EP1686836A1 - Carrier for an induction coil, an induction heating device, an induction cooktop and a procedure for manufacturing an induction heating device - Google Patents

Abstract

The carrier has upper and lower plates (14, 15) acting as supporting devices, which are mechanically connected with each other such that a narrow gap is formed between the devices. An induction coil (11) made from a single continuous winding wire including windings is inserted in the narrow gap such that the coil is clamped through the spacing of the supporting devices. The spacing lies within the range of the coil dimension. Independent claims are also included for the following: (A) an induction hob including an induction heating device with an induction coil (B) a method for manufacturing an induction coil.

Description

Field of application and state of the art

The invention relates to a support for an induction coil, in particular in a flat design, as well as an induction heater and a method for producing such an induction heater and an induction cooktop.

It is known, for example, from EP 713 351 A1 to coil the coil wire onto a carrier with prefabricated grooves or groove-like depressions in a single layer for an induction heating device of an induction hob. It is fixed by gluing, for example.

Task and solution

The invention is based on the object, an aforementioned carrier, an induction heater and a method for producing an induction heater to create, with which problems of the prior art can be solved and in particular an induction coil of precisely defined shape and design can be made as simple as possible.

This object is achieved by a support with the features of claim 1, an induction heater with the features of claim 13, an induction hob the features of claim 15 and a method of manufacturing an induction heater with the features of claim 16. Advantageous and preferred embodiments of the invention are the subject of further claims and are explained in more detail below. The wording of the claims is incorporated herein by express reference. Features describing both the carrier and the induction heater, as well as their method of manufacture, are given in part only in the following. Nevertheless, they apply in each case independently of each other for carrier and induction heating device or their production process.

The carrier has an upper support means and a lower support means forming a narrow gap. They may, for example, be substantially plate-like or flat. In this narrow space, which may also have the shape of a very deep groove, the induction coil is introduced or built therein. In this case, the induction coil is advantageously constructed from a continuous coil wire, which is particularly advantageous a relatively thick multiple strand. An insulation of the coil wire to the outside or the individual strands is advantageously carried out by a paint-like coating instead of a coating-like plastic sheath. Particularly advantageously, the coil wire is wrapped in the gap, that the resulting induction coil is single-layered.

Thus, it is advantageous in a single-layer induction coil possible, in particular if the distance between the two support means from each other or the gap is in the range of the thickness of the coil wire, that the coil wire is under slight clamping effect in the intermediate space. In this way, a positional fixation of the coil wire or the individual turns is possible for a stable and durable construction of the induction coil or an induction heater to the desired extent. Further bonds or fixations can be omitted.

Furthermore, it is possible to produce the carrier as a structural unit or essentially or entirely entirely from a single part. In this case, the support means may be connected to a connecting piece, which is formed in particular in the central region. Elaborate assembly steps before or after the winding or insertion of the coil wire are therefore not necessary. It can be made of plastic. Alternatively, at least the lower support means may comprise ferromagnetic material, for example in strip form with radial direction or consist thereof, in particular also the upper support means. Thus, the magnetic field can be redirected and so the total inductance of the induction coil can be changed.

The support means advantageously form support surfaces which define the space and thus the space in which the induction coil or the coil wire is introduced. For the formation of the support means or the support surfaces formed by this, there are basically several options. On the one hand, it is possible to form them over the entire surface or as closed support surfaces. As a result, for example, a very stable carrier can be created. On the other hand, at least one of the support means or the support surfaces may have recesses and / or openings. These can perform a variety of functions, as will be explained below.

For example, breakthroughs can serve as ventilation openings for cooling the induction coil. Furthermore, material and weight can be saved. An embodiment of a support device with openings can be constructed, for example, in the manner of a spoked wheel, wherein the coil wire rests on the spokes. Likewise, there are further possibilities for an advantageous manufacturing method, which will be explained in detail later.

At least one of the support surfaces or both may be formed either substantially flat or without elevations. Alternatively, a number of elevations may be arranged on at least one of the support surfaces. These can determine the course of the coil wire as spacers or form a kind of Einbringungsnuten or prefabricated webs. This is especially advantageous if the position of the turns should be defined exactly to each other or especially if turns should not abut each other, but should have a certain distance from each other. These elevations may have an elongated structure and follow the coil turns or the gaps. However, they can also be used to save material from a series of adjacent, defining the spiral course arrangement.

The surveys can survive so far on a support surface of a support means that they form a certain stop for the coil wire. However, when introducing or winding the coil wire, it should still be possible to press it with a certain force through such a narrowed cross section in the inner region of the coil or the space between the support means. Especially a multi-strand coil wire has here an advantageous deformation ability. A reduction in area in the space through the bumps can range from about 10% to 20% lie. This is also considered sufficient to still effect a sufficient positional fixation.

The predeterminable by such surveys course of the induction coil or the coil wire may be such that in the central region either no distance or only a very small distance between adjacent turns prevails. To the outside, since above all a kind of power density of the induction heater can be defined, the distance increase.

The connection of the two support means to each other in a central or central area may, as stated previously, be integral. In addition, it is possible to provide after the winding of the induction coil in the outer region further connections or fixings, since then the gap no longer has to be accessible. A connector in the center may have a hole or hole to access this area. For example, a temperature sensor can be introduced therein, which measures the temperature above the induction coil. In particular, when using an induction heater in an induction cooktop, this is of interest to detect the temperature of a glass-ceramic cooktop panel passing over it or, indirectly, the temperature of an erected cooking vessel. In this case, fastening possibilities for a temperature sensor can be provided in the connecting piece, for example latching projections or recesses.

On an outer side or upper side of the carrier spacers odgl. be formed. With these, it can be applied, in particular as an induction heater in an induction hob cavity, with a precisely defined distance to the underside of a glass ceramic plate.

In a further embodiment of the invention, it is possible to form the aforementioned openings or openings in at least one of the support means so and to use it to bring spacers from the outside into the gap. This is particularly advantageous when adjacent turns of the induction coil have a certain distance from each other. Thus, after wrapping a turn on the radially outer side of a spacer can be introduced. Since it is inserted from outside through one of the support means, it does not hinder the introduction of the coil wire. The introduced spacer is advantageous to the inner winding or defines the radial distance of the outer winding. These spacers may in particular be rod-like or projection-like. Particularly advantageous they engage in both support means and are thus fixed. When the induction coil is wound up, they can remain in the carrier for a permanent shaping of the induction coil.

Apart from the induction coil itself, ferrites can be arranged on the support, for example on a lower side. In particular, they are relatively flat and run spoke- or star-like. They can be introduced or clamped or glued in corresponding receptacles on the underside of the support means.

In the manufacture of the induction coil, the winding is understandably carried out starting radially inside. Since a connection possibility must thus be created starting radially inward, an opening or a passage can be provided on one of the support devices, through which the beginning of the coil wire for the induction coil can be led to the outside. For simplified implementation of the coil wire, this implementation may be formed enlarged. Advantageously, it is elongate or a wide slot which extends radially into an outer region, in particular to just before the outer edge or even through it. Thus, the implementation of the coil wire is relatively easy. Furthermore, such a radially extending slot does not interfere with the support of the individual, in the circumferential direction and thus substantially transverse thereto coil turns. As previously stated, such a slot can also take over functions such as cooling air supply or the like.

After the introduction of one end of the induction coil or of the coil wire, the actual winding can begin. For this purpose, there are different possibilities, in particular, the carrier rotates with fixed coil wire feeder. Due to the precise definition of the height of the intermediate space between the support means or by the aforementioned elevations, it is possible that the coil wire is sufficiently accurately fixed in position only by clamping action. Thus, the induction coil can be made without gluing or other fasteners.

These and other features will become apparent from the claims and from the description and drawings, wherein the individual features each alone or more in the form of sub-combinations in one 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 as well as intermediate headings does not restrict the general validity of the statements made thereunder.

Brief description of the drawings

Fig. 1

einen seitlichen Schnitt durch einen Träger mit verschiedenen Ausbildungsmöglichkeiten bzw. Details;

Fig. 2

einen Träger entsprechend Fig. 1 mit aufgewickelter Induktionsspule und

Fig. 3

einen Schnitt durch eine Induktions-Kochfeldmulde mit unter einer Glaskeramik-Platte angeordneter Induktionsheizeinrichtung mit einer Induktionsspule entsprechend Fig. 2.

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

Fig. 1

a lateral section through a carrier with various training opportunities or details;

Fig. 2

a carrier according to FIG. 1 with wound induction coil and

Fig. 3

a section through an induction hob cavity with arranged under a glass ceramic plate induction heater with an induction coil according to FIG. 2.

Detailed description of the embodiments

In Fig. 1, an induction coil 11 is exemplified or different training options are illustrated. The induction coil 11 has a carrier 12. It consists of an upper plate 14 as an upper support means and a lower plate 15 as a lower support means. The two plates 14 and 15 are connected via a central piece 16, in particular the entire carrier 12 is integrally formed, for example made of plastic.

In the center piece 16 extends as a longitudinal bore a central recess 18. This can serve various functions, i.a. to do here a temperature sensor to perform on an overlying hob plate. Likewise, a cooling air flow can perform. The central recess 18 also serves to save material.

It is also possible to provide in the surface of one of the two plates 14 or 15 or in both plates ventilation openings 20 with webs 21 in between. They may be formed, for example, as extending in the radial direction slots. In addition to the function of improved ventilation, they can also be used to save material. Furthermore, it is also possible here to supply a feed to the winding of the coil wire between the plates 14 and 15. or lead out. Since there are still the webs 21 of the plates 14, 15 between the ventilation openings 20, sufficient support or securing of the turns 30 is still ensured here. For example, it is also possible to form vent holes 20 in the upper plate 14 offset from those in the lower plate 15. In any case, a sufficient support surface for the turns 30 is still created by the webs 21 and the outer circumferential edge in such a case.

Right is also exemplified on the support 12, as a vent on the right side as a slot 22 may be continuous or is open to the edge. In such a slot, an inner terminal end for the induction coil or the windings 30 is particularly advantageous inserted laterally.

Furthermore, it is shown in the left region of the carrier 12, as a bore 24 may be provided for a spacer 26. In this case, this bore 24 goes completely as a bore 24a through the upper plate 14 and extends partially as a lower bore 24b in the lower plate 15. In this bore 24, advantageously in a clamping manner, a spacer 26 is inserted. From the drain, this is done after introducing the right next to the spacer 26 shown inner winding 30. From the outside then the next outer winding 30 is wound on the left side of the spacer 26, so that then between the two turns a distance with the thickness of the spacer is complied with. By setting the holes 24 or thickness of the spacers 26 differently, the distances between adjacent turns can be varied.

An alternative method to the spacers 26 is shown in the right pane. There are the turns 30 in a central or central region of the induction coil directly next to each other or touch yourself. From about half the radius elevations 28 are provided, in the example shown on the support surface, which is formed by the lower plate 15. The bumps 28 become wider with increasing radius of the turns. As a result, the spacing of adjacent turns 30 becomes greater, which can be done inter alia to reduce the power density in the radially outer region.

The elevations 28 may be formed according to an embodiment as a longitudinal elevations, which extend spirally according to the course of the individual windings 30. You can either be trained throughout. Alternatively, they may be formed along such an imaginary line as individual elevations spaced from each other, thereby also forming a kind of line or a line-like stop for each individual turn.

The height of the elevations 28 is advantageous such that upon insertion of the coil wire 31 and the turns 30, these are introduced from radially outside. They are brought in with so much force that they just overcome so many elevations 28, until they come to lie in the right lane, so to speak. The elevations 28 may be provided either with a flat average increase. Preferably, as shown, they may be formed with triangular cross section, constant height and varying width. Thus, the turns 30 center themselves, so to speak at the lowest point between two elevations 28 in the desired position.

In Fig. 2, an induction coil 11 is shown in partial section with inserted turns 30 of coil wire 31. However, a constant distance of the turns 30 is provided here in comparison to the Fig. 1 or these are each exactly to each other. So there are no spacers 26 or similarly functioning elevations 28 are provided. It can also be seen how the thickness of the coil wire 31 in about the height of the groove 17 between the plates 14 and 15 corresponds. Thus, a very good positional fixation takes place.

Further, in Fig. 2, connections to the induction coil 11 are shown, namely, an outer terminal 32a and an inner terminal 32b. In particular, the inner terminal 32 b may be led out through a corresponding opening, for example a ventilation opening 20 or a slot 22 according to FIG. 1 on the lower plate 15.

In Fig. 3, an induction hob 35 is shown in section. Under a glass ceramic plate 36, an induction coil 11 is arranged. In this case, the carrier 12 and the upper plate 14 of the carrier spacer elements 38, which are formed as elevations. Thus, the induction coil 11 abuts the top of the plate 14 on the underside of the glass-ceramic plate 36.

The carrier 12 has, in a groove 17 similar to FIGS. 1 and 2, a plurality of turns 30 made of a coil wire 31. Corresponding terminals 32a and 32b are led out and in particular led into a supply 40, in which the induction coil 11 is subjected to power via the terminals 32. Further execution to the supply 40 are not necessary, since this connection is readily executable by a person skilled in the art.

In the middle of the support 12 extends through a central piece 16, a central recess 18. In this, a temperature sensor 42 is arranged. It lies with its upper part on the underside of the glass ceramic plate 36 and can detect their temperature. This serves in particular to avoid overheating of the glass ceramic plate and the temperature of a hot display or the like. of the hob 35 to give.

Similarly as the inner terminal 32b may be substantially fixed by a corresponding slot or opening in the lower plate 15, the outer terminal 32a may pass through a similar opening. Here, however, there is no fixation by radially outer subsequent turns 30, so that either a clamping in the slot in the lower plate 15 may be provided. Alternatively, a fixation can be carried out by gluing or by the supply of the connection 32a to a supply 40 according to FIG. 3, a position assurance can take place.

Claims (20)

Support for an induction coil (11) having a substantially flat extension, wherein the support (12) has an upper (14) and a lower support means (15) which are mechanically interconnected and form a narrow space (17) for introducing the induction coil, which is preferably a single continuous coil wire (31). Carrier according to claim 1, characterized in that it, in particular with the support means (14, 15) and a connecting piece (16) between them, is made in one piece and in one piece, preferably made of plastic. Carrier according to claim 1 or 2, characterized in that the distance between the two support means (14, 15) from each other in the range of the thickness of the coil wire (31), wherein preferably the distance is so large that the coil wire with slight clamping action between the support means lies. Carrier according to one of the preceding claims, characterized in that the support means (14, 15) form a respective inwardly or toward each other to be pointed support surface or extend in such a support surface. Carrier according to one of the preceding claims, characterized in that the support means (14, 15) are over the entire surface or of these for the coil wire (31) formed support surfaces are substantially closed. Carrier according to one of claims 1 to 4, characterized by recesses and / or openings (20, 22) in the support means (14, 15). Carrier according to one of the preceding claims, characterized in that support surfaces formed by the support means (14, 15) are flat or are formed without elevation. Carrier according to one of claims 1 to 7, characterized in that at least one of the support surfaces of the support means (14, 15) has elevations (28) which run along the intended course of the coil wire (31) or at intervals provided to define a Distance between two adjacent turns (30) of coil wires from each other, wherein in particular the elevations (28) act as spacers. Carrier according to claim 8, characterized in that the elevations (28) so far beyond a support surface of a support means (14, 15) and reduce the cross section of the intermediate space (17) that the coil wire (31) pressed by force application during winding or can be pushed past, wherein preferably the cross-sectional reduction is about 10% to 20%. Carrier according to claim 8 or 9, characterized in that elevations (28) are formed or arranged such that in the central region of the carrier (12) no or only a small distance between adjacent turns (30) is provided and in the outer region of the carrier Distance is greater, preferably the distance to the outside area becomes larger. Carrier according to one of the preceding claims, characterized in that the two support means (14, 15) are mechanically connected to each other in a central region, in particular by a connecting piece (16), wherein preferably in the central region an opening (18) is provided for introducing a Temperature sensor (42) or the like. Carrier according to one of the preceding claims, characterized in that in at least one of the support means (14, 15), preferably in both support means in the same way, openings or openings (24) are provided for insertion and permanent attachment of rod or projection-like spacers (26) which are radially outside of an inner turn (30) can be introduced before the introduction of the subsequent radially outer winding (30) and thus the distance of adjacent turns (30) to each other. An induction heating device comprising an induction coil (11) and a support (12) according to any one of the preceding claims therefor. Induction heater according to claim 13, characterized in that the coil wire (31) is secured without glue or exclusively by mechanical pressing on the support (12). Induction hob with at least one induction heating device (11) according to claim 13 or 14. Method for producing an induction coil (11), characterized in that it is mounted on a support (12) according to one of the claims 1 to 12 radially inside starting a coil wire (31) in the space (17) between the support means (14, 15) is wrapped, wherein radially from the inside to the outside is wound. A method according to claim 16, characterized in that an electrical connection (32b) to the inner end of the induction coil (11) through a recess (20, 22) in the carrier (12) or one of the support means (15) is passed before the beginning of the Winding the induction coil, wherein the recess is considerably larger than the cross section of the coil wire (31) and in particular elongated, wherein it extends longitudinally in the radial direction from a starting point (32b) of the coil winding in the outward direction. A method according to claim 16 or 17, characterized in that the support (12) according to one of claims 1 to 12 is formed and from a certain winding radius spacers (26) are introduced before the application of the next outer Windungsabschnittes (30), preferably the Spacers are introduced directly after wrapping the previous radially inner winding section (30). Method according to one of claims 16 to 18, characterized in that starting from a certain coil radius, preferably from about one third or half, parallel and simultaneously as well as radially inwardly with the coil wire (31) an elongated flexible spacer is wound up, whose thickness or Cross-section increases with the number of applied turns or radial extent of the induction coil (11). Method according to one of claims 16 to 19, characterized in that the carrier (12) is rotated with a fixed coil wire feed.

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