Method for operating a heating means of a cooking appliance

Abstract

The invention relates to a method (10) for operating a heating means (8) of a cooking appliance (1). The heating means (8) is made of a conductive material, and the heating means (8) lies opposite another conductive element (9) of the cooking appliance (1) such that a cooking chamber (6) of the cooking appliance (1) extends between the heating means (8) and the other conductive element (9). According to one aspect of the invention, in an alternating manner, an alternating voltage is applied to or generated on the heating means (8) across from the other conductive element (9) in order to generate an electromagnetic alternating field (11) which passes through the cooking chamber (6) and a current is applied to or generated on the heating means in order to heat the heating means (8) by means of ohmic losses (12). The invention additionally relates to a corresponding cooking appliance (1) which is designed to carry out such a method.

Description

[0001] Method for operating a heating means of a cooking appliance

[0002] Technical area

[0003] The invention relates to a method for operating a heating means of a cooking appliance, wherein the heating means is formed from a conductive material and wherein the heating means is arranged opposite a further conductive element of the cooking appliance, such that a cooking chamber of the cooking appliance extends between the heating means and the further conductive element. Furthermore, the invention relates to a corresponding cooking appliance configured to carry out such a method.

[0004] Background of the invention

[0005] A wide variety of cooking appliances such as ovens, steamers, microwaves, stoves, warming drawers, and the like are known from the state of the art. Often, several cooking functions are combined in single cooking appliances. Combined cooking appliances require separate heating elements for each function, each of which must be accommodated within the limited space available, making the design of the cooking appliance correspondingly complex and expensive.

[0006] EP 3 701 769 B1, for example, discloses a furnace with multiple functions, including several low-frequency generating devices.

[0007] Description of the invention

[0008] Based on the background of the invention, it is an object of the present invention to enable or propose a cooking appliance with a wide range of functions while requiring little space.

[0009] The object of the invention is achieved by the features of the independent main claims. Advantageous embodiments are specified in the subclaims. To the extent technically feasible, the teachings of the subclaims can be combined arbitrarily with the teachings of the main and subclaims.

[0010] 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.

[0011] According to a first aspect of the invention, the object is achieved by a method for operating a heating means of a cooking appliance, wherein the heating means is formed from a conductive material and wherein the heating means is arranged opposite a further conductive element of the cooking appliance, so that a cooking chamber of the cooking appliance extends between the heating means and the further conductive element, wherein an alternating voltage is alternately applied or generated at the heating means with respect to the further conductive element for generating an alternating electromagnetic field passing through the cooking chamber and a current is alternately applied or generated for heating the heating means by ohmic losses.

[0012] A heating means is understood to be a means designed to influence the temperature of the food being cooked. This includes both the transfer of heat between the heating means and the food being cooked through heat transfer, in particular thermal radiation and convection, as well as influencing the temperature of the food being cooked in other ways, in particular by stimulating ion and / or molecular movement in the food being cooked through electromagnetic radiation.

[0013] The solution to the problem with the method described above therefore comprises the teaching that the heating medium is heated on the one hand to generate radiant heat acting on the food being cooked and on the other hand is operated to generate an alternating electromagnetic field. An alternating electromagnetic field is understood to be an electromagnetic field with alternating polarity. Such an alternating electromagnetic field penetrates the food being cooked and generates ion movement and rotation of dipolar molecules within the food, so that the food is heated evenly. The alternation between generation of the alternating field and heating of the heating medium by current flow preferably occurs in quick succession so that no significant cooling of the heating medium occurs during the time the alternating electromagnetic field is generated and a desired heating medium temperature can be reached and / or maintained.For example, a change occurs within a few milliseconds to a few seconds.

[0014] Using the method described, the heating means can provide two functions simultaneously, namely electromagnetic heating and heating of the food to be cooked by means of thermal radiation. Both functions are therefore available for simultaneous use in the cooking appliance, wherein only the heating means and the conductive element, which are required anyway to provide an alternating electromagnetic field, need be provided. Separate means for generating thermal radiation can therefore be dispensed with, so that the number of components in the cooking appliance and the space required for this are reduced. Furthermore, it can also be provided that the heating means is only subjected to an alternating voltage compared to the other conductive element in order to generate an alternating electromagnetic field, or that it is only subjected to an applied orThe electricity generated therein is used to generate radiant heat, so that the aforementioned functions are also available individually in the cooking appliance. The advantages of the respective functions can be utilized in various cooking methods, while only one device is provided in a space-saving manner.

[0015] The frequency of the alternating electromagnetic field is preferably in the range of a few megahertz to a few hundred megahertz, approximately between 1 megahertz and 500 megahertz, particularly preferably in the ISM bands, e.g., 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 enable an alternating electromagnetic field favorable for heating food and are available without a license in many countries.

[0016] In one embodiment, the current is generated by applying a voltage between two conductor ends of the heating means, in particular at a frequency of 50 or 60 Hertz. A conductor end is, for example, a side or edge of a plate or an end of a wire, in particular a wire designed as a coil. At the proposed frequencies of 50 or 60 Hertz, the mains voltage available in conventional power grids can be used for this purpose, and transformation is unnecessary. Alternatively, the current from a power source can be applied to the heating means or impressed upon the heating means.

[0017] The object is also achieved according to a second aspect of the invention by a cooking appliance for cooking food, comprising at least one heating means, wherein the heating means is formed from a conductive material and wherein the heating means is arranged opposite a further conductive element of the cooking appliance, so that a cooking chamber of the cooking appliance extends between the heating means and the further conductive element, wherein the cooking appliance is configured to carry out a method described above. The advantages described above with regard to the method can be achieved accordingly with the cooking appliance.

[0018] If the cooking appliance is designed for cooking food, it allows for cooking in the narrower sense, i.e., raising the temperature of the food to at least a specific cooking temperature. However, cooking also includes influencing the temperature of the food in other ways, such as defrosting or keeping it warm.

[0019] The heating means is preferably designed as a plate or flat coil. A plate, within the meaning of the present disclosure, also includes an arrangement of multiple plates that together form a plate-shaped region, for example, in a tile-like arrangement. A flat coil is furthermore particularly preferably designed as a meandering coil or helical coil. A plate or flat coil can also comprise multiple parts that act in particular on different regions of the cooking chamber and are particularly preferably controllable independently of one another.

[0020] Particularly preferably, the heating means and the further conductive element together form a capacitor, thus a corresponding voltage source is connected to the heating element on the one hand and – with opposite polarity – to the further conductive element. In particular, the heating means and the further conductive element are designed as identical parts, for example, both as a plate or flat coil.

[0021] The cooking appliance is designed, for example, as an oven, as a tabletop appliance, as a microwave, as a steamer, or any combination thereof. The cooking appliance is particularly preferably designed as a warming drawer arrangement. In such a case, the described advantages regarding the small installation space requirement are particularly desirable. In principle, and as already partially described above, means for providing (additional) functions are provided in or on the cooking appliance in any combinations, in particular additional radiant heating means, means for providing a grill function, means for providing a circulating air heating function, means for providing a microwave function beyond that described above, means for providing an ultrasonic treatment function, means for providing a steaming function, means for providing an evacuation function, and / or means for providing a cooling function.

[0022] Short description of the drawings

[0023] The invention will be explained in more detail below with reference to preferred embodiments and the accompanying drawings. The term "figure" is abbreviated to "Fig."

[0024] The drawings show

[0025] Fig. 1a is a schematic cross-sectional view of a cooking appliance according to the second aspect of the invention in one embodiment;

[0026] Fig. 1b is a schematic cross-sectional view of a cooking appliance according to the first aspect of the invention in a further embodiment; and

[0027] Fig. 2 is a process diagram of a method according to the first aspect of the invention. Detailed Description of the Drawings

[0028] 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 a different claim category.

[0029] Figure 1a shows a cooking appliance 1 in the form of a warming drawer arrangement in a first embodiment in a highly schematic lateral cross-sectional view. The cooking appliance 1 comprises a housing 2, which is formed, for example, in a kitchen cupboard and has an upper wall 2.1, a lower wall 2.2, a right wall 2.3 and a left wall 2.4. In the housing 2, a drawer 3 is slidably arranged on guide means (not shown), of which only a base 3.1 is shown in the schematic view. The housing 2 and the drawer 3 together form a cooking chamber 6, wherein the base 3.1 forms a support area 4 for a food 5 to be cooked located in the cooking chamber 6.

[0030] The upper wall 2.1 of the housing 2 is formed from glass in a central region 7.1. Outside the housing 2, in alignment with this central region 7.1, a heating means 8 is arranged for generating an alternating electromagnetic field (not shown in detail) that permeates the cooking chamber 6, on the one hand, and for emitting heat radiation to the food 5, on the other hand. Both the alternating field and the heat radiation can penetrate the glass of the central region 71 largely without resistance. The heating means 8 is designed as a conductive plate to which a voltage with a corresponding frequency for generating the alternating field in the range of a few megahertz to a few hundred megahertz is applied. A corresponding further conductive element 9, also designed as a conductive plate, is arranged below the lower wall 2.2 with a central region 7, also made of glass.2 and forms a capacitor arrangement with the heating means 8. The alternating electromagnetic field is thus limited to the area between the heating means 8 and the further conductive element 9.

[0031] Figure 1b shows an embodiment of the cooking appliance 1 essentially corresponding to the embodiment of Figure 1a in the same view, but with the heating means 8 arranged within the cooking chamber 6 on an inner side of the upper wall 2.1. The heating means 8 is then arranged closer to the food 5, so that the food 5 is better penetrated by the alternating field and the heat radiation acts on the food 5 with a shorter radiation path.

[0032] Figure 2 shows a diagram of a method 10 according to the first aspect of the invention. In a first step 11, an alternating voltage is applied to the heating means 8 across the further conductive element 9 to generate an alternating electromagnetic field that permeates the cooking chamber 6. The alternating field generates ionic movement and rotation of dipolar molecules in the food 5 to be cooked, so that the food 5 is heated evenly. In a second step 12, a current is applied or generated to the heating means 8 to heat the heating means 8 through ohmic losses. The thus heated heating means 8 then radiates heat radiation, which heats the surface of the food 5 and cooks it accordingly. The first step 11 and the second step 12 are performed in continuous alternation, with a change occurring, for example, after a certain period of time, approximately on the order of milliseconds or seconds. Alternatively, the period of time can also be variable.

[0033] List of reference symbols

[0034] 1 cooking appliance

[0035] 2 housings

[0036] 2.1 upper wall of the housing

[0037] 2.2 lower wall of the housing

[0038] 2.3 right wall of the housing

[0039] 2.4 left wall of the housing

[0040] 3 drawers

[0041] 3.1 Bottom of the drawer

[0042] 4 Support area

[0043] 5 Food to be cooked

[0044] 6 Cooking chamber

[0045] 7.1 middle area of ​​the upper wall

[0046] 7.2 middle area of ​​the lower wall

[0047] 8 Heating agents

[0048] 9 additional conductive element

[0049] 10 procedures

[0050] 11 First step of the procedure - Applying an alternating voltage

[0051] 12 second step of the process - applying or generating a current

Claims

Patent claims 1. Method (10) for operating a heating means (8) of a cooking appliance (1); wherein the heating means (8) is formed from a conductive material; and wherein the heating means (8) is arranged opposite a further conductive element (9) of the cooking appliance (1), such that a cooking chamber (6) of the cooking appliance (1) extends between the heating means (8) and the further conductive element (9); characterized in that an alternating voltage is alternately applied or generated at the heating means (8) with respect to the further conductive element (9) for generating an alternating electromagnetic field (11) penetrating the cooking chamber (6), and a current is alternately applied or generated at the heating means (8) for heating the heating means (8) through ohmic losses (12).

2. Method (10) according to claim 1, wherein the frequency of the alternating electromagnetic field is between 1 megahertz and 500 megahertz, in particular in an ISM band.

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

4. Cooking appliance (1) for cooking a food item (5), comprising at least one heating means (8), wherein the heating means (8) is made of a conductive material; and wherein the heating means (8) is arranged opposite a further conductive element (9) of the cooking appliance (1), so that a cooking chamber (6) of the cooking appliance (1) extends between the heating means (8) and the further conductive element (9), characterized in that the cooking appliance (1) is designed to carry out a method according to one of the preceding claims.

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

6. Cooking appliance (1) according to claim 4 or 5, wherein the heating means (8) and / or the further conductive element (9) is / are designed as a plate or flat coil.

7. Cooking appliance (1) according to one of claims 4 to 6, designed as a warming drawer arrangement.

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