sensor 13 is started.

Cooking rice starts by heating the water w in the inner pot 12,
In the preheating step, the rice cooking temperature is controlled to approximately 40 ° C. by the ON / OFF operation of the heating coil 20 of the control unit 18. At time t2, the heating coil 20 is turned on, and the heating coil 20 is switched to high heat heating. The temperature of the water w inside rises due to high-heat heating, and the generated steam is released from the steam cylinder 6 to the atmosphere. When cooking rice proceeds and water w boils at 100 ° C, it is transferred to low heat,
As the amount of water in the inner pot 12 decreases, the heating power is further reduced.

When the water in the inner pot 12 is exhausted, the temperature rises sharply, and when the temperature reaches 130.degree.
By 8, the energization of the heating coil 20 is automatically stopped, and the process shifts to the washing process. After cooking twice at time t6 of the mustard process, the process is shifted to low heat heating for heat retention. The ON / OFF operation of the heating coil 20 corresponding to each step of rice cooking is as shown in FIG.

In the above embodiment, the four coils 21
The heating coil 20 in which the heating coils 20 to 24 are connected in series has been described as an example. Of the four coils, only the side coil 22, the upper coil 23, and the upper coil 24 may be connected in series, any combination, or all four coils May be connected in parallel, and each may be independently controlled by the control unit.

[0022]

According to the present invention, a body, and an outer hook of a bottomed cylinder with a built-in body, is takeout freely housed in the outer hook, made of a magnetic material to put cooking material inside a bottomed cylindrical setting the inner hook, an outer lid that opens and closes the upper opening of the inner hook, a gap on the inner surface of the outer lid
An inner lid made of a magnetic material detachably attached to the inner pot, a bottom coil for induction heating at least the bottom of the inner pot, an upper coil for induction heating the inner lid, and an operation board for rice cooking operation, The coil is placed on the outer periphery of the outer pot facing the bottom of the inner pot, and the top coil is placed on the bottom inside the outer lid facing the inner lid.
Space around the top coil and
The work board is located in the upper part of the outer lid and in the space of the upper coil.
The rice cooker housed so as to be located above was configured.

As a result, according to the present invention, since a heating source based on a different heating principle is not used unlike a conventional rice cooker, the same material can be used for related parts, and the number of parts can be significantly reduced. can do. In addition, the assembling and adjustment methods are almost the same, so that the adjustment work is also easy, and accordingly the number of manufacturing steps is reduced and the manufacturing cost can be further reduced. Further, since the rice cooked material is directly heated by the inner pot and the inner lid, the heating efficiency is good and the uneven heating is reduced.

Further, since the inner lid generates heat, the space between the upper portion of the inner pot, the upper surface of the inner lid, and the bottom surface of the outer lid is also heated,
Dew can be prevented during warming. Also provided outside the outer lid
The inner lid is used as a heat source, and the upper coil is connected to the inner surface of the outer lid.
At the bottom of the outer lid facing the inner lid mounted with a gap
Since a space is provided around the top coil and
The heat of the inner lid generated by the surface coil is
Is reduced by the heat shielding effect of the gap between
As well as inside the outer lid where temperature rise is prevented.
Located at the top and above the space around the top coil
The operation board is stored in such a way that
The heat shielding effect of the enclosed space prevents the temperature of the operation board from rising.
The electronic components and the like mounted on the operation board can be prevented from malfunctioning or malfunctioning.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a configuration of a first embodiment of the present invention.

FIG. 2 is a block diagram of Embodiment 1 of the present invention.

FIG. 3 is an operation explanatory diagram of the first embodiment of the present invention.

FIG. 4 is a diagram illustrating the configuration of a conventional rice cooker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Outer lid 7 Operation part 8 Operation board 9 Operation key 10 Inner lid 11 Outer pot 12 Inner pot 13 Temperature sensor 14 Power supply board 16 Power plug 18 Control part 20 Heating coil 21 Bottom coil 22 Side coil 23 Upper coil 24 Top coil Hm Main heating source Hs Secondary heating source W Water r Rice

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-4-58492 (JP, A) JP-A-63-63416 (JP, A) JP-A-63-63417 (JP, A) JP-A-5-634 68634 (JP, A) JP-A-6-84126 (JP, A) JP-A-53-58871 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) A47J 27/00

Claims (1)

(57) [Claims] [1 claim: a body, a bottomed cylindrical outer rotary hook incorporated in the body, is takeout freely accommodated in the outer pot, bottomed cylindrical inner hook made of a magnetic material to put cooking material therein When the outer lid that opens and closes the upper opening of the inner pot, which is removably mounted to provide a gap on the inner surface of the outer lid magnetic
An inner lid made of a material, a bottom coil for induction heating at least a bottom surface of the inner pot, an upper coil for induction heating the inner lid, and an operation board for rice cooking operation. The upper coil is disposed on the outer periphery of the outer hook facing the bottom, the upper coil is disposed on the bottom of the outer lid facing the inner lid, and the upper coil is vacant around the upper coil.
A space is provided, and the operation board is
And located above the space of the upper surface coil.
A rice cooker characterized by being stored like a rice cooker.