EP0277342B1 - Procédé et dispositif pour homogénéiser l'échauffement d'aliments dans un appareil de cuisson chauffant à micro-ondes - Google Patents

Procédé et dispositif pour homogénéiser l'échauffement d'aliments dans un appareil de cuisson chauffant à micro-ondes Download PDF

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Publication number
EP0277342B1
EP0277342B1 EP87118985A EP87118985A EP0277342B1 EP 0277342 B1 EP0277342 B1 EP 0277342B1 EP 87118985 A EP87118985 A EP 87118985A EP 87118985 A EP87118985 A EP 87118985A EP 0277342 B1 EP0277342 B1 EP 0277342B1
Authority
EP
European Patent Office
Prior art keywords
rotating element
rear wall
wave guide
microwaves
cooking chamber
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.)
Expired - Lifetime
Application number
EP87118985A
Other languages
German (de)
English (en)
Other versions
EP0277342A3 (en
EP0277342A2 (fr
Inventor
Gerd Dr. Naumann
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Electrolux Juno Kuchentechnik GmbH
Original Assignee
Electrolux Juno Kuchentechnik GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Electrolux Juno Kuchentechnik GmbH filed Critical Electrolux Juno Kuchentechnik GmbH
Priority to AT87118985T priority Critical patent/ATE91375T1/de
Publication of EP0277342A2 publication Critical patent/EP0277342A2/fr
Publication of EP0277342A3 publication Critical patent/EP0277342A3/de
Application granted granted Critical
Publication of EP0277342B1 publication Critical patent/EP0277342B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • H05B6/70—Feed lines
    • H05B6/707—Feed lines using waveguides
    • 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
    • H05B6/74—Mode transformers or mode stirrers
    • H05B6/745—Rotatable stirrers

Definitions

  • the invention relates to a microwave oven according to the preamble of the main claim and a method for operating a microwave oven according to the preamble of claim 4.
  • the microwaves generated by a magnetron are fed into a cooking chamber which acts as a resonance chamber and is enclosed by the metallic walls of the cooking muffle. It is possible to feed the magnetron output probe directly into the cooking space.
  • a cooking chamber which acts as a resonance chamber and is enclosed by the metallic walls of the cooking muffle. It is possible to feed the magnetron output probe directly into the cooking space.
  • rotary antennas which move the microwave field relative to the food to be cooked at rest.
  • the direct feeding of the milk waves into the cooking space causes great difficulties for the magnetron to adapt to different loading of the cooking space, such a construction is very complex. Because of the different resonance structure of the cooking chamber, there is also an uneven heating.
  • a microwave oven for uniform heating of food which has a microwave generator and an elongated waveguide leading to the cooking space.
  • the waveguide is closed at its end facing away from the microwave generator with a rear wall arranged perpendicular to a coupling opening between the waveguide and the cooking space.
  • a rotating body is arranged in the waveguide.
  • a microwave oven which is also provided with a rotating body in the waveguide.
  • the rotating body consists of a pin and a rectangular loop attached to the pin. Due to this special design of the rotating body, the phases of the incident wave and the wave reflected from the rear wall are shifted against each other.
  • the object of the present invention is to improve a microwave oven of the type mentioned and a method such that a simple and effective coupling of the microwaves into the cooking space is achieved and at the same time the material to be heated can be homogeneously heated due to a uniform field distribution.
  • the microwave oven according to the invention is designed in the manner characterized in the main claim.
  • the method for solving the problem is characterized in claim 4.
  • the undesired change in the load impedance of the magnetron with different loading conditions is used to bring about a change in the frequency of the magnetron and thereby achieve a uniform heating of the food.
  • the periodic change in the wave resistance results in a periodic change in the output frequency of the magnetron and this change in frequency causes the excitation of different forms of resonance in the cooking chamber serving as a resonator.
  • the superimposition of different forms of resonance leads to an overall uniform heating result.
  • the waveguide 3 is arranged between the magentron 1 generating the microwaves and the cooking chamber 2.
  • the rotating body 5 In front of the rear wall 4 of the end of the waveguide 3 facing away from the magnetron, the rotating body 5 is arranged, which consists of a plate running parallel to the rear wall and rotatable about its central longitudinal axis.
  • the plate is made of an electrically conductive or dielectric material.
  • the wave resistance of the magnetron 1 through the waveguide 3 via the coupling opening 6 into the cooking space can be changed periodically by the rotating body 5. This change in the input resistance of the furnace affects the magnetron 1 by periodically changing its output frequency.
  • the change at an output frequency of 2.450 GHz can be up to ⁇ 10 MHz, which results in a superposition of different resonance forms. This leads to an even heating of the food.
  • the effect of the device according to the invention is not based on the deflection of the microwaves by a complicated "wave stirrer", but on the "change in length" of the waveguide, which couples the microwaves into the cooking space. This is done using a simple sheet metal part. While the waveguide is shortened in the position of the plate of the rotating body shown, this plate is practically ineffective in the dashed position. When the plate rotates in the direction of the arrow, the wave resistance changes constantly and periodically.
  • the coupling opening 6 is covered in a known manner by a wall 7 which is permeable to microwaves and which prevents harmful influences from the cooking chamber from acting on the magnetron.
  • a wall 7 which is permeable to microwaves and which prevents harmful influences from the cooking chamber from acting on the magnetron.
  • High-temperature resistant dielectric materials such as ceramics or borosilicate glass are common for this.
  • the rotating body 5 has a good effect if it is located at a distance between ⁇ / 4 and ⁇ / 2 from the rear wall 4 and above the coupling opening 6. Good results are achieved in particular if the rotating body 5 is arranged at a distance of 3 ⁇ 8 ⁇ from the rear wall.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Constitution Of High-Frequency Heating (AREA)
  • Electric Ovens (AREA)
  • General Preparation And Processing Of Foods (AREA)

Claims (4)

  1. Four à micro-ondes, pour homogénéiser l'échauffement d'aliments avec un guide d'ondes (3) allongé, menant du générateur à micro-ondes (1) à l'enceinte de cuisson (2) et raccordé, à son extrémité opposée au générateur à micro-ondes (1), à une paroi arrière (4), disposée perpendiculairement à une ouverture de couplage (4) entre le guide d'ondes (3) et l'enceinte de cuisson (2), un corps tournant (5) à déplacement périodique étant disposé dans le guide d'ondes (3), caractérisé en ce que le corps tournant (5) est composé d'un plateau tournant, fabriqué en un matériau conducteur de l'électricité ou en un matériau diélectrique, en ce que le corps tournant (5) est espacé de la paroi arrière (4) à une distance lambda/4 à lambda/2 et masque celle-ci de façon variable, du fait de son mouvement rotatif et en ce que l'ouverture de couplage (6) se trouve au-dessous du corps tournant (5).
  2. Four à micro-ondes selon la revendication 1, caractérisé en ce que le plateau est susceptible de tourner autour de son axe horizontal.
  3. Four à micro-ondes selon l'une des revendications 1 ou 2, caractérisé en ce que le corps tournant est espacé de la paroi arrière (4) à une distance de 3 x lambda/8.
  4. Procédé de fonctionnement d'un four à micro-ondes, pour homogénéiser l'échauffement d'aliments, les micro-ondes produites par un générateur à micro-ondes (1) étant guidées vers l'enceinte de cuisson (2), par l'intermédiaire d'un guide d'ondes (3) allongé, délimité par son extrémité, opposée au générateur à micro-ondes (1), à l'aide d'une paroi arrière (4), disposée perpendiculairement à une ouverture de couplage (6), entre le guide d'ondes (3) et l'enceinte de cuisson (2) et la résistance aux ondes guidées vers l'enceinte de cuisson (2) au moyen du guide d'ondes (3) étant modifiée au moyen d'un corps tournant (5) à déplacement périodique, disposé dans le guide d'ondes (3), caractérisé en ce que les micro-ondes sont couplées dans l'enceinte de cuisson (2), directement ou indirectement, par l'ouverture de couplage (6) se trouvant audessous du corps tournant (5), par ce corps tournant (5), composé d'un plateau tournant fabriqué en un matériau diélectrique ou conducteur de l'électricité, et en ce que le corps tournant, espacé de la paroi arrière (4) à une distance de lambda/4 à lambda/2, masque de façon variable la paroi arrière (4) lors de son déplacement en rotation.
EP87118985A 1987-02-03 1987-12-21 Procédé et dispositif pour homogénéiser l'échauffement d'aliments dans un appareil de cuisson chauffant à micro-ondes Expired - Lifetime EP0277342B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT87118985T ATE91375T1 (de) 1987-02-03 1987-12-21 Verfahren u. vorrichtung zur vergleichmaessigung der erwaermung von speisen in einem mit mikrowellenenergie beheizten gargeraet.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3703133 1987-02-03
DE19873703133 DE3703133A1 (de) 1987-02-03 1987-02-03 Verfahren und vorrichtung zur vergleichmaessigung der erwaermung von speisen in einem mit mikrowellenenergie beheizten gargeraet

Publications (3)

Publication Number Publication Date
EP0277342A2 EP0277342A2 (fr) 1988-08-10
EP0277342A3 EP0277342A3 (en) 1988-08-31
EP0277342B1 true EP0277342B1 (fr) 1993-07-07

Family

ID=6320098

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87118985A Expired - Lifetime EP0277342B1 (fr) 1987-02-03 1987-12-21 Procédé et dispositif pour homogénéiser l'échauffement d'aliments dans un appareil de cuisson chauffant à micro-ondes

Country Status (3)

Country Link
EP (1) EP0277342B1 (fr)
AT (1) ATE91375T1 (fr)
DE (2) DE3703133A1 (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3818490A1 (de) * 1988-05-31 1989-12-07 Bosch Siemens Hausgeraete Mikrowellen-haushaltgeraet
DE3843039A1 (de) * 1988-12-21 1990-06-28 Bosch Siemens Hausgeraete Haushaltgeraet
US6114677A (en) * 1996-06-03 2000-09-05 Matsushita Electric Industrial Co., Ltd. Microwave heating apparatus having a metal plate rotatably disposed in a wave guide
EP2187702A1 (fr) * 2008-11-17 2010-05-19 Topinox Sarl Appareil de cuisson doté d'un chauffage à micro-ondes

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2761942A (en) * 1952-06-06 1956-09-04 Raytheon Mfg Co Heating apparatus
GB752206A (en) * 1953-11-12 1956-07-04 Raytheon Mfg Co Improvements in or relating to high frequency dielectric heating apparatus
FR1208182A (fr) * 1957-12-10 1960-02-22 Miwag Mikrowellen A G Dispositif pour engendrer une distribution primaire définie de champ dans une cavité en vue de chauffer des substances organiques au moyen d'hyperfréquences
CH393577A (de) * 1961-12-13 1965-06-15 Patelhold Patentverwertung Vorrichtung zum dielektrischen Erwärmen von Stoffen
US3521019A (en) * 1968-02-19 1970-07-21 Varian Associates Microwave heating cavity with a venetian blind mode stirrer
SE345903B (fr) * 1970-12-21 1972-06-12 Philips Svenska Ab
US4301347A (en) * 1980-08-14 1981-11-17 General Electric Company Feed system for microwave oven
US4336434A (en) * 1980-08-15 1982-06-22 General Electric Company Microwave oven cavity excitation system employing circularly polarized beam steering for uniformity of energy distribution and improved impedance matching

Also Published As

Publication number Publication date
EP0277342A3 (en) 1988-08-31
DE3703133A1 (de) 1988-08-11
DE3786451D1 (de) 1993-08-12
EP0277342A2 (fr) 1988-08-10
ATE91375T1 (de) 1993-07-15

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