EP2645001A1 - Dispositif de chauffage à micro-ondes - Google Patents

Dispositif de chauffage à micro-ondes Download PDF

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Publication number
EP2645001A1
EP2645001A1 EP11843277.2A EP11843277A EP2645001A1 EP 2645001 A1 EP2645001 A1 EP 2645001A1 EP 11843277 A EP11843277 A EP 11843277A EP 2645001 A1 EP2645001 A1 EP 2645001A1
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EP
European Patent Office
Prior art keywords
gridiron
heating chamber
outer frame
heating
heating device
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP11843277.2A
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German (de)
English (en)
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EP2645001A4 (fr
EP2645001B1 (fr
Inventor
Masaki Shibuya
Hiroshi Kawai
Ryuta Kondo
Makoto Nishimura
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Panasonic Corp
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Panasonic Corp
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Publication date
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Publication of EP2645001A1 publication Critical patent/EP2645001A1/fr
Publication of EP2645001A4 publication Critical patent/EP2645001A4/fr
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Publication of EP2645001B1 publication Critical patent/EP2645001B1/fr
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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/6408—Supports or covers specially adapted for use in microwave heating apparatus
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
    • F24C15/00—Details
    • F24C15/16—Shelves, racks or trays inside ovens; Supports therefor

Definitions

  • the present invention relates to microwave heating devices for performing microwave heating.
  • a heating cooker described in the aforementioned Patent Literature 1 is structured, such that a rotational plate made of a glass is placed on a rotational grid in a microwave heating mode, while a rectangular plate made of a metal is placed on the rotational grid in an oven heating mode, in order to place objects to be heated at desired positions within the heating chamber, for enabling heating cooking thereon.
  • a circular grid unit 100 with fine meshes as illustrated in Fig. 12 is provided within the heating chamber.
  • standing waves are induced within the heating chamber of the heating cooker, due to microwaves from an antenna and waves reflected by the wall surfaces. Therefore, a grid-shaped member 101 constituting the metal grid unit 100 is placed, in areas in the vicinities of antinodes of standing waves induced within the heating chamber in the microwave heating mode (areas which are subjected to larger electric fields).
  • larger electric currents flow through the grid-shaped member 101 in the grid unit 100, which causes the grid unit 100 to generate heat, thereby inducing energy losses. This has caused degradations of the heating efficiency of the conventional heating cooker.
  • Fig. 13 is a plan view illustrating the structure of an ordinary gridiron 102 provided within the heating chamber in a conventional heating cooker.
  • the gridiron 102 is structured to include an outer frame 103 which conforms to the shape of the heating chamber, and a plurality of rod-shaped members 104 placed at smaller intervals with respect to the outer frame 103.
  • the rod-shaped members 104 constituting the metal gridiron 102 are placed in areas in the vicinities of antinodes of standing waves which are induced within the heating chamber in a microwave heating mode (areas designated as "MA" as examples in Fig. 13 ).
  • areas designated as "MA" areas in Fig. 13 .
  • the microwave heating mode larger electric currents flow through the rod-shaped members 104 in the gridiron 102, which has induced the problem of abnormal heat generation from the gridiron 102.
  • the conventional heating cooker has had the problem of occurrence of significant energy losses and, therefore, degradations of the heating efficiency of the heating cooker, in cases of using the gridiron in the microwave heating mode.
  • the present invention is made to overcome the aforementioned problems in conventional microwave heating devices and aims at providing a microwave heating device with higher efficiency which can suppress abnormal heat generation from grid members and the like which are placed within the heating chamber, thereby reducing energy losses.
  • a microwave heating device includes:
  • the present invention having the aforementioned structure, it is possible to provide a microwave heating device with higher efficiency which prevents larger electric currents from flowing through the bridge members, thereby suppressing abnormal heat generation from the gridiron and reducing energy losses, in a microwave heating mode.
  • the microwave heating device can provide a heating apparatus with higher efficiency which can suppress abnormal heat generation from the grid member and the like which are placed within the heating chamber, thereby inducing less energy losses.
  • a microwave heating device including:
  • the outer frame and at least one of the bridge members are provided in the vicinities of nodes of the standing wave.
  • the second invention having the aforementioned structure, it is possible to inhibit electric currents from flowing through the outer frame and/or the bridge members which are provided in the vicinities of nodes, which prevents abnormal heat generation from the gridiron. This provides a microwave heating device with higher efficiency which induces less energy losses.
  • the bridge members are provided at positions spaced apart from an inner wall of the heating chamber, by a length equal to or more than 3/8 the wavelength of the standing wave.
  • a rail portion which enables the gridiron to be inserted in the inside of the heating chamber, and there is provided an insulating structure between the rail portion and the gridiron.
  • the gridiron is structured such that a plurality of the bridge members are secured to the outer frame in parallel with each other, the bridge members adjacent to each other are formed from a single rod-shaped member, and end portions of the rod-shaped members are not protruded from the outer frame toward a side-surface wall of the heating chamber.
  • the rod-shaped members are adapted such that their end portions are not protruded within the heating chamber, which can suppress concentration of electric fields in the gridiron, thereby preventing abnormal heat generation.
  • the microwave heating device forms a heating apparatus with higher efficiency which induces less energy losses.
  • the bridge members are formed from rod-shaped members having an annular shape.
  • the bridge members have no end portion, which prevents abnormal heat generation from the gridiron.
  • the microwave heating device forms a heating apparatus with higher efficiency which induces less energy losses.
  • the annular shape of the bridge members forms an elongated track shape.
  • the seventh invention having the aforementioned structure, there remain straight-line portions as in such a track shape (elongated annular shape), which can reduce the distance over which the bridge members form bridges in the outer frame as much as possible, thereby reducing the fabrication costs. This can suppress flexures thereof when objects to be heated are placed thereon. This can provide a microwave heating device with higher efficiency which induces less energy losses.
  • the bridge members are formed to have a turned-back meandering shape.
  • the eighth invention having the aforementioned structure, it is possible to reduce the welded portions, which can suppress heat generation due to concentrations of electric fields at the welded portions. This can provide a microwave heating device with higher efficiency which induces less energy losses.
  • the bridge members are secured to the outer frame, such that the bridge members are in contact with an inner periphery of the outer frame.
  • the ninth invention having the aforementioned structure, it is possible to eliminate gaps formed by the intersection of the outer frame and the bridge members, which can suppress heat generation due to concentration of electric fields at gaps in the gridiron. This can provide a microwave heating device with higher efficiency which induces less energy losses.
  • the bridge members are placed such that arc portions of the bridge members are protruded to an outside of the outer frame.
  • the bridge members are structured such that their arc portions are protruded, and end portions of the bridge members are not protruded, which prevents abnormal heat generation from the gridiron. This can provide a microwave heating device with higher efficiency which induces less energy losses.
  • the gridiron is adapted to come in point-to-point contact with the heating chamber.
  • the gridiron is structured to create a larger gap which is less prone to induce concentrations of electric fields, over its portion other than its point-to-point contact portions.
  • the gridiron is structured such that it comes in point-to-point contact with the heating chamber, such that even a small gap is not induced between the gridiron and the heating chamber. With this structure, it is possible to prevent concentrations of electric fields, thereby suppressing abnormal heat generation. This can provide a microwave heating device with higher efficiency which induces less energy losses.
  • the outer frame is provided with a protruding portion, such that the gridiron comes in point-to-point contact with a rear-surface wall of the heating chamber.
  • the gridiron and the rear-surface wall of the heating chamber are made to come in line-to-line contact with each other over their contact surfaces, it is significantly hard to fabricate both the contact surfaces such that they are parallel with each other and, also, are straight. Thus, a small gap may be induced therebetween, and electric fields may be concentrated at these gaps.
  • the gridiron and the rear-surface wall of the heating chamber are structured such that they come in point-to-point contact with each other at their contact surfaces, which prevents concentrations of electric fields, thereby suppressing abnormal heat generation.
  • This can provide a microwave heating device with higher efficiency which induces less energy losses.
  • the rear-surface wall is provided with a protruding portion with a hemispherical shape, such that the gridiron comes in point-to-point contact with the rear-surface wall of the heating chamber.
  • the gridiron and the rear-surface wall of the heating chamber are made to come in line-to-line contact with each other over their contact surfaces, it is significantly hard to fabricate both the contact surfaces such that they are parallel with each other and, also, are straight. Thus, a small gap may be induced therebetween, and electric fields may be concentrated at these gaps.
  • the gridiron and the rear-surface wall of the heating chamber are structured such that they come in point-to-point contact with each other at their contact surfaces, which prevents concentrations of electric fields, thereby suppressing abnormal heat generation.
  • This can provide a microwave heating device with higher efficiency which induces less energy losses.
  • the protruding portion formed on the outer frame in the gridiron is formed by bending a portion of a rod-shaped member in a U shape.
  • the fourteenth invention having the aforementioned structure, it is possible to form the protruding portion as a point-to-point contact portion, only by bending the rod-shaped member in the gridiron in a U shape. This facilitates the fabrication, thereby reducing the fabrication costs. Further, in cases where the protruding portion is provided on the gridiron through welding, the protruding portion may come off therefrom during use.
  • the protruding portion is formed integrally with the gridiron, which prevents the protruding portion from coming off therefrom. This can provide a heating apparatus with higher reliability.
  • a rail portion which enables the gridiron to be inserted in the inside of the heating chamber, and the rail portion and the gridiron are adapted to come in point-to-point contact with each other.
  • the rail portion and the gridiron are made to come in line-to-line contact with each other over their contact surfaces, it is significantly hard to fabricate both the contact surfaces such that they are parallel with each other and, also, are straight. Thus, a small gap may be induced therebetween, and electric fields may be concentrated at these gaps.
  • the rail portion and the gridiron are structured such that they come in point-to-point contact with each other, which prevents concentrations of electric fields between the rail portion and the gridiron, thereby suppressing abnormal heat generation.
  • This can provide a heating apparatus with higher efficiency which induces less energy losses.
  • microwave heating devices having oven functions will be described as heating cookers, these microwave ovens are merely illustrative, and the microwave heating devices according to the present invention are not limited to such microwave ovens and also include various types of heating apparatuses which utilize induction heating.
  • the structures of heating cookers will be described in detail, but the present invention is not limited to the structures according to the embodiments and also includes structures based on technical concepts similar thereto.
  • Fig. 1 is a front cross-sectional view illustrating a microwave oven having oven functions, as a heating cooker which is a microwave heating device according to a first embodiment of the present invention.
  • the microwave oven having the oven functions includes, in its front surface, an openable door (not illustrated) for introducing and removing an object to be heated thereinto and therefrom and, further, includes a heating chamber 1 for performing microwave heating on the object 5 to be heated, which has been housed and enclosed therein through the door.
  • the heating chamber 1 for housing a food as an object 5 to be heated and for heating it is constituted by steel plates having surfaces coated with a porcelain enamel.
  • an upper heater 2 and a lower heater 3 are provided within the heating chamber 1.
  • a gridiron 4 is provided such that it can be introduced into and removed from the heating chamber 1, wherein the gridiron 4 is constituted by stainless-steel rod members combined with one another through welding.
  • a plurality of rails 12 and 13 are provided on the opposite side wall surfaces of the heating chamber 1, in order to enable placing the gridiron 4 at a plurality of positions in the upward and downward directions within the heating chamber 1.
  • an oven heating mode a food as an object 5 to be heated is placed on the gridiron 4 housed within the heating chamber 1 and is sandwiched between the upper heater 2 and the lower heater 3 to be heated thereby.
  • this oven heating mode between the gridiron 4 and the lower heater 3, it is also possible to provide a receiving plate for receiving juices exuded from the object 5 to be heated, during the roasting.
  • the heating chamber 1 is structured such that the corners of the inner wall surfaces have curved surfaces with R, and the bottom surface of the heating chamber 1 is formed to have a larger arc shape (in Fig. 1 , the curved-surface structure in the bottom surface is not illustrated). Further, although the first embodiment has been described with respect to an example where the wall surfaces of the heating chamber 1 are coated with a porcelain enamel, other heat-resistant coatings may be also applied thereto.
  • the gridiron 4 can be constituted by plated steel members and the like.
  • a magnetron 6 as a microwave generating portion is provided above the right side of the heating chamber 1, such that it generates outputs in the horizontal direction.
  • Microwaves generated from the magnetron 6 are propagated through a waveguide 14 and, further, are radiated within the heating chamber 1 through a rotational antenna 11 coupled to the waveguide 14.
  • the microwave heating device according to the first embodiment is adapted to perform heating operations, through microwave heating and through at least one of radiant heating and convection heating with the upper heater 2 and the lower heater 3, for performing heating processes on the food as the object 5 to be heated.
  • the microwave generating portion includes the antenna 11 and the waveguide 14 in addition to the magnetron 6 and, thus, includes means for generating microwaves and supplying the generated microwaves to the heating chamber 1.
  • the upper heater 2 is provided with an upper-heater thermocouple 7 as an upper-heater temperature detection portion, such that it is in contact with the surface of the upper heater 2.
  • the upper-heater thermocouple 7 is covered with a metal tube, in order not to be influenced by microwaves from the magnetron 6. This enables detection of the heater temperature of the upper heater 2 with higher accuracy.
  • the lower heater 3 is provided with a lower-heater thermocouple 8 as a lower-heater temperature detection portion, such that it is in contact with the surface of the lower heater 3.
  • a thermistor 9 as means for detecting the temperature within the heating chamber 1 is secured.
  • the upper-heater thermocouple 7, the lower-heater thermocouple 8 and the thermistor 9 are electrically connected to a control portion 10.
  • the control portion 10 controls the supply of electricity to the upper heater 2 and the lower heater 3, based on respective outputs from the upper-heater thermocouple 7, the lower-heater thermocouple 8 and the thermistor 9.
  • the heating cooker according to the first embodiment is structured to be capable of control for increasing and decreasing the amount of heating, in the oven heating mode.
  • the magnetron 6 has an output portion which is protruded in the horizontal direction and is coupled to an end portion of the waveguide 14.
  • the waveguide 14 includes a vertical portion including the end portion to which the output portion of the magnetron 6 is coupled, and a horizontal portion extending in the horizontal direction and, thus, is provided with an internal path having an L shape.
  • the waveguide 14 is provided with the rotational antenna 11 as a radio-wave stirring means, near the center of the heating chamber 1 in the horizontal direction.
  • the rotational antenna 11 has a shaft portion 11B which is mechanically coupled to the rotational shaft of a motor 18, so that an antenna portion 11A provided on an end portion of the shaft portion 11B is rotated through the shaft portion 11B of the rotational antenna 11 by driving the motor 18.
  • the waveguide 14 is provided with a feeding port 17, and a dome 15 with a conical shape is provided in such a way as to surround the feeding port 17.
  • the shaft portion 11B of the rotational antenna 11 penetrates through the feeding portion 17 in the waveguide 14, and the antenna portion 11A is placed within the dome 15.
  • the rotational antenna 11 is constituted by the antenna portion 11A and the shaft portion 11B, wherein the antenna portion 11A is formed, from a metal plate with a thickness of 1 mm, to have a substantially-disk shape with a diameter of about ⁇ 62. Further, the shaft portion 11B is secured to the antenna portion 11A, at a position deviated from the center of the disk by about 12 mm.
  • the shaft portion 11B has a portion formed from a fluorocarbon resin, which is closer to the motor 18, and, further, has a portion formed from a metal, which is closer to the antenna portion 11A.
  • the metal portion of the shaft portion 11B which is closer to the antenna portion 11A, penetrates through the feeding portion 17 in the dome 15 into the waveguide 14 by about 11 mm and, further, protrudes toward the heating chamber 1 by about 15 mm, and this protruding end portion is provided with the antenna portion 11A. There is secured a gap of 5 mm or more, between the shaft portion 11B and the feeding portion 17.
  • the heating cooker according to the first embodiment has been described with respect to an example where the magnetron 6, the rotational antenna 11, the waveguide 14, the dome 15 and the feeding portion 17 are provided above the heating chamber 1.
  • the present invention is not limited to this structure and, for example, they can be provided near the bottom surface of the heating chamber 1 or near the side surfaces thereof.
  • the waveguide 14 and the like can be installed in any orientations.
  • the heating cooker according to the first embodiment is provided with a cover 16 made of a mica, at the lower end portion of the dome 15, in order to prevent contaminations from the object 5 to be heated from adhering to the rotational antenna 11.
  • the cover 16 is formed such that it can be attached to and detached from a hook 19 made of an insulating material, which is secured to the heating chamber 1.
  • the upper heater 2 is placed such that it evades the position beneath the lower opening portion in the dome 15, in order that the upper heater 2 is not directly influenced by microwaves.
  • the structure according to the first embodiment has been described with respect to an example where the cover 16 is formed from a mica, which is a low loss dielectric material, it can be similarly formed from ceramics or glasses.
  • Fig. 2 is a plan view illustrating the gridiron 4 in the heating cooker as the microwave heating device according to the first embodiment of the present invention.
  • the lower side corresponds to the user side (the door side) of the heating cooker, while the upper side corresponds to the rear-surface side.
  • Fig. 2 illustrates an example of standing waves SW induced within the heating chamber 1, in a contour-line manner, wherein areas hatched in a dark color represent areas in which the standing waves have larger amplitudes (areas in which there are larger electric fields : MA).
  • the gridiron 4 is constituted by an outer frame 21 formed from a rod member with a diameter of ⁇ 6 which is made of a metal, and a plurality of bridge members 20 (20A, 20B) formed from rod members with a diameter of ⁇ 3 which are made of a metal.
  • insulating members 22 are secured to the left and right opposite side portions (21B) of the outer frame 21.
  • two bridge members 20A are provided in parallel with the front and rear opposite side portions (21A) of the outer frame 21, in such a way as to form bridges between the left and right opposite side portions (21B) of the outer frame 21.
  • twelve bridge members 20B are bonded, through welding, to the two bridge members 20A in such a way as to orthogonally form bridges therebetween, at predetermined intervals which will be described later.
  • the intervals between the left and right opposite side portions (21B) of the outer frame 21 and the respective bridge members 20B at the opposite ends are set to be equal to or more than about 3/8 the wavelength ⁇ of standing waves SW. Further, as illustrated in Fig. 2 , the twelve bridge members 20B are placed in such a way as to interpose a larger interval (a first interval : A) between each three bridge members 20B and the other three bridge members 20B adjacent thereto. Further, the intervals between the respective three bridge members are set to be second intervals B.
  • the first intervals A are placed in such a way as to sandwich, therebetween, the vicinities of antinodes MA at which standing waves SW have larger amplitudes and there are 80 % or more of a largest electric field and, further, the first intervals A are set to be about 1/4 the wavelength ⁇ of standing waves SW. Further, the second intervals B, which are the smaller intervals between the bridge members 20B, are set to be about 1/8 the wavelength ⁇ of standing waves SW.
  • standing waves are wave motions induced inside the heating chamber and are, basically, induced by superimposition of waves radiated from the antenna and waves reflected by the inner wall surfaces of the heating chamber.
  • Such standing waves are wave motions which hardly involve waveform progressions and seem to vibrate while staying at the current positions. Accordingly, such standing waves are induced in a state which is determined to some degree by the structure of the heating chamber, the structure of the antenna and the like.
  • the heating cooker according to the first embodiment is structured such that, in the heating space in the heating chamber 1, the bridge members 20B are at different intervals (the first intervals A and the second intervals B), in the areas which sandwich the vicinities of antinodes MA of standing waves and in the other areas, as described above.
  • the bridge members 20B it is necessary only that the bridge members 20B are placed in areas which evade the vicinities of antinodes MA of standing waves SW which are induced within the heating chamber 1. Provided that this condition is satisfied, the bridge members 20B can be also at even intervals, which can also offer the same effects.
  • the wavelength of standing waves SW is changed depending on the shape of the internal space within the heating chamber 1.
  • the wavelength of standing waves SW in the leftward and rightward direction in the heating chamber 1 is about 14 cm. Accordingly, 3/8 the wavelength ⁇ of standing waves is about 5.3 cm, 1/4 ⁇ is about 3.5 cm, and 1/8 ⁇ is about 1.8 cm.
  • standing waves SW which are induced within the heating chamber 1 are also changed by the food as the object 5 to be heated, which is being placed on the gridiron 4, as well as by the structure of the inner surfaces of the heating chamber 1.
  • the positions at which the vicinities of antinodes MA of standing waves SW are induced are not largely changed.
  • Fig. 3 is a schematic cross-sectional view of the gridiron 4 illustrated in Fig. 2 , taken along the line III-III, schernatically illustrating a standing wave SW which is induced within the heating chamber 1.
  • a standing wave SW having node positions and antinode positions, wherein, at the node positions, its amplitude is zero since electric fields are superimposed on each other and, thus, are hardly vibrated, while, at the antinode positions, its amplitude is largely changed.
  • the heating cooker according to the first embodiment four bridge members 20B, out of the bridge members 20B in the gridiron 4, are placed in the vicinities of nodes of standing waves SW.
  • the insulating members 22 constituted by insulators are secured to the outer frame 21 in such a way as to pinch the outer frame 21 therein and, further, these insulating members 22 are adapted to be slidable on the plurality of rails 12 (12A and 12B) secured to the heating chamber 1. Accordingly, the insulating members 22 electrically insulate the rails 12 and the outer frame 21 in the gridiron 4 from each other and, also, electrically insulate the outer frame 21 and the heating chamber 1 from each other.
  • the standing wave SW illustrated in Fig. 3 there is illustrated a standing wave SW having five antinodes and six nodes
  • the numbers of antinodes and nodes in the standing wave SW and the intervals therebetween are varied, depending on various conditions in the heating chamber and the like. Accordingly, the structure of the gridiron 4 should be properly changed, according to the specifications of the heating cooker.
  • the term "the wavelength ⁇ of a standing wave” refers to the periodic length including two antinodes and two nodes, and the periodic length including a single antinode and a single node corresponds to 1 / 2 the wavelength.
  • Fig. 4 is a main-part cross-sectional view of structures, such as the gridiron 4 and the like, within the heating chamber 1, taken along the line IV-IV in Fig. 2 .
  • the left side corresponds to the front-surface side provided with the door, while the right side corresponds to the rear-surface side of the heating chamber 1.
  • the outer frame 21 in the gridiron 4 is placed such that it is sandwiched, upwardly and downwardly, between the lower rails 12 (12A and 12B) and the upper rail 13. Since the gridiron 4 is sandwiched between the upper and lower rails 12 and 13 as described above, the gridiron 4 is prevented from being inclined halfway through being pulled outwardly from the heating chamber 1.
  • the magnetron 6 In the heating cooker according to the first embodiment, if a user selects a microwave heating mode and, further, turns on a switch for starting heating operations, the magnetron 6 generates microwaves, and the microwaves from the magnetron 6 are propagated through the waveguide 14.
  • the microwaves having propagated through the waveguide 14 are directed to the rotational antenna 11 and, further, are supplied to the inside of the heating chamber 1 while being stirred by the rotational antenna 11 which is being rotated by the motor 18.
  • Microwaves having been supplied to the inside of the heating chamber 1 are directed to the object 5 to be heated, such as a food, and the food absorbs microwaves, so that the food is heated by the microwaves.
  • the heating cooker according to the first embodiment if the user selects the oven heating mode and, further, turns on the switch for starting heating operations, the upper heater 2 and the lower heater 3 are supplied with electricity and, thus, are caused to generate heat. Since the upper heater 2 and the lower heater 3 generate heat, radiant heat from the upper heater 2 and the lower heater 3 is transmitted to the food within the heating chamber 1, so that this food is heated in an oven manner.
  • the gridiron 4 for placing the object 5 to be heated thereon for performing heating cooking thereon, which is placed within the heating chamber 1 is formed to have a shape, in consideration of standing waves SW which are induced within the heating chamber 1. More specifically, the gridiron 4 is formed to be opened in the vicinities of antinodes of standing waves SW which are induced within the heating chamber 1 and, thus, the outer frame 21 and the bridge members 20 in the gridiron 4 are provided in areas outside the vicinities of antinodes MA of standing waves SW induced within the heating chamber 1, in such a way as to evade the vicinities of antinodes MA.
  • the outer frame 21 and the bridge members 20 in the gridiron 4 are not provided in areas in which there are larger electric fields in the microwave heating mode, which prevents abnormally-larger electric currents from flowing through the gridiron 4 in the microwave heating mode, thereby largely suppressing heat generation from the gridiron 4.
  • This can provide a heating cooker with higher efficiency which induces less energy losses.
  • the bridge members 20B are placed near nodes of standing waves SW which are induced within the heating chamber 1. Accordingly, larger electric currents are not flowed through the bridge members 20B provided near the nodes, which causes these bridge members 20B to generate less heat in the microwave heating mode. This can realize higher efficiency in the entire heating cooker.
  • the bridge members 20A and 20B are spaced apart from the inner wall surfaces of the heating chamber 1, by lengths equal to or more than 3/8 the wavelength ⁇ of standing waves SW.
  • the bridge members 20A and 20B are not placed in the areas at a distance equal to 1/4 the wavelength ⁇ of standing waves SW from the inner wall surfaces of the heating chamber 1, which are coincident with the positions of antinodes of standing waves SW induced within the heating chamber 1. Therefore, in the microwave heating mode, it is possible to suppress heat generation from the gridiron 4, thereby realizing higher efficiency.
  • the gridiron 4 has the insulating structure having the insulating members 22 provided between the outer frame 21 and the lower rails 12 and between the outer frame 21 and the heating chamber 1. If the gridiron 4 were not insulated, this would cause concentration of electric fields in smaller gaps, thereby inducing abnormal heat generation therefrom.
  • the gridiron 4 has the insulating structure, which can certainly provide insulation between the rails 12 and the gridiron 4 and between the heating chamber 1 and the rails 12, thereby suppressing electric-field concentrations and suppressing heat generation. This can realize higher efficiency.
  • the heating cooker according to the first embodiment has been described with respect to an example where there is an insulating structure between the gridiron 4 and the side walls of the heating chamber 1, it is also possible to provide an insulating structure between the gridiron 4 and the rear-surface wall of the heating chamber 1, which can further suppress heat generation from the gridiron 4.
  • the microwave heating device according to the present invention can suppress abnormal heat generation from the grid member and the like which are placed within the heating chamber. This can provide a heating apparatus with higher efficiency which induces less energy losses.
  • the conventional gridiron 102 is constituted by the plurality of metal rod-shaped members 104 which are densely placed. Accordingly, as illustrated in Fig. 13 , the conventional gridiron 102 is structured such that the plurality of rod-shaped members 104 are exposed within the heating chamber, at their protruding end surfaces 104a and 104b. Therefore, in the microwave heating mode, electric fields are concentrated in the protruding end surfaces 104a and 104b of the rod-shaped members 104, which induces heat generation, thereby inducing significant energy losses therein. This has caused degradations of the heating efficiency of the heating cooker.
  • a microwave heating device is a heating apparatus with higher heating efficiency which includes a gridiron 4 formed in consideration of standing waves SW induced within the heating chamber 1 as described in the aforementioned first embodiment and, further, alleviates concentrations of electric fields in the gridiron 4, thereby further reducing energy losses.
  • a heating cooker as a microwave heating device according to the second embodiment of the present invention, with reference to the accompanying drawings.
  • the heating cooker according to the second embodiment will be described hereinafter with respect to a microwave oven having oven functions, the microwave oven is merely illustrative, and the microwave heating device according to the present invention is not limited to such a microwave oven and also includes heating apparatuses which utilize induction heating.
  • the heating cooker as the microwave heating device according to the second embodiment is different from the structure according to the first embodiment, in terms of the shape and the structure of the gridiron 4, but the other structures are the same as those of the heating cooker according to the first embodiment. Accordingly, the second embodiment will be described with respect to the shape and the structure of the gridiron 4.
  • Figs. 5 to 8 illustrate plan views of four types of gridirons (4A, 4B, 4C and 4D) for use in the heating cooker according to the second embodiment of the present invention.
  • the gridiron 4A illustrated in Fig. 5 is constituted by an outer frame 21 with a substantially-rectangular shape, and a plurality of bridge members 200A formed to have an annular elongated track shape. As illustrated in Fig. 5 , the plurality of bridge members 200A are placed in parallel with each other and, further, are provided in such a way as to form bridges between the opposite longer side portions of the outer frame 21 having the substantially-rectangular shape. In the gridiron 4A illustrated in Fig. 5 , the bridge members 200A are placed such that the straight-line portions in their longitudinal portions extend up to the outside of the outer frame 21 and, further, the bridge members 200A are adapted such that their arc portions at the opposite ends are not intersected with the outer frame 21.
  • the gridiron 4A illustrated in Fig. 5 is constituted by the outer frame 21 formed from a metal rod member with a diameter of ⁇ 6, and the bridge members 200A formed from metal rod members with a diameter of ⁇ 3.
  • the five bridge members 200A provided in such a way as to form bridges between the opposite longer side portions of the outer frame 21 are formed to have an annular elongated track shape (a substantially track elliptical shape), the straight-line portions of the bridge members 200A extend up to the outside of the outer frame 21, and the arc portions of the bridge members 200A at the opposite ends are placed outside the outer frame 21.
  • the gridiron 4B illustrated in Fig. 6 is constituted by an outer frame 21 with a substantially-rectangular shape, and a plurality of bridge members 200B formed to have an annular elongated track shape. As illustrated in Fig. 6 , the plurality of bridge members 200B are placed in parallel with each other and, further, are bonded to the opposite longer side portions of the outer frame 21 having the substantially-rectangular shape.
  • the gridiron 4B illustrated in Fig. 6 is adapted such that the respective bridge members 200B are in contact with the inner side of the outer frame 21. Namely, in the gridiron 4B illustrated in Fig.
  • the respective bridge members 200B having the annular elongated track shape are bonded to the outer frame 21, such that each of their arc portions at the opposite end portions is in contact with the inner side of the outer frame 21 at a single point on its outer periphery.
  • the gridiron 4B illustrated in Fig. 6 is constituted by the outer frame 21 formed from a metal rod member with a diameter of ⁇ 6, and the bridge members 200B formed from metal rod members with a diameter of ⁇ 3.
  • the five bridge members 200B provided in such a way as to form bridges between the opposite longer side portions of the outer frame 21 are formed to have an annular elongated track shape (a substantially track elliptical shape), and the bridge members 200B are bonded to the outer frame 21 such that their arc shaped portions are in contact with the inner side of the outer frame 21.
  • the gridiron 4C illustrated in Fig. 7 is constituted by an outer frame 21 with a substantially-rectangular shape, and a bridge member 200C formed to have a turned-back meandering shape.
  • the straight-line portions of the bridge member 200C extend up to the outside of the outer frame 21, and the bridge member 200C is structured such that its arc portions at the opposite end portions are not intersected with the outer frame 21.
  • the gridiron 4C illustrated in Fig. 7 is constituted by the outer frame 21 formed from a metal rod member with a diameter of ⁇ 6, and the bridge member 200C formed from a metal rod member with a diameter of ⁇ 3.
  • the bridge member 200C in a turned-back meandering shape is bonded to the outer frame 21, the straight-line portions of the bridge member 200C extend up to the outside of the outer frame 21, and the arc portions of the bridge member 200C are placed outside the outer frame 21.
  • the opposite end portions of the bridge member 200C having the turned-back meandering shape are bonded to the outer frame 21 and, preferably, are bonded to the inner side of the outer frame 21.
  • the gridiron 4D illustrated in Fig. 8 is constituted by an outer frame 21 with a substantially-rectangular shape, and a bridge member 200D formed to have a turned-back meandering shape. As illustrated in Fig. 8 , the bridge member 200D is bonded, at their arc portions, in a butting manner, to the outer frame 21, and the arc portions of the bridge member 200D are bonded to the outer frame 21 such that their outer peripheries are in contact with the inner surface of the outer frame 21.
  • the gridiron 4D illustrated in Fig. 8 is constituted by the outer frame 21 formed from a metal rod member with a diameter of ⁇ 6, and the bridge member 200D formed from a metal rod member with a diameter of ⁇ 3.
  • the bridge member 200D is provided in a turned-back meandering shape inside the outer frame 21, and the arc portions of the bridge member 200D are bonded to the inner side of the outer frame 21, in a butting manner. Further, the bridge member 200D having the turned-back meandering shape is bonded at their opposite end portions to the inner side of the outer frame 21.
  • the intervals between the rod-shaped members in the bridge members 200A to 200D in the gridirons 4A to 4D are set to have lengths equal to or more than about 1/4 the wavelength ⁇ of standing waves.
  • the numbers of the rod-shaped members in the gridirons 4 are properly changed, according to the size of the heating chamber 1, and the object to be heated, which is placed thereon.
  • Fig. 9 is a main-part cross-sectional view of the heating cooker according to the second embodiment, when viewed at a side surface thereof.
  • Fig. 9 illustrates a case where the gridiron 4B illustrated in Fig. 6 is employed.
  • the left side corresponds to the front-surface side provided with the door, while the right side corresponds to the rear-surface side of the heating chamber 1.
  • the outer frame 21 in the gridiron 4 (4A to 4D) is placed such that it is sandwiched, upwardly and downwardly, between lower rails 12 and an upper rail 13.
  • the upper rail 13 prevents the gridiron 4 from being inclined halfway through being pulled outwardly from the heating chamber 1.
  • the gridiron 4 is provided, on its lower side, with hemispherical portions 23 which come in point-to-point contact with the rails 12, at two positions in each single side and, thus, at four positions in the left and right sides.
  • a magnetron 6 In the heating cooker according to the second embodiment, if a user selects a microwave heating mode and, further, turns on a switch for starting heating operations, a magnetron 6 generates microwaves, and the microwaves from the magnetron 6 are propagated through a waveguide 14.
  • the microwaves having propagated through the waveguide 14 are directed to a rotational antenna 11 and, further, are supplied to the inside of the heating chamber 1 while being stirred by the rotational antenna 11 being rotated by a motor 18.
  • Microwaves having been supplied to the inside of the heating chamber 1 are directed to the object 5 to be heated, such as a food, and the food absorbs microwaves, so that the food is heated by the microwaves.
  • the heating cooker according to the second embodiment if the user selects the oven heating mode and, further, turns on the switch for starting heating operations, an upper heater 2 and a lower heater 3 are supplied with electricity and, thus, are caused to generate heat. Since the upper heater 2 and the lower heater 3 generate heat, radiant heat from the upper heater 2 and the lower heater 3 are transmitted to the food within the heating chamber 1, so that this food is heated in an oven manner.
  • the gridiron 4 is structured to have no protruding end surface with acuteness, and the gridiron 4 is constituted by the members having the annular elongated shape or the turned-back meandering shape, which largely restricts portions of the gridiron 4 which cause concentrations of electric fields therein.
  • the heating cooker according to the second embodiment forms a heating cooker with higher efficiency which is capable of suppressing heat generation from the gridiron 4, thereby inducing less energy losses.
  • the heating cookers having the structures illustrated in Fig. 6 and Fig. 8 are adapted to alleviate concentrations of electric fields, which can further reduce energy losses. Therefore, these heating cookers form heating cookers with higher heating efficiency.
  • the bridge member 200D is formed to have a turned-back meandering shape, the arc portions of the bridge member 200D are bonded to the inner side of the outer frame 21 in a butting manner, and the arc portions of the bridge member 200D are bonded, at their outer peripheries, to the inner periphery of the outer frame 21 such that they are in contact with each other. Therefore, with the heating cooker having the structure illustrated in Fig. 8 , the gridiron 4 can be formed to have a smaller thickness and, further, the gridiron 4 is formed to have opposite surfaces which are capable of placing objects 5 to be heated thereon and have less level differences therein, thereby offering the advantage of ease of cleaning.
  • the bridge members 200A to 200D are placed such that their longitudinal directions are coincident with the forward and rearward direction of the heating chamber 1, the bridge members 200A to 200D can be also placed such that their longitudinal directions are coincident with any directions, such as the leftward and rightward direction of the heating chamber 1, oblique directions of the heating chamber 1, and the like, which can also offer the same effects.
  • the intervals between the rod-shaped members in the bridge members 20 in the gridiron 4 are set to be equal to or more than 1/4 ⁇ , microwaves are caused to come around to below the gridiron 4, and the object 5 to be heated is caused to absorb microwaves from therebelow, so that the heating cooker according to the second embodiment is adapted to realize higher efficiency.
  • the gridiron 4 is provided with the hemispherical portions 23 such that they can slide on the lower rails 12.
  • the outer frame 21 and the rails 12 are brought into line-to-line contact with each other.
  • electric fields are liable to be concentrated at the slight gaps induced between the contact surfaces of the outer frame 21 and the rails 12, thereby causing significant energy losses.
  • the gridiron 4 is provided with the hemispherical portions 23, so that the hemispherical portions 23 in the gridiron 4 come in contact with the lower rails 12 at two positions in each single side and, thus, come in point-to-point contact therewith at four positions, in total, in the left and right sides. Therefore, the outer frame 21 in the gridiron 4 is placed in such a way as to interpose a larger gap between it and the rails 12, over its portions other than the portions which come in point-to-point contact with the rails 12. Accordingly, in the structure according to the second embodiment, there is a larger gap between the gridiron 4 and the rails 12 over their entirety, which prevents concentrations of electric fields between the gridiron 4 and the rails 12, thereby realizing higher efficiency.
  • the structure according to the second embodiment has been described with respect to an example where the gridiron 4 is provided with the hemispherical portions 23 at two positions in each single side and, therefore, at four positions in the left and right sides.
  • the present invention is not limited to this structure. It is possible to support the gridiron 4 at least at three positions, and it is also possible to increase the number of the hemispherical portions 23 for improving the balance of the gridiron 4 when objects 5 to be heated are placed thereon, which can also offer the same effects.
  • the structure according to the second embodiment has been described with respect to an example where the gridiron 4 is provided with the hemispherical portions 23, it is also possible to provide insulating members thereon, instead of the hemispherical portions 23, in order to prevent concentrations of electric fields.
  • these insulating members can be provided on the roasting gird 4 in areas between it and the lower rails 12, and in areas near the wall surfaces of the heating chamber 1, which can prevent concentrations of electric fields, thereby increasing the heating efficiency.
  • the upper rails 12 (12A and 12B) and the lower rail 13 are placed, such that they are staggered with respect to each other. Since the upper rails 12 (12A and 12B) and the lower rail 13 are placed such that they are staggered with respect to each other as described above, it is possible to prevent the occurrence of concentrations of electric fields between the rails, thereby realizing higher efficiency.
  • the wall surfaces of the heating chamber 1 are formed such that their corner portions have curved surfaces (R), and the bottom surface is formed to have a larger arc shape. Therefore, microwaves reflected by the wall surfaces of the heating chamber 1 are directed toward the object 5 to be heated, so that the object 5 to be heated is liable to be irradiated with the reflected waves, which enables heating with higher efficiency.
  • the microwave heating device is adapted such that the rod-shaped members in the gridiron are less exposed at their end surfaces within the heating chamber, which alleviates concentrations of electric fields, thereby reducing heat generation from the gridiron. This enables heating cooking with higher efficiency and with lower energy losses.
  • a microwave heating device is structured such that a gridiron 4 is provided with hemispherical portions and, also, is structured to alleviate the occurrence of concentrations of electric fields between the gridiron 4 and the heating chamber 1.
  • the outer frame 21 in the gridiron 4 and the lower rails 12 are brought into line-to-line contact with each other.
  • electric fields are liable to be concentrated at the slight gaps induced between these contact surfaces, thereby inducing significant energy losses. This results in the problem of degradations of the heating efficiency of the heating cooker.
  • the structure which provides the insulating members 22 has the problem that the number of members is increased, which involves an increase of fabrication processes, thereby increasing the cost of the apparatus.
  • the gridiron 4 is caused to have an increased weight, which has caused the problem of an increase of the difficulty of handling thereof.
  • the microwave heating device is made to overcome the aforementioned problems and, thus, forms a lower-cost and higher-efficiency heating apparatus which induces lower energy losses and, further, is easy to handle.
  • the heating cooker as the microwave heating device according to the third embodiment is different from the structure according to the first embodiment, in terms of the shape and the structure of a gridiron 4, but the other structures are the same as those of the heating cooker according to the first embodiment. Accordingly, the third embodiment will be described, with respect to the shape and the structure of the gridiron 4.
  • Fig. 10 is a plan view illustrating the gridiron 4E in the heating cooker according to the third embodiment of the present invention.
  • the gridiron 4E illustrated in Fig. 10 is constituted by an outer frame 21 formed from a rod member with a diameter of ⁇ 6 which is made of a metal, and bridge members 20 formed from rod members with a diameter of ⁇ 3 which are made of a metal.
  • the eight bridge members 20 are provided in such a way as to form bridges between the opposite longer side portions of the outer frame 21 with a substantially-rectangular shape.
  • the outer frame 21 is provided with two protruding portions 21C with a U shape, such that they protrude toward the rear-surface wall 1A of the heating chamber 1.
  • the two protruding portions 21C are provided in the outer frame 21 near the left and right end portions at positions faced to the rear-surface wall 1A of the heating chamber 1, wherein these protruding portions 21C have been formed by performing a bending process on the outer frame 21.
  • the two protruding portions 21C come in point-to-point contact with the rear-surface wall 1A of the heating chamber 1.
  • the gap L between the rear-surface wall 1A of the heating chamber 1 and the portion of the outer frame 21 near the rear-surface wall 1A is set to be about 5 mm, except the portions of the protruding portions 21C.
  • the intervals between the rod-shaped members in the bridge members 20 in the gridiron 4E are set to have lengths equal to or more than about 1/4 the wavelength ⁇ of standing waves. Further, in the structure according to the third embodiment, the number of the rod-shaped members in the gridiron 4 is properly changed, according to the size of the heating chamber 1, and the object to be heated, which is placed thereon.
  • Fig. 11 is a main-part cross-sectional view of the heating cooker according to the third embodiment, when viewed at a side surface thereof.
  • the left side corresponds to the front-surface side provided with the door, while the right side corresponds to the rear-surface side of the heating chamber 1.
  • the outer frame 21 in the gridiron 4E is placed such that it is sandwiched, upwardly and downwardly, between lower rails 12 and an upper rail 13.
  • the upper rail 13 prevents the gridiron 4E from being inclined halfway through being pulled outwardly from the heating chamber 1.
  • the outer frame 21 is provided, on its lower side, with hemispherical portions 23 which come in point-to-point contact with the rails 12, at two positions in each single side and, thus, at four positions in the left and right sides.
  • the gap L is set to be about 5 mm, but it can be at least 3 mm or more, which can prevent concentrations of electric fields.
  • a magnetron 6 generates microwaves, and the microwaves from the magnetron 6 are propagated through a waveguide 14.
  • the microwaves having propagated through the waveguide 14 are directed to a rotational antenna 11 and, further, are supplied to the inside of the heating chamber 1 while being stirred by the rotational antenna 11 being rotated by a motor 18.
  • Microwaves having been supplied to the inside of the heating chamber 1 are directed to the object 5 to be heated, such as a food, and the food absorbs microwaves, so that the food is heated by the microwaves.
  • the heating cooker according to the third embodiment if the user selects the oven heating mode and, further, turns on the switch for starting heating operations, the upper heater 2 and the lower heater 3 are supplied with electricity and, thus, are caused to generate heat. Since the upper heater 2 and the lower heater 3 generate heat, radiant heat from the upper heater 2 and the lower heater 3 are transmitted to the food within the heating chamber 1, so that this food is heated in an oven manner.
  • the gridiron 4 is provided with the hemispherical portions 23 such that they can slide on the rails 12.
  • the outer frame 21 and the lower rails 12 are brought into line-to-line contact with each other.
  • electric fields are liable to be concentrated at the slight gaps induced between the contact surfaces of the outer frame 21 and the rails 12, thereby inducing significant energy losses.
  • the gridiron 4 is provided with the hemispherical portions 23, so that the hemispherical portions 23 in the gridiron 4 come in contact with the lower rails 12 at two points in each single side and, thus, come in point-to-point contact therewith at four points, in total, in the left and right sides. Therefore, the outer frame 21 in the gridiron 4 is placed in such a way as to interpose a larger gap between it and the rails 12, over its portion other than the portions which come in point-to-point contact with the rails 12. Accordingly, in the structure according to the third embodiment, there is formed a larger gap (of 5 mm or more) between the gridiron 4 and the rails 12, which prevents concentrations of electric fields between the gridiron 4 and the rails 12, thereby realizing higher efficiency.
  • the structure according to the third embodiment has been described with respect to an example where the gridiron 4 is provided with the hemispherical portions 23 at two positions in each side and, therefore, at four positions in the left and right sides.
  • the present invention is not limited to this structure. It is possible to support the gridiron 4 at least at three positions, and it is also possible to increase the number of the hemispherical portions 23 for improving the balance of the gridiron 4 when objects 5 to be heated are placed thereon, which can also offer the same effects.
  • the gridiron 4 is brought into point-to-point contact with the rails 12, which reduces the friction between the gridiron 4 and the rails 12, thereby offering the advantage that the gridiron 4 can be easily pulled out.
  • the outer frame 21 is provided with the U-shaped protruding portions 21C, so that the gridiron 4 comes in point-to-point contact with the rear-surface wall 1A of the heating chamber 1, only at the protruding portions 21C. Therefore, the outer frame 21 is placed in such a way as to interpose a larger gap between it and the rear-surface wall 1C of the heating chamber 1, over its potion other than the protruding portions 21C. Accordingly, with the structure according to the third embodiment, it is possible to prevent concentrations of electric fields between the gridiron 4 and the heating chamber 1, thereby realizing higher efficiency.
  • the protruding portions 21C formed in the outer frame 21 can be formed only by bending the outer frame 21 into a U shape. This facilitates the fabrication thereof, which can reduce the fabrication costs. Furthermore, the protruding portions 21C are formed integrally with the outer frame 21 and, therefore, cannot be separated from the outer frame 21. This can provide the gridiron 4 with higher reliability.
  • the structure according to the third embodiment has been described with respect to an example where the gridiron 4 is provided with the U-shaped protruding portions 21 at two positions, it is also possible to increase the number of the protruding portions 21C, in order to prevent the gridiron 4 from being deformed when being strongly pressed against the rear-surface wall 1C.
  • the protruding portions 21C can have any shapes which can alleviate concentrations of electric fields and, thus, can be formed to have semicircular shapes, triangular shapes and the like, as well as U shapes, which can also offer the same effects.
  • the structure according to the third embodiment has been described with respect to an example where the gridiron 4 is provided with the protruding portions 21C, it is also possible to provide them on the rear-surface wall of the heating chamber 1.
  • protrusions with a hemispherical shape can be formed on the rear-surface wall of the heating chamber 1 such that the outer frame 21 of the gridiron 4 comes in point-to-point contact with these protrusions.
  • the structure according to the third embodiment has been described with respect to an example where the hemispherical portions 23 are formed from additional members, it is also possible to perform a bending process on the outer frame 21 in the gridiron 4 such that it is protruded downwardly in a U shape. In this case, it is possible to provide the same effects as those provided by provision of the hemispherical portions 23 and, furthermore, it is possible to simplify the structure, thereby reducing the fabrication costs.
  • the structure according to the third embodiment has been described with respect to an example where the gap between the outer frame 21 of the gridiron 4 and the rear-surface wall 1A of the heating chamber 1, and the gap between the outer frame 21 and the lower rails 12 are set to be about 5 mm, except the portions which are in point-to-point contact with each other.
  • these gaps can be set to be only 3 mm or more, which can suppress concentrations of electric fields, thereby offering substantially the same effects.
  • the intervals between the rod-shaped members in the bridge members 20 in the gridiron 4 are set to be equal to or more than 1/4 ⁇ , so that microwaves are caused to come around to below the gridiron 4 and, thus, the object 5 to be heated is caused to absorb microwaves from therebelow. Therefore, the heating cooker according to the third embodiment is structured to realize higher efficiency.
  • the upper rails 12 (12A and 12B) and the lower rail 13 are placed, such that they are staggered with respect to each other. Since the upper rails 12A and 12B and the lower rail 13 are placed such that they are staggered with respect to each other as described above, it is possible to prevent the occurrence of concentrations of electric fields between the rails, thereby realizing higher efficiency.
  • the wall surfaces of the heating chamber 1 are formed such that their corner portions have curved surfaces (R), and the bottom surface is formed to have a larger arc shape. Therefore, microwaves reflected by the wall surfaces of the heating chamber 1 are directed toward the object 5 to be heated, so that the object 5 to be heated is liable to be irradiated with the reflected waves, which enables heating with higher efficiency.
  • the microwave heating device is capable of preventing the occurrence of concentrations of electric fields in slight gaps and, thus, forms a heating apparatus with higher efficiency which can suppress abnormal heat generation from the gridiron, thereby inducing less energy losses.
  • the microwave heating device is capable of heating with higher efficiency and with less energy losses and, therefore, is applicable to microwave ovens, oven-type microwave ovens and electric ovens as cooking appliances which utilize microwave functions and, also, is applicable to commercial microwave heating devices of various types, such as, for example, heating apparatuses in industrial fields, such as thawing apparatuses and drying apparatuses, ceramic-art heating and sintering apparatuses, biochemical reaction apparatuses, and the like.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Electric Ovens (AREA)
EP11843277.2A 2010-11-25 2011-11-18 Dispositif de chauffage à micro-ondes Not-in-force EP2645001B1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2010261961 2010-11-25
JP2010264550 2010-11-29
JP2011052660 2011-03-10
PCT/JP2011/006434 WO2012070211A1 (fr) 2010-11-25 2011-11-18 Dispositif de chauffage à micro-ondes

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EP2645001A1 true EP2645001A1 (fr) 2013-10-02
EP2645001A4 EP2645001A4 (fr) 2014-05-07
EP2645001B1 EP2645001B1 (fr) 2015-06-10

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Publication number Priority date Publication date Assignee Title
CN113260105A (zh) * 2021-05-27 2021-08-13 广东美的厨房电器制造有限公司 烹饪器具的微波发生系统和烹饪器具

Citations (2)

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Publication number Priority date Publication date Assignee Title
US3798404A (en) * 1972-12-21 1974-03-19 Gen Electric Electronic oven with mode exciter
DE3040113A1 (de) * 1980-10-24 1982-05-27 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt Kombinierter herd fuer mikrowellen- und konventionellen wiederstands-heizbetrieb

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Publication number Priority date Publication date Assignee Title
JPS5559209A (en) 1978-10-26 1980-05-02 Tokyo Shibaura Electric Co Automatic snow melting system
JP2951001B2 (ja) * 1990-12-07 1999-09-20 三洋電機株式会社 マイクロ波加熱装置
JPH09145064A (ja) 1995-11-21 1997-06-06 Toshiba Corp オーブン機能付き電子レンジ
JP3063643B2 (ja) * 1996-10-09 2000-07-12 松下電器産業株式会社 加熱装置
JP2004360986A (ja) * 2003-06-04 2004-12-24 Matsushita Electric Ind Co Ltd ヒータ付き高周波加熱調理器

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3798404A (en) * 1972-12-21 1974-03-19 Gen Electric Electronic oven with mode exciter
DE3040113A1 (de) * 1980-10-24 1982-05-27 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt Kombinierter herd fuer mikrowellen- und konventionellen wiederstands-heizbetrieb

Non-Patent Citations (1)

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Title
See also references of WO2012070211A1 *

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EP2645001A4 (fr) 2014-05-07
JP5874040B2 (ja) 2016-03-01
EP2645001B1 (fr) 2015-06-10
JPWO2012070211A1 (ja) 2014-05-19
WO2012070211A1 (fr) 2012-05-31

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