JP2011240014A - Electric rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric rice cooker capable of preventing ingredients and seasonings from becoming deposited in an internal pot and thereby preventing objects to be heated from being overheated or scorching during cooking of rice such as Takikomi Gohan, which is rice seasoned with soy sauce and boiled with meat or seafood and other savory vegetables.SOLUTION: According to the electric rice cooker, before heating units (an induction coil 31, a lateral heater 32, and a lid heater 39) perform a heating operation, a preliminary stir operating unit 51 of a control unit 30 performs a preliminary stir operation thereby to cause a stir blade 40 to rotate in the internal pot 10 prior to the heating operation. This preliminary stirring enables the objects to be heated in the internal pot to be reliably stirred without requiring a user to bear the burden of manually stirring the objects to be heated in the internal pot 10 before the heating operation, thus making it possible to cause rice to absorb seasonings sufficiently, prevent the ingredients and seasonings from becoming deposited on the bottom, reliably prevent the electric rice cooker from turning off earlier than it should or prevent the ingredients and seasonings from scorching, and cook good Takikomi Gohan.

Description

  The present invention relates to an electric rice cooker.

  Conventionally, as an electric rice cooker, by automatically reciprocatingly swinging the rice cooking heater in a direction parallel to the bottom of the pan, the heating state of the pan bottom at the time of rice cooking is made uniform to prevent uneven cooking and scorching. Such a system has been proposed (Patent Document 1 (Japanese Utility Model Publication No. 62-10824)).

  By the way, when cooking cooked rice with an electric rice cooker, stir the heated object in the inner pot by hand immediately before cooking, so that the ingredients and seasoning are prevented from settling in the inner pot Explained. This is because if the ingredients and seasonings are precipitated in the inner pot, it will cause scorching and premature cutting. Premature cutting means that what has settled in the inner pan is overheated and goes to the next operation step. If premature cutting occurs, the heating time is shortened and the core remains in the rice.

  However, if the user stirs by hand, there is a problem that the user is burdened and forgetting to mix easily occurs. In addition, when cooking cooked rice, even if the user stirs the object to be heated in the inner pot by hand, it settles again when time elapses, so the timer reservation operation cannot be performed.

Japanese Utility Model Publication No. 62-10824

  Therefore, an object of the present invention is to provide an electric rice cooker capable of preventing overheating and scorching of an object to be heated by preventing precipitation of ingredients and seasonings in the inner pot in rice cooking such as cooked rice. is there.

In order to solve the above-mentioned problem, an electric rice cooker of the present invention includes an inner pot that accommodates an object to be heated,
A rice cooker body in which the inner pot is stored;
A lid that can be freely opened and closed at the top of the rice cooker body, and can be closed to cover the inner pot,
An agitator arranged rotatably in the inner pot;
A rotation driving device that is arranged outside the inner pot and rotationally drives the agitator;
A heating unit for heating the inner pot housed in the rice cooker body;
A control unit for controlling the heating unit and performing a heating operation,
The control unit
Before performing the heating operation by the heating unit, it has a pre-stirring operation unit that performs a pre-stirring operation for operating the rotation driving device and rotating the stirring body.

  According to the electric rice cooker of the present invention, before the heating operation by the heating unit is performed, the preliminary stirring operation unit of the control unit executes the preliminary stirring operation, thereby rotating the stirring body in the inner pot. And pre-stir. By this preliminary agitation, the object to be heated in the inner pot can be reliably agitated before the heating operation without imposing a burden on the user to stir the object to be heated in the inner pot by hand before the heating operation. Therefore, when cooking cooked rice or the like, the ingredients and seasonings in the inner pot can be prevented, so that the heated object can be prevented from being overheated or burnt, and delicious cooked rice can be made.

Moreover, in the electric rice cooker of one Embodiment, the said control part is
A timer reservation unit capable of making a timer reservation for execution of the preliminary stirring operation by the preliminary stirring operation unit;

  According to the electric rice cooker of this embodiment, the timer reservation unit can make a timer reservation for the execution of the preliminary stirring operation, and can cook rice such as cooked rice by timer reservation without causing premature breakage or burning.

  According to the electric rice cooker of the present invention, the object to be heated in the inner pot can be reliably stirred before heating operation without imposing a burden on the user, so when cooking cooked rice or the like, it can be quickly cut or burnt. It can be surely prevented.

FIG. 1 is a perspective view of an electric rice cooker according to an embodiment of the present invention. FIG. 2 is a perspective view of the electric rice cooker with the lid opened. FIG. 3 is a longitudinal sectional view of the electric rice cooker as seen from line III-III in FIG. FIG. 4 is a longitudinal sectional view of the electric rice cooker as seen from line IV-IV in FIG. FIG. 5 is a control block diagram of the electric rice cooker. FIG. 6 is a flowchart for explaining the operation of the electric rice cooker. FIG. 7 is an operation timing chart in the preliminary stirring operation mode of the electric rice cooker.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

  FIG. 1: has shown the perspective view which looked at the electric rice cooker of one Embodiment of this invention from diagonally upward.

  As shown in FIG. 1, the electric rice cooker of this embodiment includes a rice cooker body 1 and a lid 2 attached to the rice cooker body 1 so as to be freely opened and closed. The rice cooker main body 1 includes a display operation unit 3 provided on the front side, a hook button 4 provided on the front side and the upper side, a main body handle 5 rotatably attached to the rear side, and a rear side and a lower side. And a power cord 6 connected to the side. A steam port 2 a is provided on the rear surface side of the lid 2. The display operation unit 3 includes a liquid crystal display and a plurality of operation buttons, and can display and operate a cooking menu, cooking status, and the like. The lid 2 is closed in a state where it is detachably locked by a latch mechanism (not shown) provided in the rice cooker body 1, and when the hook button 4 is pressed, the latch mechanism is released, and the spring The lid 2 is opened by an urging force of 26 (shown in FIG. 3).

  Moreover, FIG. 2 has shown the perspective view of the state which opened the cover body 2 of the said electric rice cooker, and attaches | subjects the same reference number to the component same as FIG.

  As shown in FIG. 2, this electric rice cooker supports the lid 2 so as to be rotatable in the vertical direction via a hinge shaft 20 (shown in FIG. 3) provided on the upper and rear side of the rice cooker body 1. is doing. The lid 2 has an outer lid 21 and an inner lid 22. Moreover, the inner pot 10 which accommodates to-be-heated material in the rice cooker main body 1 is accommodated.

  An annular flange portion 10 a is provided on the edge of the upper opening of the inner pot 10. As shown in FIG. 4, heat-resistant resin inner pot handles 11, 11 are attached to positions facing the radial direction of the flange portion 10 a of the inner pot 10. Concave portions 12a (only the right side is shown in FIG. 2) are provided at two locations on the left and right sides of the upper surface of the rice cooker body 1. As shown in FIG. The inner pot handles 11, 11 of the inner pot 10 are fitted into the two recesses 12a, respectively. Thereby, the inner pot 10 accommodated in the rice cooker body 1 is positioned with respect to the rice cooker body 1.

  FIG. 3 shows a longitudinal sectional view of the electric rice cooker as viewed from line III-III in FIG. 1. As shown in FIG. 3, the rice cooker main body 1 includes an outer case 12 and an outer case 12. And an inner case 13 that houses the inner pot 10. The inner case 13 is formed of a material having heat resistance and electrical insulation.

  A power supply unit 14 including a power supply circuit and an inverter circuit is disposed on the rear surface side (right side in FIG. 3) between the outer case 12 and the inner case 13, and the power supply unit 14 is provided below the power supply unit 14. A cooling fan 15 is disposed to cool the air. Further, a cord reel 7 for winding the power cord 6 is disposed below the cooling fan 15 and at the bottom of the outer case 12.

  Moreover, the cylindrical convex part 10b which protrudes inside is provided in the bottom part of the inner pot 10. A disc-shaped stirring blade 40 is rotatably fitted to the convex portion 10 b of the inner pot 10. The stirring blade 40 includes an annular yoke 41 and a plurality of magnets 42 arranged at equal intervals in the circumferential direction inside the yoke 41. An opening 13 a is provided in the region of the inner case 13 that faces the convex portion 10 b of the inner pot 10. And the rotor 16 with which the several magnet 18 was arrange | positioned at the circumferential direction and equal intervals is arrange | positioned under the convex part 10b of the inner pot 10, and the inner peripheral side of the convex part 10b, and the axial part 16a of this rotor 16 is arranged. The stirring motor 17 to which the rotating shaft 17a is connected is disposed below the bottom of the inner pot 10. The agitation motor 17 and the rotor 16 are an example of a rotation drive device. Also, 90 in FIG. 3 is a cover that covers the rotor 16.

  The rotor 16 and the agitating blade 40 are connected by a radial magnetic coupling by the respective magnets 18 and 42, and the rotor 16 driven by the agitating motor 17 is rotated to rotate the agitating blade via the magnetic coupling. 40 rotates.

  Further, on the front side of the space between the outer case 12 and the inner case 13 (left side in FIG. 3), the display / operation unit 3 (shown in FIGS. 1 and 2), the inverter circuit of the power supply unit 14 and the cooling fan 15 are provided. And the control part 30 which controls the stirring motor 17 grade | etc., Is arrange | positioned.

  Moreover, the induction coil 31 for induction-heating the inner pot 10 is arrange | positioned under the inner case 13 in the rice cooker main body 1 and the outer side. The induction coil 31 is bonded to the outer surface of the inner case 13 with a heat-resistant resin or the like. Further, a ferrite member 38 for preventing leakage magnetic flux of the induction coil 31 is disposed below the induction coil 31. Furthermore, the horizontal heater 32 is arrange | positioned along the circumferential direction so that the upper side surface of the inner case 13 in the rice cooker main body 1 may be enclosed. Further, a bottom temperature sensor 33 penetrating the inner case 13 is disposed below the inner case 13. The bottom temperature sensor 33 detects the temperature of the inner pot 10 by contacting the tip of the bottom pot near the bottom of the inner pot 10 housed in the inner case 13. A lid heater 39 (shown in FIG. 4) and a lid temperature sensor 34 (shown in FIG. 5) are arranged in the lid 2.

  The induction coil 31, the lateral heater 32, and the lid heater 39 constitute a heating unit that heats the entire inner pot 10.

  The inner pot 10 is formed of a high heat conductive member such as aluminum, for example, and a magnetic material such as stainless steel for improving the heating efficiency is attached to the outer surface of the inner pot 10, while a fluororesin for preventing adhesion of an object to be heated is attached to the inner surface. It is coated.

  On the other hand, the lid body 2 includes an outer lid 21 in which the lid body 2 is rotatably supported via a hinge shaft 20 (shown in FIG. 3) provided on the upper and rear side of the rice cooker body 1. An inner lid 22 is detachably attached to the side of the outer lid 21 facing the inner pot 10. An annular heat-resistant rubber packing 23 is detachably attached to the outer periphery of the inner lid 22. When the lid 2 is closed, the packing 23 is in close contact with the upper surface of the flange portion 10 a of the inner pot 10 to seal between the inner pot 10 and the inner lid 22. In FIG. 3, reference numeral 24 denotes a steam hole provided in the inner lid 22.

  FIG. 4 shows a vertical cross-sectional view of the electric rice cooker as viewed from the line IV-IV in FIG. 1. As shown in FIG. 4, the electric rice cooker is provided at two left and right positions on the upper surface of the outer case 12 of the rice cooker body 1. When the inner pot handles 11, 11 of the inner pot 10 are fitted into the recesses 12 a, 12 a, the inner pot 10 is positioned with respect to the rice cooker body 1.

  A magnet 50 is embedded in the inner pot handle 11. Further, a reed switch 25 as a magnetic sensor that is turned on by the magnetism of the magnet 50 when the lid body 2 is closed is attached to a portion of the outer lid 21 that is positioned on the magnet 50. A magnet 50 is embedded in both of the inner pot handles 11 and 11. Moreover, you may use a Hall element as said magnetic sensor.

  FIG. 5 shows a control block diagram of the electric rice cooker. The control unit 30 includes a microcomputer and an input / output circuit, and the display operation unit 3 is based on an operation signal from the display operation unit 3, a signal from the reed switch 25, the bottom temperature sensor 33, and the lid temperature sensor 34. , Agitating motor 17, cooling fan 15, induction coil inverter circuit 35, side heater circuit 36 and lid heater circuit 37 are controlled. The induction coil inverter circuit 35 causes the induction coil 31 to generate an alternating magnetic field. The induction coil inverter circuit 35, the lateral heater circuit 36, and the lid heater circuit 37 are included in the power supply unit 14 shown in FIG.

  The control unit 30 includes a preliminary stirring operation unit 51. The preliminary stirring operation unit 51 controls the induction coil inverter circuit 35, the lateral heater circuit 36, and the lid heater circuit 37 to perform stirring before the heating operation by the induction coil 31, the lateral heater 32, and the lid heater 39 is performed. The motor 17 is driven to rotate the stirring blade 40. Moreover, the control part 30 has the timer reservation part 52 which can carry out timer reservation of the time which performs the said preliminary stirring operation.

  The preliminary stirring operation is executed by operating the display operation unit 3. In addition, by operating the display operation unit 3, a timer can be reserved for the time to execute the preliminary stirring operation.

  Next, the operation in the case of cooking cooked rice with timer reservation by the electric rice cooker having the above configuration will be described with reference to the flowchart of FIG. 6 and the timing chart of FIG.

  First, after the user stores the inner pot 10 containing appropriate amounts of rice, water, cooked rice ingredients and seasonings in the rice cooker body 1, the display operation unit 3 is operated to make a spare by the preliminary stirring operation unit 51. A timer reservation is made in the timer reservation unit 52 for the stirring operation. Thereby, the time which performs the said preliminary stirring operation is set (step S1).

  Next, the process proceeds to step S2, and the control unit 30 determines whether or not the reed switch 25 is on. If it is determined that the reed switch 25 is not on, the control unit 30 displays an error on the display operation unit 3; The user is urged to securely close the lid 2 in a state where the inner pot 10 is stored in the rice cooker body 1 (step S3). And while control part 30 judges with reed switch 25 not being turned on, it does not progress to the next step.

[Preliminary stirring operation]
Next, when the control unit 30 determines that the reed switch 25 is turned on and the time measured by the timer reservation unit 52 reaches the set time, the preliminary stirring operation is started. 17 is intermittently driven for a predetermined time to rotate the stirring blade 40 intermittently (step S4). In this preliminary stirring operation, the heating operation by the induction coil 31, the lateral heater 32, and the lid heater 39 is not performed. Instead of intermittently driving the agitation motor 17, the agitation blade 40 may be continuously rotated by continuously driving it for a predetermined time. By this preliminary stirring, the seasoning can be sufficiently absorbed by the rice and the ingredients and seasonings can be prevented from precipitating at the bottom.

  Next, it progresses to step S5 and initial temperature detection is performed. In this initial temperature detection, the control unit 30 determines whether or not the temperature in the inner pot 10 detected by the bottom temperature sensor 33 exceeds 135 ° C, and if it is determined that the temperature exceeds 135 ° C, It progresses to step S6, the error display to the effect that the high temperature abnormality of the inner pot 10 generate | occur | produced is performed by the display operation part 3, and a driving | operation is stopped. The user may be alerted by outputting an error sound together with the error display.

[Preheating / stirring operation]
On the other hand, when it is determined by the initial temperature detection that the temperature in the inner pot 10 does not exceed 135 ° C., the process proceeds to step S7, and a preheating / stirring operation is performed.

  In this preheating / stirring operation, the stirring blade 40 is rotationally driven by the stirring motor 17 and a small amount of power is supplied from the induction coil inverter circuit 35 to the induction coil 31 while stirring the inside of the inner pot 10. Thus, the inner pot 10 is induction-heated, the electric power of the induction coil 31 is controlled so as to keep the temperature in the inner pot 10 detected by the bottom temperature sensor 33 at 60 ° C., and the preheating operation is performed for a predetermined time. At this time, by stirring the inside of the inner pot 10 with the stirring blade 40, the heated object (rice and water, etc.) in the inner pot 10 is made to absorb water while maintaining the uniform target temperature (60 ° C.). It produces glucose, an umami component.

  In this preheating / stirring operation, the temperature at which the amylolytic enzyme works most effectively is set to 60 ° C., and the temperature in the inner pot 10 is kept at 60 ° C. for 15 minutes to 20 minutes. In this embodiment, the target temperature of the preheating / stirring operation is set to 60 ° C. However, the present invention is not limited to this, and the target temperature may be set as appropriate according to various conditions. In this preheating / stirring operation, only preheating may be performed without rotating the stirring blade 40.

[Start-up operation]
Next, the process proceeds to step S8, the operation of the agitation motor 17 is stopped and the agitation blade 40 is stopped, and then large power is supplied from the induction coil inverter circuit 35 to the induction coil 31. In addition, the horizontal heater circuit 36 and the lid heater circuit 37 are controlled to heat the inner pot 10 from the side and the upper side by the horizontal heater 32 and the lid heater 39, and the temperature in the inner pot 10 is set to 100. Start-up operation starting at ℃. Here, the temperature in the inner pot 10 is detected by the bottom temperature sensor 33 and the lid temperature sensor 34.

[Cooking operation]
Next, it progresses to step S9 and adjusts the heating amount by the induction coil 31, the horizontal heater 32, and the lid | cover heater 39 until the temperature in the inner pot 10 reaches 120 degreeC after the temperature in the inner pot 10 reaches 100 degreeC. Then, the cooking operation is performed while maintaining boiling. Here, when the water in the inner pot 10 runs out and stops boiling, the temperature in the inner pot 10 begins to rise from 100 ° C.

  By the above cooking operation, heat and water are added to the rice to cause a chemical reaction called gelatinization in which β starch contained in the rice is changed to α starch, and delicious cooked rice can be obtained.

[Steaming operation]
Then, when the temperature in the inner pot 10 reaches 120 ° C., the process proceeds to step S 10, the heating amount by the induction coil 31, the lateral heater 32 and the lid heater 39 is adjusted and the steaming operation is performed for a predetermined time, and then the heating is performed. The cooking (cooking rice) is finished and the operation mode is changed to the heat insulation operation mode (step S9).

  As described above, in this electric rice cooker, when the cooked rice is cooked, the preliminary stirring operation unit 51 of the control unit 30 performs preliminary stirring before heating by the induction coil 31, the lateral heater 32, and the lid heater 39. Do the driving. In this preliminary stirring operation, the stirring blade 40 is rotated in the inner pot 10 by the stirring motor 17 without heating. Thereby, it is possible to sufficiently absorb the seasoning into the rice and prevent the ingredients and the seasoning from being settled to the bottom. Therefore, when cooking cooked rice, the heating operation is performed without causing the user to stir the object to be heated (rice, water, ingredients, seasoning) in the inner pot 10 by hand before the heating operation. Before heating, the heated object in the inner pot 10 can be reliably stirred. Therefore, stirring of the object to be heated is surely performed before the heating operation, and it is possible to reliably prevent premature cuts and scorching and cook delicious cooked rice. In addition, the timer reservation unit 52 can make a timer reservation for the execution of the preliminary stirring operation, so that cooking such as cooked rice by the timer reservation can be performed without premature cutting or burning.

  In addition, in the said embodiment, although the operation | movement in the case of cooking cooked rice with a timer reservation was demonstrated, when a timer reservation is not performed and the control part 30 determines with the reed switch 25 being ON, a preliminary | backup stirring operation part Of course, it is possible to select an operation mode in which the preliminary stirring operation by 51 is started. The preliminary stirring operation is useful because it can prevent some rice bran precipitation that occurs when cooking unwashed rice. Further, in the electric rice cooker of the above embodiment, when normal rice other than cooked rice is performed, the preheating / stirring operation, the start-up operation, the cooking operation, and the steaming are performed without performing the preliminary stirring operation. Of course, the normal operation mode in which the operation is performed can also be selected. In the above embodiment, the timer reservation unit 52 is provided, but the timer reservation unit 52 is not necessarily required. Moreover, in the said embodiment, when the cooked rice mode and the no-wash rice cooking mode can be selected with the display operation part 3, and the cooked rice mode and the no-wash rice cooking mode are selected, the rice cooking operation including the above-mentioned preliminary stirring operation is performed. May be performed.

  In the above embodiment, the rotation is transmitted from the stirring motor 17 to the stirring blade 40 by magnetic coupling using the magnets 18 and 42, but the stirring blade 40 may be directly connected to the rotating shaft 17 a of the stirring motor 17. In this case, a seal device for preventing water leakage is provided at a location where the rotary shaft 17a penetrates the inner pot 10. Further, instead of the agitation motor 17 and the rotor 16, for example, a stator yoke of a synchronous motor, a plurality of coils wound around the stator yoke, and a rotating magnetic field for generating a rotating magnetic field in the plurality of coils. An AC power source may be used. By generating a rotating magnetic field by the stator yoke and the AC power source, the magnetically coupled stirring blade 40 can be driven to rotate. In short, any device that can generate a rotating magnetic field may be housed in a recess on the outer surface of the bottom of the inner pot 10. In the above embodiment, a heater similar to the horizontal heater 32 may be used instead of the induction coil 31. When this heater is used, it is not necessary to attach a magnetic body to the outer surface of the high heat conductive member of the inner pot 10.

  While specific embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Electric rice cooker main body 2 ... Lid 2a ... Steam port 3 ... Display operation part 4 ... Hook button 5 ... Main body handle 6 ... Power cord 7 ... Cord reel 10 ... Inner pan 10a ... Flange part 10b ... Convex part 11 ... Inside Pan handle 12 ... Outer case 12a ... Concave 13 ... Inner case 14 ... Power supply 15 ... Cooling fan 16 ... Rotor 17 ... Stirring motor 18 ... Magnet 20 ... Hinge shaft 21 ... Outer lid 22 ... Inner lid 23 ... Packing 24 ... Steam hole DESCRIPTION OF SYMBOLS 25 ... Reed switch 26 ... Spring 30 ... Control part 31 ... Induction coil 32 ... Side heater 33 ... Bottom temperature sensor 34 ... Cover temperature sensor 35 ... Inverter coil inverter circuit 36 ... Circuit for side heater 37 ... Circuit for cover heater 38 ... Ferrite member 39 ... lid heater 40 ... stirring blade 41 ... yoke 42 ... magnet 50 ... magnet 51 ... pre-stirring operation section 52 ... timer reservation section

Claims (2)

An inner pot for storing the object to be heated;
A rice cooker body in which the inner pot is stored;
A lid that can be freely opened and closed at the top of the rice cooker body, and can be closed to cover the inner pot,
An agitator arranged rotatably in the inner pot;
A rotation driving device that is arranged outside the inner pot and rotationally drives the agitator;
A heating unit for heating the inner pot housed in the rice cooker body;
A control unit for controlling the heating unit and performing a heating operation,
The control unit
An electric rice cooker having a pre-stirring operation unit for performing a pre-stirring operation for operating the rotation driving device and rotating the stirring body before performing the heating operation by the heating unit. In the electric rice cooker according to claim 1,
The control unit
An electric rice cooker comprising a timer reservation unit capable of making a timer reservation for execution of the preliminary stirring operation by the preliminary stirring operation unit.

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