EP1610590A1 - Cooking hob with a plurality of cooking zones - Google Patents

Abstract

The cooktop has heating units placed in a cooking plane. Detecting units (D1-D4) detect cooking containers placed at the right of a sub-assembly of heating units constituting a cooking zone. Predefined value of heater power is associated to the cooking zone according to adherence of the zone at portions of the cooking plane associated to the value.

Description

The present invention relates to a hob comprising several cooking zones.

It relates generally to the hobs comprising radiant or induction heating elements, suitable for heating a cooking vessel and its contents.

So we know cooktops for which outbreaks of cooking are predefined in the hob. Each home constitutes a cooking zone for heating a container.

Traditionally, for this type of hobs, the power can be set by the user according to the desired recipe, in a predetermined power range.

There are also known hobs in which several heating elements are arranged in the hob, means for detecting a container being adapted to detect the presence of a cooking vessel disposed above a set of heating elements. This set of heating elements thus constitutes a cooking zone for which the user can, as before, adjust a power of selected heater in a predetermined power range.

When the user wants to change the heating power associated with a container, it must adjust, at the level of a control panel, the heating power associated with the cooking zone on which is placed the container in question.

DE 40 07 680 also discloses a table of cooking in which a predefined heating power is assigned to a cooking zone.

However, only predefined cooking zones with a prefixed heating power are accessible to the user.

The present invention aims to facilitate the adjustment of the heating power associated with a container, and in particular to allow a intuitive adjustment by simple manipulation of the cooking vessel and modification its positioning on a cooking plan.

For this purpose, the present invention is directed to a hob comprising a plurality of cooking zones respectively associated with means for controlling a heating power of the cooking zone and means for detecting a cooking vessel at the right of these zones of cooking, the heating power associated with a cooking zone being equal to a predefined value and the control means are adapted to control in operation a cooking zone according to this heating power, when a cooking vessel is detected at the right of this cooking zone.

According to the invention, the hob comprises several elements heaters arranged in a hob, the detection means being adapted to detect a cooking vessel disposed at a subassembly heating elements constituting a cooking zone and the predefined value heating power is associated with the cooking zone as a function of the fact that this cooking zone belongs to a portion of the cooking surface associated with the predefined value.

Thus, the user no longer has to adjust the heating power associated with a cooking zone. From the positioning of a cooking vessel to the right of a cooking zone, the control means make it possible to heat this container to a predefined value of heating power.

In addition, the user has full latitude to position the container of baking at any point on the hob.

The hob is thus pre-cut fictitiously into several portions respectively associated with predefined power values of heated. Depending on whether the cooking zone belongs to one or the other of these portions of the hob, a valuable heating power predefined is associated with the cooking zone.

Preferably, the predefined value of the associated heating power to the cooking zone is calculated proportionally to the membership of the cooking zone to portions of the hob respectively associated with predefined heating power values.

By moving the container on the hob, especially in positioning the container on an area overlapping two plan portions associated with predefined values of heating power, it is possible to obtain a variation of the heating power delivered to the container, between the extreme values of heating power associated with the portions of the planes Cooking.

Preferably, the predefined values of heating power associated respectively to the portions of the hob are different each other.

Thus, the user can modify the heating power delivered to a container by moving it on the cooktop of a cooking zone to another.

It is thus possible to position the cooking vessel judiciously specific locations on the cooktop to allow for proper heating a predefined heating power.

This type of operation makes it possible to reconcile the use of modern cooktops of the traditional wood stove or coal, in which a cooking plate has a temperature which varies in depending on the distance from the combustion chamber. These traditional stoves allow the user to realize different cooking, requiring a strong heating power for grasping food, or otherwise low heating powers for simmering, judiciously positioning the container cooking at a specific place in the stove.

According to an advantageous characteristic of the invention, the values predefined heating powers associated with the portions of the hob are growing following a series of portions of the plan of cooking arranged from one edge to the other of the hob.

There is thus a succession of cooking zones arranged at proximity of each other and allowing, by a successive displacement of the container on the following cooking zones, to increase the heating power or on the contrary to decrease it according to the direction of movement of the container on the cooking plan.

Thus, according to the positioning of the cooking vessel between two edges of the hob, a predefined heating power will be associated with this container. This embodiment makes it possible to cover the range of heating power available between a minimum power and a maximum power, by simply moving the cooking vessel.

According to another characteristic of the invention, the hob comprises means for adjusting the predefined values of the powers of heaters associated with the portions of the hob.

The user can thus pre-set the predefined values of the heating power, depending on the subsequent use of the table of cooking.

The present invention is particularly advantageous when the cooking zones consist of one or more heating elements by induction.

Other features and advantages of the invention will appear still in the description below.

• la figure 1 est une vue de dessus d'une table de cuisson selon un premier mode de réalisation ;
• la figure 2 est une illustration schématique du système de commande de la table de cuisson illustrée à la figure 1 ;
• la figure 3 est une vue de dessus d'une table de cuisson conforme à un deuxième mode de réalisation ;
• la figure 4 est une vue schématique explicitant le fonctionnement de la table de cuisson illustrée à la figure 3 selon un mode de réalisation de l'invention ; et
• la figure 5 est un schéma illustrant un calcul de puissance intermédiaire, dans le mode de fonctionnement de la figure 4.

In the accompanying drawings, given as non-limiting examples:

• Figure 1 is a top view of a hob according to a first embodiment;
• Figure 2 is a schematic illustration of the cooktop control system shown in Figure 1;
• Figure 3 is a top view of a hob according to a second embodiment;
• Figure 4 is a schematic view explaining the operation of the cooktop illustrated in Figure 3 according to one embodiment of the invention; and
• FIG. 5 is a diagram illustrating an intermediate power calculation, in the operating mode of FIG. 4.

We will first describe with reference to Figure 1, a table of cooking according to a first embodiment.

FIG. 1 shows a schematic view from above of a Cooktop. Circles schematize the existence of cooking zones consisting here of independent cooking hobs on which a container of cooking can be laid.

Such a hob can be embedded or part integral part of a work plan. It can also be associated with other cooking devices, such as an oven arranged at the bottom.

Moreover, in addition to the cooking stoves that will be described below and their particular operation, the hob can include adjacent to other cookstoves of the same type or type different.

Here, by way of non-limiting examples, each cooking stove is consisting of one or more induction heaters. So, a Single disc-shaped inductor can materialize each cooking zone. Alternatively, each cooking zone may comprise several inductors concentric and, for example, three concentric inductors allowing to adapt the size of the cooking zone to the size of the container to be heated. This type of concentric inductor is well known and described in particular in the document FR 2 728 132.

By way of nonlimiting examples, FIG. 1 shows four cooking zones F ₁ , F ₂ , F ₃ and F ₄ , successively arranged at an edge 11 at an edge 12 of the hob 10.

The hob 10 has a front edge 13 corresponding to the front face of the hob 10 at which is positioned traditionally the user of the table.

Thus, the different cooking zones F ₁ to F ₄ are successively arranged from a left lateral edge 11 to a right lateral edge 12 of the hob.

Of course, the number of cooking zones, equal here to 4, is not limiting. In addition, the arrangement of the cooking zones could be different. Thus, a cooking zone could be arranged at the center of the table, different cooking zones being arranged around this cooking zone central, on the periphery of the hob.

A control panel 14 is generally provided near the front edge 13 of the hob to allow the user to control the operation and modify various parameters associated with the Cooktop.

This control panel 14 may comprise different keys sensitives whose functions will be described later.

FIG. 2 diagrammatically illustrates the operating control means of the cooking zones F ₁ , F ₂ , F ₃ and F ₄ .

In particular, each cooking zone F _i is associated with a control means C _i of the heating power of this cooking zone F _i .

Traditionally, these control means make it possible to operate each fireplace F _i independently, with a heating power determined by the user by means of a sensitive control provided at the control panel 14.

It is thus possible to adjust the power control of each home of individual way.

Detection means D _i are also associated with each cooking zone F _i so as to detect the presence or absence of a cooking vessel disposed in line with each cooking zone F _i .

These detection means are generally constituted by inductors, and here, by the inductors used to heat the container.

For example, the measurement of the effective current passing through each inductor is dependent on the surface of this inductor covered by a container.

The control of the value of the effective current thus makes it possible to determine the presence or absence of a container placed on the cooking zone concerned.

In a traditional hob, these detection means D ₁ , D ₂ , D ₃ and D ₄ make it possible in particular to automatically cut off the supply of the heating means associated with each cooking zone F ₁ , F ₂ , F ₃ and F ₄ when the container has been removed from the cooking zone.

In parallel with this traditional system of management of cooking hobs, the hob according to the invention comprises centralized control means C which make it possible to control the operation of the control means C _i as a function of the information given by each means of control. detection D _i .

In particular, thanks to these control means C, the control means C _i are adapted to control in operation each cooking zone F _i when a cooking vessel is detected in line with the cooking zone F _i .

The heating power then associated with each cooking zone F _i is equal to a preset value P _i memorized for each cooking zone F _i in the control means C.

Preferably, these predefined values of the heating powers P _i respectively associated with each cooking zone F _i are different from each other and cover the power range available on the hob.

As non-limiting examples, the heating powers P _i may be between 100 and 3000 W.

• P₁ = 3000 W pour F₁ ;
• P₂ = 1500 W pour F₂ ;
• P₃ = 500 W pour F₃ ; et
• P₄ = 100 W pour F₄.

With reference to FIG. 1, the predefined value of the heating power associated with each cooking zone may be equal to:

• P ₁ = 3000 W for F ₁ ;
• P ₂ = 1500 W for F ₂ ;
• P ₃ = 500 W for F ₃ ; and
• P ₄ = 100 W for F ₄ .

Thus, as illustrated in FIG. 1, the predefined values of the heating powers associated with each cooking zone are increasing following a sequence of cooking zones arranged between the two edges of the Cooktop.

In practice, it may be preferable to arrange the cooking zones F ₁ to F ₄ such that the predefined value of the heating powers associated with these cooking zones increases from a right lateral edge 12 to a left lateral edge 11 from the hob.

In the example described above, the preset values of the heating powers P _i are memorized by default in the control means C.

Optionally, the hob may include adjustment means accessible by the user to adjust these preset values of the heating power associated with each cooking zone F _i .

These adjustment means may consist of keys sensitives available at the control panel 14 of the table of cooking 10.

Thus, the user can customize the preset values of the heating powers P _i associated with each household F _i , the subsequent operation of the hob being automatically managed by the control means C so that as soon as a container is detected in relation to a cooking zone F _i , the associated power control means Ci control the operation of the cooking zone F _i to the heating power with a predetermined value P _i .

This hob thus allows the user to adjust the heating power associated with a container by simply moving this container on the hob and its arrangement opposite the different homes.

Thus, in the example illustrated in FIG. 1 and with the predefined values of the powers P _i given as an example above, the user can start a cooking process where it is necessary to grasp food, on the leftmost firebox. F ₁ controlled with a heating power equal to 3000 W. Then, the container can be moved on the fires F ₂ , F ₃ or F ₄ so as to choose a cooking zone, associated with a lower heating power, to make simmer the contents of the container.

In practice, when the user wishes to start a cooking, he places a container on the firebox F _i corresponding to the type of cooking he wishes to perform, then activates a cooking command, for example by pressing a touch sensitive available at from the control panel 14.

The activation of this cooking control key has the effect of controlling the operation of the central control means C. The information given to the control means C by the detection means D ₁ , D ₂ , D ₃ and D ₄ allows to determine the focus F ₁ , F ₂ , F ₃ and F ₄ on which the cooking vessel is placed. In response, the power control means C ₁ , C ₂ , C ₃ and C ₄ associated with the focus thus identified are implemented to deliver the heating power to the preset value for this focus.

Then, the central control means C continuously monitor the presence of the container on the hearth, so that when the container is moved from one focus to another, the central control system C receives the displacement information of the container. . In this case, the central control system again identifies from the detection means D _i the hearth on which the container was placed. Once the hearth thus detected, the control means associated with this new focus are implemented to control in operation this cooking stove according to the preset value heating power stored in the central control means C.

Note that when using more than one container on the table of cooking, the user must activate the cooking control at the table 14 for each new container added to the table.

The arrangement of the cooking heaters F _i could be different, and for example the higher-powered fireplace F ₁ could be located substantially in the center of the hob, the lower power fires F ₂ , F ₃ and F ₄ being arranged around of this central hearth F ₁ , at the periphery of the hob 10.

We will now describe with reference to FIG. cooking according to a second embodiment.

The hob is thus schematically represented from above.

As before, this hob can be built-in or be an integral part of a work plan and possibly be associated with other cooking devices, such as an oven or other cooking stoves arranged in the same plane.

In this embodiment, the hob has a multitude of heating elements, and for example several elements induction heaters of small dimensions arranged in a matrix cooking plan.

The heating elements 21 are thus distributed in a frame two-dimensional in the hob of the table 20.

This hob thus has a large cooking zone dimension, which can reach the dimension of the hob and heat one or more containers without predetermined location of the cooking stove.

Each heating element 21 consists of a small winding or elementary inductor. Preferably, these heating elements 21 are of circular shape and staggered in the hob, so to cover the entire surface of the hob.

The size of the inductors 21 is small enough that any container size covers at least one elementary inductor.

For example, the diameter of each elementary inductor 21 can be equal to 70 or 80 mm.

Each inductor is powered independently and has independent heating power control means. As for example, the maximum power supplied by each inductor is of the order of 700 W. It is thus possible to obtain a total power of 2800 W approximately for a medium-sized container, approximately 18 cm in diameter, which recover four inductors 21.

The traditional control system of such a hob allows to manage one or more containers placed on the hob and to apply different powers, depending on the nominal power requested by the user, for each container.

For this purpose the hob 20 has a control keyboard and visualization 22. Each heating element 21 is associated with a means of detection of the presence of a container placed on the hob to the right of this heating element 21.

In the particular example described here, the elementary inductors 21 constitute both the means of heating the container and the means of detecting the presence of a container.

As before, the measurement of the effective current passing through each inductor is dependent on the surface of this inductor covered by a container.

The control of this effective current thus makes it possible to determine the covering of this inductor by a container placed on the hob.

By measuring the effective current, the position of the container on the plane can be determined and a cooking zone consisting of one or several adjacent inductors can thus be defined.

Various improved detection methods are described particularly in the French patent application No. 0313925 in the name of the Applicant.

In this embodiment of the invention, the hob 20 as before, there are centralized control control the operation of the control means by power of each inductor so that the heating power associated with a detected cooking zone is equal to a predefined value.

In practice, the predefined value of the associated heating power each cooking zone may depend for example on the relative position of this cooking zone with respect to two edges of the hob.

As a non-limitative example, the value of heating power predefined can depend on the position of the container in relation to the distance separating left side edges 23 and 24 right of the hob.

In practice, when a container is placed on the hob 20, the user indicates by means of a control key provided at the level of the control panel 22 adding a container to the cooktop 20.

The centralized control means are then adapted to analyze the answers provided by the means of detecting the presence of a container.

In practice, the value of the measured effective current at the level of each of the inductors 21 allows the centralized control means to determine the inductor (s) covered at least partially by a container. This set of elementary inductors 21 thus constitutes a zone Cooking.

In practice, it will be noted that an elementary inductor 21 belongs to a cooking zone when its recovery rate is greater than one threshold value, for example 10%.

The centralized control means are further adapted to determine the heating power to be associated with this cooking zone Z.

For example, when the detected cooking zone Z is adjacent to the left side edge 23 of the hob, the power of associated heating corresponds to a maximum heating power. So, for a medium-sized container covering about four inductors, the value predefined heating power will be in the range of 2800-3000 W.

In contrast, when the detected cooking zone Z is adjacent to the right lateral edge 24 of the hob 20, the predefined value of the heating power associated with this cooking zone Z may be equal to the minimum value of the hob, of the order of 100 W.

Any intermediate position of the detected heating zone Z gives to a calculation of a predefined value of heating power dependent on the relative position of the container with respect to these two lateral edges 23, 24.

For example, when the detected cooking zone Z is disposed at mid-distance from these edges 23, 24, the predefined value of the heating power associated with this cooking zone Z is equal to 50% of the maximum value of the power delivered by the covered inductors.

Of course, the relative position of the cooking zone could also be determined with respect to the center and one edge of the table of cooking.

Thus, in such an embodiment, when the cooking zone detected Z is located in the center of the hob, the heating power has a predefined maximum value. Moving the container away from the center of the table cooking, towards the edges, the new cooking zones detected Z are associated with a heating power with a lower preset value.

Thus, when using this hob, the user can modify the heating power delivered to the container by simple displacement of the container on the hob.

As soon as the cooking vessel is moved, the control means centralized sensors detect, by means of the value of the measured rms current level of each elementary inductor 21, the displacement of this container and the new cooking zone Z moved.

Depending on the positioning of this cooking zone Z, the heating power is changed to equal the preset value, stored or calculated by the centralized control means.

In practice, when a heating power of a predefined value P is associated with a cooking zone Z consisting of several inductors, the power is distributed over each of these inductors according to their rate of recovery.

This distribution makes it possible to minimize the field radiated by the inductors partially covered when the current flowing through these inducers little covered is reduced.

   où P est égal à la valeur prédéfinie de la puissance de chauffe associée à cette zone de cuisson Z, T_j est égal au taux de recouvrement de chaque inducteur I_j et n est égal au nombre d'inducteurs élémentaires I_j appartenant à la zone de cuisson Z.Thus, by way of example, the basic power delivered by each inductor P _j I _j belonging to a heating zone Z is of the type:

where P is equal to the predefined value of the heating power associated with this cooking zone Z, T _j is equal to the recovery rate of each inductor I _j and n is equal to the number of elementary inductors I _j belonging to the zone cooking Z.

A second mode of operation of the hob 20 such illustrated in Figure 3 will now be described with reference to Figure 4.

In this second mode of operation of the hob 20, the hob is partitioned into several portions, each portion of the hob being associated with a predefined power value of heated.

When a container is placed on the cooktop and an area is Z cooking is thus detected, the heating power associated with this zone is equal to the preset value of heating power associated with the portion of the hob.

In practice, in the exemplary embodiment illustrated in FIG. baking plan is cut into three portions 25, 26, 27.

Of course, the number of three portions is only given to as an example and may be less than or greater than 3.

Each portion 25, 26, 27 is associated with a predefined value of heating power P ₁₂ , P ₁₀ and P ₆ , respectively equal for example to 3000, 1500 and 500 W, for a medium-sized container covering approximately four elementary inductors 21 .

The preset heating power values P ₁₂ , P ₁₀ and P ₆ are stored by default in the centralized control means.

In this embodiment, the portions of the hob are substantially rectangular and arranged successively from one edge to the other of the hob.

Of course, the portions of the hob could be arranged from the center to the edges of the hob, the power of associated with the central portion in the form of a circle being greater than the outer portion adjacent to the edges of the cooktop.

In this embodiment, the hob would thus be shared for example in a disk-shaped central zone, an intermediate zone annular, and an outer zone extending between the annular intermediate zone and the edges of the hob.

Moreover, the hob 20 could also include adjusting means at the control panel 22, accessible to the user and allowing him to pre-set the predefined value of the heating power associated with each portion 25, 26, 27 of the hob.

Although we have schematized in Figure 4 separations of the plane of by fictitious rectilinear lines X, it may be better to hold account of the arrangement of elementary inductors 21 arranged a matrix.

As illustrated in Figure 5, in practice, each portion 25, 26, 27 corresponds to a certain number of inductors, each inductor elementary 21 wholly belonging to one or other of these portions 25, 26.27.

When a container such as the container referenced R ₁ in Figure 4 is placed on the cooking plane, and the associated cooking zone belongs to a portion 25 of the hob, the control means in operation of the elementary inductors covered 21 are implemented to control in operation this cooking zone according to the heating power of predefined value P ₁₂ .

As before, the predefined heating power P ₁₂ is distributed over the different elementary inductors 21 belonging to the cooking zone, as a function of the recovery rate of each inductor by the receptacle.

The user can modify the heating power delivered to the container R ₁ by moving it on the hob, and in this example, it can reduce the heating power from a maximum value to a minimum value by moving the container from the left to the right of the hob 20.

When the container is placed on the hob astride two portions of the hob, as is the case for the container referenced R ₂ in Figures 4 and 5, which is placed on both the portions 26 and 27 of the hob, the predefined value of the heating power P associated with the cooking zone thus detected is calculated proportionally to the membership of this cooking zone to the portions 26, 27 of the hob.

Thus, an intermediate heating power associated with the container R ₂ corresponds to an average of the predefined values of the heating powers associated with each portion 26, 27 partially covered by the container.

The average of the powers can thus be weighted according to the recovery rate of each elementary inductor 21 belonging to the cooking zone detected.

As illustrated in FIG. 5, when the receptacle R ₂ is disposed both on the portions 26 and 27 of the hob, the average takes into account the number of inductors covered by the receptacle R ₂ and the recovery rate of each of these inductors 21.

• T₁ = 100% ;
• T₂ = 100% ;
• T₃ = 100% ; et
• T₄ = 40%.

Thus, in this example, the container R ₂ covers four elementary inductors 21 whose recovery rates are as follows:

• T ₁ = 100%;
• T ₂ = 100%;
• T ₃ = 100%; and
• T ₄ = 40%.

The predefined value of the intermediate heating power P associated with the cooking zone covered by the container R ₂ will be calculated, for example, as follows: P = (T 1 T + 2 T + 4 ) P 10 + T 3 P 6 T 1 T + 2 T + 3 T + 4

Other methods of proportional calculation of the power could also be implemented, for example taking into account the surface portion of the container belonging to each portion 26, 27 of the table Cooking.

Thus, the user can, by moving the container on the hob, change the heating power associated with this container between the P ₁₂ to P ₆ values of available power.

Of course, many changes can be made to the embodiments described above without departing from the scope of the invention.

In particular, the heating element (s) of the hob constituting each cooking zone could also be elements radiant heaters, electric heating elements or gas burners, as soon as when a device for detecting the presence of a container can be set parallel to the hob, for example by means of a Matrix matrix of inductors for detecting the presence of a load placed on the cooking surface.

Claims (7)

Cooking hob comprising a plurality of cooking zones (F _i ) associated respectively with control means (C _i ) of a heating power of said cooking zone and detection means (D _i ) of a cooking vessel with right of said cooking zones, said heating power (P _i ) associated with a cooking zone (F _i ) being equal to a predefined value and said control means (C _i ) being adapted to control in operation a cooking zone ( F _i ) according to said heating power (P _i ) when a cooking vessel is detected in line with said cooking zone (F _i ), characterized in that it comprises a plurality of heating elements (21) arranged in a cooking plane cooking, said detection means being adapted to detect a cooking vessel (R ₁ , R ₂ ) arranged in line with a subset of heating elements (21) constituting a cooking zone (Z), and in that said predefined value of the power of ch auffe (P) is associated with said cooking zone (Z) as a function of the belonging of said cooking zone (Z) to a portion of the cooking plane (25, 26, 27) associated with said predefined value (P ₁₂ , P ₁₀ , P ₆ ). Cooktop according to claim 1, characterized in that said predefined value of the heating power (P) associated with said cooking zone (Z) is calculated proportionally to the membership of the cooking zone (Z) at portions of the hob (26, 27) respectively associated with predefined values of the heating powers (P ₁₀ , P ₆ ). Cooktop according to one of claims 1 or 2, characterized in that said predefined values of the heating powers (P _i ) respectively associated with the portions of the cooking surface (25, 26, 27) are different from each other . Cooktop according to claim 3, characterized in that said predefined values of the heating powers (P _i ) respectively associated with the portions of the cooking surface (25, 26, 27) are increasing in a succession of portions of the cooking surface. disposed from one edge (11, 23) to the other (12, 24) of said hob (10, 20). Cooktop according to claim 3, characterized in that said predefined values of the heating powers (P _i ) respectively associated with the portions of the cooking surface (25, 26, 27) are decreasing according to a series of portions of the cooking surface. disposed from the center of the hob (10, 20) to an edge of said hob (10, 20). Cooktop according to one of claims 1 to 5, characterized in that it comprises means (14, 22) for adjusting said predefined values of the heating powers (P _i ) associated with the portions of the hob (25). , 26, 27). Cooktop according to one of claims 1 to 6, characterized in that said cooking zones (Z) consist of one or more induction heating elements (21).

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