EP3297397B1 - Method for operating a cooking hob with multiple heating devices - Google Patents

Description

Field of application and state of the art

The invention relates to a method for operating a hob, this hob having a plurality of heating devices under a hob plate.

From the EP 2211591 A1 It is known that in an induction hob with a large number of induction heating coils as heating devices under a hob plate, those induction heating coils take over the heating of a cooking vessel or its contents that are completely or at least 50% covered by the cooking vessel. If the cooking vessel is moved, for example deliberately into a new position, for example because more space is required on the hob plate or the cooking vessel is disturbing at this point, a previous power level is taken along as a predetermined first surface power density for heating the cooking vessel. The displaced cooking vessel is also heated in the new position with this predetermined first surface power density. This saves an operator the effort of re-entering the previous power level or surface power density for the cooking vessel at its new position.

From the EP 3001772 A1 another induction hob is known. To increase the comfort for an operator, a so-called power move heating mode is described. This is designed to heat a cooking vessel depending on its position in a specific cooking surface area with different heating power densities. This is commonly known as the "Chef Role". The heating of the cooking vessel is reduced when it is pushed from a position at the front of the hob to a position at the rear of the hob. In the front, easily accessible area, rapid parboiling with high power is possible. By moving the cooking vessel backwards, so to speak, out of the direct area of action, the power is automatically reduced as continued cooking with reduced power.

Task and solution

The invention is based on the object of creating a method mentioned at the beginning with which a hob with a hob plate and several or with a plurality of heating devices can advantageously be operated, in particular in the event that a cooking vessel is to be moved on the hob plate and should continue to be heated. This object is achieved by a method having the features of claim 1. Advantageous and preferred embodiments of the invention are the subject matter of the further claims and are explained in more detail below. The wording of the claims is made part of the content of the description by express reference.

It is provided that the hob which is to be operated with the method according to the invention has a hob plate and a large number of heating devices are arranged underneath. The heating devices advantageously adjoin one another and / or are provided in a regular arrangement so that they cover a substantial part of the area under the hob plate, in particular a so-called heating area. Such hobs are for example from the aforementioned EP 2211591 A1 or the DE 102014224051 A1 known.

In the method, the following steps are carried out, it being possible for steps in between. First, a cooking vessel is placed on the hob plate in a first position, the cooking vessel covering at least one heating device. It advantageously covers at least two heating devices in such a way that both heating devices are operated. In a next step, this at least one heating device is operated with a certain predetermined first surface power density in order to heat the cooking vessel or its contents. This predetermined first surface power density is usually entered as a power level when entered manually by an operator on an operating device of the hob, alternatively by means of a remote control for the hob. Alternatively, a first surface power density could also be specified by an automatic cooking program.

In the next step, essentially after any time after setting up the cooking vessel and starting operation of the heating device, the cooking vessel is moved on the hob plate, for example deliberately by an operator, because the current position may be perceived as disturbing or unnecessary. Such a displacement of the cooking vessel must take place by a certain minimum displacement path so that the method runs or makes sense. This can be at least 5 cm, for example. The cooking vessel is then in a second position which differs from the first position in terms of this minimum displacement. The future surface power density with which the cooking vessel is heated is then determined as a function of the previously described, predetermined and currently or previously used first surface power density for the at least one heating device. It is therefore determined with which future surface power density the cooking vessel is heated in the second position. There are at least two cases.

In a first case, the previous heating of the cooking vessel took place with a so-called small area power density as the first area power density. This means that the cooking vessel has been heated with such a small surface power density after it has been set up in the first position until the point in time at which it has been moved to the second position by a certain displacement, namely at least the minimum displacement. Such a small surface power density is advantageously equal to and less than 3.5 W / cm ² , under certain circumstances even less than 3 W / cm ² or 2.5 W / cm ² . 3.5 W / cm ² usually correspond to level 7 as the power level or level on an induction hob.

Heat setting. In this first case, the cooking vessel is also heated at the second position with the previous first surface power density, so it is retained. The heating of the cooking vessel does not change or changes only insignificantly, namely possibly depending on negligible parameters such as the coverage of one or more heating devices. In principle, this should also be independent of whether the cooking vessel is heated by one or more heating devices in the first position or in the second position, because it covers these differently. The aim of the invention is to ensure that in this first case, i.e. when the cooking vessel is previously heated with a small surface power density in the first position, this heating with a small surface power density is also continued in the new second position, in particular is continued permanently.

In a second case, when the heating device was first operated, the cooking vessel was heated with a high surface power density as the first surface power density after it was set up, and this is then reduced, in particular permanently reduced, after the cooking vessel has been moved into the second position. The second area power density here is therefore less than the specified first and large area power density. Such a large area power density can advantageously be greater than the previously mentioned 3.5 W / cm ² or greater than 45% of the maximum area power density as a distinguishing value or limit value. It can also only be present at even higher values, for example at 4 W / cm ² or even only at 5 W / cm ² , that is to say at 50% to 60% of the maximum surface power density. In this second case, the heating power or the surface power density or the power or cooking level is reduced after the shift. The invention has found that, in practice, when the cooking vessel is heated to such a large or very large or even only at the maximum surface power density, a cooking vessel is then moved if an undesired or critical condition is present: for example, water for pasta or water with pasta boiled over in it, or a steak is seared too much in a pan or threatens to burn. In conventional hobs with few heating devices, in which usually only a single heating device, possibly with several heating circuits for size adjustment, is provided for heating the cooking vessel, moving the cooking vessel away from the complete covering of the heating device can result in a clear or complete Reduction of the heating power can be effected. The cooking vessel is, so to speak, removed from the hotplate. In the second case of the invention, this behavior is to be simulated or reproduced, so to speak, which is why in this second case the surface power density is reduced.

In an advantageous embodiment of the invention, a reduction in the area power density in the aforementioned second case, i.e. if a large predetermined first area power density was used at the beginning, to a new or future area power density between 0.5 W / cm ² and 4 W / cm ² or 1.0 W / cm ² and 4 W / cm ² , particularly advantageously between 1.5 W / cm ² and 2.5 W / cm ² . In particular, the area power density can be reduced to or below the limit value described above, from which a distinction is made between either a small area power density or a large area power density. Under certain circumstances, it can also be provided that a reduction in the surface power density takes place even more in this second case, in particular even below the mentioned first surface power density or below the limit value. As a result, a previously described critical or undesired state can be eliminated in any case.

In a further embodiment of the invention it can be provided that the aforementioned small surface power density is even below 3.5 W / cm ² . It can also be only 1.5 W / cm ² or 2.5 W / cm ² , corresponding to a level 5 or 6 as the power level or cooking level.

The minimum displacement path mentioned can advantageously be greater than 5 cm, particularly advantageously greater than 10 cm. This means that a very slight displacement of the cooking vessel, for example by 1 cm to 5 cm, which can also happen unintentionally, should not have any effect or the cooking vessel is then heated as before without intervention by a control of the hob. A shift direction can generally be neglected. This means that it can be taken into account that several cooking vessels can stand on the hob when in use and that it is not always possible to move them backwards, which is probably the most common and simplest case, but may also have to be done at an angle to the rear, possibly even afterwards front. In one embodiment of the invention, however, it could also be provided that the direction of displacement affects the amount and / or duration of the power reduction.

It is advantageously provided that the small surface power density and the large surface power density directly adjoin one another without a further power range for a surface power density in between, that is to say are only separated by a single fixed limit value. A very small surface power density or a very large surface power density can possibly be provided below or even above it.

A signal is particularly advantageously given to an operator by the hob when the displacement of the cooking vessel by at least the aforementioned minimum displacement has been determined. Such signaling can take place optically and / or acoustically. A signaling can take place in a similar form if, depending on the distinction in the first or the second case, the area power density has been maintained or has been reduced.

In one embodiment of the invention, it is possible that, when it has been determined that the cooking vessel is in the second position on the hob, that is, has been displaced by at least the mentioned minimum displacement, an operator is offered an option of the area power density determine, especially about the takeover or not. This option can be offered for a certain offer time, in particular 1 sec to 10 sec. During this offer time, an operator input, in particular on an aforementioned operator control device of the hob, can confirm or prevent a power takeover of the previous first surface power density or the setting of a new second surface power density. Thus, after moving the cooking vessel by more than the minimum displacement distance, an operator can receive a request, advantageously optically and / or acoustically, to accept or reject a future area power density shown by the hob on a display in the form of a cooking level as suggested by the hob. This can apply to the two aforementioned cases, i.e. both if the cooking vessel was first heated with the first small surface power density and should continue to be heated in the future, as well as if a reduction is to take place based on a first large surface power density.

It can be provided that in the second case of the previous operation with a high surface power density, the cooking vessel in the second position is first heated with the above-described reduced surface power density. In this way, account can be taken of the fact that in the above-described urgent case or, so to speak, an emergency, a power reduction takes place immediately, as an operator is used to with normal conventional hobs with individual heating devices. However, if the displacement of the cooking vessel is not based on such an undesired or dangerous state, but has taken place for other reasons, which above all also mean that the cooking vessel should continue to be heated with the large or even a very large surface power density, so can possibly with a single operating process or a one-time triggering of an operating element, for example by operating an operating element, the previous first high surface power density again during the offer time can be set. The assumption of the reduced performance would therefore be prevented. In this case, the interruption of the heating of the cooking vessel with the high surface area would be limited to a few seconds, and the effort or loss of comfort for an operator would also be acceptable.

If nothing is done by the operator during such an offer time, the area power density is determined and set in accordance with the previously described distinction in the first case or the second case.

A minimum displacement can not only be specified in centimeters or as an absolute dimension, but also in relation to the size or a diameter of the cooking vessel set up or one of the heating devices of the hob. A minimum displacement should be greater than 50%, advantageously greater than 65%, of a diameter of the cooking vessel or one of the heating devices.

In yet another embodiment of the invention, the minimum displacement path can be determined in that it is so large that at least one heating device previously covered by the cooking vessel in the first position sufficiently for heating operation, which was advantageously completely covered before, is in the second position of the Cooking vessel is no longer covered. With this definition for the minimum displacement path, this means that the operating state of at least one heating device has changed. Alternatively, it can also be provided that, in the second position, a heating device is covered by the hob, sufficient for a heating operation, advantageously completely, which was previously not or not sufficiently covered for a heating operation in the first position.

In a further embodiment of the invention it can be provided that the specific surface power density with which the cooking vessel is heated in the first position after it has been placed on the hob plate is specified by an operator. This can take place by a manual input on an operating device of the hob. Alternatively, an automatic cooking program or the like could also be used. determine this surface power density in the hob itself.

The detection of an overlapping of at least one heating device by the cooking vessel can either be carried out by the heating device itself, in particular if there are induction heating coils. These can determine their degree of coverage by a cooking vessel relatively reliably. The expert knows this. Alternatively, other sensors could also be provided be able to determine the overlaps or positions of cooking vessels on a hob.

A hob with which the above-described method can advantageously be carried out should have more than the usual four heating devices for four discrete hotplates. For example, three or two times four heating devices can be provided, in particular three times four heating devices. Their arrangement should be regular so that good coverage can be achieved. In particular, the heating devices should also be arranged relatively close to one another in order to be able to achieve the most complete possible heating of the cooking vessel at any position.

These and other features emerge from the claims and also from the description and the drawing, the individual features being implemented individually or in combination in the form of subcombinations in one embodiment of the invention and in other areas and being advantageous and protectable per se Can represent designs for which protection is claimed here. The subdivision of the application into individual sections and subheadings does not limit the general validity of the statements made under these.

Brief description of the drawing

Embodiments of the invention are shown schematically in the drawing and are explained in more detail below. The Fig. 1 a top view of an induction hob with a large number of induction heating coils and two possible displacement paths of a pot.

Detailed description of the exemplary embodiments

In the Fig. 1 A hob is shown in a plan view from above with a hob plate 12, under which a plurality of induction heating coils 15 are arranged in a heating area 13. Here three times four, that is to say twelve, heating devices are shown which essentially cover the area of the heating area 13. But there could also be more induction heating coils. The induction heating coils 15 are advantageously made the same size, particularly advantageously identical.

In the front area in front of the heating area 13 or adjacent to it, the hob 11 has a control device 17, advantageously by means of touch switches under the same hob plate 12. The control device has control elements 18, which can be formed, for example, by the mentioned touch switches, and at least one display 19. The display 19 is designed as a 7-segment display known per se. Here it shows a performance level "8".

A pot 21 is set up in the front area on the left on the hob plate 12 or the heating area 13 and covers two induction heating coils 15 in such a way that they jointly serve to heat this pot 21. The setting up of the pot 21 may have been recognized by the induction heating coils themselves. Alternatively, further sensors can have detected it or an operator can enter the information on the operating device 17 by means of the operating elements 18 that the pot 21 is to be heated at the front left. A power level is selected by means of further control elements 18, namely power level “8”, which is then shown in the display 19. This power level 8 corresponds to a surface power density of about 5 W / cm ² for the pot 21. It is therefore a large surface power density.

At any point in time, for example because water that is to be brought to the boil in the pot 21 is boiling strongly, the pot 21 is pushed backwards by the operator. This is intended to serve as a quick reaction to the fact that the water in the pot 21 threatens to boil over, which is not desired by the operator. Moving the pot 21 is then at least subjectively faster and more direct and more reliable for many operators than reducing the power by means of the operating device.

In the new second position 21 ', which is removed by the distance d from the original first position, this distance d being greater than a predetermined minimum displacement of, for example, 5 cm or 10 cm, the pot 21 with a reduced area power density can be used as a second new area power density operate. Thus, the power is reduced, namely at least to the limit value between small area power density and high area power density or a value between 3 W / cm ² and 4 W / cm ² , here 3.5 W / cm ² . If the distance d were less than the minimum displacement, no action would take place.

If the specified first surface power density were set to be less than 3.5 W / cm ² or less than 3 W / cm ² or a power level of "7" or "6" or below, no change and in particular no reduction in the surface power density or . of the performance level in the new second position.

If the case of the first surface power density is a high surface power density, the reduction of the power, otherwise the shifting and detection of the shifting of the pot, can be indicated optically and / or acoustically in a known manner.

According to the further possibility described at the beginning, after the pan has been fixed in the second position 21 or 21 'for up to 10 seconds from the hob 11 or from the operating device 17 and a control contained therein, the option of a power takeover after the move can be offered to confirm or prevent or undo. Especially in the case of a power reduction in the new second position, an operator can effect that the surface power density or the power level is not permanently reduced by actuating a special control element, which is for example optically displayed. However, since the area power density has been reduced at least temporarily immediately after the shift, it is then increased again to the original first area power density. If the operator lets more than the specified 10 seconds pass without valid actuation of the special operating element provided for this purpose, the reduced second area power density remains. This time of 10 seconds can generally also be varied and, for example, only be 3 seconds to 5 seconds or up to 20 seconds.

Claims (14)

1. Method for operating a cooktop (11) having multiple heating devices (15), wherein the cooktop has a cooktop plate (12) with a plurality of heating devices (15) arranged underneath, comprising the steps:

   - placing a cooking vessel (21) onto the cooktop plate (12) in a first position thereby covering at least one heating device (15),

   - operating the at least one heating device (15) with a certain predefined first area power density for heating the cooking vessel (21) and the contents therein, respectively,
   characterized in that by

   - displacing the cooking vessel (21) on the cooktop plate (12) by an operator at least along a certain minimum displacement path to a second position, wherein in a step with case discrimination as a function of the certain predefined first area power density for the at least one heating device (15) and by which the cooking vessel (21') is heated, a future area power density for the heating of the cooking vessel in the second position is determined,

   - wherein, in a first case of previous heating of the cooking vessel (21) with a small area power density, the cooking vessel (21') is further heated with the previous first area power density also on the second position,

   - wherein, in a second case of previous heating of the cooking vessel (21) with a great area power density, the future area power density by which the cooking vessel (21') is heated in the second position, is reduced.
2. Method according to claim 1, characterized in that the heating devices (15) are adjacent and/or cover the essential part of the surface underneath the cooktop plate in a regular pattern.
3. Method according to claim 1 or 2, characterized in that, in a second case of previous heating of the cooking vessel (21) with a great area power density, the future area power density is reduced at least to an area power density between 0.5 W/cm² and 4 W/cm² or to an area power density between a small and a great area power density.
4. Method according to claim 3, characterized in that the future area power density is reduced even more than to an area power density between 0.5 W/cm² and 4 W/cm² or to an area power density which is between a small and a great area power density.
5. Method according to any of the preceding claims, characterized in that the small area power density is less than 3.5 W/cm² and/or the great area power density is greater than 3.5 W/cm² or greater than 45% of the maximum area power density.
6. Method according to any of the preceding claims, characterized in that, after detection of the displacement of the cooking vessel (21'), an operator is given a signal, in particular using optical and/or acoustic signaling.
7. Method according to any of the preceding claims, characterized in that, after detection that the cooking vessel (21') is located in the second position on the cooktop (11), for a certain offering time, in particular 1 sec to 10 sec, the operator is offered an option to confirm or to prevent adoption of a power of the previous first area power density or of the new second area power density by an operating input.
8. Method according to claim 7, characterized in that, after expiration of said offering time, the area power density is determined according to the case discrimination in the first case or the second case.
9. Method according to any of the preceding claims, characterized in that the minimum displacement path is greater than 5 cm, preferably greater than 10 cm.
10. Method according to any of the preceding claims, characterized in that the minimum displacement path is greater than 50% of a diameter of the placed-on cooking vessel (21), preferably greater than 65%.
11. Method according to any of the preceding claims, characterized in that the minimum displacement path is long enough that at least one heating device (15) which in the first position is sufficiently covered for heating operation, preferably completely covered, is no longer covered by the cooking vessel (21') in the second position.
12. Method according to any of the preceding claims, characterized in that a minimum displacement path is long enough that a heating device (15) which in the first position is not sufficiently covered for heating operation, preferably not at all covered, is covered by the cooking vessel (21') in the second position far enough that it is operated in heating operation.
13. Method according to any of the preceding claims, characterized in that a certain area power density is predefined by an operator by an input on an operating device of the cooktop (11).
14. Method according to any of the preceding claims, characterized in that the cooktop (11) underneath the cooktop plate (12) includes at least two times four heating devices (15), in particular three times four heating devices.

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