Method for operating heating device of cooking appliance

Abstract

The invention relates to a method (10) for operating a heating device (8) of a cooking appliance (1), in which the heating device (8) is made of an electrically conductive material, and in which the heating device (8) is arranged opposite a further electrically conductive element (9) of the cooking appliance (1) such that a cooking chamber (6) of the cooking appliance (1) extends between the heating device (8) and the further electrically conductive element (9). According to one aspect of the invention, an alternating voltage is applied or generated on the heating device (8) relative to the other electrically conductive element (9) in an alternating manner in order to generate an electromagnetic alternating field (11) through the cooking chamber (6), and a current is applied or generated on the heating device (8) in order to heat the heating device by means of an ohmic loss (12). The invention also relates to a corresponding cooking appliance (1) configured to carry out the method.

Description

Technical Field

[0001] The present invention relates to a method for operating a heating device of a cooking appliance, wherein the heating device is made of an electrically conductive material and wherein the heating device is arranged opposite another electrically conductive element of the cooking appliance, such that a cooking chamber of the cooking appliance extends between the heating device and the further electrically conductive element. Furthermore, the present invention relates to a corresponding cooking appliance configured to perform the method. Background Art

[0002] A wide variety of cooking appliances are known in the art, such as ovens, steamers, microwave ovens, stovetops, and warming drawers. These appliances typically combine multiple cooking functions within a single appliance. In combination cooking appliances, each function requires a separate heating device that must be accommodated within the limited available space, making the design of the cooking appliance correspondingly complex and expensive.

[0003] For example, EP 3 701 769 B1 discloses an oven having multiple functions including a plurality of low frequency generating devices. Summary of the Invention

[0004] Starting from the background of the present invention, the object of the present invention is to provide or propose a cooking appliance having multiple functions and minimal space requirement.

[0005] The object of the invention is achieved by the features of the independent main claim. Advantageous embodiments are described in detail in the dependent claims. The teachings of the dependent claims can be combined with the teachings of the main claim and the dependent claims in any manner, as far as technically feasible.

[0006] The advantages of the claimed aspects of the present invention will be described below, and preferred embodiments of these aspects of the present invention will be further described below. In particular, the explanations regarding advantages and feature definitions are illustrative and preferred in nature, rather than limiting. If the explanations are limiting, this will be explicitly stated.

[0007] According to a first aspect of the invention, the object is achieved by a method for operating a heating device of a cooking appliance, wherein the heating device is made of an electrically conductive material and wherein the heating device is arranged opposite a further electrically conductive element of the cooking appliance so that a cooking chamber of the cooking appliance extends between the heating device and the further electrically conductive element, wherein an alternating voltage is applied or generated to the heating device relative to the further electrically conductive element in order to generate an electromagnetic alternating field through the cooking chamber, and an electric current is applied or generated to the heating device in an alternating manner in order to heat the heating device by means of ohmic losses.

[0008] A heating device is understood to be a device configured to influence the temperature of the food. This includes transferring heat between the heating device and the food by heat transfer, in particular thermal radiation and convection, as well as influencing the temperature of the food by other means, in particular by stimulating ionic and / or molecular motions in the food by electromagnetic radiation.

[0009] Therefore, achieving this object by the above-described method includes the following teachings: the heating device is heated to generate radiant heat that acts on the food, and is also driven to generate an electromagnetic alternating field. An electromagnetic alternating field is defined as an electromagnetic field with alternating polarity. This electromagnetic alternating field penetrates the food and induces ion motion and rotation of dipole molecules therein, resulting in uniform heating of the food. The alternation between generating the alternating field and heating the heating device with electric current preferably occurs continuously within a short period of time, such that the heating device does not significantly cool during the time the electromagnetic alternating field is generated, and the desired heating device temperature can be reached and / or maintained. For example, the alternation occurs within a few milliseconds to a few seconds.

[0010] Using this method, the heating device can simultaneously provide two functions: electromagnetic heating and heating through thermal radiation from the food. Therefore, both functions can be used simultaneously in a cooking appliance, requiring only the heating device and the conductive element, which are required to generate the electromagnetic alternating field. This eliminates the need for a separate device for generating radiant heat, thereby reducing the number of components and the space required in the cooking appliance. Furthermore, the heating device can be heated solely by an alternating voltage applied to or generated by another conductive element to generate the electromagnetic alternating field, or by an electric current applied or generated therein to generate radiant heat, allowing the aforementioned functions to be used independently in the cooking appliance. This cooking appliance allows the advantages of specific functions to be utilized in various cooking methods while providing only a single device, thus saving space.

[0011] The frequency of the electromagnetic alternating field is preferably in the range of several megahertz to several hundred megahertz, approximately between 1 megahertz and 500 megahertz, and particularly preferably in the ISM frequency band, for example 6.765 MHz to 6.795 MHz, 13.553 MHz to 13.567 MHz, 25.565 MHz to 27.405 MHz, 40.66 MHz to 40.70 MHz, and 433 MHz to 444 MHz. These frequencies allow the generation of electromagnetic alternating fields that are advantageous for heating food and can be used without a license in many countries.

[0012] In one embodiment, the current is generated by applying a voltage between two conductor ends of the heating device, in particular at a frequency of 50 Hz or 60 Hz. The conductor ends are, for example, the sides or edges of a plate, or the ends of a conductor (in particular, a conductor forming a coil). At the proposed frequency of 50 Hz or 60 Hz, the mains voltage available from a conventional power grid can be used without any voltage transformation. Alternatively, the current can be applied to the heating device from a power supply, or forced onto the heating device.

[0013] According to a second aspect of the present invention, this object is also achieved by a cooking appliance for cooking food, the cooking appliance comprising at least one heating device, wherein the heating device is made of an electrically conductive material, and wherein the heating device is arranged opposite another electrically conductive element of the cooking appliance, such that a cooking chamber of the cooking appliance extends between the heating device and the further electrically conductive element, wherein the cooking appliance is configured to perform the above-described method. The cooking appliance can be used to achieve the advantages of the above-described method.

[0014] Cooking in the narrow sense is particularly permissible if the cooking appliance is designed for cooking food, i.e. raising the temperature of the food to at least a food-specific cooking temperature. However, cooking can also be understood as influencing the temperature of the food in other ways, such as thawing or keeping the food warm.

[0015] The heating device is preferably designed as a plate or a flat coil. Within the meaning of the present disclosure, a plate also includes an assembly of multiple plates that together form a plate-like area, for example, a tile-like assembly. Furthermore, the flat coil is particularly preferably designed as a meandering coil or a spiral coil. The plate or flat coil can also consist of multiple components, which in particular act on different areas of the cooking chamber and are particularly preferably independently controllable.

[0016] Particularly preferably, the heating device and the further conductive element together form a capacitor, i.e., the corresponding voltage source is connected to the heating element on the one hand and to the other conductive element with the opposite polarity. In particular, the heating device and the further conductive element are designed as the same component, for example, both are designed as plates or flat coils.

[0017] The cooking appliance is designed, for example, as an oven, tabletop appliance, microwave oven, steamer, or any combination thereof. Particularly preferably, the cooking appliance is designed as a warming drawer assembly. In this case, the aforementioned advantages regarding the small installation space requirement are particularly pronounced. In principle, as described above, devices for providing (additional) functions can be provided in or on the cooking appliance in any combination of embodiments, in particular, further radiant heating devices, devices for providing a grilling function, devices for providing a circulating air heating function, devices for providing a microwave function beyond the aforementioned functions, devices for providing an ultrasonic treatment function, devices for providing a steaming function, devices for providing a vacuuming function, and / or devices for providing a cooling function. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be described in more detail below using preferred exemplary embodiments with reference to the accompanying drawings. In the accompanying drawings, the term "drawing" is abbreviated as "figure".

[0019] In the attached figure:

[0020] Figure 1a is a schematic cross-sectional view of an embodiment of a cooking appliance according to the second aspect of the present invention;

[0021] Figure 1b is a schematic cross-sectional view of another embodiment of the cooking appliance according to the first aspect of the present invention; and

[0022] Figure 2 is a flow chart of a method according to the first aspect of the present invention. DETAILED DESCRIPTION

[0023] The exemplary embodiments described are merely examples and may be modified and / or supplemented in various ways within the scope of the claims. Each feature described with respect to a particular exemplary embodiment may be used independently or in combination with other features of any other exemplary embodiment. Each feature described with respect to an exemplary embodiment of a particular claim category may also be used with respect to an exemplary embodiment of another claim category.

[0024] Figure 1a A first embodiment of a cooking appliance 1 in the form of an electric heating drawer assembly is shown in a highly schematic side cross-sectional view. The cooking appliance 1 comprises a housing 2, which is formed, for example, in a kitchen cabinet and has an upper wall 2.1, a lower wall 2.2, a right wall 2.3, and a left wall 2.4. Within the housing 2, a drawer 3 is arranged to be movable along guides (not shown); only its base 3.1 is shown in this schematic diagram. The housing 2 and drawer 3 together form a cooking chamber 6, with the base 3.1 forming a placement area 4 for food 5 located within the cooking chamber 6.

[0025] The central region 7.1 of the upper wall 2.1 of the housing 2 is made of glass. A heating device 8 is arranged outside the housing 2, aligned with this central region 7.1. This serves, on the one hand, to generate an electromagnetic alternating field (not shown in detail) that penetrates the cooking chamber 6, and, on the other hand, to emit thermal radiation toward the food 5. Both the alternating field and the thermal radiation can penetrate the glass of the central region 7.1 with virtually no resistance. The heating device 8 is designed as a conductive plate, to which a voltage of a corresponding frequency is applied to generate the alternating field in the range of several megahertz to several hundred megahertz. A corresponding further conductive element 9 (also designed as a conductive plate) is arranged below the lower wall 2.2, whose central region 7.2 is also made of glass. This element forms a capacitive component with the heating device 8. The electromagnetic alternating field is thus confined to the region between the heating device 8 and the further conductive element 9.

[0026] Figure 1b The same view shows Figure 1a The embodiment of the cooking device 1 corresponds substantially to the embodiment of the cooking device 1, but the heating device 8 is arranged on the inner side of the upper wall 2.1 of the cooking chamber 6. In this case, the heating device 8 is arranged closer to the food 5, so that the alternating field penetrates the food 5 better and the heat radiation acts on the food 5 via a shorter radiation path.

[0027] Figure 2 A schematic diagram of a method 10 according to a first aspect of the present invention is shown. In a first step 11, an alternating voltage is applied to a heating device 8 relative to another conductive element 9 to generate an electromagnetic alternating field across the cooking chamber 6. This alternating field induces ionic motion and rotation of dipole molecules in the food 5, resulting in uniform heating of the food 5. In a second step 12, an electric current is applied or generated to the heating device 8 to heat it through ohmic losses. The heated heating device 8 then radiates heat, heating the surface of the food 5 and cooking it accordingly. The first and second steps 11 and 12 are performed continuously and alternately, for example, changing after a certain time period of approximately milliseconds or seconds. Alternatively, the time period can also be variable.

[0028] Reference Signs List

[0029] 1 cooking utensils

[0030] 2 Shell

[0031] 2.1 Upper wall of the shell

[0032] 2.2 Lower wall of the shell

[0033] 2.3 Right wall of the shell

[0034] 2.4 Left wall of the shell

[0035] 3 drawers

[0036] 3.1 Drawer base

[0037] 4 Placement Area

[0038] 5. Food

[0039] 6 Cooking Room

[0040] 7.1 Central area of ​​the upper wall

[0041] 7.2 Central area of ​​the lower wall

[0042] 8 Heating device

[0043] 9 Another conductive element

[0044] 10 Methods

[0045] 11. The first step of the method - applying alternating voltage

[0046] 12. The second step of the method - applying or generating electric current

Claims

1. A method (10) for operating a heating device (8) of a cooking appliance (1); in, The heating device (8) is made of a conductive material; and wherein the heating device (8) is arranged opposite to another conductive element (9) of the cooking utensil (1), so that the cooking chamber (6) of the cooking utensil (1) extends between the heating device (8) and the other conductive element (9); It is characterized in that In an alternating manner, an alternating voltage is applied or generated to the heating device (8) relative to the further conductive element (9) in order to generate an electromagnetic alternating field (11) passing through the cooking chamber (6), and an electric current is applied or generated to the heating device (8) in order to heat the heating device by means of ohmic losses (12).

2. The method (10) according to claim 1, wherein: The frequency of the electromagnetic alternating field is between 1 MHz and 500 MHz, in particular in the ISM band.

3. The method (10) according to claim 1 or 2, wherein: The current is generated by applying a voltage between two conductor ends of the heating device (8), in particular at a frequency of 50 Hz or 60 Hz.

4. A cooking appliance (1) for cooking food (5), comprising at least one heating device (8), in, The heating device (8) is made of a conductive material; and wherein the heating device (8) is arranged opposite to another conductive element (9) of the cooking appliance (1), so that the cooking chamber (6) of the cooking appliance (1) extends between the heating device (8) and the other conductive element (9), It is characterized in that The cooking appliance (1) is configured to perform the method according to any one of the preceding claims.

5. The cooking appliance (1) according to claim 4, wherein The heating device (8) and the further conductive element (9) together form a capacitor.

6. The cooking appliance (1) according to claim 4 or 5, wherein: The heating device (8) and / or the further electrically conductive element (9) are designed as a plate or a flat coil.

7. The cooking appliance (1) according to any one of claims 4 to 6, being designed as a warming drawer assembly.

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