EP2187702A1 - Cooking device with microwave heating - Google Patents

Abstract

The device has a side wall part with an opening, and cooking and pressure chambers accommodating cooking goods. An antenna (50) emits microwaves in the cooking chamber. A cover (41) is made of microwaves permeable material and covers the opening to protect the antenna from atmosphere in the cooking chamber such that the microwaves arrive in the cooking chamber through the cover. The wall part is incorporated by a rear wall, a cover, base surface and side walls that limit the cooking chamber. The cover extends parallel to the wall part over a part of a surface defined by the wall part.

Description

The invention relates to a cooking appliance, comprising: an interior, which comprises at least one cooking chamber for receiving food, at least one wall or wall part with at least one opening, at least one antenna for emitting microwaves in the interior and a cover of a substantially for Microwave-permeable material that covers the opening to protect the antenna from the atmosphere in the interior, wherein the microwaves pass through the cover into the interior and the wall or the wall part is covered by the wall bounding the interior space.

From the DE 197 09 642 A1 is a low-pressure plasma microwave feed for plasma heating with a microwave tube including antenna and a piston arranged above the antenna in a plasma chamber known. The piston covers only the antenna, while magnets in the area of a wall opening for the antenna and the piston keep plasma away from this wall area.

A generic cooking appliance is from the EP 1 241 923 A1 known. The known cooking appliance comprises a microwave generator which feeds microwaves into a waveguide. A receiving antenna is disposed in the microwave conductor so as to receive a portion of the energy propagating in the waveguide. A transmitting antenna of the microwave guide is disposed in an installation room to radiate microwaves. The transmitting antenna is separated from a cooking chamber by a microwave transparent Shield, such as a parallel to the bottom surface of the cooking chamber arranged glass plate, separated. A disadvantage of this known cooking appliance is the fact that the space available in the cooking appliance is not used efficiently.

The invention is therefore based on the object to further develop the generic cooking appliance such that the disadvantages of the prior art are overcome. In particular, the cooking appliance, preferably a suitable for the kitchen use cooking appliance, should be made more compact.

This object is achieved in that the cover extends parallel to the wall or the wall part over only a portion of the surface defined by the wall or the wall part.

The cover can define a space delimited from the interior of the cooking appliance within the wall of the interior and / or have a flange extending substantially parallel to the wall or the wall part.

Furthermore, it can be provided that the antenna comprises at least one electrical conductor extending through the opening, wherein preferably a space and / or at least one support for guiding the antenna is or are located between the at least one electrical conductor and the cover.

Furthermore, it is proposed that the opening is round, in particular circular, and / or is provided in a side wall, preferably in a first side wall part, of the interior.

It is proposed with the invention that the first side wall part, in particular with an obtuse angle, on a second side wall portion, on which preferably a fan is rotatably mounted, is mounted.

It is preferably proposed that a flow-guiding element is arranged in the interior, which at least partially divides the interior space into a cooking space and a pressure space, wherein in the pressure chamber, a fan wheel is arranged, the flow guide is provided with at least one opening, in particular a centrally located opening for sucking atmosphere from the cooking chamber into the pressure chamber, and the Strömungsleitglied between the pressure chamber and the cooking chamber, in particular at the edge region of the Strömungsleitglieds , at least one compound for blowing atmosphere from the pressure chamber in the oven leaves.

Furthermore, it can be provided that the side wall part to the fan and / or to a point in the interior, in particular in the oven, is aligned or aligned.

Embodiments of the invention are also characterized by at least one microwave guide structure that guides microwaves from at least one microwave generator to at least the opening, wherein preferably the microwave guide structure comprises a section that extends to the opening, preferably with a cross-section parallel to the propagation direction of the Seen microwaves round, in particular circular, outer circumference.

Embodiments of the invention may also be characterized by a plurality of openings, of which at least two are arranged at different heights in the cooking appliance, and each at least one antenna for emitting microwaves leads into the interior, wherein in particular the antennas each with at least one magnetron, preferably with a respective rated power of up to 2000 W HF, in connection.

Furthermore, at least one further device for the treatment of food to be cooked in the oven, in particular at least one device from the group comprising: an electric heater, a gas-powered heater, a heat exchange device, a cooling device, a moisture supply, a moisture removal, a ventilation device and a venting device may be provided ,

An embodiment of the invention may include at least one sensing device, a display device, an operating device and a control or regulating device comprise, wherein the control or regulating device is preferably operatively connected to at least one microwave source, at least one further treatment device, the display device, the operating device and / or the sensing device.

The invention is thus based on the surprising finding that each antenna protrudes into the interior of a cooking appliance, so an additional installation space for the antenna (s) is eliminated, so that the interior can be made larger. Therefore, a larger cooking space can be provided for more food. Also, other treatment facilities, in particular in the pressure chamber, which can also be increased, are arranged. In particular, other devices may also be arranged on the same inner wall to which each antenna is already attached, such as e.g. a ventilation device, a heater and a steam generator in the case of a Kombinationsgargeräts. The fact that a cover is arranged over each antenna, only a seal at the edge of the respective cover is made. A difficult sealing of an opening in a cover through which e.g. could project a rod antenna, so it is not required.

Since each cover can define a space delimited from the interior of the cooking appliance, a medium such as air can be provided to improve the thermal insulation in this delimited space. The medium can be chosen so that the microwaves can propagate through the medium with less energy loss than would be the case if the cover were simply made thicker. In addition, a rod antenna can be arranged in at least part of the delimited space.

If the antenna comprises at least one electrical conductor extending through the opening, microwaves emitted transversely to the longitudinal axis of the conductor can enter the interior without reflections. In particular, so the microwave energy can be radiated to the same extent in all directions.

Located between the at least one electrical conductor and the cover a gap, the electrical conductor is thermally better isolated from the interior.

If the cooking appliance comprises a support extending between the cover and the electrical conductor for guiding the antenna, the radiation characteristic can not easily be impaired by impacts during the transport of the cooking appliance. Also, the cooking appliance can be used, for example, on ships or trains without affecting its operation.

If the cover has a flange running substantially parallel to the wall or the wall part with the opening to be covered for the antenna, this makes it easier to seal the opening sufficiently against the interior space. It can be used flat gaskets. Furthermore, the sealing surface is relatively large.

If the opening is round, in particular circular, this simplifies the sealing of the opening. For a given dimension of the aperture caused by the antenna, the perimeter of the aperture is greatest at a circular, in particular a circular, aperture.

If the opening is provided in a side wall or a side wall part of the interior, less stringent requirements are placed on the seal of the opening to the interior than would be the case with an arrangement in the bottom area of the interior. In the latter area, liquid and cooking residues accumulate, in particular in cooking appliances for large-scale kitchen use. Another advantage is that the height of the cooking appliance can be kept relatively small, so that certain embodiments can also be stackable without affecting the operability, since the opening is then not located in the ceiling.

If the opening is provided in a first side wall part, which adjoins a second side wall part, and a fan wheel is rotatably mounted on the second side wall part, the microwaves emitted by the antenna will propagate, in particular if the first side wall part is at an angle to the second side wall part, in the direction of the fan in the interior. You are doing off the fan, which is generally off a microwave reflective material is made, swirled. The existing already for loading and / or ventilation fan thus gets an additional function. A separate mode mixer is not required, at least in the area of the interior where the fan is located.

If the cooking appliance comprises at least one microwave conducting structure which guides microwaves from at least one microwave generator to at least the opening, cooling of the microwave generator is easier, in particular in the case where further heating of the cooking space, such as by an electric or gas-powered heating device, is available. The microwave generator can be positioned at a greater distance of the cooking chamber. In general, then there is a greater freedom in the division of existing space in the cooking space.

If the microwave conducting structure comprises a section which extends as far as the opening and has a round, in particular circular, outer circumference seen in cross section parallel to the wall or the wall part, a relatively small thermal bridge is provided between the microwave conducting structure and the wall of the inner space. Thus, heat conduction in the direction of the microwave generator is restricted as much as possible. In addition, with a round cross-sectional shape, the effect of thermal stresses is lower.

In the case in which the interior comprises a flow-guiding member which at least partially divides the interior space into a cooking space and a pressure space, a fan wheel is arranged in the pressure space, providing the flow-guiding element with at least one, in particular central, opening for drawing in air from the cooking space is and the flow guide between the pressure chamber and the cooking chamber, in particular at the edge region of the Strömungsleitglieds, at least one air-permeable compound leaves free, form the pressure chamber and the cooking chamber two coupled resonators for the microwaves. Therefore, it is irrelevant in which of the two subspaces of the interior, the microwaves are radiated first. In addition, the circulation of the cooking chamber in the interior ensures a further homogenization of the temperature. To further influence the cooking chamber climate, a moisture supply device such as Steam injection device may be provided, which injects steam into the air flow, or an electric heater or a gas heater for heating the air. Especially in cooking appliances for the commercial kitchen use, the homogenization of the cooking chamber climate, which comes about by the circulation of the cooking chamber, is advantageous.

If the cooking appliance a plurality of openings, at least two of which are arranged at different heights in the cooking appliance, and each at least one antenna for emitting microwaves into the interior, wherein the radiated from each antenna microwaves pass through the respective opening in the interior, and the antennas are in each case connected to at least one magnetron, in particular with a rated power of 2000 W HF or less, then in the cooking appliance according to the invention, even with a large interior space, the microwave energy distribution is better than would be the case if the microwaves were replaced by a microwave single opening would enter the interior. When using a plurality of magnetrons with a respective rated power of a maximum of 2000 W HF can be used on magnetrons for Mikrowellengargeräte for private use, which are produced inexpensively in mass production. Thus, commercially available components can also be used in cooking appliances for large-scale kitchen use. At the same time a good microwave energy distribution is realized.

If the cooking appliance comprises a further device for the treatment of food in the cooking chamber, the food can be subjected to a combined treatment without having to remove it from the cooking appliance.

If the cooking appliance comprises at least one sensing device and a control or regulating device, in particular a control and regulating device, which is in operative connection with at least one microwave source and optionally the further treatment device, food can be subjected to a complicated combination treatment, without requiring human intervention or human supervision is mandatory.

Figur 1

eine Längsschnittansicht eines Teils eines ersten erfindungsgemäßen Gargeräts von vorne;

Figur 2

eine Querschnittansicht eines Teils des Gargeräts von Figur 1 von oben;

Figur 3

eine perspektivische Ansicht einer Mikrowellenleitstruktur mit einem Element zum Abstrahlen von Mikrowellen in den Innenraum des Gargeräts der Figur 1 und 2 und mit einer das Element umgebenden Haube;

Figur 4

eine Hinteransicht der Mikrowellenleitstruktur von Figur 3;

Figur 5

eine stirnseitige Ansicht der Mikrowellenleitstruktur der Figuren 3 und 4;

Figur 6

eine Seitenansicht der Mikrowellenleitstruktur der Figur 3 bis 5;

Figur 7

eine Längsschnittansicht der Mikrowellenleitstruktur der Figur 3 bis 6;

Figur 8

eine Längsschnittansicht eines zweiten erfindungsgemäßen Gargeräts;

Figur 9

einen Querschnitt in Draufsicht des zweiten Gargeräts von Figur 8;

Figur 10

eine schematische Querschnittansicht eines handelsüblichen Magnetrons; und

Figur 11

eine Detailansicht der Anordnung einer Mikrowellenquelle an der Wand des zweiten Gargeräts der Figur 8 und 9.

Further features and advantages of the invention will become apparent from the following detailed description of some embodiments of the invention with reference to schematic drawings. Showing:

FIG. 1

a longitudinal sectional view of a portion of a first cooking appliance according to the invention from the front;

FIG. 2

a cross-sectional view of a portion of the cooking appliance of FIG. 1 from above;

FIG. 3

a perspective view of a Mikrowellenleitstruktur with an element for emitting microwaves in the interior of the cooking appliance of FIGS. 1 and 2 and with a hood surrounding the element;

FIG. 4

a rear view of the microwave guide structure of FIG. 3 ;

FIG. 5

an end view of the Mikrowellenleitstruktur the FIGS. 3 and 4 ;

FIG. 6

a side view of the microwave guide structure of FIGS. 3 to 5 ;

FIG. 7

a longitudinal sectional view of the microwave guide structure of FIGS. 3 to 6 ;

FIG. 8

a longitudinal sectional view of a second cooking appliance according to the invention;

FIG. 9

a cross-section in plan view of the second cooking appliance of FIG. 8 ;

FIG. 10

a schematic cross-sectional view of a commercially available magnetron; and

FIG. 11

a detailed view of the arrangement of a microwave source on the wall of the second cooking appliance of FIGS. 8 and 9 ,

One in the Figures 1 and 2 exemplified first inventive cooking appliance 1 comprises a of a rear wall 2, a ceiling 3, a bottom surface 4, a first side wall 5, a front wall 6, a second side wall 7 and a side wall part 8 limited interior, the rear wall 2 and the front wall 6 also can be referred to as sidewalls. The interior is at least partially subdivided by a flow-guiding element 9 into a cooking chamber 10 and a pressure chamber 11. In the front wall 6 is a door not shown for loading the cooking chamber 10 with food (not shown) and removal thereof.

In the cooking chamber 10, a frame 12 with a plurality of rails 13a-f for insertion of food supports (not shown), on which the food is placed, is provided.

In the pressure chamber 11 is a radial fan 14, which is driven by a motor 16 via a shaft 15. The radial fan 14 sucks in air, steam and vapor from the cooking chamber 10 through an opening 17 located in the central region of the flow-guiding element 9 and blows it off radially. Thus, there is a pressure difference between the pressure chamber 11 and the cooking chamber 10. The sucked gases return due to this pressure difference in the cooking chamber 10, through slots 18 between the edge of the Strömungsleitglieds 9 and the ceiling 3 and optionally the bottom surface 4. In addition or As an alternative to the slots 18, openings in the flow-guiding member 9 may also be provided in the edge region of the flow-guiding member 9.

The illustrated cooking appliance 1 comprises a microwave heating device and a further device for treating the food in the cooking chamber 10, such as a (not shown) ventilation device. In addition, for example, an electric heater, a gas-operated heater, a heat exchange device, a cooling device, a moisture supply device and / or a moisture removal device may be provided. The electric or gas-operated heating device or the heat exchange device can completely or partially surround the fan wheel 14 for heating the conveyed air. For example, the moisture supply device may include a steam injection device that injects steam into the airflow of the radial fan 14. The moisture removal device is preferably located in a bottom region 19.

At least the regulation or control and the electrical connection of each treatment device, as well as the motor 16, are located in an installation space 20 next to the pressure space 11. In the illustrated example, the installation space 20 is directly via a door (not shown) in an outer side wall 21 accessible, namely from outside the cooking appliance 1, to make maintenance and installation easier.

The microwave heating comprises two magnetrons 22, 23, which generate microwaves, which are fed into the interior in each case via a waveguide structure 24, 25. In the in the Figures 1 and 2 As shown, the microwaves are radiated into the pressure chamber 11. The pressure chamber 11 and the cooking chamber 10 form coupled, substantially cuboid, resonators. For this reason also finds an even distribution the radiated microwave energy in the cooking chamber 10 in the pressure chamber 11. The coupling takes place essentially via the slots 18, which are also provided for circulating the cooking chamber atmosphere. In addition, in the flow guide 9 (not shown) may be provided for microwave-permeable openings. In order to maintain the pressure difference between the pressure chamber 11 and the cooking chamber 10, such additional openings are generally not permeable to air, but filled with dielectric material, such as quartz glass, borosilicate glass or ceramic.

The radial fan 14 is at least partially made of a material that reflects microwaves. The microwaves are emitted via gates 26, 27 into the pressure chamber 11. These doors 26,27 are located in the side wall portion 8, which adjacent the side wall 7 through which the drive shaft 15 of the radial fan 14 projects, is arranged. The radial fan 14 extends, relative to the drive shaft 15 in the radial direction to a maximum of the transition from the side wall 7 to the side wall portion 8, so that the gates 26,27 are not shielded by the fan 14. It is explained below that are provided for the emission of microwaves elements in the form of antennas. The radiation characteristic of the antennas is such that at least one emission takes place parallel to the side wall part 8. The thus radiated microwaves therefore reach the radial fan 14 and are swirled by it, which leads to a homogenization by mode mixing and supports the distribution of microwaves in the cooking chamber 10.

Even if the cooking appliance 1 is designed for large kitchen use, commercially available magnetrons 22, 23, which are designed for use in household microwave appliances, are used for reasons of cost. These have a nominal power of about 2000 W HF. In order nevertheless to achieve a sufficient heating of the food, the number of magnetrons 22, 23 and Mikrowellenleitstrukturen 24 depending on the number of rails 13a-f in the frame 12, ie the number and dimensions of the recordable food supports, determined. In order to realize an even more uniform microwave energy distribution, the gates 26, 27 are provided at different heights. For this reason, in the example shown, a waveguide structure 24, 25 is assigned a respective magnetron 22, 23. In an alternative However, it could be several embodiments, eg two microwave generators per waveguide structure 24, 25 at two ports 26, 27.

The use of the microwave guide structures 24, 25 makes it possible to keep the side wall part 8 relatively small, since the magnetrons 22, 23 do not necessarily have to be arranged directly behind it in the installation space 20. This in turn allows the use of a larger radial fan 14 and / or a further heating or heat exchange device surrounding the radial fan 14.

In the cooking chamber 10 of the cooking appliance 1, which is designed for large kitchen use, sometimes extreme conditions prevail. In particular, the humidity may be high and the temperature may reach levels of about 400 ° C. The installation space 20 and the components located therein, in particular the magnetrons 22, 23, should be protected from this atmosphere.

A microwave guide structure 28 which can be used as a microwave guide structure 24 or 25 is shown in FIGS Figures 3-7 shown. It comprises a first section comprising a rectangular waveguide 29 and a second section 30, which in this embodiment comprises a first part 31 with a cylindrical, circular outer wall and a coupling 32. The diameter of said circular portion is smaller than the distance between each two parallel walls of the rectangular waveguide 29. The outer wall of the coupling 32 has on the inside and on the outside at least in the region of an opening in the side wall part 8 Figures 1 and 2 ) has a circular cross section. The connection from the first part 31 of the second section 30 to the rectangular waveguide 29 is realized by means of a threaded bush 33, see FIG. 7 ,

In a substantially flat wall 34 of the rectangular waveguide 29 is an opening 35 with attachment means, e.g. in the form of a thread 36 for screwing on a magnetron 22,23. After being screwed through the opening 35, the magnetron antenna protrudes into the rectangular waveguide 29, which acts as a resonator space.

The second section 30 of the microwave guide structure 28 comprises a circular waveguide with an inner conductor 37, that is to say a coaxial conductor. The inner conductor 37 extends into the Rectangular waveguide 29, as in the FIG. 7 you can see. He is bent there by about 90 ° to be attached at a first end 38 to a wall 39 of the rectangular waveguide 29 by means of a screw 40 can.

In the area of the coupling 32, a hood 41 made of dielectric material is located to seal off the cooking chamber atmosphere. The material should also have a low thermal conductivity so that materials such as glass, e.g. Quartz glass or borosilicate glass (pyrex), or steatite. Glass has the advantage of lower dielectric constant over ceramic materials.

Although a further sealing in the region between the inner conductor 37 and the inner wall of the coupling 32, or the first part 31 of the second portion 30 can be made, for example. By another dielectric washer, not shown, eliminating in principle the need for this. Above all, because of the different coefficients of expansion of the material of the coupling on the one hand and the material of the dielectric sealing disc on the other hand, the use of the latter is undesirable.

The hood 41 is supported on the coupling 32 via a flange 42 and a flat gasket 43. In an alternative embodiment, it could be supported in a similar manner on the wall part 8 of the cooking appliance 1. The hood 41 is pressed with a union nut 44 against the coupling 32 at the end of the second portion 30 of the Mikrowellenleitstruktur 28 and sealed by a second flat seal 45 against the cooking chamber atmosphere.

The coupling 32 connects the Mikrowellenleitstruktur 28 with the side wall portion 8 of the interior of the cooking appliance 1, which in the Figures 1 and 2 is shown. For this purpose, the coupling 32 is inserted during assembly through a round opening (not shown) in the side wall part 8. The coupling 32 is supported on a flange 46 on the outer wall of the side wall portion 8 from. On the inside of the side wall part 8 engages a flat gasket 47. A second union nut 48 ensures a gas-tight seal of the installation space 20 with respect to the pressure chamber 11.

In the in the Figures 3-7 In the illustrated embodiment, the inner conductor 37 merges at a second end 49 into an antenna 50 for emitting the microwaves into the pressure chamber 11 of the cooking appliance 1. In this case, the antenna 50 is thus formed by the end 49 of the inner conductor 37. There are therefore few components, and it is a jump avoided. In an alternative, not shown embodiment, means for releasably securing a separate antenna are provided at the end of the inner conductor 37. In that case, the radiation characteristic can be freely selected by selecting an antenna having a certain shape. The depicted antenna 50 is a fixedly positioned rod antenna, eg a λ / 4 or λ / 2 dipole antenna. In an alternative embodiment, the antenna 50 may have a shape other than that shown. In particular, a fixedly positioned circularly polarized antenna, such as a helical antenna, may be used.

In the in the Figures 3-7 In the embodiment shown, the inner conductor 37 is centered in the second section 30 of the microwave guide structure 28 by means of a disk 51 of dielectric material, eg quartz glass or steatite. The position and thickness of the disc 51 can also be used to adapt the impedance of the second section 30 to that of the rectangular waveguide 29. In addition, there is at least one support 52 for guiding the antenna 50 in the hood 41. It can also be provided, only the support 52, so without the disc 51, to install.

In the FIGS. 8 and 9 a second cooking appliance 53 according to the invention is shown which, like the first cooking appliance 1 of the FIGS. 1 and 2 a defined by a rear wall 54, a ceiling 55, a bottom surface 56, a first side wall 57, a front wall 58, a second side wall 59 and a side wall portion 60 interior. Also in this case, the interior of a flow guide 61 is at least partially divided into a cooking chamber 62 and a pressure chamber 63 and is in the cooking chamber 62, a frame 64 with a plurality of rails 65a-f for inserting food supports (not shown), to the Gargut (not shown) can be placed, provided.

In the pressure chamber 63 is a radial fan 66 which is driven by a motor 68 via a shaft 67. The motor 68 is located in an arranged next to the pressure chamber 63 installation space 69th The radial fan 66 sucks atmosphere from the Cooking chamber 62 by an opening located in the central region of the Strömungsleitglieds 61 70 and blows it off radially.

The cooking appliance 53 shown comprises a microwave heating and a further device for the treatment of food in the cooking chamber 62, as well as in connection with the Figures 1 and 2 described cooking appliance 1.

In contrast to that in connection with the Figures 1 and 2 described cooking appliance 1 are in the in the FIGS. 8 and 9 Cooking device 53 shown radiated in magnetrons 71,72 microwaves through a respective port 73,74 on a direct path in the pressure chamber 63.

The pressure chamber 63 and the cooking chamber 62 form again coupled, essentially cuboid resonators. For this reason, there is also a uniform distribution of the microwave energy in the cooking chamber 62 via the feed of the same into the pressure chamber 69. The coupling is again essentially via slots 75 between the flow guide 61 and the walls 58,54,55,56 of the interior, which are also provided for circulating the cooking chamber atmosphere.

The radial fan 66 extends in the radial direction at most to the transition from the side wall 59 to the side wall portion 60, so that the gates 73,74 are not shielded by the fan 66. For the radiation in the pressure chamber 69 rod or slot antennas are provided, of which an antenna stub 77 is shown. The radiation characteristic is such that at least one emission takes place parallel to the side wall part 60. The thus radiated microwaves therefore reach the radial fan 66 and are swirled by him. To even out the microwave energy and transfer the microwave energy into the cooking chamber 62 also contributes that the side wall portion 60 is at an angle to the side wall 59. Due to this arrangement, the microwaves are already partly reflected into the cooking chamber 62 via the rear wall 54.

To clarify some terms used here is in the FIG. 10 exemplified the magnetron 71 with known per se interpretation. The magnetron 71 includes a Housing 76 from which protrudes the antenna stub 77, and a cathode 78 which is heated during operation. The cathode 78 is surrounded by an anode 79 with protruding wings 80. The magnetron 71 further comprises a magnet stack 81. During operation, the electrons emitted by the cathode 78 are conducted around the cathode 78 under the influence of the electric and magnetic fields. The action of the electric and magnetic fields on the electrons incident on the anode 79 produces an oscillation. An inner conductor 82 of the antenna couples the generated microwaves out of the oscillator device formed by the cathode 78 and anode 79 with vanes 80 and radiates them via the antenna stub 77 into the pressure chamber 63. The inner conductor 82 is surrounded by a protective cap 83. The microwaves generated in the magnetron 71 are thus radiated directly into the pressure chamber 63, without the interposition of a waveguide. It should be noted that some magnetrons instead of an inner conductor 82 comprise a waveguide for coupling out the microwaves.

The magnetrons 71, 72 are attached to the outside of the side wall part 60. To protect them from the cooking atmosphere, is, as from the FIG. 11 can be seen, a hood 84 used. The hood 84 is made of a dielectric material that is permeable to microwaves. The description of the hood 41 of the first embodiment of the cooking appliance 1 also applies to the hood 84 from the FIG. 11 to.

This hood 84 surrounds the antenna stub 77 of the magnetron 71 projecting through an opening in the side wall part 60. To increase the thermal insulation, there is a gap 85 between the inside of the hood 84 and the antenna stub 77. The gap 85 is filled with air.

To account for the different coefficients of thermal expansion of the hood 84 and the sidewall member 60, the hood 84 is secured to the sidewall member 60 via a flange 86 in the illustrated embodiment. Thus, the hood 84 fulfills the dual function of a gas-tight seal towards the pressure chamber 63 as well as a thermal insulation of the magnetron antenna stub 77. The flange connection further comprises two flat gaskets 87,88, a stainless steel rotary member 89 and screws 90,91 for fixing the stainless steel rotary member 89 on the cooking chamber side of the side wall portion 60th

The direct magnetron coupling, as shown above and in the Figures 8-11 is shown, has the advantage that the usual in professional cooking appliances Modenmischerboxen and paddle wheels omitted outside the cooking appliance interior. This also applies to waveguides, circulators and directional couplers that are required to protect a magnetron from mismatch, which are commonly used. Both costs and space in the installation room 69 are saved.

The features of the invention disclosed in the foregoing description, in the claims and in the drawings may be essential both individually and in any combination for the realization of the invention in its various embodiments.

LIST OF REFERENCE NUMBERS

1

Cooking appliance

2

rear wall

3

blanket

4

floor area

5

Side wall

6

front wall

7

Side wall

8th

Sidewall portion

9

flow directing

10

oven

11

pressure chamber

12

frame

13a-f

rail

14

radial fan

15

wave

16

engine

17

opening

18

slot

19

floor area

20

installation space

21

Side wall of the cooking appliance

22

1. Magnetron

23

2. Magnetron

24

1. microwave conducting structure

25

2. microwave guide structure

26

1st door

27

2nd door

28

Mikrowellenleitstruktur

29

Rectangular waveguide

30

2nd section

31

Part 1 of Section 2

32

clutch

33

threaded bushing

34

Wall of the rectangular waveguide

35

Opening in the wall

36

Thread on the opening

37

inner conductor

38

1. end of the inner conductor

39

Wall of the rectangular waveguide

40

screw

41

Hood

42

Flange of the hood

43

gasket

44

Nut

45

gasket

46

flange

47

gasket

48

Nut

49

2. end of the inner conductor

50

antenna

51

disc

52

support

53

Cooking appliance

54

rear wall

55

blanket

56

floor area

57

Side wall

58

front wall

59

Side wall

60

Sidewall portion

61

flow directing

62

oven

63

pressure chamber

64

frame

65a-f

rail

66

radial fan

67

wave

68

engine

69

installation space

70

opening

71

magnetron

72

magnetron

73

gate

74

gate

75

slots

76

magnetron body

77

antenna stub

78

cathode

79

anode

80

wing

81

magnetic stack

82

inner conductor

83

protective cap

84

Hood

85

gap

86

flange

87

gasket

88

gasket

89

Stainless steel swivel

90

screw

91

screw

Claims (11)

Cooking appliance (1; 53) comprising: an interior space (10, 11; 62, 63), which comprises at least one cooking space (10; 62) for receiving food to be cooked, at least one wall or wall part (8; 60) having at least one opening, at least one antenna (50; 77) for emitting microwaves into the interior space (10,11; 62,63) and a cover (41; 84) of substantially microwave transparent material covering the opening to protect the antenna (50; 77) from the atmosphere in the internal space (10,11; 62,63) the microwaves pass through the cover (41, 84) into the interior space (10, 11; 62, 63) and the wall or wall part (8, 60) of the wall (10, 11; 2-8, 53-60), characterized in that the cover (41; 84) extends parallel to the wall or wall portion (8; 60) over only a portion of the area defined by the wall or wall portion (8; 60). Cooking appliance according to claim 1, characterized in that
the cover (41; 84) defines a space within the wall (2 -8; 53-60) of the interior (10,11; 62,63) defined by the interior (10,11; 62,63) of the cooking appliance (1; 53) ) and / or has a substantially parallel to the wall or the wall part (8; 60) extending flange (42; 86). Cooking appliance according to claim 1 or 2, characterized in that
the antenna (50; 77) comprises at least one electrical conductor extending through the opening, preferably a gap (85) and / or at least one support (52) between the at least one electrical conductor and the cover (41; 84) Guide the antenna (50; 77) located or located. Cooking appliance according to one of the preceding claims, characterized in that the opening is round, in particular circular, and / or in a side wall (8; 60), preferably in a first side wall part (8; 60) of the interior (10,11; 62 , 63) is provided. Cooking appliance according to claim 4, characterized in that
the first side wall part (8; 60) is mounted, in particular at an obtuse angle, on a second side wall part (7; 59) on which preferably a fan wheel (14; 66) is rotatably mounted. Cooking appliance according to one of the preceding claims, characterized in that
in the interior space (10, 11; 62, 63) a flow-guiding element (9; 61) is arranged, which at least partially encloses the interior space (10, 11; 62, 63) in a cooking chamber (10, 62) and a pressure chamber (11; 63), where
in the pressure chamber (11; 63) a fan wheel (14; 66) is arranged,
the flow-guiding element (9; 61) is provided with at least one opening (17; 70), in particular a centrally arranged opening (17; 70), for drawing in atmosphere from the cooking space (10; 62) into the pressure space (11; 63) and
the flow-guiding member (9; 61) between the pressure chamber (11; 63) and the cooking chamber (10; 62), in particular at the edge region of the flow-guiding member (9; 61), at least one connection (18; 75) for blowing out atmosphere from the pressure chamber (11; 63) into the cooking chamber (10; 62) leaves free. Cooking appliance according to claim 5 and 6, characterized in that
the side wall part (8; 60) is aligned or alignable with the fan wheel (14; 66) and / or at a point in the interior space (10, 11; 62, 63), in particular in the cooking space (10; 62). Cooking appliance according to one of the preceding claims, characterized by at least one Mikrowellenleitstruktur (24,25; 28), the microwaves of at least one microwave generator (22,23) leads up to at least to the opening, wherein Preferably, the Mikrowellenleitstruktur (24,25; 28) comprises a portion (30) which extends to the opening, and preferably with a seen in cross section parallel to the direction of propagation of the microwaves round, in particular circular, outer circumference. Cooking appliance according to one of the preceding claims, characterized by a plurality of openings, of which at least two are arranged at different heights in the cooking appliance (1; 53) and each at least one antenna (50; 77) for the radiation of microwaves into the interior (10,11; 62, 63), wherein in particular the antennas (50, 77) are in each case connected to at least one magnetron (22, 23), preferably to a respective rated power of up to 2000 W HF. Cooking appliance according to one of the preceding claims, characterized by at least one further device for the treatment of food in the cooking chamber, in particular at least one device from the group comprising: an electric heater, a gas powered heater, a heat exchange device, a cooling device, a moisture supply device, a moisture removal device, a ventilation device and a venting device. Cooking appliance according to one of the preceding claims, characterized by at least one sensing device, a display device, an operating device and a control or regulating device, wherein the control or regulating device preferably with at least one microwave source, at least one further treatment device, the display device, the operating device and / or the sensing device is in operative connection.

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