JP4591231B2 - rice cooker - Google Patents

Description

  The present invention relates to a rice cooker.

The structure of the conventional common rice cooker is shown in FIG. In recent years, rice cookers that use electromagnetic induction heating and have a compact main body for convenience have become popular in the market. For example, as a conventional rice cooker, it was as shown in FIG. In FIG. 6, reference numeral 101 denotes a main body having a body 113 that forms an outline whose upper surface is open, and is covered with an openable / closable lid 102. A pan 103 is detachably housed inside the main body 101. The pan 103 is made of a magnetic material such as stainless steel or iron. The protective frame 104 is a storage part of the pan 103 and is formed in a bottomed cylindrical shape from a non-metallic material. A heating coil 105 for inductively heating the pan 103 is disposed outside the protective frame 104. The heating coil 105 includes an inner coil 106 disposed outside the bottom surface of the protective frame 104 and an outer coil 107 disposed on the outer periphery thereof.

  Further, a ferrite 108 is disposed outside the heating coil 105, thereby performing magnetic shielding to the outside (reducing magnetic flux leaking outside the rice cooker). Reference numeral 109 denotes a temperature sensor that measures the temperature of the pan 103. A heating control unit 110 drives and controls the heating coil 105. The heating control unit includes a high power element 112 such as a switching element or a rectifying element that generates a high voltage and a large current to supply high frequency power to the heating coil 105.

111 is an approximately cylindrical magnetic shield made of a conductive material (for example, aluminum). The magnetic shielding material 111 is provided on the outer peripheral side of the heating coil 105, and the upper and lower surfaces of the magnetic shielding plate 111 are positioned above and below the upper and lower surfaces of the heating coil 105, respectively. In the magnetic shield 111, an eddy current that cancels the magnetic field passing through the magnetic shield 111 is generated, thereby reducing the passage of magnetic flux. The magnetic shield 111 is a compact rice cooker that reduces the magnetic field (magnetic flux) leaking to the outside of the rice cooker, so that the magnetic flux leaking outside the heating coil 105 causes the main body 101 or a member in the vicinity of the main body 101. This prevents the occurrence of problems such as an increase in temperature or malfunction of an electrical product arranged near the main body 101 due to the influence of magnetic flux (see, for example, Patent Document 1).
Japanese Examined Patent Publication No. 4-36009

  However, in the conventional configuration, magnetic flux is also generated from the high power element 112 such as a switching element or a rectifying element provided in the heating control unit 110. However, the magnetic shield 111 prevents the magnetic flux generated from the heating coil 105 from leaking to the outside. Since they are arranged so as to be reduced, there has been a case where sufficient measures have not been taken regarding leakage of the magnetic flux generated from the high power element 112 to the outside of the main body 101.

  This invention solves the said conventional subject, and it aims at providing the rice cooker with high convenience, reducing the magnetic field (magnetic flux) which leaks outside from a rice cooker, making a rice cooker compact.

In order to solve the conventional problems, a rice cooker according to the present invention includes a rice cooker main body, a body constituting an outline of the main body, a pan detachably stored in the main body, and a heating coil for induction heating the pan. and heating control unit that controls the heating coil operation, and an annular magnetic shielding material to reduce the magnetic flux generated from the position to the heating coil on the side outward of the heating coil is discharged to the outside of the body, the magnetically shielded member The contact surface with the magnetic shielding material provided in the protective frame which is the pot housing portion of the main body is formed by a cylindrical rib, and is supported by the protective frame that elastically deforms and fixes the magnetic shielding material. The heating control unit is fixed to the protective frame and has a high power element, and the high power element is disposed inside the magnetic shielding material and within the height width. It is a rice cooker.

  As a result, not only the magnetic flux generated from the heating coil but also the magnetic flux generated from the high power element can be reduced by the magnetic shielding material, so that the magnetic flux leaking outside the main body can be reduced. The leaking magnetic field (magnetic flux) can be reduced.

  The rice cooker of this invention can provide the rice cooker which reduced the magnetic field (magnetic flux) which leaks outside from a rice cooker, and made the main body compact.

1st invention is a rice cooker main body, the body which comprises the outline of the said main body, the pan detachably accommodated in the said main body, the heating coil which induction-heats the said pan, and the heating control part which controls heating coil operation | movement And an annular magnetic shielding material that is located on the outer side of the heating coil and reduces the release of magnetic flux generated from the heating coil to the outside of the main body, and the magnetic shielding material is a protective frame that is a pot storage portion of the main body The contact surface with the magnetic shielding material provided on the surface is formed by a cylindrical rib, and is supported by a protective frame that elastically deforms and fixes the magnetic shielding material, so that the magnetic shielding material does not contact the body, and the heating control The part is fixed to a protective frame and has a high-power element, and the magnetic flux generated from the high-power element by using the rice cooker in which the high-power element is disposed inside the magnetic shield and within the height width To prevent leakage from the main body It is possible. By reducing the magnetic flux generated from both the heating coil and the high power element with the magnetic shield, leakage of the magnetic flux outside the main body can be reduced. In addition, the magnetic shielding material vibrates at a high frequency due to the eddy current generated by the passage of magnetic flux. However, since the magnetic shielding material is not in contact with the body, the high frequency vibration of the magnetic shielding material is not transmitted to the body, so Can be prevented from leaking out of the main body. Furthermore, since the magnetic shielding material and the heating control unit are supported by the same member, the distance variation between the magnetic shielding material and the high power element of the heating control unit can be reduced, and the accuracy of the magnetic shielding performance can be increased.
(Embodiment 1)
1-5 shows the rice cooker in the 1st Embodiment of this invention.

  FIG. 5 shows the magnetic shield 22 by an phantom line A, and shows the magnetic shield 22 and the high power element 48 inside the magnetic shield 22 by omitting the ferrite 17 and the magnetic shield fixing portion 29. ing.

  In the figure, a pan 2 in which a removable outer surface of stainless steel is coated on the main body 1 of the rice cooker and the inner surface is coated with fluorine on aluminum is installed. The pan 2 is arranged at three locations equally, and the flange portion 11 of the pan 2 is supported by an upper frame cap 25 which is a member that supports the pan protruding from the main body 1. The outer shell of the main body 1 includes an upper frame 43 on the upper surface and a body 24 on the side lower surface. The body 24 is provided with an intake port 35 for taking in outside air by a cooling fan 49. The pan 2 storage part is composed of a protective frame 23 formed of a heat-resistant resin, a pan temperature detecting means 15 having a pressing force in the direction of the pan 2 by a spring for detecting the temperature of the pan 2 at the center of the bottom, and the protective frame 23. The heating coil 13 of the electromagnetic induction heating system which heats the pan 2 is provided in the lower surface of this, and the heating coil 13 is comprised by the inner heating coil 14a and the outer heating coil 14b which were divided | segmented and arrange | positioned inside and outside. A heating control unit 41 that controls the electromagnetic induction heating method is provided behind the main body 1. The heating control unit 41 includes a cooling fan 46 that takes outside air into the main body 1 at a position facing the intake port 35, and a cooling fan 46. Includes a heat-dissipating fin 47 formed of aluminum and a high-power element 48 such as a switching element or a rectifying element, and is supported by a heating control unit support base 39 extending from the protective frame 23 by screws 49. It is fixed. The cooling fan 46 is supported by a cooling fan support portion 34 extending in contact with the fins 47 and fixed by screws 50. Further, the cord reel 42 is arranged on the side of the heating control unit 42. Eight ferrites 17 are provided approximately equally on the outside of the inner heating coil 14a and the outer heating coil 14b to prevent magnetic flux from leaking outside the main body 1 and to promote induction heating to the pan 2. ing. Further, a magnetic shielding material 22 in which a belt-shaped aluminum plate is formed in an annular shape is disposed outside the heating coil 13 to improve the magnetic shielding performance. The upper surface of the magnetic shield 22 is higher than the upper end surface of the heating coil 13, and the lower surface of the magnetic shield 22 is lower than the lower end surface of the heating coil 13. Further, the positional relationship between the magnetic shielding material 22 and the high power element 48 is arranged such that the high power element 48 is included in the upper and lower end surfaces of the magnetic shielding material 22 by inclusion of the magnetic shielding material 22. Further, regarding the positional relationship between the magnetic shielding material 22 and the cooling fan 46, the magnetic shielding material 22 is arranged on the leeward side of the cooling fan 46. Here, the inner heating coil 14a and the outer heating coil 14b are arranged separately, but are driven simultaneously to heat the pan 2. Above the main body 1, a lid 3 that covers the upper surface of the pan 2 and includes an operation display unit 6 is axially engaged with a hinge portion 7 that is configured at the rear of the main body 1 and is installed so as to be freely opened and closed. The upper surface of the operation display unit 6 of the lid 3 is formed so as to be visible so that the display content can be visually recognized. The operation display unit 6 displays the function and the operation state and informs by a sound such as a buzzer, and operates and stops the rice cooker. It has the control part 5 which arrange | positions the starting means 4 comprised by the button which operates and controls rice cooking operation | movement. The lid 3 is provided with lid opening / closing detection means 18 composed of a magnet that operates according to the opening / closing state of the lid 3 and a reed switch that detects the magnet, so that the opening / closing state of the lid 3 can be detected. The hinge portion 7 is provided with a hinge spring 20 that urges the lid 3 in the opening direction, and the lid 3 is automatically opened by the hinge spring 20. A hook button 19 having a pressing force by a spring is provided in a direction opposite to the hinge portion 7 of the main body 1, and the lid 3 is held in the closed state by holding the hook 21 on the lid 3 side from above. Further, a heating plate 8 that heats the inside of the pan 2 and is detachable from the lid 3 is disposed on the surface of the lid 3 facing the pan 2, and a heating plate heating coil 26 of an electromagnetic induction heating system that heats the heating plate 8 is disposed inside the lid 3. And a heating plate temperature detecting means 16 having a pressing force to the heating plate 8 by a spring for detecting the temperature of the heating plate 8. The heating plate 8 includes a pot packing 28 that presses and seals the outer periphery to the flange portion 11 of the pot 2 and a heating plate support 27 that holds the pot packing 28. The heating plate 8 includes a steam hole 9 that communicates the inside of the pan 2 and the lid 3, and the lid 3 includes a steam cylinder 10 that communicates the outside air and the steam hole 9. A handle 12 used when carrying the rice cooker is provided on the side of the main body 1.

  Here, regarding the fixing and position of the magnetic shielding material 22, there are provided two magnetic shielding material fixing portions 29 for supporting and fixing the magnetic shielding material 22 to the protective frame 23. An upper defining portion 30 for defining the position, a lower defining portion 31 for defining the lower position of the magnetic shielding material 22, and two inner ribs 32 for supporting the magnetic shielding material 22 from the inside on the heating coil 13 side, The magnetic shielding material 22 is formed by outer ribs 33 provided at approximately the center of two inner ribs 32 that support the outer side opposite to the heating coil 13. The lower defining portion 31 includes a fitting fixing portion 36 having a claw shape that supports the magnetic shielding material 22 from below, and the magnetic shielding material 22 has a hole-shaped fitting corresponding to the claw-shaped portion of the fitting fixing portion 36. The magnetic shield 22 is provided with the mating and fixing portion receiver 40 so that it does not fall off from the protective frame 23. The contact surface of the inner rib 32 and the outer rib 33 with the magnetic shielding material 22 has a cylindrical surface shape 45 that is a curved surface, and the magnetic shielding material 22 is supported and fixed on the cylindrical surface. At this time, the magnetic shielding material 22 is supported by the two inner ribs 32 and the outer ribs 33. The straight portions of the magnetic shielding material 22 are sandwiched between the two inner ribs 32 and the outer ribs 33, and the magnetic shielding is performed by the outer ribs 33. The material 22 is deformed inward and supported. At this time, the magnetic shielding material 22 is supported and fixed only by the magnetic shielding material fixing portion 29 and is not in contact with the body 24, the heating control portion 41, and the like. Furthermore, a tapered surface is provided at the distal end of the magnetic-insulating material 22 insertion port of the inner rib 32 and the outer rib 33 so as to improve the attachment property of the magnetic-shielding material 22. The deformed portion 44 of the magnetic shielding material 22 by the outer rib 33 at this time is limited to the deformation within the elastic deformation region of the magnetic shielding material 22 which is an aluminum plate. Further, the magnetic-shielding material fixing portion 29 is provided with an erroneous mounting prevention projection 37 so that the magnetic-shielding material 22 can be attached only at a regular mounting position, and the magnetic-shielding material 22 is provided with an erroneous mounting prevention recess 38 at a position corresponding to the erroneous mounting prevention projection 37. I have.

  About the rice cooker comprised as mentioned above, the operation | movement and an effect | action are demonstrated below. Put the rice to be cooked and water corresponding to the amount of rice in two pots, and set the main body 1 in a predetermined state. When the operation start operation is performed by the activation means 4 provided in the operation display unit 6, the rice cooking process set in the control unit 5 in advance is performed. The rice cooking process is roughly divided into water immersion, cooking, and steaming processes. The temperature detection by the pan temperature detection means 15 and the heating plate temperature detection means 16, the internal heating coil 14a, the external heating coil 14b, and the heating plate heating coil 26 The rice is cooked in a predetermined rice cooking process by heating the pan 2 and the heating plate 8. In addition, when the rice is kept warm, the temperature of the rice in the pan 2 is maintained within a range from about 75 ° C., which is the temperature at which it is eaten, to about 55 ° C., which is a slightly lower temperature that reduces drying and deterioration of the rice.

Here, when the pan 2 is heated, a magnetic field is generated from the inner heating coil 14a and the outer heating coil 14b. The pan 2 side of the generated magnetic field heats the pan 2, but in a direction other than the pan 2. Since the magnetic field is emitted to the outside of the main body 1, the magnetic field is prevented from being released to the outside of the main body 1 by the ferrite 17 and further reduced by the magnetic shielding material 22 to prevent the magnetic field from leaking to the outside of the main body 1. .

  In order to prevent leakage of the magnetic field generated from the inner heating coil 14a and the outer heating coil 14b by the magnetic shielding material 22, the magnetic shielding material 22 is brought closer to the heating coil 13 to increase the efficiency of receiving the magnetic field or the shape of the magnetic shielding material 22 is enlarged ( Here, it is effective to expand the allowance of the magnetic shielding material from the upper and lower end surfaces of the heating coil 13 so as to receive a lot of magnetic fields, but if the magnetic shielding material 22 is too close to the heating coil 13, There is a possibility that the magnetic field to be heated will be absorbed and the pan 2 will be insufficiently heated, and there is a problem that if the shape is enlarged, the rice cooker body 1 will become large. However, the accuracy of the distance between the magnetic shield material 22 and the heating coil 13 is improved by defining the position of the magnetic shield material 22 by the inner rib 32 and the outer rib 33, and the magnetic shield material 22 is fixed by the upper defining portion 30 and the lower defining portion 31. By defining the position, the accuracy of the allowance from the upper and lower end surfaces of the heating coil 13 can be increased. By increasing the accuracy of the mounting position of the magnetic shield 22 with respect to the heating coil 13, it becomes possible to dispose the magnetic shield 22 to the vicinity of the heating coil 13 that does not affect the magnetic field of the pan 2, and the magnetic shield 22 is attached to the heating coil 13. By approaching, the efficiency of receiving the magnetic field of the magnetic shield 22 is increased, and the magnetic shield 22 can be downsized.

  Further, when the pan 2 is heated, a magnetic field is generated to generate high power in the high power element 48 and is released around the high power element 48. The high power element 48 is shielded by the inclusion of the magnetic shield material 22. By arranging so as to be within the upper and lower end surfaces of the material 22, the magnetic field is reduced by the magnetic shielding material 22, thereby preventing leakage of the magnetic field to the outside of the main body 1.

  The heating control unit 41 having the magnetic shielding material 22 and the high power element 48 is both attached to the protective frame, thereby reducing the placement error due to the dimensional variation and assembly variation of the magnetic shielding material 22 and the high power element 48. The magnetic shielding performance can be improved by increasing the positional accuracy of the magnetic shielding material 22 and the high power element 48.

  In the magnetic shielding by the magnetic shielding material 22, an eddy current is generated in the magnetic shielding material 22 so as to cancel the magnetic field passing through the magnetic shielding material 22. The magnetic shielding material 22 vibrates at a high frequency due to the generation of the eddy current. 22 is elastically deformed and fixed by the inner rib 32 and the outer rib 33 so that the magnetic shielding material 22 is in pressure contact with the inner rib 32 and the outer rib 33 and does not vibrate. Since it arrange | positions so that it may not contact 24, it can be set as the structure by which the abnormal noise by the vibration of the magnetic-shielding material 22 does not generate | occur | produce. Furthermore, the magnetic shield 22 generates heat when an eddy current is generated. By arranging the magnetic shield 22 on the leeward side of the cooling fan 46, the magnetic shield 22 is cooled by the cooling fan 46, resulting in a high temperature. Therefore, it is possible to maintain a stable magnetic shielding performance and to ensure safety by not becoming high temperature.

  Further, the contact surface between the inner rib 32 and the outer rib 33 that is in pressure contact with the magnetic shielding material 22 is a cylindrical surface shape 45, and the magnetic shielding material 22 is supported and fixed on the cylindrical surface so that the magnetic shielding material 22 is elastic. Even if the contact surface between the magnetic shield 22 and the inner rib 32 and the outer rib 33 changes due to deformation within the deformation, the contact surface with the magnetic shield 22 is always in contact with the cylindrical surface, and the contact state can be stabilized. . By stabilizing the contact state, even when the magnetic shielding material 22 vibrates at a high frequency, the pressure contact with the inner rib 32 and the outer rib 33 of the magnetic shielding material 22 is maintained. It can be set as the structure which does not generate | occur | produce a sound.

  Further, when fixing the magnetic shielding material 22, the lower regulation portion 31 is provided with the fitting fixing portion 36 that supports the magnetic shielding material 22 from below, so that the magnetic shielding material 22 does not require a fixing member or the like for fixing to the magnetic shielding material fixing portion 29. It can fix to the magnetic-shielding material fixing | fixed part 29. FIG.

  As described above, in the present embodiment, the magnetic shielding material fixing portion 29 is provided in the protective frame 23 provided with the heating coil 13, and the upper defining portion 30 that defines the upper position of the magnetic shielding material 23, and the magnetic shielding material 22 A lower defining portion 31 that defines the position in the downward direction, two inner ribs 32 that support the magnetic shielding material 22 from the inner side that is the heating coil 13 side, and an outer side that is the opposite side of the magnetic shielding material 22 from the heating coil 13. By forming the outer rib 33 provided at approximately the center of the two inner ribs 32 to be supported, the height of the magnetic shield 22 with respect to the heating coil 13 and the position in the radial direction are determined. 2 can be placed close to a position that does not affect the magnetic flux to be heated, and the magnetic field leakage of the magnetic shielding material 22 to the outside of the main body 1 is reduced by bringing the magnetic shielding material 22 closer to the heating coil 13. That effect is enhanced, can be miniaturized even in a magnetically shielded member 22 up and down in the height direction. The main body 1 can be made compact by reducing the size of the magnetic shielding material 22.

  Further, even in the magnetic field generated by the high power element 48, the high power element 48 is arranged so as to be contained in the upper and lower end surfaces of the magnetic shielding material 22 by the inclusion of the magnetic shielding material 22, so that the magnetic field is shielded by the magnetic shielding material 22. It is not released outward.

  Further, since the magnetic shielding material 22 is fixed by the magnetic shielding material fixing portion 29 and is not in contact with the body 24, vibration of the magnetic shielding material 22 is not transmitted to the body 24, so that vibration sound is generated due to contact between the magnetic shielding material 22 and the body 24. It is possible to cook rice quietly.

  Further, in fixing the magnetic shield 22, the lower defining portion 31 is provided with the fitting fixing portion 36 that supports the magnetic shield 22 from below, so that a fixing member for fixing the magnetic shield 22 to the magnetic shield fixing portion 29 is not required. . By not requiring a fixing member or the like, it is possible to reduce the size of the main body 1 by eliminating the space for mounting and arranging the fixing member.

  Further, since the magnetic shield 22 is elastically deformed and fixed by the inner rib 32 and the outer rib 33, the magnetic shield 22 is pressed against the inner rib 32 and the outer rib 33 even when the magnetic shield 22 vibrates at a high frequency. The contact does not vibrate, and no abnormal noise is generated by the vibration of the magnetic shielding material 22. Since no abnormal noise is generated due to vibration of the magnetic shielding material 22, both magnetic shielding and noise reduction can be achieved during the operation of the rice cooker.

  Furthermore, the contact surface of the inner rib 32 and the outer rib 33 with the magnetic shielding material 22 is formed into a cylindrical surface shape 45, and the magnetic shielding material 22 is supported and fixed on the cylindrical surface, whereby the inner rib 32 and the outer rib 33 of the magnetic shielding material 22 are fixed. Since the contact is always a line contact with the rounded surface of the inner rib 32 and the outer rib 33 regardless of the shape change due to elastic deformation of the magnetic shield 22, the fixation of the magnetic shield 22 can be stabilized.

  Furthermore, by fixing the heating control unit 41 including the magnetic shielding material 22 and the high power element 51 to the same protective frame 23, the positional accuracy of the magnetic shielding material 22 with respect to the high power element 48 is increased. Magnetic flux can be shielded with little variation, and the magnetic shield accuracy can be improved.

  In the present embodiment, eight ferrites 17 are arranged approximately equally. However, the number of ferrites 17 is not limited to 88, and the shape of the heating coil 13, the generation of magnetic flux due to power consumption, the shape of the main body 1 and the like. Increase or decrease by.

  In addition, although the magnetic-shielding material fixing portion 29 is provided in two places, the magnetic-shielding material fixing portion 29 is not limited to two locations, and the shape of the protective frame 23 and the arrangement of components such as the control unit 5 and the operation display unit 6, Moreover, it increases / decreases with the shape of the heating coil 13 and power consumption. Further, the magnetic shield material fixing portion 29 is formed by the upper defining portion 30, the lower defining portion 31, the outer rib 33, and the two inner ribs 32, but the magnetic shielding material fixing portion 29 includes the upper defining portion 30, the lower defining portion 31, and the like. The upper ribs 30 and the two inner ribs 32 are not limited to be collected in one place, but the upper defining portion 30 and the lower defining portion 31 are individually arranged, and the interval between the inner rib 32 and the outer rib 33 is set. Even if the arrangement is free, the same effect can be obtained as long as the configuration prevents the positioning and vibration of the magnetic shielding material 22.

  Further, although the outer rib 33 and the two inner ribs 32 are provided, the number of the inner rib 32 and the outer rib 33 is not limited to the one outer rib 33 and the two inner ribs. The same effect can be obtained by a configuration in which the position of the magnetic shielding material 22 is determined by the two outer ribs 33.

  In addition, the contact surface of the inner rib 32 and the outer rib 33 with the magnetic shielding material 22 is a cylindrical surface shape 45 and is a line contact by the cylinder surface. However, the contact surface is not limited to the line contact by the cylinder surface. This is the same in that the contact is always stable at a point on the spherical surface with respect to the contact of the magnetic shielding material 22, and the same effect can be obtained.

  Moreover, although the fitting fixing | fixed part receiver 40 was made into the hole shape, the fitting fixing | fixed part receiver 40 is not restricted to a hole shape, and there is no problem also as a structure fitted with the fitting fixing | fixed part 36 by the unevenness | corrugation which does not have a hole. The same effect can be obtained.

  As described above, the rice cooker according to the present invention disposes the magnetic field to the outside of the main body of both the heating coil and the high-power element by disposing the high-power element inside the height-shielding material and within the height width. Therefore, it is useful as a rice cooker for home use and business use.

The figure of the rice cooker in Embodiment 1 of this invention The main body inside back view of the rice cooker in Embodiment 1 of this invention The figure of the magnetic-shielding material fixing | fixed part of the rice cooker in Embodiment 1 of this invention The figure of the magnetic-shielding material fixing | fixed part of the rice cooker in Embodiment 1 of this invention The main body inside back view of the rice cooker in Embodiment 1 of this invention Figure of conventional rice cooker

DESCRIPTION OF SYMBOLS 1 Main body 2 Pan 13 Heating coil 14a Inner heating coil 14b Outer heating coil 22 Magnetic shielding material 23 Protective frame 24 Body 41 Heating control part 46 Cooling fan 48 High power element

Claims (1)

A rice cooker main body, a body constituting an outline of the main body, a pan detachably stored in the main body, a heating coil for induction heating the pan, a heating control unit for controlling a heating coil operation, and the heating coil And an annular magnetic shield that reduces the release of magnetic flux generated from the heating coil that is located on the outer side of the main body, and the magnetic shield is provided on a protective frame that is a pot housing portion of the main body. the contact surface between wood and formed from a rib of cylindrical surface shape, and the magnetically shielded member is elastically deformed supported by the protective frame for fixing, the arrangement in which the magnetic shielding material is not in contact with the body, said heating control unit includes the A rice cooker fixed to a protective frame and having a high-power element, wherein the high-power element is arranged inside the magnetic shielding material and within a height width.