Cooking appliance with microwave function and microwave traps

Abstract

The invention relates to a cooking appliance (1) comprising a cooking chamber (3) delimited by a cooking chamber wall (2.1), wherein the cooking chamber wall (2.1) forms a cooking chamber opening (4) of the cooking chamber (3), a cooking chamber door (5) for closing the cooking chamber opening (4) and at least one heating means (8) for generating microwaves in the cooking chamber (3), wherein a shaped part (13) is arranged circumferentially around the cooking chamber opening (4) away from the cooking chamber (3) and adjoining the cooking chamber wall (2.1), wherein the shaped part (13) forms with the cooking chamber wall (2.1) a cavity (14) designed as a microwave trap, wherein the cooking chamber wall (2.1) circumferentially around the cooking chamber opening (4) forms a folded collar (15) projecting into the cavity (14), wherein the shaped part (13) and the folded collar (15) for Forming a trap opening (14.1) adjacent to the cooking chamber opening (4) are spaced apart from one another and wherein the surface of the cooking chamber door (5) is opposite to the trap opening (14.1) is metallic, wherein the folded collar (15) has a slit (18).

Description

Technical area

[0001] The invention relates to a cooking appliance comprising a cooking chamber delimited by a cooking chamber wall, wherein the cooking chamber wall forms a cooking chamber opening of the cooking chamber, a cooking chamber door for closing the cooking chamber opening and at least one heating means for generating microwaves in the cooking chamber. Background of the invention

[0002] Cooking appliances, particularly microwave ovens and ovens with microwave functionality, are known from the prior art. In such cooking appliances, it is necessary to prevent the escape of microwave radiation to avoid endangering people in the vicinity of the cooking appliance. For this purpose, microwave traps in the form of cavities are provided in the area of ​​a door gap on the door side to couple in stray microwave radiation, thus preventing microwave radiation from escaping through the door gap.

[0003] There is a constant need for the aforementioned cooking appliances to be designed to be as easy to clean as possible and also to be visually appealing. However, the disadvantage of existing cooking chamber doors with microwave traps is that the microwave traps create imperfections on the cooking chamber door in that they are not only visually unappealing but also very difficult to clean. This is particularly true if the door is designed as an immersion door, i.e. it protrudes into the cooking chamber, to reliably prevent microwaves from escaping. Another disadvantage for cooking appliances where the microwave function is offered as an option is that it is not practical to use the same cooking chamber door for models with and without a microwave function, which leads to additional costs in production and warehousing.

[0004] From EP 3 940 298 A1 a cooking appliance with a groove surrounding a cooking chamber opening for receiving a sealing element is known.

[0005] Microwave ovens of this type are also known from the documents DE 28 53 616 A1 and US 4 028 519 A. Description of the invention

[0006] Based on the background of the invention, it is an object of the present invention to avoid the aforementioned disadvantages of cooking chamber doors with microwave traps in cooking appliances.

[0007] The object of the invention is achieved by the features of the independent main claim. Advantageous embodiments are specified in the subclaims, the description, and the drawings. To the extent technically feasible, the teachings of the subclaims may be combined arbitrarily with the teachings of the main and subclaims.

[0008] Advantages of the claimed aspects of the invention are explained below, and preferred modified embodiments of the aspects of the invention are described further below. Explanations, particularly regarding advantages and definitions of features, are essentially descriptive and preferred, but not limiting, examples. If an explanation is limiting, this will be expressly stated.

[0009] In particular, the object is accordingly achieved by a cooking appliance having a cooking chamber delimited by a cooking chamber wall, wherein the cooking chamber wall forms a cooking chamber opening of the cooking chamber, a cooking chamber door for closing the cooking chamber opening and at least one heating means for generating microwaves in the cooking chamber, wherein a shaped part is arranged circumferentially around the cooking chamber opening away from the cooking chamber and adjoining the cooking chamber wall, wherein the shaped part forms a cavity designed as a microwave trap with the cooking chamber wall, wherein the cooking chamber wall forms a folded collar projecting into the cavity circumferentially around the cooking chamber opening, wherein the shaped part and the folded collar are spaced apart from one another to form a trap opening adjacent to the cooking chamber opening and wherein the surface of the cooking chamber door opposite the trap opening is metallic.

[0010] A cooking appliance is particularly designed as an oven with an integrated microwave (so-called combination appliance), in which temperatures of approximately 100-250°C, for example, are provided in the cooking chamber for preparing food. The cooking appliance can also be designed as an oven with a pyrolysis function and / or a steam cooking function. The cooking appliance can also be designed as a steam cooker or as a microwave. The cooking chamber wall particularly preferably forms a baking sleeve of an oven, wherein the cooking chamber opening is oriented towards a front of the cooking appliance and can be covered by a pivoting cooking chamber door.

[0011] The heating means for generating microwaves are designed, for example, as a magnetron or a semiconductor element and, in addition to the means for generating the microwave radiation, also include means for coupling the microwave radiation into the cooking chamber, such as appropriate waveguides. The nominal frequency is, in particular, 2.45 GHz plus / minus 50 MHz. In particular, the geometry of the cooking chamber is designed such that the microwaves of the nominal frequency form standing waves therein.

[0012] The solution to the problem with the cooking appliance described above includes the teaching that a microwave trap is formed on the side of the cooking chamber, i.e., opposite the cooking chamber door. The cooking chamber door can then be designed with a simple, particularly easy-to-clean, and visually appealing shape. For example, the cooking chamber door can be designed with a continuous surface on its side facing the cooking chamber, which covers the microwave trap. Furthermore, the cooking chamber door is then subject to no more extensive requirements than the cooking chamber door of a corresponding cooking appliance without a microwave function and accordingly without a microwave trap, so that the cooking chamber door can be designed as a standard part for cooking appliances of the same type in different designs.

[0013] Furthermore, the teaching provides a particularly simple design for the microwave trap on the cooking chamber wall, namely by the cooking chamber wall itself and a single additional molded part. The folded collar forms a capacitance C with the molded part in the area of ​​the trap opening, and a further inner area of ​​the microwave trap beyond the folded collar forms an inductance L between the walls of the molded part and the walls of the cooking chamber wall. The capacitance C and the inductance L together form an oscillating circuit whose resonant frequency is ω=1LC and preferably at a nominal frequency ω0 of the heating means for generating microwaves in the cooking chamber.

[0014] According to the invention, the folded collar has a slit. The slit provides the microwave trap with improved properties with respect to obliquely incident microwaves and microwaves of higher modes, which are then more likely to be coupled into the microwave trap or forced to travel an effective straight path through the trap.

[0015] In addition to the immediately above, the slit can extend over the entire extent of the folded collar that protrudes into the cavity. The area provided by the folded collar within the cavity is then fully utilized for the slit to improve the properties of the microwave trap.

[0016] Alternatively or in addition to the immediately above, it can be provided that the slit of the folded collar directly adjoins its fold radius. The slit is then formed over the maximum available area without mechanically weakening the fold radius in order to improve the properties of the microwave trap. The area of ​​the folded collar assigned to the fold radius is defined by an existing bend and, depending on the design, may or may not extend into the cavity. Preferably, the folded collar is folded relatively tightly, i.e., designed with a small fold radius, so that the extension of the area assigned to the fold radius into the cavity is small.

[0017] Alternatively or additionally, the molded part can be provided as a contact surface for the cooking chamber door. The molded part then fulfills an additional function, and the contact surface is formed continuously from the microwave trap. This allows for the elimination of additional components for forming the contact surface, which is advantageous for production, and prevents the creation of additional defects on the cooking appliance, which may be difficult to clean. The contact surface formed by the molded part is preferably in the same plane as a front edge of the folded collar.

[0018] Alternatively or additionally, the cooking chamber door can be provided with a viewing window, with the viewing window extending over the trap opening. The cooking chamber door then forms a continuous, easy-to-clean, and attractive surface with which the microwave trap is covered. An area of ​​the cooking chamber door opposite the microwave trap is then coated with metal, for example, to ensure the proper functioning of the microwave trap.

[0019] Alternatively or additionally, the inner surfaces of the cavity may be metallic. Particularly preferably, the cooking chamber wall and / or the molded part are made of a metallic material. The cooking chamber trap can then be designed to be particularly compact due to the good conductivity of the metallic surface relative to the nominal frequency of the microwaves.

[0020] Alternatively or additionally, it can be provided that at least one metallic surface is formed by a metallic coating. In particular, a metallic surface of the cooking chamber door is formed as a coating that can be particularly easily applied to a smooth, non-metallic surface of the cooking chamber door, for example, to a glass pane.

[0021] Alternatively or additionally, the cooking appliance can be designed as an oven with a microwave function or a steamer with a microwave function. With regard to an oven or steamer, the particular advantage is that the solution described above allows the use of the same cooking chamber door as in a corresponding model without a microwave function, possibly supplemented by the provision of a metallic surface on the cooking chamber door. Short description of the drawings

[0022] A preferred technical solution is explained in more detail below with reference to the accompanying drawings using preferred embodiments. The term "figure" is abbreviated to "Fig." in the drawings.

[0023] The drawings show Fig. 1 a schematic view of a cooking appliance according to an embodiment; Fig. 2 a sectional view in the edge area of ​​a cooking chamber in a cooking appliance in one embodiment; and Fig. 3 a schematic cut-out representation of a slotted area of ​​a folding collar in a cooking appliance as well as in Fig. 2 shown. Detailed description of the drawings

[0024] The described embodiments are merely examples that can be modified and / or supplemented in a variety of ways within the scope of the claims. Each feature described for a specific embodiment can be used independently or in combination with other features in any other embodiment. Each feature described for an embodiment of a specific claim category can also be used correspondingly in an embodiment of another claim category.

[0025] Fig. 1 schematically shows a cooking appliance 1 designed as an oven with a housing 2, wherein a cooking chamber 3 designed as a baking sleeve is formed in the housing 2 and is surrounded by a cooking chamber wall 2.1. The cooking chamber 3 is accessible through a front cooking chamber opening 4, in particular for inserting and removing food to be cooked, wherein the cooking chamber opening 4 can be closed by means of a cooking chamber door 5 shown open. In a closed state, the cooking chamber door 5 rests in a contact surface 2.2 of the housing 2 on the housing 2, circumferentially to the cooking chamber 3. The cooking appliance 1 has heating means, such as a circulating air heating means 6 with a fan (not shown in detail), heating means 7.1, 7.2 for generating radiant heat in a top and bottom heat mode and hidden heating means 8 for generating microwaves of a nominal frequency ω0, wherein the heating means 8 for generating microwaves is arranged such that the microwaves are coupled into the cooking chamber 3.The heating means 8 for generating microwaves is, for example, a magnetron or a semiconductor generator. Furthermore, for illustrative purposes, internal components 9 with a food support 10 resting thereon are arranged in the cooking appliance 1. The cooking appliance 1 also has control elements 11 and a display 12.

[0026] Fig. 2 shows a section through the cooking chamber 3 or a section of an edge area of ​​such a section in the area of ​​the cooking chamber opening 4. The area surrounding the cooking chamber opening 4 forms a contact surface 2.2 for the Fig. 2 cooking chamber door 5 (not shown again), wherein a door gap is created when the cooking chamber door 5 is closed. Adjacent to the cooking chamber wall 2.1, away from the cooking chamber 3 and surrounding the cooking chamber opening 4, shown here in an upper region of the cooking chamber 3, is a molded part 13 which forms a cavity 14 with the cooking chamber wall 2.1. The cavity 14 forms a microwave trap for coupling in microwaves that have crashed in the region of the door gap and has a trap opening 14.1 adjacent to the cooking chamber opening 4. The cooking chamber door 5 (not shown) is metallically formed, in particular metallically coated, in an area that lies opposite the trap opening 14.1 when the cooking chamber door 5 is closed, without any corresponding representation in the figures.

[0027] The cooking chamber wall 2.1 forms a folded collar 15, wherein the folded collar 15 extends with an end section 15.1 into the cavity 14. To form the folded collar 15, the cooking chamber wall 2.1 is bent at the end with a radius, wherein Fig. 2, idealized 90° bends are shown. The folded collar 15 forms, with a part of the molded part 13 in the area of ​​the trap opening 14.1, a pair of opposing metallic surfaces 16.1, 16.2, which together form a capacitance C. Beyond the folded collar 15 within the cavity 14, the molded part 13 and the cooking chamber wall 2.1 have further metallic surfaces 17.1, 17.2, 17.3 for forming an inductance L. The capacitance C and the inductance L together form an oscillating circuit. Furthermore, the molded part 13 forms the system 2.2, which lies in a plane with a front edge 15.2 of the folded collar 15.

[0028] On the folded collar 15, a slot 18 is formed with several slots 18.1 arranged at regular intervals along the circumferential direction of the cooking chamber 3. In Fig. 2 the slit 18 is shown in the background of the drawing plane. Fig. 3 further shows, for illustrative purposes, the end section 15.1 of the folded collar 15 with the slit 18, as an example. The slit 18 extends over the entire extent of the end section 15.1 of the folded collar 15 projecting into the cavity 14. Furthermore, Fig. 2 in the background of the drawing plane a front frame 19 of the cooking appliance 1 is shown, which surrounds the cooking chamber door 5 when the cooking chamber door 5 is closed. List of reference symbols 1 cooking appliance 2 housings 2.1 Cooking chamber wall of the housing 2.2 Housing contact surface 3 Cooking chamber 4 Cooking chamber opening 5 Cooking chamber door 6 circulating air heating 7.1 Heating medium for generating radiant heat 7.2 Heating means for generating radiant heat 8 Heating means for generating microwaves 9 fixtures 10 food carriers 11 Control element 12 Advertisement 13 molded part 14 Cavity 14.1 Trap opening 15 folded collars 15.1 end section of the folded collar 15.2 front edge of the folded collar 16.1 metallic surface forming a capacity C 16.2 metallic surface forming a capacity C 17.1 metallic surface forming an inductance L 17.2 metallic surface forming an inductance L 17.3 metallic surface forming an inductance L 18 slits 18.1 Slot of the slot 19 front frame

Claims

Cooking appliance (1), comprising a cooking chamber (3) delimited by a cooking chamber wall (2.1), the cooking chamber wall (2.1) forming a cooking chamber opening (4) of the cooking chamber (3); a cooking chamber door (5) for closing the cooking chamber opening (4); andat least one heating means (8) for generating microwaves in the cooking chamber (3);wherein a shaped part (13) is arranged adjacent to the cooking chamber wall (2.1) surrounding the cooking chamber opening (4) away from the cooking chamber (3), the shaped part (13) forming a cavity (14) designed as a microwave trap with the cooking chamber wall (2.1);wherein the cooking chamber wall (2.1) forming a folded collar (15) projecting into the cavity (14) surrounding the cooking chamber opening (4);wherein the shaped part (13) and the folded collar (15) are spaced apart from one another to form a trap opening (14.1) adjacent to the cooking chamber opening (4);andwherein the surface of the cooking chamber door (5) opposite the trap opening (14.1) is metallic, characterized in that the folded collar (15) has a slit (18). Cooking appliance (1) according to claim 1, wherein the slit (18) extends over the entire extent of the folded collar (15) projecting into the cavity (14). Cooking appliance (1) according to claim 1 or 2, wherein the slit (18) of the folding collar (15) directly adjoins its folding radius. Cooking appliance (1) according to one of the preceding claims, wherein the shaped part (13) forms a contact surface (2.2) for the cooking chamber door (5). Cooking appliance (1) according to one of the preceding claims, wherein the cooking chamber door (5) has a viewing window, the viewing window extending over the trap opening (14.1). Cooking appliance (1) according to one of the preceding claims, wherein inner surfaces (16.1, 16.2, 17.1, 17.2, 17.3) of the cavity (14) are metallic. Cooking appliance (1) according to one of the preceding claims, wherein at least one metallic surface (16.1, 16.2, 17.1, 17.2, 17.3) is formed by a metallic coating. Cooking appliance (1) according to one of the preceding claims, designed as an oven with microwave function or steamer with microwave function.

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