Transverse type induction heating device

Abstract

In one slot (1121a, 1121b, 1221a, 1221b), first copper pipes (1111a to 1111f, 1211a to 1211f) and a second copper pipe (1111g, 1111h, 1211g, 1211h) are disposed. At each position (each y-coordinate) in a heated length direction in the one slot, the first copper pipe is located closest to a conductor plate M. In the one slot, the second copper pipe is located closer to the conductor plate M than at least one first copper pipe. In the one slot, there is at least one second copper pipe electrically connected in series to the first copper pipe.

Description

[Technical Field]

[0001] The present invention relates to a transverse induction heating device. This application claims priority to Japanese Patent Application No. 2022-121529, filed on July 29, 2022, the contents of which are incorporated herein by reference in their entirety. [Background technology]

[0002] An induction heating device is an apparatus for heating a conductive plate. The induction heating device has a coil. An alternating magnetic field (AC magnetic field) is generated from the coil of the induction heating device. The alternating magnetic field induces eddy currents in the conductive plate. The conductive plate is heated by Joule heat based on the eddy currents. One such induction heating device is a transverse type induction heating device. The transverse type induction heating device induces eddy currents in the conductive plate by causing an alternating magnetic field to cross the conductive plate approximately perpendicularly (preferably perpendicularly).

[0003] Patent Document 1 describes a technology for a transverse type induction heating device. Patent Document 1 discloses a transverse induction heating device in which the widths of the upper and lower coils are equal to or greater than the distance between them, where the coil width is the length of the coil in the direction of transport of the conductor plate to be heated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-27470 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology described in Patent Document 1 describes that when increasing the number of turns (windings) of the coil to increase the heating capacity of the induction heating device, the coil is wound in the direction of transport of the conductive plate to be heated. Therefore, with the technology described in Patent Document 1, when increasing the heating capacity of the induction heating device, it is necessary to increase the length of the induction heating device in the direction of transport of the conductive plate to be heated (the width of the coil, the width of the slot). Therefore, with the technology described in Patent Document 1, the length of the induction heating device in the direction of transport of the conductive plate to be heated increases in proportion to the increase in the heat capacity of the conductive plate to be heated (it is assumed that the heating capacity is proportional to the square of the AC current flowing through the coil).

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a transverse type induction heating device that can ensure the heating capacity necessary to heat the conductor plate while preventing the conductor plate from becoming longer in the conveying direction. [Means for solving the problem]

[0007] The transverse type induction heating device of the present invention has an upper inductor and a lower inductor arranged to face each other with a conductor plate sandwiched therebetween, and induction heats the conductor plate by crossing an alternating magnetic field across the plate surface of the conductor plate, wherein each of the upper inductor and the lower inductor has a coil and a core, the number of turns of the coil is two or more, the core has a slot which is a space in which the coil is placed, the coil has a plurality of conductor parts electrically connected to each other, the conductor parts have at least one first conductor part and at least one second conductor part, and the first conductor part is the second conductor is the conductor located closest to the conductor plate at each position in the heating longitudinal direction in one of the slots, the second conductor is the conductor located farther from the conductor plate than at least one of the first conductors in one of the slots, in one of the slots at least a portion of the position in the heating longitudinal direction of at least one of the first conductors overlaps with at least a portion of the position in the heating longitudinal direction of at least one of the second conductors, the heating longitudinal direction is parallel to the conveying direction of the conductor plate, and one of the slots has at least one second conductor electrically connected in series to the first conductor. The conductor portion is not disposed in a region of the slot in which the conductor portion is disposed, where the magnetic flux density is highest when the core is excited by an AC current flowing through the coil. . [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a first example of a transverse type induction heating device. [Figure 2] FIG. 2 is a diagram showing a second example of a transverse type induction heating device. [Figure 3] FIG. 3 is a diagram showing a first example of the coil configuration. [Figure 4] FIG. 4 is a diagram illustrating an example of a core configuration. [Figure 5] FIG. 5 is a diagram showing a second example of the coil configuration. [Figure 6] FIG. 6 is a diagram illustrating an example of the penetration depth. [Figure 7]FIG. 7 is a diagram showing a third example of a transverse type induction heating device. [Figure 8] FIG. 8 is a diagram showing a fourth example of a transverse type induction heating device. [Figure 9] FIG. 9 is a diagram showing a fifth example of a transverse type induction heating device. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the term "sameness" in terms of length, position, size, spacing, etc., includes not only cases where the objects are exactly the same, but also cases where they are different within the scope of the invention (for example, differences within the tolerances established at the time of design). In addition, for the convenience of explanation and notation, in each figure, only parts necessary for explanation are shown, simplified as necessary. In each figure, the x-y-z coordinates indicate the orientation relationship in each figure. A symbol with a cross mark (×) inside a white circle (○) indicates that the direction from the front to the back of the page is the positive axis. In this embodiment, the x-y plane is a horizontal plane, and the z-axis direction is the height direction.

[0010] FIG. 1 is a diagram illustrating a first example of a transverse-type induction heating device. FIG. 2 is a diagram illustrating a second example of a transverse-type induction heating device. In this embodiment, the conveying direction of the conductor plate M is the positive y-axis direction, the width direction of the conductor plate M is the x-axis direction, and the thickness direction of the conductor plate M is the z-axis direction. Here, the direction parallel to the conveying direction of the conductor plate M (the positive y-axis direction) (i.e., the y-axis direction) is referred to as the heating length direction. The heating length direction corresponds to the longitudinal direction of the conductor plate M. FIGS. 1 and 2 show a cross section (y-z cross section) of the transverse-type induction heating device taken perpendicular to the width direction (x-axis direction) of the conductor plate M so as to pass through the center of gravity of the induction heating device 1000. FIG. 1 shows an example of a transverse-type induction heating device 1000 in which the number of turns (number of windings) of each coil is even. FIG. 2 shows an example of a transverse-type induction heating device 2000 in which the number of turns (number of windings) of each coil is odd. The transverse type induction heating devices 1000 and 2000 shown in FIGS. 1 and 2 differ only in the number of turns (windings) of the coil.

[0011] The transverse type induction heating devices 1000 and 2000 induce heating of the conductor plate M by applying an alternating magnetic field substantially perpendicularly (preferably perpendicularly) to the surface of the conductor plate M during transportation. The conductor plate M is, for example, a metal plate such as a steel plate. In the following description, the transverse type induction heating device will be abbreviated as "induction heating device" as necessary. An example of the configuration of the induction heating devices 1000 and 2000 will be described below. The dimensions (D1, D2, K1, K2, etc.) of the induction heating devices 1000 and 2000 will be described later in the section "Design Method."

[0012] (Induction heating device 1000) First, the configuration of the induction heating device 1000 shown in FIG. 1 will be described. The induction heating device 1000 includes an upper inductor 1100 and a lower inductor 1200. The upper inductor 1100 and the lower inductor 1200 are disposed with a gap in the thickness direction (z-axis direction) of the conductor plate M so as to face each other with the conductor plate M sandwiched therebetween. In this manner, the thickness direction (z-axis direction) of the conductor plate M corresponds to the direction in which the upper inductor 1100 and the lower inductor 1200 face each other. The induction heating device 1000 shown in FIG. 1 illustrates a case in which the upper inductor 1100 and the lower inductor 1200 are in a plane-symmetric relationship with respect to an imaginary plane SL. The imaginary plane SL passes through the center of the conductor plate M in the thickness direction (z-axis direction) and is parallel to the width direction (x-axis direction) and longitudinal direction (y-axis direction) of the conductor plate M. Note that the imaginary plane SL is not an actual plane.

[0013] The upper inductor 1100 and the lower inductor 1200 have coils 1110 and 1210 and cores 1120 and 1220, respectively. The coils 1110 and 1210 are arranged such that the center lines of the coils 1110 and 1210 are approximately perpendicular (preferably perpendicular) to the plate surface of the conductive plate M. The number of turns of the coils 1110 and 1210 is N (N is an integer equal to or greater than 2). As described above, the number of turns of the coils 1110 and 1210 of the induction heating device 1000 shown in FIG. 1 is an even number. FIG. 1 illustrates a case where the number of turns N of the coils 1110 and 1210 is 4. In an example described later with reference to FIG. 3, the coils 1110 and 1210 are electrically connected in series. In this case, the total number of turns of the coils 1110 and 1210 in the induction heating device 1000 is 8 (= 2 × 4). On the other hand, if the coils 1110 and 1210 are electrically connected in parallel, the total number of turns of the coils 1110 and 1210 in the induction heating device 1000 is 4. Note that "electrically connected in series" has the same meaning as "series connection" commonly used in the field of electric circuits. Also, "electrically connected in parallel" has the same meaning as "parallel connection" commonly used in the field of electric circuits. In the following description, "electrically connected in series" will be simply referred to as "series connection" as necessary. Also, "electrically connected in parallel" will be simply referred to as "parallel connection" as necessary.

[0014] FIG. 3 is a diagram showing an example of the configuration of the coils 1110 and 1210. As shown in FIG. In Fig. 3, coils 1110 and 1210 include copper pipes 1111a-1111h and 1211a-1211h and copper bus bars 1112a-1112h and 1212a-1212h, respectively. Fig. 3 illustrates a case where induction heating device 1000 includes copper bus bar 1130. Fig. 3 also illustrates a case where coils 1110 and 1210 are connected in series by copper bus bar 1130. In Fig. 3, arrows shown inside copper pipes 1111a-1111h and 1211a-1211h, copper bus bars 1112a-1112h and 1212a-1212h, and copper bus bar 1130 indicate the direction of AC current flowing through each part at the same time.

[0015] First, we will explain an example of the electrical connection relationship between the copper pipes 1111a to 1111h, 1211a to 1211h, the copper bus bars 1112a to 1112h, 1212a to 1212h, and the copper bus bar 1130. It is assumed that electrical insulation is ensured among the copper pipes 1111a to 1111h, 1211a to 1211h, the copper bus bars 1112a to 1112h, 1212a to 1212h, and the copper bus bar 1130, except for the portions connected to other members (this also applies to FIG. 5, which will be described later).

[0016] In FIG. 3, one end of copper bus bar 1112a is electrically connected to one end 3001 of AC power supply 3000. The other end of copper bus bar 1112a is electrically connected to one end side (negative side of the x-axis) of copper pipe 1111a. One end of copper bus bar 1112b is electrically connected to the other end side (positive side of the x-axis) of copper pipe 1111a. The other end of copper bus bar 1112b is electrically connected to one end side (positive side of the x-axis) of copper pipe 1111f. One end of copper bus bar 1112c is electrically connected to the other end side (negative side of the x-axis) of copper pipe 1111f. As described above, the first turn (same turn) of coil 1110 is formed using copper bus bar 1112a, copper pipe 1111a, copper bus bar 1112b, and copper pipe 1111f. The copper bus bar 1112c serves to electrically connect the first turn and the second turn of the coil 1110.

[0017] The other end of the copper bus bar 1112c is electrically connected to one end (negative side of the x-axis) of the copper pipe 1111g. One end of the copper bus bar 1112d is electrically connected to the other end (positive side of the x-axis) of the copper pipe 1111g. The other end of the copper bus bar 1112d is electrically connected to one end (positive side of the x-axis) of the copper pipe 1111h. One end of the copper bus bar 1112e is electrically connected to the other end (negative side of the x-axis) of the copper pipe 1111h. As described above, the second turn (same turn) of the coil 1110 is formed using the copper pipe 1111g, copper bus bar 1112d, and copper pipe 1111h. The copper bus bar 1112e electrically connects the second and third turns of the coil 1110.

[0018] The other end of the copper bus bar 1112e is electrically connected to one end (negative side of the x-axis) of the copper pipe 1111b. One end of the copper bus bar 1112f is electrically connected to the other end (positive side of the x-axis) of the copper pipe 1111b. The other end of the copper bus bar 1112f is electrically connected to one end (positive side of the x-axis) of the copper pipe 1111e. One end of the copper bus bar 1112g is electrically connected to the other end (negative side of the x-axis) of the copper pipe 1111e. As described above, the third turn (same turn) of the coil 1110 is formed using the copper pipe 1111b, the copper bus bar 1112f, and the copper pipe 1111e. The copper bus bar 1112g electrically connects the third and fourth turns of the coil 1110.

[0019] The other end of the copper bus bar 1112g is electrically connected to one end (negative side of the x-axis) of the copper pipe 1111c. One end of the copper bus bar 1112h is electrically connected to the other end (positive side of the x-axis) of the copper pipe 1111c. The other end of the copper bus bar 1112h is electrically connected to one end (positive side of the x-axis) of the copper pipe 1111d. One end of the copper bus bar 1130 is electrically connected to the other end (negative side of the x-axis) of the copper pipe 1111d. As described above, the fourth turn (same turn) of the coil 1110 is formed using the copper pipe 1111c, the copper bus bar 1112h, and the copper pipe 1111d. As described above, copper bus bar 1130 is used to connect coils 1110 and 1210 (the fourth turn of coil 1110 and the first turn of coil 1210) in series. The other end of copper bus bar 11130 is electrically connected to one end side (the negative side of the x-axis) of copper pipe 1211a of coil 1210.

[0020] In the coil 1110 of the upper inductor 1100, the winding start portion (copper bus bar 1112a) of the first turn is electrically connected to one end 3001 of the AC power supply 3000. In contrast, in the coil 1210 of the lower inductor 1200, the winding start portion (copper pipe 1211a) of the first turn is electrically connected to the copper bus bar 1130. have In the coil 1110, the winding end portion of the fourth turn (copper pipe 1111d) is electrically connected to the copper bus bar 1130. In contrast, in the coil 1210 of the lower inductor 1200, the winding end portion of the fourth turn (copper bus bar 1212h) is electrically connected to the other end 3002 of the AC power supply 3000.

[0021] Except for these points, the electrical connection relationship between the copper pipes 1211a-1211h and the copper bus bars 1212a-1212h of the coil 1210 of the lower inductor 1200 is similar to the electrical connection relationship between the copper pipes 1111a-1111h and the copper bus bars 1112a-1112h of the coil 1110 of the upper inductor 1100. Therefore, in describing the coil 1210 of the lower inductor 1200, a description will be given of the copper pipes 1211a-1211h and the copper bus bars 1212a-1212h used to form each turn, and a description of the specific connection relationship between the copper pipes 1211a-1211h and the copper bus bars 1212a-1212h used to form the first to fourth turns will be omitted.

[0022] First, copper pipe 1211a, copper bus bar 1212a, and copper pipe 1211f form the first turn (same turn) of coil 1210. Copper bus bar 1212b is used to electrically connect the first turn and second turn of coil 1210.

[0023] Copper pipe 1211g, copper bus bar 1212c, and copper pipe 1211h form the second turn (same turn) of coil 1210. Copper bus bar 1212d is used to electrically connect the second turn and third turn of coil 1210.

[0024] Copper pipe 1211b, copper bus bar 1212e, and copper pipe 1211e form the third turn (same turn) of coil 1210. Copper bus bar 1212f is used to electrically connect the third turn and fourth turn of coil 1210.

[0025] Furthermore, the fourth turn (same turn) of the coil 1210 is formed using the copper pipe 1211c, the copper bus bar 1212g, and the copper pipe 1211d. One end of the copper bus bar 1212h is electrically connected to the other end (negative side of the x-axis) of the copper pipe 1211d. The other end of the copper bus bar 1212h is electrically connected to the other end 3002 of the AC power supply 3000.

[0026] 1 and 3 show an example in which the copper pipes 1111a-1111h and 1211a-1211h have the same size and shape. The copper pipes 1111a-1111h and 1211a-1211h have a hollow rectangular parallelepiped shape. A cooling medium (e.g., cooling water) is supplied to the hollow parts of the copper pipes 1111a-1111h and 1211a-1211h.

[0027] Note that Figure 3 illustrates an example in which the conductor plate M is inductively heated by connecting the coils 1110 and 1210 in series, thereby causing the alternating current flowing through the coils 1110 and 1210 to cause the magnetic fluxes generated from the coils 1110 and 1210 to have approximately the same (preferably the same) direction at the same time, and by causing an alternating magnetic field to intersect approximately perpendicular (preferably perpendicular) to the plate surface of the conductor plate M.

[0028] However, the coils 1110 and 1210 may be connected in parallel as long as the alternating currents flowing through the coils 1110 and 1210 cause the magnetic fluxes generated from the coils 1110 and 1210 to have substantially the same (preferably the same) direction at the same time, and the alternating magnetic fields are caused to intersect substantially perpendicular (preferably perpendicular) to the plate surface of the conductive plate M. Also, the coils 1110 and 1210 do not need to be electrically connected. In this case, the alternating currents flowing through the coils 1110 and 1210 are alternating currents supplied from separate alternating current power sources.

[0029] When the coils 1110 and 1210 are connected in parallel, for example, the copper bus bar 1130 is not necessary. Instead, one end (negative side of the x-axis) of the copper pipe 1211a of the coil 1210 is connected to one end 3001 of the AC power supply 3000 via the copper bus bar 1112a or the like. The other end (negative side of the x-axis) of the copper pipe 1111d of the coil 1110 is connected to the other end 3002 of the AC power supply 3000. The other end (negative side of the x-axis) of the copper pipe 1111d of the coil 1110 may be connected to the other end 3002 of the AC power supply 3000 via the copper bus bar 1212h or the like. When the coils 1110 and 1210 are connected in parallel, the total number of turns of the coils 1110 and 1210 in the induction heating device 1000 is four.

[0030] The shape of the conductor portion constituting the coil is not limited to a hollow rectangular parallelepiped. For example, it may be a hollow cylindrical shape. Furthermore, the conductor portion constituting the coil does not have to have a hollow region. In this case where the conductor portion constituting the coil does not have a hollow region, for example, a pipe serving as a path through which a cooling medium (e.g., cooling water) flows may be arranged so as to surround the conductor portion constituting the coil.

[0031] FIG. 4 is a diagram illustrating an example of the configuration of the cores 1120 and 1220. In this embodiment, the cores 1120 and 1220 are illustrated as so-called E-shaped cores. The cores 1120 and 1220 are made of a soft magnetic material. The cores 1120 and 1220 have slots 1121a-1121b and 1221a-1221b, which are spaces in which the coils 1110 and 1210 are disposed, respectively. The example illustrated in FIGS. 1 and 3 illustrates a case in which copper pipes 1111a-1111c and 1111g are disposed in the slot 1121a of the core 1120. The example illustrated in FIGS. 1 and 3 also illustrates a case in which copper pipes 1111d-1111f and 1111h are disposed in the slot 1121b of the core 1120. 1 and 3 illustrate a case where copper pipes 1211a to 1211c and 1211g are arranged in slot 1221a of core 1220. Also, in the example illustrated in Figures 1 and 3, a case where copper pipes 1211d to 1211f and 1211h are arranged in slot 1221b of core 1220 is illustrated.

[0032] As described above, when the coils 1110 and 1210 are installed in the cores 1120 and 1220, the copper pipes 1111a to 1111h and 1211a to 1211h are inserted into the slots 1121a to 1121h of the cores 1120 and 1220, respectively. 1121b , 1221a to 1221b. Therefore, the copper bus bars 1112a to 1112h and 1212a to 1212h are attached to the copper pipes 1111a to 1111h and 1211a to 1211h, respectively, avoiding the areas of the copper pipes 1111a to 1111h and 1211a to 1211h that are attached to the cores 1120 and 1220. For example, in FIG. 3, the areas of the copper pipes 1111a to 1111h and 1211a to 1211h where the copper bus bars 1112a to 1112h and 1212a to 1212h are attached are respectively located within the slots 1121a to 1121b , and are arranged outside 1221a to 1221b.

[0033] The cores 1120 and 1220 each have a first leg 1122 and 1222, a second leg 1123 and 1223, a third leg 1124 and 1224, and a body 1125 and 1225, respectively.

[0034] 4 shows, as imaginary lines, a boundary line 1126a between the first leg 1122 and the body 1125, a boundary line 1126b between the second leg 1123 and the body 1125, and a boundary line 1126c between the third leg 1124 and the body 1125 for the core 1120. Similarly, as imaginary lines, a boundary line 1226a between the first leg 1222 and the body 1225, a boundary line 1226b between the second leg 1223 and the body 1225, and a boundary line 1226c between the third leg 1224 and the body 1225 for the core 1220. Note that these imaginary lines are not actual lines.

[0035] The first legs 1122, 1222 are disposed at the center of the cores 1120, 1220 in the heating longitudinal direction (y-axis direction). The second legs 1123, 1223 and the third legs 1124, 1224 are disposed on both sides of the first legs 1122, 1222 in the heating longitudinal direction (y-axis direction) with a gap between them. Specifically, FIG. 4 illustrates a case in which the second legs 1123, 1223 are disposed on the negative side of the y-axis with a gap between them. Similarly, FIG. 4 illustrates a case in which the third legs 1124, 1224 are disposed on the positive side of the y-axis with a gap between them.

[0036] Fig. 4 illustrates an example in which the first legs 1122, 1222, the second legs 1123, 1223, the third legs 1124, 1224, and the trunks 1125, 1225 have a rectangular parallelepiped shape. Fig. 4 also illustrates an example in which the first legs 1122, 1222, the second legs 1123, 1223, the third legs 1124, 1224, and the trunks 1125, 1225 have the same length in the width direction (x-axis direction) of the conductive plate M. Fig. 4 also illustrates an example in which the first legs 1122, 1222, the second legs 1123, 1223, and the third legs 1124, 1224 have the same length in the plate thickness direction (z-axis direction) of the conductive plate M.

[0037] FIG. 4 also illustrates an example in which the body 1125 is disposed closer to the rear side than the first leg 1122, the second leg 1123, and the third leg 1124. The rear side is the side opposite to the side where the conductive plate M is present (i.e., the side where the conductive plate M is not present). Specifically, FIG. 4 illustrates an example in which the base end faces (end faces opposite to the conductive plate M side) of the first leg 1122, the second leg 1123, and the third leg 1124 are connected seamlessly to the body 1125. The base end faces of the first leg 1122, the second leg 1123, and the third leg 1124 are end faces on the positive side of the z-axis. Therefore, the first leg 1122, the second leg 1123, and the third leg 1124 are magnetically connected to the body 1125. The first leg 1122, the second leg 1123, and the third leg 1124 being magnetically connected to the body 1125 means that the same main magnetic flux flows through the first leg 1122, the second leg 1123, and the third leg 1124, and the body 1125. The main magnetic flux is a magnetic flux that contributes to heating the conductive plate M. For example, the main magnetic flux flows in a closed circuit (magnetic path) that passes through the core 1120 of the upper inductor 1100, the conductive plate M, and the core 1220 of the lower inductor 1200.

[0038] FIG. 4 also illustrates an example in which the tip surfaces of the first leg 1122, the second leg 1123, and the third leg 1124 face the plate surface of the conductive plate M (the surface on the positive side of the z-axis) with a gap therebetween.

[0039] Similarly, for core 1220, a case where trunk 1225 is disposed on the rear side of first leg 1222, second leg 1223, and third leg 1224 is illustrated. Specifically, FIG. 4 illustrates a case where the base end surfaces of first leg 1222, second leg 1223, and third leg 1224 are connected to trunk 1225 without a break. Note that the base end surfaces of first leg 1222, second leg 1223, and third leg 1224 are end surfaces on the negative side of the z-axis. Therefore, first leg 1222, second leg 1223, and third leg 1224 are magnetically connected to trunk 1225.

[0040] FIG. 4 also illustrates a case where the tip surfaces of the first leg 1222, the second leg 1223, and the third leg 1224 face the plate surface of the conductive plate M (the surface on the negative side of the z-axis) with a gap therebetween. 4 illustrates an example in which the shape and size of the core 1220 are the same as those of the core 1120. In FIG.

[0041] For convenience of explanation, the cores 1120 and 1220 have been described as being divided into first legs 1122 and 1222, second legs 1123 and 1223, third legs 1124 and 1224, and trunks 1125 and 1225. However, the first legs 1122 and 1222, second legs 1123 and 1223, third legs 1124 and 1224, and trunks 1125 and 1225 are all integral with one another. Therefore, there are no boundaries between the first legs 1122 and 1222, second legs 1123 and 1223, third legs 1124 and 1224, and trunks 1125 and 1225 (as mentioned above, the two-dot chain lines shown in FIG. 4 do not actually exist). However, these may be manufactured as separate parts and then combined to form a single core. For example, at least two portions of first leg 1122, second leg 1123, third leg 1124, and body 1125 may be spaced apart from one another, provided that the at least two portions are configured and arranged such that the same main magnetic flux flows through the at least two portions. Similarly, at least two portions of first leg 1222, second leg 1223, third leg 1224, and body 1225 may be spaced apart from one another, provided that the at least two portions are configured and arranged such that the same main magnetic flux flows through the at least two portions.

[0042] Here, in order to increase the heating capacity of the induction heating device in the heating length direction (y-axis direction), it is necessary to increase the number of turns of the coil, as long as the current density of the conductor portion constituting the coil does not exceed the current density allowed for that conductor portion. In such a case, if coils are arranged only in the heating length direction (y-axis direction) of the induction heating device, the length of the induction heating device in the heating length direction will be long. On the other hand, the induction heating device induction heats the conductor plate M being transported in the heating length direction (y-axis direction). Therefore, if the length of the induction heating device in the heating length direction (y-axis direction) is long, there is a risk that the installation space for other equipment in the heating length direction (y-axis direction) will be narrowed, for example.

[0043] Therefore, the present inventors have found that, in order to configure an induction heating device that has the heating capacity necessary to heat the conductor plate M while suppressing an increase in length in the heating longitudinal direction (y-axis direction), it is preferable to configure coils 1110, 1210, for example, as shown in Fig. 1. An example of the configuration of coils 1110, 1210 for achieving this will be described below.

[0044] First, the coils 1110 and 1210 have a plurality of copper pipes 1111a-1111h and 1211a-1211h electrically connected to each other. In the example shown in FIGS. 1 and 3, the copper pipes 1111a-1111h and 1211a-1211h are an example of a conductor portion. Note that the conductor portion may be made of a conductor other than copper. Also, the conductor portion does not have to be a pipe.

[0045] At least two copper pipes out of the copper pipes 1111a to 1111h and 1211a to 1211h are placed in one slot each, 1121a, 1121b, 1221a, and 1221b.

[0046] At least one copper pipe 1111a to 1111f, 1211a to 1211f that falls under the following (A) is arranged in each slot 1121a, 1121b, 1221a, 1221b. In the following description, the copper pipe that falls under (A) will be referred to as a first copper pipe as necessary.

[0047] (A) First copper pipes 1111a to 1111c, 1111d to 1111f, 1211a to 1211c, 1211d to 1211f are copper pipes arranged at the positions closest to the conductive plate M at each position (each y coordinate) in the heating longitudinal direction (y-axis direction) in one slot 1121a, 1121b, 1221a, 1221b.

[0048] At each position (each y coordinate) in the heating longitudinal direction (y-axis direction) within one slot 1121a, 1121b, 1221a, 1221b, when multiple copper pipes (e.g., copper pipes 1111b, 1111g) are lined up in the thickness direction (z-axis direction) of the conductive plate M, the copper pipe (e.g., copper pipe 1111b) among the multiple copper pipes that is located closest to the conductive plate M is the first copper pipe.

[0049] On the other hand, if there is only one copper pipe in one slot 1121a, 1121b, 1221a, 1221b at each position (each y coordinate) in the heating longitudinal direction (y-axis direction) within that slot, that copper pipe (for example, copper pipe 1111a, 1111c) is the first copper pipe. 1 and 3 show an example in which the copper pipes 1111a to 1111f and 1211a to 1211f are first copper pipes.

[0050] Furthermore, at least one conductor portion is arranged in each slot 1121a, 1121b, 1221a, 1221b at a position farther from the conductor plate M than at least one of the first copper pipes 1111b, 1111e, 1211b, 1211e among the first copper pipes 1111a-1111f, 1211a-1211f. In the following description, such a copper pipe will be referred to as a second copper pipe as necessary. Figures 1 and 3 illustrate the case where the copper pipes 1111g-1111h and 1211g-1211h are second copper pipes.

[0051] In addition, in each slot 1121a, 1121b, 1221a, 1221b, at least a portion of the position (y coordinate) in the heating longitudinal direction (y axis direction) of at least one first copper pipe 1111b, 1111e, 1211b, 1211e overlaps with at least a portion of the position in the heating longitudinal direction of at least one second copper pipe 1111g, 1111h, 1211g, 1211h. Figure 1 illustrates a case where the position in the heating longitudinal direction of the first copper pipe 1111b, 1111e, 1211b, 1211e overlaps with the position in the heating longitudinal direction of the second copper pipe 1111g, 1111h, 1211g, 1211h at all positions (y coordinate) in the heating longitudinal direction (y axis direction).

[0052] 1 and 3, the first copper pipes 1111a to 1111f and 1211a to 1211f are an example of the first conductor portion, and the second copper pipes 1111g to 1111h and 1211g to 1211h are an example of the second conductor portion.

[0053] In each slot 1121a, 1121b, 1221a, 1221b, the first copper pipes 1111a to 1111f, 1211a to 1211f and the second copper pipes 1111g to 1111h, 1211g to 1211h respectively form different turns in the coils 1110, 1210. Different turns in the coils means that the turns do not make the same circuit around the coil.

[0054] For example, as described above, the first copper pipes 1111b and 1111e are the third turn of the coil 1110, and the second copper pipes 1111g and 1111h are the second turn of the coil 1110. Therefore, the first copper pipes 1111b and 1111e and the second copper pipes 1111g and 1111h each constitute a different turn of the coil 1110. In this case, the first copper pipes 1111b and 1111e and the second copper pipes 1111g and 1111h are connected in series.

[0055] Similarly, the first copper pipes 1211b and 1211e are the third turn of the coil 1210, and the second copper pipes 1211g and 1211h are the second turn of the coil 1210. Therefore, the first copper pipes 1211b and 1211e and the second copper pipes 1211g and 1211h each constitute a different turn of the coil 1210. In this case, the first copper pipes 1211b and 1211e and the second copper pipes 1211g and 1211h are connected in series.

[0056] In this way, the length in the heating longitudinal direction (y-axis direction) can be prevented from increasing compared to when copper pipes are arranged only in the heating longitudinal direction (y-axis direction), and the number of turns N of the coils 1110, 1210 can be increased as long as the current density of the copper pipes 1111a-1111h, 1211a-1211h constituting the coils 1110, 1210 does not exceed the current density allowed for the copper pipes. Thus, the induction heating device 1000 can be configured to have the heating capacity required to heat the conductor plate M while preventing the length of the induction heating device 1000 in the heating longitudinal direction (y-axis direction) from increasing.

[0057] 1 and 3, it is also preferable that the first copper pipes 1111a-1111f, 1211a-1211f have different turns in each slot 1121a, 1121b, 1221a, 1221b. This is because it is possible to increase the number of turns N of the coils 1110, 1210 while preventing the length of the induction heating device 1000 in the heating length direction (y-axis direction) from increasing.

[0058] Furthermore, when configuring induction heating device 1000 in this manner, it is preferable to arrange multiple copper pipes 1111a-1111c, 1111d-1111f, 1211a-1211c, 1211d-1211f in the heating length direction (y-axis direction), as this allows the number of turns of coils 1110 and 1210 to be increased.

[0059] Furthermore, if the coil 1110 is located in an area of ​​excessive magnetic flux density, the AC current flowing through the coils 1110 and 1210 is likely to be attracted to the surfaces of the coils 1110 and 1210 (copper pipes). Therefore, the current density of the AC current flowing through the coils 1110 and 1210 (copper pipes) is likely to become excessive. In this case, the copper pipes are locally overheated. This may result in a deterioration in the quality of the coils 1110 and 1210. For example, the copper pipes may melt. Therefore, it is preferable to avoid placing the copper pipes 1111a-1111h and 1211a-1211h in the area of ​​the highest magnetic flux density within a single slot 1121a, 1121b, 1221a, and 1221b when the cores 1120 and 1220 are excited by the AC current flowing through the coils 1110 and 1210.

[0060] Based on the results of electromagnetic field analysis of an induction heating device, the inventors have found that when cores 1120 and 1220 are so-called E-shaped cores as shown in Figures 1 and 4, the magnetic flux density is high in the high magnetic flux density region HB shown in Figure 1, and that the region with the highest magnetic flux density within one slot 1121a, 1121b, 1221a, or 1221b is included in the high magnetic flux density region HB. Note that in Figure 1, the high magnetic flux density region HB is simplified for ease of explanation and notation (this also applies to Figure 2). The high magnetic flux density region HB includes a region near the boundary between slots 1121a, 1121b, 1221a, or 1221b of cores 1120 and 1220 and first legs 1122 and 1222 of cores 1120 and 1220 on the tip side (the side closer to conductor plate M). Therefore, it is preferable that the copper pipes 1111a-1111h, 1211a-1211h are not placed in the high magnetic flux density region HB. Here, the high magnetic flux density region HB is preferably an insulating region. In this embodiment, a case where the high magnetic flux density region HB is space (air) is exemplified. However, an object (preferably an insulating object) may be placed in the high magnetic flux density region HB.

[0061] In order to prevent the copper pipes 1111a to 1111h and 1211a to 1211h from being placed in the high magnetic flux density region HB, the high magnetic flux density region HB is magnetic flux At a position farther from the conductor plate M than the high density region HB, magnetic flux It is preferable to arrange the first copper pipes 1111c, 1111d, 1211c, and 1211d so that at least a portion of their positions (y coordinates) in the heating longitudinal direction (y-axis direction) overlap with the density region HB. By arranging the first copper pipes 1111c, 1111d, 1211c, and 1211d in such positions, the number of copper pipes arranged in the heating longitudinal direction (y-axis direction) can be reduced. Therefore, the length of the induction heating device in the heating longitudinal direction can be shortened.

[0062] When cores 1120, 1220 are so-called E-shaped cores as shown in Figures 1 and 4, in order to prevent copper pipes 1111a-1111h, 1211a-1211h from being positioned in the high magnetic flux density region HB, it is preferable that, among the copper pipes positioned in one slot 1121a, 1121b, 1221a, 1221b of cores 1120, 1220, first copper pipes 1111c, 1111d, 1211c, 1211d positioned closest to first leg portions 1122, 1222 of cores 1120, 1220 be positioned farther from conductive plate M than the tip surfaces of first leg portions 1122, 1222 (end surfaces facing conductive plate M with a gap therebetween).

[0063] In the following explanation, magnetic flux At a position farther from the conductor plate M than the high density region HB, magnetic flux The first copper pipes arranged so that their positions (y coordinates) in the heating longitudinal direction (y axis direction) overlap at least partly with the density region HB are referred to as “retracted first copper pipes” as necessary. In Figures 1 and 3, copper pipes 1111c, 1111d, 1211c, and 1211d are illustrated as retracted first copper pipes.

[0064] 1, 3, and 4 illustrate a case where, in one slot 1121a, 1121b, 1221a, 1221b, the first copper pipes 1111a-1111b, 1111e-1111f, 1211a-1211b, 1211e-1211f are located closer to the conductor plate M than the retreating first copper pipes 1111c, 1111d, 1211c, 1211d.

[0065] Furthermore, if the copper pipes 1111a-1111h, 1211a-1211h are not to be placed in the high magnetic flux density region HB (the region with the highest magnetic flux density), the space for placing the first retracted copper pipes 1111c, 1111d, 1211c, 1211d in each slot 1121a, 1121b, 1221a, 1221b may become narrow. Therefore, it is preferable to realize at least one of the following (a) to (d):

[0066] (a) In one slot 1121a, 1121b, 1221a, 1221b, the number of first copper pipes and second copper pipes aligned in the plate thickness direction (z-axis direction) of the conductor plate M varies (changes) in the heating length direction (y-axis direction).

[0067] 1, 3, and 4, in one slot 1121a, the number of first copper pipes and second copper pipes aligned in the z-axis direction on the relatively positive side of the y-axis is 1 (see first copper pipe 1111c). Also, in one slot 1121a, the number of first copper pipes and second copper pipes aligned in the z-axis direction on the relatively central side of the y-axis is 2 (see first copper pipe 1111b and second copper pipe 1111g). Also, in one slot 1121a, the number of first copper pipes and second copper pipes aligned in the z-axis direction on the relatively negative side of the y-axis is 1 (see first copper pipe 1111a).

[0068] (b) In one slot 1121a, 1121b, 1221a, 1221b, the number of copper pipes aligned in the plate thickness direction (z-axis direction) of the conductor plate M is smallest at the position (y coordinate) in the heating longitudinal direction (y-axis direction) that overlaps with the high magnetic flux density region HB (the region with the highest magnetic flux density). Note that the position where the heating longitudinal direction (y-axis direction) overlaps with the high magnetic flux density region HB is the position where the first retreat copper pipe is located.

[0069] In the examples shown in Figures 1, 3, and 4, in one slot 1121a, the number of copper pipes lined up in the thickness direction (z-axis direction) of the conductive plate M is 1 (minimum) at the position (y-coordinate) in the heating length direction (y-axis direction) where it overlaps with the high magnetic flux density region HB (region with the highest magnetic flux density) (see the first copper pipe 1111c).

[0070] (c) In one of the slots 1121a, 1121b, 1221a, 1221b, the first copper pipe whose position (y coordinate) in the heating longitudinal direction (y axis direction) overlaps at least a portion with the high magnetic flux density region HB (the region with the highest magnetic flux density) is located farther from the conductive plate M than the other first copper pipes. Note that the first copper pipe whose position in the heating longitudinal direction overlaps with the high magnetic flux density region HB is the retreated first copper pipe.

[0071] In the examples shown in Figures 1, 3, and 4, in one slot 1121a, the first copper pipe 1111c, whose position (y coordinate) in the heating longitudinal direction (y-axis direction) overlaps at least a portion with the high magnetic flux density region HB (the region with the highest magnetic flux density), is located farther from the conductive plate M than the other first copper pipes 1111a and 1111b.

[0072] (d) In a cross section (y-z cross section) of the induction heating device 1000 taken perpendicular to the width direction (x-axis direction) of the conductive plate M, the first copper pipe and the second copper pipe are arranged in one of the slots 1121a, 1121b, 1221a, and 1221b asymmetrically with respect to the reference axis. The reference axis is a line that passes through the centroid of a figure defined by the outline of one slot that appears in the cross section (y-z cross section) taken perpendicular to the width direction (x-axis direction) of the conductive plate M and extends in the thickness direction (z-axis direction) of the conductive plate M. In other words, the first copper pipe and the second copper pipe arranged in one of the slots 1121a, 1121b, 1221a, and 1221b are not arranged in an axisymmetric relationship with respect to the reference axis. In addition, the cross section (yz cross section) obtained by cutting the induction heating device 1000 perpendicular to the width direction (x-axis direction) of the conductor plate M corresponds to the cross section obtained by cutting parallel to the heating length direction (y-axis direction) and the thickness direction (z-axis direction) of the conductor plate M.

[0073] In the examples shown in FIGS. 1, 3, and 4, the shapes defined by the outlines of the slots 1121a, 1121b, 1221a, and 1221b that appear in a cross section (yz cross section) taken perpendicular to the width direction (x-axis direction) of the conductive plate M are rectangles 1127a, 1127b, 1227a, and 1227b (See FIG. 1.) For convenience of notation, in FIG. 1, rectangles 1127a, 1127b, 1227a, 1227bThe imaginary lines representing the above are shown outside the actual contours of the slots 1121a, 1121b, 1221a, and 1221b (this also applies to FIG. 2, which will be described later). Note that the contours of the slots 1121a, 1121b, 1221a, and 1221b that open toward the conductive plate M do not actually exist (this also applies to FIG. 2, which will be described later). Furthermore, the contours of the slots 1121a, 1121b, 1221a, and 1221b that open toward the conductive plate M are, for example, straight lines connecting both ends of the opening of the slot in the shortest distance. The both ends of the opening of the slot are, for example, the end points of two legs (e.g., second leg 1123 and third leg 1124 that sandwich the slot 1121a) that are positioned to sandwich the slot therebetween, which are located on the metal plate M side and on the slot side.

[0074] Straight lines 1129a, 1129b, 1229a, and 1229b that pass through centroid positions 1128a, 1128b, 1228a, and 1228b of rectangles 1127a, 1127b, 1227a, and 1227b and extend in the thickness direction (z-axis direction) of conductive plate M are the axes of symmetry for each of slots 1121a, 1121b, 1221a, and 1221b. Note that straight lines 1129a, 1129b, 1229a, and 1229b are not actual lines.

[0075] For example, in one slot 1121a, the first copper pipes 1111a to 1111c and the second copper pipe 1111g are not in a line-symmetric relationship with respect to the straight line 1129a as the axis of symmetry.

[0076] Furthermore, the induction heating device 1000 may have a shield plate (not shown) for preventing overheating of the edge portions (edges in the width direction) of the conductor plate M. For example, the shield plate is disposed between the edge portions of the conductor plate M and the cores 1120, 1220, respectively. The shield plate moves according to the width of the conductor plate M and the amount of meandering (amount of movement in the width direction) of the conductor plate M. The shield plate is intended to prevent the main magnetic flux from passing through the edge portions of the conductor plate M.

[0077] (Induction heating device 2000) Next, the configuration of the induction heating device 2000 shown in FIG. 2 will be described. Induction heating device 2000 has an upper inductor 2100 and a lower inductor 2200. Upper inductor 2100 and lower inductor 2200 are arranged facing each other with conductive plate M sandwiched therebetween, with a gap between them in the thickness direction of conductive plate M. As with induction heating device 1000 shown in Fig. 1, induction heating device 2000 shown in Fig. 2 also illustrates a case where upper inductor 2100 and lower inductor 2200 are in a plane-symmetric relationship with imaginary plane SL as the plane of symmetry.

[0078] Upper inductor 2100 and lower inductor 2200 have coils 2110 and 2210 and cores 1120 and 1220, respectively. As mentioned above, induction heating device 1000 shown in Fig. 1 and induction heating device 2000 shown in Fig. 2 differ only in the number of turns (windings) of the coil. Therefore, an example of the configuration of induction heating device 2000 will be described below, but because the configuration of induction heating device 2000 shown in Fig. 2 can also be inferred from the description in the above-mentioned section (induction heating device 1000), detailed description of the reasons for adopting this configuration, advantages, etc. will be omitted.

[0079] In Fig. 3, the coils 2110 and 2210 have N turns (N is an integer of 2 or more). As described above, the number of turns of the coils 2110 and 2210 of the induction heating device 2000 shown in Fig. 2 is an odd number. Fig. 2 illustrates a case where the number of turns N of the coils 2110 and 2210 is 5, respectively. In an example described later with reference to Fig. 5, the coils 2110 and 2210 are connected in series. In this case, the total number of turns of the coils 2110 and 2210 in the induction heating device 2000 is 10 (= 2 x 5). On the other hand, 2210 When connected in parallel, the induction heating device 2000 Coil in 2110 , 2210 The total number of turns is 5.

[0080] FIG. 5 is a diagram showing an example of the configuration of the coils 2110 and 2210. As shown in FIG. The coils 2110 and 2210 have copper pipes 2111a to 2111j and 2211a to 2211j and copper bus bars 2112a to 2112j and 2212a to 2212j. 2000 5 illustrates a case where coils 2110 and 2210 are connected in series by copper bus bar 2130. Also, in FIG. 5, as in FIG. 3, arrows shown inside copper pipes 2111a-2111j, 2211a-2211j, copper bus bars 2112a-2112j, 2212a-2212j, and copper bus bar 2130 indicate the direction of AC current flowing through each part at the same time.

[0081] First, an example of the electrical connection relationship between the copper pipes 2111a to 2111j and 2211a to 2211j, the copper bus bars 2112a to 2112j and 2212a to 2212j, and the copper bus bar 2130 will be described.

[0082] One end of copper bus bar 2112a is electrically connected to one end 5001 of AC power supply 5000. The other end of copper bus bar 2112a is electrically connected to one end side (negative side of the x-axis) of copper pipe 2111g. One end of copper bus bar 2112b is electrically connected to the other end side (positive side of the x-axis) of copper pipe 2111g. The other end of copper bus bar 2112b is electrically connected to one end side (positive side of the x-axis) of copper pipe 2111j. One end of copper bus bar 2112c is electrically connected to the other end side (negative side of the x-axis) of copper pipe 2111j. As described above, the first turn (same turn) of coil 2110 is formed using copper bus bar 2112a, copper pipe 2111g, copper bus bar 2112b, and copper pipe 2111j. The copper bus bar 2112c serves to electrically connect the first turn and the second turn of the coil 2110.

[0083] The other end of copper bus bar 2112c is electrically connected to one end side (negative side of the x-axis) of copper pipe 2111a. One end of copper bus bar 2112d is electrically connected to the other end side (positive side of the x-axis) of copper pipe 2111a. The other end of copper bus bar 2112d is electrically connected to one end side (positive side of the x-axis) of copper pipe 2111f. One end of copper bus bar 2112e is electrically connected to the other end side (negative side of the x-axis) of copper pipe 2111f. As described above, the second turn (same turn) of coil 2110 is formed using copper pipe 2111a, copper bus bar 2112d, and copper pipe 2111f. Copper bus bar 2112e is used to electrically connect the second and third turns of coil 2110.

[0084] The other end of the copper bus bar 2112e is electrically connected to one end (negative side of the x-axis) of the copper pipe 2111h. One end of the copper bus bar 2112f is electrically connected to the other end (positive side of the x-axis) of the copper pipe 2111h. The other end of the copper bus bar 2112f is electrically connected to one end (positive side of the x-axis) of the copper pipe 2111i. One end of the copper bus bar 2112g is electrically connected to the other end (negative side of the x-axis) of the copper pipe 2111i. As described above, the third turn (same turn) of the coil 2110 is formed using the copper pipe 2111h, the copper bus bar 2112f, and the copper pipe 2111i. The copper bus bar 2112g is used to electrically connect the third turn and the fourth turn of the coil 2110.

[0085] The other end of copper bus bar 2112g is electrically connected to one end side (negative side of the x-axis) of copper pipe 2111b. One end of copper bus bar 2112h is electrically connected to the other end side (positive side of the x-axis) of copper pipe 2111b. The other end of copper bus bar 2112h is electrically connected to one end side (positive side of the x-axis) of copper pipe 2111e. One end of copper bus bar 2112i is electrically connected to the other end side (negative side of the x-axis) of copper pipe 2111e. As described above, the fourth turn (same turn) of coil 2110 is formed using copper pipe 2111b, copper bus bar 2112h, and copper pipe 2111e. Copper bus bar 2112i is used to electrically connect the fourth turn and fifth turn of coil 2110.

[0086] The other end of the copper bus bar 2112i is electrically connected to one end side (negative side of the x-axis) of the copper pipe 2111c. One end of the copper bus bar 2112j is electrically connected to the other end side (positive side of the x-axis) of the copper pipe 2111c. The other end of the copper bus bar 2112j is electrically connected to one end side (positive side of the x-axis) of the copper pipe 2111d. One end of the copper bus bar 2130 is electrically connected to the other end side (negative side of the x-axis) of the copper pipe 2111d. As described above, the fifth turn (same turn) of the coil 2110 is formed by using the copper pipe 2111c, the copper bus bar 2112j, and the copper pipe 2111d. As described above, the copper bus bar 2130 is electrically connected to the coils 2110, 2210 (coils 2110 The other end of the copper bus bar 2130 is electrically connected to one end (negative side of the x-axis) of the copper pipe 2221a of the coil 2210.

[0087] In the coil 2110 of the upper inductor 2100, the winding start portion of the first turn (copper bus bar 2112a) is electrically connected to one end 5001 of the AC power supply 5000. In contrast to this, in the coil 2210 of the lower inductor 2200, the winding start portion of the first turn (copper pipe 2211a) is electrically connected to the copper bus bar 2130. In addition, in the coil 2110 of the upper inductor 2100, the winding end portion of the fifth turn (copper pipe 2111d) is electrically connected to the copper bus bar 2130. Connect to On the other hand, in the coil 2210 of the lower inductor 2200, the winding end portion of the fifth turn (copper bus bar 2212j) is electrically connected to the other end 5002 of the AC power supply 5000.

[0088] Except for these points, the electrical connection relationship between copper pipes 2211a-2211j and copper bus bars 2212a-2212j of coil 2210 in lower inductor 2200 is similar to the electrical connection relationship between copper pipes 2111a-2111j and copper bus bars 2112a-2112j of coil 2110 in upper inductor 2100. Therefore, in describing coil 2210 in lower inductor 2200, a description will be given of copper pipes 2211a-2211j and copper bus bars 2212a-2212j used to form each turn, and a description of the specific connection relationship between copper pipes 2211a-2211j and copper bus bars 2212a-2212j used to form the first to fifth turns will be omitted.

[0089] First, copper pipe 2211a, copper bus bar 2212a, and copper pipe 2211f are used to form the first turn (same turn) of coil 2210. Copper bus bar 2212b is used to electrically connect the first turn and second turn of coil 2210.

[0090] Copper pipe 2211g, copper bus bar 2212c, and copper pipe 2211j form the second turn (same turn) of coil 2210. Copper bus bar 2212d is used to electrically connect the second turn and third turn of coil 2210.

[0091] Furthermore, copper pipe 2211b, copper bus bar 2212e, and copper pipe 2211e form the third turn (same turn) of coil 2210. Copper bus bar 2212f serves to electrically connect the third turn and fourth turn of coil 2210.

[0092] Furthermore, the copper pipe 2211h, copper bus bar 2212g, and copper pipe 2211i form the fourth turn (same turn) of the coil 2210. The copper bus bar 2212h serves to electrically connect the fourth turn and the fifth turn of the coil 2210.

[0093] Furthermore, the fifth turn (same turn) of coil 2210 is formed using copper pipe 2211c, copper bus bar 2212i, and copper pipe 2211d. One end of copper bus bar 2212j is electrically connected to the other end (negative side of the x-axis) of copper pipe 2211d. The other end of copper bus bar 2212j is electrically connected to other end 5002 of AC power supply 5000.

[0094] 2 and 5 show an example in which the copper pipes 2111a to 2111j and 2211a to 2211j have the same size and shape. The copper pipes 2111a to 2111j and 2211a to 2211j have a hollow rectangular parallelepiped shape. A cooling medium (for example, cooling water) is supplied to the hollow parts of the copper pipes 2111a to 2111j and 2211a to 2211j.

[0095] 5, as in FIG. 3, illustrates an example in which the conductor plate M is inductively heated by connecting the coils 2110 and 2210 in series, thereby causing the alternating current flowing through the coils 2110 and 2210 to cause the magnetic fluxes generated from the coils 2110 and 2210 to have substantially the same (preferably the same) direction at the same time, and by causing an alternating magnetic field to intersect substantially perpendicular (preferably perpendicular) to the plate surface of the conductor plate M.

[0096] However, the coils 2110 and 2210 may be connected in parallel as long as the alternating current flowing through the coils 2110 and 2210 causes the magnetic fluxes generated from the coils 2110 and 2210 to have substantially the same (preferably the same) direction at the same time, and the alternating magnetic fields are caused to intersect substantially perpendicular (preferably perpendicular) to the plate surface of the conductive plate M. Also, the coils 2110 and 2210 do not need to be electrically connected. In this case, the alternating currents flowing through the coils 2110 and 2210 are alternating currents supplied from separate alternating current power sources.

[0097] When the coils 2110 and 2210 are connected in parallel, for example, the copper bus bar 2130 is not necessary. Instead, one end side (negative side of the x-axis) of the copper pipe 2211a of the coil 2210 is connected to one end 5001 of the AC power supply 5000 via the copper bus bar 2112a or the like. 2110 The other end (negative side of the x-axis) of the copper pipe 2111d of the coil is connected to the other end 5002 of the AC power supply 5000. 2110 The other end (negative side of the x-axis) of copper pipe 2111d may be connected to other end 5002 of AC power supply 5000 via copper bus bar 2212j or the like. When coils 2110 and 2210 are connected in parallel, the total number of turns of coils 2110 and 2210 in induction heating device 2000 is five.

[0098] 5 illustrates, for convenience of notation, a case where, of two copper pipes 2211a and 2211g, and two copper pipes 2211e and 2211i arranged in the thickness direction (z-axis direction) of the conductive plate M in the coil 2210, the copper pipes 2211a and 2211e, which are closer to the conductive plate M, are wound first. Specifically, a case where the copper pipe 2211a is wound in the first turn and the copper pipe 2211g is wound in the second turn is illustrated. Also, a case where the copper pipe 2211e is wound in the third turn and the copper pipe 2211i is wound in the fourth turn is illustrated. However, the path through which the AC current flows in the coil 2110 and the path through which the AC current flows in the coil 2220 may be symmetrical with respect to the imaginary plane SL. In this case, for example, the winding order of copper pipes 2221g and 2221j, which are arranged at positions far from the conductive plate M, may be set to precede the winding order of copper pipes 2211a and 2221e.

[0099] The cores 1120 and 1220 of the induction heating device 2000 shown in Fig. 2 are the same as the cores 1120 and 1220 of the induction heating device 1000 described with reference to Fig. 4. As described with reference to Fig. 3, also in Fig. 5, the copper bus bars 2112a-2112j and 2212a-2212j are attached to the copper pipes 2111a-2111j and 2211a-2211j, respectively, avoiding the areas of the copper pipes 2111a-2111j and 2211a-2211j that are attached to the cores 1120 and 1220.

[0100] Similar to the induction heating device 1000 described with reference to Figures 1 and 3, the induction heating device 2000 shown in Figures 2 and 5 also has coils 2110 and 2210 each having a plurality of copper pipes 2111a-2111j and 2211a-2211j electrically connected to one another. In the example shown in Figures 2 and 5, the copper pipes 2111a-2111j and 2211a-2211j are examples of conductors. At least two of the copper pipes 2111a-2111j and 2211a-2211j are placed in one of the slots 1121a, 1121b, 1221a, and 1221b, respectively.

[0101] At least one first copper pipe 2111a to 2111f, 2211b is inserted into each slot 1121a, 1121b, 1221a, 1221b. a~ 2211f will be placed.

[0102] Furthermore, at least one second copper pipe 2111g to 2111h, 2111i to 2111j, 2211g to 2211h, or 2211i to 2211j is arranged in each of the slots 1121a, 1121b, 1221a, and 1221b.

[0103] 2 and 5, the first copper pipes 2111a to 2111f and 2211a to 2211f are an example of the first conductor portion, and the second copper pipes 2111g to 2111h, 2111i to 2111j, 2211g to 2211h and 2211i to 2211j are an example of the second conductor portion.

[0104] In one slot 1121a, 1121b, 1221a, 1221b, the first copper pipes 2111a to 2111f, 2211a to 2211f and the second copper pipes 2111g to 2111h, 2111i to 2111j, 2211g to 2211h, 2211i to 2211j configure different turns in the coils 2110, 2210, respectively.

[0105] For example, as described above, the first copper pipes 2111a and 2111f are the second turn of the coil 2110, and the second copper pipes 2111g and 2111j are the first turn of the coil 2110. Therefore, the first copper pipes 2111a and 2111f and the second copper pipes 2111g and 2111j are the first turn of the coil 2110. 2111j and constitute different turns in the coil 2110. In this case, the first copper pipes 2111a and 2111f and the second copper pipes 2111g and 2111jand are connected in series. Furthermore, the first copper pipes 2111b and 2111e form the fourth turn of the coil 2110, and the second copper pipes 2111h and 2111i form the third turn of the coil 2110. Therefore, the first copper pipes 2111b and 2111e and the second copper pipes 2111h and 2111i form different turns in the coil 2110. In this case, the first copper pipes 2111b and 2111e and the second copper pipes 2111h and 2111i are connected in series.

[0106] Similarly, the first copper pipes 2211a and 2211f and the second copper pipes 2211g and 2211j form different turns in the coil 2210. In this case, the first copper pipes 2211a and 2211f and the second copper pipes 2211g and 2211j are connected in series. Also, the first copper pipes 2211b and 2211e and the second copper pipes 2211h and 2211i form different turns in the coil 2210. In this case, the first copper pipes 2211b and 2211e and the second copper pipes 2211h and 2211i are connected in series.

[0107] 2 and 5, it is also preferable that the first copper pipes 2111a-2111f and 2211a-2211f have different turns in each slot 1121a, 1121b, 1221a, and 1221b.It is also preferable that the second copper pipes 2111g-2111h, 2111i-2111j, 2211g-2211h, and 2211i-2211j have different turns in each slot 1121a, 1121b, 1221a, and 1221b.

[0108] It is also preferable to arrange multiple copper pipes 2111a to 2111c (and 2111g, 2111h, 2111c), 2111d to 2111f (and 2111d, 2111i, 2111j), 2211a to 2211c (and 2211g, 2211h, 2211c), and 2211d to 2211f (and 2111d, 2111i, 2211j) in the heating longitudinal direction (y-axis direction).

[0109] It is also preferable that the copper pipes 2111a to 2111j and 2211a to 2211j are not arranged in the high magnetic flux density region HB. When the copper pipes 2111a to 2111j and 2211a to 2211j are not arranged in the high magnetic flux density region HB, the copper pipes 2111a to 2111j and 2211a to 2211j are arranged in the high magnetic flux density region HB in one slot 1121a, 1121b, 1221a, 1221b at a position farther from the conductor plate M than the high magnetic flux density region HB. magnetic flux It is preferable to arrange the first retracting copper pipes 2111c, 2111d, 2211c, and 2211d so that at least a part of the position (y coordinate) in the heating longitudinal direction (y axis direction) overlaps with the density region HB.

[0110] When cores 1120, 1220 are so-called E-shaped cores as shown in Figures 2 and 5, in order to prevent copper pipes 2111a-2111j, 2211a-2211j from being positioned in the high magnetic flux density region HB, it is preferable that, among the copper pipes positioned in one slot 1121a, 1121b, 1221a, 1221b of cores 1120, 1220, the first retracted copper pipes 2111c, 2111d, 2211c, 2211d positioned closest to first leg portions 1122, 1222 of cores 1120, 1220 are positioned farther from conductor plate M than the tip surfaces of first legs 1122, 1222.

[0111] 2, 4, and 5 illustrate a case where, in one slot 1121a, 1121b, 1221a, 1221b, first copper pipes 2111a-2111b, 2111e-2111f, 2211a-2211b, 2211e-2211f are located closer to the conductor plate M than the retreating first copper pipes 2111c, 2111d, 2211c, 2211d.

[0112] Furthermore, when copper pipes 2111a to 2111j and 2211a to 2211j are not to be placed in a high magnetic flux density region HB (region with the highest magnetic flux density), it is preferable to realize at least one of the above-mentioned (a) to (d).

[0113] Regarding (a) above, in the examples shown in FIGS. 2, 4, and 5, in one slot 1121a, the number of first copper pipes and second copper pipes aligned in the z-axis direction on the relatively positive side of the y-axis is 1 (see first copper pipe 2111c). Also, in one slot 1121a, the number of first copper pipes and second copper pipes aligned in the z-axis direction on the relatively central side of the y-axis is 2 (see first copper pipe 2111b and second copper pipe 2111h). Also, in one slot 1121a, the number of first copper pipes and second copper pipes aligned in the z-axis direction on the relatively negative side of the y-axis is 2 (see first copper pipe 2111a and second copper pipe 2111g).

[0114] Regarding (b) above, in the examples shown in Figures 2, 4, and 5, in one slot 1121a, the number of first copper pipes and second copper pipes lined up in the thickness direction (z-axis direction) of the conductor plate M is 1 (minimum) at the position (y-coordinate) in the heating length direction (y-axis direction) where it overlaps with the high magnetic flux density region HB (region with the highest magnetic flux density) (see first copper pipe 2111c).

[0115] Regarding the above-mentioned (c), in the examples shown in Figures 2, 4, and 5, in one slot 1121a, the first copper pipe 2111c, whose position (y coordinate) in the heating longitudinal direction (y axis direction) overlaps with the high magnetic flux density region HB (the region with the highest magnetic flux density), is located farther from the conductive plate M than the other first copper pipes 2111a and 2111b.

[0116] Regarding the above-mentioned (d), in the examples shown in Figures 2, 4, and 5, the figures defined by the outlines of one slot 1121a, 1121b, 1221a, and 1221b that appear in a cross section (yz cross section) when cut perpendicular to the width direction (x-axis direction) of the conductive plate M are rectangles 2127a, 2127b, 2227a, and 2227b, respectively (see Figure 2).

[0117] Therefore, straight lines 2129a, 2129b, 2229a, and 2229b that pass through centroid positions 2128a, 2128b, 2228a, and 2228b of rectangles 2127a, 2127b, 2227a, and 2227b and extend in the thickness direction (z-axis direction) of conductive plate M become the axes of symmetry for one slot 1121a, 1121b, 1221a, and 1221b, respectively. Note that straight lines 2129a, 2129b, 2229a, and 2229b are not actual lines.

[0118] For example, in one slot 1121a, the first copper pipes 2111a to 2111c and the second copper pipes 2111g to 2111h are not in a line-symmetric relationship with respect to the straight line 2129a as the axis of symmetry.

[0119] Furthermore, similar to the induction heating device 1000, the induction heating device 2000 may also have a shield plate (not shown).

[0120] (Design method) Next, an example of a design method for the copper pipes 1111a-1111h, 1211a-1211h, 2111a-2111j, 2211a-2211j and the cores 1120, 1220 will be described, which is for configuring an induction heating device so that it has the heating capacity required to heat the conductor plate M while suppressing an increase in the length of the induction heating device in the heating longitudinal direction (y-axis direction). For simplicity of explanation, the case will be illustrated where the copper pipes 1111a-1111h, 1211a-1211h, 2111a-2111j, 2211a-2211j have the same shape and size. Furthermore, the current density of the AC current that can be passed through the copper bus bars 1112a to 1112h, 1212a to 1212h, 2112a to 2112j, and 2212a to 2212j is equal to or greater than the current density of the AC current that can be passed through the copper pipes 1111a to 1111h, 1211a to 1211h, 2111a to 2111j, and 2211a to 2211j.

[0121] Therefore, when designing copper pipes, the following four points must be taken into consideration: The current value (effective value) of the AC current that can be passed through the coil The relationship between the flow rate of the cooling medium (e.g., cooling water) that can be flowed through the hollow part of the copper pipe and the structure of the copper pipe The relationship between the copper pipe structure and the depth and width of the core slot (length in the heating direction (y-axis direction)) The relationship between the width of the slot in the core and the spacing between the coils of the upper and lower inductors

[0122] 1 and 2, the width (length in the heating length direction (y-axis direction)) of the copper pipes 1111a-1111h, 1211a-1211h, 2111a-2111j, and 2211a-2211j is defined as D1 (mm). The height (length in the plate thickness direction (z-axis direction) of the copper pipes 1111a-1111h, 1211a-1211h, 2111a-2111j, and 2211a-2211j) is defined as D2 (mm). The width of the slots 1121a, 1121b, 1221a, and 1221b is defined as K1 (mm). The depth of the slots 1121a, 1121b, 1221a, and 1221b is defined as K2 (mm).

[0123] FIG. 6 is a diagram illustrating an example of penetration depth δ. In a transverse type induction heating device, as shown in FIG. 6, AC current does not flow uniformly within the coil, but flows concentratedly on the conductive plate M side. The gray area in FIG. 6 indicates the area through which AC current flows. Penetration depth δ (mm) is the depth from the surface of the coil (copper pipe) on the conductive plate M side, and is expressed by the following equation (1). δ=503.3×{ρ÷(μ r ×f)} 0.5 x10 3 ···(1) Here, ρ is the resistivity of the conductor that makes up the coil (×10 -8 Ω m). μ r is the relative permeability of the conductor that makes up the coil. f is the frequency (Hz) of the alternating current flowing through the coil.

[0124] The current value I1 (A) of the AC current flowing through the coil is determined by the cross-sectional area of ​​the coil (copper pipe), and the current density I2 (A / mm 2) multiplied by the cross-sectional area of ​​the AC current flowing through the coil (copper pipe). The current density I2 of the AC current, which is determined from the cross-sectional area of ​​the coil (copper pipe), can be obtained by dividing the current value I1 of the AC current flowing through the coil by the cross-sectional area of ​​the coil (copper pipe) (the area of ​​the region indicated by the solid line in Figure 6). Also, the cross-sectional area of ​​the AC current flowing through the coil (copper pipe) is the area of ​​the region indicated in gray in Figure 6 (= δ × D1). Therefore, the following equation (2) holds true, and by transforming equation (2), the following equation (3) is obtained. I1=D1×δ×I2 (2) I2 = I1 ÷ (D1 × δ) (3)

[0125] The allowable current density I2 of the AC current determined by the cross-sectional area of ​​the conductor (copper pipe) that makes up the coil is I 2max (A / mm 2 ), the following formula (4) must be satisfied. In the following description, this current density will be referred to as the allowable current density as necessary. I 2max ≧I1÷(D1×δ) (4) From equations (3) and (4), the following equation (5) is established. I1÷(I 2max × δ)≦D1=I1÷(I2×δ) (5)

[0126] The width D1 of the copper pipes 1111a to 1111h, 1211a to 1211h, 2111a to 2111j, and 2211a to 2211j is determined by equation (5). 2max For example, 40A / mm 2 However, the allowable current density I 2max is 40A / mm 2 It is not limited to the allowable current density I 2max For example, 60A / mm 2 Preferably, it is:

[0127] Let the volumetric flow rate of the cooling medium (e.g., cooling water) flowing through the hollow part of the copper pipe be L (l / min). Let the allowable flow rate of the cooling medium be v max(m / s). Then, it is necessary to satisfy the following equation (6). The allowable flow velocity v of the cooling medium max is determined based on, for example, the reduction in the cooling performance of the copper pipe by the cooling medium due to the occurrence of cavitation. The allowable flow velocity v of the cooling medium max is, for example, 5 m / s. However, the allowable flow velocity v of the cooling medium max is not limited to 5 m / s. D2 ≧ L÷(v max × 60 × D1 × 10 -3 ) ···(6)

[0128] In equation (6), "L÷(v max × 60 × 10 -3 )" is the area of the hollow part of the copper pipe that must be ensured at least to allow the cooling medium to flow (the area of the region shown by the broken line in Fig. 6 (mm 2 )). According to equation (6), the height D2 of the copper pipes 1111a~1111h, 1211a~1211h, 2111a~2111j, and 2211a~2211j is determined. In Figs. 1 and 2, the case where the width D1 of the copper pipes 1111a~1111h, 1211a~1211h, 2111a~2111j, and 2211a~2211j is longer than the height D2 of the copper pipes 1111a~1111h, 1211a~1211h, 2111a~2111j, and 2211a~2211j is illustrated. However, it is not necessarily required to be like this. The former may be shorter than the latter, or the former and the latter may be the same (that is, D1 < D2 is also acceptable, or D1 = D2 is also acceptable).

[0129] When equation (6) is transformed, it becomes the following equation (7). L÷(v max × 60 × 10 -3 ) ≦ D1 × D2 ···(7) In equation (6), assuming that the penetration depth δ is small (that is, assuming that the area of the hollow rectangular region shown by the solid-line slanted lines in Fig. 6 is 0 (zero)), as in equation (7), the area of the hollow part of the copper pipe that must be ensured at least to allow the cooling medium to flow (= L÷(v maxx60x10 -3 )) is equal to or greater than the area (=D1×D2)) of the rectangular region indicated by the solid and dashed diagonal lines in Fig. 6. However, in order to determine the height D2 of the copper pipes 1111a to 1111h, 1211a to 1211h, 2111a to 2111j, and 2211a to 2211j more accurately, instead of "D1×D2" in equation (7), the area (mm 2 ) may also be adopted.

[0130] The heating capacity P of the induction heating device is expressed by the following formula (8a) or (8b). P = (2N × I1) 2 (8a) P = (N × I1) 2 (8b) Equation (8a) shows the heating capacity P of the induction heating device when the coils 1110, 2110 of the upper inductors 1100, 2100 and the coils 1210, 2210 of the lower inductors 1200, 2200 are connected in series, as shown in Figures 3 and 5. Equation (8b) shows the heating capacity P of the induction heating device when it is assumed that the coils 1110, 2110 of the upper inductors 1100, 2100 and the coils 1210, 2210 of the lower inductors 1200, 2200 are connected in parallel, as described above as a modification of Figures 3 and 5.

[0131] As shown in equations (8a) and (8b), the heating capacity P of the induction heating device can be increased by increasing the number of turns N of the coil. To achieve this, it is possible to shorten the width D1 of the copper pipe extremely. However, if the width D1 of the copper pipe is shortened extremely, there is a risk that the width D1 and height D2 of the copper pipe cannot be determined to satisfy equations (5) and (6). Therefore, as described above in the sections (induction heating device 1000) and (induction heating device 2000), by arranging a second copper pipe farther from the conductor plate M than the first copper pipe so that at least a portion of the second copper pipe overlaps with the first copper pipe in the heating longitudinal direction (y-axis direction) (y-coordinate), the heating capacity of the induction heating device can be increased without increasing the width of the copper pipe. Specifically, by determining the depth K2 of slots 1121a, 1121b, 1221a, and 1221b so as to satisfy the following equation (9), at least one second copper pipe can be positioned farther from the conductor plate M than the first copper pipe so that at least a portion of its position (y coordinate) in the heating longitudinal direction (y-axis direction) overlaps with the first copper pipe. K2 ≥ 2 × D2 (9) The depth K2 of the slots 1121a, 1121b, 1221a, and 1221b is determined by equation (9).

[0132] Furthermore, when the number of turns N of the coil is an odd number (N≧3), the following formula (10a) holds: When the number of turns N of the coil is an even number (N≧2), the following formula (10b) holds: K1≧D1×{0.5×(N+1)} ···(10a) K1≧D1×(0.5×N+1) ···(10b) The width K1 of the slots 1121a, 1121b, 1221a, and 1221b is determined by equations (10a) and (10b).

[0133] 1 and 3 illustrate an example in which the number of turns N of coils 2110, 2210 is 4. Also, FIGS. 2 and 5 illustrate an example in which the number of turns N of coils 2110, 2210 is 5. However, the number of turns N of the coil may be 2 or more. The number of turns N of the coil is determined, for example, so that the voltage and current required to obtain the capacity required to heat the conductive plate are applied to the coil within a range that can be applied to the coil.

[0134] 1 and 2, it is preferable that copper pipes 1111c-1111d, 1211c-1211d, 2111c-2111d, 2211c-2211d, which are arranged closest to first legs 1122, 1222 of cores 1120, 1220, are arranged farther from conductor plate M than the tip faces (end faces facing conductor plate M with a gap between them) of first legs 1122, 1222. The present inventors have found, from the results of electromagnetic field analysis of an induction heating device and other factors, that it is even more preferable to satisfy the following formula (11): d≧K2÷5 (11)

[0135] 1 and 2, d (mm) is the distance in the thickness direction (z-axis direction) of the conductor plate M between the surfaces of the retracting first copper pipes 1111c, 1111d, 1211c, 1211d, 2111c, 2111d, 2211c, and 2211d facing the conductor plate M and the tip faces of the first legs 1122 and 1222 of the cores 1120 and 1220. In this embodiment, by satisfying formula (11), the distance in the thickness direction (z-axis direction) of the conductor plate M between the first conductor (e.g., the retracting first copper pipe 1111c) located closest to the first leg (e.g., the first leg 1122) of the core and the tip face of the first leg is realized to be 1 / 5 or more of the slot depth (e.g., the depth K2 of the slot 1121a).

[0136] (Variation) Next, a modification of this embodiment will be described. In this embodiment, as shown in FIGS. 1 and 2, the maximum number of copper pipes 1111a-1111h, 1211a-1211h, 2111a-2111j, and 2211a-2211j arranged in one slot 1121a, 1121b, 1221a, and 1221b in the thickness direction (z-axis direction) of the conductor plate M is two. However, the maximum number of copper pipes arranged in one slot of the core in the thickness direction (z-axis direction) of the conductor plate M may be three or more. FIG. 7 is a diagram showing an example of the configuration of an induction heating device 7000 in this case. Similar to FIGS. 1 and 2, FIG. 7 is a diagram showing a cross section cut perpendicular to the width direction (x-axis direction) of the conductor plate M. In FIG. 7, the induction heating device 7000 includes an upper inductor 7100 and a lower inductor 7200. The upper inductor 7100 and the lower inductor 7200 respectively have coils 7110 and 7210 and cores 7120 and 7220. In FIG. 7, in one slot of the cores 7120 and 7220, copper pipes 7111a to 7111p and 7211a to 7211p are arranged in the thickness direction (z-axis direction) of the conductor plate M. 7211p Here is an example where the maximum number of rows is 3.

[0137] 1 and 2, in one slot (e.g., slot 1121a), the maximum number of second copper pipes arranged farther from the conductor plate M than the first copper pipes 1111a-1111f, 1211a-1211f, 2111a-2111f, and 2211a-2211f so as to overlap at least a portion of their positions (y coordinates) in the heating longitudinal direction (y axis direction) with the first copper pipes 1111a-1111f, 1211a-1211f, 2111a-2111f, and 2211a-2211f is 1 (see second copper pipes 1111g, 1111h, 1211g, 1211h, 2111g-2111h, 2111i-2111j, 2211g-2211h, and 2211i-2211j). However, the maximum number of such second copper pipes may be 2 or more. FIG. 7 illustrates an example in which the maximum number of such second copper pipes is 2 (second copper pipes 7111g to 7111h, 7111i to 7111j, 7111m to 7111n, 7111o to 7111p, 7211g ~ 7211h, 7211i–7211j, 7211m–7211n, 7211o–7211p).

[0138] Furthermore, in this embodiment, a case has been illustrated in which there is no second copper pipe positioned farther from the conductor plate M than the retreating first copper pipes 1111c, 1111d, 1211c, 1211d, 2111c, 2111d, 2211c, and 2211d so as to overlap at least a portion of the position (y coordinate) in the heating longitudinal direction (y axis direction) with the retreating first copper pipes. However, a second copper pipe may be positioned farther from the conductor plate M than the retreating first copper pipe so as to overlap at least a portion of the position (y coordinate) in the heating longitudinal direction (y axis direction) with the retreating first copper pipe. FIG. 7 illustrates a case in which second copper pipes 7111k to 7111l and 7211k to 7211l are such second copper pipes.

[0139] In this embodiment, the second copper pipes 1111g-1111h, 1211g-1211h are arranged so that the entire position (y-coordinate) of each second copper pipe 1111b, 1111e, 1211b, 1211e, 2111a-2211b, 2111e-2111f, 2211a-2211b, 2211e-2211f overlaps with the first copper pipe 1111b, 1111e, 1211b-1211f, 2211a-2211b, 2211e-2211f. However, the second copper pipes may be arranged so that the entire position (y-coordinate) of each second copper pipe overlaps with the first copper pipe 1111b, 1111e, 1211g-1211h. FIG. 8 illustrates an example of the configuration of an induction heating device 8000 in this case. Similar to FIGS. 1 and 2, FIG. 8 illustrates a cross section of the conductive plate M taken perpendicular to the width direction (x-axis direction). 8, the induction heating device 8000 has an upper inductor 8100 and a lower inductor 8200. The upper inductor 8100 and the lower inductor 8200 have coils 8110 and 8210 and cores 1120 and 1220, respectively. The induction heating device 8000 shown in FIG. 8 is similar to the induction heating device 1000 shown in FIG. 1 except for the second copper pipes 1111g, 1111h, and 1211g. 1211hIn FIG. 8, the positions of the second copper pipes 1111g, 1111h, 1211g, 1211h, 1211i, 1211j, 1211k ... 1211h are respectively arranged as an example.

[0140] In this embodiment, the first retracted copper pipes 1111c, 1111d, 1211c, 1221d, 2111c, 2111d, 2211c, and 2221d are located farther from the conductor plate M than the other first copper pipes 1111a-1111b, 1111e-1111f, 1211a-1211b, 1211e-1211f, 2111a-2111b, 2111e-2111f, 2211a-2211b, and 2211e-2211f, respectively, in one slot 1121a, 1121b, 1221a, and 1221b. However, this is not necessarily the case. FIG. 9 is a diagram showing an example of the configuration of an induction heating device 9000 in this case. 9, like FIGS. 1 and 2, is a diagram showing a cross section cut perpendicular to the width direction (x-axis direction) of conductive plate M. In FIG. 9, induction heating device 9000 has upper inductor 9100 and lower inductor 9200. Upper inductor 9100 and lower inductor 9200 have coils 9110 and 9210 and cores 9120 and 9220, respectively. In induction heating device 9000 shown in FIG. 9, the positions of first copper pipes 1111a-1111b, 1111e-1111f, 1211a-1211b, and 1211e-1211f and the positions of second copper pipes 1111g, 1111h, 1211g, and 1211h are changed compared to induction heating device 1000 shown in FIG. 1, and the slots in cores 9120 and 9220 are made deeper. 9 illustrates a case where the positions of the retracted first copper pipes 1111c, 1111d, 1211c, and 1211d in the plate thickness direction (z-axis direction) of the conductor plate M are the same as the positions of the other first copper pipes 1111a-1111b, 1111e-1111f, 1211a-1211b, and 1211e-1211f in the plate thickness direction (z-axis direction) of the conductor plate M. Also, FIG. 9 illustrates a case where the first copper pipes 1111a-1111f and 1211a-1211f are arranged farther from the conductor plate M than the tip faces (end faces facing the conductor plate M with a gap) of the first legs of the cores 9120 and 9220, respectively.

[0141] In addition, in the present embodiment, the first copper pipes 1111a-1111f, 1211a-1211f and the second copper pipes 1111g-1111h, 1211g-1211h form different turns in one slot 1121a, 1121b, 1221a, 1221b. That is, in the present embodiment, all of the first copper pipes 1111a-1111f, 1211a-1211f arranged in one slot 1121a, 1121b, 1221a, 1221b form different turns from all of the second copper pipes 1111g-1111h, 1211g-1211h arranged in that slot. In this case, among the first copper pipes 1111a to 1111f, 1211a to 1211f placed in one slot 1121a, 1121b, 1221a, 1221b, there is no copper pipe connected in parallel to the second copper pipes 1111g to 1111h, 1211g to 1211h placed in that slot.

[0142] This is preferable because it increases the number of turns N of the coils 1110 and 1210 while preventing the induction heating device 1000 or 2000 from becoming longer in the heating length direction (y-axis direction). However, this is not necessarily required as long as there is at least one first copper pipe and one second copper pipe in each slot 1121a, 1121b, 1221a, or 1221b that form different turns in the coils 1110, 1210, 2110, or 2210. In other words, it is sufficient that at least one first copper pipe in each slot 1121a, 1121b, 1221a, or 1221b is connected in series with the second copper pipe in that slot. This is because it increases the number of turns N of the coil while preventing the induction heating device from becoming longer in the heating length direction (y-axis direction) compared to when this is not done.

[0143] In this embodiment, the first copper pipes 1111a-1111f, 1211a-1211f and the second copper pipes 1111g-1111h, 1211g-1211h in each slot 1121a, 1121b, 1221a, and 1221b are identical in size and shape. However, this is not necessarily the case. For example, in each slot 1121a, 1121b, 1221a, and 1221b, the copper pipes other than the retreating first copper pipe may be shorter in the thickness direction (z-axis direction) of the conductor plate M than the retreating first copper pipe. Furthermore, in this state, the end face of the retreating first copper pipe facing the conductor plate M and the end faces of the other first copper pipes facing the conductor plate M may be positioned at the same position in the thickness direction (z-axis direction) of the conductor plate M. This allows the core slots to be shallower than the example shown in FIG. 9 .

[0144] Furthermore, in this embodiment, the cores 1120 and 1220 have three legs (so-called E-shaped cores) as an example. However, the number of legs that the core has is not limited to three. The number of legs that the core has may be two, or may be four or more. When separate coils are arranged on the multiple legs that the core has, it is preferable that all of these coils have the first copper pipe and the second copper pipe determined as described above. Compared to when this is not done, it is possible to increase the number of turns N of the coil while suppressing an increase in the length of the induction heating device in the heating length direction (y-axis direction). do This is because this can be achieved for the coils arranged on all legs. However, it is sufficient that at least one pair of coils among those pairs that are positioned opposite each other in the plate thickness direction (z-axis direction) of the conductor plate M has the first copper pipe and the second copper pipe determined as described above. This is because, compared to when this is not done, it is possible to increase the number of turns N of the coil while preventing the length of the induction heating device in the heating length direction (y-axis direction) from becoming too long.

[0145] (Other embodiments) It should be noted that the above-described embodiments of the present invention are merely examples of specific embodiments for carrying out the present invention, and the technical scope of the present invention should not be construed as being limited by these. In other words, the present invention can be embodied in various forms without departing from its technical concept or main features. [Industrial Applicability]

[0146] The present invention can be used, for example, to heat a conductive plate.

Claims

1. an upper inductor and a lower inductor arranged to face each other with a conductor plate therebetween; A transverse type induction heating device that inductively heats a conductor plate by crossing an alternating magnetic field across a plate surface of the conductor plate, each of the upper inductor and the lower inductor has a coil and a core; The number of turns of the coil is 2 or more, the core has a slot which is a space in which the coil is disposed, the coil has a plurality of conductor portions electrically connected to each other; The conductor portion includes at least one first conductor portion and at least one second conductor portion, The first conductor portion is the conductor portion that is located closest to the conductor plate at each position in the heating longitudinal direction in one of the slots, the second conductor portion is the conductor portion that is disposed in one of the slots at a position farther from the conductor plate than at least one of the first conductor portions, In one slot, at least a portion of a position of at least one of the first conductors in the heating longitudinal direction and at least a portion of a position of at least one of the second conductors in the heating longitudinal direction overlap with each other, the heating longitudinal direction is a direction parallel to the conveying direction of the conductor plate, At least one of the second conductor portions is electrically connected in series to the first conductor portion in one of the slots, A transverse type induction heating device in which the conductor portion is not positioned in an area of ​​the slot in which the conductor portion is positioned with the highest magnetic flux density when the core is excited by an alternating current flowing through the coil.

2. 2. The transverse type induction heating device according to claim 1, wherein the first conductor portion is arranged at a position farther from the conductor plate than the region with the highest magnetic flux density, so that at least a portion of the position in the heating longitudinal direction overlaps with the region with the highest magnetic flux density.

3. the core has a first leg, a second leg, and a third leg; the second leg portion and the third leg portion are arranged on both sides of the first leg portion in the heating longitudinal direction with a gap therebetween, 3. A transverse type induction heating device as described in claim 1 or 2, wherein the first conductor portion located closest to the first leg portion in one of the slots is located farther from the conductor plate than the tip surface of the first leg portion.

4. 4. The transverse type induction heating device according to claim 3, wherein the distance in the thickness direction of the conductor plate between the first conductor portion located closest to the first leg portion in one of the slots and the tip surface of the first leg is 1 / 5 or more times the depth of the slot.

5. 3. The transverse type induction heating device according to claim 1, wherein a plurality of the conductor portions are arranged in one slot in the heating longitudinal direction.

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