WO2008058614A1

WO2008058614A1 - Inductive cooking zone, induction hob and drive method

Info

Publication number: WO2008058614A1
Application number: PCT/EP2007/009244
Authority: WO
Inventors: Sören Kaizik
Original assignee: E.G.O. Elektro-Gerätebau GmbH
Priority date: 2006-11-15
Filing date: 2007-10-25
Publication date: 2008-05-22
Also published as: DE102006054973A1

Abstract

An induction hob (11) comprises two elongate cooking zones (15a, 15b), which each comprise six strip-shaped inductors (17a, 17b) and themselves are in the form of strips. The inductors (17) can be combined functionally depending on the coverage by a cooking vessel (19) placed thereon for common operation as a cooking point (16). All of the inductors (17) are advantageously of identical design.

Description

Description Inductive cooking zone. Induction hob and control method

Field of application and state of the art

The invention relates to an inductive cooking zone according to the preamble of claim 1 and an induction hob with at least two such cooking zones and a method for the respective control.

Cooktops with inductive heating and inductive cooking zones are known from the prior art and have known advantages such as short heating times, high power transmission and lower risk when removing the cookware from the cooking area, since then the power generation or transmission automatically stops.

Furthermore, it is known from EP 862 714 A1 to form an induction hob of many individual cells or single inductors. As a result, a cooking vessel can be placed anywhere on the hob and is then heated with its size corresponding number of cells. Here, however, a considerable effort for construction, connection and control of the many individual cells is necessary.

Task and solution

The invention has for its object to provide an aforementioned cooking zone, an induction induction hob mentioned above and methods for each control, with which problems of the prior art can be avoided and with limited effort a certain variability or freedom of movement during inductive cooking is possible. This object is achieved by an inductive cooking zone with the features of claim 1, an induction hob with two such cooking zones with the features of claim 2 and a method for driving with the features of claim 8. Advantageous and preferred embodiment of the invention are set forth in the other claims and are explained in more detail below. Some features are listed only once, but they should apply regardless of both a cooking zone, the induction hob or a control method. The wording of the claims is incorporated herein by express reference.

It is envisaged that an inductive cooking zone in the form of an elongated strip, in particular a straight strip, which in special designs, curved or curved strips are conceivable. The length of the cooking zone is greater than its width, in particular by a multiple. The cooking zone has a plurality of inductors, which are arranged along one direction, namely the longitudinal direction of the cooking zone, side by side and adjoin each other, in particular with a very small distance or directly abutting one another. It is advantageously possible for such an arrangement of the inductors to be provided close to or directly next to one another exclusively along one or the longitudinal direction of the cooking zone. As will be explained in more detail below, in an induction hob according to the invention, two or even more such cooking zones can run side by side or parallel to one another. Advantageously, however, the distance between the inductors of different cooking zones then amounts to a few centimeters, which is then no longer to be regarded as "next to one another." In particular, the distance between inductors of two different cooking zones is just greater than the distance between them Inductors within a cooking zone The inductors are shorter in the longitudinal direction of the cooking zone than in the Direction of the cooking zone, that is elongated. According to the invention, at least four inductors are provided side by side, wherein an inductor is at least half longer than wide.

Thus, it is possible with the invention to build an inductive cooking zone of, for example, five to ten or advantageously six to eight elongated inductors side by side, which then form or allow in particular two cooking zones. At the same time, there is no need to provide an excessively large number of inductors, unlike, for example, the 40 or even more individual inductors according to EP 862 714 A1 mentioned in the introduction. Thus, the invention is well suited, for example, for applications in which a certain freedom of placement of the cooking vessel on a hob and thus a variable operation is possible, but no complete freedom of movement is necessary.

In an embodiment of the invention may be provided to simplify the manufacture and assembly that several of the inductors are the same size and the same design. In particular, all inductors of the cooking zone are identical or identical.

Advantageously, five to ten inductors are provided per cooking zone. This makes it possible, for example, to provide three inductors per imaginary cooking point, if an operation with as many cooking pots on the cooking zone should be possible. Particularly advantageous six to eight inductors are provided. This is a good average between variability and location of the cooking hob formed for an attached cooking vessel and effort.

It can be provided, even if several cooking zones are integrated in an induction hob, that no common power electronics is provided for several cooking zones, but at least its own power electronics for each cooking zone. This can be several or even all inductors of this cooking zone are supplied. Such a power electronics for supplying a plurality of inductors operates advantageously according to the phase-shift principle for the variable control of one, two, three or more inductors. At the same time, it is preferably provided that several or advantageously all inductors can be controlled independently of one another. Thus, an optimal adaptation to the defined by placing a cooking vessel and required operation of the cooking zone in the form of a cooking point thus formed is possible.

In one embodiment of the invention, the inductors are advantageously designed, arranged and controlled in such a way that adjacent inductors or adjacent inductors always flow in opposite directions from the current. Thus, uniform magnetic field lines can form or the magnetic field lines of adjacent inductors act together for optimum power transmission.

In concrete embodiment, an inductor can either have an elongated rectangular shape or an elongated ellipse shape, which is approximated to a rectangular shape. So it can be tried to reach from the coil wire of the inductor at the ends or corners to approach to such a rectangular shape, without having to bend the coil wire. Furthermore, it is possible that an inductor is significantly longer than wide, for example two to three times as long. This may depend, above all, on the desired length of the cooking zone, the desired number of inductors therein and general considerations for the design of the cooking zone.

The cooking zone itself can be two to four times as long as it is wide. In particular, it is two to three times as long, so that two or three hotplates can be formed therein, which in turn are approximately quadratic. Table are for round cooking vessels or rectangular for oblong roasting tins or the like.

Advantageously, several inductors can be combined in a cooking zone to form power modules. In this case, for example, two or three inductors form such a power module. One of the advantages of a power module is that it has its own power electronics, for example according to the aforementioned phase-shift principle. This power electronics is independent of the other power modules or their power electronics, but can cooperate in a favorable manner with these, for example, for a joint operation of two adjacent inductors each having a power module.

In a further advantageous embodiment of the invention, a power module can also be characterized in that it forms a ready-to-install unit. So, so to speak, with one operation, a power module, which in turn has two or three inductors, be installed in a hob instead of the inductors individually. If these power modules then also have their own power electronics, which is advantageously structurally integrated in the unit, so a modular design for a cooking zone can be achieved, which is simple and reasonably fail-safe. For further simplification, a cooking zone or, under certain circumstances, an induction hob has only identical power modules. This reduces the number of necessary variants and thus the effort while maintaining variability in operation.

An induction hob according to the invention may advantageously have two or, under certain circumstances, even more cooking zones of the aforementioned type. These run with some distance to each other in the range of a few centimeters and with their long sides parallel to each other. It is Although, as mentioned above, possible to arrange them arcuate, but they are advantageous straight. The two cooking zones are constructed according to a basically same design principle and advantageous in the aforementioned manner. However, this does not preclude the provision of yet another and possibly different cooking zones in the hob, but means that at least two similar aforementioned cooking zones are present. These cooking zones are advantageously the same length. They may be of different widths to accommodate both smaller and larger cooking vessels. For example, a rear cooking zone may be wider than a front cooking zone.

From the geometry, it can be provided that the ratio of width to length of the individual inductors is similar to that of a cooking zone. This is especially true in a cooking zone with a slightly smaller width than the other.

The small distance between the inductors of two different cooking zones should also functionally mean that inductors of these two different cooking zones are not actually intended for common operation, so a cooking vessel should not be so set up and heated that it overlaps this dividing line. This can also be clarified, for example, by corresponding markings on the upper side of the hob, in particular on a corresponding glass-ceramic plate.

From the driving method forth can be provided in an embodiment of the invention that a cooking zone is divided into two functional areas or halves, these areas are then approximately end. An operator can enter for a cooking zone a desired use of a part of the cooking zone as a cooking place for a cooking vessel in one or the other end area or the half, in particular special about operating means such as usual operating means. Thereafter, the cooking vessel is placed on this area or this half to form a hotplate for this cooking vessel. The cooking zone then recognizes, similar to a conventional induction hob, the performance parameters of the inductors, which inductors are largely covered by the cooking vessel. These inductors are then operated with a power level selected by the operator via control means. Thus, in this method, therefore, an area is approximately specified in which a cooking vessel is placed and then to be heated. In this area, the hob then automatically checks which inductors are covered to a sufficient extent that they are operated to heat the cooking vessel. As a measure of an overlap, for example, 2/3 or 3/4 of the area of the inductor can be taken, which can be detected in a known manner via the control.

The choice of power level can advantageously be done after the cooking vessel has been set up on the cooking zone, and particularly advantageously after the inductors to be operated have been detected. For this purpose, after completion of this detection, the cooking zone or the hob of an operator give a corresponding signal, connected with the request to choose now the power level. Alternatively, it is of course possible to choose the power level before setting up the cooking vessel on the cooking zone.

In both cases mentioned above, however, it is also possible to change the power level at any time after recognition of the inductors to be operated and thus after determining the hotplate via the aforementioned operating means. Such operating means may be common operating means for a hob, such as touch switches. If two pairs of touch switches are provided per cooking zone, each with a plus button and a minus button to increase the power and power reduction can be created per cooking zone two hotplates of variable size. In this way, the hob can already recognize on the basis of the operation of one of the pairs of touch switches for power adjustment, which should include the areas or halves of the cooking zone operation as a hotplate, and put them as above, so to speak, ready to recognize then patch cooking vessels and then determine the number of inductors to be operated. Alternatively, selection switches may be provided for individual areas or cooking hobs to be formed and only one pair of touch switches or other power adjustment operating means.

These and other features will become apparent from the claims but also from the description and drawings, wherein the individual features each alone or more in the form of sub-combinations in an embodiment of the invention and in other fields be realized and advantageous and protectable Represent embodiments for which protection is claimed here. The subdivision of the application into individual sections and subheadings does not restrict the general validity of the statements made thereunder.

Brief description of the drawings

Embodiments of the invention are shown schematically in the drawings and are explained in more detail below. In the drawings show:

1 is a plan view of a first inventive induction hob with two cooking zones according to the invention and erected cooking vessels,

2 is an illustration of a single inductor, Fig. 3 shows the merger of four inductors of FIG. 2 to a power module with marked field line and

Fig. 4 shows another inventive, alternative induction hob with different widths cooking zones.

Detailed description of the embodiments

In Fig. 1, an inventive induction hob 11 is shown with a cooktop plate 12, for example made of glass ceramic. Bottom left are arranged along the leading edge controls 14, for example in the form of touch switches. Each control element identified by a round marking has function assignments represented by plus or minus symbols.

The induction hob 11 has a rear, transverse cooking zone 15a and a front, parallel cooking zone 15b. The cooking zones 15a and 15b each consist of six inductors 17a and 17b. These are identical and will be explained in more detail in FIGS. 2 and 3 later. As can already be seen from FIG. 1, the inductors 17 of a cooking zone 15 are arranged very close to one another or can almost touch each other as components. However, the two cooking zones 15a and 15b have a distance of a few centimeters to each other.

On the induction hob 11 there is a large cooking vessel 19 on the right-hand side. It completely covers an inductor 17a and largely encloses the inductors 17a adjacent to the right and left. This has detected the induction hob 11 and therefore operates these three inductors 17a together as a hotplate 16a2. This hotplate 16a2 is illustrated by the dark hatching of the three inductors 17a. Because of the course of the magnetic field lines in the bottom of the erected cooking vessel 19, it does not matter that the respective remote corners the lateral inductors 17a are not covered by the cooking vessel 19. The resulting magnetic field lines run through the bottom of the cooking vessel.

Similarly, a small cooking vessel 19 ^{'is placed} on the front left of the front cooking zone 15b. Thus, in turn, the two inductors 17b covered thereby form a front left cooking point 16b. In the right-hand area of the front cooking zone 15b, a medium-sized cooking vessel 19 ^"is set up, largely covering two inductors 17b, which then together form a hotplate 16b2.

As can be seen by the marking and arrangement of the controls 14, the induction hob 11 is provided for operation with two front cooker and two rear burners 16. From the arrangement of the controls 14 can also be seen that these hotplates 16 at each cooking zone either should lie in the left or in the right half, wherein they can each cover one, two or three inductors 17.

In Fig. 2, a single inductor 17 is shown. It is wound from coil wire 18 approximately in a rectangular shape and has two terminals 21 for power supply. As generally known by inductors, the inductor 17 is also advantageously applied to a support for securing the turns and for mechanical fastening.

In Fig. 3 it is shown how four inductors 17 are summarized according to the embodiment of FIG. 2 to form a power module 22. For this purpose, they are arranged on a continuous support, not shown, or firmly connected to each other, so that they form a structural unit. They form matching and complementary or reinforcing magnetic field lines. For the rightmost inductor 17, the terminals 21 are shown, which are connected schematically to a power electronics 23 of the power module 22. The power electronics 23 can be controlled or influenced by means of a control 24 on the basis of the commands entered by the operating elements 14 of an operator. Furthermore, the power electronics 23 are also connected to each of the other inductors 17 via separate terminals, not shown, so that these four inductors 17 of the power module 22 can be controlled via the own power electronics 23. It is thus determined by the controller 24 together with the inductors 17 in a known per se, which of the inductors are covered by a cooking vessel 19 in a sufficient degree, so that they are activated. Within a power module 22 only adjacent inductors 17 are operated together or a contiguous area, namely then form the cooking zone 16. Embodiments of induction hobs with other controls or for a more variable operation may well provide that any adjacent power modules of a cooking zone recognize that they are covered together by a cooking vessel, so that then each covered inductors are operated together as a single hob.

4, an alternative embodiment of an induction hob 11 1 is shown again with two cooking zones 115a and 115b. These each consist of four inductors 117a and 117b. However, the inductors 17b of the front cooking zone 115b are shorter than the rear ones, so that this cooking zone is narrower than the other. Both cooking zones are each constructed of eight inductors 117, and in principle of two power modules according to FIG. 3. Due to the shorter inductors 117b of the front cooking zone 115b, this is predestined for smaller cooking vessels. Depending on the type of control via control elements 114, which are shown here only schematically, it is possible that three cooking zones are formed for three cooking vessels, wherein a cooking vessel set up approximately in the central area can also cover an inductor of the left and an inductor of the right power module and these are then operated together as a cooking place.

Claims

claims

An inductive cooking zone (15, 115) in the form of an elongate strip whose length is greater than its width, said inductive cooking zone having a plurality of inductors (17, 117) arranged side by side along one direction and arranged in the longitudinal direction of the Cooking zone (15, 115) are shorter than in the width direction of the cooking zone, characterized in that at least four inductors (17, 117) are provided and an inductor is at least half longer than wide.

2. induction hob with two cooking zones (15, 1 15) according to claim 1, characterized in that the two cooking zones (15, 115) with some distance from each other and with their longitudinal sides parallel to each other, both cooking zones (15, 115) after a basically the same design principle are built.

3. Induction hob according to claim 2, characterized in that the cooking zones (15, 115) are the same length, wherein they are in particular of different widths.

4. induction hob according to claim 2 or 3, characterized in that at a cooking zone (15, 115) the width of the individual inductors (17, 117) in relation to their length is similar to the cooking zone, in particular in a cooking zone (15, 115) with a smaller width.

5. induction hob according to one of claims 2 to 4, characterized in that all inductors (17, 117) of the induction hob (11, 111) are identical and the cooking zones (15, 115) identical power modules (22), wherein the inductors ( 17, 117) of a cooking zone (15, 115) in power modules (22), wherein preferably one power module comprises two or three inductors (17, 117) and in particular each power module (22) has its own power electronics

(23),

6. Induction hob according to claim 5, characterized in that a power module (22) forms a ready-to-install unit and preferably the cooking zone (15, 115) has identical power modules (22).

7. Induction hob according to one of claims 2 to 6, characterized in that the inductors (17, 117) of two cooking zones (15, 115) have a small distance from each other, preferably a few cm.

8. A method for controlling an inductive cooking zone (15, 115) according to claim 1 or an induction hob (11, 111) according to one of claims 2 to 7, characterized in that a cooking zone (15, 115) functionally in at least two end regions or Divided halves and an operator for a cooking zone (15, 115) enters a desired use of a sub-zone of the cooking zone in one or the other end portion or half of the cooking zone via operating means (14, 114) and then a cooking vessel (19) this end portion or this half sets up, wherein the cooking zone (15, 115) detects which inductors (17, 117) are largely covered by the cooking vessel (19) and these inductors (17, 117) then with a selected power level by the operator operate.

9. The method according to claim 8, characterized in that the coverage of the inductors (17, 117) is at least 60% to 70% for operating an inductor (17, 117).

10. The method according to claim 8 or 9, characterized in that the choice of power level after setting up the cooking vessel (19) on the cooking zone (15, 115) takes place and after detecting the inductors to be operated (17, 117), preferably a Signal from the cooking zone (15, 115).

11. The method according to claim 8 or 9, characterized in that the choice of the power level before setting up the cooking vessel (19) on the cooking zone (15, 115).

12. The method according to any one of claims 8 to 11, characterized in that a change in the power level after detecting the inductors to be operated (17, 117) for precisely these inductors at any time via operating means (14, 114), in particular via the same operating means as already before to select the power level.

13. The method according to any one of claims 8 to 12, characterized in that the operating means are common operating means for hobs, preferably touch switch (14, 114), wherein in particular per cooking zone (15) two pairs of touch switches (14) are provided with a plus - And a minus button to increase performance and performance reduction, the operation of the plus or minus button is also the input of the end portion or half of the cooking zone (15, 115) by the operator at the same time.