JP2010091229A - Heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating cooker having a heat source capable of efficiently heating by reducing heat loss and shortening a time before cooking in heating cooking as well as of reducing energy consumption. <P>SOLUTION: A heating element unit used in the heating cooker comprises a heating element as the heat source. The heating element is formed to have a plate-like or belt-like shape by material containing carbon-based material. A wide part in a cross section of the heating element is arranged to be positioned orthogonally to a plate surface of a heat-resistant plate installed to make its plate surface face to a heated object, which uniformly heats the heat-resistant plate side. The heating cooking having small thermal capacity, an excellent rising characteristic, and little energy loss is performed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cooking device provided with a heating element unit as a heat source for cooking, and more particularly, to a cooking device provided with a heating element unit including carbon and including a heating element in a strip shape (plate shape). is there. Examples of the heating cooker according to the present invention include devices that require a heat source such as an electric stove, oven, toaster, microwave oven, griller, and composite products having these functions.

The cooking device includes a non-heated object placed at a position where the heating cooker can be heated, for example, a heat-resistant plate arranged at a position facing the cooking container, and the cooking plate with the heat-resistant plate positioned in the middle. A stove provided on the side facing the container, the heating element unit disposed in an internal space having the heat-resistant plate side formed in the stove as an opening, and the heating unit heated by the heating element unit The sensor includes a sensor for detecting the temperature of the internal space, and a control circuit for controlling the temperature of the internal space by a detection output detected by the sensor. Conventionally, a halogen heater formed of a tungsten material or a nichrome heater using a nichrome wire has been used as a heating element used in the heating element unit. (See Patent Document 1.)
JP-A-4-236016

  Halogen heaters used as a heat source for conventional cooking devices have the advantage of rapid start-up when power is supplied, but they have a large inrush current, and a large-capacity control circuit, that is, a complex circuit, is required to control the halogen heater on and off. In addition to the control structure, a high-capacity control circuit corresponding to the inrush current is required, which increases the size of the apparatus and causes a problem in cost. Furthermore, there is a problem that the fluorescent lamp flickers (flicker phenomenon) by controlling the heater.

  In addition, in the nichrome heater, almost no inrush current is generated. Therefore, the problem that the voltage drops when power is supplied to the heating element and the problem that the fluorescent lamp flickers (flicker phenomenon) are reduced. The problem of low heat capacity and the method of embedding the nichrome wire in a coil and taking it into the stove take heat to the stove side, and it takes time to rise, resulting in the time to reach the cooking temperature There were problems such as increased energy consumption due to the cost. Furthermore, since both the halogen heater and the nichrome heater are formed in a coil shape and have no directivity in the heat distribution, there is a problem that uniform heating cannot be obtained for the object to be heated.

  Specifically, the configuration and problems of a conventional cooking device will be described with reference to FIG. FIG. 7 is a cross-sectional view of the configuration of a conventional cooking device.

  As shown in FIG. 7, the conventional cooking device has a heat-resistant plate 11 provided as a part of the top wall of the cooking device and a lower surface side of the heat-resistant plate 11 in a vertical direction or a crossing direction with respect to the lower surface. A recess-shaped stove 12 having an inner space with the lower surface side being opened by having a side wall 12a along which the wall surface is disposed and a bottom wall 12b on which the wall surface is disposed so as to face the lower surface. At least. That is, the internal space is closed from the outer space of the stove 12 by being surrounded by the heat-resistant plate 11 covering the side wall 12a, the bottom wall 12b, and the opening. Two heating element units 20 each including a container 21 containing a heating element 22 formed in a coil shape are arranged in the inner space of the stove 12, and a heating cooker is disposed between the heating element units 20 arranged in parallel. A temperature sensor 13 for detecting the temperature of the internal space regarded as the temperature is disposed, and the temperature in the stove 12 is controlled.

  Since the heating element 22 made of a halogen heater or a nichrome heater of the heating element unit 20 used in the conventional cooking device does not have directivity, the distribution of heat generated as the heating element 22 alone becomes the temperature distribution 23. Since the space is closed by the side wall 12a and the bottom wall 12b of the stove 12 and the heat-resistant plate 11, a part of the heat generated in the stove direction, that is, the heat of the temperature distribution 23a is applied to the bottom wall 12b of the stove 12. Inefficient heat loss that is transmitted and not used for heating. Further, the heat that is not transferred to the bottom wall 12b of the stove 12 is thermally diffused in the stove 12, and finally the heat distribution for heating becomes a temperature distribution 24, and the heating state is concentrated near the upper and lower portions of the heating element unit 20. Become.

  Further, in the uniformity of temperature distribution inside the stove 12, the temperature of the adjacent space existing between the heating element units 20 arranged side by side or the side wall 12 a of the stove 12 is low, and the sensor 13 installed inside the stove 12 has a low temperature. Depending on the position, the followability of the temperature setting of the heating element unit 20 with respect to the temperature inside the stove 12 is slow and there is a problem with safety, and much heat is transferred to the bottom surface 12b of the stove 12, and the temperature rises outside the bottom surface 12b of the stove 12 Is a problem and in the worst case there is a risk of fire.

  An object of the present invention is to provide a heating cooker having a heat source that is small, excellent in safety, and highly reliable while reducing heat loss in cooking and shortening the time until cooking and heating efficiently. And

  In order to achieve the above object, a heating cooker according to a first aspect of the present invention includes a heat-resistant plate disposed so that a plate surface faces an object to be heated placed at a heatable position, and its heat resistance. A stove provided on the side facing the object to be heated with the plate positioned in the middle, and the heat-resistant plate side formed on the stove having an opening and surrounding the opening by the heat-resistant plate covering the opening An internal space closed from the space, the heating element unit disposed in the internal space so as to heat the object to be heated via a heat-resistant plate, and the internal space heated by the heating element unit A heating cooker provided with a sensor for detecting temperature, wherein the heating element as a heating source provided in the heating element unit is a plate-shaped or belt-shaped long planar body made of a material containing a carbon-based substance. Formed in the long planar body Wide portion of the elongated surface is configured such that the wide portion direction at least one location is arranged such that the vertical relative to the plate surface of the refractory plate. In the heating cooker according to the first aspect of the present invention configured as described above, the stove internal space is heated so that the temperature distribution in the internal space is uniform, and the heat of the increased internal space is the opening. Since the object to be heated is heated through the heat-resistant plate in a state where the temperature distribution is uniform from the whole, the start-up is quick and energy consumption can be reduced. Furthermore, by arranging the wide part of the long surface of the heating element to be perpendicular to the plate surface of the heat-resistant plate, the radiant heat from the heating element is reduced in the direction of the stove bottom wall. .

  In the heating cooker according to the second aspect of the present invention, a plurality of the heating element units are provided in the internal space according to the first aspect, and any one of the wide portions of the heating elements of the heating element unit and the Any one of the wide portions of the heat generating elements of the other heat generating units is arranged so that the width directions thereof face each other. The cooking device according to the second aspect of the present invention configured as described above has a more uniform temperature (heat) distribution inside the stove, that is, the temperature (heat) distribution in the stove. It becomes a cooking device.

  In the heating cooker according to the third aspect of the present invention, the heating element unit according to the first or second aspect includes the heating element, a power supply unit that supplies power to the heating element, the heating element, and the heating element. A container for storing a part of the power supply unit is provided, and the container is filled with an inert gas so that the end of the container is sealed. The cooking device according to the third aspect of the present invention configured as described above can raise the temperature of the heating element filled with the inert gas to a higher temperature, so that the cooking requiring a high temperature is required. Can be obtained.

  In the heating cooker according to the fourth aspect of the present invention, the heating element according to the third aspect has an interlayer structure formed of a material containing a carbon-based substance. The cooking device according to the fourth aspect of the present invention configured as described above uses a heating element with a small heat capacity, excellent thermal conductivity, quick start-up, and good followability to control. Therefore, high-performance and high-efficiency cooking is possible.

  In the heating cooker according to the fifth aspect of the present invention, the heating element according to the fourth aspect has a resistance change rate value obtained by dividing the resistance value at the time of balanced lighting by energization by the resistance value at the time of non-energization. It has a positive characteristic in which the heating element temperature is proportional to the resistance value. The cooker according to the fifth aspect of the present invention configured as described above can suppress a change in resistance due to the temperature of the heating element, and thus has excellent start-up while reducing the inrush current at the start of energization of the heating element. Cooking is possible.

  In the heating cooker according to the sixth aspect of the present invention, the heating element according to the fifth aspect is a thin film body having a thickness of 300 μm or less. In the heating cooker according to the sixth aspect of the present invention configured as described above, since the heating element has a small heat capacity and becomes a heat source that rises quickly, the heated object can be effectively heated, and energy consumption is reduced. Cooking is possible.

In the heating cooker according to the seventh aspect of the present invention, the heating element according to the fifth aspect is a light film having a density of 1.0 g / cm ³ or less. In the heating cooker according to the seventh aspect of the present invention configured as described above, since the heating element has a small heat capacity and becomes a heat source that rises quickly, the heated object can be effectively heated, and energy consumption is reduced. Cooking is possible.

  In the heating cooker according to the eighth aspect of the present invention, the heating element according to the fifth aspect is formed of a material having a thermal conductivity of 200 W / m · K or more. In the heating cooker according to the eighth aspect of the present invention configured as described above, since the heating element has excellent heat conduction, heating with excellent uniform temperature distribution and followability to control becomes possible.

In the heating cooker according to the ninth aspect of the present invention, the heating element according to the third aspect includes a carbon-based material and a resistance adjusting material, and is formed by firing. The cooker according to the ninth aspect of the present invention thus configured reduces the inrush current at the start of energization of the heating element by firing the heating element so as to stabilize the resistance change due to the heating element temperature. In addition, in consideration of safety such that the input does not increase at the time of abnormality, safe cooking is possible. In the cooking device according to the tenth aspect of the present invention, the heating element according to the ninth aspect is based on energization. The resistance change rate value obtained by dividing the resistance value at the time of balanced lighting by the resistance value at the time of non-energization is in the range of 0.8 to 1.2, and has a flat characteristic with a small heating element temperature and resistance value. is there. The heating cooker according to the tenth aspect of the present invention configured as described above bakes the heating element so as to stabilize the resistance change depending on the heating element temperature, thereby generating an inrush current at the start of energization of the heating element. It is reduced and the input is not increased at the time of abnormality, so that safety is taken into consideration, and safer cooking is possible. In the cooking device of the eleventh aspect of the present invention, the first to tenth aspects of the above In the heating element unit, a heat shield that blocks radiant heat radiated to the outer side of the end portion located in the longitudinal direction of the heating element is provided at the outer position of the end portion. The cooking device according to the eleventh aspect of the present invention configured as described above enables cooking by interrupting heating by the heating element unit on the stove side to prevent temperature rise on the stove side and promoting heating on the heat-resistant plate side.

  In the cooking device of the twelfth aspect of the present invention, a reflector is disposed at a position facing the heat-resistant plate via the heating elements of the first to eleventh aspects, and radiant heat from the heating elements is It is reflected by the reflector in the direction of the heat-resistant plate. The cooker according to the twelfth aspect of the present invention configured as described above can prevent heating of the stove side, particularly the bottom wall of the stove facing the heat shield plate via the heating element unit. The cooking which prevented the temperature rise of the side and accelerated | stimulated the heating of the heat-resistant board outer side is attained.

  In the heating cooker according to the thirteenth aspect of the present invention, a part of the power supply portion of the heating element unit according to the third to twelfth aspects passes through the stove and is located outside the stove. A plate-shaped light shielding material is arranged between a part of the power supply portion located outside the stove and the heat-resistant plate. In the heating cooker according to the twelfth aspect of the present invention configured as described above, light leaking from a part of the power supply portion of the heating element unit 10 passes through the heat-resistant plate 11 and moves outward from the heat-resistant plate 11. Due to the light shielding effect of the light shielding material 16 to prevent leakage, the user's anxiety is eliminated by the heat generating unit 10 being visible outside the stove.

  ADVANTAGE OF THE INVENTION According to this invention, the heating cooker which has a heat source with high efficiency which can heat to-be-heated objects, such as a cooking container, through a heat-resistant board in a state with uniform temperature distribution, and can be heated to high temperature. It becomes possible to do. In particular, according to the present invention, it is possible to provide a heating cooker that can start up quickly and perform cooking with reduced energy consumption.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a preferred embodiment of a heating cooker using a heating element unit according to the invention will be described with reference to the accompanying drawings.

The present inventors have developed a heating element unit that serves as a new heat source that eliminates the flicker phenomenon of the heating element unit of the heating element unit used in conventional cooking devices and the lack of directivity in heat distribution. I have been working on it. The heating element in the heating element unit as the new heating source is formed into a plate shape or a band shape from a material containing a carbon-based material, and the wide portion in the cross section of the heating element is arranged in a vertical direction with respect to the heat-resistant plate. As will be described later, the heat-resistant plate side is uniformly heated and has a small heat capacity and excellent start-up characteristics.
(Embodiment 1)
The heating cooker of Embodiment 1 which concerns on this invention is demonstrated using FIGS. 1-6.

  In the heating cooker according to the first embodiment, the heating element unit disposed in the stove generates heat when power is supplied from the power supply unit, and the stove becomes a high temperature state and is placed on the heat-resistant plate surface through the heat-resistant plate. A heated object (hereinafter referred to as a cooking container) is heated to perform cooking. Note that the space between the stove and the heat-resistant plate is almost closed, and the heat generated in the stove can be detected by a sensor disposed in the stove and controlled to a desired temperature so that cooking can be performed efficiently. Can do.

  FIG. 1 is a top view of the heating cooker according to Embodiment 1, and FIG. 2 is a cross-sectional view taken along the line BB in FIG.

  1 and 2, the heating cooker according to the first embodiment has a heat resistance arranged so that the object to be heated (not shown) faces the plate surface (in this example, the object to be heated is placed). Side wall 12a (inner wall surface along the vertical direction or crossing direction with respect to the heat-resistant plate 11) so as to surround the outer periphery of the plate 11 and the position facing the object to be heated via the heat-resistant plate 11, that is, the lower surface side of the heat-resistant plate 11 And a bottom wall 12b (a wall located on the bottom side having an inner wall surface in the opposite direction to the heat-resistant plate 11) to form a recessed internal space 12c having an opening on the heat-resistant plate 11 side. A stove 12 and a heating element 2 disposed at the center thereof are disposed at least in the stove 12, that is, in the internal space 12c, and a rod-like heating element disposed so that an end thereof penetrates the side surface 12a of the stove 12. Unit 10 and There.

  Further, two heating element units 10 are arranged side by side, and a part of the power supply portion provided at the end of the heating element unit 10 is disposed so as to be located outside the stove 12. The power supplied from an external power source is received. Further, light leaking from a part of the power supply portion of the heating element unit 10 passes between the heat-resistant plate 11 and the outside of the heat-resistant plate 11 between the part of the power supply portion and the heat-resistant plate 11. The light shielding material 16 is disposed so as not to leak, and the heat-shielding unit 16 can be seen outside the stove by the light shielding effect of the light shielding material 16 to remove the user's anxiety.

  Further, in the internal space 12 c of the stove 12, the opening of the internal space 12 c is closed by the heat resistant plate 11, and the heat of the internal space 12 c is transferred to the object to be heated via the heat resistant plate 11. In the closed state, even if heat is transferred to the outside through the gap between the heat-resistant plate 11 and the stove 12, there is no problem with the outside, or the heat in the internal space 12 c is transferred to the object to be heated via the heat-resistant plate 11. As long as the product is not hindered and does not hinder the product.

  A temperature sensor 13 for controlling the temperature of cooking is located between the heating element units 10 arranged in parallel, and is arranged to detect and control the temperature in the stove.

  In addition, in the heating cooking of Embodiment 1, although the heat generating body unit 10 demonstrates with the structure by the shape of a straight bar, it can also be comprised by the curved shape of U shape or a partial arc shape.

  Further, in order to prevent leakage of light emitted from the heating element unit 10 from the internal space 12c of the stove 12, a part of the power supply unit in the heating element unit 10 located on the outer side of the side wall 12a of the stove 12 and heat resistance Although it demonstrated by the structure which has arrange | positioned the plate-shaped light-shielding material 16 between the plates 11, the unnecessary light emitted from the heat generating unit 10 is not leaked from the internal space 12c of the stove 12 to the outside of the heating cooker. For example, any structure may be used as long as light leaking from a part of the power supply section passes through the heat-resistant plate 11 and does not leak the light to the outside of the heat-resistant plate 11, for example, the side wall 12a outside the stove 12 It is also possible to apply a heat-resistant light-shielding material to a part of the power supply unit in the heating element unit 10 located on the substrate, to perform vapor deposition, or to form a cap-shaped light-shielding material that covers a part of the power supply unit. It is a function. The light shielding material is preferably black that absorbs light.

  Moreover, in order to prevent the temperature rise of the stove 12 and to enable cooking that promotes heating of the object to be heated, for example, heating to the outside of the heat-resistant plate 11, the heat-resistant plate 11 is provided via the heating element 2. Opposite positions, for example, a lower space of the internal space 12c located between the heating element 2 and the bottom wall 12b (including a space from the inner space of the container to be described later of the heat generation unit 10 to the outer surface of the outer cylinder), or the internal space 12c A configuration in which at least a reflector (not shown) is disposed on the wall surface of the bottom wall 12b on the side to prevent heating of the bottom wall 12b can be employed.

  In the case where the radiant heat radiated from the heating element 2 is reflected to the outside of the heat-resistant plate 11 by the reflector, the range of reflection is set so as to uniformly heat the internal space, and the temperature distribution from the entire opening. If the object to be heated can be heated through the heat-resistant plate 11 in a uniform state, the stove rises more quickly and energy consumption can be reduced.

  Furthermore, the arrangement position of the reflector is not limited to the wall surface of at least the bottom wall 12b on the inner space 12c side described above, but on the surface of the object to be heated of the heat-resistant plate 11 facing the opening of the inner space 12c. The low temperature region where the temperature is lower than the vicinity of the heat generating unit 10 to be generated, in the first embodiment, the low temperature region located opposite to the heat generating unit 10 arranged in parallel, or the heat generating unit 10 and the side wall 12a (particularly, on the inner wall side of the side wall 12a away from the heating element unit 10), the low temperature region is arranged in parallel to reflect and heat the radiant heat radiated from the heating element unit 10. A second reflector is provided between the heating element units 10 or in a corner portion formed by the side wall 12a and the bottom wall 12b, and the low temperature region of the surface to be heated on the heat-resistant plate 11 is provided. By increasing the heat radiation amount, and that can reduce the energy consumption can be further uniformly heat the stove interior.

  As shown in FIGS. 1 and 2, the heating element unit 10 disposed in the internal space 12 c of the stove 12 has a plate-like or strip-like long planar body inside the container 1, that is, a solid or film sheet. The heating element 2 formed in the shape of the heating element 2 is built-in, and the wide part in the cross section of the heating element 2 positioned in the direction perpendicular to the longitudinal direction of the heating element unit 10, that is, the long surface of the elongated heating element unit 10 is provided. The heating element 2 is disposed so as to be positioned in the vertical direction with respect to the heat-resistant plate 11, and the heating element 2 is positioned at least in the internal space 12c.

  Further, the two heating elements 2 arranged side by side are positioned so that the wide portions thereof face the temperature sensor 13. Furthermore, both ends located in the longitudinal direction of the heating element unit 10 are arranged in a state of passing through holes provided in the side wall 12a, and external lead wires 7 to be described later lead out to the stove 12, that is, the external space of the side wall 12a. Therefore, electrical connection from an external supply power source is facilitated.

  In the first embodiment, the two heating elements 2 are described as being arranged in parallel. However, the heating elements 2 are not necessarily arranged in parallel. For example, the extended surface of the wide portion in the cross-sectional shape of the heating element is provided. A configuration in which the wide portions in the cross-sectional shape or the cross-sectional shape in which the wide portions in the cross-sectional shape of the heat generating body are curved in the longitudinal direction of the heat generating body and the extended surfaces of the wide portions are crossed and non-crossed are opposed to each other. There may be.

  In addition, although the heating cooker of Embodiment 1 demonstrates the structure provided with two heating element units 10, it is not limited to two in the heating cooker which concerns on this invention, It heats by one or more The structure to do may be sufficient.

  3 and 4 are a front view and a side view showing the heating element unit 10 in the cooking device of the first embodiment.

  Here, in the heating cooker according to the first embodiment, the heating element 2 will be described as being configured in the form of a film sheet having a strip shape, but the same configuration is applied to a solid shape having a plate shape.

  In addition, the structure of the heat generating unit 10 shown in FIG.3 and FIG.4 is an example in the heat source of the heating cooker which concerns on this invention, and this invention is not limited to this structure. The heat source in the heating cooker according to the present invention includes a film sheet-like heating element 2 to be described later, and other configurations in the heating element unit 10 are appropriately set according to product specifications and the like. The heating element unit 10 in the heating cooker according to the first embodiment includes a container 1, an elongated belt-shaped heating element 2, and a longitudinal direction of the heating element 2 in order to hold the heating element 2 at a predetermined position in the container 1. And an electric power supply unit 8 for supplying electric power to the heating element 2.

  The heating element 2 extends and is arranged along the longitudinal direction of the container 1. In the heating element unit 10, the container 1 is formed of a transparent quartz glass tube, and both ends of the quartz glass tube are welded in a flat plate shape to seal the container 1. Argon gas as an inert gas is sealed inside the container 1 that accommodates the heating element 2 and part of the power supply unit 8. The inert gas that can be enclosed in the container 1 is not limited to argon gas, but in addition to argon gas, nitrogen gas or argon gas and nitrogen gas, argon gas and xenon gas, argon gas and krypton gas, etc. It goes without saying that the same effect as that of the present invention can be obtained even if a mixed gas is used, and it can be appropriately selected according to the purpose. The reason why the inert gas is sealed inside the container 1 is to prevent oxidation of the heating element 2 that is a carbon-based substance inside the container 1 when used at a high temperature. As the material of the container 1, any material other than quartz glass can be used as long as it has heat resistance, insulation, and heat permeability. For example, glass such as soda lime glass, borosilicate glass, lead glass, etc. It selects suitably from materials, a ceramic material, etc. The sealing is a structure for preventing high-temperature oxidation of the heating element 2, but needless to say, it is not necessary for the heating material that forms the anti-oxidation coating on the surface of the heating element as seen in silicon carbide or the like.

  The power supply unit 8 provided at both ends of the heating element 2 includes a holder 3, a support ring 4, an internal lead wire portion 5, a molybdenum foil 6, and an external lead wire portion 7 attached to both ends of the heating element 2. It is out. An internal lead wire portion 5 is fixed to the holder 3, and the internal lead wire portion 5 is connected to both ends of the container 1 via molybdenum foils 6 embedded in sealed portions (welded portions) at both end portions of the container 1. Is electrically connected to an external lead wire portion 7 led out from the container.

  As shown in FIGS. 3 and 4, a support ring 4 that is a position restricting portion having a position restricting function is attached to the internal lead wire portion 5. The internal lead wire portion 5 is formed by forming a single wire, for example, a molybdenum wire in a coil shape.

  In addition, although the internal lead wire part 5 in Embodiment 1 demonstrates in the example formed with the molybdenum wire, it forms using the metal wire (round bar shape, flat plate shape) which used tungsten, nickel, stainless steel, etc. as a material. May be.

  Further, although the heat shield 9 is attached so as to be in contact with the support ring 4, when the heating element unit 10 is disposed in the internal space 12 c of the stove 12, the support ring 4 is attached to the heat shield 9. Is disposed within the depth width of the hole portion of the side wall 12a or in the internal space 12c in the vicinity of the hole portion. Therefore, the heat shield 9 has an effect of preventing the temperature of the power supply unit 8 from rising due to the heat generated from the heating element 2 and reducing the leakage of radiant heat from the inside of the stove 12. By blocking by the side wall 12a, it is further utilized. In addition, although the carbon plate with high heat dissipation and absorptivity was used as the material of the heat shield 9, the same applies to felt-like carbon, the material used for the lead wire having heat resistance, a plate of metal, etc. An effect can be obtained.

  As described above, in the heating element unit 10 of the heating cooker according to the first embodiment, the electric power configured by the holder 3, the support ring 4, the internal lead wire portion 5, the molybdenum foil 6, and the external lead wire portion 7. Supply parts 8 are provided on both sides of the heating element 2 to supply power to the heating element 2, and the heating element 2 is arranged at a predetermined position in the container.

  As a holding configuration of the heating element 2 and the holder 3, both ends of the wide surface of the heating element 2 are sandwiched between the ends of the heating element 2 by the holder 3. Further, both the end of the heating element 2 and the holder 3 are provided with through holes, and the through hole formed at the substantially center of the holder 3 and the through hole formed at the end of the heating element 2 are internal lead wires. It is penetrated by the end of the part 5. The end portion of the internal lead wire portion 5 is bent and formed in an L shape. The leading end of the internal lead wire portion 5 bent in an L shape projects through the through hole of the holder 3 with the heating element 2 interposed therebetween.

  In the configuration of the heating cooker, the protruding end portion 5a of the internal lead wire portion 5 protruding from the through hole of the holder 3 can be provided with a drop-off preventing means (drop-off preventing means). For example, the internal lead wire portion The protruding end portion 5a of 5 is made into a state of being deformed and crushed by plastic working, melting, or the like, and the protruding end portion 5a of the internal lead wire portion 5 has a shape larger than the diameter of the through hole of the holder 3. There are measures to prevent falling out.

  The support ring 4 of the heating element unit 10 is wound and fixed around the internal lead wire portion 5, and is formed in a coil shape. The support ring 4 is configured to be wound around the internal lead wire portion 5 for supplying power to the heating element 2, and the support ring 4 does not pass a current path from the external lead wire portion 7 to the heating element 2. That is, the support ring 4 is configured not to intervene in the current path in the internal lead wire portion 5. Thus, since the support ring 4 has a configuration in which no current flows to the heating element 2, it does not generate heat due to the current. The support ring 4 according to the first embodiment has a function of restricting the position of the heating element 2 and also functions as a heat dissipation function that radiates heat conducted from the heating element 2.

  The support ring 4 will be described using an example of a molybdenum wire. If the support ring 4 is a material that has rigidity capable of regulating the position of the heating element 2 and has excellent heat conduction (heat dissipation function) and easy processing, the support ring 4 4, for example, a metal material such as nickel, stainless steel, or tungsten can be used. However, the support ring 4 is not necessarily a necessary component depending on the configuration and specifications of the heating element unit, such as the length of the heating element 2 and the dimensional difference between the inner diameter of the container 1 and the heating element 2.

  In the heating element unit 10, since the material of the heating element 2 itself has elasticity and the shape pattern of the heating element 2 has elasticity, a mechanism for absorbing changes due to expansion and contraction in the heating element 2 is unnecessary. is there. In particular, since the heat generating element 2 used in Embodiment 1 has a small coefficient of thermal expansion, the heat generating element 2 disposed (stretched) in a state where tension is applied at the time of manufacture causes the heat generating element 2 and the heat generating element 2 to expand during heating. It can be absorbed by the elasticity of the shape pattern of the heating element 2.

  As a material used for the heat-resistant plate 11 used in the heating cooker according to the first embodiment of the present invention, a crystallized glass having a low coefficient of thermal expansion and excellent heat resistance is preferable. Further, the color of the crystallized glass is appropriately selected depending on the intended use, for example, white in the case of a heating cooker that requires a higher temperature than the object to be heated, and black if a high-class image is desired. be able to. The material of the heat-resistant plate 11 is not limited to crystallized glass, and any material that satisfies the specifications and applications of the cooking device can be selected as appropriate.

  The heating element 2 used in the heating element 10 of the heating cooker according to the first embodiment of the present invention is composed of a carbon-based material as a main component and a plurality of film sheet material layers laminated in the thickness direction with gaps therebetween. The film has excellent two-dimensional isotropic thermal conductivity, and is formed of a film sheet-like material having a thermal conductivity of 200 W / m · K or more. Therefore, the belt-like heating element 2 becomes a heat source that generates heat uniformly without temperature unevenness.

  Here, the two-dimensional isotropic heat conduction indicates that the heat conductivity in all directions on the plane set by the orthogonal X axis and Y axis is substantially the same. Therefore, in the present invention, the two-dimensional isotropic direction means, for example, one direction (X-axis direction) which is a carbon fiber direction in a heating element formed by arranging carbon fibers side by side in the same direction, or a carbon fiber as a cross. It does not indicate only the two directions (X-axis direction and Y-axis direction) that are the carbon fiber directions in the knitted heating element, but means that the film sheet-like heating element 2 has the same properties in the surface direction.

  The film sheet material that is a material of the heating element 2 has high heat resistance that is obtained by heat-treating a polymer film or a polymer film to which a filler has been added in an atmosphere at a high temperature, for example, 2400 ° C. or higher, and baking to graphitization. It is an oriented graphite film sheet, and has a thermal conductivity of 200 W / m · K or more in the plane direction. In particular, the thermal conductivity of the heating element 2 according to the present invention exhibits a characteristic of 600 to 950 W / m · K.

  The film sheet material, which is a material of the heating element 2 used in the present invention, has a laminated structure and has various surface shapes such as a flat surface, a concavo-convex surface or a corrugated surface in the surface direction. A space is formed between the opposing layers. In this laminated structure of film sheet materials, the image of the formation state of the voids formed between the layers is folded so as to overlap a plurality of times (for example, tens of times, hundreds of times) to make a pie dough, and the pie Similar to the cross-sectional shape of the pie obtained by baking the dough. That is, the heating element 2 has an interlayer structure in which a plurality of film bodies formed of a material containing a carbon-based material are laminated and a part of the lamination direction is fixed, and a film having flexibility in the thickness direction. It is a sheet material. Therefore, the film sheet material which is the material of the heating element 2 in the present invention is a material having excellent two-dimensional isotropic heat conduction having substantially the same heat conductivity in the plane direction as described above.

  Examples of the polymer film used as the film sheet material manufactured as described above include polyoxadiazole, polybenzothiazole, polybenzobisthiazole, polybenzoxazole, polybenzobisoxazole, polypyromellitimide (pyromellitimide) ), Polyphenylene isophthalamide (phenylene isophthalamide), polyphenylene benzimitazole (phenylene benzimitazole), polyphenylene benzobisimitazole (phenylene benzobisimitazole), polythiazole, polyparaphenylene vinylene And at least one kind of polymer film. In addition, as fillers added to the polymer film, phosphate ester, calcium phosphate, polyester, epoxy, stearic acid, trimellitic acid, metal oxide, organotin, lead, azo, Examples thereof include nitroso and sulfonyl hydrazide compounds. More specifically, examples of the phosphoric ester compound include tricresyl phosphate, phosphoric acid (trisisopropylphenyl), tributyl phosphate, triethyl phosphate, trisdichloropropyl phosphate, trisbutoxyethyl phosphate, and the like. be able to. Examples of calcium phosphate compounds include calcium dihydrogen phosphate, calcium phosphate hydrogen, tricalcium phosphate, and the like. Examples of polyester compounds include polymers obtained by reaction of adipic acid, azelaic acid, sebacic acid, phthalic acid and the like with glycols and glycerins. Examples of stearic acid compounds include dioctyl sebacate, dibutyl sebacate, and acetyl tributyl citrate. Examples of the metal oxide compound include calcium oxide, magnesium oxide, lead oxide and the like. Examples of trimellitic acid compounds include dibutyl fumarate and diethyl phthalate. Examples of the lead compound include lead stearate and lead silicate. Examples of the azo compound include azodicarbonamide and azobisisobutyronitrile. Examples of the nitroso compound include nitrosopentamethylenetetramine. Examples of the sulfonyl hydrazide compound include p-toluenesulfonyl hydrazide.

  The film sheet material is laminated, processed in an inert gas at 2400 ° C. or higher, and controlled by adjusting the pressure of the gas processing atmosphere generated in the process of graphitization to produce a film sheet heating element . Furthermore, if necessary, the film sheet-shaped heating element produced as described above is subjected to a rolling treatment to obtain a higher-quality film sheet-shaped heating element. The film sheet-like heating element manufactured in this way is used as the heating element 2 in the heating element unit of the present invention.

  In addition, the range of 0.2-20.0 weight% is suitable for the addition amount of the said filler, More preferably, it is the range of 1.0-10.0 weight%. The optimum addition amount differs depending on the thickness of the polymer. When the polymer thickness is thin, the addition amount is preferably large, and when it is thick, the addition amount may be small. The role of the filler is to make the film after heat treatment into a uniform foamed state. That is, the added filler generates a gas during heating, and the cavity after the generation of the gas becomes a passage to help the gentle passage of the decomposition gas from the inside of the film. The filler thus helps to create a uniform foamed state.

  The film sheet material manufactured as described above is processed into a desired shape by, for example, a Thomson or Pinnacle punch, a sharp blade such as a rotary die cutter, or laser processing.

  As shown in FIG. 3, a plurality of slits 2 a are extended in the direction perpendicular to the longitudinal direction of the heating element 2 in the heating part of the heating element 2 in the first embodiment. The plurality of slits 2a formed in the heat generating part regulates the direction of current flow in the heat generating part and adjusts the resistance value. As the slit shape formed in the heat generating portion, there are a groove penetrating according to a product specification and application in which the heat generating unit 10 is used, a bottomed recessed groove, and the like. Further, in the concave groove, the resistance value of the heat generating portion can be adjusted by changing the depth in the thickness direction.

  In addition, by forming a slit in the heating element 2 in the first embodiment, the heating element 2 has a large elasticity due to the elasticity of the slit shape in addition to the elasticity of the heating element itself. Become.

  Hereinafter, the features of the configuration of the heating element 2 of the heating element unit 10 used as a heat source in the heating cooker according to the first embodiment of the present invention will be described with reference to FIG. Note that the light shielding material 16 described in FIGS. 1 and 2 is not illustrated on FIG. 5 for convenience of description.

  5 is a cross-sectional view taken along the line AA of FIG. 1, which is a top view of the heating cooker according to the first embodiment, and shows a temperature distribution in the stove 12 (internal space 12c) of the heating cooker according to the present invention. Since the heating element 2 has directivity, the heat distribution 14 generated as a single heating element 2 spreads mirror-symmetrically about the long surface of the heating element, and the spread of heat distribution is It spreads with the direction perpendicular to the wide part of the heating element (the plate surface direction of the heat-resistant plate) as the central axis. However, since the space is closed by the side wall 12 a and the bottom wall 12 b of the stove 12 and the heat-resistant plate 11, a part of the heat generated in the direction of the stove 12, that is, the heat of the temperature distribution 14 a, The heat transferred to 12b becomes an inefficient heat loss that is not used for heating, but the heat not transferred to the bottom wall 12b of the stove 12 is diffused in the stove 12 to a uniform temperature state. As a result, the heat distribution for heating finally becomes the temperature distribution 15, and the wide surface of the heat-resistant plate 11 is uniformly heated, and the object to be heated is evenly heated.

  The heating element unit 10 used in the heating cooker according to the present invention has a heating element 2 as a heating source, and the heating element 2 is formed in a plate shape or a band shape from a material containing a carbon-based substance. The amount of heat radiation from the wide part in the cross section of the heating element 2 is much larger than the amount of heat radiation from the narrow part in the cross section of the heating element 2 and has high directivity in the wide part direction in the cross section of the heating element 2. is doing.

In the heating device of the first embodiment, as described above, the wide portion in the cross section of the heat generating element 2 is arranged vertically in the plate surface direction of the heat-resistant plate 11, and the radiant heat from the heat generating element 2 is the plate surface of the heat-resistant plate 11. Since the radiation is mainly radiated in the direction, inefficient heat loss to the bottom wall 12b of the stove 12 as compared with the non-directional halogen heater or nichrome heater described using the configuration of the conventional cooking device of FIG. The configuration is such that the radiation is reduced, and the heat distribution radiated from the heating element 2 alone becomes the temperature distribution 14. However, since it is a space closed by the heat-resistant plate 11 and the stove 12, the heat 14 a emitted in the stove direction is partially transmitted to the bottom wall 12 b of the stove 12, but most of it is thermally diffused in the stove 12. Finally, the temperature distribution 15 is obtained.
That is, as is clear from the temperature distribution of the conventional cooking device described above with reference to FIG. 7, a uniform temperature distribution 15 is possible on the heat-resistant plate 11 and the temperature inside the stove 12 is also uniform. There is no temperature difference detected from the inside of the stove 12 and the sensor 13 and the cooking device is excellent in followability and safety. Furthermore, since the inefficient heat loss radiated from the heating element 2 to the bottom wall 12b of the stove 12 is reduced, the cooking device is highly efficient and excellent in safety.

  Hereinafter, the characteristics of the heating element 2 of the heating element unit 10 used as a heat source in the heating cooker according to the first embodiment of the present invention, the plate-shaped heating element containing carbon, and the features of the conventional halogen heater will be described.

  The inventors have a film-sheet-shaped heating element (hereinafter referred to as a film-sheet-like heater) that is an example of the heating element 2 of the heating element unit 10 used in the heating cooker according to the present invention, and the heating element. 2 is a heating element (hereinafter abbreviated as a carbon heater) using a long and thin plate-like heating element including a resistance adjusting substance as a main component and including a resistance adjusting substance, and halogen as a conventional technique. Comparison of temperature characteristics showing the relationship between temperature [° C] and resistance [Ω] at the time of balanced lighting by using a heater with specifications of 100V and 600W for a heating element using a lamp (hereinafter abbreviated as a halogen heater). The experiment was conducted.

  FIG. 6 is a temperature characteristic diagram showing the relationship between the temperature [° C.] and the resistance [Ω] in the various heating elements described above. In FIG. 6, the solid line X is the temperature characteristic of the film sheet heater used in the heating cooker according to the first embodiment of the present invention. The broken line Y is the temperature characteristic of the carbon heater, and the alternate long and short dash line Z is the temperature characteristic of the conventional halogen heater shown in FIG.

  As shown in FIG. 6, the film sheet heater, which is the heating element 2 of the heating element unit 10 used in the heating cooker according to the first embodiment of the present invention, has resistance as the temperature of the heating element during lighting increases. Has an increasing positive characteristic. According to the experiment, for example, when the temperature of the film sheet heater is 20 ° C. (when not energized), the resistance value is 9.2Ω, and when the temperature during balanced lighting is 1120 ° C., the resistance value is 16.7Ω. there were. Therefore, the change rate (resistance change rate) of the resistance value when the film sheet heater is not energized and when the film is lighted is 1.81. Note that the balanced lighting here refers to a time when a voltage (for example, 100 V) is applied to the heating element, electric power is supplied, current flows through the heating element, and the heating temperature of the heating element becomes constant. The resistance change rate is a value obtained by dividing the resistance value at the time of balanced lighting by energization of the heating element by the resistance value at the time of non-energization.

  On the other hand, the temperature characteristic of the carbon heater indicated by the broken line Y shows a substantially constant resistance value even when the temperature during balanced lighting changes. According to the experiments by the inventors, when the temperature of the carbon heater is 20 ° C. (when not energized), the resistance value is 15.9Ω, and when the temperature during balanced lighting is 1030 ° C., the resistance value is 16.7Ω. Met. Therefore, the rate of change in resistance when the carbon heater is not energized and when the carbon tube is balanced is 1.05. In the case of the halogen heater indicated by the alternate long and short dash line Z, the resistance value is 1.8Ω when the temperature is 20 ° C. (when not energized), and the resistance value is 16.7Ω when the temperature during balanced lighting is 1830 ° C. Met. Therefore, the rate of change in resistance when the halogen heater is not energized and when it is balanced is 9.28.

  In addition, using the film sheet heater used in the cooking device for heating according to the first embodiment, when the temperature change at the time of balanced lighting is changed and the resistance change rate at the time of balanced lighting is confirmed, balanced lighting is performed. Even when power was supplied so that the temperature at 500 ° C. was the rising characteristic indicated by the solid line X in FIG. 4, the resistance value at 500 ° C. was 11.0Ω. Therefore, the resistance change rate between the unlit state and the balanced lighting when the temperature at the balanced lighting of the film sheet heater is 500 ° C. is 1.2 (= 11.0 / 9.2).

  In addition, when power is supplied using the film sheet heater used in the heating cooker of Embodiment 1 so that the temperature at the time of balanced lighting is 2000 ° C., two points following the solid line X in FIG. The rising characteristic is indicated by a broken line, and the resistance value at 2000 ° C. was 32.2Ω. Therefore, the resistance change rate between the unlit state and the balanced lighting when the temperature at the balanced lighting of the film sheet heater was 200 ° C. was 3.5 (= 32.2 / 9.2).

  As described above, the film sheet heater of the heating element unit 10 used in the heating cooker of Embodiment 1 has a positive characteristic that the resistance increases as the temperature setting at the time of balanced lighting increases. As is clear from the above results, when the temperature setting at the time of balanced lighting is 500 ° C., the resistance value at the time of balanced lighting is 11.0Ω, and the resistance change rate is 1.2. When the temperature setting for balanced lighting is 2000 ° C, the resistance value for balanced lighting is 32.2Ω, the resistance change rate is 3.5, and the temperature and resistance value for balanced lighting are approximately proportional. Show.

  Further, the heating element 2 of the heating element unit 10 used in the heating cooker of Embodiment 1 has a resistance change rate of 1.81 obtained by dividing the resistance value at the time of balanced lighting by rated energization by the resistance value when not energizing. Met. As described above, the heating element 2 of the heating element unit 10 used in the heating cooker according to the present invention has a certain resistance (9.2Ω) even when not energized. The rate of change in resistance is 1.81.

  The film sheet heater of the heating element unit 10 according to the present invention generates heat at a desired temperature with high accuracy by setting the electric power or the heater temperature so that the resistance change rate is in the range of 1.2 to 3.5. In addition, when the heating element unit 10 is turned on, there is an effect of speeding up the start-up at the time of heat generation without generating a large inrush current. That is, when the rate of change in resistance value when not energized and when the balance is lit is less than 1.2, the inrush current is small and there is no problem, but there is a problem that the rise is slow and the temperature is low. Can not be satisfied. Also, if the rate of change in resistance value when not energized and balanced lighting exceeds 3.5, a large inrush current will occur, so it is necessary to set a large margin for each component in order to ensure reliability, There is a problem in that the capacity of the component increases, resulting in an increase in manufacturing cost and an increase in size of the apparatus. Therefore, in the case of the film sheet heater of the heating element unit 10 according to the present invention, it is desirable that the rate of change of the resistance value between non-energized and balanced lighting is between 1.2 and 3.5.

  On the other hand, when a carbon heater, which is another example of the heating element unit 10 according to the present invention, is used as a heat source, the resistance value is substantially constant regardless of the temperature at the time of balanced lighting. It does not occur and a substantially constant current flows. Therefore, when a carbon heater is used as a heat source, there is a problem that the rate of rise (rise) of the heat generation temperature is slower than when a film sheet heater is used, and it takes time to reach a predetermined temperature. As a cooking device, a carbon heater with the characteristics of no inrush current in the specifications of high input and high wattage can take measures such as contact welding and inability to control and has excellent safety. Moreover, the resistance change rate of the carbon heater material can be adjusted, and by making the range from 0.8 to 1.2, it is possible to improve the speed at the time of start-up and the inrush.

  On the other hand, when a carbon heater containing a carbon-based substance and a resistance adjusting substance and used as a heat source is used as a heat source, the resistance value is substantially constant regardless of the temperature at the time of equilibrium lighting. No current is generated and a substantially constant current flows. Therefore, when the carbon heater is used as a heat source, the rate of rise (rise) of the heat generation temperature is slightly slower than when the film sheet-like heat generating element 2 is used, and it takes time to reach a predetermined temperature. However, carbon heaters with high input and high watt specifications that do not have inrush current as a cooking device can take measures such as contact welding and control failure, and have excellent safety. Moreover, the resistance change rate of the carbon heater material can be adjusted, and by making the range from 0.8 to 1.2, it is possible to improve the speed at the time of start-up and the inrush.

  The above-mentioned carbon heater uses a plate-like heating element formed of a mixture of crystallized carbon such as graphite, a resistance adjusting substance, and amorphous carbon. In the carbon heater, the infrared emissivity of the carbon-based substance is high. Since it is as high as 78 to 84%, by using a carbon-based material as a heating element, the infrared emissivity from the carbon heater is increased, and a highly efficient heat source can be constructed. However, the heating element used in the carbon heater is a plate-like heating element having a thickness (for example, several mm), and has a somewhat large heat capacity. It is possible to adjust the resistance change in this material configuration and manufacturing process.

  The specific resistance value of the heating element 2 of the heating element unit 10 is 250 μΩ · cm, the specific resistance value of carbon of the carbon heater is 3000 to 50000 μΩ · cm, and the specific resistance value of tungsten of the halogen heater is 5.6 μΩ · cm. It is. As described above, since the specific resistance value of carbon is very high compared to other heater materials, it is possible to design with less current change and with less inrush current during power supply. In addition, the specific resistance value of the heating element 2 is smaller than the specific resistance value of carbon, but is larger than the specific resistance value of tungsten. Therefore, the heating element 10 is easier to design than the heating element of tungsten.

Further, the density of the heating element 2 of the heating element unit 10 is 0.5 to 1.0 g / m ³ (depending on the thickness), the carbon density of the carbon heater is 1.5 g / m ³ , The density of tungsten is 19.3 g / m ³ . Thus, since the density of the heating element 2 and the carbon heater are lighter than the material of the halogen heater, and the heating element 2 is a strip-shaped thin film body, the heat capacity is extremely small compared to other heaters, and the rise is high. I can understand that it will be faster.

  As described above, the film sheet heater used in the heating cooker according to Embodiment 1 has excellent characteristics that it is light and thin, has a small heat capacity, and quickly rises up to the balanced lighting by energization. For this reason, in the heating cooker of Embodiment 1, since the heating element unit having a heating element having excellent responsiveness and heating with high efficiency is used, the heating of the upper surface region of the heat-resistant plate is accelerated and energy saving is achieved. As well as a quick start. Further, in the heating cooker according to the first embodiment, when a carbon heater including a carbon-based substance and a resistance adjusting substance is used instead of a film sheet heater and formed by baking as a heat source, It has an excellent characteristic that the resistance value is substantially constant regardless of the temperature. For this reason, a large inrush current does not occur at the time of lighting in the initial stage of heating, and the problems of voltage drop and flicker that flickers the fluorescent lamp are solved.

  That is, depending on the specification, application, and purpose of the heating cooker, the heating element material of the heating element unit 10 is either a film sheet heater or a carbon heater that includes a carbon-based substance and a resistance adjusting substance and is formed by firing. Can be appropriately selected.

  The present invention provides a high-efficiency cooking device capable of reducing heat loss and heating to a high temperature with a heating element configuration that uniformly heats a cooking container, a cooked food, and the like that are on the surface of a heat-resistant plate. And is useful in the field of cookers.

The top view in the heating cooker of Embodiment 1 which concerns on this invention BB sectional drawing in the heating cooker of Embodiment 1. FIG. Heater unit front view in heating cooker of embodiment 1 Side view of heating element unit in heating cooker according to embodiment 1 Heat distribution diagram in AA sectional view in heating cooker of embodiment 1 Temperature characteristic diagram showing the relationship between the temperature [° C.] and the resistance [Ω] in the heating element 2 of the heating element unit 10 in the first embodiment. Heat distribution diagram in the AA cross section in the case of the conventional example

Explanation of symbols

1, 21 Container 2, 22 Heating element 2a Slit 3 Holder 4 Support ring (position regulating part)
DESCRIPTION OF SYMBOLS 5 Internal lead wire part 5a Projection end part 6 Molybdenum foil 7 External lead wire part 8 Electric power supply part 9 Heat shield 10, 20 Heating element unit 11 Heat-resistant plate 12 Stove 12a Side wall 12b Bottom wall 12c Internal space 13 Temperature sensor 14, 14a , 15, 23, 23a, 24 Temperature distribution 16 Shading material

Claims (13)

  A heat-resistant plate arranged so that the plate surface faces the object to be heated placed in a heatable position, and a stove provided on the side facing the object to be heated with the heat-resistant plate positioned in the middle; Heating the object to be heated via the heat-resistant plate and an internal space closed from the space surrounding the stove by the heat-resistant plate covering the opening with the heat-resistant plate side formed in the stove A heating cooker in which the heating element unit disposed in the internal space and a sensor for detecting the temperature of the internal space heated by the heating element unit are disposed. The heating element provided as a heating source is formed into a plate-shaped or band-shaped long planar body using a material containing a carbon-based substance, and the wide portion of the long surface of the long planar body is at least one of Wide part direction in the place There cooker, characterized in that it is arranged so as to be vertical to the plate surface of the refractory plate.   A plurality of the heating element units are provided in the internal space, and any one of the wide portions of the heating elements of the heating element unit and any one of the wide portions of the heating elements of the other heating element units are mutually connected. The cooking device according to claim 1, wherein the cooking devices are arranged so that the width directions face each other.   The heating element unit includes a heating element, a power supply unit that supplies power to the heating element, and a container that houses the heating element and a part of the power supply unit, and an inert gas inside the container. The cooking device according to claim 1, wherein the container is sealed and the end of the container is sealed.   The cooking device according to claim 3, wherein the heating element has an interlayer structure formed of a material containing a carbon-based substance.   The heating element has a resistance change rate value obtained by dividing the resistance value at the time of balanced lighting by energization by the resistance value at the time of non-energization within a range of 1.2 to 3.5, and the heating element temperature and resistance value are The cooking device according to claim 4, wherein the cooking device has a proportional positive characteristic.   The cooking device according to claim 5, wherein the heating element is a thin film body having a thickness of 300 μm or less. The cooking device according to claim 5, wherein the heating element is a light film having a density of 1.0 g / cm ³ or less.   The cooking device according to claim 5, wherein the heating element is made of a material having a thermal conductivity of 200 W / m · K or more. The cooking device according to claim 3, wherein the heating element includes a carbon-based material and a resistance adjusting material, and is formed by firing.   The heating element has a resistance change rate value obtained by dividing the resistance value at the time of balanced lighting by energization by the resistance value at the time of non-energization in a range of 0.8 to 1.2, and the heating element temperature and resistance value are The cooking device according to claim 9, wherein the cooking device has a small flat characteristic.   The heat generating unit is characterized in that a heat shield for blocking radiant heat radiated to the outer side of the end located in the longitudinal direction of the heat generating element is provided at the outer position of the end. The heating cooker as described in any one of Claims 1 thru | or 10.   12. A reflector is disposed at a position facing the heat-resistant plate through the heating element, and radiant heat from the heating element is reflected toward the heat-resistant plate by the reflector. The heating cooker as described in any one of. A part of the power supply part of the heating element unit is disposed so as to pass through the stove and be located outside the stove, and a part of the power supply part located outside the stove The cooking device according to any one of claims 3 to 12, wherein a plate-shaped light shielding material is disposed between the heat-resistant plate and the heat-resistant plate.

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