Induction heating equipment, production line, use of this type of induction heating equipment, and use of this type of production line

Abstract

The present invention relates to an induction heating device (1) for heating a metal material (40) being transported in a transport direction (R1), wherein the induction heating device (1) comprises at least one inductor (2) having at least one first coil (10) and at least one second coil (20), the first coil (10) and the second coil (20) being spaced apart from each other in a separation direction (R2) and defining at least a partial gap between them, thereby allowing the metal material (40) being transported in the transport direction (R1) to be transported at least partially through the gap between the first coil (10) and the second coil (20), and at least one energy supply means (30) electrically connected to the first coil (10) and the second coil (20).

Description

[Technical Field]

[0001] The present invention relates to an induction heating apparatus for heating a metal material, and to a manufacturing line for manufacturing and / or processing a metal material.

[0002] The present invention also relates to the use of such induction heating devices or production lines. [Background technology]

[0003] Induction heating devices for heating metallic materials are generally known from the prior art, particularly in connection with manufacturing lines for producing and / or processing metallic materials. In this case, known induction heating devices for heating metallic materials being transported in a transport direction include a coil fixed to the metallic material and / or a coil that is movable perpendicular to the transport direction of the metallic material, and the metallic material is induced to pass through the coils of the induction heating device in the transport direction.

[0004] Furthermore, known induction heating devices can be fundamentally distinguished depending on whether the coil of the induction heating device can generate longitudinal magnetic field induction or transverse magnetic field induction. In longitudinal magnetic field induction, the magnetic field lines extend substantially in the longitudinal direction of the extension of the metallic material. In transverse magnetic field induction, the magnetic field lines within the metallic material extend substantially in the transverse direction of the extension of the metallic material, particularly in the thickness direction and / or width direction of the extension of the metallic material. With longitudinal magnetic field induction, improved heating uniformity is achieved, while with transverse magnetic field induction, overheating or overcooling can occur, particularly in the edge regions of the metallic material.

[0005] Induction heating devices for generating longitudinal magnetic field induction have coils, particularly fixed coils, and the vertical distance between the fixed coil and the metal material is generally configured such that the metal material does not collide with the fixed coil when viewed laterally with respect to the transport surface of each induction heating device. Since induction heating devices are intended for use with various metal materials having different dimensions, the standard vertical safety distance between coils is regularly maintained to avoid unintended damage to the coils. However, this intended, and usually the largest possible, standard vertical safety distance significantly reduces the electrical efficiency of each induction heating device. [Overview of the project] [Problems that the invention aims to solve]

[0006] The present invention aims to provide an induction heating device that has high electrical efficiency between the coil and the metal material, and simultaneously improves the uniformity of heating the metal material during induction heating of the metal material. [Means for solving the problem]

[0007] This fundamental objective of the present invention is achieved by an induction heating apparatus having the features of claim 1, a manufacturing line having the features of claim 14, and the use described in claim 15. Advantageous embodiments of the induction heating apparatus are described in the dependent claims.

[0008] More specifically, the fundamental objective of the present invention is achieved by an induction heating device for heating a metal material being transported in a transport direction, the induction heating device having at least one inductor having at least one first coil and at least one second coil. The first coil and the second coil are spaced apart from each other in the distance direction, defining at least a partial gap, so that the metal material being transported in the transport direction is transported through the gap between the first coil and the second coil. The induction heating device further has an energy supply means electrically connected to the first coil and the second coil, the energy supply means configured to supply alternating current and / or alternating voltage to the first coil and the second coil such that the penetration depth δ of the energized layer of the transported metal material is 0.7 times or less the thickness extension of the transported metal material.

[0009] The current density of the current induced by the alternating magnetic fields of the first and second coils within the metallic material being transported through the space between the first and second coils decreases from each surface of the metallic material through the extension of the metallic material's thickness. The penetration depth δ of the current-carrying layer is defined as the penetration depth at which the current density of the induced current decreases from the surface of the metallic material to 1 / e of the current density of the induced current at the surface of the metallic material, where e is Euler's number. The penetration depth δ is determined according to equation (1) below.

[0010]

number

[0011] The penetration depth δ increases as the frequency of the induced current decreases. Consequently, the current density of the induced current decreases more slowly from the surface of the metal material down to its thickness as the frequency of the induced current decreases. As a result, deeper layers of the metal material are heated in addition to the surface, thus improving heating uniformity along with the thickness expansion of the metal material.

[0012] According to equation (1), the penetration depth δ of the current-carrying layer of the conveyed metal material is determined by the frequency of the alternating current flowing through the first and second coils, and the relative permeability μ. r It is found that this depends on the material of the metallic material being transported. The energy supply means configured to supply alternating current and alternating voltage to the first and second coils so that a defined penetration depth δ of the current-carrying layer in the transported metallic material is achieved is consequently configured to supply alternating current and alternating voltage of appropriate frequency to the first and second coils. The known relative permeability μ of the transported metallic material r Using this, the penetration depth δ can be adjusted according to equation (1).

[0013] The energy supply means may be configured to supply alternating current and / or alternating voltage to the first coil and the second coil such that the penetration depth δ of the energized layer of the conveyed metal material is 0.6 times or less, 0.5 times or less, 0.45 times or less, 0.4 times or less, 0.35 times or less, or 0.3 times or less the thickness extension of the conveyed metal material.

[0014] The induction heating apparatus designed in this manner has been shown to have the advantage of achieving high electrical efficiency between the coil and the metal material during induction heating of the metal material, and at the same time, improving the uniformity of heating of the metal material, particularly in the thickness stretching of the metal material.

[0015] According to a preferred embodiment, the energy supply means is configured to supply an alternating current and / or an alternating voltage to the first coil and the second coil such that the penetration depth δ of the energized layer of the metal material being conveyed is not more than 0.6 times and not less than 0.3 times, not more than 0.5 times and not less than 0.3 times, not more than 0.6 times and not less than 0.4 times, not more than 0.5 times and not less than 0.4 times, not more than 0.45 times and not less than 0.3 times, or not more than 0.4 times and not less than 0.3 times of the thickness extension of the metal material. According to a particularly preferred embodiment, the energy supply means may be configured to supply an alternating current and / or an alternating voltage to the first coil and the second coil such that the penetration depth δ of the energized layer of the metal material being conveyed is in the range of not more than 0.45 times and not less than 0.4 times of the thickness extension of the metal material.

[0016] It has been shown that the induction heating device designed in this way has the advantage that during the induction heating of the metal material, a further improvement in the electrical efficiency between the coil and the metal material is achieved, and at the same time, a further improvement in the heating uniformity of the metal material, particularly in the thickness extension of the metal material, is achieved.

[0017] According to a particularly preferred embodiment, the energy supply means may be configured to supply an alternating current and / or an alternating voltage to the first coil and the second coil, as a result of which the penetration depth δ of the energized layer of the metal material being conveyed is equal to 0.45 times the thickness extension of the metal material being conveyed.

[0018] It has been shown that the induction heating device designed in this way has the advantage that during the induction heating of the metal material, a particularly high electrical efficiency between the coil and the metal material is achieved, and at the same time, a particularly increased heating uniformity of the metal material, particularly in the thickness extension of the metal material, is achieved.

[0019] The electrical efficiency between the coil and the metal material is determined according to the following formula (2) from the power converted by the metal material and the power loss of the coil.

[0020]

Equation

[0021] The "energy supply means" is understood to mean a device designed to supply power for operating at least one resonant circuit, particularly a current having an appropriate current intensity, an appropriate voltage, and / or an appropriate frequency. The energy supply device of the present invention can be designed to supply power to a plurality of coils, particularly at least two coils, preferably three, four, five, six, or more coils. The energy supply means can have, or can be designed to have, at least one power converter, particularly an inverter.

[0022] The metal material can be in the form of a substantially flat workpiece. The metal material can be in the form of a metal slab, a metal strip, or a formed blank. The formed blank can be any semi-finished product for the manufacture of metal materials, particularly for the manufacture of metal forming sheets such as automotive body parts. Alternatively, the metal material can be a finished automotive body part, for example, a body sheet metal part of an automotive A-pillar or B-pillar.

[0023] A substantially flat workpiece in the context of the present invention has a thickness extension that is substantially smaller than the width extension and the length extension.

[0024] The length of the metal material is the length in the conveying direction of the metal material.

[0025] The thickness extension of the metal material is the extension of the metal material in the separation direction.

[0026] The transverse direction extends perpendicular to the conveying direction and the separation direction. In other words, the conveying direction, the separation direction, and the transverse direction form an orthogonal coordinate system.

[0027] The widthening of a metallic material is the stretching of the metallic material in the lateral direction.

[0028] The conveying direction and the lateral direction extend across the conveying surface. The planes that extend due to the lengthening and widthening of the metal material are aligned parallel to the conveying surface. Preferably, the conveying surface is positioned symmetrically with respect to the center of the metal material with respect to the thicknessening of the metal material.

[0029] Generally, the conveying direction is aligned horizontally. In this respect, the transverse direction is also horizontal and perpendicular to the conveying direction, and as a result, the conveying surface is aligned horizontally. Therefore, the separation direction is aligned vertically and perpendicular to both the conveying direction and the separation direction.

[0030] The conveying direction can be aligned vertically. In this respect, the lateral direction is aligned horizontally and perpendicular to the conveying direction, and as a result, the conveying surface is aligned vertically. Therefore, the separation direction is aligned horizontally and perpendicular to both the conveying direction and the separation direction.

[0031] The metallic material has a first surface and a second surface opposite to the first surface. The separation direction is aligned perpendicular to the first and second surfaces of the metallic material.

[0032] When the conveying direction is aligned horizontally, the first surface of the metal material may be referred to as the top surface, and the second surface of the metal material may be referred to as the bottom surface. The first coil may be positioned above the conveyed metal material, particularly opposite the top surface of the metal material. The second coil may be positioned below the conveyed metal material, particularly opposite the bottom surface of the metal material. The first coil may also be referred to as the upper coil, and the second coil may also be referred to as the lower coil.

[0033] Metal materials can be conveyed along a conveyor line in the conveying direction. The conveyor line can be designed as a conveyor belt.

[0034] The first coil and / or the second coil may be mounted so as to be movable in the transport direction and / or the separation direction and / or the lateral direction.

[0035] The first coil and the second coil are positioned at the same location in the conveying direction, and may be positioned opposite each other in the separating direction so that they can convey the metal material being conveyed in the conveying direction while sandwiching it between them.

[0036] The first coil and the second coil may be positioned in the same location in the direction of transport and / or the lateral direction, so that the coils substantially coincide with the transport surface.

[0037] The first coil and the second coil may have substantially the same shape.

[0038] Preferably, the induction heating device is designed such that the first coil is at a first distance of 150 mm or less in the direction away from the first surface of the metal material being conveyed, and / or the second coil is at a second distance of 150 mm or less in the direction away from the second surface of the metal material being conveyed.

[0039] Induction heating devices designed in this way have the advantage of achieving high electrical efficiency between the coil and the metal material during induction heating of the metal material. The smaller the distance between the coil and the metal material in the separation direction, the lower the stray magnetic field loss and the better the coupling of the magnetic field generated by the coil to the metal material, thus increasing the electrical efficiency between the coil and the metal material.

[0040] The first and second surfaces of the metallic material are preferably opposite surfaces of the metallic material. The first and second surfaces of the metallic material can be aligned at least partially parallel, preferably substantially parallel, to the conveying surface. The first and second surfaces define the metallic material in the thickness stretching of the metallic material. If the metallic material has a conveying direction aligned horizontally, the first surface is the top surface of the metallic material and the second surface is the bottom surface of the metallic material. The bottom surface of the metallic material is particularly facing the ground. In the case of a metallic material formed as a metal slab or metal strip, the first surface lies in a plane parallel to the conveying surface and defines the metallic material in one direction of thickness stretching of the metallic material. The second surface of the metallic material lies opposite the first surface in a further plane parallel to the conveying surface and defines the metallic material in the opposite direction of thickness stretching of the metallic material.

[0041] The first coil may be at a first distance of 100 mm or less, 75 mm or less, 50 mm or less, 40 mm or less, 25 mm or less, 20 mm or less, 15 mm or less, or 10 mm or less in the direction away from the first surface of the metal material being conveyed.

[0042] The first coil may be at a first distance of 100 mm or less and 10 mm or more, 75 mm or less and 15 mm or more, 50 mm or less and 20 mm or more, or 40 mm or less and 25 mm or more in the direction away from the first surface of the metal material being conveyed.

[0043] The second coil may be at a second distance of 100 mm or less, 75 mm or less, 50 mm or less, 40 mm or less, 25 mm or less, 20 mm or less, 15 mm or less, or 10 mm or less from the second surface of the metal material being conveyed.

[0044] The second coil may be at a second distance of 100 mm or less and 10 mm or more, 75 mm or less and 15 mm or more, 50 mm or less and 20 mm or more, or 40 mm or less and 25 mm or more in the direction away from the second surface of the metal material being conveyed.

[0045] The first distance of the first coil from the first surface of the metal material being transported may correspond to the second distance of the second coil from the second surface opposite the first surface of the metal material. In other words, the first distance and the second distance may have the same absolute value.

[0046] The induction heating device is preferably designed such that the first coil has at least one turn formed by at least two first conductor profiles connected via a first connecting web, and the first connecting web of the first coil is at a first edge distance from the first outer edge of the metal material being conveyed that is no more than five times the extension of the gap d between the first coil and the second coil, and / or the second coil has at least one turn formed by at least two second conductor profiles connected via a second connecting web, and the second connecting web of the second coil is at a second edge distance from the first outer edge of the metal material being conveyed that is no more than five times the extension of the gap d between the first coil and the second coil.

[0047] An induction heating apparatus designed in this manner has the advantage of achieving improved heating uniformity during induction heating of metal materials, particularly improved heating uniformity during the width stretching of metal materials.

[0048] In longitudinal magnetic field induction, the current induced by the first coil in the metallic material flows in the opposite direction to the current induced by the second coil. The current induced in the metallic material by the first coil flows in the width-extending direction on the first surface of the metallic material and merges with the current induced in the metallic material by the second coil via the first outer edge of the metallic material. The current induced in the metallic material by the second coil flows along the width of the metallic material on the second surface of the metallic material in the opposite direction to the current induced by the first coil, and then merges with the current induced by the first coil via the second outer edge of the metallic material. As a result, the induced currents of the first and second coils form a closed circuit in a plane perpendicular to the transport direction of the metallic material. Therefore, in particular, no current is induced in the transport direction at the first and / or second outer edges. This prevents overheating of the outer edges, and as a result, the metallic material exhibits improved heating uniformity across its width during induction heating.

[0049] The metallic material preferably has a second outer edge. The first and second outer edges are preferably on opposite sides of the metallic material. The first and second outer edges of the metallic material define the metallic material in the width extension of the metallic material. The first and second outer edges extend at least partially parallel, preferably substantially parallel, to the planes extending in the transport direction and the separation direction. In the case of a metallic material formed as a metal slab or metal strip, the first and second outer edges are positioned substantially perpendicular to the first and second surfaces of the metallic material. The first and second outer edges may also be referred to as sides of the metallic material, particularly in the case of a metallic material formed as a metal slab or metal strip.

[0050] The first connecting web of the first coil may be at a first edge distance from the first outer edge of the conveyed metal material that is 4 times, 3 times, 2 times, or 1.5 times the elongation of the gap d between the first coil and the second coil.

[0051] The first connecting web of the first coil may be at a first edge distance from the first outer edge of the conveyed metal material that is 0 times or more, 0.5 times or more, 1 time or more, or 1.5 times or more the elongation of the gap d between the first coil and the second coil.

[0052] An induction heating apparatus designed in this manner has the advantage of achieving high electrical efficiency between the coil and the metal material during induction heating of the metal material, while simultaneously improving the uniformity of heating the metal material, particularly in the stretching of the metal material.

[0053] According to a preferred embodiment, the first connecting web of the first coil may be at a first edge distance from the first outer edge of the conveyed metal material within the range of 0.5 to 3 times, 1 to 3 times, and 1 to 2 times the elongation of the gap d between the first coil and the second coil.

[0054] An induction heating apparatus designed in this manner has the advantage of achieving particularly high electrical efficiency between the coil and the metal material during induction heating of the metal material, and at the same time, particularly increased heating uniformity of the metal material, especially in the width stretching of the metal material.

[0055] The second connecting web of the second coil may be at a second edge distance from the first outer edge of the conveyed metal material that is 4 times, 3 times, 2 times, or 1.5 times the elongation of the gap d between the first coil and the second coil.

[0056] The second connecting web of the second coil may be at a second edge distance from the first outer edge of the conveyed metal material that is 0 times or more, 0.5 times or more, 1 time or more, or 1.5 times or more the elongation of the gap d between the first coil and the second coil.

[0057] According to a preferred embodiment, the second connecting web of the second coil may be at a second edge distance from the first outer edge of the conveyed metal material within the range of 0.5 to 3 times, 1 to 3 times, and 1 to 2 times the elongation of the gap d between the first coil and the second coil.

[0058] The first and / or second edge distances are aligned laterally.

[0059] The first connecting web of the first coil, together with the two first conductor profiles of the first coil, forms a turn with respect to the space between the two first conductor profiles. The second connecting web of the second coil, together with the two second conductor profiles of the second coil, forms a turn with respect to the space between the two second conductor profiles.

[0060] A first connecting web can be connected to two first conductor profiles such that the first coil has a U-shape. A second connecting web can be connected to two second conductor profiles such that the second coil has a U-shape.

[0061] The first edge distance can substantially correspond to the second edge distance. In other words, the first and second edge distances can have the same absolute distance value.

[0062] The gap d between the first coil and the second coil is the absolute distance between the first coil and the second coil in the direction of separation. In other words, the elongation of the gap d corresponds to the sum of the first distance, the thickness elongation of the metal material, and the second distance.

[0063] The gap d between the first coil and the second coil can have a range of 350 mm or less, 300 mm or less, 250 mm or less, 200 mm or less, 150 mm or less, or 100 mm or less in the direction of separation. The gap d between the first coil and the second coil can have an extension of 350 mm or more, 300 mm or more, 250 mm or more, 200 mm or more, 150 mm or more, or 100 mm or more in the direction of separation.

[0064] The gap d between the first coil and the second coil can have an elongation in the separating direction of 350 mm or less and 100 mm or more, 300 mm or less and 150 mm or more, 250 mm or less and 150 mm or more, or 250 mm or less and 200 mm or more.

[0065] The distance space defined at least partially by the first coil and the second coil can also be called the electrically effective range. Within the electrically effective range, the magnetic fields generated by the first and second coils can interact with the metallic material. The gap d can form an extension of the gap space in the direction of separation.

[0066] The induction heating device is preferably designed such that at least two first conductor profiles of a first coil are at a first pole distance of no more than four times the extension of the air gap d from each other, and / or at least two second conductor profiles of a second coil are at a second pole distance of no more than four times the extension of the air gap d from each other.

[0067] The pole distance between two electrically connected conductor profiles in a coil is the distance between the two conductor profiles in the transport direction.

[0068] An induction heating apparatus designed in this manner has the advantage of achieving improved heating uniformity during induction heating of metal materials, particularly across the width of the metal material.

[0069] The currents induced in the metal material by the first and second coils flow in opposite directions to the currents flowing through the two first conductor profiles of the first coil and the currents flowing through the two second conductor profiles of the second coil. As the pole distance between the two conductor profiles of the coils increases, the mutual influence of the induced currents of the coils decreases, and the electrical efficiency between the coils and the metal material increases. Due to the reduced mutual influence of the currents induced in the metal material by the two conductor profiles of the coils, the current induced in the metal material by the first coil merges with the current induced in the metal material by the second coil through the first and second outer edges, forming a closed current circuit in a plane perpendicular to the transport direction of the metal material. Therefore, in particular, no current is induced in the transport direction at the first and / or second outer edges. This prevents overheating of the outer edges, and as a result, the heating uniformity across the width of the metal material is improved during induction heating.

[0070] The two first conductor profiles may be at first pole distances from each other of no more than 3 times, 2.6 times, 2.4 times, or 2.2 times the extension of the gap d.

[0071] An induction heating apparatus designed in this manner has the advantage of achieving high electrical efficiency between the coil and the metal material during induction heating of the metal material, while simultaneously improving the uniformity of heating the metal material, particularly in the stretching of the metal material.

[0072] The two first conductor profiles may be at first pole distances from each other of 0.5 times, 1 time, 1.5 times, or 1.8 times the extension of the gap d.

[0073] According to a preferred embodiment, the two first conductor profiles may be separated from each other by a first pole distance within the range of 0.5 to 4 times, 1 to 3 times, 1.5 to 2.5 times, 1.8 to 2.5 times, or 1.8 to 2.2 times the elongation of the gap d.

[0074] An induction heating apparatus designed in this manner has the advantage of achieving particularly high electrical efficiency between the coil and the metal material during induction heating of the metal material, and at the same time, particularly increased heating uniformity of the metal material, especially increased heating uniformity in the width stretching of the metal material.

[0075] The two second conductor profiles can be at second pole distances from each other of no more than 3 times, 2.6 times, 2.4 times, or 2.2 times the extension of the gap d.

[0076] The two second conductor profiles can be at a second pole distance from each other of 0.5 times, 1 time, 1.5 times, or 1.8 times the extension of the air gap d.

[0077] According to a preferred embodiment, the two second conductor profiles may be separated from each other by a second pole distance within the range of 0.5 to 4 times, 1 to 3 times, 1.5 to 2.5 times, 1.8 to 2.5 times, or 1.8 to 2.2 times the elongation of the gap d.

[0078] The first coil can be arranged such that the two first conductor profiles face each other with respect to a plane that extends in the separating direction and the lateral direction. In the horizontal transport direction, the first coil can be arranged such that the two first conductor profiles are arranged successively in the transport direction.

[0079] The second coil may be arranged such that the two second conductor profiles face each other with respect to a plane that extends in the interleaving and transverse directions. In the horizontal transport direction, the second coil may be arranged such that the two second conductor profiles are arranged successively in the transport direction.

[0080] The two first conductor profiles are preferably welded to a first connecting web and more preferably monolithically connected. The two second conductor profiles are preferably welded to a second connecting web and more preferably monolithically connected.

[0081] The conductor profiles of the first coil and / or the second coil may have a rectangular profile cross-section in the cross-sectional plane extending in the transport direction and the separation direction. The connecting webs of the first coil and / or the second coil may have a rectangular profile cross-section in the cross-sectional plane extending in the transverse and separation directions.

[0082] The conductor profiles of the first coil and / or the second coil may have a hollow profile cross-section, preferably a rectangular hollow profile cross-section, in a cross-sectional plane extending in the transport direction and the separation direction.

[0083] The connecting webs of the first coil and / or the second coil may have hollow profile cross-sections, preferably rectangular hollow profile cross-sections, in a cross-sectional plane that extends in the transverse and space-apart directions.

[0084] The free cross-section of the conductor profile and connecting web of the first coil can be designed as the first cooling fluid channel, and the free cross-section of the conductor profile and connecting web of the second coil can be designed as the second cooling fluid channel of the second coil. In other words, the conductor profile and connecting web of the first coil and / or the second coil can each define a cooling fluid channel.

[0085] The induction heating apparatus may have a cooling apparatus, which has at least a first cooling circuit having a first inlet and a first outlet fluidly connected to the first inlet via a first cooling fluid channel. In other words, the first cooling circuit may extend at least partially through a first cooling fluid channel inside the first coil.

[0086] The first cooling circuit may further include a second inlet and a second outlet fluidly connected to the second inlet via a second cooling fluid channel. In other words, the first cooling circuit may extend at least partially through the second cooling fluid channel inside the second coil.

[0087] The cooling device may have at least one second cooling circuit having a second inlet and a second outlet fluidly connected to the second inlet via a second cooling fluid channel. In other words, the cooling circuit extends at least partially through the second cooling fluid channel inside the second coil.

[0088] The cooling system can be designed to provide a cooling capacity of 500 kW, 750 kW, or 1,000 kW or more over a period of at least one hour per day, preferably 23 hours. The cooling system can be configured to provide a cooling force of 20% or more, preferably 30% or more, of the power provided by the energy supply means for the first coil and / or the second coil.

[0089] The conductor profiles and connecting webs of the first and / or second coils may have substantially constant wall thickness. The wall thickness can be designed in accordance with the electrical penetration depth of the current flowing through the conductor profiles and the connecting webs of the first and / or second coils. The wall thickness may be at least twice the electrical penetration depth, preferably at least three times the electrical penetration depth, and particularly preferably at least four times the electrical penetration depth.

[0090] The conductor profiles and connecting webs of the first coil and / or the second coil may have a separation direction extension of 40 mm or less, preferably 35 mm or less, and particularly preferably 30 mm or less.

[0091] The conductor profiles of the first coil and / or the second coil may have an elongation in the transport direction of 60 mm or less, preferably 55 mm or less, and particularly preferably 50 mm or less.

[0092] The connecting webs of the first coil and / or the second coil may have a transverse extension of 60 mm or less, preferably 55 mm or less, and particularly preferably 50 mm or less.

[0093] In a particularly preferred embodiment, the induction heating device is configured such that the energy supply means supplies alternating current and / or alternating voltage to a first coil and a second coil, so that the penetration depth δ of the energized layer of the conveyed metal material is in the range of 0.6 to 0.3 times the thickness of the metal material, the first connecting web of the first coil is at a first edge distance from the first outer edge of the conveyed metal material in the range of 0.5 to 3 times the extension of the gap d between the first coil and the second coil, the second connecting web of the second coil is at a second edge distance from the first outer edge of the conveyed metal material in the range of 0.5 to 3 times the extension of the gap d between the first coil and the second coil, the two first conductor profiles are at a first pole distance from each other in the range of 0.5 to 4 times the extension of the gap d, and the two second conductor profiles are at a second pole distance from each other in the range of 0.5 to 4 times the extension of the gap d.

[0094] It has been shown that induction heating devices designed in this manner have the advantage of achieving particularly increased electrical efficiency between the coil and the metal material during induction heating of the metal material, and at the same time, increased heating uniformity of the metal material during thickness stretching and width stretching.

[0095] In a more particularly preferred embodiment, the induction heating device is configured such that the energy supply means supplies alternating current and / or alternating voltage to the first coil and the second coil, and as a result the penetration depth δ of the energized layer of the conveyed metal material is in the range of 0.45 times or less and 0.4 times or more the thickness of the metal material, and the first connecting web of the first coil is in the range of 1 time or more and 2 times or less the extension of the gap d between the first coil and the second coil from the first outer edge of the conveyed metal material. The design is such that the edge distance is 1, the second connecting web of the second coil is at a second edge distance from the first outer edge of the conveyed metal material in a range of at least 1 and at least 2 times the extension of the gap d between the first coil and the second coil, the two first conductor profiles are at a first pole distance from each other in a range of at least 1.8 and at least 2.2 times the extension of the gap d, and the two second conductor profiles are at a second pole distance from each other in a range of at least 1.8 and at least 2.2 times the extension of the gap d.

[0096] It has been shown that induction heating devices designed in this manner have the advantage of achieving even greater electrical efficiency between the coil and the metal material during induction heating of the metal material, and at the same time, achieving even greater heating uniformity of the metal material in terms of thickness and width stretching.

[0097] The induction heating device is preferably designed such that the energy supply means is suitable for supplying an AC current and / or AC voltage frequency of 100 kHz or less to the first coil and the second coil.

[0098] The energy supply means may be suitable for, or configured for, supplying, an AC current and / or AC voltage frequency of 50 kHz or less, preferably 25 kHz or less, and particularly preferably 10 kHz or less to the first coil and the second coil.

[0099] The energy supply means may be suitable for, or configured to, supply an AC current and / or AC voltage frequency of 0.1 kHz or higher, preferably 0.5 kHz or higher, and particularly preferably 1 kHz or lower to the first and second coils. According to a preferred embodiment, the energy supply means may be suitable for, or configured to supply an AC current and / or AC voltage frequency in the range of 0.5 kHz to 50 kHz to the first and second coils. According to a particularly preferred embodiment, the energy supply means may be suitable for, or configured to supply an AC current and / or AC voltage frequency in the range of 1 kHz to 10 kHz to the first and second coils.

[0100] The induction heating device is preferably designed such that the energy supply means is suitable or configured to supply at least 1,000 kW of power to the first coil and / or the second coil over a period of at least 1 minute, and / or the first coil and / or the second coil are suitable or configured to absorb at least 1,000 kW of power over a period of at least 1 minute.

[0101] The energy supply means is suitable for, or may be configured for, supplying at least 1,000 kW of power to the first coil and / or the second coil for a period of 23 hours each, particularly for a period of 23 hours per day.

[0102] The first coil surface can be formed by a surface facing the first surface of the metallic material in the first conductor profile of the first coil.

[0103] The first coil surface has a power consumption of 400 W / cm² at the first coil surface. 2 The following is preferably 500 W / cm² 2It can be designed to provide the following power density. In other words, the first conductor profile can have an extension in the conveying direction and an extension in the transverse direction, and as a result, the first coil surface designed in this way is formed.

[0104] The first coil surface may further have a surface facing the first surface of the metal material in the first connection web.

[0105] The second coil surface can be formed by the surface facing the second surface of the metal material in the second conductor profile of the second coil.

[0106] [ The second coil surface is such that the power consumption of the second coil is 400 W / cm at the second coil surface <00,00009>Preferably 500 W / cm or less hereinafter 2 It can be designed to provide the following power density. In other words, the second conductor profile can have an extension in the conveying direction and an extension in the transverse direction, and as a result, the second coil surface designed in this way is formed. [[ID=,18]]

[0107] The second coil surface may further have a surface facing the second surface of the metal material in the second connection web.

[0108] The induction heating device is preferably designed such that the induction heating device displaces at least one first coil and / or at least one second coil of the inductor in the separation direction and / or the transverse direction and / or the conveying direction of the metal material, particularly having a displacement device suitable for displacing at least one first coil and / or at least one second coil of the inductor to the working position.

[0109] The displacement device can be configured to move at least one first coil and / or at least one second coil of the inductor in the separation direction and / or the transverse direction and / or the conveying direction of the metal material, particularly to displace the metal material to the working position.

[0110] At the working position, electrical connections can be established between the first coil and the metal material, and between the second coil and the metal material. In particular, at the working position of the induction heating device, the metal material is transported between the first coil and the second coil.

[0111] The displacement device can be configured to reduce and / or increase a first distance between the first coil and the first surface of the conveyed metal material, and / or a second distance between the second coil and the second surface of the conveyed metal material.

[0112] Preferably, the induction heating device is designed such that the first coil has a first core, the first core is arranged to form a magnetic path for the magnetic flux generated by the alternating current flowing through the first coil when an alternating current flows through the first coil, and / or the second coil has a second core, the second core is arranged to form a magnetic path for the magnetic flux generated by the alternating current flowing through the second coil when an alternating current flows through the second coil.

[0113] An induction heating device designed in this manner has the advantage of reducing the stray magnetic flux of the alternating magnetic field generated by the first and / or second energizing coils. The magnetic field lines are induced through the magnetic paths formed by the first and / or second cores, and thus the magnetic flux is directed more intensely toward the metallic material. As a result, the induction heating device exhibits improved electrical efficiency between the coils and the metallic material.

[0114] The first core and / or the second core may have metal or be formed from metal. The first core and / or the second core may have ferrite iron powder in a resin matrix or be formed from ferrite iron powder in a resin matrix.

[0115] The first coil may have two first cores, each first core surrounding at least a portion of the first conductor profile. The first cores can at least partially, preferably completely, surround the first conductor profile in a cross-section in a cross-sectional plane that extends in the transport direction and the separation direction. The surfaces of the first conductor profile facing the first surface of the metallic material may preferably not include the material of the first core.

[0116] The second coil may have two second cores, each second core at least partially surrounding the second conductor profile. The second core can at least partially, preferably completely, surround the second conductor profile in a cross-section in a cross-sectional plane extending in the transport and separation directions. The surfaces of the second conductor profile facing the second surface of the metallic material may preferably not include the material of the second core.

[0117] An induction heating device designed in this way has the advantage of further reducing the stray magnetic flux of the alternating magnetic field generated by the first and / or second energizing coils. As a result, it becomes an induction heating device with even higher electrical efficiency between the coil and the metal material.

[0118] The first core can at least partially surround the first conductor profile along the lateral direction. In particular, the first core can surround the first conductor profile along the lateral direction over a length range greater than or equal to the width of the conveyed metal material, preferably greater than or equal to the sum of the width of the conveyed metal material and the first edge distance.

[0119] The second core can at least partially surround the second conductor profile along the lateral direction. In particular, the second core can surround the second conductor profile along the lateral direction over a length range greater than or equal to the width of the conveyed metal material, preferably greater than or equal to the sum of the width of the conveyed metal material and the second edge distance.

[0120] The first core can form a coherent component together with the first coil.

[0121] The induction heating device is preferably designed to have at least one first capacitor device, the first capacitor device being connected to at least one first coil to form a first partial resonant circuit, and / or one first capacitor device being connected to at least one second coil to form a second partial resonant circuit, and / or having at least one second capacitor device, the second capacitor device being connected to at least one second coil to form a second partial resonant circuit.

[0122] The first capacitor means and / or the second capacitor means may have a single capacitor. Alternatively, the first capacitor device and / or the second capacitor device may have multiple capacitors connected in parallel and / or in series with respect to each other.

[0123] Preferably, the induction heating device is designed to have at least one matching transformer, the matching transformer being at least indirectly electrically connected on its secondary side to at least one first coil and / or at least one second coil.

[0124] The matching transformer can be directly electrically connected on its secondary side to the first capacitor device and / or the second capacitor device, preferably by cable, and more preferably by busbar.

[0125] The matching transformer can be connected to an energy supply means at least indirectly, preferably directly, on its primary side.

[0126] Matched transformers can be designed as dry transformers. Alternatively, matched transformers can be designed as water-cooled transformers, particularly as water-cooled autotransformers, or as water-cooled isolated transformers. In particular, matched transformers can be designed to provide two AC currents and AC voltages that are 180° out of phase.

[0127] The induction heating device is preferably configured such that the energy supply means is set to supply alternating current to at least one first coil and at least one second coil, and the alternating current of at least one first coil and at least one second coil have the same phase or phase shift relative to each other, and the energy supply means is set to supply alternating voltage to at least one first coil and at least one second coil, and the alternating voltage of at least one first coil and at least one second coil have the same phase or phase shift relative to each other.

[0128] The energy supply means may be configured to supply alternating current to at least one first coil and at least one second coil, wherein the alternating current of at least one first coil and the alternating current of at least one second coil have a phase shift of 180° relative to each other.

[0129] The energy supply means may be configured to supply an AC voltage to at least one first coil and at least one second coil, wherein the AC voltage of at least one first coil and the AC voltage of at least one second coil have a phase shift of 180° relative to each other.

[0130] An induction heating device having such an energy supply means generates a longitudinal magnetic field induction. In other words, the magnetic field lines of the magnetic fields generated by the first coil and the second coil extend in opposite directions and cancel each other out in the region where the magnetic fields overlap. In particular, when the first coil and the second coil are arranged in the same spatial configuration with respect to the transport direction and the width direction, the magnetic fields in the region where the magnetic fields overlap cancel each other out exactly.

[0131] Preferably, the induction heating device is designed to have a plurality of inductors, and at least one energy supply means is connected to the first and second coils of the plurality of inductors and is configured to supply electrical energy to the first and second coils of the plurality of inductors.

[0132] Preferably, the induction heating device is designed to have a plurality of energy supply means, each energy supply means connected to at least one first coil and at least one second coil of at least one inductor, and configured to supply electrical energy to the first coil and the second coil of the inductor.

[0133] Preferably, the induction heating device is designed to have open-loop and closed-loop control devices, which are designed for open-loop and / or closed-loop control of the supply of electrical energy to the first coil and / or the second coil.

[0134] The fundamental objective of the present invention is also achieved by a manufacturing line for producing and / or processing a metallic material having the features of claim 14 of the present invention.

[0135] The production line has at least one induction heating device according to the present invention as described above. Preferably, the production line has multiple induction heating devices according to the present invention as described above.

[0136] The fundamental objectives of the present invention are further achieved by the use of the induction heating apparatus and / or the manufacturing line according to the present invention.

[0137] In a series of tests to improve induction heating devices, various parameters of the induction heating device were varied in a multivariate test series. In particular, the penetration depth δ, pole distance, and edge distance were investigated in more detail. The advantages, details, and features of the present invention discovered during the tests are described in the further exemplary embodiments described below.

[0138] Surprisingly, contrary to the previous assumption that a higher penetration depth δ would also lead to higher electrical efficiency between the coil and the metallic material, it was found that the electrical efficiency between the coil and the metallic material decreased again with further increases in penetration depth δ.

[0139] The test series demonstrated that a specific maximum penetration depth or a penetration depth δ in a specific defined region was particularly advantageous. The test series yielded the results shown in Table 1.

[0140] [Table 1]

[0141] The penetration depth δ was adjusted in the test series according to the relationship in equation (1). For metallic materials, the temperature-dependent frequency of the alternating current flowing through the first and second coils can be approximately determined for a given penetration depth δ.

[0142] The heating uniformity and electrical efficiency along the thickness stretching of the metallic material were indirectly determined by thermographic images taken with a thermal imaging camera of the surface of the metallic material, particularly the first and / or second surfaces of the metallic material. The thermal energy generated in the metallic material, and therefore the temperature of the metallic material, is determined according to the law of current-heat (also known as "Joule's first law") and directly depends on the current flowing through the metallic material. Starting from the temperature measured on the surface of the metallic material, particularly the first and / or second surfaces of the metallic material, the temperature of the thickness stretching of the metallic material can be approximately calculated via the current density in different layers of the thickness stretching of the metallic material using the relationship described in equation (1). The electrical efficiency between the coil and the metallic material was then determined according to the relationship in equation (2). The power converted in the metallic material was determined from the thermal energy converted in the metallic material over a specified time period. From the power supplied to the first and second coils measured over the same time period, the electrical efficiency between the coil and the metallic material can finally be determined. The power loss in a coil can also be determined from the difference between the power supplied to the first and second coils and the power converted within the metal material.

[0143] Alternatively, the temperature distribution during thickness stretching can be directly determined by testing using thermocouples embedded in the metal material.

[0144] When a heating uniformity of 10 is specified along the thickness of the metal material for a given combination of parameters, the temperature deviation along the thickness of the metal material is less than 1 Kelvin per millimeter. For example, for a metal material with a thickness of 110 mm, the maximum difference between the highest and lowest temperatures along the thickness stretching of the metal material is 110 Kelvin.

[0145] Surprisingly, while the electrical efficiency between the coil and the metal material can be increased by reducing the edge distance, it was also shown that the heating uniformity along the width of the metal material decreases again as the edge distance decreases.

[0146] The test series demonstrated that the first and / or second edge distances were particularly advantageous within a specific defined range. The test series yielded the results shown in Table 2.

[0147] [Table 2]

[0148] In the test series of results summarized in Table 2, heating uniformity along the width stretching of the metallic material was directly determined by thermographic images using a thermal imaging camera of the surface of the metallic material, particularly the first and / or second surfaces of the metallic material. Electrical efficiency was determined in the same manner as in the test series of results shown in Table 1.

[0149] Surprisingly, it was also shown that as the pole distance increased, heating uniformity along the width of the metal material increased, but the electrical efficiency between the coil and the metal material decreased again.

[0150] The test series demonstrated that the first and / or second polar distances are particularly advantageous in certain defined regions. The test series yielded the results shown in Table 3.

[0151] [Table 3]

[0152] In the test series of results summarized in Table 3, heating uniformity along the width stretching of the metallic material was directly determined by thermographic images using a thermal imaging camera of the surface of the metallic material, particularly the first and / or second surfaces of the metallic material. Electrical efficiency was determined in the same manner as in the test series of results shown in Table 1.

[0153] Further advantages, details, and features of the present invention can be found in the embodiments described below. [Brief explanation of the drawing]

[0154] [Figure 1] An induction heating device according to the first embodiment is shown in a perspective view. [Figure 2] A cross-sectional view of the induction heating device according to the second embodiment is shown. [Figure 3] The induction heating device according to the second embodiment is shown in a plan view of the conveying surface. [Modes for carrying out the invention]

[0155] In the following description, the same reference numerals indicate the same component or feature. To avoid repetition, descriptions of components made with reference to one figure also apply to other figures. Furthermore, individual features described in relation to one embodiment may also be used separately in other embodiments.

[0156] Figure 1 is a perspective view of an induction heating device 1 for heating a metal material 40 being transported in a transport direction R1, according to a first embodiment. The induction heating device has an inductor 2 having a first coil 10 and a second coil 20. The first coil 10 and the second coil 20 are spaced apart from each other in the separation direction R2, defining at least a partial gap between them, so that the metal material 40 being transported in the transport direction R1 is transported through the gap space between the first coil 10 and the second coil 20. The first coil 10 has a winding formed by two first conductor profiles 11 connected to each other via a first connecting web 12. The second coil 20 has a winding formed by two second conductor profiles 21 connected to each other via a second connecting web 22. The first connecting web 12 and the second connecting web 22 are positioned at a distance from the first outer edge 41 of the metal material 40.

[0157] The first coil 10 has a first core 13, and the second coil has a second core 23. The first core 13 and the second core 23 each extend laterally R3 beyond the second outer edge 42 of the metal material 40.

[0158] The first coil 10 is positioned at a distance R2 in the direction of separation from the first surface 43 of the metal material 40, and the second coil 20 is positioned at a distance R2 in the direction of separation from the second surface 44 of the metal material 40, which is not shown in Figure 1.

[0159] Figure 2 shows a cross-sectional view of an induction heating device 1 for heating a metal material 40 being transported in the transport direction R1 according to a second embodiment. The induction heating device 1 has an inductor 2 having a first coil 10 and a second coil 20. The first coil 10 and the second coil 20 are spaced apart from each other in the separation direction R2, defining at least a partial gap between them. As a result, the metal material 40 being transported in the transport direction R1 is transported at least partially through the gap space between the first coil 10 and the second coil 20. The induction heating device 1 further has an energy supply means (not shown in Figure 1) electrically connected to the first coil 10 and the second coil 20 and configured to supply alternating current and / or alternating voltage to the first coil 10 and the second coil 20. Consequently, the penetration depth δ of the energized layer of the transported metal material 40 is 0.7 times or less the thickness extension t of the transported metal material 40.

[0160] The energy supply means 30 is configured to supply alternating current to the first coil 10 and the second coil 20, and the alternating currents of the first coil 10 and the second coil 20 have a phase shift of 180° relative to each other. In other words, the induction heating device 1 shown in Figure 2 generates a longitudinal magnetic field induction, and as a result, the current induced in the metal material 40 by the first coil 10 flows in the opposite direction to the current induced by the second coil 20.

[0161] The first coil 10 is located at a first distance h1 in the direction R2 away from the first surface 43 of the metal material 40 being conveyed, and the second coil 20 is located at a second distance h2 in the direction R2 away from the second surface 44 of the metal material 40 being conveyed. The first coil 10 and the second coil 20 define the gap d through which the metal material 40 is conveyed in the direction R2 away from each other.

[0162] The first coil 10 has at least one turn formed by at least two first conductor profiles 11 connected via a first connecting web 12 (not shown in Figure 1), and the second coil 20 has at least one turn formed by at least two second conductor profiles 21 connected via a second connecting web 22 (not shown in Figure 1).

[0163] The two first conductor profiles 11 of the first coil 10 are at a first pole distance s1 from each other, and the two second conductor profiles 21 of the second coil 20 are at a second pole distance s2 from each other.

[0164] The first coil 10 has two first cores 13, each of which is arranged such that when an alternating current flows through the first coil, the first cores 13 each form a magnetic path for the magnetic flux generated by the alternating current flowing through the first coil 10. The second coil 20 has two second cores 23, each of which is arranged such that when an alternating current flows through the second coil 20, the second cores 23 each form a magnetic path for the magnetic flux generated by the alternating current flowing through the second coil.

[0165] The first core 13 surrounds the first conductor profile 11 with three faces each. The faces of the first conductor profile 11 facing the first face 43 of the metal material 40 are not covered by the material of the first core 13. The second core 23 surrounds the second conductor profile 21 with three faces each. The faces of the second conductor profile 21 facing the second face 44 of the metal material 40 are not covered by the material of the second core 23.

[0166] Figure 3 shows an induction heating device 1 for heating a metal material 40 being conveyed in the conveying direction R1, according to the second embodiment, in a plan view of one conveying surface.

[0167] The energy supply means 30 is electrically connected to the first coil 10 and the second coil 20 (not shown in Figure 3).

[0168] The two first conductor profiles 11 of the first coil 10 are connected to each other by the first connecting web 12 to form a winding.

[0169] The first connecting web 12 is located at a first edge distance a from the first outer edge 41 of the metal material 40. 11 It is located there.

[0170] Each first core 13 extends laterally R3 along the first conductor profile 11 over a length range greater than the width extension b of the metal material 40. Each first core 13 starts from the first connecting web 12 and extends laterally R3, protruding beyond the metal material 40 in width extension, resulting in a first edge distance a between the second outer edge 42 of the metal material 40 and the extended end of the first core 13 in the lateral R3. 12 A formation is created. [Explanation of Symbols]

[0171] 1 Induction heating device 2 Inductors 10. The first coil 11 First conductor profile (of the first coil) 12 (First coil) First connection web 13 The first core (of the first coil) 20. The second coil 21 (Second conductor profile of the second coil) 22 (Second connection web of the second coil) 23 (The second core of the second coil) 30 Energy supply means 40 Metal materials 41 (The first outer edge of a metallic material) 42 (The second outer edge of the metallic material) 43 The first surface (of a metallic material) 44. The second surface (of a metallic material) R1 Conveying direction R2 Separation direction R3 Lateral d void H1 First distance h2 is the second distance a 11 First edge distance (from the first outer edge) a 12 (First edge distance from the second outer edge) s1 First polar distance s2 Second polar distance t (of metal materials) thickness stretching b. (Stretching of metallic materials)

Claims

1. An induction heating device (1) for heating a metal material (40) being transported in the transport direction (R1), wherein the induction heating device (1) - At least one inductor (2) having at least one first coil (10) and at least one second coil (20), - The first coil (10) and the second coil (20) are arranged with a gap between them in the separation direction (R2), defining at least a partial gap, thereby allowing the metal material (40) being transported in the transport direction (R1) to pass at least partially through the gap space between the first coil (10) and the second coil (20) via at least one inductor (2). - comprising at least one energy supply means (30) electrically connected to the first coil (10) and the second coil (20), - An induction heating device (1) characterized in that the energy supply means (30) is designed to supply alternating current and / or alternating voltage to the first coil (10) and the second coil (20) such that the penetration depth δ of the current-carrying layer of the conveyed metal material (40) is 0.7 times or less the thickness extension (t) of the conveyed metal material (40).

2. - The first coil (10) is positioned at a first distance (h) of 150 mm or less in the separation direction (R2) from the first surface (43) of the metal material (40) being conveyed. １ ) and / or, - The second coil (20) is positioned at a second distance (h) of 150 mm or less in the separation direction (R2) from the second surface (44) of the metal material (40) being conveyed. ２ The induction heating apparatus (1) described in claim 1.

3. - The first coil (10) has at least one turn formed by at least two first conductor profiles (11) connected via a first connecting web (12), - The first connecting web (12) of the first coil (10) is located at a first edge distance (a) from the first outer edge (41) of the conveyed metal material (40) that is no more than five times the elongation of the gap d between the first coil (10) and the second coil (20). １１ ) and / or, - The second coil (20) has at least one turn formed by at least two second conductor profiles (21) connected via a second connecting web (22), - The second connecting web (22) of the second coil (20) is located at a second edge distance (a) from the first outer edge (41) of the conveyed metal material (40) to a distance of five times or less the extension of the gap d between the first coil (10) and the second coil (20). ２１ An induction heating device (1) according to claim 1 or 2, located in ).

4. - The at least two first conductor profiles (11) of the first coil (10) are separated from each other by a first pole distance (s) of no more than four times the extension of the gap d. １ ) and / or, - The at least two second conductor profiles (21) of the second coil (20) are separated from each other by a second pole distance (s) of no more than four times the extension of the gap d. ２ An induction heating device (1) according to any one of claims 1 to 3.

5. The induction heating apparatus (1) according to any one of claims 1 to 4, wherein the energy supply means is suitable for supplying an alternating current and / or an alternating voltage frequency of 100 kHz or less to the first coil (10) and the second coil (20).

6. - The energy supply means is suitable for supplying at least 1,000 kW of power to the first coil (10) and / or the second coil (20) for a period of at least one minute, and / or - The induction heating apparatus (1) according to any one of claims 1 to 5, wherein the first coil (10) and / or the second coil (20) are each suitable for absorbing at least 1,000 kW of power over a period of at least 1 minute.

7. The induction heating apparatus (1) according to any one of claims 1 to 6, wherein the induction heating apparatus has a displacement device suitable for displacing the at least one first coil (10) and / or the at least one second coil (20) of the inductor (2) in the separation direction (R2) and / or the lateral direction (R3) and / or the transport direction (R1) of the metal material (40), in particular for displacing the at least one first coil (10) and / or the at least one second coil (20) of the inductor (2) to a working position.

8. - The first coil (10) has at least one first core (13), the first core (13) is arranged such that when an alternating current flows through the first coil (10), the first core (13) forms a magnetic path for the magnetic flux generated by the alternating current flowing through the first coil (10), and / or - The induction heating apparatus (1) according to any one of claims 1 to 7, wherein the second coil (20) has at least one second core (23), the second core (23) is arranged such that when an alternating current flows through the second coil (20), the second core (23) forms a magnetic path for the magnetic flux generated by the alternating current flowing through the second coil (20).

9. The induction heating device (1) is - At least one first capacitor device, wherein the first capacitor device is connected to the at least one first coil (10) to form a first partial resonant circuit, and / or one of the first capacitor devices is connected to the at least one second coil (20) to form a second partial resonant circuit, and / or - An induction heating device (1) according to any one of claims 1 to 8, comprising at least one second capacitor device, the second capacitor device being connected to the at least one second coil (20) to form a second partial resonant circuit.

10. - The induction heating device (1) has at least one matching transformer, - The induction heating device (1) according to any one of claims 1 to 9, wherein the secondary side of the matching transformer is electrically connected at least indirectly to the at least one first coil (10) and / or the at least one second coil (20).

11. - The energy supply means is designed to supply alternating current to the at least one first coil (10) and the at least one second coil (20), and the alternating current of the at least one first coil (10) and the alternating current of the at least one second coil (20) may have the same phase or phase shift relative to each other. - The induction heating apparatus (1) according to any one of claims 1 to 10, wherein the energy supply means is designed to supply an alternating voltage to the at least one first coil (10) and the at least one second coil (20), and the alternating voltage of the at least one first coil (10) and the alternating voltage of the at least one second coil (20) may have the same phase or phase shift with respect to each other.

12. - The induction heating device (1) has a plurality of inductors (2), - The induction heating apparatus (1) according to any one of claims 1 to 11, wherein the at least one energy supply means is connected to the first coil (10) and the second coil (20) of the plurality of inductors and is configured to supply electrical energy to the first coil (10) and the second coil (20) of the plurality of inductors (2).

13. The induction heating apparatus (1) according to any one of claims 1 to 12, wherein the induction heating apparatus (1) has an open-loop and closed-loop control device, the open-loop and closed-loop control device is designed for open-loop and / or closed-loop control of the supply of electrical energy to the first coil (10) and / or the second coil (20).

14. A manufacturing line for manufacturing and / or processing a metal material (40), comprising an induction heating device (1) according to any one of claims 1 to 13.

15. Use of the induction heating apparatus (1) according to any one of claims 1 to 13 and / or the manufacturing line according to claim 14.

Images