EP3273165A1 - Cooking field device, and method for operating the same - Google Patents

Abstract

Cooking field device (1) comprising a housing device (2), a frame device (3) and a mounting plate (4). On the frame means (3) two weighing devices (5) are arranged, on which the mounting plate (4) rests. Furthermore, the mounting plate (4) is associated with a cooking vessel identification device (50). When operating the cooking field device, conclusions about the state of a cooking vessel and / or about the state of at least one cooking process in at least one cooking vessel are drawn via weight recognition by means of the weighing device (5) and a cooking vessel identification by means of the cooking vessel identification device (50).

Description

The present invention relates to a cooking field device comprising at least one mounting plate. The present invention further relates to a method for operating such a cooking field device.

Modern household appliances usually offer a user a number of program supports and / or automatic programs in order to make the operation of the household appliance particularly comfortable.

Especially with cooking appliances, a user can be supported very much in the preparation of food on partially or even fully automated cooking processes. For example, some hobs offer boiling point detection. Known boiling point detectors often use structure-borne sound measurements to infer conclusions about a boiling process. Such methods usually work reliably.

The disadvantage, however, is that with structure-borne noise measurements, the monitoring of low power is not possible and that when refilling or refilling cold food no monitoring of the cooking process takes place until a boiling process on the structure-borne noise measurement is detected. A continuous adjustment of the performance to the current heat demand can not take place. In addition, the monitoring of several cooking vessels on a hob is difficult.

It is therefore the object of the present invention to better assist a user in preparing food on a cooktop.

This object is achieved by a cooking field device with the features of claim 1 and by a method for operating such a cooking field device with the features of claim 4. Preferred developments of the invention are the subject of the dependent claims. Further advantages and features of the invention will become apparent from the embodiments.

The cooking field device according to the invention comprises at least one mounting plate and at least one, in particular at least two weighing devices The mounting plate is configured to receive at least one cooking vessel. The weighing devices are configured, in the installed position of the hob, to detect a weight force acting on the mounting plate.

Furthermore, the mounting plate is assigned at least one cooking vessel identification device. The cooking vessel identification device is configured to detect the footprint of a cooking vessel arranged on the setting plate.

The terms footprint and area of the pot bottom and pot size are used synonymously below.

The cooking field device according to the invention preferably further comprises at least one heating device, by means of which on the mounting plate upstanding cooking vessels can be heated. In this case, the mounting plate is designed in particular as a ceran disk, on which one or more cooking zones are provided. The heating device may preferably comprise at least one induction coil, at least one gas burner and / or at least one other type of thermal heat source.

Furthermore, preferably at least one control device and / or at least one operating device is provided, via which the power of at least one heating device for at least one hotplate can be set.

In addition, the cooking field device is in particular designed such that a user is provided at least one automatic program and / or at least one cooking assistance when preparing food on the cooking field device according to the invention. For this purpose, at least one control and / or regulating electronics of the cooking field device is expediently associated with or associated with the cooking field device.

The cooking field device further preferably comprises a housing device and / or a frame device. The weighing devices can be arranged between a frame device on the one hand and the mounting plate and / or the housing device on the other hand. In this case, the frame means is preferably attached to the worktop and the other parts of the cooking field device store by means of weighing devices on the frame means.

Other embodiments of the cooking field device are possible according to the invention. The frame device is preferably part of the housing device or is provided by the housing device and / or is formed as a separate component. For example, the weighing devices can be arranged between the housing device and / or frame device and / or the worktop on the one hand and the mounting plate on the other hand.

A particularly favorable embodiment provides that the weighing devices are held on the housing device and bear on the one hand on the mounting plate and on the other hand on the frame means and / or the worktop for detecting a gravitational force.

The weighing devices preferably comprise at least one sensor device, which is designed in particular as a weighing sensor. About such a weighing sensor or via the weighing devices, the force acting on the mounting plate force can be determined. For this purpose, the mounting plate preferably rests exclusively on the weighing devices, so that a load on the mounting plate acts particularly effectively on the weighing devices. As a result, a particularly detailed detection of the change in weight can be detected, as a result of which a two-dimensional mapping of the cooking vessels set up on the mounting plate can be carried out particularly accurately. The mounting plate is preferably located directly or indirectly on the weighing devices.

Particularly preferably, the weighing devices are arranged on opposite sides of the hob or the frame device, so that a particularly effective and accurate weight shift or a change in weight on the hob or on the mounting plate can be determined.

According to the invention, the mounting plate is assigned at least one cooking vessel identification device, whereby this is to be understood in particular as meaning that the cooking vessel identification device is part of the cooking field and / or is formed as a separate component. In this case, for example, a pot position can be detected on the mounting plate via such a cooking vessel identification device. But it is also useful pot detection possible in which the nature of the pot and in particular the size of the pot is detected. In particular, the diameter of the pot bottom can be recognized. Furthermore, depending on the configuration of the cooking vessel identification device, it can also be recognized how the filling level of the cooking vessel is and / or whether, for example, a lid is placed on the cooking vessel or not.

Preferably, the cooking vessel identification device comprises at least one induction coil or at least one induction coil of a heating device. In this case, a pot position detection or the recognition of the size of the pot or the pot bottom can be detected on the mounting plate by a phase shift in the induction coils.

In other advantageous embodiments, the cooking vessel identification device can also be provided alone or in addition by an optical recognition device such as a camera or the like. A camera can be arranged, for example, above the cooking field device, in which case in particular the integration a camera in an arranged above the cooking field device hood can be advantageously used. About a camera can be detected in a cooking vessel preferably both the position of cooking vessels on the footprint and the pot size, an overlaid lid and / or the level height.

In expedient developments, the cooking vessel identification device can also be integrated into the operating device of the cooking field device. Then, for example, a user can set on the operating device, which uses a cooking vessel. Thus, the hob field information such as pot size, pot type, pot diameter or other parameters can be supplied, which are necessary for controlling a cooking process via the weight sensor.

The cooking field device according to the invention offers many advantages. By means of the weighing devices and the cooking vessel identification device integrated into the cooking field device, a particularly advantageous support of the user during a cooking process can be ensured. In particular, a cooking assistant can be made available to a user, as described in detail below for the method according to the invention for operating a cooking field device.

The frame device preferably comprises at least two mold sections for receiving or fastening respectively at least one weighing device. In this case, such mold sections in particular provide predetermined areas at which the weighing sensors are provided. So predefined locations can be specified, for example, in a rectangular frame means six mold sections can be provided. Then, for example, in each corner or near the corners of a mold section and be provided in the middle of the two longitudinal sides of a mold section. Thus, as needed, at least two or even more weighing devices can be positioned to receive the mounting plate.

Particularly preferably, three weighing devices are provided, which are arranged in particular in the form of an equilateral triangle. If only two weighing devices are provided, a weighing device is arranged in particular on one side of the frame device and a weighing device on the opposite side of the frame device.

By using at least three weighing devices, which are then preferably arranged in the shape of an equilateral triangle, a two-dimensional map of the cooking vessels can be generated on the mounting plate, whereby weight changes on the mounting plate can be accurately detected. So can also when using several cooking vessels on the hob field a weight change associated with a particular cooking vessel.

In the case of small hobs, for example a tabletop appliance with only one cooking zone, it is also possible to use only one weighing device. Here, load cells can be used, which compensate for the moments occurring in unbalanced load.

By evaluating the compensation of the unbalanced load, it is possible that even with two weighing devices or even with only one weighing device, a two-dimensional map of the cooking vessels can be generated on the mounting plate. The inventive method is particularly suitable for operating a cooking field device, as described above. In this case, weight is detected by means of the weighing devices and a cooking vessel identification by means of the cooking vessel identification device. About a weight detection and the cooking vessel identification conclusions about the state of a cooking vessel and / or about the state of at least one cooking process are drawn in at least one cooking vessel.

A state of a cooking vessel is understood in particular whether a lid is placed on the cooking vessel or not. Furthermore, under a state of the cooking vessel, inter alia, understood in particular whether the cooking vessel is moved on the mounting plate, is raised, is tilted, whether in the cooking vessel is stirred and / or what is used for a cooking vessel.

Under a state of a cooking process in a cooking vessel is understood in particular according to the invention that it is determined whether, for example, a boiling point has been reached or whether a liquid boiling in a cooking vessel.

A boiling impression is the boiling behavior, in particular with respect to the density of the supplied heat output to understand. At low power density, few boiling bubbles form on the bottom of the pot, the boiling impression is weak. A weak impression of boiling is, for example, described as "weakly cooking" or "quietly cooking". At high power density, many boiling bubbles form on the bottom of the pot, which possibly combine to form large vapor bubbles, the boiling impression is strong. A strong impression of boiling, for example, with "strong cooking" or "bubbly cooking" described. To record the boiling impression, it is necessary to determine the pot size or the cross section of the cooking vessel. The amount of power supplied, the weight loss by evaporation of liquid or the weight loss rate, the time and the boiling pressure can be set by calculations in such ratios and derived from each other. For example, can Calculates after which time a certain boiling impression occurs. It is therefore also possible according to the invention to regulate the long-term to a certain boiling impression.

According to the invention, the power of the heater is controlled as a function of the power density. This makes it possible to obtain a certain impression of boiling. The foodstuff in the fluid as a disturbance variable and heat sink is intrinsically taken into account in the method according to the invention and the device according to the invention.

That the control device controls the supply of heating power to regulate the boiling pressure as a function of the target boiling impression can be provided according to a possible embodiment, that the control device controls the supply of heating power to regulate the boiling pressure as a function of the target boiling impression.

Particularly preferably, the ascertained data for weight recognition and the cooking vessel identification are further processed by a control device or an electronic control unit of the cooking field device and used to control the heating devices of a particular cooking surface. Thus, a particularly accurate and advantageous cooking assistance for a user can be provided.

The method according to the invention offers many advantages. In particular, the weight sensors and a position detection of a cooking vessel and / or the recognition of a type of cooking vessel and / or cooking vessel can be used to effect a particularly accurate or exact control of the heating devices for the corresponding cooking area.

In addition, certain actions can be automatically detected by the cooking field device. For example, can be detected by the weight sensor together with the cooking vessel identification, whether a lid is placed or not. In addition, cooking can be regulated particularly precisely, and the cooking field device can continue to control a cooking process so precisely that emissions and energy are saved. In addition, the addition of food and the heat demand of certain foods can be detected, whereupon the performance can be adjusted continuously and optimally.

In conventional methods, the distinction of individual cooking vessels is possible, if at all, only with great difficulty. Furthermore, for example, the structure-borne noise is often measured for the boiling point detection, which, however, means that lower power can not be monitored. These disadvantages are avoided by the cooking field device according to the invention and a user is provided with a particularly comfortable cooking assistance.

Preferably, at least one movement parameter is determined. In this case, the movement of a cooking vessel or the speed, the acceleration, deceleration, the path length, the direction and / or the rotation is understood according to the invention as a movement parameter. Thus, a movement parameter can preferably be determined solely by shifting the weight of a cooking vessel or together with the cooking vessel identification. Then it can be recognized, among other things, whether a pot is moved or moved and where it is moved. Furthermore, it can also be recognized whether a stirring movement is carried out in a pot.

Suitably, the weight is determined continuously for all arranged on the mounting plate cooking vessels, so that the cooking process can be controlled in each cooking vessel over the course of weight. In this case, a continuous determination is understood in particular to mean that so many values are measured that a sufficiently accurate weight course is determined.

Particularly preferably, at least one movement of a cooking vessel is converted into at least one control signal. In this case, a specific movement is determined or derived in particular from at least one movement parameter. By converting a particular motion into a control signal, a particular action can be taken for a particular motion. For example, the power of at least one heater may be changed or issued. In addition, it is also possible for an extractor hood arranged above the cooking hob device to be operated differently in terms of performance depending on the movement. For example, in the case of rapid stirring movements, it can be concluded that increased steam production takes place in a cooking vessel. Then the power of the hood can be increased. Even by recognizing the lifting of a lid, the hood can be operated adjusted in performance or even turned on.

In suitable embodiments, the control of at least one heating device takes place via the detected state. Thus, preferably, the power of the heating device can be continuously adapted to the currently required heat requirement. As a result, emissions and energy can be effectively saved. Also, a boiling or reducing can be achieved by means of a control of the heater with respect to a detected state advantageous.

ṁ

Wassermenge pro Zeit $\left[\frac{\mathit{kg}}{s}\right]$

P

zugeführte Wärmeleistung [kW]

ΔH

Verdampfungsenthalpie $2257\left[\frac{\mathit{kJ}}{\mathit{kg}}\right]$

In preferred embodiments, boiling point detection is carried out in at least one cooking vessel. This is done in particular taking into account the weight detection in connection with the cooking vessel identification. The weight of one Gargefäßes is preferably measured substantially continuously during a cooking process thereto. In particular, so many measurement points are recorded that a weight profile can be reliably determined. When a liquid such as water in the cooking vessel has already reached boiling temperature, the temperature of the liquid remains constant, although energy is supplied. All supplied energy is converted into evaporation. It follows that the cooking vessel loses weight, in proportion to the power supplied. In addition, a boiling point can be effectively detected. In the case of water, the weight reduction, for example, at 3.3 kW heating power is approximately 87.7 g / min and at 1 kW approximately 26.6 g / min. The weight loss can be determined using the following formula: $$\dot{m}=\frac{P}{\mathrm{\Delta }H}$$

m '

Amount of water per time $\left[\frac{\mathit{kg}}{s}\right]$

P

supplied heat output [kW]

Δ H

evaporation $2257\left[\frac{\mathit{kJ}}{\mathit{kg}}\right]$

For low boiling, for example, this is about 3.7 W / cm ² . For average boiling in about 5.2W / cm ² and for strong boiling about 8.2 W / cm ² . The information about the footprint of the pot is preferably determined by means of the cooking vessel identification device. As a guideline for weight loss for low boiling, for example, a weight loss of about 0.1 g / min per cm ² pot bottom, for medium boiling of about 0.14 g / min per cm ² and for heavy boiling 0.21 g / min per cm ^{2 are} assumed. For a small pot of 14 cm diameter and low boiling, this means a weight change of 16 g / min. Measurements with a balance have shown that you can regulate with a resolution of 1 g cooking, which are far below the range where Siedigeräusche are audible. If the boiling water is now supplied with cold food, this can be seen in the absolute weight change of the pot, but also in the weight change per time. Ascending vapor bubbles condense on the cold food and the pot loses less weight at constant power. Similarly, the boiling intensity decreases because not so many vapor bubbles reach the surface. The control then increases the power until the desired weight loss per time is reached again. About the detection of a too rapid decrease or shift of weight and overcooking liquids can be detected, since then the weight decreases faster than it corresponds to the amount of heat supplied, or is displaced into an area outside the Topfausstellfläche. For the latter, the detection of the displacement of the weight is possible by means of the identification device.

It is preferably recognized in at least one cooking vessel as a state whether a lid rests or not and or whether a level change is made. And a level change can be understood in particular the refilling of liquid and / or the reduction of liquid.

It is particularly preferred to detect via the control of the heating device and the weight recognition whether a lid rests on a cooking vessel or not. For example, the heater can be switched off briefly. This is followed by a review of how weight reduction progresses. If there is a lid on the cooking vessel, rising steam will condense on the lid and run back into the cooking vessel. If there is no lid, more steam will escape from the pot and the weight loss will be greater. After detecting whether a lid rests or not, the power of the heater can be adjusted again to the power provided for the cooking process.

In expedient developments, the weight loss of a cooking vessel is compared with the predetermined weight loss for the power used. If the weight of the cooking vessel decreases too quickly, this can be attributed to the overcooking of a liquid.

Further advantages and features of the present invention will become apparent from the embodiments, which are explained below with reference to the accompanying figures.

Figur 1

eine rein schematische Darstellung einer erfindungsgemäßen Kochfeldeinrichtung in einer perspektivischen Ansicht;

Figur 2

eine rein schematische Darstellung einer erfindungsgemäßen Kochfeldeinrichtung in einer Ansicht von oben;

Figur 3

eine rein schematische Darstellung einer erfindungsgemäßen Kochfeldeinrichtung in einer Seitenansicht;

Figur 4

eine rein schematische Detailansicht von Bereich B in Figur 3; und

Figur 5

ein rein schematischer Gewichtsverlauf eines Gargefäßes während eines Garvorgangs.

In the figures show:

FIG. 1

a purely schematic representation of a cooking field device according to the invention in a perspective view;

FIG. 2

a purely schematic representation of a cooking field device according to the invention in a view from above;

FIG. 3

a purely schematic representation of a cooking field device according to the invention in a side view;

FIG. 4

a purely schematic detail view of area B in FIG. 3 ; and

FIG. 5

a purely schematic weight profile of a cooking vessel during a cooking process.

In FIG. 1 is purely schematically illustrated a cooking field device 1 according to the invention, which is formed in the embodiment shown as a cooking field device 1 for installation in a countertop 100.

The cooking field device 1 in this case comprises a housing device 2, which is used in the embodiment shown in a corresponding recess in the work surface 100. In the housing device 2, among other things, the power electronics and in the embodiment shown, several inductors 7 a heater 8 are provided, which can be heated on the cooking field device 1 outstanding cooking vessels.

For setting up cooking vessels on the cooking field device 1, a mounting plate 4 is provided, which is provided in the embodiment shown by a Ceranglasscheibe 9. This mounting plate 4 rests on weighing devices 5, which are fastened to a frame device 3. As a result, the force acting on the mounting plate 4 force can be accurately determined by the weighing devices 5.

Furthermore, it is indicated that four hotplates 10 are provided on the mounting plate 4, of which two cooking zones 10 are shown purely schematically in the illustration shown.

Furthermore, the cooking field device 1 comprises a cooking vessel identification device 50, which is integrated in the cooking field device 1 in the exemplary embodiment shown. In this case, the cooking vessel identification device 50 is provided by the inductors 7 of the cooking field device 1 in the embodiment shown. By phase shifts in the inductors, both the pot position and the pot size can be optimally determined.

By evaluating the data of the weighing devices 5 or the weighing sensor and the cooking vessel identification device 50, a very detailed two-dimensional map of the mounting plate 4 or the weight distribution on the mounting plate 4 can be determined. Thus, for example, a change in weight can be determined very accurately even when standing up several cooking vessels for each cooking vessel on the weight sensor and the cooking vessel identification.

In FIG. 2 is the in FIG. 1 shown cooking field device 1 shown in a purely schematic view from above. Again, you can see the the frame device 3, to which the weighing devices 5 are attached. The mounting plate 4 rests on the weighing devices 5 in such a way that an evaluation of the forces acting on the mounting plate 4 can take place via the weighing devices 5.

In this plan view, it can further be seen that a plurality of mold sections 6 are provided in the frame device 3, by way of which a contact with the weighing devices 5 can or should be produced. In the illustrated embodiment, six mold sections 6 are provided, three of which are provided on one longitudinal side 11 and three on the opposite longitudinal side 12.

Depending on the design of the cooking field device 1 and depending on the desired accuracy, different numbers of weighing devices 5 can be integrated into the cooking field device 1. In particular, at least two weighing devices 5 are provided, which are then preferably arranged on different longitudinal sides 11, 12.

In the embodiment shown, three weighing devices 5 are provided, two of which are arranged on the longitudinal side 11 and a weighing device 5 and the other longitudinal side 12. In this case, the weighing devices 5 are provided or arranged or fixed in the mold sections 6 such that a substantially equilateral triangle is formed by the weighing devices 5. This is indicated purely schematically by the dashed lines.

About such an arrangement of the weighing devices 5 in the manner of an equilateral triangle, the change in weight can be determined on the mounting plate 5 positionally accurate. For example, it can be determined by the weighing sensor alone at which point on the mounting plate 4 a weight change takes place.

In conjunction with the cooking vessel identification device 50, this change in weight can for example be assigned to a specific cooking vessel, wherein a very concrete evaluation of the change in weight can be made by the combination of weighing sensor and cooking vessel identification.

If, for example, a weight relief is detected at a certain point on the mounting plate 4, it can be recognized, for example, by the cooking vessel identification device 50, which is made available here by the inductors 7 of the cooking field device 1, that the weight is relieved at an edge region of the cooking vessel. For example, it can be concluded that the weight is released by a tilting movement of the pot by lifting a handle of the pot.

In FIG. 3 is purely schematically shown a side sectional view of a cooking field device according to the invention. The dashed boxes above and below the cooking field device 1 indicate that the vessel identification device 50, depending on Embodiment of the cooking field device 1 may be assigned and is provided for example by inductors 7.

In other embodiments, the cooking vessel identification device 50 can be associated with the cooking device 1 or the setting plate 4 as before, wherein the cooking vessel identification device 50 is then integrated into the operating device of the cooking field device 1, for example. So it is according to the invention also possible that the cooking appliance identification is done manually. Then, for example, set a user on the control device, which he uses a cooking vessel, so that, for example, the diameter of the pot bottom is known. Also, a particular cooking location could then be assigned to the cooking vessel to determine the position of the cooking vessel on the mounting plate, if several cooking vessels are used. Such information may for example be stored in the operating device and / or the control device or be added by a user manually.

By the dashed box above the cooking field 1 is indicated that the cooking vessel identification device 50 may also be configured as a separate component, the cooking appliance identification device 50 then, for example, at least one image capture device 51 such. B. includes a camera 52. Such an external cooking vessel identification device 50, for example in the form of a camera 52, can advantageously be integrated, inter alia, in an extractor hood above the cooking field device 1.

Also, by means of such a cooking device identification device 50 in the form of an image capture device 51, an effective recognition of certain cooking vessels can be achieved. Thus, among other things, the pot position and the Topfart different cooking vessels on the cooking field 1 or on the mounting plate 4 can be determined exactly. In addition, it can furthermore be detected quickly and simply via such an optical cooking vessel identification device 50 whether a lid rests on a cooking vessel or not and / or how the filling level in a cooking vessel is.

Thus, for example, can be optimally controlled by a level detection in a particular cooking vessel, the reduction of liquids. Then, for example, the thickening or reducing of sauces via an evaluation of the data of the weighing devices 5 and the cooking vessel identification device 50 is optimal and depending on the design of the cooking field device optimally controllable or regulated.

In FIG. 4 is purely schematic an enlargement of detail in FIG. 3 shown with "B" section. Here again is shown purely schematically how a weighing device 5 is arranged in a mold section 6 of the frame device 3.

With such a trained cooking field device 1 a user can be provided a particularly comfortable cooking assistant. For example, automatic programs may use the data of the weighing devices 5 and the cooking vessel identification device 50 to control cooking processes.

In FIG. 5 is shown purely schematically the course of weight over a certain portion of a cooking process over time. It is shown in the curve shown how boiling point detection can be provided by means of the cooking field device 1 according to the invention using the weighing devices 5 and the cooking vessel identification device 50.

Thus, using the determined data of the weighing devices 5 and the cooking vessel identification device 50, a weight profile of a certain cooking vessel is monitored on the positioning plate 4. At time t0, the weight of a particular cooking vessel is composed of the weight of the cooking vessel and the food in the cooking vessel, in this case water.

The cooking vessel is heated by a heater and the weight does not change initially, since the liquid in the cooking vessel must first heat up. At the time t1, a lid was placed on the cooking vessel, which can be recognized here by increasing a specific weight, when a certain cooking vessel was detected by the cooking vessel identification device 50 and the weight of the lid for this cooking vessel is known. Otherwise, the resting of a lid can also be determined experimentally as described later.

In the course of the water begins to evaporate, whereby the weight of the cooking vessel begins to decrease. A boiling point can be recognized by the fact that the weight loss per time is constant.

At time t2, the lid was removed again from the cooking vessel, which is detected by a specific weight reduction. At time t3, cold liquid was replenished into the cooking vessel, wherein at the time t4, the lid was placed again on the cooking vessel.

By adding cold liquid, the pot contents no longer boil, leaving the weight substantially constant. From the time t5, a weight loss per unit time is again detectable, wherein a boiling point can be recognized again by the fact that the weight loss per time constant.

Generally, when operating such a cooking field device, the reaching of a boiling point can be effectively detected. The weight of a cooking vessel is measured substantially continuously during a cooking process. In particular, so many measurement points are recorded that a weight profile can be reliably determined.

When the liquid in the cooking vessel has already reached boiling temperature, the temperature of the liquid remains constant, although energy is supplied. All supplied energy converted into evaporation. It follows that the cooking vessel loses weight, in proportion to the power supplied.

ṁ

Wassermenge pro Zeit $\left[\frac{\mathit{kg}}{s}\right]$

P

zugeführte Wärmeleistung [kW]

ΔH

Verdampfungsenthalpie $2257\left[\frac{\mathit{kJ}}{\mathit{kg}}\right]$

In the case of water, for example, at 3.3 kW heating power, this is approximately 87.7 g / min and at 1 kW approximately 26.6 g / min. The weight loss can be determined using the following formula: $$\dot{m}=\frac{P}{\mathrm{\Delta }H}$$

m '

Amount of water per time $\left[\frac{\mathit{kg}}{s}\right]$

P

supplied heat output [kW]

Δ H

evaporation $2257\left[\frac{\mathit{kJ}}{\mathit{kg}}\right]$

In conventional cooking hobs, a user often rates the severity of a boiling process from bubbling in the cooking vessel, e.g. weak, medium or strong cooking. In order to produce a uniform impression of the weak cooking for different pot diameters, the area of the pot bottom must be taken into account. A larger pot diameter is more power than a smaller one to produce a consistent impression of low boiling. The power density and thus the weight loss per unit time and area remains constant.

For low boiling, for example, this is about 3.7 W / cm ² . For average boiling in about 5.2W / cm ² and for strong boiling about 8.2 W / cm ² . The information about the surface of the pot is thereby determined in the cooking hob device 1 according to the invention by means of the cooking vessel identification device 50. To determine the pot size, the inductors 7 of the heating device 8 are used in the illustrated embodiment. From the electrical variables of one or more induction generators is via a Phase shift of the pot diameter determined. Thus, the cooking vessel identification device 50 is integrated in the cooking field device 1 in the embodiment shown. In other embodiments, the cooking vessel identification device 50 can also be provided as a separate component. For example, the cooking vessel identification device 50 may comprise at least one image capture device 51, which is provided by a camera 52, for example. A camera 52 may preferably be integrated in an extractor hood above the cooking field device.

This means that in order to set the boiling pressure in a pot filled with water, only the diameter of the bottom of the pot is needed and the desired power density could be adjusted via the power of the hotplate. Unfortunately, this controlled operation does not work if there is a time-variable heat sink in the pot, for example due to a food to be heated. Part of the vapor bubbles condenses on the food and less vapor bubbles reach the surface, which means that the boiling impression changes.

This disturbance can be taken into account if, according to the invention, the weight loss per time is evaluated, since the time-variable heat sink is included in this measured variable. Food condensing steam does not leave the pot and the weight loss per time decreases. The power can then be continuously adjusted to the heat demand of the food until the required weight loss for the desired boiling impression per time and area is restored.

As a guideline for low boiling, for example, a weight loss of about 0.1 g / min per cm ² pot bottom, for medium boiling of about 0.14 g / min per cm ² and for heavy boiling 0.21 g / min per cm ^{2 be} accepted.

For a small pot of 14 cm diameter and low boiling, this means a weight change of 16 g / min. Measurements with a balance have shown that you can regulate cooking with 1 g resolution, which are far below the range where Siedigeräusche are audible.

If the boiling water is now supplied with cold food, this can be seen in the absolute weight change of the pot, but also in the weight change per time. Ascending vapor bubbles condense on the cold food and the pot loses less weight at constant power. Similarly, the boiling intensity decreases because not so many vapor bubbles reach the surface.

The control then increases the power until the desired weight loss per time is reached again. If a lid is placed on the pot, this can also be determined by the absolute weight change, since the lid has a certain weight. As with the addition of a cold food, the weight change will initially be smaller as steam condenses on the lid. The regulation also compensates for this.

The information about the presence of the lid may e.g. be used to reduce the cooking performance, to avoid overcooking. If the pot has been placed on the hob with its lid on and an undefined amount of food, it can not be determined by absolute change whether the lid is on the pot.

In that case, it is possible to briefly interrupt the power supply after reaching the boiling point. For a pot with a lid, the absolute weight remains constant because the lid avoids evaporation. For a pot without a lid, the water will evaporate on the surface and the weight will continue to decrease. At the same time, the water temperature drops with the weight. This makes it possible to detect by measurement, whether the lid rests on the pot or not. If a lid is placed on the pot, the rising vapor will condense on it and the condensate will run back into the pot. The weight change is in a cooking vessel with lid thus different than a pot without a lid.

Generally, in a heating process, all energy is first used to heat the water. Only when the water has reached a certain temperature does the water begin to evaporate. Only a part of the heat energy is used to heat the water. The temperature curve of the water then becomes flatter.

With increasing warming more and more steamy water leaves the pot, the temperature curve becomes ever flatter until the boiling temperature is reached. Then the curve is horizontal.

For the weight of the pot, this means that it is constant at the beginning and then decreases more and more, until at the boiling point the weight loss per unit of time becomes constant. In this way the boiling point can be recognized.

The efficiency of the cooking process can be increased by limiting the weight loss per unit of time to a maximum value. In this way, a percentage of more energy is put into the heating of the water, without the heating process is slower.

Due to the positionally accurate determination of the weight loss, the cooking behavior in individual cooking vessels can thus be determined on the mounting plate 4. Thus, it is possible that, as described above, a boiling point detection for individual cooking vessels is made. In other examples of use, cooking may also be optimally controlled, or the reduction of liquids monitored, controlled and controlled.

In general, it is possible according to the invention that the heat input or the heating power for certain cooking vessels is optimally adapted to the current state of the cooking vessel content by means of the inventively designed cooking field 1, whereby emissions and energy can be saved.

Furthermore, it is possible by the cooking vessel identification device 50 and the weighing sensor to detect certain movements in or on a cooking vessel and to convert them into at least one control signal. Thus, it is possible, for example, that a stirring motion can be detected in a pot, wherein the weight sensor is so sensitive that even the direction of the stirring motion can be detected.

Furthermore, the displacement and / or the rotation of a cooking vessel can be detected, whereby certain actions can be initiated by such movements. For example, it can be detected by the cooking vessel identification device and the weighing sensor, whether a cooking vessel is removed from a particular cooking area. Then the previously used hotplate can be turned off, for example. Furthermore, strong stirring movements and / or the removal of a lid can be detected, which, for example, external devices such as a cooker hood can be operated changed in performance.

In another application example, in a frying process, high power densities are used to achieve the desired browning while avoiding dehydration. Then, when a steak is removed from the pan, the power density can be reduced by recognizing the weight reduction before the reduced heat capacity manifests itself in a temperature increase.

For example, overcooking liquids can also be detected by overly rapid weight loss because then the weight decreases faster than corresponds to the amount of heat supplied.

LIST OF REFERENCE NUMBERS

1

Hob unit

2

housing means

3

frame means

4

mounting plate

5

weighing System

6

mold sections

7

inductor

8th

heater

9

Ceranglasscheibe

10

cooking

11

long side

12

long side

50

Gargefäßidentifikationseinrichtung

51

Image capture device

52

camera

100

countertop

Claims (13)

Cooking field device (1) comprising at least one mounting plate (4) configured to receive at least one cooking vessel, at least one heating device (8) configured to supply heating power to a cooking vessel positioned on the positioning plate (4) for heating a fluid in the cooking vessel, and at least one, in particular at least two weighing devices (5) which are configured, in the installation position of the cooking field device (1), to detect at least one weight force acting on the setting plate (4),
characterized,
that the mounting plate (4) is associated with at least one Gargefäßidentifikationseinrichtung (50) which is configured to detect the at least one footprint arranged one on the mounting plate (4) cooking vessel. Cooking field device (1) according to claim 1, wherein the cooking field device (1) comprises a control device which is configured to associate the at least one weight force and the at least one set-up surface to a cooking vessel. Cooking field device (1) according to one of the preceding claims, wherein the control device is configured over time to determine a course of change of the at least one weight and the heater (8) as a function of the ratio of the time course of the at least one weight and the footprint to Taxes. Cooking field device (1) according to one of the preceding claims, characterized in that three weighing devices (5) are provided, which are arranged in particular in the form of an equilateral triangle. Cooking field device (1) according to one of the preceding claims, wherein the cooking field device (1) comprises an input device which is configured to detect a user input, in particular a desired boiling impression. Method for operating a cooking field device (1) according to one of the preceding claims, the method comprising the following steps: a) the at least one weight of at least one fluid or at least one cooking vessel with fluid is determined by the weighing devices (5) during the preparation continuously or at certain time intervals or at certain times; b) the at least one fluid is supplied via the heating device (8) heating power; c) the information of the determined at least one weight force is supplied to the evaluation of a control device; characterized in that d) by means of a cooking vessel identification device (50), the at least one footprint of at least one cooking vessel is determined; e) is assigned by means of the control device, the at least one footprint and the at least one weight of at least one heating device (8); f) where
from the time course of the change of at least one weight force and the at least one footprint is closed to a boiling impression of the fluid and / or
the course of a heating level of the fluid is determined from the time course of the change in the at least one weight force and the at least one set-up surface and the boiling pressure of the fluid is determined by determining the course of the heating level; g) and controlled by the control device for influencing the boiling impression, the supply of heating power. Method according to the preceding claim 6, wherein at least one movement parameter is determined. Method according to at least one of claims 6 or 7, wherein at least one movement of a cooking vessel is converted into at least one control signal. Method according to at least one of claims 6 to 8, wherein a user input is detected by means of an input device and at least one of the following steps is carried out: aa) the current boiling impression is set and / or stored in the control device as a target boiling impression; bb) with the user input a predetermined desired boiling impression or a stored desired boiling impression is selected; cc) the control device controls the supply of heating power to regulate the boiling pressure as a function of the desired boiling impression; Method according to at least one of claims 6 to 9, wherein based on the evaluation of the course of the heating level and / or the course of the boiling impression, the supply of the heating power is controlled. Method according to at least one of claims 6 to 10, wherein at least one cooking vessel, a boiling point detection is performed. Method according to at least one of claims 6 to 11, wherein in at least one cooking vessel, the state of the cooking vessel is detected and / or is detected by the control of the heater and the weight detection, whether a lid rests on a cooking vessel. Method according to at least one of claims 6 to 12, wherein the change in the weight of a cooking vessel is compared with the predetermined change of the weight for the power used.

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