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

Transverse type induction heating device

[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.

[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] A transverse induction heating device is disclosed in Patent Document 1. 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 the upper and lower coils. Here, the coil width is the length of the coil in the direction of transport of the conductor plate to be heated.

[0004] JP 2010-27470 A

[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, the length of the induction heating device (coil width, slot width) in the direction of transport of the conductive plate to be heated must be increased. 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 (note 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.

[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 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 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, and the second conductor portion is the conductor portion that is located farther from the conductor plate than at least one of the first conductor portions in one of the slots, and in one of the slots, at least a portion of the position in the heating longitudinal direction of at least one of the first conductor portions overlaps with at least a portion of the position in the heating longitudinal direction of at least one of the second conductor portions, the heating longitudinal direction is a direction parallel to the transport direction of the conductor plate, and one of the slots has at least one second conductor portion that is electrically connected in series to the first conductor portion.

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

[0009] An embodiment of the present invention will be described below with reference to the drawings. The term "sameness" in terms of length, position, size, spacing, etc., includes not only exact identicalness but also differences within the spirit of the invention (e.g., differences within the tolerances established at the time of design). For ease of explanation and notation, only the parts necessary for the explanation are shown in simplified form as needed in each figure. In addition, the x-y-z coordinates in each figure indicate the orientation relationship in each figure. A symbol with a cross mark (x) inside a white circle (○) indicates that the axis extending from the front to the back of the page is the positive direction. This embodiment illustrates a case in which the x-y plane is the horizontal plane and the z-axis direction is the height direction.

[0010] FIG. 1 is a diagram showing a first example of a transverse-type induction heating device. FIG. 2 is a diagram showing 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 (D １ , D ２ , K. １ , K. ２ etc.) will be described later in the (Design Method) section.

[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 facing each other with a gap in the thickness direction (z-axis direction) of the conductor plate M. 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. The virtual surface SL is not an actual surface.

[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, for example, such that the center lines of the coils 1110 and 1210 are substantially perpendicular (preferably perpendicular) to the plate surface of the conductor plate M. The number of turns in the coils 1110 and 1210 is N (N is an integer equal to or greater than 2). As described above, the number of turns in the coils 1110 and 1210 of the induction heating device 1000 shown in FIG. 1 is an even number. FIG. 1 illustrates an example in which the number of turns N in the coils 1110 and 1210 is 4. In an example described below with reference to FIG. 3, the coils 1110 and 1210 are electrically connected in series. In this case, the total number of turns in the coils 1110 and 1210 of the induction heating device 1000 is 8 (= 2 × 4). On the other hand, when 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 four. Note that "electrically connected in series" has the same meaning as the series connection commonly used in the field of electric circuits. Also, "electrically connected in parallel" has the same meaning as the parallel connection commonly used in the field of electric circuits. In the following description, "electrically connected in series" will be simply referred to as "connected in series" as necessary. Also, "electrically connected in parallel" will be simply referred to as "connected in parallel" as necessary.

[0014] FIG. 3 is a diagram showing an example of the configuration of coils 1110 and 1210. In FIG. 3, coils 1110 and 1210 include copper pipes 1111a to 1111h and 1211a to 1211h, and copper bus bars 1112a to 1112h and 1212a to 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 to 1111h and 1211a to 1211h, copper bus bars 1112a to 1112h and 1212a to 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 and 1211a to 1211h, the copper bus bars 1112a to 1112h and 1212a to 1212h, and the copper bus bar 1130. It is assumed that electrical insulation is ensured among the copper pipes 1111a to 1111h and 1211a to 1211h, the copper bus bars 1112a to 1112h and 1212a to 1212h, and the copper bus bar 1130, excluding the portions connected to other members (this also applies to FIG. 5, which will be described later).

[0016] 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 1112 c 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, the copper bus bar 1112d, and the 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 (the negative x-axis side) 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. In addition, in the coil 1110 of the upper inductor 1100, the winding end portion (copper pipe 1111d) of the fourth turn is electrically connected to the copper bus bar 1130. In contrast, in the coil 1210 of the lower inductor 1200, the winding end portion (copper bus bar 1212h) of the fourth turn is electrically connected to the copper bus bar 1130.

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

[0024] Furthermore, the copper pipe 1211b, the copper bus bar 1212e, and the copper pipe 1211e form the third turn (same turn) of the coil 1210. The copper bus bar 1212f electrically connects the third turn and the fourth turn of the 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 illustrate an example in which the copper pipes 1111a to 1111h and 1211a to 1211h have the same size and shape. The copper pipes 1111a to 1111h and 1211a to 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 to 1111h and 1211a to 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 making the directions of the magnetic fluxes generated from the coils 1110 and 1210 approximately the same (preferably the same) at the same time due to the alternating current flowing through the coils 1110 and 1210, and by intersecting the alternating magnetic field 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 current flowing through the coils 1110 and 1210 causes 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 conductor 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 need to have a hollow region. In this case, when 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 showing 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 shown 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 shown 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 installing the coils 1110 and 1210 on the cores 1120 and 1220, it is necessary to place the copper pipes 1111a to 1111h and 1211a to 1211h, respectively, in the slots 1121a to 1211b and 1221a to 1221b of the cores 1120 and 1220. 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, among the areas of copper pipes 1111a to 1111h and 1211a to 1211h, the areas to which copper bus bars 1112a to 1112h and 1212a to 1212h are attached are disposed outside slots 1121a to 1211b and 1221a to 1221b, respectively.

[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 trunk 1125, a boundary line 1126b between the second leg 1123 and the trunk 1125, and a boundary line 1126c between the third leg 1124 and the trunk 1125 for the core 1120. Similarly, as imaginary lines, a boundary line 1226a between the first leg 1222 and the trunk 1225, a boundary line 1226b between the second leg 1223 and the trunk 1225, and a boundary line 1226c between the third leg 1224 and the trunk 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 where 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 where 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 a case in which the body 1125 is positioned closer to the rear surface than the first leg 1122, the second leg 1123, and the third leg 1124. The rear surface is the side opposite 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 a case in which the base end surfaces (end surfaces opposite the conductive plate M) of the first leg 1122, the second leg 1123, and the third leg 1124 are seamlessly connected to the body 1125. The base end surfaces of the first leg 1122, the second leg 1123, and the third leg 1124 are end surfaces 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 magnetic connection between first leg 1122, second leg 1123, and third leg 1124 and body 1125 means that the same main magnetic flux flows through first leg 1122, second leg 1123, and third leg 1124 and body 1125. The main magnetic flux is magnetic flux that contributes to heating conductor plate M. For example, the main magnetic flux flows in a closed circuit (magnetic path) that passes through core 1120 of upper inductor 1100, conductor plate M, and core 1220 of lower inductor 1200.

[0038] Figure 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 the core 1220, an example is shown in which the trunk 1225 is disposed closer to the rear side than the first leg 1222, the second leg 1223, and the third leg 1224. Specifically, Figure 4 illustrates an example in which the base end surfaces of the first leg 1222, the second leg 1223, and the third leg 1224 are connected seamlessly to the trunk 1225. Note that the base end surfaces of the first leg 1222, the second leg 1223, and the third leg 1224 are end surfaces on the negative side of the z-axis. Therefore, the first leg 1222, the second leg 1223, and the third leg 1224 are magnetically connected to the trunk 1225.

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

[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. Therefore, no boundary lines exist 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 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 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 the coil is 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 (y-axis 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 increased, 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 to 1111h and 1211a to 1211h electrically connected to each other. In the examples shown in Figures 1 and 3, the copper pipes 1111a to 1111h and 1211a to 1211h are examples of conductors. Note that the conductors may be made of conductors other than copper. Furthermore, the conductors do not have to be pipes.

[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 (A) below 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) The first copper pipes 1111a to 1111c, 1111d to 1111f, 1211a to 1211c, 1211d to 1211f are copper pipes that are positioned 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 plate thickness direction (z-axis direction) of the conductor plate M, the copper pipe (e.g., copper pipe 1111b) among the multiple copper pipes that is located closest to the conductor plate M is the first copper pipe.

[0049] On the other hand, when there is only one copper pipe in one slot 1121a, 1121b, 1221a, or 1221b at each position (each y coordinate) in the heating longitudinal direction (y-axis direction), that copper pipe (e.g., copper pipe 1111a or 1111c) is the first copper pipe. 1 and 3 illustrate examples in which 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 to 1111f, 1211a to 1211f. In the following description, such a copper pipe will be referred to as a second copper pipe as necessary. 1 and 3 illustrate the case where the copper pipes 1111g to 1111h and 1211g to 1211h are second copper pipes.

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

[0052] 1 and 3, the first copper pipes 1111a to 1111f and 1211a to 1211f are examples of first conductors, and the second copper pipes 1111g to 1111h and 1211g to 1211h are examples of second conductors.

[0053] In one 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 form the third turn of the coil 1210, and the second copper pipes 1211g and 1211h form the second turn of the coil 1210. Therefore, the first copper pipes 1211b and 1211e and the second copper pipes 1211g and 1211h form different turns 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 coils 1110, 1210 can be increased as long as the current density of copper pipes 1111a to 1111h, 1211a to 1211h constituting coils 1110, 1210 does not exceed the current density allowed for those copper pipes. Thus, induction heating device 1000 can be configured to have the heating capacity necessary to heat conductor plate M while preventing the length of 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 to 1111f and 1211a to 1211f have different turns in each slot 1121a, 1121b, 1221a, and 1221b. This is because it is possible to increase the number of turns N of the coils 1110 and 1210 while preventing the induction heating device 1000 from becoming longer in the heating longitudinal direction (y-axis direction).

[0058] Furthermore, when configuring induction heating device 1000 in this manner, it is preferable to arrange multiple copper pipes 1111a to 1111c, 1111d to 1111f, 1211a to 1211c, and 1211d to 1211f in the heating longitudinal 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 the 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 convenience 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 the conductor plate M). Therefore, it is preferable that the copper pipes 1111a to 1111h and 1211a to 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 material) may be placed in the high magnetic flux density region HB.

[0061] When the copper pipes 1111a-1111h and 1211a-1211h are not to be positioned in the high magnetic flux density region HB, it is preferable to position the first copper pipes 1111c, 1111d, 1211c, and 1211d in each slot 1121a, 1121b, 1221a, and 1221b farther from the conductor plate M than the high-density region HB so that their positions (y coordinates) in the heating longitudinal direction (y-axis direction) overlap at least partially with the high-density region HB. Positioning the first copper pipes 1111c, 1111d, 1211c, and 1211d in such positions reduces the number of copper pipes positioned in the heating longitudinal direction (y-axis direction). This reduces the length of the induction heating device in the heating longitudinal direction.

[0062] When the cores 1120, 1220 are so-called E-shaped cores as shown in Figures 1 and 4, in order to prevent the copper pipes 1111a to 1111h, 1211a to 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 the cores 1120, 1220, the first copper pipes 1111c, 1111d, 1211c, 1211d positioned closest to the first leg portions 1122, 1222 of the cores 1120, 1220 are positioned farther from the conductor plate M than the tip surfaces of the first legs 1122, 1222 (the end surfaces facing the conductor plate M with a gap therebetween).

[0063] In the following description, the first copper pipes arranged at positions farther from the conductor plate M than the high-density region HB and at least partially overlapping the high-density region HB in the heating longitudinal direction (y-axis direction) (y-coordinate) will be referred to as "retracted first copper pipes" as necessary. Figures 1 and 3 illustrate examples in which copper pipes 1111c, 1111d, 1211c, and 1211d are 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 to 1111b, 1111e to 1111f, 1211a to 1211b, 1211e to 1211f are located closer to the conductor plate M than the retracted first copper pipes 1111c, 1111d, 1211c, 1211d.

[0065] Furthermore, if the copper pipes 1111a to 1111h and 1211a to 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, and 1211d in each slot 1121a, 1121b, 1221a, and 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 thickness direction (z-axis direction) of the conductor plate M differs (varies) 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 each slot 1121a, 1121b, 1221a, 1221b, the number of copper pipes aligned in the thickness direction (z-axis direction) of the conductor plate M is smallest at the position (y-coordinate) where the position 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). Note that the position where the position in the heating longitudinal direction (y-axis direction) overlaps with the high magnetic flux density region HB is the position where the first retreated 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 conductor plate M is 1 (minimum) at the position (y-coordinate) in the heating longitudinal direction (y-axis direction) where it overlaps with the high magnetic flux density region HB (the 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 conductor 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 conductor 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 conductor 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 straight line that passes through the centroid position of the 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 conductor plate M and extends in the thickness direction (z-axis direction) of the conductor 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 the reference axis as the axis of symmetry. In addition, the cross section (y-z 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 Figures 1, 3, and 4, the shapes defined by the contours of slots 1121a, 1121b, 1221a, and 1221b that appear in a cross section (y-z cross section) taken perpendicular to the width direction (x-axis direction) of conductive plate M are rectangles 1127a, 1127b, 1227a, and 1127b, respectively (see Figure 1). For convenience of notation, in Figure 1, the imaginary lines representing rectangles 1127a, 1127b, 1227a, and 1127b are shown outside the actual contours of slots 1121a, 1121b, 1221a, and 1221b, respectively (this also applies to Figure 2, which will be described later). Of the contours of slots 1121a, 1121b, 1221a, and 1221b, the contours of the portions that open toward conductive plate M do not actually exist (this also applies to Figure 2, which will be described later). Furthermore, among the contour lines of the slots 1121a, 1121b, 1221a, and 1221b, the contour line of the portion that opens toward the conductive plate M is, for example, a straight line 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., the second leg 1123 and the third leg 1124 that sandwich the slot 1121a) that are located on the metal plate M side and on the slot side.

[0074] Straight lines 1129a, 1129b, 1229a, and 1229b that pass through the centroid positions 1128a, 1128b, 1228a, and 1228b of the rectangles 1127a, 1127b, 1227a, and 1227b and extend in the thickness direction (z-axis direction) of the conductor plate M are the axes of symmetry for each of the slots 1121a, 1121b, 1221a, and 1221b. Note that the 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 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 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 described 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, coils 2110 and 2210 have N turns (N is an integer equal to or greater than 2). As described above, coils 2110 and 2210 of induction heating device 2000 shown in Fig. 2 have an odd number of turns. Fig. 2 illustrates an example in which the number of turns N of coils 2110 and 2210 is 5. In an example described below with reference to Fig. 5, coils 2110 and 2210 are connected in series. In this case, the total number of turns of coils 2110 and 2210 in induction heating device 2000 is 10 (= 2 x 5). On the other hand, when coils 2110 and 2210 are connected in parallel, the total number of turns of coils 1110 and 1210 in induction heating device 1000 is 5.

[0080] FIG. 5 is a diagram showing an example of the configuration of coils 2110 and 2210. Coils 2110 and 2210 include copper pipes 2111a to 2111j and 2211a to 2211j, and copper bus bars 2112a to 2112j and 2212a to 2212j. FIG. 5 illustrates an example in which induction heating device 1000 includes copper bus bar 2130. FIG. 5 also illustrates an example in which coils 2110 and 2210 are connected in series by copper bus bar 2130. As in FIG. 3, arrows shown inside copper pipes 2111a to 2111j and 2211a to 2211j, copper bus bars 2112a to 2112j and 2212a to 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 copper pipes 2111a to 2111j and 2211a to 2211j, copper bus bars 2112a to 2112j and 2212a to 2212j, and 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 2112 c 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 (negative side of the x-axis) of copper pipe 2111a. One end of copper bus bar 2112d is electrically connected to the other end (positive side of the x-axis) of copper pipe 2111a. The other end of copper bus bar 2112d is electrically connected to one end (positive side of the x-axis) of copper pipe 2111f. One end of copper bus bar 2112e is electrically connected to the other end (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 electrically connects the second and third turns of coil 2110.

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

[0085] The other end of copper bus bar 2112g is electrically connected to one end (negative side of the x-axis) of copper pipe 2111b. One end of copper bus bar 2112h is electrically connected to the other end (positive side of the x-axis) of copper pipe 2111b. The other end of copper bus bar 2112h is electrically connected to one end (positive side of the x-axis) of copper pipe 2111e. One end of copper bus bar 2112i is electrically connected to the other end (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 electrically connects the fourth turn and fifth turn of coil 2110.

[0086] The other end of copper bus bar 2112i is electrically connected to one end (negative side of the x-axis) of copper pipe 2111c. One end of copper bus bar 2112j is electrically connected to the other end (positive side of the x-axis) of copper pipe 2111c. The other end of copper bus bar 2112j is electrically connected to one end (positive side of the x-axis) of copper pipe 2111d. One end of copper bus bar 2130 is electrically connected to the other end (negative side of the x-axis) of copper pipe 2111d. As described above, the fifth turn (same turn) of coil 2110 is formed using copper pipe 2111c, copper bus bar 2112j, and copper pipe 2111d. As described above, copper bus bar 2130 is used to connect coils 2110 and 2210 (the fifth turn of coil 1110 and the first turn of coil 2210) in series. The other end of copper bus bar 2130 is electrically connected to one end side (the negative side of the x-axis) of copper pipe 2221a of coil 2210.

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

[0088] Except for these points, the electrical connection relationship between copper pipes 2211a to 2211j and copper bus bars 2212a to 2212j of coil 2210 in lower inductor 2200 is similar to the electrical connection relationship between copper pipes 2111a to 2111j and copper bus bars 2112a to 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 to 2211j and copper bus bars 2212a to 2212j used to form each turn, and a description of the specific connection relationship between copper pipes 2211a to 2211j and copper bus bars 2212a to 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 electrically connects the second and third turns of coil 2210.

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

[0092] Furthermore, the copper pipe 2211h, the copper bus bar 2212g, and the copper pipe 2211i form the fourth turn (same turn) of the coil 2210. The copper bus bar 2212h is used 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 the other end 5002 of AC power supply 5000.

[0094] 2 and 5 illustrate 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 (e.g., cooling water) is supplied to the hollow parts of the copper pipes 2111a to 2111j and 2211a to 2211j.

[0095] As in Figure 3, Figure 5 also illustrates a case in which coils 2110 and 2210 are connected in series, thereby causing the alternating current flowing through coils 2110 and 2210 to cause the magnetic flux generated from coils 2110 and 2210 to have approximately the same (preferably the same) direction at the same time, and causing an alternating magnetic field to intersect approximately perpendicular (preferably perpendicular) to the plate surface of conductor plate M, thereby inductively heating 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 conductor 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 coils 2110 and 2210 are connected in parallel, for example, copper bus bar 2130 is not necessary. Instead, one end (negative side of the x-axis) of copper pipe 2211a of coil 2210 is connected to one end 5001 of AC power supply 5000 via copper bus bar 2112a or the like. Furthermore, the other end (negative side of the x-axis) of copper pipe 2111d of coil 1110 is connected to the other end 5002 of AC power supply 5000. The other end (negative side of the x-axis) of copper pipe 2111d of coil 1110 may be connected to the 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 in which, of two copper pipes 2211a and 2211g, and two copper pipes 2211e and 2211i arranged in the thickness direction (z-axis direction) of the conductor plate M in the coil 2210, the copper pipes 2211a and 2211e, which are located closer to the conductor plate M, are wound first. Specifically, a case is illustrated in which the copper pipe 2211a is wound in the first turn, while the copper pipe 2211g is wound in the second turn. Also, a case is illustrated in which the copper pipe 2211e is wound in the third turn, while the copper pipe 2211i is wound in the fourth turn. 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 farther 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 to 2112j and 2212a to 2212j are attached to the copper pipes 2111a to 2111j and 2211a to 2211j, respectively, avoiding the areas of the copper pipes 2111a to 2111j and 2211a to 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 to 2111j and 2211a to 2211j electrically connected to each other. In the example shown in Figures 2 and 5, the copper pipes 2111a to 2111j and 2211a to 2211j are examples of conductors. At least two of the copper pipes 2111a to 2111j and 2211a to 2211j are placed in one of the slots 1121a, 1121b, 1221a, and 1221b, respectively.

[0101] At least one of the first copper pipes 2111a to 2111f, 2211a to 2211c to 2211f is arranged in each of the slots 1121a, 1121b, 1221a, and 1221b.

[0102] Furthermore, at least one second copper pipe 2111g to 2111h, 2111i to 2111j, 2211g to 2211h, 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 examples of first conductors, and the second copper pipes 2111g to 2111h, 2111i to 2111j, 2211g to 2211h and 2211i to 2211j are examples of second conductors.

[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 respectively form different turns in the coils 2110, 2210.

[0105] For example, as described above, the first copper pipes 2111a and 2111f form the second turn of the coil 2110, and the second copper pipes 2111g and 2111j form the first turn of the coil 2110. Therefore, the first copper pipes 2111a and 2111f and the second copper pipes 2111g and 2111jf form different turns in the coil 2110. In this case, the first copper pipes 2111a and 2111f and the second copper pipes 2111g and 2111jf 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 each constitute a different turn 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 to 2111f and 2211a to 2211f have different turns in each slot 1121a, 1121b, 1221a, and 1221b.It is also preferable that the second copper pipes 2111g to 2111h, 2111i to 2111j, 2211g to 2211h, and 2211i to 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 to avoid placing the copper pipes 2111a to 2111j and 2211a to 2211j in the high magnetic flux density region HB. When avoiding placing the copper pipes 2111a to 2111j and 2211a to 2211j in the high magnetic flux density region HB, it is preferable to place the first retracted copper pipes 2111c, 2111d, 2211c, and 2211d in one slot 1121a, 1121b, 1221a, and 1221b at a position farther from the conductor plate M than the high magnetic flux density region HB so that their positions (y coordinates) in the heating longitudinal direction (y-axis direction) overlap at least partially with the high magnetic flux 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 to 2111j, 2211a to 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, retracted first copper pipes 2111c, 2111d, 2211c, 2211d positioned closest to first leg portions 1122, 1222 of cores 1120, 1220 be 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 to 2111b, 2111e to 2111f, 2211a to 2211b, 2211e to 2211f are located closer to the conductor plate M than the retracted first copper pipes 2111c, 2111d, 2211c, 2211d.

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

[0113] 2, 4, and 5, in each slot 1121a, the number of first 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 each slot 1121a, the number of first 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 each slot 1121a, the number of first 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 the above-mentioned (b), 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 longitudinal direction (y-axis direction) where it overlaps with the high magnetic flux density region HB (the 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 conductor 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 (y-z 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 the centroid positions 2128a, 2128b, 2228a, and 2228b of the rectangles 2127a, 2127b, 2227a, and 2227b and extend in the thickness direction (z-axis direction) of the conductor plate M are the axes of symmetry for one slot 1121a, 1121b, 1221a, and 1221b, respectively. Note that the 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 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 to 1111h, 1211a to 1211h, 2111a to 2111j, 2211a to 2211j and the cores 1120, 1220 will be described, which is for configuring an induction heating device so that it has the heating capacity necessary 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). To simplify the explanation, a case will be described here in which the copper pipes 1111a to 1111h, 1211a to 1211h, 2111a to 2111j, 2211a to 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, the copper pipe must be designed taking into consideration the following four points: - 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 (for example, cooling water) that can be passed through the hollow part of the copper pipe and the structure of the copper pipe - The relationship between the structure of the copper pipe and the depth and width of the slot in the core (length in the heating length direction (y-axis direction)) - The relationship between the width of the slot in the core and the gap between the coils of the upper inductor and the coils of the lower inductor

[0122] Here, as shown in FIGS. 1 and 2, the widths of the copper pipes 1111a to 1111h, 1211a to 1211h, 2111a to 2111j, and 2211a to 2211j (lengths in the heating longitudinal direction (y-axis direction)) are defined as D １ The height of the copper pipes 1111a to 1111h, 1211a to 1211h, 2111a to 2111j, and 2211a to 2211j (the length in the thickness direction (z-axis direction) of the conductor plate M) is D ２ The width of the slots 1121a, 1121b, 1221a, and 1221b is K (mm). １ The depth of the slots 1121a, 1121b, 1221a, and 1221b is K (mm). ２ (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 formula (1): δ = 503.3 × {ρ ÷ (μ ｒ ×f)} ０．５ x10 ３ ... (1) where ρ is the resistivity of the conductor that constitutes the coil (×10 －８ μ ｒ is the relative permeability of the conductor that constitutes the coil, and f is the frequency (Hz) of the AC current flowing through the coil.

[0124] Current value I of the AC current flowing through the coil １ (A) is the current density I of the AC current determined from the cross-sectional area of ​​the coil (copper pipe) ２ (A / mm ２ ) multiplied by the cross-sectional area of ​​the coil (copper pipe) through which the AC current flows. The current density I of the AC current, which is determined from the cross-sectional area of ​​the coil (copper pipe), is ２ is the cross-sectional area of ​​the coil (copper pipe) (the area of ​​the region indicated by the solid line in FIG. 6), and the current value I of the AC current flowing through the coil １ The cross-sectional area of ​​the AC current flowing through the coil (copper pipe) is the area of ​​the gray region in Figure 6 (= δ × D １ ) Therefore, the following equation (2) holds, and by transforming equation (2), the following equation (3) is obtained. １ =D １ ×δ×I ２ ... (2) I ２ =I １ ÷(D １ × δ) ... (3)

[0125] The current density I of the AC current is determined by the cross-sectional area of ​​the conductor (copper pipe) that makes up the coil. ２ The allowable current density 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. ２ｍａｘ ≧I １ ÷(D １ × δ) (4) From equations (3) and (4), the following equation (5) is established. １ ÷(I ２ｍａｘ × δ) ≦ D １ =I １ ÷(I ２ × δ) ... (5)

[0126] According to the formula (5), the width D of the copper pipes 1111a to 1111h, 1211a to 1211h, 2111a to 2111j, and 2211a to 2211j is １ is determined. Note that the allowable current density I ２ｍａｘ is, for example, 40 A / mm ２ However, the allowable current density I ２ｍａｘ is 40A / mm ２ In addition, the allowable current density I ２ｍａｘ is, for example, 60 A / mm ２ Preferably, it is:

[0127] The volumetric flow rate of the cooling medium (e.g., cooling water) flowing through the hollow portion of the copper pipe is L (l / min). The allowable flow rate of the cooling medium is v ｍａｘ (m / s). Then, the following formula (6) must be satisfied. Note that the allowable flow velocity of the cooling medium is v ｍａｘ is determined based on the fact that the cooling performance of the copper pipe by the cooling medium is reduced due to the occurrence of cavitation, for example. ｍａｘ is, for example, 5 m / s. However, the allowable flow velocity of the cooling medium, v ｍａｘ is not limited to 5 m / s. ２ ≧L÷(v ｍａｘ x60xD １ x10 －３ ) ... (6)

[0128] In equation (6), "L ÷ (v ｍａｘ x60 x 10 －３) is the minimum area of ​​the hollow part of the copper pipe that must be secured to allow the cooling medium to flow (the area of ​​the region indicated by the dashed line in Figure 6 (mm ２ ))) From equation (6), the height D of the copper pipes 1111a to 1111h, 1211a to 1211h, 2111a to 2111j, and 2211a to 2211j is ２ In addition, in FIG. 1 and FIG. 2, the width D of the copper pipes 1111a to 1111h, 1211a to 1211h, 2111a to 2111j, and 2211a to 2211j is determined. １ However, the height D of the copper pipes 1111a to 1111h, 1211a to 1211h, 2111a to 2111j, and 2211a to 2211j ２ However, this is not necessarily the case. The former may be shorter than the latter, or the former and the latter may be the same (i.e., D １ <D ２ But that's fine, D １ =D ２ But that's fine.)

[0129] Transforming equation (6) gives the following equation (7): L÷(v ｍａｘ x60 x 10 －３ ) ≦D １ ×D ２ In equation (6), it is assumed that the penetration depth δ is small (i.e., the area of ​​the hollow rectangular region indicated by the solid diagonal lines in FIG. 6 is 0 (zero)), and as shown in equation (7), the minimum area of ​​the hollow part of the copper pipe that must be secured to allow the cooling medium to flow (= L ÷ (v ｍａｘ x60 x 10 －３ )) is the area of ​​the rectangular region indicated by the solid and dashed diagonal lines in FIG. １ ×D ２ However, the height D of the copper pipes 1111a to 1111h, 1211a to 1211h, 2111a to 2111j, and 2211a to 2211j is ２ In order to determine more accurately, "D" in Eq. (7) １ ×D ２ ", the area (mm ) of the rectangular region indicated by the dashed diagonal lines in FIG. 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 x I １ ) ２ ...(8a) P=(N×I １ ) ２ ...(8b) Formula (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. Formula (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. １ However, the width D of the copper pipe １ If the width D of the copper pipe is shortened to an extremely short value, the equations (5) and (6) can be satisfied. １ and height D ２ Therefore, as described above in the sections (induction heating device 1000) and (induction heating device 2000), if the second copper pipe is 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, the heating capacity of the induction heating device can be increased without increasing the width of the copper pipe. Specifically, the depth K of the slots 1121a, 1121b, 1221a, and 1221b is determined so as to satisfy the following formula (9): ２ By determining K, at least one second copper pipe can be disposed at a position 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). ２ ≧2×D ２...(9) From equation (9), the depth K of the slots 1121a, 1121b, 1221a, and 1221b is ２ is determined.

[0132] Furthermore, when the number of turns N of the coil is an odd number (N≧3), the following formula (10a) holds. Furthermore, when the number of turns N of the coil is an even number (N≧2), the following formula (10b) holds. K １ ≧D １ ×{0.5×(N+1)} ... (10a) K １ ≧D １ ×(0.5×N+1) (10b) From equations (10a) and (10b), the width K of the slots 1121a, 1121b, 1221a, and 1221b is calculated. １ is determined.

[0133] 1 and 3 illustrate an example in which the number of turns N of coils 2110, 2210 is 4. Also, in FIGS. 2 and 5, 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 any number equal to or greater than 2. 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 the copper pipes 1111c-1111d, 1211c-1211d, 2111c-2111d, 2211c-2211d, which are located closest to the first legs 1122, 1222 of the cores 1120, 1220, are located farther from the conductor plate M than the tip faces (end faces facing the conductor plate M with a gap) of the first legs 1122, 1222. The inventors have found, from the results of electromagnetic field analysis of the induction heating device and other factors, that it is even more preferable to satisfy the following formula (11): d≧K ２ ÷5 ... (11)

[0135] 1 and 2, d (mm) is the distance in the plate thickness direction (z-axis direction) of the conductor plate M between the surfaces of the retracted first copper pipes 1111c, 1111d, 1211c, 1211d, 2111c, 2111d, 2211c, and 2211d on the conductor plate M side 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 plate thickness direction (z-axis direction) of the conductor plate M between the first conductor part (e.g., the retracted first copper pipe 1111c) arranged at a position closest to the first leg of the core (e.g., the first leg 1122) and the tip face of the first leg is equal to the depth of the slot (e.g., the depth K of the slot 1121a). ２ ) or more.

[0136] (Modification) Next, a modification of this embodiment will be described. In this embodiment, as shown in FIGS. 1 and 2, in one slot 1121a, 1121b, 1221a, or 1221b, the maximum number of rows of copper pipes 1111a-1111h, 1211a-1211h, 2111a-2111j, or 2211a-2211j in the thickness direction (z-axis direction) of the conductor plate M is two. However, in one slot of the core, the maximum number of rows of copper pipes 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. Fig. 7 illustrates a case where the maximum number of copper pipes 7111a to 7111p and 7211a to 7111p arranged in one slot of the cores 7120 and 7220 in the thickness direction (z-axis direction) of the conductor plate M is three.

[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. Figure 7 illustrates an example in which the maximum number of such second copper pipes is 2 (see second copper pipes 7111g to 7111h, 7111i to 7111j, 7111m to 7111n, 7111o to 7111p, 7111g to 7111h, 7211i to 7211j, 7211m to 7211n, 7211o to 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 1111c, 1111d, 1211c, 1211d, 2111c, 2111d, 2211c, and 2211d. 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. Figure 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 and 1211g-1211h are arranged so that the entire y-coordinates (positions) of the second copper pipes 1111b, 1111e, 1211b, 1211e, 2111a-2211b, 2111e-2111f, 2211a-2211b, and 2211e-2211f overlap with the first copper pipe. However, the second copper pipes may be arranged so that the entire y-coordinates (positions) of the second copper pipes overlap with the first copper pipe. Figure 8 shows an example of the configuration of an induction heating device 8000 in this case. Similar to Figures 1 and 2, Figure 8 shows a cross section of the conductor plate M taken perpendicular to the width direction (x-axis direction). 8, induction heating device 8000 has an upper inductor 8100 and a lower inductor 8200. Upper inductor 8100 and lower inductor 8200 have coils 8110 and 8210 and cores 1120 and 1220, respectively. In induction heating device 8000 shown in Fig. 8, the positions of second copper pipes 1111g, 1111h, 1211g, and 1221h of induction heating device 1000 shown in Fig. 1 are changed. Figure 8 illustrates an example in which second copper pipes 1111g, 1111h, 1211g, and 1221h are arranged so that their positions (y coordinates) in the heating longitudinal direction (y-axis direction) overlap with those of one first copper pipe 1111a-1111b, 1111e-1111f, 1211a-1211b, and 1211e-1211f.

[0140] In this embodiment, the case where the retreated first copper pipes 1111c, 1111d, 1211c, 1221d, 2111c, 2111d, 2211c, and 2221d in one slot 1121a, 1121b, 1221a, and 1221b are located farther from the conductor plate M than the other first copper pipes 1111a to 1111b, 1111e to 1111f, 1211a to 1211b, 1211e to 1211f, 2111a to 2111b, 2111e to 2111f, 2211a to 2211b, and 2211e to 2211f, respectively, is illustrated. 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 the conductor plate M. In FIG. 9, induction heating device 9000 has an upper inductor 9100 and a lower inductor 9200. Upper inductor 9100 and lower inductor 9200 have coils 9110 and 9210 and cores 9120 and 9220, respectively. In the 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 slot depths of cores 9120 and 9220 are deepened. 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 to 1111b, 1111e to 1111f, 1211a to 1211b, and 1211e to 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 to 1111f and 1211a to 1211f are disposed farther from the conductor plate M than the tip surfaces (end surfaces 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 to 1111f and 1211a to 1211f and the second copper pipes 1111g to 1111h and 1211g to 1211h respectively form different turns in one slot 1121a, 1121b, 1221a, 1221b. That is, in the present embodiment, all of the first copper pipes 1111a to 1111f and 1211a to 1211f arranged in one slot 1121a, 1121b, 1221a, 1221b form different turns from all of the second copper pipes 1111g to 1111h and 1211g to 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 that is 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 longitudinal direction (y-axis direction). However, this is not necessarily required as long as at least one first copper pipe and one second copper pipe that form different turns in the coils 1110, 1210, 2110, and 2210 are present in each slot 1121a, 1121b, 1221a, and 1221b. In other words, it is sufficient that at least one first copper pipe placed in each slot 1121a, 1121b, 1221a, and 1221b is connected in series with the second copper pipe placed 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 longitudinal 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 are identical in size and shape in each slot 1121a, 1121b, 1221a, 1221b. However, this is not necessarily the case. For example, in each slot 1121a, 1121b, 1221a, 1221b, the copper pipes other than the retreated first copper pipe may be shorter in the thickness direction (z-axis direction) of the conductor plate M than the retreated first copper pipe. Furthermore, in this state, the end face of the retreated 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 slot depth to be shallower than, for example, the case illustrated in FIG. 9.

[0144] Furthermore, in this embodiment, the cores 1120 and 1220 have three legs (so-called E-shaped cores). However, the number of legs of the core is not limited to three. The number of legs of the core may be two, four, or more. When separate coils are arranged on multiple legs of the core, it is preferable that all of the coils have the first copper pipe and the second copper pipe determined as described above. This is because, compared to a case where this is not done, it is possible to achieve a larger number of coil turns N for the coils arranged on all legs while suppressing an increase in the length of the induction heating device in the heating longitudinal direction (y-axis direction). However, it is sufficient that at least one pair of coils located 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 a case where this is not done, it is possible to increase the number of coil turns N while suppressing an increase in the length of the induction heating device in the heating longitudinal direction (y-axis direction).

[0145] (Other Embodiments) 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.

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

Claims

1. The inductor has an upper inductor and a lower inductor that are 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 on 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 a conductor portion 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 of the slots, at least a portion of a position of at least one of the first conductor portions in the heating longitudinal direction and at least a portion of a position of at least one of the second conductor portions in the heating longitudinal direction overlap with each other; The heating length direction is a direction parallel to the conveying direction of the conductor plate, A transverse type induction heating device, wherein one of the slots has at least one second conductor portion electrically connected in series to the first conductor portion.

2. 2. The transverse type induction heating device according to claim 1, wherein the conductor portion is not disposed in an area of ​​the slot in which the conductor portion is disposed that has the highest magnetic flux density when the core is excited by an alternating current flowing through the coil.

3. 3. The transverse type induction heating device according to claim 2, 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 length direction overlaps with the region with the highest magnetic flux density.

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

5. 5. A transverse type induction heating device as described in claim 4, wherein the distance in the plate 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.

6. The transverse type induction heating device according to any one of claims 1 to 3, wherein a plurality of the conductor portions are arranged in the heating length direction in one slot.