JPH06121732A - rice cooker - Google Patents

Abstract

(57) [Summary] [Purpose] A compact rice cooker is provided in which the inner pot is formed of a ceramic heater and the inner pot itself generates heat to reduce the heat source installation space. [Structure] In a rice cooker comprising a cooker main body, an inner pan 4 which is detachably accommodated in the cooker main body, and a lid 2 which covers the cooker main body in an openable and closable manner, the inner pan 4 is made of ceramic. A power supply circuit is provided which is formed by a heater and supplies power to the ceramic heater of the inner pot. Further, the rice cooker is provided with a lid switch that shuts off the power feeding circuit when the lid is opened. Further, the rice cooker is provided with an inner pot detection switch that shuts off the power supply circuit when the inner pot is taken out. Further, the rice cooker further comprises a control means for measuring the heater resistance value of the inner pot and controlling the energization of the heater based on the measured heater resistance value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat retention type rice cooker for keeping the cooked rice warm after cooking, and more particularly to a ceramic heater rice cooker having an inner pot made of ceramic heater.

[0002]

2. Description of the Related Art A heat-retaining rice cooker cooks rice by heating the bottom of an inner pot made of aluminum with a hot plate in which a heater is embedded.
It is common to have a structure in which heat is kept by a heat-retaining heater disposed on the side and / or the bottom of the inner pot. (For example, fairness 2
Further, an electromagnetic rice cooker in which an induction heating coil directly heats a bottom portion of an inner pot made of a magnetic material, such as an iron, has been commercialized and attracts attention.

On the other hand, in recent years, the effect of far infrared rays has been attracting attention in the field of cooking, and in order to cook the whole rice from inside, the inner pot is made of a ceramic material that emits a large amount of far infrared rays and is made of metal. A rice cooker having an outer surface provided with a protective layer has been proposed. (Actual Kaihei 1-5952
(See No. 8)

[0004]

In the above-mentioned heat-retaining type rice cooker, whether it is hot plate type heating or electromagnetic induction type heating, the inner pot is partially heated to cook rice and keep heat. It was felt that there was a limit to the improvement of rice cooking and heat retention performance.

On the other hand, in the rice cooker disclosed in Japanese Utility Model Publication No. 1-59528, the heating source is a gas stove, but since the rice cooker and the heat are kept by partially heating the inner pot, The same can be said for improvement. or,
In both the former and the latter, a heat source device (in the case of electromagnetic induction type heating, an electromagnetic induction heating coil is required separately from the inner pot, and the installation space of the heat source device has been a factor that reduces the volumetric efficiency of the rice cooker.

[0006]

In order to solve the above-mentioned problems, the rice cooker main body, an inner pot to be housed in the rice cooker main body, and a lid for covering the rice cooker main body in an openable and closable manner are provided. In the rice cooker, the inner pot is formed of a ceramic heater, and a power supply circuit for supplying power to the ceramic heater of the inner pot is provided.

Further, the rice cooker is provided with a lid switch that shuts off the power feeding circuit when the lid is opened.

Further, the rice cooker is provided with an inner pot detection switch which shuts off the power supply circuit when the inner pot is taken out.

Furthermore, in the above rice cooker, the inner pot heat
The resistance value is measured and the heat resistance is measured based on the measured heater resistance value.
A control means for controlling the energization of the power supply is provided.

[0010]

[Function] The inner pot formed of the salamic heater self-heats and becomes a heat source, and a large amount of far infrared rays are radiated from the inner pot to wrap it around the material (rice) in the inner pot. Further, when the lid is opened, the circuit for feeding power to the ceramic heater is cut off by the lid switch, and the receiving / feeding terminal (exposed energizing portion) of the ceramic heater is brought into a power failure state (inactive electricity state).

Furthermore, when the inner pot is taken out, the circuit for supplying power to the ceramic heater is cut off by the inner pot detection switch, and the receiving / supplying terminal (exposed energizing portion) of the ceramic heater is cut off.
Is in a power failure state (inactive state).

Furthermore, the temperature of the entire inner pot is detected by measuring the resistance value of the ceramic heater, and the heater energization control of the rice cooking operation and the heat retention operation is performed based on the resistance value (temperature).

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. 1 is a sectional view of a rice cooker showing an embodiment of the present invention, and FIG. 2 is a basic electric circuit diagram of the rice cooker. The heat-retaining type rice cooker is roughly composed of an outer pot 1, an outer lid 2, an inner lid 3, an inner pot 4 and the like.

The outer pot 1 has an inner wall body 1a and an outer wall body 1b made of metal such as stainless steel, which are connected to each other to form both wall bodies 1a,
A heat insulating material 5 is loaded between 1b. On the inner bottom surface, projecting support portions 1c for supporting the inner pot 4 at three points are formed by bulging the inner wall body 1a, and one inner projecting support portion 1c is closely attached to the outer bottom surface of the inner pot. A temperature sensor 6 for detecting the temperature of the bottom of the inner pot 4 is built in. Further, the projecting support portion 1c is provided with an impact buffer 7 made of a heat-resistant elastic material such as silicon rubber to alleviate the impact on the temperature sensor 6 and the inner pot 4 when the inner pot 4 is stored.

On the other hand, a plurality of supporting legs 8 and a cord reel 9 are attached to the outer bottom surface, and an operation panel 10 is arranged on the outer side surface. The operation panel 10 has an inner pan 4 which will be described later in response to signals from the temperature sensor 6 and various sensors.
The control circuit components for controlling the electricity supply to the ceramic heater that constitutes the above and performing the rice cooking and heat retaining operations and the display components such as light emitting diodes are installed.

Similar to the outer pot 1, the outer lid 2 is formed by connecting an inner wall plate 2a and an outer wall plate 2b made of metal such as stainless steel and connecting a heat insulating material 11 between the both wall plates 2a and 2b. A handle 12 is provided on the upper surface. The outer lid 2 having such a structure is rotatably supported by a hinge 13 fixed to an upper end portion of a side surface of the outer pot 1 with a shaft 14, and the outer lid 1 is rotated by the rotation.
Is opened and closed, and the closed state is held by engagement of a latch lever and a latch hook (not shown),
It can be released by releasing the engagement between the latch lever and the latch hook by operating a latch button (not shown). Further, a packing 15 having elasticity such as silicon rubber is provided on the outer peripheral portion on the inner surface side of the outer lid 2 over the entire circumference, and the packing 15 seals the space between the outer lid 1 and the upper end portion. Further, the outer lid 2 has a hanging rod 16 projecting from the center of the inner surface, and a through hole 17 at a position offset from the center.
And a packing 18 having elasticity such as silicon rubber is provided on the inner periphery thereof.

The inner lid 3 is made of a metal such as aluminum, and is detachably fitted and supported on the suspension bar 16 by an elastic packing 19 such as silicon rubber. When the outer lid 2 is closed, the inner lid 3 is closed. The opening of the pan 4 is closed, and the inner lid 3 and the flange portion of the inner pan 4 are brought into a heat conducting state. Further, the inner lid 3 has a steam valve 20 on the upper surface, and the steam valve 20 is inserted into the through hole 17 of the outer lid 2, and the gap formed between the through hole 17 and the steam valve 20 is packed 18 It is sealed by.

The inner pot 4 is composed of a ceramic heater in which a material in which a conductive material is mixed with a ceramic having a large amount of far infrared radiation is molded and fired at a required temperature. In the present embodiment, the specific resistance is made different by changing the compounding ratio of metallic silicon and silicon carbide (the specific resistance increases when the amount of silicon carbide is small), and the specific resistance of the intended resistance is 1400 ° C. I made a ceramic heater. In addition, the inner surface of the inner pot 4 is coated with a fluororesin to insulate the heater and prevent cooked rice from sticking. On the other hand, on the outer surface of the inner pot 4, the power receiving terminals (aluminum plates) 4a and 4b of the ceramic heater are provided on the entire circumference of the lower surface of the collar portion and the center of the lower surface of the bottom portion, and the power feeding terminals (a) attached to the inner wall 1a of the outer pot 1 ( The terminals 21a and 21b having elasticity formed by bending a phosphor bronze plate 21a and 21b receive electric power to generate heat by themselves.

Further, when the outer lid 2 is opened and the inner pot 4 is removed from the outer pot 1, it is dangerous that the power is supplied to the power supply terminals 21a and 21b, and it is dangerous that the outer lid 2 is opened. An outer lid switch 22 whose contacts are turned off is provided on the flange portion of the inner wall 1a in order to cut off the power supply to the power feeding terminals 21a and 21b, and when the inner pot 4 is further removed, the power feeding terminals 21a and 2
An inner pot detection switch 23 whose contact is turned off is provided at the center of the bottom surface of the inner wall 1a in order to cut off the power supply to 1b.

The rice cooker having the above-mentioned structure has a basic electric circuit shown in FIG. 2, and the ceramic heater (inner pot) 4 is energized and controlled by the microcomputer control circuit 24 housed in the operation panel 10 to cook and heat the rice. I do. The control of the rice cooking and the heat retention operation controls the energization of the ceramic heater 4 based on the temperature information detected by the temperature sensor 6 and the temperature information of the entire inner pot 4 detected by measuring the resistance value of the ceramic heater 4. It is done by The resistance value of the ceramic heater 4 is measured by the control circuit 24 breaking the contacts 25a and 25b of the relay 25 at predetermined time intervals, and the measured resistance value is obtained in advance by an experiment and stored in the memory-the inner pot. Based on the temperature data table, the temperature of the entire inner pot 4 is converted into temperature information.

Further, the outer lid 2 is opened to open the outer lid switch 22.
When the power is turned off, an off signal is output to the relay 25, the contacts 25a and 25b are turned off, and the power supply terminals 21a and 2b are turned off.
1b disappears in a live state and becomes an electrically safe state.
When the inner pan 4 is further removed, the inner pan detection switch 23 turns off.
However, since the same operation is performed, double safety measures are taken against the contact failure of the switches 22 and 23. Reference numeral 26 shown in FIG. 2 is a current fuse for ensuring the safety of the rice cooker.

By using the rice cooker having the above-mentioned structure, the inner pot 4 formed by the salamic heater self-heats and becomes a heat source, which is used for the material (rice) in the inner pot 4 from the inner pot 4. A large amount of far-infrared rays are radiated so as to wrap them up, and the far-infrared rays can cook the whole rice fluffy and evenly. Further, the time required for cooking rice can be shortened and the power consumption can be reduced due to the heat efficiency of the inner pot 4 by self-heating and the effect of heating from the inside by far infrared rays.

Furthermore, since a space for installing a heat source is not required, the rice cooker becomes compact, and the heat of the inner pot 4 can be effectively transmitted to the inner lid 3, and the dew-prevention heater provided on the inner lid 3 can be used. In addition to being unnecessary, cost reduction can be achieved, and the heat retention performance is good and deodorizing effect can be expected. Further, when the outer cover 2 is opened, the circuit for supplying power to the ceramic heater 4 is cut off by the outer cover switch 22, and the receiving / supplying terminal (exposed energizing portion) of the ceramic heater 4 is in a power failure state (inactive electricity state). When the inner pot 4 is taken out, the circuit for supplying power to the ceramic heater 4 is cut off by the inner pot detection switch 23 to ensure electrical safety. Besides, it is possible to remove the electricity without the pan.

Furthermore, the temperature of the entire inner pot 4 is detected by measuring the resistance value of the ceramic heater 4, and the heater energization control of the rice cooking operation and the heat retention operation is performed based on the resistance value (temperature).・ Insulation performance is improved.

[0025]

As described above, according to the present invention, it is possible to provide a compact rice cooker in which the space for arranging a heat source is reduced, and it is possible to cook the whole rice evenly and fluffy from the inside. It is possible to reduce the time required for cooking rice and the power consumption accompanying it due to the heat efficiency of self-heating and the heating effect from the inside by far infrared rays. Further, when the lid is opened or the inner pot is taken out, the power supply circuit to the ceramic heater is cut off and the exposed energized portion is in a power failure state, so that an electrically safe rice cooker can be provided.

Furthermore, since the heater energization control for the rice cooking operation and the heat retention operation is performed based on the temperature of the entire inner pot, the rice cooking / heat retention performance is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a rice cooker of the present invention.

FIG. 2 is a basic electric circuit diagram of the rice cooker of the present invention.

[Explanation of symbols]

 1 Outer pan (rice cooker main body) 2 Outer lid (lid) 3 Inner lid 4 Inner pot (ceramic heater) 21a, 21b Power supply terminal (power supply circuit) 22 Outer lid switch (lid switch) 23 Inner pot detection switch 24 Control Circuit (control means)

Claims (4)

[Claims] 1. A rice cooker comprising a rice cooker main body, an inner pan to be housed in the rice cooker main body, and a lid body which covers the rice cooker main body so as to be openable and closable, wherein the inner pan is formed of a ceramic heater. In addition, the rice cooker is provided with a power supply circuit for supplying power to the ceramic heater of the inner pot. 2. The rice cooker according to claim 1, further comprising a lid switch that shuts off the power feeding circuit when the lid is opened. 3. The rice cooker according to claim 1, further comprising an inner pan detection switch that shuts off the power supply circuit when the inner pan is taken out. 4. The rice cooker according to claim 1, further comprising control means for measuring the heater resistance value of the inner pot and controlling the energization of the heater based on the measured heater resistance value. Characteristic rice cooker.