JP6369139B2 - Electric rice cooker - Google Patents

Description

  The invention of this application includes an outer hook made of ceramic material on the outer periphery of the inner pot made of ceramic material, the inner hook is located on the outer peripheral face of the inner hook, and the outer hook is the inner peripheral face of the outer hook. It is related with the structure of the electric induction cooker of the electromagnetic induction heating type | formula which is located in each, and the induction heating part was provided, More specifically, it is related with the water absorption heating control in the water absorption process in the electric rice cooker which employ | adopted the structure is there.

  Recently, an electromagnetic induction heating type rice cooker with an inner pot made of a ceramic material such as a clay pot has gained popularity as an inner pot that can cook delicious rice with good cooked rice. .

  In such an electric rice cooker equipped with a ceramic inner pot, the inner pot itself does not generate heat due to electromagnetic induction. For example, an induction heating portion such as a silver paste is provided on the bottom portion of the inner pot and the curved portion on the outer periphery of the bottom portion. The induction heating part is induction-heated by electromagnetic induction means such as a work coil to heat the inner pot and cook rice.

  On the other hand, on the rice cooker body side, an inner pot accommodating space for accommodating such an inner pot is formed, and a bottomed cylindrical protective frame made of heat-resistant synthetic resin is formed in the inner pot accommodating space. A storage groove for the ceramic inner pot is formed through the bottomed cylindrical protective frame. And on the outer periphery of the bottom of the protective frame, a work coil for inductively generating heat from the induction heat generating part corresponding to the bottom of the inner pot made of ceramic and the induction heat generating part on the outer periphery of the bottom, etc. The electromagnetic induction means is provided.

  Therefore, when the electromagnetic induction means is driven, the induction heating part of the ceramic inner pot is electromagnetically induced through the protective frame, and the eddy current flows through the induction heating part by the electromagnetic induction to generate heat. A ceramic inner pot is heated from the bottom side to the side, and an effective temperature rise using the heat storage power (the amount of heat storage) unique to the ceramic material is achieved. It can be cooked (see the configuration of Patent Document 1).

JP 2007-244648 A JP 2013-244107 A

  However, in the case of an electric rice cooker with the same configuration, the inner pot is a ceramic material, and once heated to a high temperature state, the heat storage power (heating power based on the heat storage amount) is large, but the specific heat is small, so the high temperature state. It takes a long time to become and since the thermal conductivity is small, even if a part is heated, the whole has a characteristic that heat is hardly transmitted.

  In addition, since the inner hook is only provided with the induction heat generating portion on the outer peripheral surface of the bottom portion and the outer peripheral surface of the bent portion from the bottom portion to the side portion, the bottom portion and the bent portion become considerably hot if a certain time is taken. The heat is not easily transmitted to the side portions, and the temperature increase rate of the side portions is low.

  Therefore, regardless of whether it reaches the cooking process from the water absorption process to the temperature rising process, even in the water absorption process, especially in the water absorption process, even if the heating power is increased, the temperature of the bent portion at the bottom and the bottom outer periphery. However, the temperature on the side part does not rise easily.

  Thus, in the situation where the temperature on the bottom side is high and the temperature on the side side is low, a phenomenon in which the contents of the rice skin on the lower layer side melt and the contents flow out is observed. And when the quantity of the content which flowed out increases, the same content will adhere to the bottom face of an inner pot, and will cause water absorption nonuniformity. At the same time, the rice stops moving, causing a burn.

  On the other hand, since the temperature of the side part of the inner pot is low, the heating amount of the upper rice and water is not sufficient, and the effective water absorption effect cannot always be improved. Therefore, this also causes uneven water absorption.

  In addition, in the case of the electric rice cooker having the above configuration, the induction heating portions of the inner pot bottom portion and the bent portion are on the outer peripheral surface side of the inner pot bottom portion and the bent portion, respectively, and the heat on the outer peripheral surface passes through to the inner peripheral surface side. Although the rice is heated, the thermal resistance of the inner pot wall made of ceramic material is large not only in the wall surface direction as described above but also in the thickness direction, and easily on the inner peripheral surface side. It does not flow through. Therefore, a considerable amount of heat at the bottom of the inner hook and the outer peripheral surface side of the bent portion is discharged to the surroundings, and not only is the amount of heat (thermal power / electric power) wasted, but the inner pot is also stored. It also affects the heat resistance of the protective frame on the outer periphery side of the groove, and requires a high heat resistant structure.

  Therefore, in order to solve such a problem, a ceramic outer pot having a earthen function covering from the bottom of the inner hook to the vicinity of the bent portion is provided inside the bottom of the protective frame, The heat of the bottom part and the curved part outer peripheral surface side that becomes high temperature around the induction heating part is securely wrapped by the ceramic outer pot, and the bottom part of the inner pot and the bent part outer peripheral surface are maintained at a sufficiently high temperature state, The same high-temperature heat is allowed to flow from the outer peripheral surface side of the inner pot to the inner peripheral surface side, and is transferred as efficiently as possible from the bottom and the bent portion side to the side portion (heating by heat conduction in the wall portion and Heating by the high temperature air convection rising along the wall surface), improving the heating unevenness by heating the entire inner surface and the inner peripheral surface from the bottom to the vicinity of the side as efficiently as possible. Also suggest Are (see the configuration of Patent Document 2, supra).

  According to such a configuration, the radiant heat from the outer peripheral surface of the inner pot bottom portion having the induction heat generating part is reflected and stored in the outer pot having a highly heat-insulating earth structure to efficiently store the temperature of the outer peripheral surface of the inner pot. It can be kept as high as possible. As a result, the flow rate of heat to the inner peripheral surface side of the inner hook is increased, and the high temperature heat from the outer peripheral surface of the inner pot bottom accumulated between the outer hook and the inner pot side is passed through the inner pot wall. The hot air in the heat storage space between the outer hook and the outer hook is raised along the outer peripheral surface of the inner hook by convection, thereby raising the temperature of the inner hook side.

  In this way, heat transfer is low and difficult to heat, but once heated to a high temperature, the heat storage power of the ceramic inner pot with large heat storage power is effectively utilized, and the inner pot containing rice and water is , A relatively large amount of heat is stored from the bottom to the side, and it becomes possible to realize a continuous boiling state with a large heating power for a long time, which promotes alpha conversion of the cooked rice In addition, it is possible to cook a solid and delicious rice while fluffing from the core.

  Further, since the outer hook functions as a heat shield plate to the protective frame and the work coil side, the heat resistance standards on the protective frame and the work coil side are also gradual.

  However, in the case of the configuration of this conventional example, the induction heating part for heating the inner pot is arranged at two places, the bottom part and the curved part of the inner pot in order to make the heating area as wide as possible, and the electromagnetic induction means corresponding thereto. Although it is disposed at two places, the bottom portion of the protective frame and the bent portion, it is not provided at the side portion of the inner hook. Therefore, as described above, the outer hook performs the function of the inner hook and prevents the heat generated from the outer periphery of the inner hook induction heat generating portion and the bottom of the inner hook provided with the induction heat generating portion from escaping to the outside. Although the outer pot can be made to act as effectively as possible on the inner pot side, the outer pot is only provided to cover the bottom of the inner pot and the outer periphery of the bent part, and the outer pot itself generates heat. It is not a thing, it just covers the bottom of the inner pot and the outer periphery of the bent part so that the heat from the induction heating part does not escape, and even if the heat storage power of the inner pot is large, the heat transfer is poor, Since the heat from the induction heating part is not easily transmitted to the whole, whether the heating amount of the inner hook side part is sufficient is not enough.

  In particular, in the case of this conventional configuration, the outer hook covers the bottom of the inner hook and the main purpose is to hold the heat of the inner hook bottom part, so the heat quantity relationship between the bottom side and the side part is Rather, the amount of heat on the bottom side is larger, and it cannot be a means for solving uneven water absorption in the water absorption process as described above. Accordingly, the problem of excessive heating at the bottom side in the water absorption step and the problem of unforeseen heating amount for the upper layer of rice have not been solved.

  When rice is cooked in an earthen bowl, the temperature in the kettle reaches about 120 ° C even though there is no pressure in the kettle. This is because in the case of rice bran, the heating during cooking is good, and it is also heated effectively from the side of the kettle, and the rice cooked with rice cake is particularly delicious when the side and top of the rice are above By being heated evenly at such a high temperature. This is exactly the same in the case of the water absorption process.

  For this reason, in the case of the conventional electric rice cooker with an outer pot, auxiliary heating means consisting of a cord heater is separately provided in the protective frame portion corresponding to the side portion of the inner pot, and the auxiliary heating means To compensate for the lack of heating. However, if the inner heat of the inner pot is increased, the side wall thickness is inevitably increased. Indirect heating with a cord heater is not sufficient, and the amount of heat is not sufficient, such as an earthen jar. I can't get firepower.

  Of course, an induction heating part similar to that of the bottom part and the bent part is provided on the outer periphery of the side part of the inner hook, while an electromagnetic induction means such as a work coil is provided instead of a code heater in the protective frame part to induce induction heat generation. It is also possible to heat the part by induction. In this way, the amount of heating at the side of the inner pot is sufficient, but the temperature rise is local, and the side of the inner pot is near the upper surface of water and rice during absorption, It is a part corresponding to the vicinity of the upper part of the rice at the time of cooking, the thermal power is too strong as it is, and there arises a problem that the same part is burnt.

  Therefore, even if an induction heating unit for heating the side portion of the inner pot is provided to realize the cooking of rice close to the rice cake, it is required that the heat generated by the induction heating unit does not cause burning of the rice. In addition, it must be considered that the amount of heat generated at the bottom induction heating portion of the inner hook is more effectively utilized than that of Patent Document 2.

The invention of this application was made on the premise of such a technical problem, and is a ceramic outer pot that covers from the bottom side to the side of a ceramic inner pot having an induction heating portion on the bottom side outer peripheral surface. one to achieve effective use of the inner hook heat is provided, the induction heating portion on the side in the circumferential surface of the outer hook covering the side portion of the inner hook provided, the side of the inner hook indirectly by the outer hook It is an object of the present invention to provide an electric rice cooker that can effectively eliminate heating shortage and water absorption unevenness at the side portion of the inner pot in the water absorption step by enabling heating.

In order to solve the above-described problems, the invention of this application includes the following problem solving means.
(1) The problem-solving means of the invention of claim 1 According to the problem-solving means of the present invention, a ceramic inner pot having an induction heat generating portion on the outer peripheral surface of the bottom, and an inner pot in which the inner pot is accommodated via a protective frame and rice cooker body defining a receiving groove provided in the inner pot accommodating groove of the cooker body, a ceramic outer hook covering up the side from the bottom of the inner pot, the bottom outer periphery of the outer holder An electromagnetic induction means for inductively generating heat from the induction heat generating portion on the outer peripheral surface of the bottom portion of the inner hook through the outer pot; an induction heat generating portion provided on the inner peripheral surface of the side portion of the outer pot; and the outer pot An electromagnetic induction means for inductively generating heat from the induction heat generating portion on the inner peripheral surface of the side portion of the outer pot, and a lid provided on the upper portion of the inner pot storage groove of the rice cooker body. In the water absorption process, the electromagnetic induction means provided on the outer peripheral side of the bottom of the outer pot is driven. Moving to together to induction heating the induction heating of the bottom outer peripheral surface of the inner pot, the outer holder and drives the electromagnetic induction means provided on the side outer periphery of the outer induction heating portion of the side inner peripheral surface of the shuttle By inductively generating heat, the side portion of the inner hook is effectively heated without increasing the heating amount of the bottom portion of the inner pot.

  According to such a configuration, first, the bottom portion of the ceramic inner pot is heated by the induction heat generation of the induction heat generating portion on the outer peripheral surface of the bottom portion, and becomes high temperature, and the heat at the same temperature eventually goes from the bottom side to the side portion side. It is gradually conducted through the wall, and eventually the temperature on the side increases to a predetermined temperature.

In this configuration, in addition to, the protection frame to the inner hook accommodating grooves of the rice cooker main body which is formed through the protective frame and another ceramic outer hook is provided, the outer pot is conventional Unlike the above, it is configured so as to cover from the bottom of the inner pot where the temperature gradually rises as it is heated by the heat generated by the induction heat generating part on the outer peripheral surface of the bottom to the side that has been difficult to be heated conventionally .

  Therefore, the heat generated in the induction heat generating part at the bottom outer peripheral surface side of the inner pot and the radiant heat radiated outward from the outer peripheral surface of the inner pot whose temperature has been increased by the heat generated by the ceramic outer pot with extremely low thermal conductivity. Insulated and stored, heat is stored in the heat storage space between the inner and outer pots so as to wrap the outer periphery of the inner pot from the bottom of the inner pot, and the outer peripheral surface of the inner pot is heated and heated in the same heat storage state.

In addition, high-temperature air between the inner pot and the outer pot heated and heated in the same heat storage state rises from the outer peripheral surface side of the inner pot to the outer peripheral surface side by the convection, and The side outer peripheral surface of the inner hook is effectively heated and heated.

  As a result, the temperature of the inner pot rises relatively quickly from the bottom side to the entire side, and effectively stores the amount of heat corresponding to the temperature rise. Therefore, the amount of heat generated in the induction heating portion at the bottom of the inner hook can be effectively applied to the entire inner hook without wasting it, and the thermal efficiency is improved. As a result, it is possible to reduce the drive output of the electromagnetic induction means for inductively generating heat at the induction heating portion at the bottom of the inner hook.

In addition, in the case of the configuration of the problem solving means of the present invention, in that case, the induction heat generating portion is further provided on the inner peripheral surface of the side portion of the outer hook configured to wrap the outer periphery of the side portion from the bottom portion of the inner hook. In addition, electromagnetic induction means for inductively heating the induction heat generating part is provided on the outer peripheral side of the outer hook corresponding to the induction heat generating part, and heat generated by the induction heat generating part on the inner peripheral surface of the outer hook side by the electromagnetic induction means. The side part of the outer hook itself is induction-heated from the inner peripheral surface side.

Therefore, the ceramic outer hook not only simply covers the outer periphery of the inner hook so as not to release the heat from the inner hook side, but is itself heated from the inner peripheral surface side by the induction heating portion. Efficiently hot, the outer pot side in the same high temperature state actively heats the outer periphery of the inner pot side, and the inner pot side that was previously insufficient in heating is effectively heated. The temperature rises. In addition, the heating of the side portion of the inner pot by the outer pot causes the radiant heat generated by the heat generated by the induction heating section on the inner peripheral surface of the outer pot and the inner circumference of the outer pot through the heat storage space between the inner pot and the outer pot. Since the radiant heat from the outer side of the outer pot, which has become hot due to the heat generated by the induction heating section of the surface, becomes indirect heating due to the effective action, a conventional outer pot having an induction heating section on the inner peripheral surface is provided. In addition, the entire side of the inner hook is uniformly heated while performing a much higher heating effect than indirect heating of the inner hook side by only the side heater outside the protective frame. It is not necessary to cause scorching due to local heating as in the case where an induction heating part is provided directly on the outer peripheral surface of the part.

In the case of the configuration of the problem solving means of the present invention, while assuming these configurations, at least in the water absorption process, the electromagnetic induction means provided on the outer peripheral side of the bottom portion of the outer pot is driven to drive the outer periphery of the bottom portion of the inner pot. Inductive heat generation of the induction heat generating portion of the surface and driving of the electromagnetic induction means provided on the outer peripheral side of the outer hook to cause the induction heat generating portion provided on the inner peripheral surface of the outer hook to induce heat generation The side portion of the inner hook is effectively heated without increasing the heating amount of the inner hook bottom.

  Therefore, the output of the electromagnetic induction means provided on the outer peripheral side of the bottom portion of the outer hook and the output of the electromagnetic induction means provided on the outer peripheral side of the side portion of the outer hook are controlled to a predetermined appropriate relationship, If the heat generation amount of the induction heat generating portion of the surface and the heat generation amount of the induction heat generating portion provided on the inner peripheral surface of the side portion of the outer pot are appropriately adjusted, the heating amount of the inner pot bottom portion is increased in the water absorption process. Without increasing the amount of heating at the side portion of the inner pot, it is possible to increase the heating temperature, and the entire area from the bottom side to the upper side of the rice in the inner pot can be absorbed uniformly at a uniform temperature. It becomes like this.

  As a result, due to local heating only on the bottom side as in the past, the rice skin melts and the contents flow out, sticking to the bottom of the inner pot, the problem of uneven water absorption, and the rice does not move, Problems such as burning can be reliably solved. Moreover, as a result of eliminating the water absorption unevenness, the water absorption efficiency is improved and the water absorption rate is reliably increased.

Therefore, the finally cooked rice is also fluffy from the core, and it becomes a solid and delicious rice.
(2) The problem solving means of the invention of claim 2 In the problem solving means of the invention, in the structure of the problem solving means of the invention of claim 1 above, the output of the electromagnetic induction means provided on the outer peripheral side of the bottom of the outer hook. By increasing the output of the electromagnetic induction means provided on the outer peripheral side of the side portion of the outer hook, the induction heat generating portion provided on the inner peripheral surface of the side portion of the outer hook is larger than the heat generation amount of the induction heat generating portion on the outer peripheral surface of the bottom portion of the inner hook. The amount of heat generated is increased.

  In this way, the output of the electromagnetic induction means provided on the outer peripheral side of the outer hook is made larger than the output of the electromagnetic induction means provided on the outer peripheral side of the bottom of the outer hook, thereby If the heating value of the induction heating part provided on the inner peripheral surface of the outer side of the outer pot is larger than the heating value of the inner pot, the heating of the side part of the inner pot can be performed without increasing the heating amount of the inner pot bottom in the water absorption process. It becomes possible to increase the heating temperature by increasing the amount, and it becomes possible to uniformly absorb water from the bottom side to the upper side of the rice in the inner pot at a uniform temperature.

  As a result, due to local heating only on the bottom side as in the past, the rice skin melts and the contents flow out, sticking to the bottom of the inner pot, the problem of uneven water absorption, and the rice does not move, Problems such as burning can be reliably solved. Moreover, as a result of eliminating the water absorption unevenness, the water absorption efficiency is improved and the water absorption rate is reliably increased.

Therefore, even the cooked rice is fluffy from the core and becomes a solid and delicious rice.
(3) Problem solving means of the invention of claim 3 In the problem solving means of the invention, in the structure of the problem solving means of the invention of claim 1 or 2, the electromagnetic induction means provided on the outer peripheral side of the bottom portion of the outer hook and the outer The electromagnetic induction means provided on the outer peripheral side of the side of the hook is driven simultaneously or alternately.

The electromagnetic induction means provided on the outer peripheral side of the bottom portion of the outer hook and the electromagnetic induction means provided on the outer peripheral side of the side portion of the outer hook may be driven simultaneously or alternately. In any case, the beneficial effects as described above are realized.
(4) Problem solving means of the invention of claim 4 In the problem solving means of this invention, in the configuration of the problem solving means of the invention of claim 1, 2 or 3, at the final stage of the water absorption process before reaching the temperature raising process. The temperature of the inner hook and the temperature between the inner hook and the outer hook are maintained at a temperature equal to or higher than a predetermined value.

  In this way, the temperature of the inner pot is maintained as high as possible at the end of the water absorption process, so the temperature rise of the inner pot after the transition to the temperature raising process is fast and the process proceeds smoothly to the temperature raising process. Can be made. As a result, the system for determining the total number in the temperature raising process is also increased.

  As a result of the above, according to the invention of this application, the dissolution of the outer peripheral rice film as in the prior art is avoided, the outflow of the contents is eliminated, the water absorption unevenness is eliminated, and the water absorption rate itself is improved. Can be cooked.

It is a top view which shows the structure of the rice cooker main body upper surface part of the electric rice cooker which concerns on embodiment of invention of this application. It is sectional drawing in the AA line cutting | disconnection part of FIG. 1 which shows the structure inside the rice cooker main body of the electric rice cooker which concerns on the embodiment. It is an expanded sectional view of the left half part (front part except a cover) of Drawing 2 which shows the composition inside the rice cooker main part of the electric rice cooker concerning the embodiment. Configurations of shoulder members, shoulder heater frames, shoulder heater covers, sliding packings for sealing, and metal plate portions in the rice cooker main body shoulder portion of the electric rice cooker according to the embodiment of the present invention shown in FIGS. FIG. The outer pot of the rice cooker body of the electric rice cooker according to the embodiment of the present invention shown in FIGS. 2 and 3, the second protective frame unit (upper), the first protective frame unit (lower), and the magnetic shielding It is an up-and-down exploded perspective view showing composition of each part of a board, the 1st and 2nd work coil, a ferrite core, and a coil stand. It is a block diagram which shows the structure of control circuit parts, such as the 1st, 2nd work coil, 3rd work coil, shoulder heater, and lid heater, of the electric rice cooker which concerns on embodiment of invention of this application. The flowchart which shows the control content of the 1st, 2nd work coil, 3rd work coil, shoulder heater, and lid heater in the water absorption process by the control circuit of FIG. 6 of the electric rice cooker according to the embodiment of the invention of this application. It is. The first and second work coils, the third work coil, the shoulder heater, and the lid heater in the temperature raising process to the unevenness process of the electric rice cooker according to the embodiment of the invention of this application in the control circuit of FIG. It is a flowchart which shows the control content.

It is a time chart corresponding to the control content of FIGS. 7-8 of the electric rice cooker which concerns on embodiment of invention of this application.

  Hereinafter, an example of a configuration of an embodiment for carrying out the invention of this application will be described in detail with reference to the accompanying drawings of FIGS.

First, in FIG. 1 to FIG. 9, the structure of a rice cooker main body of an electric rice cooker according to an embodiment of the invention of this application and the main part thereof are shown. The electric rice cooker in this embodiment has, as its basic features, a rice cooker body provided with a ceramic inner pot having an induction heating part on the outer peripheral surface of the bottom and an inner pot storage space in which the inner pot is stored. And a ceramic outer pot that is provided in the inner pot storage space of the rice cooker body and covers the inner pot from the bottom to the side, and is provided on the outer peripheral side of the bottom of the outer pot. Electromagnetic induction means for inductively generating heat at the induction heat generating portion on the outer peripheral surface of the bottom portion of the inner hook, an induction heat generating portion provided on the inner peripheral surface of the side portion of the outer hook, and provided on the outer peripheral side of the side portion of the outer hook. The electromagnetic induction means for inductively generating heat at the induction heat generating portion on the inner peripheral surface of the side portion of the outer pot, and a lid body that can be opened and closed at the upper portion of the inner pot storage groove of the rice cooker body. At least in the water absorption process, the electromagnetic The guide means is driven to cause the induction heat generating portion on the outer peripheral surface of the bottom portion of the inner hook to generate heat, and the electromagnetic induction means provided on the outer peripheral side of the outer pot is driven to move to the inner peripheral surface of the side portion of the outer pot. The induction heat generating portion provided is also induced to generate heat, thereby heating both the bottom and side portions of the inner hook.
<About the structure of the rice cooker body>
The rice cooker main body in the electric rice cooker according to this embodiment is, as shown in FIGS. 1 to 5, first, a bottomed cylindrical inner pot 3 made of a ceramic material containing rice and water (for example, a ceramic such as a clay pot). And a bottomed cylindrical outer pot 6 made of the same ceramic material covering the bottom 3a to the side 3c of the inner pot 3, and the outer pot 6 on the bottom side. A protective frame 4 forming an inner hook storage groove 5 for arbitrarily storing and setting the inner hook 3 via a hook 6, and a main body case 1 having a protective frame receiving space for receiving and holding the protective frame 4, The main body case 1 includes a lid 2 that is provided on the rear end side of the opening 5a of the inner hook housing groove 5 and opens and closes the opening 5a.

  The main body case 1 is composed of a synthetic resin side-side cylindrical outer case 1a and a synthetic resin bottom-side dish-shaped bottom case 1b. A synthetic resin, which will be described later, is placed inside the upper end of the outer case 1a. A shoulder member 8 made of resin is provided, and the protective frame 4 forming the inner hook housing groove 5 is connected and supported via the shoulder member 8. An edge 84 having an inverted U-shaped outer peripheral side cross section of the shoulder member 8 is engaged with the entire circumferential direction so as to be engaged with the engaging edge 10 having a bowl-shaped cross section on the upper end side of the outer case 1a. Yes.

  The protective frame 4 is composed of two upper and lower housing members, each of which is a synthetic resin molded first and second separate protective frame unit (lower unit) 4A and second protective frame unit (upper unit) 4B. The second protective frame unit 4B constituting the upper housing is laminated on the upper part of the first protective frame unit 4A constituting the lower housing, and is integrally formed.

  First, the first protective frame unit 4A constituting the lower housing includes a bottom portion 41a formed of a flat circular surface having a predetermined radius, and a predetermined height upward while gradually increasing the diameter from the outer periphery of the bottom portion 41a. A bent portion 41b extending in the direction of the curved portion 41b, a stepped portion 41c having a curved cross section formed on the upper edge of the bent portion 41b in a radially outward direction, and rising substantially vertically from the outer peripheral portion of the stepped portion 41c. The support wall 41d is formed with a cylindrical wall having a predetermined height. And this 1st protection frame unit 4A part is supported by the lower side coil stand 9 which mentions the bottom part 41a and the curved part 41b part later.

  Next, the second protective frame unit 4B constituting the upper housing is centered on a cylindrical wall 42b having a U-shaped cross section that is open outward in the radial direction, with a lower end on the lower side. A mounting portion 42a on the support wall 41d of the first protective frame unit 4A is provided, and a hook-like engagement step portion 42d that is enlarged outward in the predetermined radial direction is provided on the upper end side thereof. . An upper portion (substantially upper half portion) partitioned by the rib 42c on the outer peripheral surface of the cylindrical wall 42b of the second protective frame unit 42B is an installation surface (coiled surface) of a third work coil C3 described later. And a third work coil C3 wound in two layers inside and outside is installed on the work coil installation surface.

  It should be noted that the installation surface of the third work coil C3 is not the entire vertical width of the cylindrical wall 42b, but, for example, the upper half portion, so that the lower first protective frame unit 4A is even a little. This is because the distance to the second work coil C2 on the side is enlarged to avoid mutual induced interference.

  The first and second protective frame units 4A and 4B are stacked and integrated vertically as shown in FIGS. 2 and 3, so that the protective frame 4 formed as a whole with a bottomed cylindrical structure is provided. On the bottom upper surface side (the upper surface side of the bottom portion 41a and the curved portion 41b of the first protective frame unit 4A), the bottom portion 6a and the curved portion 6b of the outer pot 6 made of the ceramic material are partially disposed in the radial direction. The upper portion of the ceramic outer pot 6 is pasted with a predetermined heat-insulating air layer maintained on a portion having a predetermined thickness and an adhesive portion (not shown) and without adhesive. For example, as shown in FIG. 4, the first and second induction heating elements G1 and G2 made of silver paste or silver spray are provided on each of a circular flat bottom 3a and a curved portion 3b on the rounded surface. The same circular bottom 3a of the inner pot 3 and its Flexure 3b on the rounded surface of the outer periphery is adapted to be accommodated while maintaining a predetermined clearance S.

  Then, in the same storage state, for example, as shown in FIGS. 2 and 3, the upper end of the side portion 6c is extended to the upper portion of the side portion 3c of the inner hook 3. The outer hook 6 sufficiently covers the bottom 3 a of the inner hook 3 to the vicinity of the side 3 c.

  By the way, the outer hook 6 of this embodiment has a bowl-like structure as a whole, and the center of the flat circular bottom portion 6a corresponds to the center sensor fitting hole 10a at the center of the first protective frame unit 4A. The sensor part insertion hole 6e of the center sensor is provided, and the sensor part above the center sensor CS fitted in the center sensor fitting hole 10a is inserted in a loosely fitted state so as to be movable up and down. On the radially outer peripheral side, a hill for fitting high pedestal support members 61, 61,... Made of a heat-resistant elastic member such as silicon rubber for supporting the high pedestal 3e of the inner hook 3 at a predetermined interval in the circumferential direction. Portion supporting member fitting holes 6f, 6f... Are provided. Further, from a heat-resistant elastic member such as silicon rubber that supports the outer periphery of the bent portion 3b of the inner hook 3 at a predetermined interval in the circumferential direction at a portion near the outer periphery of the bent portion 6b at the upper outer peripheral side. Centering support member fitting holes 6g, 6g,... For fitting the centering support members 62, 62,.

  In each of the fitting holes 6f, 6f, 6g, 6g,..., High base support members 61, 61,..., Centering support members 62,. .. Are respectively fitted and fixed to support the bottom portion 3a and the bent portion 3b of the inner hook 3, but the hill portion supporting members 61, 61,... Are provided on the lower first protective frame unit 4A. Are supported in a stable fixed state between the pocket portions P, P,... And the upper portion 3e portion of the outer periphery of the bottom portion 3a of the inner hook 3 is placed in a state where it abuts downward from above, as will be described later. When the protective frame 4 and the outer hook 6 that are elastically supported so as to be movable up and down via the floating support mechanism are lowered according to the weight of the inner hook 3, the outer peripheral side flange portion F of the opening 3d of the inner hook 3 is moved. On the inner edge 82 portion of the shoulder member 8 to be described later The inner hook 3 is hooked uniformly over the entire circumferential direction through the heat-resistant support member, and the protective frame 4 side first and second work coils C1, C2 and the first The second induction heat generating portions G1 and G2 are opposed to each other through an appropriate positional gap and through an appropriate induction gap, and an appropriate predetermined gap (heat storage / convection space) is formed between the outer induction heat sink 6 and the outer pot 6. ) Supported with S maintained.

  At the same time, the opposing position and the corresponding distance between the third induction heat generating portion G3 on the inner peripheral surface of the side portion 6c of the outer hook 6 and the side portion 6c portion of the inner hook 3 that are induction-heated by the third work coil C3. Is also maintained at an appropriate design position and design distance.

  On the other hand, the centering support members 62, 62,... On the outer peripheral side of the bent portion not only support the inner hook 3 in the protective frame 4 in an appropriate positional relationship via the outer hook 6 after being stored, The outer periphery of the bent portion 3b of the inner hook 3 stored at the time is guided in the entire periphery so as to be stored in an accurate positional relationship, and the centering function is properly performed.

  Further, the protruding dimensions of the hill support members 61, 61... And the centering support members 62, 62... To the inner side of the outer hook 6 are such that the inner hook 3 is properly fitted in the protective frame 4 as described above. 2 and 3 that are stored and set in a positional relationship, the dimensions are set so as to form an appropriate gap S between the outer peripheral surface of the inner hook 3 and the inner peripheral surface of the outer hook 6.

  As a result, in the storage state of the inner hook 3 shown in FIGS. 2 and 3, the bottom portion 3a and the bent portion 3b of the inner hook 3 are heated by the heat generated by the first and second induction heating portions G1 and G2. The side portion 3c where the temperature is locally high and the heat at the same time is gradually conducted from the bottom portion 3a and the bent portion 3b side to the upper side portion 3c through the inside of the wall, and no induction heating portion is provided. The temperature on the side also increases gradually.

  Further, in the above configuration, in addition to this, the ceramic outer hook 6 is also provided inside the protective frame 4 in which the inner hook 3 is accommodated, and the first and second induction heating portions G1 and G2 are connected to each other. The outer periphery of the inner pot 3 is covered with the outer pot 6 made of ceramic, so that the bottom 3a of the inner pot 3 and the induction heating parts G1 and G2 of the bent part 3b and the vicinity of the induction heating parts G1 and G2 are outward. The heat radiated to the outer pot 6 is cut off by the outer pot 6 made of the same ceramic, and the radiant heat radiated outward from the induction heating section G1 of the bottom 3a of the inner pot 3, the induction heating section G2 of the bent section 3b, and the vicinity thereof. Heats the inner hook 3 itself in such a way as to envelop the outer periphery of the inner pot 3, and the same heat is stored in the opposing surface portion between the outer hook 6 and the inner hook 3 and the gap S between them. The hot air heated in the state is Bottom 3a of the inner hook 3 through S, increases from the outer peripheral surface side of the curved portion 3b on the outer peripheral surface of the side portion 3c, the whole of the inner hook 3 the outer peripheral surface heating, so heated.

  As a result, the inner hook 3 reaches a relatively high temperature from the bottom 3a and the bent portion 3b side to the entire side portion 3c, and effectively stores the amount of heat. Therefore, the amount of heat generated in the first and second induction heat generating portions G1 and G2 can be used effectively.

  Furthermore, in the case of the configuration of this embodiment, in that case, a third induction heat generating portion G3 is provided on the inner peripheral surface of the side portion of the outer hook 6 and corresponds to the third induction heat generating portion G3. A third work coil C3, which is electromagnetic induction means for inductively generating heat from the third induction heat generating part G3, is provided on the outer periphery of the side wall of the protective frame 4, and the side part 6c of the outer hook 6 is Heating is performed from the inner peripheral surface side.

  Accordingly, the ceramic outer hook 6 not only simply covers the outer periphery of the bottom 3a side of the inner hook 3 so as not to release heat, but also heats itself to a high temperature. Radiation heat from the hook 6 actively heats the inner inner pot 3 at a close distance with a slight gap S, and the inner pot 3 is not only on the bottom side but also on the side that has been underheated conventionally. The whole including 3c is effectively heated and heated. In this case, since the distance between the third work coil C3 and the third induction heating part G3 is short, the induction efficiency of the third induction heating part by the third work coil C3 is high, and noise is hardly generated.

  Moreover, the heating of the side portion 3c portion of the inner hook 3 is different from the case where the induction heating portion is directly provided in the side portion 3c portion of the inner hook 3, for example, and is heated at a predetermined distance from the outer pot 6 side. Since the inner hook 3 is heated by the radiant heat from the entire side portion 6c of the outer pot 6, the heating state becomes uniform, and the side portion of the inner pot 3 is heated. There is no possibility of causing scorching due to local heating as in the case of heating by directly providing an induction heating part in 3c and the like.

  In addition, in the case of this embodiment, the side portion 6c of the outer hook 6 is highly extended to the vicinity of the upper portion of the side portion 3c of the inner hook 3, and is located on the inner peripheral surface of the side portion 6c extended to be high. The third induction heat generating part G3 is provided, and a third work coil C3 for inductively generating heat by the third induction heat generating part G3 is provided on the outer periphery of the side wall of the protective frame 4 corresponding to the third induction heat generating part G3. Is provided.

  Therefore, in the ceramic outer hook 6, the inner peripheral surface of the side portion 6c extended to a position corresponding to the upper portion of the side portion 3c of the inner hook 3 is efficiently heated to become a high temperature. The upper portion of the side portion 3c of the inner pot 3 which has been underheated is also effectively heated, and the entire inner pot 3 including the side portion 3c and the upper portion thereof is effectively heated and heated. Thus, the space portion of the upper part of the rice in the inner pot 3 is maintained at a high temperature state (near 120 ° C.) similar to the case of rice cake.

In this case, the upper position of the side portion 3c of the inner pot 3 where the side portion 6c of the outer pot 6 where the third induction heat generating portion G3 is provided is determined, for example, from the rated rice cooking capacity of the electric rice cooker. It corresponds to the upper position vicinity (position above the position of the water at the time of water absorption) of the rice after completion of cooking. When doing so, it is possible to appropriately apply a sufficient and sufficient amount of heat similar to the case of rice cake to the cooked rice and its upper space position after completion of cooking determined from the rated rice cooking capacity of the electric rice cooker. Thus, it becomes possible to cook more delicious rice without causing uneven cooking without causing burning.
<About floating support structure of protective frame>
As described above, the protective frame 4 in this embodiment is configured by vertically integrating the first and second protective frame units 4A and 4B. The first protective frame unit 4a includes, for example, It is floatingly supported on the above-mentioned bottom case 1b via a floating support mechanism provided with a coil spring, and can be raised and lowered within a predetermined vertical dimension range.

  On the other hand, the second protective frame unit 4B is also raised and lowered in the same manner as shown in FIGS. 2 and 3 mounted on the upper portion of the first protective frame unit 4A. As a result, the bowl-shaped outer hook 6 housed and installed in the bottomed cylindrical protective frame 4 composed of the first and second protective frame units 4A and 4B is also used for the first and second protective frame units. It moves up and down with 4A and 4B in the same manner (see arrows in FIG. 3).

  Therefore, when the inner pot 3 containing water and rice is stored on the outer pot 6 via the high platform support members 61, 61,... And the centering support members 62, 62,. According to the weight, the protective frame 4 and the outer hook 6 are lowered together with the inner hook 3 by a predetermined dimension, and the lower surface of the flange portion F at the outer end of the opening 3d of the inner hook 3 is connected to the opening 5a of the inner hook housing groove 5. The heat-resistant support member part on the inner peripheral edge part 82 of the shoulder member 8 is formed and supported in a state of being suspended from the part.

  As a result, in the case of this embodiment, the inner hook 3 provided with the first and second induction heat generating parts G1 and G2 on the bottom side is the first provided with the first and second work coils C1 and C2. The third work coil C3 and the third induction heating part G3 of the second protection frame unit 4B provided with the first and second work coils C1 and C2 and the third work coil C3 of the protection frame unit 4A The third induction heat generating part G3 of the outer pot 6 provided is set at an appropriate position and dimensional relationship.

At this time, the hill support members 61, 61... And the centering support members 62, 62... Set an appropriate gap S between the outer hook 6 and the inner hook 3, and the centering support members 62, 62. ·· fulfills the centering function of the inner hook 3 during storage as described above.
<About the seal structure of the clearance for lifting>
By the way, when the protective frame 4 and the outer pot 6 are made floating with respect to the rice cooker body as described above, and the lifting space D is formed between the shoulder member 8 and the upper end 6d of the side portion 6c of the outer pot 6, There is a risk that heat between the inner hook 3 and the outer hook 6 escapes from the ascending / descending space D to the outside, water on the outer periphery of the inner hook 3 may invade, and the inner pot housing groove 5 does not look good. There are problems such as.

  Therefore, in this embodiment, they are assembled on the inner peripheral edge side of the metal plate 32, 32 for reinforcing the shoulder heater frame 31 and the shoulder heater cover 30 with respect to the shoulder member 8 described above on the upper side of the lifting space D. Thereafter, for example, as shown in FIG. 3, the shoulder member 8 and the outer hook 6 are extended by a predetermined dimension on the inner peripheral surface side (opening inner peripheral surface side) of the upper end 6d of the side portion 6c of the lower outer hook 6. A skirt-like sliding packing 35 is attached to seal the elevating space D between the upper portion 6d and the side portion 6c in the inner and outer directions over the entire circumferential direction, and above the protective frame 4 and the outer hook 6. When the shoulder member 8, the shoulder heater frame 31, the shoulder heater cover 31, the sliding packing 35, and the metal plates 32, 32 are overlapped and connected and integrated, the skirt portion of the sliding packing 35 (for sealing) Edge) 35b is the side of the outer hook 6 It is adapted to slidably inscribed with the inner circumferential surface of the c of the upper end 6d.

The packing 35 is provided with a fixing portion 35a fixed between the metal plates 32 and 32 and the shoulder heater cover 30 on the upper side of the skirt portion 35b. The fixing portion 35a is used to fix the packing 35. It is attached as shown in FIG.
Yes.
<Installation of shoulder heater at shoulder>
As described above, the opening 5a of the inner pot storage groove 5 in the rice cooker main body of this embodiment has the shoulder member 8 fitted and fixed to the inner peripheral edge of the upper end 1c of the main body outer case 1a, and the shoulder. It consists of a shoulder heater cover 30 and a shoulder heater frame 31 that are connected and fixed from the lower side through metal plates 32 and 32 and a packing 35 inside the inner peripheral portion of the member 8. In addition, a U-shaped structure opened outward in the radial direction is provided, and a shoulder heater H1 made of, for example, a code heater is provided on the entire outer circumferential surface. When the shoulder heater H1 generates heat, for example, as shown in FIG. 3, a thick heat keep inward in the radial direction at the opening 3d of the corresponding inner hook 3 in the storage state in the inner hook storage groove 5 as shown in FIG. The lower part of the part HK is efficiently heated to prevent the occurrence of dew in the part, thereby preventing the occurrence of white blurring of rice.
<About the configuration of the coil stand>
On the other hand, on the lower side of the protective frame 4 configured as described above (the lower side of the first protective frame unit 4A), a synthetic resin dish-shaped coil base 9 that supports the bottom of the protective frame 4 is provided. Is provided. For example, as shown in FIG. 9, the coil base 9 is positioned on the upper surface side in the circumferential direction 4, and the first and second work coils C <b> 1 on the outer peripheral surface side of the first protective frame unit 4 </ b> A. , Ferrite core housing grooves 9a, 9a,... Extending in the radial direction corresponding to C2 are provided, and the first and second ferrite core housing grooves 9a, 9a,. .. Are accommodated for the work coils C1, C2. The first and second work coils C1, C2 are supported in four directions by the upper surfaces of the ferrite core housing grooves 9a, 9a,. Then, the first protective frame unit 4A and the coil base 9 are connected and fixed to each other using a connecting portion on the outer peripheral side.

Further, on the outer peripheral side of the lower part of the coil base 9, four leg portions 9b, 9b,... Are provided downward corresponding to the positions of the ferrite core housing grooves 9a, 9a,. The leg portions 9b, 9b,... Are supported by floating support mechanisms 63, 63,... Provided on the bottom case 1b. A center sensor body fitting opening 9c is provided in the center of the coil base 9 so as to be concentrically penetrated with the center sensor fitting hole 10a on the first protective frame unit 4A side. -The center sensor CS composed of an inner pan temperature detection sensor such as a thermistor is moved upward from below in a state that it can be moved up and down through the sensor body fitting opening 9c and is always upwardly biased by a coil spring. It is installed so as to face.
<About the configuration of the lid>
On the other hand, the lid body 2 covering the opening 5a of the inner pot storage groove 5 of the rice cooker main body has a name plate 20 constituting the upper outer peripheral surface thereof and an upper surface as shown in FIGS. A synthetic resin upper plate 21 having a supporting surface portion of the nameplate 20 and a concave portion 21a for installing a microcomputer board or the like on the side front portion and constituting a central housing portion of the lid body 2 including the peripheral wall portion 21b; The lower plate 22 made of the same synthetic resin provided on the inner side (lower side) of the upper plate 21 and the first recess made of rubber on the concave portion 22b of the lower surface of the center portion of the main body portion 22a of the lower plate 22 A heat sink 23 made of metal having a lid heater H2 (see FIG. 6 / not shown in FIG. 2) that is fitted and fixed from below via a packing 25, and provided below the heat sink 23, A rubber-made second packing 14 is attached to the outer peripheral edge via a removable frame member 27 made of synthetic resin. They are formed from attached metal inner cover 24.

  As described above, the outer packing 14 portion of the inner cover 24 is detachably fitted and attached to the inner cover fitting recess 22b provided on the outer peripheral side of the central portion of the lower plate 22 from the lower side. . Further, the outer peripheral side edge 22c portion of the lower plate 22 is engaged with the lower end side inner peripheral surface portion of the peripheral wall 21c portion of the upper plate 21 having a predetermined vertical width.

  By the way, in order to increase the pressure resistance strength, the outer peripheral side portion of the rear end portion of the main body portion 22a of the lower plate 22 serving as the center is locked to the connecting piece on the hinge unit 11 side via a connecting piece, a screw or the like. At the same time, on the upper surface of the main body portion 22a of the lower plate 22, a metal reinforcing plate having a predetermined thickness, a predetermined structure, and a large number of reinforcing ribs are provided across the left and right and front and rear. The whole is formed into a high-strength structure.

  That is, the lower plate 22 has an intermediate portion of the outer periphery on the rear end side of the main body portion 22a bent upward and houses the above-described hinge unit 11 on the inner side, and on the outer end side thereof. The descending portion covers the hinge unit 11.

  And the rear-end side outer periphery of the main-body part 22a of these lower plates 22 is made into the bracket for attachment, The said lid body 2 has the rear-end side via the hinge unit 11 with respect to the shoulder member 8 of the said rice cooker main body upper part. A locking and unlocking mechanism 13 that engages with a predetermined position of the lid body 2 to open and close the lid body 2 in the vertical direction is provided on the open end side (front end side). Is provided.

Furthermore, the outer periphery 21b of the upper surface forming the nameplate support surface portion of the upper plate 21 is a curved surface whose outer diameter is gradually enlarged from the upper side to the lower side, and the lower end side thereof is the peripheral wall portion 21c described above. Are integrated with each other via a nameplate fitting groove (U-shaped groove). And the nameplate 20 which forms the transparent window 60c corresponding to the operation panel 60 surface and the liquid crystal panel 60A as shown in FIG. 1 is formed into a shape corresponding to the support surface shape of each part of the upper plate 21. The nameplate fitting grooves on the outer periphery of the upper plate 21 are integrated and integrated in a substantially flush state. Further, a transparent synthetic resin transparent sheet 80 is attached to the upper surface of the nameplate 20.
<Configuration of pressure adjustment mechanism in lid part>
In this embodiment, it shows about the case where it applies to a pressure type electric rice cooker as an example, and in the approximate center part of the above-mentioned lid 2, only steam is escaped to the outside while recovering the viscous component, and in the rice cooking process Accordingly, a pressure adjusting unit 26A for adjusting the pressure in the inner hook 3 in a plurality of stages is provided.

The pressure adjusting unit 26A is configured by, for example, steam escape passages 50, 50a to 50c that are detoured from the inner pot 3 toward the outside, and pressure adjusting mechanisms provided in the steam escape passages 50, 50a to 50c (this A plurality of pressure regulating units 26A are actually provided, but in the case of this embodiment, since it is not an essential configuration, the details thereof are omitted).
<About the configuration of the operation panel and display panel on the top of the lid>
Reference numeral 60 in FIG. 1 denotes an operation panel. The operation panel 60 includes a substrate having a predetermined depth and a liquid crystal panel storage box on the back side of the panel portion, and includes a microcomputer as a rice cooking and heat retention control means. The microcomputer board 60B and the liquid crystal panel 60A are fitted and housed in the opening of the upper plate 21 and the groove of the middle plate 20.

The central portion has a transparent window 60C corresponding to the display surface of the liquid crystal panel 60A. Around the transparent window 60C, a rice cooking reservation switch SW1, a rice cooking switch SW2, a heat retention switch SW8, and a cancel switch are provided. SW3, menu switches SW5 (return), SW6 (recommend), hot spring selection switch SW4, voice guide SW7, voice guide SW7, clock and timer selection menu Various operation keys of the time / minute setting switch SW9 and a human sensor MS for human detection are provided.
(Regarding the configuration of the control circuit such as the first and second work coils C1 and C2, the third work coil C3, the shoulder heater H1, and the lid heater H2)
Next, FIG. 6 shows the first and second work coils C1, C2 for heating the bottom side of the inner hook 3, and the side 3c side of the inner hook 3 indirectly through the outer hook 6 and the heat storage space. Driving state (ON, etc.) of the third work coil C3 to be heated, the shoulder heater H1 to heat the opening peripheral edge (heat keeping part HK) of the inner hook 3 and the lid heater H2 to heat the heat radiating plate 23 inside the lid 2 OFF), the configuration of the control circuit for controlling the drive output (duty ratio) is shown.

This control circuit is configured with a microcomputer control unit MU as the center, and the microcomputer control unit MU detects the temperature of the bottom 3a of the inner pot 3 described above in each of the steps of water absorption, unevenness and heat retention. Input the detection temperature T2 of the CS, the detection temperature T1 of the lid sensor HS that detects the temperature in the upper part of the inner pot 3, and the detection temperature T0 of the room temperature sensor RS that detects the room temperature to heat the bottom side of the inner pot 3 The first and second work coils C1, C2, the third work coil C3 for heating the side 3c side of the inner hook 3, and the shoulder heater for heating the peripheral edge of the opening (heat keeping part HK) of the inner hook 3 The drive state (ON, OFF) and drive output (duty ratio) of each of the lid heaters H2 for heating the heat sink 23 inside the H1 and the lid 2 are appropriately controlled.
(About water absorption heating control in the water absorption process)
Next, FIG. 7 and FIG. 8 are a flowchart showing a control sequence of the water absorption heating control in the water absorption process to the unevenness process according to the embodiment of the invention of this application, and FIG. 9 is a time chart showing the control sequence.

  In the case of the electric rice cooker in the embodiment of the invention of this application, as described above, the inner pot 3 is a ceramic material, and once it is heated to a high temperature state, the heat storage power (heating power based on the heat storage amount) is large. Since the specific heat is small, it takes time to reach a high temperature state, and since the heat conductivity is small, there is a characteristic that even if a part is heated, the heat is hardly transmitted to the whole.

  Moreover, since the inner hook 3 is only provided with the induction heat generating portions G1 and G2 on the outer peripheral surface of the bottom portion 3a and the outer peripheral surface of the bent portion 3b extending from the bottom portion 3a to the side portion 3c, the bottom portion 3a and the bent portion 3b are If a certain amount of time is taken, the temperature becomes considerably high, but heat is hardly transmitted to the side portion 3c, and the temperature increase rate of the side portion 3c is considerably low.

  Therefore, the heating power of the first and second work coils C1 and C2 from the water absorption process to the cooking process through the temperature raising process, especially in the water absorption process, until the temperature rising process is reached. Even if it is increased, the temperature of the bent portion 3b on the outer periphery of the bottom portion 3a and the bottom portion 3a only increases locally, and the temperature on the side portion 3c side does not readily increase.

  Thus, in the situation where the temperature on the bottom 3a side is high and the temperature on the side 3c side is low, as described above, the lower skin of the rice melts and the contents flow out and stick to the bottom of the inner pot. As a result, uneven water absorption occurs. Also, the rice will not move and will cause burns.

  On the other hand, since the temperature of the side part of the inner pot is low, the heating amount of the upper rice and water is not sufficient, and the effective water absorption effect cannot always be improved. Therefore, water absorption unevenness is more likely to occur.

  Therefore, in the configuration of the embodiment of the invention of this application, for example, as shown in the flowcharts of FIGS. 7 to 8 and the time chart of FIG. The first and second work coils C1 and C2 are driven to cause the induction heat generating portions G1 and G2 on the outer peripheral surface of the bottom portion 3a of the inner hook 3 to be inductively heated and provided on the outer peripheral side of the side portion 6c of the outer hook 6. The third work coil C3 is driven to induce induction heat generation in the induction heat generating portion G3 provided on the inner peripheral surface of the side portion 6c of the outer hook 6, whereby the bottom 3a side and the bent portion 3b side of the inner hook 3 are provided. The side portion 3c of the inner pot 3 can be effectively and uniformly heated without particularly increasing the heating amount of the portion, so that the conventional problems as described above are solved, and the water absorption performance is as much as possible. I try to improve.

  That is, when the predetermined rice cooking menu is set and the rice cooking switch SW2 is pressed while the AC power is on, rice cooking control by the microcomputer control unit MU described above is started.

  And first, while setting each part to be controlled within a predetermined processing time (1 minute) after the start of rice cooking, the detected temperature T0 of the room temperature sensor RS, the detected temperature T1 of the lid sensor HS, the center sensor CS detection temperature T2 and the like are input and stored.

  Next, it is determined whether or not the predetermined processing time of 1 minute has passed (step S1). As a result, if YES, the water absorption process is entered. The water absorption process of this embodiment includes a water absorption process 1 at a set time t1 and a water absorption process 2 at a set time t2, as shown in FIG. Therefore, first, water absorption step 1 is entered. When the water absorption process 1 is entered, it is first determined in step S2 whether or not the temperature T2 detected at the bottom of the inner hook 3 by the center sensor CS is equal to or higher than the water absorption target temperature 35 ° C. If the result is YES, the process proceeds to the determination of the lid sensor temperature T1 in step S6. If the temperature T2 of the bottom portion 3a of the NO inner pot 3 is not 35 ° C. or higher, first, in step S3. Then, it is determined whether or not the detection temperature T1 detected by the lid sensor HS has reached the target water absorption temperature of 35 ° C.

  As a result, in the case of YES, the process proceeds to step S4, and the first and second work coils C1, C2 of the bottom portion 3a of the inner hook 3 and the bent portion 3b are driven at a duty ratio of 3-7, The third work coil C3 corresponding to the side 3c of the inner hook 3 is driven at a duty ratio of 6 to 10, and the shoulder heater H1 corresponding to the outer peripheral edge of the opening of the inner hook 3 is driven to the duty ratio. While driving at 0-8, the lid heater H2 that heats the heat sink 23 of the lid 2 is driven at a duty ratio of 6-12, thereby quickly detecting the temperature T2 detected by the center sensor CS and the lid sensor HS. Heating control is performed so that the detected temperature T1 becomes the target water absorption temperature of 35 ° C. in the water absorption step 1 respectively.

  Thus, in the water absorption process, the first and second work coils C1, C2 of the bottom 3a and the bent portion 3b of the inner hook 3 are driven with a relatively small duty ratio of 3-7, When the third work coil C3 corresponding to the side portion 3c of the hook 3 is driven at a duty ratio 6 to 10 sufficiently larger than that, the local portion in the bottom portion 3a portion of the inner hook 3 as in the prior art is obtained. Heat causes the rice skin in the inner lower layer of the inner pot 3 to melt and the contents to flow out and stick to the bottom of the inner pot, resulting in uneven water absorption, and the rice will not move and will be burnt. The problem of causing a problem is solved.

  Moreover, in the case of the electric rice cooker of this embodiment, the side part 3c part of the inner pot 3 is surrounded by the side part 6c of the outer pot 6, and the side part 3c of the inner pot 3 of the outer pot 6 is also surrounded. Is provided with a third induction heat generating portion G3, and this third induction heat generating portion G3 is inductively heated by the third work coil C3 on the outer peripheral side of the outer hook 6. ing. Therefore, the side portion 3c of the inner hook 3 is directly exposed to the radiant heat from the third induction heat generating portion G3 on the inner peripheral surface of the side portion 6c of the outer hook 6, and the outer pot heated by the third induction heat generating portion G3. The entire circumference of the side portion 3c is uniformly and efficiently heated through the heat storage space having a high heat storage temperature by the radiant heat from the entire side portion 6c of the six.

  Therefore, even in the adjustment stage to the water absorption target temperature in the initial stage of the water absorption process, there is no uniform and efficient heating means corresponding to the side portion 3c of the inner hook 3 as in the prior art. Since the water absorption temperature is low, the amount of heating of the upper rice and water is not sufficient, and the problem of uneven water absorption can be solved effectively and the water absorption target temperature can be quickly adjusted to 35 ° C.

  On the other hand, when the detection temperature T1 of the lid sensor HS determined to be YES in the determination of the step S3 becomes 35 ° C., the first and second of the bottom portion 3a of the inner hook 3 and the bent portion 3b. The work coils C1 and C2 are driven at a duty ratio of 3 to 7, and the third work coil C3 corresponding to the side portion 3c of the inner hook 3 is driven at a duty ratio of 6 to 10 larger than that. Driving, the shoulder heater H1 corresponding to the outer peripheral edge of the opening of the inner hook 3 is driven at a duty ratio of 0 to 8, while the driving of the lid heater H2 for heating the heat radiating plate 23 of the lid 2 is stopped. Thus, the heating control is quickly performed so that the detection temperature T2 detected by the center sensor CS and the detection temperature T1 detected by the lid sensor HS respectively become the target water absorption temperature 35 ° C. in the water absorption process 1.

  On the other hand, as a result of the heating control in steps S2 to S5, if the detected temperature T2 of the center sensor CS is 35 ° C. or more and YES in step S2, the detected temperature T1 of the lid sensor HS is further determined in step S6. It is determined whether or not the temperature has reached 35 ° C. As a result, in step S6, the detected temperature T2 of the center sensor CS of NO is 35 ° C. or higher, but if the detected temperature T1 of the lid sensor HS has not yet reached 35 ° C., the other step Proceeding to S7, the driving of the first and second work coils C1 and C2 of the bottom 3a and the bent portion 3b of the inner hook 3 is stopped, and heating using the heat storage force is performed. While preventing the temperature of the bottom portion 3a from increasing, the third work coil C3 corresponding to the side portion 3c of the inner hook 3 is driven at the same large duty ratio 6 to 10, and the opening of the inner hook 3 is maintained. By driving the shoulder heater H1 corresponding to the outer peripheral edge with a duty ratio of 0 to 8, and driving the lid heater H2 for heating the heat radiating plate 23 of the lid 2 with a duty ratio of 6 to 12, The temperature T1 detected by the lid sensor HS is quickly absorbed by the water absorption process. Heating control so that the target water temperature 35 ° C. in.

  On the other hand, when the detected temperature T1 of the lid sensor HS eventually reaches the target water absorption temperature 35 ° C. by these controls, it is determined in step S6 that the same state is reached (YES). Then, the process proceeds to step S8, and heat is stored from the bottom 3a side of the inner hook 3 while the driving of the first and second work coils C1, C2 of the bottom 3a and the bent portion 3b of the inner hook 3 is stopped. Only heating using the heat storage power of the space and the bottom of the inner pot is performed, and the temperature on the bottom 3a side of the inner pot 3 is not increased to a water absorption target temperature of 35 ° C. or higher. The corresponding third work coil C3 is driven as it is with a large duty ratio of 6 to 10, and the shoulder heater H1 corresponding to the outer periphery of the opening of the inner hook 3 is driven with a duty ratio of 0 to 8. On the other hand, the driving of the lid heater H2 for heating the heat radiating plate 23 of the lid 2 is stopped, and the temperature detected by the center sensor CS and the temperature T2 detected by the lid sensor HS become the target water absorption temperature 35 ° C. in the water absorption process 1. Control heating. As a result, the entire inner hook 3 in the water absorption process 1 becomes approximately 35 ° C., and a uniform water absorption heating state without local heating of the bottom is realized, and this state is continued for a predetermined set time t1.

  Next, it progresses to step S9 and progress of the set time t1 corresponding to the said water absorption process 1 is determined. As a result, if YES, the process proceeds to the water absorption step 2 in FIG. 9, and in step S10, the first and second work coils C1, C2 of the bottom portion 3a of the inner hook 3 and the bent portion 3b are connected to a duty ratio of 10. The third work corresponding to the side portion 3c of the inner hook 3 is driven with a large heating output increased in comparison with the water absorption step 1 of ~ 16 to increase the heating force from the bottom 3a side of the inner hook 3. The duty ratio of the coil C3 is reduced to 0 to 8 as compared with the case of the water absorption step 1, while the duty ratio of the shoulder heater H1 corresponding to the outer peripheral edge of the opening of the inner hook 3 is set to 0 to 0. 8. The duty ratio of the lid heater H2 that heats the heat radiating plate 23 of the lid 2 is maintained at 6 to 12, basically the detection temperature T2 by the center sensor CS and the detection temperature by the lid sensor HS. T1 becomes a temperature corresponding to the target water absorption temperature 35 ° C. in the water absorption process 1. However, the temperature of the inner pot 3 and the heat storage space around the inner pot 3 is generally increased so as to enable a smooth transition to the next temperature raising step. Will be described later).

  As a result, the water absorption efficiency at the end of the water absorption process is improved, the temperature increase rate after shifting to the temperature increase process is increased, and the combined number determination accuracy is also improved.

  Next, it progresses to step S11 and it is determined whether the predetermined set time t2 corresponding to the water absorption process 2 passed. Then, when the set time t2 of the water absorption process 2 of YES has elapsed, the process proceeds to the temperature raising process to achieve a smooth temperature rise of the inner pot temperature.

  In the case of this embodiment, the temperature raising step is composed of three steps: a temperature raising step 1 at a set time t3, a temperature raising step 2 at a set time t4, and a temperature raising step 3 at a set time t5. Then, as shown in steps S12 to S17 in the flowchart of FIG. 8 and the time chart of FIG. 9, first, in any case, in the temperature raising process 1 to the temperature raising process 2, the bottom 3a and the curve of the inner pot 3 are curved. The first and second work coils C1 and C2 of the portion 3b have a duty ratio of 10 to 16, and the third work coil C3 corresponding to the side portion 3c of the inner hook 3 has a duty ratio of 12 to 16. The shoulder heater H1 corresponding to the outer periphery of the opening of the inner hook 3 is driven with a duty ratio of 4 to 12 and the duty ratio of the lid heater H2 with an output close to full power of 0 to 8, respectively. .

  Then, when the set times t3 and t4 of each process have passed, respectively, the process proceeds to the temperature raising process 3. In the temperature raising step 3, the first and second work coils C1 and C2 of the bottom portion 3a and the bent portion 3b of the inner hook 3 correspond to the duty ratios 10 to 16 and the side portion 3c of the inner hook 3. The third work coil C3 is driven at a duty ratio of 12 to 16, the shoulder heater H1 corresponding to the outer periphery of the opening of the inner hook 3 is driven at a duty ratio of 4 to 12, and the lid heater H2 The duty ratio is increased to 12-16 and each is driven at full power.

  As a result, as is apparent from the time chart of FIG. 9, first, the output of the first and second work coils C1, C2 is first raised to the full power state at the stage of the water absorption process 2 as described above. Therefore, the temperature of the bottom of the inner pot 3 detected by the center sensor CS gradually increases from the stage of the water absorption process 2, and reaches the boiling temperature from the initial stage when the process proceeds to the temperature increase process 1, and the temperature rises. By the end of step 1, it will exceed 125 ° C. Correspondingly, the detection temperature T1 of the lid sensor HS also reaches the boiling temperature, and the boiling state is detected.

  On the other hand, in the water absorption step 2, since the output of the second work coil C3 is reduced, the ambient temperature T3 of the heat storage space between the inner pot 3 and the outer pot 6 is temporarily cut below 100 ° C. However, as a result of the output of the first and second work coils C1 and C2 being increased as described above, a new increase starts from the second half of the water absorption process 2, and the heating amount of all heating means is further increased. When entering the temperature raising step, the temperature is greatly increased from 150 ° C to 180 ° C.

  Therefore, in the case of this embodiment, the temperature rise process 1 to the temperature rise process 3 in which the boiling state is quickly reached and the boiling state is maintained, the entire inner pot 3 including the upper portion in the inner pot 3 is The fired rice is cooked as if it were wrapped in fire, and a very good heating state is achieved.

  Then, when the set time t5 of the temperature raising process 3 has elapsed, the process proceeds to the cooking process shown in steps S18 to S20. This cooking process includes a cooking process 1 at a set time t6 and a cooking process 2 at a set time t7, and the first and second work coils C1 of the bottom portion 3a and the bent portion 3b of the inner pot 3, respectively. C2 corresponds to a duty ratio of 6 to 16, and the third work coil C3 corresponding to the side portion 3c of the inner hook 3 corresponds to a duty ratio of 8 to 14, the outer peripheral edge of the opening of the inner hook 3. The shoulder heater H1 has a duty ratio of 4 to 12, and the lid heater H2 has a duty ratio of 12 to 16, and the outputs other than the outputs of the shoulder heater H1 and the lid heater H2 are reduced by a predetermined amount to control the heating. .

  In this case, in the temperature raising step as described above, the atmosphere temperature T3 of the heat storage space between the inner pot 3 and the outer pot 6 is heated to about 180 ° C., and the inner pot having a high heat storage power is made of ceramic. 3 is heated to a temperature close to 130 ° C., even if the outputs of the first and second work coils C1, C2 and the third work coil C3 are reduced to some extent as described above, the inner pot 3 The temperature of itself (refer to the change in the temperature T2 of the center sensor CS) and the temperature of the upper space in the inner hook 3 hardly decrease (see the change of the temperature T1 of the lid sensor HS). Therefore, it is possible to realize a good cooking function while reducing power consumption.

  In this way, when the set times t6 and t7 of the cooking steps 1 and 2 have elapsed (YES in step S19 and step S21), the extra cooking process of the set time t8 in step S22 is then performed and the extra rice in the rice Drain moisture. In this additional cooking process, the first and second work coils C1 and C2 of the bottom 3a and the bent portion 3b of the inner pot 3 correspond to the duty ratios 0 to 16 and the side 3c of the inner pot 3, respectively. The third work coil C3 to be used has a duty ratio of 6 to 12, the shoulder heater H1 corresponding to the outer peripheral edge of the opening of the inner hook 3 has a duty ratio of 4 to 12, and the lid heater H2 has a duty ratio. -Control heating with a ratio of 6-12.

  Furthermore, when the set time t8 in this additional cooking process has elapsed and YES is set in step S23, the process finally proceeds to the uneven process.

This unevenness process consists of two processes, an unevenness process 1 of steps S24 and S25 and an unevenness process 2 of steps S26 and S27. In either process, the bottom 3a and the bent portion 3b of the inner pot 3 are The duty ratio of the first and second work coils C1 and C2 is 0-4, which is smaller than the additional cooking step, while the duty ratio of the third work coil C3 corresponding to the side portion 3c of the inner pot 3 is set. -Although the tee ratio is smaller than that of the additional cooking process, but 4-10 larger than the first and second work coils C1, C2, the side 3c of the inner hook 3 and the upper space in the inner hook 3 The temperature of the section is raised, the evaporation of moisture from the rice during unevenness is promoted, the occurrence of scorching on the bottom side is prevented, and the shoulder heater H1 corresponding to the outer peripheral edge of the opening of the inner pot 3 is Tea ratio is 4-12, the lid heater The duty ratio of No. 2 is set to 6 to 12, which is the same duty ratio as the additional cooking process, and is controlled by heating so that the opening of the inner pot 3 and the inner side of the lid 2 are exposed to dew and white blur. Avoid the occurrence of
(Regarding the operation of the electric rice cooker and the water absorption control in the embodiment of the invention of this application)
In the electric rice cooker according to the embodiment of the invention of this application, as described above, the rice cooker provided with the ceramic inner pot having the induction heating portion on the outer peripheral surface of the bottom and the inner pot storage space in which the inner pot is stored. A main body, a ceramic outer pot that is provided in the inner pot storage space of the rice cooker main body and covers from the bottom to the side of the inner pot, and a bottom outer peripheral side of the outer pot. Electromagnetic induction means for inductively generating heat at the induction heat generating portion on the outer peripheral surface of the bottom portion of the inner hook through the hook, an induction heat generating portion provided on the inner peripheral surface of the side portion of the outer hook, and an outer peripheral side of the side portion of the outer hook. Provided with electromagnetic induction means for inductively generating heat at the induction heat generating portion on the inner peripheral surface of the side portion of the outer pot, and a lid body that can be opened and closed at the upper part of the inner pot storage groove of the rice cooker body, In the water absorption process, the electromagnetic induction means provided on the outer peripheral side of the bottom of the outer pot is driven to The induction heat generating part on the outer peripheral surface of the bottom of the hook is induced to generate heat, and the electromagnetic induction means provided on the outer peripheral side of the side of the outer hook is driven to induce the induction heat generating part provided on the inner peripheral surface of the side of the outer hook. By generating heat, the side portion of the inner hook is effectively heated without increasing the heating amount of the inner pot bottom.

  According to such a configuration, first, the bottom portion of the ceramic inner pot is heated by the induction heat generation of the induction heat generating portion on the outer peripheral surface of the bottom portion, and becomes high temperature, and the heat at the same temperature eventually goes from the bottom side to the side portion side. It is gradually conducted through the wall, and eventually the temperature on the side increases to a predetermined temperature.

  In this configuration, in addition to this, a ceramic outer hook is provided in the inner hook storage groove in which the inner hook is stored, and the outer hook is heated by the heat generated by the induction heat generating portion on the outer peripheral surface of the bottom. It is configured to cover from the bottom to the side of the inner pot where the temperature gradually increases.

  Therefore, the heat generated in the induction heat generating part at the bottom outer peripheral surface side of the inner pot and the radiant heat radiated outward from the outer peripheral surface of the inner pot whose temperature has been increased by the heat generated by the ceramic outer pot with extremely low thermal conductivity. Insulated and stored, heat is stored in the heat storage space between the inner and outer pots so as to wrap the outer periphery of the inner pot from the bottom of the inner pot, and the outer peripheral surface of the inner pot is heated and heated in the same heat storage state.

  In addition, high-temperature air between the inner pot and the outer pot heated and heated in the same heat storage state rises from the outer peripheral surface side of the inner pot to the outer peripheral surface side by the convection, and The side outer peripheral surface of the inner hook is heated and heated.

  As a result, the temperature of the inner pot rises relatively quickly from the bottom side to the entire side, and effectively stores the amount of heat corresponding to the temperature rise. Therefore, the amount of heat generated in the induction heating portion at the bottom of the inner hook can be effectively applied to the entire inner hook without wasting it, and the thermal efficiency is improved. As a result, it is possible to reduce the drive output of the electromagnetic induction means for inductively generating heat at the induction heating portion at the bottom of the inner hook.

  In addition, in the case of the configuration of the electric rice cooker according to the embodiment of the invention of this application, in that case, it is guided to the side inner peripheral surface of the outer pot that is further configured to wrap the side outer periphery from the bottom of the inner pot. A heat generating part is provided, and electromagnetic induction means for inductively generating the induction heat generating part is provided on the outer peripheral side of the outer hook corresponding to the induction heat generating part. The part is induction-heated from the inner peripheral surface side.

  Therefore, the ceramic outer hook not only covers the outer periphery of the inner hook so as not to let the heat from the inner hook side escape, but itself heats up to a high temperature. The hook side portion further positively heats the outer periphery of the inner hook side portion, and the side portion of the inner hook that has conventionally been insufficient in heating amount is effectively heated and heated. In addition, the heating of the side portion of the inner pot by the outer pot causes the radiant heat generated by the heat generated by the induction heating section on the inner peripheral surface of the outer pot and the inner circumference of the outer pot through the heat storage space between the inner pot and the outer pot. Because the radiant heat from the outer side of the outer pot that has become hot due to the heat generated by the induction heating section of the surface is effectively indirect heating, the heating action is much higher than indirect heating by the conventional side heater. However, the entire side portion of the inner hook is heated uniformly, and it is not necessary to cause scorching due to local heating as in the case where the induction heat generating portion is provided directly on the outer peripheral surface of the inner hook side portion.

  In the case of the same configuration, at least in the water absorption step, the electromagnetic induction means provided on the outer peripheral side of the bottom portion of the outer hook is driven to induce induction heat generation at the outer peripheral surface of the bottom portion of the inner hook, and the outer pot Without increasing the heating amount of the inner pot bottom, by driving the electromagnetic induction means provided on the outer peripheral side of the side and induction heating the induction heating part provided on the inner peripheral surface of the outer pot, The side portion of the inner hook is effectively heated.

  Therefore, the output of the electromagnetic induction means provided on the outer peripheral side of the bottom portion of the outer hook and the output of the electromagnetic induction means provided on the outer peripheral side of the side portion of the outer hook are controlled to a predetermined appropriate relationship, If the heat generation amount of the induction heat generating portion of the surface and the heat generation amount of the induction heat generating portion provided on the inner peripheral surface of the side portion of the outer pot are appropriately adjusted, the heating amount of the inner pot bottom portion is increased in the water absorption process. Without increasing the amount of heating at the side portion of the inner pot, it is possible to increase the heating temperature, and the entire area from the bottom side to the upper side of the rice in the inner pot can be absorbed uniformly at a uniform temperature. It becomes like this.

  As a result, due to local heating only on the bottom side as in the past, the rice skin melts and the contents flow out, sticking to the bottom of the inner pot, the problem of uneven water absorption, and the rice does not move, Problems such as burning can be reliably solved. Moreover, as a result of eliminating the water absorption unevenness, the water absorption efficiency is improved and the water absorption rate is reliably increased.

  Therefore, the finally cooked rice is also fluffy from the core, and it becomes a solid and delicious rice.

  1 is a rice cooker body case, 1a is an outer case, 1b is a bottom case, 2 is a lid, 3 is an inner pot, 3a is a bottom part, 3b is a bent part, 3c is a side part, 3d is an opening part, and 4 is a protective frame 4A is the first protective frame unit, 4B is the second protective frame unit, 5 is the inner hook storage groove, 6 is the outer pot made of ceramic, 6a is the bottom, 6b is the bent portion, 6c is the side portion, and 6d is Side upper end, 7 is a magnetic shielding plate, 8 is a shoulder member, 9 is a coil base, MU is a microcomputer control unit, C1 is a first work coil, C2 is a second work coil, C3 is a third work coil, G1 is the first induction heating unit, G2 is the second induction heating unit, G3 is the third induction heating unit, H1 is the shoulder heater, H2 is the lid heater, RS is the room temperature sensor, HS is the lid sensor, and CS is the center. It is a sensor.

Claims (4)

And ceramic inner hook having an induction heating section in the bottom peripheral surface, and a rice cooker body is the inner pot through the protective frame form a inner hook receiving groove to be housed, said inner pot receiving groove of the cooker body A ceramic outer pot that covers the inner pot from the bottom to the side, and an induction heat generated on the outer peripheral surface of the inner pot via the outer pot. Electromagnetic induction means for inductively generating heat, induction heat generating portions provided on the side inner peripheral surface of the outer hook, and induction heat generation on the side inner peripheral surface of the outer hook provided on the side outer peripheral side of the outer hook Electromagnetic induction means for inductively generating heat, and a lid body that can be opened and closed at the upper part of the inner pot storage groove of the rice cooker body, and in the water absorption step, provided on the outer peripheral side of the bottom of the outer pot While driving the electromagnetic induction means, the induction heat generating portion on the outer peripheral surface of the bottom portion of the inner hook is induced to generate heat, By induction heating the induction heating portion of the side inner peripheral surface of the outer holder and drives the electromagnetic induction means provided on the side outer circumferential side of Kigaikama, without increasing the heating amount of the inner pot bottom, An electric rice cooker characterized in that the side portion of the inner pot is effectively heated.   By increasing the output of the electromagnetic induction means provided on the outer peripheral side of the side of the outer hook to the output of the electromagnetic induction means provided on the outer peripheral side of the bottom of the outer hook, The electric rice cooker according to claim 1, wherein the amount of heat generated by the induction heat generating portion on the inner peripheral surface of the side portion of the outer pot is increased.   3. The electric rice cooker according to claim 1, wherein the electromagnetic induction means provided on the outer peripheral side of the bottom portion of the outer pot and the electromagnetic induction means provided on the outer peripheral side of the side portion of the outer pot are driven simultaneously or alternately. vessel.   The first and second water absorption steps before the temperature raising step are characterized in that the temperature of the inner pot and the temperature between the inner pot and the outer pot are maintained at a predetermined value or more. Or the electric rice cooker of 3.

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