EP1580487A1 - Electronically controlled hob with a plurality of cooking plates and method for its operation - Google Patents

Abstract

A glass ceramic cooking hob unit (11) has multiple cooking zones (14) heated by inductive heating elements (16) having capacitive sensing elements (22) which sense the existence of a cooking vessel (25). A single heating control switch (21) operates on any cooking zone selected by the user (27).

Description

Field of application and state of the art

The invention relates to a hob with several cooking zones according to the The preamble of claim 1 and a method for operating such Hob, which may be electronically controlled in particular.

For the power setting of, for example, hobs with touch switches It is known, for each hotplate, a so-called selection / select buttons provide, as well as a plus and a minus button for changing the power setting. By operation one hotplate is selected in each case one selection key. In this selected state can be by means of the plus or minus button the performance to be changed. Such a change in performance is only possible if a hotplate has been previously selected. On this way it is possible to reduce the number of plus / minus buttons as to provide for the entire hob only a single such pair is and only one selection button per cooking area.

Efforts have been made to reduce the number of necessary ones To further reduce touch buttons. It is for example in DE 102 11 047 A describes a cooking place by setting up a To select a cooking vessel. A so-called pan detection sensor recognizes the placed cooking vessel and puts this cooking place in the selected state, so that after putting the cooking vessel a power adjustment is possible. This method is suitable but obviously only for the first power setting at the beginning the operation of the hob. For subsequent performance settings it is not suitable anymore.

Task and solution

The invention is based on the object, an aforementioned Cooktop and an aforementioned method to create, with which the problems and disadvantages of the prior art avoided and cooking hobs and their operation further developed can be, in particular a selection of a cooking place at any possible operating conditions can be improved.

This task is solved by a cooktop with the characteristics of the Claim 1 and a method having the features of claim 8. Advantageous and preferred embodiments of the invention are the subject the further claims and are explained in more detail below. The wording of the claims is by express reference to the content of the description. The features of the invention Procedure in different versions also from the following description in corresponding Wise.

According to the invention it is provided that such a hob a selection device for each hotplate, with which this selected can be used to prepare an operator-initiated or desired change of the operating state of the cooking area. Prefers is such a change in the operating state is a change of Power. However, it can also, for example, in a so-called Multi-circuit hotplate an additional heating circuit switched on or off become. The selection device has an actuation sensor on or such a device. The actuation sensor is designed such that he has a touch of a cooking vessel on this cooking place an operator recognizes. Such a touch evaluates the hob as a selection of this cooking place, depending on an operator-dependent Change of the operating state of the hob by more Enable operator input.

This means in one possible embodiment that a touch or a touch of a cooking vessel detected by the hob is assigned and this cooking vessel or the relevant cooking area becomes. From the point of view, this is taken as the selection of the cooking area, in order to depend on known methods according to the operating condition to change this cooking place. So can on more input elements or omitted controls such as the aforementioned select buttons become. Furthermore, an instinctive selection of a cooking place by touching the cooking vessel on top. After all it has proved in the context of investigations of this invention, that in many cases a touch of the cooking vessel, for example when lifting the lid or while stirring with the same time Clinging takes place. These actions follow in practice often changes at least in the power setting of the hotplate, because the operating state is detected as not desired. Consequently the selection of cooking zones to be changed happens more or less automatically or by itself. In addition to the savings effect of a so-called selection button In many cases, an operator may even still have to select spared yourself.

As an actuation sensor can basically different types of Sensors are used, which are the touching of the cooking vessel detect. This can be a so-called capacitive sensor, as he For example, in DE 42 24 934 A is described. Alternatively it can be an inductive sensor, which for example have coil shape can. Such an inductive sensor is for example in DE 196 03 845 A discloses. Furthermore, it is possible that an actuation sensor detects a slight movement of the cooking vessel, for example a slight back and forth by a few inches. Such a Operation may, in addition to usual, prescribed methods also by optical sensors or the like above the hob as well Sensors for vibration or acceleration under the hob be recognized.

In a preferred embodiment of the invention, an actuation sensor at the same time a so-called cooking vessel detection sensor be known, also known as pan detection. Through this dual function The number of sensors to be provided can be reduced. In this Thus, it is advantageous if, according to the same method of measurement, both the presence of a cooking vessel as well as a touch of the same is detected. The different modes can, for example to run alternately.

It is advantageous if the actuation sensor is below the hob or a hob plate is arranged. So he disturbs the appearance not, is easy to install or provide on the hob and is also from impairment such as pollution or like protected. Such a hob plate is advantageous made of glass ceramic, which is permeable to the aforementioned sensors.

In one embodiment of the invention, even a plurality of actuation sensors per selection device or per hob provided be. These are advantageously arranged at different positions. Thus, an adaptation to possible different sizes of a Cooking vessel done on this hotplate, for example, at a More district heating. The multiple actuation sensors can do this arranged in cooperation with possible sizes of the cooking vessel so be that depending on the size of the cooking vessel respectively only one actuation sensor responds to touching a cooking vessel.

Furthermore, it can be provided according to the invention that for the operator-dependent Change the operating state of the cooking area, for example a setting of a power, common controls are provided, which their assigned function exactly have the same for all cooking zones. Advantageously, these are a so-called Plus and a minus control, with which the power is infinitely variable or increased or decreased in stages. Will one Hob selected by touching the cooking vessel, so are the common controls on this hob aligned or change with their function the operating state of this Cooking.

It can be provided that by appropriate means a Feedback is issued to an operator, which is a Selection state or a change of the operating state of a Cooking plate indicates. For example, if a selection is detected as such, a feedback can be sent to the operator. This can be visual or acoustically.

Furthermore, to increase the ease of use and operating safety be provided that the selection of a cooking place for a certain time is maintained as such, so to speak the operator To give time to change the operating state. Such Time should be in the range of several seconds, for example maximum 10 seconds. Thus, operating errors can be due to too long Selection times are avoided.

In a further embodiment, it can be provided that the selection of a Hotplate is lifted immediately if an inappropriate operating state entry or selected, for example, another hotplate becomes. Either then this additional cooking is selected or just the selection of the previous ones canceled.

As a further security feature can be provided that only then a selection is recognized as such when a standing on the hob Cooking vessel is touched for a certain time. This time should also in the range of seconds, preferably at least a second. This avoids that at a fleeting touch, which due to their short time actually only may be unintentional, a selection takes place.

Furthermore, it can be provided that in the event that two cooking vessels are touched at the same time, so either the touch has occurred at the same time or at least overlaps in time, no selection is considered. In this case can not It is important to distinguish between which hob actually selected shall be. In such a case, for example, a corresponding Signal in the manner of a fault or danger signal to a Operator be issued.

Is a so-called inductive cooking vessel detection sensor as an actuation sensor used and evaluated with oscillating circuit detuning, so it can be operated at a higher frequency to one Touch the cooking vessel to recognize. For example, in the aforementioned Types of sensors may have this frequency in the range of 2 MHz to 30 MHz, preferably between 8 MHz and 20 MHz. This is due to the applied evaluation method of frequency measurement. To the extremely small change in the resonant circuit capacity of to be able to evaluate about 5 pF by touching the cooking vessel is it is necessary to keep the resonant circuit close to the natural resonance of the resonant circuit To operate sensors. From stray capacity of the cooking vessel detection sensor, about 50 pF to 200 pF, and a small resonant circuit capacity, about 50 pF to 220 pF, and the inductance of the cooking vessel detection sensor, about 300 nH to 800 nH, with a mounted cooking vessel results in a high resonance frequency.

These and other features go beyond the claims as well from the description and the drawing, the individual Characteristics in each case alone or in the form of sub-combinations in one embodiment of the invention and on others Be realized and beneficial and protectable areas Represent embodiments for which claims protection here becomes. The subdivision of the application into individual sections as well as intermediate headings restrict the statements made thereunder not in its generality.

Brief description of the drawing

An embodiment of the invention is in different variants 1 schematically illustrated and will be described in more detail below. 1 shows a schematic oblique view of a cooking hob according to the invention with four burners and one as a selector serving cooking vessel detection.

Detailed description of the embodiment

In Fig. 1, a hob 11 is shown schematically in an oblique view, in to which the invention is realized in two variants. The stove top 11 has a glass ceramic plate 12 which forms the surface. However, this could also consist of other materials. On the Glass ceramic plate 12 are provided a plurality of cooking zones 14a-d, as in a conventional hob, namely approximately equally distributed. she can by appropriate markings on the top of the glass ceramic plate 12, for example, corresponding imprints or the like, be marked. Of course it is here too possible to provide so-called switchable multi-circuit cooking zones, be it in round or oblong shape.

Under each hotplate 14a-d, a heater 16a-d is provided in each case. These are so-called 12 especially in glass ceramic plates Radiant heaters. It could alternatively also induction heaters used, the type of heating used for the invention plays no role in this regard. Each of the heaters 16a-d is controlled via a controller 18 and according to a selected Cooking or power level powered. These are the circuit breakers 20a - d are provided, namely for each heater 16 a. By means of touch switches 21, which on the right edge of Glass ceramic plate 12 are arranged and corresponding markings On the top of the plate may be the operation of the Hob 11 done, for example, as a setting of a cooking or Power level for the heater 16 a hob 14. These are the touch switch 21 with plus and minus symbols to increase or reduction of the performance. The touch switches 21 can be designed for example as a capacitive touch switch and so-called touch buttons or switches. In addition to capacitive Functional principles can also be used optical or other as well as mechanical switches or the like are possible. By placing a finger 27, the touch switch 21 can be operated according to their function.

Furthermore, located below the cooking areas 14, advantageously between Glass ceramic plate 12 and heater 16, the so-called cooking vessel detection sensors 22a and d. These can be different Form be formed. Under the hotplate 14a is in a variant of the invention a cooking vessel detection sensor 22a is provided which has approximately coil shape and is connected to the controller 18. Such a sensor is described for example in EP 788 293 A, which are expressly referred to in terms of possible realizations becomes. Such a cooking vessel detection sensor 22a is in the Usually used to put a cooking vessel 25 a on the Hotplate 14a to capture and only then a power release on the To allow heating 16a. So can a malfunction of a cooking place or an associated heater without an attached cooking vessel, off which either a risk of burns or at least energy loss would be avoided.

Under the hob 14d are in another variant of the invention two Cooking vessel detection sensors 22d arranged which are not in coil form are formed, but form two individual surfaces, with respect to the size of the hob 14d at the edge, approximately opposite are arranged. These cooking vessel detection sensors 22d can have a capacitive operating principle, as for example from DE 42 24 934 A is known. Although another functional principle used. The purpose, however, is the same, namely the recognition the presence, the training and possibly also the size of one belonging to the cooking vessel detection sensor Cooking place patch vessel.

function

In the following, the function of the hotplate 14a with the coil-shaped inductive cooking vessel detection sensor 22a described become. However, this functional description is expressly not on limits the special design of the cooking vessel detection sensor 22a, but can, either directly or in a corresponding modification, used with other cooking vessel detection sensors especially when working with electromagnetic fields, So are either inductive or capacitive nature.

Since in the illustrated hob 11 according to the invention for power adjustment all cookers 14a-d only the two touch switches 21, a so-called selection, also called selection, take place. This is used to determine which Hotplate 14 in a subsequent process the cooking or Performance level is changed. If a cooking vessel 25 is set up, then recognizes this the cooking vessel detection sensor 22 together with the Control 18. The controller 18 evaluates this as a selection of the corresponding Hotplate 14. This means that subsequent actuation the touch switch 21 for the state of this particular Hotplate 14 and the associated heater 16 applies. This is in itself also in this way from the prior art in the form of DE 102 11 047 known.

But now also some time after setting up the cooking vessel or at any time during cooking, especially with several cooking zones of the hob 11, a change in the cooking or power level of a hotplate 14, this must again to be selected. According to the invention, this is done by that with a finger 27, the cooking vessel 25 is touched. It is emphasized that a displacement of the cooking vessel is indeed possible and possibly the clarity of a selection can underline. Basically, however, it is not necessary because such a move at least to the extent that it is safe from a cooking vessel detection can be detected, it should be so large that it may is considered to be expensive or impractical.

In the context of the invention has been shown that in accordance with precise tuning and evaluation of the signals of the cooking vessel detection sensor 22 can be determined, whether a cooking vessel is touched. For this purpose, metallic cooking vessels are necessary. By the Touching the cooking vessel 25 with one or more fingers 27 is added the capacity of an operator parallel to the resonant circuit capacity. This may be due to the cooking vessel detection sensor signal 22 are detected. To detect this touching of the cooking vessel, it is necessary, the operating frequency of the cooking vessel detection sensor to very high values of for example 2 MHz to 30 MHz, preferably 8 to 20 MHz, to move.

Was about the cooking vessel detection sensor 22 and the controller 18 registers that the cooking vessel has been touched, this is called Selection scored and a subsequent actuation of the touch switch 21 or other state switch then applies exactly to This hotplate, for example, could also be connected to an additional heating zone become.

It may be provided, after actuation of the touch switch 21st relatively quickly delete the selection state of the hob again. Alternatively it can be provided, this state at least for some Seconds still to hold, to a shortly thereafter fast change does not precede a selection process again to have to.

It may also be possible, after selecting a hotplate by touching the adjacent cooking vessel 25 with a finger 27 this Selection state a few seconds, for example 3 to 10 seconds, to maintain. This will give a user enough time after selecting a particular hob their performance or change state.

Will after selecting a hotplate and before pressing the touch switch 21 touches another cooking vessel 25, so changes favorably the selection of the hob as the last pressed or the selection the first operated hotplate is lifted.

Above all, it is provided with advantage in the invention that after recognized Touching a hob 25 a corresponding signal a user is output, either visually or acoustically. It is not necessary while changing the state of the hotplate continue to touch the cooking vessel 25 via the touch switch 21. A single touch, possibly with a minimum required Time span, can be considered sufficient.

Claims (14)

Hob (11) with a plurality of cooking zones (14), on each of which a cooking vessel (25) can be provided for heating therein cooking, with a selection device for each cooking area for selection in preparation for a user-dependent change of the operating condition, characterized in that Selection device has an actuating sensor (22) which is designed such that it detects a touch of a cooking vessel (25) on this cooking point (14) by an operator, the hob (11) as a selection of the hotplate for the operator-dependent change of the operating state the cooking position by further operator input looks. Hob according to claim 1, characterized in that the actuation sensor is a capacitive actuation sensor, wherein it has in particular a sensor surface (22d). Hob according to claim 1, characterized in that the actuating sensor is an inductively operating sensor (22a), preferably in coil form. Hob according to one of the preceding claims, characterized in that the actuating sensor (22) is simultaneously a cooking vessel detection sensor. Hob according to one of the preceding claims, characterized in that the actuating sensor (22) below the hob (11) or below a hob plate (12) is arranged, which preferably consists of glass ceramic. Cooking field according to one of the preceding claims, characterized in that a plurality of actuation sensors (22d) per selection device and per cooking point (14d) are provided at different positions of the cooking position, wherein the plurality of actuation sensors each depending on the size of the cooking vessel (25) can be activated. Hob according to one of the preceding claims, characterized in that it has a plurality of common operating elements (21) for the operator-dependent change in the operating state of the cooking zone (14), in particular the setting of a power of each cooking hob, preferably a plus and a minus control for all hobs, wherein after selecting a hotplate on the actuating sensor (22) by touching a cooking vessel (25), the power of this hotplate is changed by selectively pressing the controls accordingly. Method for operating a cooktop according to one of the preceding claims, characterized in that by touching a cooking vessel (25) placed on a cooking vessel (25), this cooking station is selected for a user-dependent change of its operating state, wherein the change of the operating state by operating further operating elements ( 21) of the hob, in particular as a change in performance. A method according to claim 8, characterized in that after the selection of a hotplate (14) by touching a standing above cooking vessel (25) a feedback is issued to an operator, which is preferably optically and / or acoustically. A method according to claim 8 or 9, characterized in that a cooking point (14) is considered to be selected only if the cooking vessel (25) standing thereon has been touched for a certain time in the range of seconds, preferably at least one second, by an operator is. Method according to one of claims 8 to 10, characterized in that the selection of the cooking point (14) is maintained for a certain time, preferably a maximum of 10 seconds. Method according to one of claims 8 to 11, characterized in that the selection of a hotplate (14) is canceled immediately if another hotplate has been selected by touching a cooking vessel (25) standing thereon. Method according to one of claims 8 to 12, characterized in that with simultaneous or overlapping contact of several cooking vessels (25) on different cooking zones (14) no selection is evaluated, wherein preferably a warning signal is issued to an operator. Method according to one of claims 8 to 13, characterized in that an inductive Kochgefäßerkennungs sensor (22) is used as an actuation sensor, wherein it is preferably operated at a frequency in the vicinity of the self-resonance.

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