Transverse induction heating device

Abstract

Coils (220, 320) are disposed respectively on a front side and a rear side of a conveying-planned plane (CP). Non-edge cores (211,311) and edge cores (212-213, 312-313) are disposed facing the coils (220, 320). The non-edge cores (211, 311) are so-called T-shaped cores and are disposed in a central region in an x-axis direction. The two edge cores (212-213, 312-313) are so-called E-shaped cores, and are disposed on both sides, in the x-axis direction, of the non-edge cores (211, 311) respectively. A distance between upstream side leg portions (2122, 3122) and downstream side leg portions (2123, 3123) of the edge cores (212, 313) and the conveying-planned plane (CP) is less than a distance between parts of the non-edge cores (211, 311) other than central leg portions (2111, 3111) thereof and the conveying-planned plane (CP).

Description

Technical Field

[0001] The present invention relates to a transverse induction heating device, and in particular, it is suitable for use in inducing heating of a conductor plate to be heated by intersecting an alternating magnetic field with the plate surface of the conductor plate. This application claims priority based on Japanese Patent Application No. 2021-142296 filed in Japan on September 1, 2021, and incorporates all of its contents herein by reference.

Background Art

[0002] A conductor plate such as a strip steel plate is continuously heated using an induction heating device. The induction heating device applies an alternating magnetic field generated from a coil to the conductor plate. Then, eddy currents are induced in the conductor plate by electromagnetic induction. The conductor plate is heated by the Joule heat based on these eddy currents. As an induction heating device, there is a solenoid type induction heating device. The solenoid type induction heating device applies an alternating magnetic field substantially parallel to the longitudinal direction of the conductor plate placed inside the solenoid coil. When the thickness of the conductor plate to be heated becomes thin (for example, when the thickness of the conductor plate becomes 1 mm or less), in the solenoid type induction heating device, there is a risk that the conductor plate cannot be heated to a desired temperature even if the frequency of the alternating magnetic field is increased.

[0003] As an induction heating device capable of easily inducing heating of a thin conductor plate, there is a transverse induction heating device. The transverse induction heating device includes, for example, a pair of coils arranged on the front side and the back side of the planned conveyance surface of the conductor plate conveyed in the horizontal direction. The coils constituting the pair of coils are arranged such that the alternating magnetic fields generated by energizing alternating current in the same direction cross the planned conveyance surface of the conductor plate. In a general transverse induction heating device, eddy currents concentrate at the ends in the width direction of the conductor plate. For this reason, the current density at the ends in the width direction of the conductor plate increases. Then, there is a risk that the ends in the width direction of the conductor plate may be overheated. Note that the width direction is a direction perpendicular to the conveyance direction of the conductor plate and the facing direction of the coils. In the following description, the ends in the width direction of the conductor plate are referred to as edge portions as needed.

[0004] In response to such problems, Patent Document 1 discloses arranging a shield plate (shielding plate) movable in the width direction between the edge portion of the conductor plate and the magnetic pole. The shield plate is made of a non-magnetic metal material. In such a technique, by shielding the alternating magnetic field generated from the coil with the shield plate, it is possible to suppress the non-uniformity of the temperature distribution in the width direction of the conductor.

[0005] Also, Patent Document 2 discloses arranging a secondary coil for generating a magnetic field that cancels out the alternating magnetic field generated from the coil for heating the conductor plate between the edge portion of the conductor plate and the magnetic pole. In the technique described in Patent Document 2, by generating a magnetic field that cancels out the alternating magnetic field generated from the coil from the secondary coil, it is possible to suppress the non-uniformity of the temperature distribution in the width direction of the conductor.

[0006] Also, Patent Document 3 discloses forming a bulging portion with respect to the original core. The bulging portion is arranged at a position facing the regions where the temperature decreases at both ends in the width direction in the region of the conductor plate. In the technique described in Patent Document 3, the bulging portion formed with respect to the original core suppresses the non-uniformity of the temperature distribution in the width direction of the conductor.

[0007] In addition, Patent Document 4 discloses a technique for constructing a coil using a first J-shaped conductor 32 and a second J-shaped conductor 34. In the technique described in Patent Document 4, by moving the first J-shaped conductor 32 in the width direction with respect to the second J-shaped conductor 34, the length in the width direction of the region between the first J-shaped conductor 32 and the second J-shaped conductor 34 is changed. In the technique described in Patent Document 4, by changing the length in the width direction of the region between the first J-shaped conductor 32 and the second J-shaped conductor 34 in accordance with the width of the conductor, it is possible to suppress the non-uniformity of the temperature distribution in the width direction of the conductor.

[0008] In addition, Patent Document 5 discloses a technique for arranging a plurality of magnetic pole segments in the width direction. In such a technique, by changing the distance between the plurality of magnetic pole segments and the conductor in accordance with the width of the conductor, it is possible to suppress the non-uniformity of the temperature distribution in the width direction of the conductor. Patent Document 5 also discloses a technique for arranging a plurality of bar-shaped magnets around which a coil is wound at intervals along the conveyance direction of the conductor. In such a technique, the plurality of bar-shaped magnets rotate about an axis that passes through the position of the center of gravity of each magnet and extends in a direction perpendicular to the conductor. In such a technique, by rotating the plurality of bar-shaped magnets in accordance with the width of the conductor, it is possible to suppress the non-uniformity of the temperature distribution in the width direction of the conductor. Patent Document 5 also discloses arranging a plurality of iron cores in the conveyance direction of the conductor and switching the current flowing through the coil wound around the iron core. In such a technique, by switching the current flowing through the coil wound around the iron core in accordance with the width of the conductor, the iron core that generates magnetic flux is switched. In such a technique, by doing so, it is possible to suppress the non-uniformity of the temperature distribution in the width direction of the conductor.

[0009] In addition, Patent Document 6 discloses a technique using a plurality of magnetic bars arranged in the width direction of a conductor as a core. In the technique described in Patent Document 6, by adjusting the intervals between the plurality of magnetic bars according to the width of the conductor and using a shield plate, it is possible to suppress the non-uniformity of the temperature distribution in the width direction of the conductor.

[0010] However, in the techniques described in Patent Documents 1 to 3 and 5 to 6, a plurality of magnetic poles are arranged at intervals in the longitudinal direction (transport direction) of the conductor. Therefore, in the techniques described in Patent Documents 1 to 3 and 5 to 6, an alternating magnetic field that does not point from each magnetic pole toward the conductor but toward a plurality of other magnetic poles is included. Thus, there is a risk that an alternating magnetic field of a desired magnitude cannot be applied to the strip-shaped conductor. As a result, there is a risk that the heating efficiency of the conductor will decrease. Further, in the technique described in Patent Document 4, the core does not have legs (teeth). Therefore, also in the technique described in Patent Document 4, there is a risk that an alternating magnetic field of a desired magnitude cannot be applied to the strip-shaped conductor. Thus, the heating efficiency of the strip-shaped conductor decreases.

[0011] On the other hand, Patent Document 7 discloses a technique in which the tip of the leg (tooth) of a so-called T-shaped core is made into a sharp wedge shape. In the technique described in Patent Document 7, by forming the core into a T shape, the density of the magnetic force lines intersecting the conductor is concentrated.

Prior Art Documents

Patent Documents

[0012]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

[0013] However, in the technique described in Patent Document 7, there is one magnetic pole (the leg portion of the core). Therefore, when there is an alternating magnetic field that does not reach the conductor, there is a risk that the alternating magnetic field diffuses around without returning to the magnetic pole. Thus, there is a risk that surrounding objects (for example, electronic devices) are heated by the alternating magnetic field diffused from the core. In this case, there is a risk that conductors and magnetic bodies unrelated to the conductor to be heated are heated. Also, there is a risk that noise is generated in surrounding objects by the alternating magnetic field diffused from the core. Further, there is a risk that the conductor plate undergoes unintended heating by the alternating magnetic field diffused from the core. In this case, there is a risk that the temperature distribution in the width direction of the conductor plate becomes non-uniform.

[0014] Further, for example, with respect to the technology described in Patent Document 7, when a shield member is disposed between the edge portion of the conductor plate and the magnetic pole, the alternating magnetic field from the magnetic pole is likely to diffuse as noise to the surroundings. For example, when a shield plate is used as the shield member as described in Patent Documents 1 and 6, a large eddy current is generated in the shield plate by the alternating magnetic field from the magnetic pole. Therefore, the alternating magnetic field from the magnetic pole is likely to be repelled by the magnetic field of the eddy current generated in the shield plate. When the alternating magnetic field repelled by the shield plate does not return to the magnetic pole, the alternating magnetic field becomes a factor in heating surrounding objects and a factor in generating noise in surrounding objects. Further, when a secondary coil is used as the shield member as described in Patent Document 2, an alternating magnetic field that is not canceled by the magnetic field generated from the secondary coil and does not return to the magnetic pole may be generated from the alternating magnetic field from the magnetic pole. Such an alternating magnetic field also becomes a factor in heating surrounding objects and a factor in generating noise in surrounding objects. Further, due to the alternating magnetic field diffused as described above, the distribution of the alternating magnetic field applied to the conductor plate may change with respect to the original distribution of the alternating magnetic field determined by the arrangement of the magnetic poles. In this case, there is a risk that the conductor plate may cause unintended heating. Such unintended heating may cause the temperature distribution in the width direction of the conductor plate to become non-uniform. The places where the transverse induction heating device is installed are not under the same conditions. Therefore, it is substantially impossible to predict whether the conductor plate will cause unintended heating. If the total power of the transverse induction heating device increases due to the unintended heating of the conductor plate, there is a risk of reducing the heating efficiency of the entire transverse induction heating device. In this case, there is a risk that the method of supplying power to the transverse induction heating device may have to be reviewed in order to heat the conductor plate to a desired temperature. Note that the diffusion of the alternating magnetic field can also occur when a core without legs (teeth) is used as described in Patent Document 4, and when a plurality of cores as described in Patent Documents 5 and 6 are used.

[0015] As described above, in the conventional technology, there is a problem that it is impossible to realize an induction heating device aimed at achieving both suppression of a decrease in the magnitude of an alternating magnetic field applied to a strip-shaped conductor and suppression of diffusion of the alternating magnetic field.

[0016] The present invention has been made in view of the above problems, and an object thereof is to realize an induction heating device aimed at achieving both suppression of a decrease in the magnitude of an alternating magnetic field applied to a strip-shaped conductor and suppression of diffusion of the alternating magnetic field.

Means for Solving the Problems

[0017] A first example of the transverse induction heating device of the present invention is a transverse induction heating device comprising: a pair of coils, at least one of which is disposed on each of the front side and the back side of the planned conveyance surface of the conductor plate such that an alternating magnetic field generated by energizing an alternating current in the same direction intersects the planned conveyance surface; and cores, one set being disposed for each one of the pair of coils. The set of cores disposed for each one of the coils has a non-edge core disposed at a position including the center in the width direction, and edge cores disposed on both sides of the non-edge core in the width direction. The width direction is a direction perpendicular to the conveyance direction of the conductor plate and the facing direction of the coils. The non-edge core has a body portion and a central leg portion. Each of the edge cores disposed on both sides of the non-edge core in the width direction has a body portion, a central leg portion, an upstream leg portion, and a downstream leg portion. The body portion extends in the conveyance direction from a region upstream of the coil in the conveyance direction to a region downstream of the coil in the conveyance direction on the back side of the coil. The back side is the side opposite to the side where the planned conveyance surface exists. The central leg portion extends from the body portion toward the planned conveyance surface so as to pass through the hollow portion of the coil. The upstream leg portion extends from the body portion toward the planned conveyance surface upstream of the coil. The downstream leg portion extends from the body portion toward the planned conveyance surface downstream of the coil. The intervals between the upstream leg portion and the downstream leg portion of the edge core and the planned conveyance surface are shorter than the intervals between the portions other than the central leg portion of the non-edge core and the planned conveyance surface. The distance between the central leg portion of the non-edge core and the planned conveyance surface is shorter than the distance between the portion of the non-edge core other than the central leg portion and the planned conveyance surface, and a part of the coil is outside the edge core in the width direction. It is characterized by this. A first 2 example of the transverse induction heating device of the present invention is characterized in that the non-edge core does not have the upstream leg portion and the downstream leg portion. A first 3 example of the transverse induction heating device of the present invention is characterized in that the non-edge core has the upstream leg portion and the downstream leg portion. A first 4The example is characterized in that the distance between the central leg portion of the edge core and the planned conveyance surface is the same as the distance between the upstream leg portion and the downstream leg portion of the edge core and the planned conveyance surface. The first 5 The example is characterized in that the distance between the central leg portion of the edge core and the planned conveyance surface is the same as the distance between the central leg portion of the non-edge core and the planned conveyance surface. The first 6 The example of the pair of cores is characterized in that the non-edge core and the edge cores arranged on both sides of the non-edge core are an integral core.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Figure 25

Figure 26

Figure 27

Figure 28

Figure 29

MODE FOR CARRYING OUT THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same things include not only the cases where they are exactly the same, but also the cases where they are different within the scope not departing from the gist of the invention. Similarly, in the following description, the things that match include not only the cases where they exactly match, but also the cases where they do not match within the scope not departing from the gist of the invention. For example, in the following description, the same things include those that are different within the range of tolerances determined at the time of design (for example, within ±5%). 。 In the following description, the induction heating device of the transverse type will be referred to as an induction heating device as necessary. In the following description, the case where the conductor plate to be heated is a strip steel plate will be exemplified (however, the conductor plate to be heated is not limited to the strip steel plate). Also, for the convenience of notation and explanation, in each figure, some configurations are shown with omission or simplification. Also, the x-y-z coordinates shown in each figure indicate the relationship of directions in each figure. The symbol with a black circle (●) in a white circle (〇) indicates the direction from the back side to the front side of the paper surface.

[0020] (First Embodiment) First, a first embodiment of the present invention will be described. FIG. 1 is a diagram showing an example of the external configuration of an induction heating device. Specifically, FIG. 1 is a diagram showing the induction heating device viewed from obliquely above. In FIG. 1, a case where the strip steel sheet 100 is conveyed in the direction of the arrow (the positive direction of the y-axis) attached to the tip of the strip steel sheet 100 is illustrated. That is, in FIG. 1, a case where the conveyance direction of the strip steel sheet 100 is the positive direction of the y-axis is illustrated. Further, in FIG. 1, a case where the longitudinal direction of the strip steel sheet 100 is the y-axis direction, the width direction of the strip steel sheet 100 is the x-axis direction, and the thickness direction of the strip steel sheet 100 is the z-axis direction is illustrated. Note that the thickness of the strip steel sheet 100 is not limited. However, the induction heating device of each embodiment can heat a thin conductive plate. Therefore, the thickness of the strip steel sheet 100 to be heated by the induction heating device of each embodiment is preferably, for example, 1 mm or less. However, the thickness of the strip steel sheet 100 to be heated by the induction heating device of each embodiment may exceed 1 mm.

[0021] The induction heating device shown in FIG. 1 includes an upper inductor 200 and a lower inductor 300. The upper inductor 200 and the lower inductor 300 are arranged at positions facing each other with the strip steel sheet 100 interposed therebetween (see FIGS. 2 to 5). The upper inductor 200 and the lower inductor 300 have the same configuration. Therefore, here, the upper inductor 200 will be described in detail, and the detailed description of the lower inductor 300 will be omitted as necessary. The strip steel sheet 100 may move in the z-axis direction and the x-axis direction, and the strip steel sheet 100 may be located at a position slightly deviated from the center of the induction heating device. Even with such movement of the position of the strip steel sheet 100 (for example, meandering), the strip steel sheet 100 is often controlled to be located as close as possible to the center of the induction heating device by a known technique (for example, International Publication WO2019 / 181653). In the following figures including FIG. 1, in principle, the strip steel sheet 100 is in an ideal position (for example, located at the center of the induction heating device) where the heating amount on the upper surface side and the lower surface side of the strip steel sheet 100 and the heating amount on the left side and the right side in the conveyance direction of the strip steel sheet 100 are equal. isThe state in a certain case is illustrated. In the following description, when the strip steel plate 100 is in the above-mentioned ideal position, a plane passing through the center position in the thickness direction of the strip steel plate 100 and perpendicular to the thickness direction of the strip steel plate 100 is referred to as a planned conveyance plane CP as needed. Note that the plane passing through the center position in the thickness direction of the strip steel plate 100 and perpendicular to the thickness direction of the strip steel plate 100 is also a plane passing through the center position in the thickness direction of the strip steel plate 100 and parallel to the plate surface of the strip steel plate 100. Since the planned conveyance plane CP is determined during the design of the induction heating device, the planned conveyance plane CP is inherent in the induction heating device itself. The planned conveyance plane CP is often located at the center of the induction heating device. For this reason, the plane formed by the center of the distance between the upper inductor 200 and the lower inductor 300 may be used as the planned conveyance plane CP. In the following description, the conveyance direction of the strip steel plate 100 is referred to as the conveyance direction as needed. In the following description, the direction in which the upper inductor 200 and the lower inductor 300 face each other is referred to as the coil facing direction or simply the facing direction as needed. In FIG. 1, a case is illustrated where the front side of the planned conveyance plane CP is on the positive direction side of the z-axis and the back side of the planned conveyance plane CP is on the negative direction side of the z-axis. In FIG. 1, a case is also illustrated where the upper inductor 200 is arranged on the front side of the planned conveyance plane CP and the lower inductor 300 is arranged on the back side of the planned conveyance plane CP.

[0022] As described above, FIG. 1 illustrates a case where the coil facing direction is the z-axis direction and the conveyance direction of the strip steel plate 100 is the positive direction of the y-axis. Therefore, FIG. 1 illustrates a case where the width direction, which is the direction perpendicular to the coil facing direction and the conveyance direction of the strip steel plate 100, is the x-axis direction.

[0023] The distance between the upper inductor 200 and the planned conveyance surface CP (the distance in the z-axis direction) and the distance between the lower inductor 300 and the planned conveyance surface CP are usually equal, but they may be different from each other. In the present embodiment, a case where the induction heating device has a shape with a mirror-symmetrical relationship with the y-z plane at the center of the induction heating device in the x-axis direction as the symmetry plane is exemplified. When the distance between the upper inductor 200 and the planned conveyance surface CP and the distance between the lower inductor 300 and the planned conveyance surface CP are the same, the induction heating device has a shape with a mirror-symmetrical relationship with the planned conveyance surface CP as the symmetry plane. Note that the y-z plane is a virtual plane parallel to the y-axis and the z-axis.

[0024] FIG. 2 is a diagram showing an example of a first cross section of the induction heating device. Specifically, FIG. 2 is a cross-sectional view taken along line I-I of FIG. 1. FIG. 3 is a diagram showing an example of a second cross section of the induction heating device. Specifically, FIG. 3 is a cross-sectional view taken along line II-II of FIG. 1. FIG. 4 is a diagram showing an example of a third cross section of the induction heating device. Specifically, FIG. 4 is a cross-sectional view taken along line III-III of FIG. 1. FIG. 5 is a diagram showing an example of a fourth cross section of the induction heating device. Specifically, FIG. 5 is a cross-sectional view taken along line IV-IV of FIG. 1.

[0025] In FIG. 2, the upper inductor 200 includes an upper core 210, a coil 220, and shield plates 230a and 230b. In the following description, the width direction of the induction heating device and the strip steel plate 100 is referred to as the x-axis direction as necessary. Also, in the following description, the direction parallel to the conveyance direction of the strip steel plate 100 (the longitudinal direction of the strip steel plate 100) is referred to as the y-axis direction as necessary. Further, in the following description, the facing direction between the upper inductor 200 and the lower inductor 300 (the thickness direction of the strip steel plate 100) is referred to as the z-axis direction as necessary for explanation.

[0026] The coil 220 is a conductor having a circumferential portion. In FIG. 1, a case where a thick portion (a portion other than a straight line extending from the AC power supply 400) is the circumferential portion of the coil 220 is illustrated. The circumferential portion of the coil 220 is arranged to circumscribe the upper core 210 in a racetrack shape through the slot of the upper core 210 in the x-y plane. In the present embodiment, the coils 220 and 320 are arranged so as to face the conveyance planned surface CP. Among the coils constituting the pair of coils, the coil 220 arranged on the front side of the conveyance planned surface CP and the coil 320 arranged on the back side of the conveyance planned surface CP among the coils constituting the pair of coils face each other in the above-described coil facing direction. The x-y plane is a virtual plane parallel to the x-axis and the y-axis. The coil 220 is preferably arranged such that the direction perpendicular to the conveyance planned surface CP and the direction of the axis of the coil 220 are parallel. The axis of the coil 220 is the axis when the coil 220 is circumscribed. In the example shown in FIG. 1, the axis of the coil 220 is parallel to the z-axis.

[0027] Note that the coil 220 may have an insulator arranged around the conductor. Here, a case where the number of turns of the coil 220 is 1 is illustrated. However, the number of turns of the coil 220 may be 2 or more. The number of turns of the coils 220 and 320 is preferably the same.

[0028] In FIGS. 2 to 5, a case where the end portion of the coil 220 on the conveyance planned surface CP side (the end portion in the z-axis direction closest to the conveyance planned surface CP of the coil 220) is on the conveyance planned surface CP side rather than the end portion of the upper core 210 on the conveyance planned surface CP side (the end portion in the z-axis direction closest to the conveyance planned surface CP of the upper core 210) is illustrated. However, for example, the position in the z-axis direction of the end portion of the coil 220 on the conveyance planned surface CP side and the position in the z-axis direction of the end portion of the upper core 210 on the conveyance planned surface CP side may be the same.

[0029] The upper core 210 is formed using a ferromagnetic material. As shown in FIGS. 2 and 3, the upper core 210 has a non-edge core 211 and two edge cores 212 to 213. The edge cores 212 to 213 are arranged on both sides of the non-edge core 211 in the x-axis direction (the positive x-axis direction side and the negative x-axis direction side). In the present embodiment, a case where the position of the center of the upper core 210 in the x-axis direction is included in the positions of the non-edge core 211 in the x-axis direction is exemplified.

[0030] Further, in the present embodiment, a case where the non-edge cores 211 and the two edge cores 212 to 213 are integrated is exemplified. Therefore, there is no boundary line between the non-edge core 211 and the edge cores 212 to 213.

[0031] Further, in the present embodiment, a case where the non-edge core 211 is composed of a plurality of electromagnetic steel sheets laminated in the x-axis direction and the plurality of electromagnetic steel sheets have the same thickness and the same planar shape is exemplified. Similarly, in the present embodiment, a case where the edge cores 212 to 213 are composed of a plurality of electromagnetic steel sheets laminated in the x-axis direction and the plurality of electromagnetic steel sheets have the same thickness and the same planar shape is exemplified. Also, in the present embodiment, a case where the thickness, planar shape, and number of laminated sheets of the electromagnetic steel sheets constituting the edge cores 212 to 213 are the same is exemplified. Further, in the present embodiment, a case where the thickness of the electromagnetic steel sheets constituting the non-edge core 211 is the same as the thickness of the electromagnetic steel sheets constituting the edge cores 212 to 213 is exemplified. Also, in the present embodiment, a case where the planar shape and the number of laminated sheets of the electromagnetic steel sheets constituting the non-edge core 211 are different from the planar shape and the number of laminated sheets of the electromagnetic steel sheets constituting the edge cores 212 to 213 is exemplified. For example, when the length of the non-edge core 211 in the x-axis direction is different from the length of the edge cores 212 to 213 in the x-axis direction, the number of laminated sheets of the electromagnetic steel sheets constituting the non-edge core 211 and the number of laminated sheets of the electromagnetic steel sheets constituting the edge cores 212 to 213 will be different corresponding to the difference.

[0032] The plurality of electromagnetic steel sheets constituting each of the non-edge cores 211 and the edge cores 212 to 213 are fixed so as not to separate from each other. The method of fixing the plurality of electromagnetic steel sheets is not limited. For example, various known methods such as fixing with an adhesive, fixing by welding, fixing by caulking, and fixing using a fixing member are adopted as the method of fixing the plurality of electromagnetic steel sheets. Incidentally, the thickness of the electromagnetic steel sheets constituting the non-edge core 211 and the thickness of the electromagnetic steel sheets constituting the edge cores 212 to 213 do not necessarily have to be the same. Also, for the sake of notation, in FIGS. 2 and 3, the illustration of the boundary lines of the individual electromagnetic steel sheets is omitted.

[0033] In FIG. 4, the non-edge cores 211 and 311 have central leg portions 2111 and 3111, and body portions 2112 and 3112. Incidentally, for the sake of explanation, in FIG. 4, the central leg portions 2111 and 3111 and the body portions 2112 and 3112 are indicated by two-dot chain lines (virtual lines) (the two-dot chain lines are virtual lines in each figure). FIG. 4 exemplifies the case where the central leg portions 2111 and 3111 and the body portions 2112 and 3112 are integrated. Therefore, there are no boundary lines between the central leg portions 2111 and 3111 and the body portions 2112 and 3112. Incidentally, not only in this embodiment but also in the second, third, and fourth embodiments, the name "non-edge core" is used to emphasize the meaning of not being an edge core. non It may be named with any other name such as "center core" instead of "edge core".

[0034] The body parts 2112 and 3112 extend in a direction parallel to the conveyance direction (y-axis direction) from a region on the back side of the coils 220 and 320, which is upstream (negative y-axis direction side) of the coils 220 and 320 in the conveyance direction, to a region downstream (positive y-axis direction side) of the coils 220 and 320 in the conveyance direction, respectively, on the back side of the coils 220 and 320. The back side of the coils 220 and 320 is the side opposite to the conveyance planned surface CP side. In the examples shown in FIGS. 4 and 5, the back side of the coil 220 is the positive z-axis direction side, and the back side of the coil 320 is the negative z-axis direction side. In the following description, the upstream side in the conveyance direction may be referred to as the upstream side as necessary. Also, the downstream side in the conveyance direction may be referred to as the downstream side as necessary. Further, the side opposite to the conveyance planned surface CP side may be referred to as the back side as necessary.

[0035] The central leg parts 2111 and 3111 extend from the body parts 2112 and 3112 in the direction of the conveyance planned surface CP so as to pass through the hollow parts of the coils 220 and 320, respectively. Here, the hollow part means the inner side (not the outer side) of the loop when the coils 220 and 320 that circulate in a racetrack shape are regarded as one loop. It is preferable that the positions of the central leg parts 2111 and 3111 in the y-axis direction include the positions of the axes of the coils 220 and 320 in the y-axis direction. That is, it is preferable that there is a coordinate that overlaps with the y-coordinate of the axis of the coils 220 and 320 among the y-coordinates of the central leg parts 2111 and 3111. In the present embodiment, a case where the positions (x-y coordinates) of the centers of gravity of the central leg parts 2111 and 3111 in the x-y plane coincide with the positions (x-y coordinates) of the axes of the coils 220 and 320 in the x-y plane is exemplified.

[0036] The central leg parts 2111 and 3111 are the teeth of the core. In the present embodiment, a case where the tip surfaces of the central leg parts 2111 and 3111 are the magnetic pole surfaces of the non-edge cores 211 and 311 is exemplified. The body parts 2112 and 3112 are the yokes of the core. Note that the tip surfaces of the central leg parts 2111 and 3111 are the surfaces facing the conveyance planned surface CP.

[0037] As shown in Fig. 4, the shape of the surface parallel to the y-z plane of the non-edge cores 211 and 311 is T-shaped. That is, the non-edge cores 211 and 311 are so-called T-shaped cores. Incidentally, the shape of the tip side of the central legs 2111 and 3111 may be a tapered shape. In the following description, the cross-section cut along the y-z plane is referred to as the y-z cross-section as necessary.

[0038] In Fig. 5, the edge cores 212 and 313 have central legs 2121 and 3121, upstream legs 2122 and 3122, downstream legs 2123 and 3123, and body parts 2124 and 3124.

[0039] The body parts 2124 and 3124 are respectively extended in the direction parallel to the conveyance direction (y-axis direction) from the region on the upstream side (the positive direction side of the y-axis) of the coils 220 and 320 in the conveyance direction to the region on the downstream side (the negative direction side of the y-axis) of the coils 220 and 320 on the back side of the coils 220 and 320.

[0040] The central legs 2121 and 3121 are respectively extended from the body parts 2124 and 3124 in the direction of the planned conveyance plane CP so as to pass through the hollow portions of the coils 220 and 320.

[0041] The upstream legs 2122 and 3122 are respectively extended from the body parts 2124 and 3124 in the direction of the planned conveyance plane CP on the upstream side (the negative direction side of the y-axis) of the coils 220 and 320. The downstream legs 2123 and 3123 are respectively extended from the body parts 2124 and 3124 in the direction of the planned conveyance plane CP on the downstream side (the positive direction side of the y-axis) of the coils 220 and 320.

[0042] The central legs 2121, the upstream legs 2122, and the downstream legs 2123 are arranged at intervals in the y-axis direction. The central leg 3121, the upstream leg 3122, and the downstream leg 3123 are also arranged at intervals in the y-axis direction.

[0043] The central legs 2121, 3121, the upstream legs 2122, 3122, and the downstream legs 2123, 3123 are the teeth of the core. In this embodiment, a case is illustrated where the tip surfaces of the central legs 2121, 3121, the tip surfaces of the upstream legs 2122, 3122, and the tip surfaces of the downstream legs 2123, 3123 are the magnetic pole surfaces of the edge cores 212, 312. The body portions 2124, 3124 are the yokes of the core. Note that the tip surfaces of the central legs 2121, 3121, the tip surfaces of the upstream legs 2122, 3122, and the tip surfaces of the downstream legs 2123, 3123 are the surfaces facing the conveyance planned surface CP.

[0044] As shown in FIGS. 4 and 5, in this embodiment, an example is given in which the distance (length in the z-axis direction) D between the central legs 2111, 3111 of the non-edge cores 211, 311 and the conveyance planned surface CP 11 is the same as the distance D1 between the central legs 2121, 3121 of the edge cores 212, 312 and the conveyance planned surface CP (in this case, the distance D on the upper inductor 200 side 11 is equal to the distance D on the lower inductor 300 side 11 and preferably, but not necessarily, the distance D1 on the upper inductor 200 side is equal to the distance D1 on the lower inductor 300 side). Therefore, the length D in the z-axis direction of the central legs 2111, 3111 of the non-edge cores 211, 311 12 is the same as the length D5 in the z-axis direction of the central legs 2121, 3121 of the edge cores 212, 312.

[0045] Also, as shown in FIG. 5, in this embodiment, an example is given in which the distance D2 between the upstream legs 2122, 3122 and the conveyance planned surface CP is the same as the distance D3 between the downstream legs 2123, 3123 and the conveyance planned surface CP (in this case, the distance D2 on the upper inductor 200 side is equal to the distance D2 on the lower inductor 300 side, and preferably, but not necessarily, the distance D3 on the upper inductor 200 side is equal to the distance D3 on the lower inductor 300 side). Therefore, the length D6 in the z-axis direction of the upstream legs 2122, 3122 and the length D7 in the z-axis direction of the downstream legs 2123, 3123 are also the same.

[0046] In addition, in the present embodiment, the distances D1 to D3 between the legs (central legs 21 2 1, 31 2 1, upstream legs 2122, 3122, and downstream legs 2123, 3123) of the edge cores 212, 312 and the conveyance planned surface CP are the same is exemplified (in this case, the distance D1 on the upper inducer 200 side is equal to the distance D1 on the lower inducer 300 side, and the distance D2 on the upper inducer 200 side is equal to the distance D2 on the lower inducer 300 side, and the distance D3 on the upper inducer 200 side is preferably equal to the distance D3 on the lower inducer 300 side, but it is not essential.). Therefore, the distances D1 to D3 between the legs of the edge cores 212, 312 and the conveyance planned surface CP and the distance D 11 between the central legs of the non-edge cores 211, 311 and the conveyance planned surface CP are also the same.

[0047] Not only in the present embodiment, but also in the second, third, and fourth embodiments, the distance D1 between the central leg of the edge core and the conveyance planned surface, and the distances D2 and D3 between the upstream and downstream legs of the edge core and the conveyance planned surface are preferably the same. Similarly, not only in the present embodiment, but also in the second, third, and fourth embodiments, the distance D1 between the central leg of the edge core and the conveyance planned surface and the distance D 11 between the central leg of the non-edge core and the conveyance planned surface are preferably the same. Furthermore, not only in the present embodiment, but also in the second, third, and fourth embodiments, the length D 12 in the z-axis direction of the central leg of the non-edge core and the length D5 in the z-axis direction of the central leg of the edge core may be the same, and this length D 12 and D5 may be the same as the lengths D6 and D7 in the z-axis direction of the upstream and downstream legs of the edge core.

[0048] However, it is not always necessary to determine the leg lengths as described above. For example, the distance D 、3111 between the central leg 2111 11It may be longer or shorter than the distances D1 to D3 between the legs of the edge cores 212 to 213 and 312 to 313 and the planned conveyance surface CP. Also, the distance D1 between the central legs 2121 and 3121 of the edge cores 212 to 213 and 312 to 313 and the planned conveyance surface CP may be longer or shorter than the distance D2 between the upstream legs 2122 and 3122 of the edge cores 212 to 213 and 312 to 313 and the planned conveyance surface CP and the distance D3 between the downstream legs 2123 and 3123 of the edge cores 212 to 213 and 312 to 313 and the planned conveyance surface CP. Further, the distance D2 between the upstream legs 2122 and 3122 of the edge cores 212 to 213 and 312 to 313 and the planned conveyance surface CP and the distance D3 between the downstream legs 2123 and 3123 of the edge cores 212 to 213 and 312 to 313 and the planned conveyance surface CP do not have to be the same.

[0049] Also, as shown in FIGS. 4 and 5, the distance D2 between the upstream legs 2122 and 3122 of the edge cores 212 to 213 and 312 to 313 and the planned conveyance surface CP and the distance D3 between the downstream legs 2123 and 3123 of the edge cores 212 to 213 and 312 to 313 and the planned conveyance surface CP are shorter than the distance between the planned conveyance surface CP and the portion of the non-edge core 211 other than the central leg 2111 (note that an example of the degree of this shortness will be described later with reference to FIG. 6). That is, the tip surfaces of the upstream legs 2122 and 3122 of the edge cores 212 to 213 and 312 to 313 are located closer to the planned conveyance surface CP side than the region of the non-edge core 211 other than the central leg 2111.

[0050] As shown in FIG. 5, the shape of the y-z cross section of the edge cores 212 and 312 is E-shaped. That is, the edge cores 212 and 31 2 is a so-called E-shaped core (however, in the example shown in FIG. 5, the lengths of the three horizontal lines of E are all the same).

[0051] Furthermore, the y-z cross-sections of the edge cores 213 and 313 are the same as those of the edge cores 212 and 312 shown in FIG. 5. In FIG. 5, (213), (2131), (2132), (2133), (230b), (313), (3131), (3132), (3133), (330b) attached to 212, 2121, 2122, 2123, 230a, 312, 3121, 3122, 3123, 330a indicate this. Also, as described above, in FIG. 5, the two-dot chain lines indicating the central legs 2121, 3121, the upstream legs 2122, 3122, the downstream legs 2123, 3123, and the body parts 2124, 3124 are virtual lines.

[0052] As shown in FIGS. 1 to 3, the length of the circumferential part of the coils 220 and 320 in the x-axis direction is longer than the width of the strip steel 100. Specifically, the length of the circumferential part of the coils 220 and 320 in the x-axis direction is longer than the maximum processable width of the induction heating device. As a result, when viewed from the z-axis direction, the coils 220 and 320 have a length in the x-axis direction that covers the maximum processable width of the induction heating device. Here, the maximum processable width of the induction heating device is the range in the x-axis direction where the strip steel 100 with the maximum width that can be heated by the induction heating device may exist even if it moves in the positive or negative direction of the x-axis (such as by meandering). Also, both ends of the circumferential part of the coils 220 and 320 in the x-axis direction exist outside both ends of the strip steel 100 in the x-axis direction (that is, both ends of the maximum processable width of the induction heating device). That is, the end on the positive x-axis side of the circumferential part of the coils 220 and 320 exists on the positive x-axis side rather than the end on the positive x-axis side of the strip steel 100 (that is, the maximum processable width of the induction heating device). Also, the end on the negative x-axis side of the circumferential part of the coils 220 and 320 exists on the negative x-axis side rather than the end on the negative x-axis side of the strip steel 100 (that is, the maximum processable width of the induction heating device).

[0053] As shown in FIG. 1, an AC power supply 400 is electrically connected to coils 220 and 320. As shown in FIG. 1, in this embodiment, one end 221 of the circumferential portion of coil 220 is electrically connected to one terminal 401 of the two output terminals of AC power supply 400. Also, the other end 222 of the circumferential portion of coil 220 is electrically connected to the other terminal 402 of the two output terminals of AC power supply 400.

[0054] Among the two ends of the circumferential portion of coil 320, one end 321 located at a position facing one end 221 of the circumferential portion of coil 220 in the z-axis direction is electrically connected to one terminal 401 of the two output terminals of AC power supply 400. Also, among the two ends of the circumferential portion of coil 320, the other end 322 located at a position facing the other end 222 of the circumferential portion of coil 220 in the z-axis direction is electrically connected to the other terminal 402 of the two output terminals of AC power supply 400.

[0055] Thus, in this embodiment, coils 220 and 320 are connected in parallel to AC power supply 400 such that the winding directions of coils 220 and 320 are the same as viewed from AC power supply 400.

[0056] Therefore, as shown in FIG. 1, when viewed from the same perspective at the same time, the directions of the alternating currents flowing in the opposing regions of coils 220 and 320 are the same as each other (see the arrow lines shown inside coils 220 and 320 in FIG. 1).

[0057] The arrow lines shown inside coils 220 and 320 in FIG. 1 indicate that when the induction heating device is viewed from above, the direction of the alternating current flowing in coil 220 is clockwise (right-handed), and the direction of the alternating current flowing in coil 320 is clockwise (right around ) handed.

[0058] Here, the instantaneous values of the alternating current flowing from the AC power supply 400 to the coil 220 and the coil 320 are the same. Note that the waveform of the alternating current is, for example, a sine wave. However, the waveform of the alternating current is not limited to a sine wave. The waveform of the alternating current may be the same as the waveform that can be used in a general induction heating device.

[0059] As described above, the coils 220 and 320 are arranged on the front side and the back side of the planned conveyance surface CP of the strip steel sheet 100 such that the alternating magnetic fields generated by energizing the coils with alternating current in the same direction cross the planned conveyance surface CP of the strip steel sheet 100. In the present embodiment, a case where a pair of coils is constituted by two coils 220 and 320 is illustrated. One of the coils constituting the pair of coils is the coil 220, and the other coil constituting the pair of coils is the coil 320.

[0060] Note that if an alternating current as described above flows through the coil 220 and the coil 320, as shown in FIG. 1, it is not necessary to connect a single AC power supply to the coils 220 and 320. For example, the AC power supply connected to the coil 220 and the AC power supply connected to the coil 320 may be different AC power supplies as long as the frequencies of the currents flowing from these AC power supplies are synchronized.

[0061] Further, in the present embodiment, a case where the number of coils disposed on the front side of the conveyance planned surface CP among the coils constituting the pair of coils included in the induction heating device and the number of coils disposed on the back side of the conveyance planned surface CP among the coils constituting the pair of coils are both 1 is illustrated. However, the number of coils disposed on the front side of the conveyance planned surface CP among the coils constituting the pair of coils included in the induction heating device and the number of coils disposed on the back side of the conveyance planned surface CP among the coils constituting the pair of coils may each be 2 or more. For example, on the front side of the conveyance planned surface CP, two or more coils may be arranged at intervals in the y-axis direction. Similarly, for example, on the back side of the conveyance planned surface CP, two or more coils may be arranged at intervals in the y-axis direction. Among the coils constituting the pair of coils included in the induction heating device, an alternating current in the same direction as the current flowing through the coil 220 flows through two or more coils disposed on the front side of the conveyance planned surface CP. In this case, an alternating current in the same direction as the current flowing through the coil 320 flows through two or more coils disposed on the back side of the conveyance planned surface CP among the coils constituting the pair of coils.

[0062] The shield plates 230a and 230b are an example of a shield member for preventing overheating of the edge portion of the strip steel plate 100 by adjusting (reducing) the electromagnetic coupling degree between the coil 220 and the strip steel plate 100. Specifically, the shield plates 2 3 0a and 2 3 0b are non-magnetic conductive plates disposed between the edge portion of the strip steel plate 100 and the edge cores 212 and 213 of the upper core 210 with a gap therebetween. The length of the shield plates 230a and 230b in the y-axis direction is preferably longer than the length of the upper core 210 (edge cores 212 and 213) in the y-axis direction. Further, it is preferable that the upstream end portions of the shield plates 230a and 230b are upstream of the upstream end of the upper core 210. Similarly, the downstream end portions of the shield plates 2 3 0a and 2 3 0b are preferably downstream of the downstream end of the upper core 210 (see FIG. 5).

[0063] The shielding plates 230a to 230b may move in the x-axis direction within their movable range. The shielding plates 230a and 230b move according to the width of the strip steel plate 100 so that the shielding plates 230a and 230b are positioned between the edge portion of the strip steel plate 100 and the edge cores 212 and 213 of the upper core 210. Further, the shielding plates 230a and 230b may move in the x-axis direction when the strip steel plate 100 meanders. For example, the shielding plates 230a and 230b may move in the x-axis direction (the direction in which the strip steel plate 100 meanders) by the same amount as the meandering amount of the strip steel plate 100.

[0064] Incidentally, the configuration for moving the shielding plates 230a to 230b in the x-axis direction is realized by a known technique using, for example, an actuator for moving the shielding plates 230a to 230b in the x-axis direction. Therefore, a detailed description of the configuration will be omitted here. Also, the configuration for detecting the meandering amount of the plate is realized by a known technique using a sensor for detecting the position of the end portion of the plate in the x-axis direction. Therefore, a detailed description of the configuration will be omitted here. Examples of these known techniques include the technique described in Japanese Patent No. 6658977.

[0065] Also, when the meandering amount of the strip steel plate 100 is on the order of cm (for example, less than 10 cm), it is preferable to move only the shielding plates 230a and 230b in the x-axis direction. When the meandering amount of the strip steel plate 100 exceeds the order of cm (for example, 10 cm or more), it is preferable to move the entire induction heating device (the upper inductor 200 and the lower inductor 300) in the x-axis direction. For example, the entire induction heating device (the upper inductor 200 and the lower inductor 300) may move in the x-axis direction (the direction in which the strip steel plate 100 meanders) by the same amount as the meandering amount of the strip steel plate 100.

[0066] The shielding plates 230a to 230b are arranged at positions close to the upper core 210. Therefore, as described in the section of the problems to be solved by the invention, large eddy currents are generated in the shielding plates 230a and 230b by the alternating magnetic field from the upper core 210 (edge cores 212, 213). The direction of the alternating magnetic field formed by this eddy current is opposite to the direction of the alternating magnetic field from the upper core 210 (edge cores 212, 213). Therefore, in the shielding plates 230a and 230b, the alternating magnetic field from the upper core 210 (edge cores 212, 213) is likely to be rebounded.

[0067] Therefore, in this embodiment, a case where the positions of the non-edge core 211 and the edge cores 212 to 213 in the x-axis direction are determined as follows is exemplified. That is, when the shielding plates 230a and 230b move to the position closest to the center position of the induction heating device in the x-axis direction within the movable range of the shielding plates 230a and 230b in the x-axis direction, the positions in the x-axis direction (x coordinates) of the ends on the plate center side of the edge cores 212 and 213 and the positions in the x-axis direction of the ends on the plate center side of the shielding plates 230a and 230b are the same. Thus, the positions of the non-edge core 211 and the edge cores 212 to 213 in the x-axis direction may be determined. Here, the plate center side refers to the side closer to the center position of the induction heating device in the x-axis direction. On the positive direction side of the x-axis with respect to the center of the induction heating device in the x-axis direction, the plate center side is the negative direction side of the x-axis. On the other hand, on the negative direction side of the x-axis with respect to the center of the induction heating device in the x-axis direction, the plate center side is the positive direction side of the x-axis.

[0068] For example, in FIG. 3, when the shielding plate 230a moves to the most negative direction side of the x-axis within the movable range of the shielding plate 230a, the position x in the x-axis direction of the end on the negative direction side of the x-axis of the shielding plate 230a s1 and the position x in the x-axis direction of the end on the negative direction side of the x-axis of the edge core 212 e1 are the same, the positions of the non-edge core 211 and the edge core 212 in the x-axis direction may be determined.

[0069] In FIG. 3, the positions in the x-axis direction of the ends on the plate center side of the edge cores 212 and 213 xe1 、x e2 and the positions in the x-axis direction of the end portions on the plate center side of the shield plates 230a and 230b x s1 、x s2 are the same respectively (x s1 = x e1 、x s2 = x e2 ). Therefore, in FIG. 3, the state is shown when the shield plates 230a and 230b move to the positions closest to the position of the center in the x-axis direction of the induction heating device within the movable range in the x-axis direction of the shield plates 230a and 230b.

[0070] That is, in FIG. 3, an example is shown where the position x in the x-axis direction of the end portion on the negative direction side of the x-axis of the shield plate 230a s1 and the position x in the x-axis direction of the end portion on the negative direction side of the x-axis of the edge core 212 e1 are the same. Similarly, in FIG. 3, an example is shown where the position x in the x-axis direction of the end portion on the positive direction side of the x-axis of the shield plate 230b s2 and the position x in the x-axis direction of the end portion on the positive direction side of the x-axis of the edge core 213 e2 are the same. Therefore, in FIG. 3, the state is shown when the shield plate 230a moves to the most negative direction side in the movable range of the shield plate 230a, and the shield plate 230b moves to the most positive direction side in the movable range of the shield plate 230b.

[0071] As described above, the edge cores 212 to 213 are so-called E-shaped cores. Therefore, by determining the positions of the non-edge core 211 and the edge cores 212 to 213 in the x-axis direction as described above, even if the alternating magnetic field (magnetic flux) from the three magnetic pole surfaces of the edge cores 212 and 213 is bounced back by the shield plates 230a and 230b, it returns to the upper core 210 from any one of the three magnetic pole surfaces. Therefore, it is possible to suppress the diffusion of the alternating magnetic field (magnetic flux) bounced back by the shield plates 230a and 230b as noise around the induction heating device. Here, the three magnetic pole surfaces of the edge core 212 are the tip surfaces of the central leg portion 2121, the upstream leg portion 2122, and the downstream leg portion 2123. The three magnetic pole surfaces of the edge core 213 are the tip surfaces of the central leg portion 2131, the upstream leg portion 2132, and the downstream leg portion 2133.

[0072] On the other hand, by determining the positions of the non-edge core 211 and the edge cores 212 to 213 in the x-axis direction as described above, the non-edge core 211 does not face the shield plates 230a to 230b. Therefore, by making the non-edge core 211 a so-called T-shaped core, it is possible to easily reach the alternating magnetic field from the magnetic pole surface (the tip surface of the central leg portion 2111) of the non-edge core 211 to the strip steel plate 100. Therefore, the central region in the x-axis direction of the induction heating device can be efficiently heated.

[0073] In addition, for example, when the influence of the alternating magnetic field (magnetic flux) bounced back by the shield plates 230a and 230b is low, the position in the x-axis direction of the end portion on the plate center side of the edge cores 212 and 213 x e1 、x e2 and the position in the x-axis direction of the end portion on the plate center side of the shield plates 230a and 230b x s1 、x s2 The relationship with is described above forIt may not be necessary to determine it in this way. When the influence of the alternating magnetic field (magnetic flux) rebounded by the shielding plates 230a and 230b is low, for example, it includes at least one of the cases where an object affected by the alternating magnetic field (magnetic flux) (such as an electronic device) does not exist near the induction heating device and the case where the strip steel plate 100 to be heated is of low quality.

[0074] The movable range of the shielding plates 230a and 230b in the x-axis direction is determined at the time of designing the induction heating device, mainly considering the maximum processable width and the minimum processable width of the induction heating device. Here, the minimum processable width of the induction heating device is the range in the x-axis direction where there is a possibility that the strip steel plate 100 with the minimum width that can be heated by the induction heating device exists even if it moves in the positive or negative direction of the x-axis (such as by meandering). Also, as described above, the maximum processable width of the induction heating device is the range in the x-axis direction where there is a possibility that the strip steel plate 100 with the maximum width that can be heated by the induction heating device exists even if it moves in the positive or negative direction of the x-axis (such as by meandering). The position of the end portion on the plate center side of the edge cores 212 and 213 in the x-axis direction x e1 、x e2 (The boundary position in the x-axis direction between the non-edge core 211 and the edge cores 212 and 213) cannot move during the use of the induction heating device like the shielding plates 230a and 230b. For this reason, the position of the end portion on the plate center side of the edge cores 212 and 213 in the x-axis direction x e1 、x e2 is preferably determined in consideration of various factors other than the movable range of the shielding plates 230a and 230b in the x-axis direction. The various factors include, for example, the arrangement status of electronic devices near the induction heating device, the design target of the heating efficiency of the strip steel plate 100, and the distribution of the plate width of the strip steel plate 100 processed by the induction heating device. When there is a change in the above factors, such as when an electronic device is newly arranged near the induction heating device after the installation of the induction heating device, the position of the end portion on the plate center side of the edge cores 212 and 213 in the x-axis direction x e1 、x e2The induction heating device may be modified so that it is corrected to a position corresponding to the change.

[0075] The lower inductor 300 also includes a lower core 310, a coil 320, and shield plates 330a and 330b, similar to the upper inductor 200, and has the same configuration as the upper inductor 200. The lower core 310 has a non-edge core 311 and edge cores 312 and 313. The non-edge core 311 has a central leg portion 3111 and a body portion 3112. The edge cores 312 and 313 have central leg portions 3121 and 3131, upstream leg portions 3122 to 31 3 2, downstream leg portions 31 23 ~313 3 and body portions 3124 and 3134. In addition, the meaning of the two-dot chain line notation shown for the lower core 310 in FIGS. 4 and 5 and the meaning of the symbol notation shown in parentheses for the lower core 310 in FIG. 5 are the same as the meaning of the notation for the upper core 210. Also, the x shown in the figure 3 , x s3 , x s4 , x e3 , x e4 mean, respectively, x s1 , x s2 , x e1 , x e2 and have the same meaning.

[0076] In the present embodiment, a case is exemplified in which cores arranged in pairs for each one coil constituting a pair of coils are configured by the upper core 210 and the lower core 310. One of the cores constituting the pair of cores is the upper core 210, and the other core constituting the pair of cores alpha is is the lower core 310.

[0077] As described above, in the present embodiment, the non-edge cores 211 and 311 are so-called T-shaped cores. Also, the two edge cores 212 to 213 and 312 to 313 arranged on both sides in the x-axis direction with respect to the non-edge cores 211 and 311 are so-called E-shaped cores. Further, the intervals between the upstream legs 2122 and 3122 and the downstream legs 2123 and 3123 of the edge cores 212 and 313 and the conveyance planned surface CP are made shorter than the intervals between the portions of the non-edge cores 211 and 311 other than the central legs 2111 and 3111 and the conveyance planned plane CP and ,. Therefore, in the edge portion of the strip steel sheet 100 where overheating is a concern in the transverse induction heating device, it is possible to preferentially suppress the diffusion of the alternating magnetic field (magnetic flux) from the core rather than suppressing the decrease in the magnitude of the alternating magnetic field applied to the strip steel sheet 100 (heating efficiency of the strip steel sheet 100). On the other hand, in the region closer to the center of the plate than the edge portion of the strip steel sheet 100, it is possible to preferentially suppress the decrease in the magnitude of the alternating magnetic field applied to the strip steel sheet 100 rather than the diffusion of the alternating magnetic field (magnetic flux) from the core suppression of . Therefore, it is possible to achieve both generating an alternating magnetic field of a desired magnitude and suppressing the diffusion of the alternating magnetic field as unintended heating or noise to the surroundings. Thus, it is possible to realize an induction heating device aimed at achieving both suppression of the decrease in the magnitude of the alternating magnetic field applied to the strip steel sheet 100 and suppression of the diffusion of the alternating magnetic field. Such an effect becomes remarkable as the capacity of the induction heating device increases. Although the capacity of the induction heating device of the present embodiment is not limited, from such a viewpoint, when the capacity of the induction heating device is on the order of ten kW or more (for example, 10 kW or more), such an effect becomes remarkable, which is preferable.

[0078] Also, in the present embodiment, when the shield plates 230a and 230b move to the position closest to the center position in the x-axis direction of the induction heating device within the movable range in the x-axis direction of the shield plates 230a and 230b, the x-axis direction positions x of the ends on the plate center side of the edge cores 212 and 213 e1 , x e2 and the x-axis direction positions x of the ends on the plate center side of the ends of the shield plates 230a and 230b s1 , x s2The positions of the non-edge cores 211 and the edge cores 212 to 213 in the x-axis direction may be determined so as to be the same. Therefore, even when the shield plates 230a and 230b are used to suppress overheating of the edge portions of the strip steel plate 100, it is possible to suppress the surrounding objects (for example, electronic devices) from being heated and noise from being generated in the surrounding objects due to the alternating magnetic field from the core diffusing from the induction heating device.

[0079] <Modification Example> In the present embodiment, when the shield plates 230a and 230b move to the position closest to the center position of the induction heating device in the x-axis direction within the movable range of the shield plates 230a and 230b in the x-axis direction, the x-axis direction position x of the end portions on the plate center side of the edge cores 212 and 213 e1 、x e2 and the x-axis direction position x of the end portions on the plate center side of the end portions of the shield plates 230a and 230b s1 、x s2 are the same. As described above, this is preferable because the suppression effect of suppressing the alternating magnetic field from the core from diffusing from the induction heating device can be enhanced. However, it is not always necessary to do so. For example, when the shield plates 230a and 230b move to the position closest to the center position of the induction heating device in the x-axis direction within the movable range of the shield plates 230a and 230b in the x-axis direction, the x-axis direction position x of the end portions on the plate center side of the edge cores 212 and 213 e1 、x e2 may be located closer to the plate center side than the x-axis direction position x of the end portions on the plate center side of the shield plates 230a and 230b s1 、x s2 or may be located on the side opposite to the plate center side. In the following description, the side opposite to the plate center side is referred to as the plate end side as necessary. Here, on the positive direction side of the x-axis with respect to the center of the induction heating device in the x-axis direction, the plate end side is the positive direction side of the x-axis. On the other hand, on the negative direction side of the x-axis with respect to the center of the induction heating device in the x-axis direction, the plate end side is the negative direction side of the x-axis.

[0080] In addition, in the present embodiment, the case where the non-edge cores 211 and 311 are so-called T-shaped cores is exemplified. However, if the distance (in the z-axis direction) between the tip surfaces of the upstream leg portions 2122 and 3122 of the edge cores 212 to 213 and 312 to 313 and the strip steel plate 100 is shorter than the distance (in the z-axis direction) between the strip steel plate 100 and the regions other than the central leg portion 2111 in the region of the non-edge core 211, the non-edge cores 211 and 311 are not limited to T-shaped cores. For example, as shown in FIG. 6, the non-edge cores 211 and 311 may be configured (FIG. 6 is a cross-sectional view corresponding to FIG. 4).

[0081] In the example shown in FIG. 6, the non-edge core 211 has an upstream leg portion 2113 and a downstream leg portion 2114 in addition to the central leg portion 2111 and the body portion 2112. In the example shown in FIG. 6, the upstream leg portion 2113 extends from the body portion 2112 in the direction of the conveyance planned surface CP on the upstream side (the negative direction side of the y-axis) of the coil 220. The downstream leg portion 2114 extends from the body portion 2112 in the direction of the conveyance planned surface CP on the downstream side (the positive direction side of the y-axis) of the coil 220.

[0082] The upstream leg portion 2113 and the downstream leg portion 2114 are arranged at intervals from the central leg portion 2111 on both sides of the central leg portion 2111 in the y-axis direction. In the example shown in FIG. 6, in addition to the tip surface of the central leg portion 2111, the tip surfaces of the upstream leg portion 2113 and the downstream leg portion 2114 are also magnetic pole surfaces.

[0083] In FIG. 6, the non-edge core 211 、311 The length D in the z-axis direction of the central leg portions 2111 and 3111 12 is the length D in the z-axis direction of the upstream leg portions 2113 and 3113 and the downstream leg portions 2114 and 3114 14 、D 16 of the non-edge cores 211 and 311. For example, from the viewpoint of suppressing the diffusion of the alternating magnetic field from the core, the non-edge core 211 、311 The length D in the z-axis direction of the central leg portions 2111 and 3111 12The lengths D in the z-axis direction of the upstream legs 2113 and 3113 and the downstream legs 2114 and 3114 of the non-edge cores 211 and 311 with respect to 14 D 16 The ratios may each be 0.95 or less (D 14 / D 12 ≤0.95, D 16 / D 12 ≤0.95). Also, D 13 ≥D 11 +D 12 ×0.05 and D 15 ≥D 11 +D 12 ×0.05 may also be acceptable. Further, for example, from the perspective of suppressing a decrease in the heating efficiency of the strip steel 100, the length D in the z-axis direction of the central legs 2111 and 3111 of the non-edge core 211 、311 The lengths D in the z-axis direction of the upstream legs 2113 and 3113 and the downstream legs 2114 and 3114 of the non-edge cores 211 and 311 with respect to 12 D 14 The ratios may each be 0.90 or less (D 16 / D 14 / D 12 ≤0.90, D 16 / D 12 ≤0.90). Also, D 13 ≥D 11 +D 12 ×0.10 and D 15 ≥D 11 +D 12 ×0.10 may also be acceptable.

[0084] Also, in FIGS. 5 and 6, an example is illustrated where the distance D 、3113 between the upstream leg 2113 of the non-edge cores 211 and 311 and the planned conveyance plane CP 13 is longer than the distance D2 between the upstream leg 2122 of the edge cores 212 to 213 and 312 to 313 and the planned conveyance plane CP. Therefore, the length D in the z-axis direction of the upstream leg 2113 of the non-edge cores 211 and 311 、3122 is the upstream leg 2122 of the edge cores 212 to 213 and 312 to 313 、3113 The length D in the z-axis direction of 14 is 、3122Similarly, in FIG. 5 and FIG. 6, the length D6 of the downstream leg 2114 of the non-edge core 211, 311 is shorter than the length D6 of the downstream leg 2114 of the non-edge core 211, 311 in the z-axis direction. 、3114 and the distance D between the planned conveying surface CP 15 However, the downstream leg portion 2123 of the edge cores 212 to 213 and 312 to 313 、3123 The case where the distance D3 between the downstream leg 2114 and the intended transport surface CP is longer than the distance D3 between the downstream leg 2114 and the intended transport surface CP is illustrated. 、3114 The length D in the z-axis direction of 16 The downstream leg 2123 of the edge cores 212-213 and 312-313 、3123 6, the distance D2 between the upstream legs 2122, 3122 of the edge cores 212-213, 312-313 and the intended transport surface CP and the distance D3 between the downstream legs 2123, 3123 of the edge cores 212-213, 312-313 and the intended transport surface CP are shorter than the distance between the portion of the non-edge core 211 other than the central leg 2111 and the intended transport surface CP.

[0085] For example, from the viewpoint of suppressing the diffusion of the alternating magnetic field from the core, the distance D2 between the upstream leg portions 2122, 3122 of the edge cores 212-213, 312-313 and the intended transport surface CP is set to be smaller than the distance D2 between the central leg portion 2111 of the non-edge cores 211, 311. 、3111 The distance between the upstream leg portions 2122 and 3122 and the intended conveying surface CP is shorter than the distance D6 in the z-axis direction by 0.05 or more. by Similarly, the distance D3 between the downstream leg portions 2123, 3123 of the edge cores 212 to 213, 312 to 313 and the intended transport surface CP is 、3111 The distance may be shorter than the distance between the remaining portion and the intended transport surface CP by 0.05 or more times the length D7 of the downstream leg portions 2123 and 3123 in the z-axis direction.

[0086] Further, for example, from the viewpoint of suppressing a decrease in the heating efficiency of the strip steel 100, the distance D2 between the upstream leg portions 2122 and 3122 of the edge cores 212 to 213 and 312 to 313 and the conveyance planned surface CP is the central leg portion 2111 among the portions of the non-edge cores 211 and 311 、3111 It may be shorter than 0.10 times or 0.20 times or more of the length D6 in the z-axis direction of the upstream leg portions 2122 and 3122 than the distance between the conveyance planned surface CP and the portion other than the central leg portion 2111. Similarly, the distance D3 between the downstream leg portions 2123 and 3123 of the edge cores 212 to 213 and 312 to 313 and the conveyance planned surface CP is the central leg portion 2111 among the portions of the non-edge cores 211 and 311 、3111 It may be shorter than 0.10 times or 0.20 times or more of the length D7 in the z-axis direction of the downstream leg portions 2123 and 3123 than the distance between the conveyance planned surface CP and the portion other than the central leg portion 2111 upper short It may be shorter. In addition to the present embodiment, in the second embodiment, the third embodiment, and the fourth embodiment, the same degree of shortness (that is, 0.05 times or more, 0.10 times or more, or 0.20 times or more) as described above may be adopted.

[0087] Using the non-edge cores 211 and 311 shown in FIG. 6 causes the heating efficiency of the strip steel 100 to decrease compared to using the non-edge cores 211 and 311 shown in FIGS. 1 to 5, but the diffusion of the alternating magnetic field from the core can be suppressed. Therefore, for example, in consideration of both suppressing a decrease in the heating efficiency of the strip steel 100 and suppressing the diffusion of the alternating magnetic field from the core, whether to adopt the non-edge cores 211 and 311 (see FIG. 4) having the central leg portion 2111 and not having the upstream leg portion and the downstream leg portion, or the non-edge cores 211 and 311 (see FIG. 6) having the central leg portion 2111, the upstream leg portion 2113, and the downstream leg portion 2114 may be determined.

[0088] The non-edge core 311 of the lower core 310 also has an upstream leg portion 3113 and a downstream leg portion 3114 in addition to the central leg portion 3111 and the body portion 3112, similar to the non-edge core 211 of the upper core 210. The upstream leg portion 3113 and the downstream leg portion 3114 are arranged on both sides of the central leg portion 3111 in the y-axis direction with a space from the central leg portion 3111.

[0089] In addition, in the present embodiment, a case where the y-z cross-sections of the edge cores 212 and 213 are the same regardless of the position in the x-axis direction is illustrated. However, it is not necessarily required to be like this. For example, the edge cores 212 and 213 do not necessarily have to be congruent, and may have different shapes, such as an E-core arranged on the plate edge side and an E-core arranged on the plate center side. For example, the distances between the three legs (central leg, upstream leg, and downstream leg) of the E-core arranged on the plate edge side and the conveyance planned surface CP may be longer or shorter than the distances between the three legs (central leg, upstream leg, and downstream leg) of the E-core arranged on the plate center side and the conveyance planned surface CP.

[0090] In addition, in the present embodiment, a case where the non-edge cores 211 and 311 and the edge cores 212 to 213 and 312 to 313 are made of the same material (electromagnetic steel sheet) is illustrated. However, it is not necessary for the non-edge cores 211 and 311 and the edge cores 212 to 213 and 312 to 313 to be made of the same material. For example, at least one of the non-edge cores 211 and 311 and the edge cores 212 to 213 and 312 to 313 may be made of soft magnetic ferrite.

[0091] In addition, in the present embodiment, a case where the induction heating device includes the shield plates 230a and 230b is illustrated. However, it is not necessarily required to be like this. For example, at the position where the shield plates 230a and 230b are arranged, a secondary coil for adjusting (reducing) the electromagnetic coupling degree between the coil 220 and the strip steel sheet 100 may be arranged as an example of a shield member in order to prevent overheating of the edge portion of the strip steel sheet 100.

[0092] As described above, various modification examples of the present embodiment have been described. A modification example combining at least two of these modification examples, including the modification examples of the present embodiment described before the description of the "Modification Example" section, may be adopted for the induction heating device of the present embodiment.

[0093] (Second Embodiment) Next, a second embodiment of the present invention will be described. In the first embodiment described above, the case where the upper core 210 and the lower core 310 are each one core was exemplified. Therefore, there is no gap in the x-axis direction between the upper core 210 and the lower core 310.

[0094] In a transverse induction heating device, iron loss occurs, causing the core to generate heat and its temperature to rise. Also, in a transverse induction heating device, in order to generate a large magnetic field, a coil for heating the strip steel sheet 100 is wound around the core. Therefore, the heat generation of the core becomes prominent. Further, the heat generation of the core becomes prominent in an induction heating device with a large-capacity power supply. In this regard, although the heat generation of the core is not considered in the techniques described in Patent Documents 5 and 6, the core is divided into a plurality of parts. The total cross-sectional area of the plurality of divided cores is larger than the surface area of the non-divided core. The larger the surface area of the core, the more the heat dissipation from the core is promoted. Therefore, the heat generation of the plurality of divided cores is suppressed compared to the heat generation of the non-divided core.

[0095] When the core is divided into a plurality of parts in the x-axis direction, the temperature of the core decreases. However, the alternating magnetic field in the core is interrupted. Therefore, when the core is divided into a plurality of parts in the x-axis direction, there is a possibility that an alternating magnetic field of a desired magnitude cannot be applied to the strip steel sheet 100. As a result, the heating efficiency of the strip steel sheet 100 decreases and a bias occurs in the temperature distribution of the strip steel sheet 100 in the x-axis direction. The inventors have confirmed that when the core of a general transverse induction heating device is divided into a plurality of parts in the x-axis direction, the temperature of the edge portion of the strip steel sheet 100 may drop by 100°C or more compared to the temperature of other portions of the strip steel sheet 100.

[0096] In order to suppress the temperature drop of such a strip steel plate 100 (i.e., in order for an alternating magnetic field of a desired magnitude to intersect the strip-shaped conductor plate), if the number of divisions of the core is reduced, the temperature of the core cannot be reduced to the desired temperature. On the other hand, if the number of divisions of the core is increased so as to reduce the temperature of the core to the desired temperature, the temperature drop of the strip steel plate 100 cannot be suppressed (i.e., an alternating magnetic field of a desired magnitude cannot intersect the strip-shaped conductor plate). In the techniques described in Patent Documents 5 and 6, the core is divided in order to suppress overheating of the edge portion of the strip steel plate 100. Therefore, the number of divisions of the core is determined so as to be able to suppress overheating of the edge portion of the strip steel plate 100 and heat generation of the core. Therefore, the techniques described in Patent Documents 5 and 6 do not even recognize the problem of suppressing the rise in the temperature of the core and the decrease in the magnitude of the alternating magnetic field applied to the conductor. Thus, the conventional technique has a problem that it cannot simultaneously satisfy both the suppression of the rise in the temperature of the core and the suppression of the decrease in the magnitude of the alternating magnetic field applied to the strip-shaped conductor.

[0097] Therefore, in the present embodiment, in addition to aiming at achieving both the suppression of the decrease in the magnitude of the alternating magnetic field applied to the strip steel plate 100 and the suppression of the diffusion of the alternating magnetic field as in the first embodiment, an example of an induction heating device that can simultaneously satisfy both the suppression of the rise in the temperature of the core and the suppression of the decrease in the magnitude of the alternating magnetic field will be described. Thus, in the present embodiment, a configuration for simultaneously satisfying both the suppression of the rise in the temperature of the core and the suppression of the decrease in the magnitude of the alternating magnetic field is added to the first embodiment. Therefore, in the description of the present embodiment, for the same parts as those in the first embodiment, the same reference numerals as those attached to FIGS. 1 to 6 are used and the detailed description is omitted.

[0098] FIG. 7 is a diagram showing an example of the external configuration of the induction heating device. FIG. 7 is a diagram corresponding to FIG. 1. The induction heating device shown in Fig. 7 includes an upper inductor 600 and a lower inductor 700. The upper inductor 600 and the lower inductor 700 are arranged at positions facing each other via the planned conveyance surface CP. The upper inductor 600 and the lower inductor 700 have the same configuration. Therefore, here, the upper inductor 600 will be described in detail, and the detailed description of the lower inductor 700 will be omitted as necessary. Note that the distance between the upper inductor 600 and the strip steel sheet 100 and the distance between the lower inductor 700 and the strip steel sheet 100 may or may not be the same. In this embodiment as well as in the first embodiment, a case where the induction heating device has a shape with a mirror-symmetric relationship with the y-z plane at the center in the x-axis direction of the induction heating device as the symmetry plane will be exemplified. When the distance between the upper inductor 600 and the planned conveyance surface CP and the distance between the lower inductor 700 and the planned conveyance surface CP are the same, the induction heating device has a shape with a mirror-symmetric relationship with the planned conveyance surface CP as the symmetry plane.

[0099] Fig. 8 is a diagram showing an example of a first cross-section of the induction heating device. Specifically, Fig. 8 is a cross-sectional view taken along line I-I in Fig. 7. Fig. 9 is a diagram showing an example of a second cross-section of the induction heating device. Specifically, Fig. 9 is a cross-sectional view taken along line II-II in Fig. 7. Fig. 10 is a diagram showing an example of a third cross-section of the induction heating device. Specifically, Fig. 10 is a cross-sectional view taken along line III-III in Fig. 7. Fig. 11 is a diagram showing an example of a fourth cross-section of the induction heating device. Specifically, Fig. 11 is a cross-sectional view taken along line IV-IV in Fig. 7.

[0100] In Figs. 8 and 9, the upper inductor 600 includes an upper core 610, bridge cores 620a to 620b, a coil 220, shield plates 230a to 230b, cooling fins 630a to 630h, and cooling small tubes 640a to 640h.

[0101] The upper core 610 is formed using a ferromagnetic material. As shown in Figs. 8 and 9, the upper core 610 has a non-edge core 611 and two edge cores 612 to 613. The edge cores 612 and 613 are arranged on both sides of the non-edge core 611 in the x-axis direction. Similar to the first embodiment, this embodiment exemplifies the case where the position of the center of the upper core 610 in the x-axis direction is included in the positions of the non-edge core 611 in the x-axis direction.

[0102] Also, similar to the first embodiment, this embodiment exemplifies the case where the non-edge core 611 and the two edge cores 612 to 613 are integrated. Therefore, there is no boundary line between the non-edge core 611 and the edge cores 612 to 613.

[0103] The non-edge core 611 has a plurality of partial non-edge cores 611a to 611c arranged at intervals in the x-axis direction. Also, the edge cores 612 and 613 each have a plurality of partial edge cores 612a to 612c and 613a to 613c arranged at intervals in the x-axis direction.

[0104] Here, the state where two partial edge cores have an interval does not only mean a state where the two partial edge cores are not physically in contact with each other. For example, even if a part of the two partial edge cores is in contact with each other, if the two partial edge cores are not magnetically sufficiently coupled, the magnetic flux density in each partial core is lower than the case where a ferromagnetic material of the same material as the partial core exists between the two partial cores (for example, a state where it has decreased by 50% or more or 80% or more). Such a state can also be regarded as a state where the two partial edge cores have an interval. That is, even in such a state, the magnetic flux density in the partial edge core can be restored to the same level as the magnetic flux density in the main core by the bridge core described later.

[0105] In this embodiment, a case is exemplified in which partial non-edge cores 611a to 611c are formed by a plurality of electromagnetic steel sheets laminated in the x-axis direction, the thickness and planar shape of which are the same as those of the electromagnetic steel sheets constituting the non-edge core 211 of the first embodiment. Also, a case is exemplified in which partial edge cores 612a to 612c, 613a to 613c are formed by a plurality of electromagnetic steel sheets laminated in the x-axis direction, the thickness and planar shape of which are the same as those of the electromagnetic steel sheets constituting the edge cores 212, 213 of the first embodiment. Therefore, the y-z cross section of the partial non-edge cores 611a to 611c is the same as the y-z cross section of the non-edge core 211 shown in FIG. 4. Therefore, each of the partial non-edge cores 611a to 611c has a central leg portion and a body portion similar to the central leg portions 2111, 3111 and the body portions 2112, 3112 of the non-edge core 211. Also, the y-z cross section of the partial edge cores 612a to 612c, 613a to 613c is the same as the y-z cross section of the edge core 212 shown in FIG. 5. Therefore, each of the partial edge cores 612a to 612c, 613a to 613c has a central leg portion, an upstream leg portion, a downstream leg portion, and a body portion similar to the central leg portion 2121, the upstream leg portion 2122, the downstream leg portion 2123, and the body portion 2124 of the edge core 212. 、311 has central leg portions and body portions similar to the central leg portions 2111, 3111 and the body portions 2112, 3112. Also, the y-z cross section of the partial edge cores 612a to 612c, 613a to 613c is the same as the y-z cross section of the edge core 212 shown in FIG. 5. Therefore, each of the partial edge cores 612a to 612c, 613a to 613c has a central leg portion, an upstream leg portion, a downstream leg portion, and a body portion similar to the central leg portion 2121, the upstream leg portion 2122, the downstream leg portion 2123, and the body portion 2124 of the edge core 212.

[0106] The plurality of electromagnetic steel sheets constituting each of the partial non-edge cores 611a to 611c are fixed so as not to separate from each other. Also, the plurality of electromagnetic steel sheets constituting each of the partial edge cores 612a to 612c, 613a to 613c are fixed so as not to separate from each other. The method of fixing the plurality of electromagnetic steel sheets is not limited. For example, various known methods such as fixing with an adhesive, fixing by welding, fixing by caulking, and fixing using a fixing member are adopted as the method of fixing the plurality of electromagnetic steel sheets. For convenience of notation, in FIGS. 8 and 9, the illustration of the boundary lines of the individual electromagnetic steel sheets is omitted.

[0107] In FIGS. 8 and 9, cooling fins 630a, 630b, 630c, and 630d are respectively disposed between partial edge cores 612a and 612b, between partial edge cores 612b and 612c, between partial edge core 612c and partial non-edge core 611a, and between partial non-edge cores 611a and 611b. Similarly, cooling fins 630e, 630f, 630g, and 630h are respectively disposed between partial edge cores 613a and 613b, between partial edge cores 613b and 613c, between partial edge core 613c and partial non-edge core 611c, and between partial non-edge cores 611c and 611b. In this embodiment, a case where the intervals between these are fixed (not changed) is illustrated. However, the intervals between these may be changeable. Also, the lengths of each of the partial edge cores 612a to 612c and 613a to 613c in the x-axis direction may be the same or different from each other.

[0108] The cooling fins 630a to 630h are an example of a cooling member for cooling the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c and 613a to 613c. In this embodiment, a case where the cooling fins 630a to 630h are fin-shaped non-magnetic conductive plates is illustrated. The cooling fins 630a to 630h are constituted by, for example, copper plates.

[0109] Cooling small tubes 640a to 640h are attached on the cooling fins 630a to 630h. The cooling small tubes 640a to 640h are an example of a cooling member for cooling the partial non-edge cores 611a to 611c, the partial edge cores 612a to 612c and 613a to 613c, and the bridge cores 620a and 620b. In this embodiment, a case where the cooling small tubes 640a to 640h are non-magnetic conductive tubes is illustrated.

[0110] The cooling fins 630a to 630h and the cooling small tubes 640a to 640h attached thereon are in contact with each other. Also, in FIG. 10, an example is shown where the outer shape of the entire y-z cross-section of the combined region of the cooling fins 630a to 630c, 630e to 630g and the cooling small tubes 640a to 640c, 640e to 640g is the same as the outer shape of the y-z cross-section of the edge core 212 shown in FIG. 5. That is, in FIG. 10, an example is shown where the shape and size of the entire region of the cooling fin 630a and the cooling small tube 640a are the same as the shape and size of the region of the edge core 212 in FIG. 5. Incidentally, as described above, the y-z cross-sections of the partial edge cores 612a to 612c, 613a to 613c are the same as the y-z cross-section of the edge core 212 shown in FIG. 5. Therefore, the outer shape of the entire y-z cross-section of the combined region of the cooling fins 630a to 630c, 630e to 630g and the cooling small tubes 640a to 640c, 640e to 640g is the same as the outer shape of the y-z cross-sections of the partial edge cores 612a to 612c, 613a to 613c.

[0111] Also, in FIG. 11, an example is shown where the outer shape of the entire y-z cross-section of the combined region of the cooling fins 630d, 630h and the cooling small tubes 640d, 640h is the same as the outer shape of the y-z cross-section of the non-edge core 211 shown in FIG. 4. That is, in FIG. 11, an example is shown where the shape and size of the entire region of the cooling fin 630d and the cooling small tube 640d are the same as the shape and size of the region of the non-edge core 211 in FIG. 4. Incidentally, as described above, the y-z cross-sections of the partial non-edge cores 611a to 611c are the same as the y-z cross-section of the non-edge core 211 shown in FIG. 4. Therefore, the outer shape of the entire y-z cross-section of the combined region of the cooling fins 630d, 630h and the cooling small tubes 640d, 640h is the same as the outer shape of the y-z cross-sections of the partial non-edge cores 611a to 611c.

[0112] As shown in FIGS. 10 and 11, the shape of the y-z cross-section of the cooling fins 630a to 630c, 630e to 630g is E-shaped, while the shape of the y-z cross-section of the cooling fins 630d, 630h is T-shaped. The cooling fins 630a to 630c, 630e to 630g and the cooling fins 630d, 630h differ in this regard.

[0113] A cooling medium such as cooling water is supplied into the cooling small tubes 640a to 640h. Heat conduction is performed from the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c, 613a to 613c, etc. to this cooling medium through the cooling small tubes 640a to 640h and the cooling fins 630a to 630h. Therefore, the cooling of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c, 613a to 613c, etc. is promoted.

[0114] In the present embodiment, an example is given in which the shapes and sizes when the partial non-edge cores 611a to 611c, the cooling fins 630d, 630h, and the cooling small tubes 640d, 640 h are combined as shown in FIGS. 8 and 9 are the same as the shape and size of the non-edge core 211 of the first embodiment. Further, an example is given in which the shapes and sizes when the partial edge cores 612a to 612c, the cooling fins 630a to 630c, and the cooling small tubes 640a to 640c are combined as shown in FIGS. 8 and 9 are the same as the shape and size of the edge core 21 2 of the first embodiment. Similarly, an example is given in which the shapes and sizes when the partial edge cores 613a to 613c, the cooling fins 630e to 630g, and the cooling small tubes 640e to 640g are combined as shown in FIGS. 8 and 9 are the same as the shape and size of the edge core 213 of the first embodiment. However, it is not necessarily required to be like this.

[0115] Due to the magnetic field based on the eddy current flowing in the shield plates 230a and 230b, the temperature of the upper core 610 becomes the highest near the upper part of the end on the plate center side of the shield plates 230a and 230b. Therefore, in the present embodiment, an example is given in which the positions (x coordinates) in the x-axis direction of the non-edge core 611 and the positions in the x-axis direction of the edge cores 612 and 613 are determined as follows.

[0116] The non-edge core 611 and the edge cores 612, 6The region of the gap in the x-axis direction formed at 13 is referred to as the core gap region. In the present embodiment, an example is illustrated in which the core gap region is a region where the cooling fins 630a to 630h and the cooling small tubes 640a to 640h are arranged. In the present embodiment, when the shield plates 230a and 230b move to the position closest to the center position in the x-axis direction of the induction heating device within the movable range in the x-axis direction of the shield plates 230a and 230b, among the core gap regions existing at the position facing the bridge cores 620a and 620b, the end on the plate center side of the core gap region closest to the plate center is arranged inside (on the plate center side) the end on the plate center side of the shield plates 230a and 230b. An example is illustrated in which the positions in the x-axis direction of the partial non-edge cores 611a to 611c and the positions in the x-axis direction of the partial edge cores 612a to 612c and 613a to 613c are determined. In FIGS. 8 and 9, an example is illustrated in which the end on the plate center side of the core gap region closest to the plate center among the core gap regions existing at the position facing the bridge cores 620a and 620b is the end on the plate center side of the cooling fins 630d and 630h, respectively.

[0117] In this way, by determining the positions in the x-axis direction of the partial non-edge cores 611a to 611c and the positions in the x-axis direction of the partial edge cores 612a to 612c and 613a to 613c, the region between the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c and 613a to 613c can be positioned near the region where the temperature of the upper core 610 described above becomes high. Therefore, the temperature of the region where the temperature of the upper core 610 described above becomes high can be reduced. Further, as in the present embodiment, if the cooling fins 630a to 630h and the cooling small tubes 640a to 640h are arranged in the region between the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c and 613a to 613c, the temperature of the region where the temperature of the upper core 610 described above becomes high can be reduced more.

[0118] For example, in FIGS. 8 and 9, when the shield plate 230a moves to the most negative x-axis direction within the movable range of the shield plate 230a, the negative x-axis direction end of the cooling fin 630d is positioned more on the negative x-axis direction side than the negative x-axis direction end of the shield plate 230a. The x-axis direction positions of the partial non-edge cores 611a to 611c and the x-axis direction positions of the partial edge cores 612a to 612c and 613a to 613c are determined accordingly. Note that FIGS. 8 and 9, similar to FIGS. 2 and 3, show the state when the shield plates 230a and 230b move to the position closest to the center position of the induction heating device in the x-axis direction within the x-axis direction movable ranges of the shield plates 230a and 230b.

[0119] The bridge cores 620a and 620b are ferromagnetic materials that can be magnetically coupled to at least one of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c and 613a to 613c. Note that at least one of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c and 613a to 613c is one or more partial non-edge cores only, partial edge cores only, or one or more partial non-edge cores and one or more partial edge cores.

[0120] Here, the fact that two cores can be magnetically coupled means that when the two cores are excited by an alternating current flowing through the coil provided in the induction heating device, the two cores are magnetically coupled. When no alternating current is flowing through the coil provided in the induction heating device, the two cores are not magnetically coupled. The magnetic coupling of two cores means that spin-spin coupling occurs between the constituent atoms of one core and the constituent atoms of the other core among the two cores. To simply confirm whether the two cores are magnetically coupled or not, in the following cases, the two cores may be regarded as magnetically coupled. That is, when the ratio of the magnetic flux density of the core with a lower magnetic flux density generated in the core to the magnetic flux density of the core with a higher magnetic flux density generated in the core among the two cores is 0.2 or more, the two cores may be regarded as magnetically coupled. The above ratio is the design target of the device determined by the designer during the design of the induction heating device. The above ratio may be 0.2 as described above, but may be 0.3 or more, 0.4 or more, 0.5 or more, or 0.6 or more as required.

[0121] The bridge cores 620a and 620b need to be arranged on the back side of the partial non-edge cores 611a to 611c and on the back side of the partial edge cores 612a to 612c and 613a to 613c. The reason is explained below.

[0122] Even if the bridge cores 620a and 620b are arranged on the side where the conveyance planned surfaces CP of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c and 613a to 613c exist, the bridge cores 620a and 620b can be magnetically coupled to the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c and 613a to 613c. However, when the bridge cores 620a and 620b and the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c and 613a to 613c are arranged in this way, at least a part of the magnetic flux that should penetrate the strip steel sheet 100 penetrates the bridge cores 620a and 620b. As a result, the strip steel sheet 100 cannot be sufficiently heated. Further, when the bridge cores 620a and 620b are arranged on the side surfaces (upstream or downstream side surfaces, or side surfaces in the x-axis direction) of the partial non-edge cores 611a to 611c and the side surfaces (upstream or downstream side surfaces, or side surfaces in the x-axis direction) of the partial edge cores 612a to 612c and 613a to 613c, the degree of magnetic coupling between the bridge cores 620a and 620b and the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c and 613a to 613c becomes relatively small. As a result, the magnetic flux density in the partial non-edge cores 611a and 611c and the partial edge cores 612a to 612c and 613a to 613c, which has become smaller due to the partial non-edge cores 611a and 611c and the partial edge cores 612a to 612c and 613a to 613c being discretized in the x-axis direction, is also less effectively restored to the same level as the magnetic flux density in the partial non-edge core 611b by the bridge cores 620a and 620b. Furthermore, when the bridge cores 620a and 620b are arranged on the side surfaces of the partial non-edge cores 611a to 611c and the side surfaces of the partial edge cores 612a to 612c and 613a to 613c, at least a part of the magnetic flux that should penetrate the strip steel sheet 100 comes to penetrate the bridge cores 620a and 620b. As a result, the strip steel sheet 100 may not be sufficiently heated, and a temperature gradient may easily occur in the strip steel sheet 100 in the width direction (x-axis direction). From the above, the bridge cores 620a and 620b need to be arranged on the back side of the partial non-edge cores 611a to 611c and the back side of the partial edge cores 612a to 612c and 613a to 613c.

[0123] In this embodiment, an example is given where the bridge cores 620a and 620b have soft magnetic ferrite, which is an example of a ferromagnetic material having no anisotropy in the magnetization direction. Further, in this embodiment, an example is given where the bridge core 620a can be magnetically coupled to the partial non-edge cores 611a to 611b and the partial edge cores 612a to 612c, and the bridge core 620b can be magnetically coupled to the partial non-edge cores 611b, 611c and the partial edge cores 613a to 613c. In this case, the partial non-edge core 611a and the partial edge cores 612a to 612c, and the partial non-edge core 611c and the partial edge cores 613a to 613c can also be magnetically coupled through the bridge cores 620a, 620 b and the partial non-edge core 611b. That is, all parts (partial non-edge cores 611a to 611c and partial edge cores 612a to 612c, 613a to 613c) constituting the upper core 610 can be magnetically coupled through the bridge cores 620a and 620b.

[0124] When the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c, 613a to 613c are magnetically coupled through the bridge cores 620a and 620b, the inductance of the induction heating device when the bridge cores 620a and 620b are present is larger than the inductance of the induction heating device when the bridge cores 620a and 620b are not present. Thus, the bridge cores 620a and 620b, the partial non-edge cores 611a to 611b, and the edge cores 612a to 612c, 613a to 613c can be magnetically coupled.

[0125] If the bridge cores 620a and 620b do not exist, the regions between the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c and 613a to 613c (the cooling fins 630a to 630h in this embodiment) will separate the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c and 613a to 613c. Therefore, the magnetic flux density within each partial edge core 612a to 612c and 613a to 613c will decrease. In contrast, in this embodiment, by using the bridge cores 620a and 620b, such a small magnetic flux density can be increased. For example, by using the bridge cores 620a and 620b, the magnetic flux density of each partial edge core 612a to 612c and 613a to 613c can be restored to approximately the same level as the magnetic flux density within the partial non-edge cores 611a to 611b. For example, the magnetic flux density within each partial edge core 612a to 612c and 613a to 613c is preferably 0.75 times or more, and more preferably 0.9 times or more, of the magnetic flux density within the non-edge cores 611a to 611b. However, as described above, it is only necessary that the partial edge cores 612a to 612c and 613a to 613c and the partial non-edge cores 611a to 611b can be magnetically coupled.

[0126] As shown in FIGS. 8 and 9, the bridge cores 620a and 620b are arranged on both sides in the x-axis direction with a gap between them. Also, in FIGS. 8 and 9, the case where the bridge cores 620a and 620b overlap a part of the non-edge core 611 when viewed from the z-axis direction is exemplified. Further, in FIGS. 8 and 9, the case where the bridge cores 620a and 620b overlap at least a part of each of the partial edge cores 612a to 612c and 613a to 613c respectively when viewed from the z-axis direction is exemplified.

[0127] Here, with reference to FIGS. 8 and 9, an example of the arrangement of the bridge cores 620a and 620b in the present embodiment will be described more specifically. The end face (lower face) on the conveyance planned surface CP side of the bridge core 620a is in contact with a part of the back face side (upper face) of the partial non-edge core 611b, the entire end face (upper face) of the back face side of the partial non-edge core 611a arranged on the positive x-axis direction side (one side) with respect to the partial non-edge core 611b, the entire end faces (upper faces) of the back face sides of the partial edge cores 612a to 612c, and the end parts (upper end parts) of the back face sides of the cooling small tubes 640a to 640d. Further, the end face (lower face) on the conveyance planned surface CP side of the bridge core 620b is in contact with a part of the end face (upper face) of the back face side of the partial non-edge core 611b, the entire end face (upper face) of the back face side of the partial non-edge core 611c arranged on the negative x-axis direction side (the other side) with respect to the partial non-edge core 611b, the entire end faces (upper faces) of the back face sides of the partial edge cores 613a to 613c, and the end parts (upper end parts) of the back face sides of the cooling small tubes 640e to 640h.

[0128] However, if the bridge cores 620a and 620b can be magnetically coupled with the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c and 613a to 613c, the bridge cores 620a and 620b do not necessarily have to be in contact with the non-edge core 611, the edge cores 612 and 613, and the cooling small tubes 640a to 640h. For example, the bridge cores 620a and 620b may be arranged in a state of having a gap with the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c and 613a to 613c. Further, the bridge cores 620a and 620b may be in contact with or have a gap and face only one of the non-edge core 611 and the edge cores 612 and 613. Also, the bridge cores 620a and 620b may be in contact with or have a gap and face a part of the region of at least one of the partial edge cores 612a to 612c and 613a to 613c.

[0129] The bridge cores 620a and 620b are preferably arranged as follows. In FIGS. 8 and 9, the plate center side wrap length L of the bridge cores 620a and 620b is the length in the x-axis direction of the overlapping portion of the non-edge core 611 and the edge cores 612 and 613 with the bridge cores 620a and 620b in the region closer to the plate center than the core gap region closest to the plate center among the core gap regions existing at positions facing the bridge cores 620a and 620b when viewed from the z-axis direction. FIGS. 8 and 9 illustrate the case where the region closer to the plate center than the core gap region closest to the plate center among the core gap regions existing at positions facing the bridge cores 620a and 620b is the region of the partial non-edge core 611b.

[0130] The plate center side wrap length L of the bridge cores 620a and 620b is preferably set to be equal to or greater than the length α, and more preferably equal to or greater than the length β. This is because the partial edge cores 612a to 612c and 613a to 613c and the partial non-edge cores 611a to 611c can be surely magnetically coupled through the bridge cores 620a and 620b. For example, in FIGS. 8 and 9, it is preferable that the end portion of the bridge core 620a on the negative x-axis side is arranged at a position on the negative x-axis side with respect to the end portion of the cooling fin 630d on the negative x-axis side so that the wrap length L of the bridge core 620a is equal to or greater than the length α. Further, it is more preferable that the end portion of the bridge core 620a on the negative x-axis side is arranged at a position on the negative x-axis side with respect to the end portion of the cooling fin 630d on the negative x-axis side so that the wrap length L of the bridge core 620a is equal to or greater than the length β.

[0131] The lengths α and β are obtained, for example, from the results of known electromagnetic field analysis (numerical analysis) using mathematical formulas, the finite element method, etc. However, the lengths α and β may be simply determined as follows. That is, among the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c, the minimum value of the x-axis direction length of the cores excluding the partial non-edge core 611b arranged closest to the plate center (that is, the partial non-edge cores 611a, 611c and the partial edge cores 612a to 612c, 613a to 613c) may be defined as the length α, and the maximum value may be defined as the length β. In FIGS. 8 and 9, the cores that overlap with the bridge core 620a when viewed from the z-axis direction are the partial non-edge cores 611a to 611b and the partial edge cores 612a to 612c. The minimum value of the x-axis direction lengths L1 to L4 of the partial non-edge cores 611a and the partial edge cores 612a to 612c excluding the partial non-edge core 611b arranged closest to the plate center among the partial non-edge cores 611a to 611b and the partial edge cores 612a to 612c is the x-axis direction length L3 (= L2 = L1) of the partial non-edge core 611a and the partial edge cores 612b to 612c, and the maximum value thereof is the x-axis direction length L4 of the partial edge core 612a. Therefore, it is preferable that the wrap length L on the plate center side of the bridge core 620a is equal to or greater than the minimum value of the x-axis direction lengths L1 to L4 of the partial non-edge core 611a and the partial edge cores 612a to 612c (that is, the x-axis direction length L3 (= L2 = L1) of the partial non-edge core 611a and the partial edge cores 612b to 612c), and it is more preferable that it is equal to or greater than the maximum value of the x-axis direction lengths L1 to L4 of the partial non-edge core 611a and the partial edge cores 612a to 612c (that is, the x-axis direction length L4 of the partial edge core 612a). Similarly, it is preferable that the wrap length L on the plate center side of the bridge core 620b is equal to or greater than the minimum value of the x-axis direction lengths L1 to L4 of the partial non-edge core 611c and the partial edge cores 613a to 613c (that is, the x-axis direction length L3 (= L2 = L1) of the partial non-edge core 611c and the partial edge cores 613b to 613c), and it is more preferable that it is equal to or greater than the maximum value of the x-axis direction lengths of the partial non-edge core 611c and the partial edge cores 613a to 613c (that is, the x-axis direction length L4 of the partial edge core 613a).

[0132] The length α is the length that forms the lower limit of a preferable range such as the lap length L on the plate center side of the bridge cores 620a and 620b. As a method for simply determining the length α, it has already been described that the minimum value of the length in the x-axis direction of the cores excluding the partial non-edge core 611a (that is, the partial non-edge cores 611b to 611c and the partial edge cores 612a to 612c, 613a to 613c) may be set as α. However, since the length in the x-axis direction of the partial non-edge core 611a is greater than the lengths in the x-axis direction of the partial non-edge cores 611b to 611c and the partial edge cores 612a to 612c, 613a to 613c, it is not necessary to exclude the partial non-edge core 611a when simply determining the length α. For this reason, in the case of the embodiment as shown in FIG. 1 4 In the case of such an embodiment, when simply determining the length α, the minimum value of the lengths in the x-axis direction of the partial cores discrete in the x-axis direction (that is, the partial non-edge cores 611d to 611e and the partial edge cores 612a to 612c, 613a to 613c in FIG. 1 4 may be set as α.

[0133] On the other hand, there is no particular need to stipulate the upper limit value of the lap length L on the plate center side of the bridge cores 620a and 620b.

[0134] Also, in FIGS. 8 and 9, the lap length L' on the plate end side of the bridge cores 620a and 620b is, when viewed from the z-axis direction, the length in the x-axis direction of the overlapping part of the partial edge cores 612a and 613a, which are the partial edge cores arranged most on the plate end side among the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c , 613a to 613c, the bridge cores 620a and 620b. The lap length L' on the plate end side of the bridge cores 620a and 620b is preferably α or more. The lap length L' on the plate end side of the bridge cores 620a and 620b may be, for example, β or more.

[0135] In addition, it is not necessary to prohibit the end portion on the plate end side of the bridge core 620a or 620b from protruding to the plate end side (outer side) beyond the end portion on the plate end side of the partial edge cores 612a and 613a. However, basically, the end portion on the plate end side of the bridge core 620a or 620b does not need to protrude to the plate end side (outer side) beyond the end portion on the plate end side of the partial edge cores 612a and 613a. This is because the effect of improving the magnetic flux density of the core by the portion protruding to the plate end side (the effect of recovering the magnetic flux density in the partial non-edge cores 611a and 611c and the partial edge cores 612a to 612c and 613a to 613c, which became smaller due to the discrete arrangement of the partial non-edge cores 611a, 611c and the partial edge cores 612a to 612c, 613a to 613c in the x-axis direction, to the same level as the magnetic flux density in the partial non-edge core 611b) is relatively small. Here, the plate end side is the side opposite to the plate center side. The end portion on the plate end side of the bridge core 620a and the end portion on the plate end side of the edge core 612a are the end portions on the positive direction side of the x-axis. The end portion on the plate end side of the bridge core 620b and the end portion on the plate end side of the edge core 613 b are the end portions on the negative direction side of the x-axis. On the positive direction side of the x-axis relative to the center in the x-axis direction of the induction heating device, the plate end side is on the positive direction side of the x-axis. On the other hand, on the negative direction side of the x-axis relative to the center in the x-axis direction of the induction heating device, the plate end side is on the negative direction side of the x-axis. a

[0136] In addition, the height (length in the z-axis direction) H of the bridge cores 620a and 620b is preferably 0.5 times or more the smaller of the lengths h and α (the value of the smaller of 0.5×h and 0.5×α). This is because it can surely realize that the partial edge cores 612a to 612c and 613a to 61 3c and the partial non-edge cores 611a to 611c are magnetically coupled via the bridge cores 620a and 620b. Further, the thickness (length in the z-axis direction) H of the bridge cores 620a and 620b is more preferably 1.0 times or more the smaller of the lengths h and α (the value of the smaller of h and α). The partial edge cores 612a to 612c and 613a to 61 3c ​This is because the partial non-edge cores 611a to 611c and the bridge cores 620a, 620b are more strongly magnetically coupled via the bridge cores 620a, 620b. Although there is no particular need to define an upper limit for the thickness (length in the z-axis direction) H of the bridge cores 620a, 620b, it may be set as the larger of 2.0 times the larger of the lengths h, α (the larger value of 2.0×h and 2.0×α) or 1.0 times the smaller of the lengths h, α (the smaller value of h and α).

[0137] Here, as shown in FIGS. 8 to 11, the length h is the length in the z-axis direction of the region on the back side of the coil 220 with respect to the coils 220 arranged in the partial non-edge cores 611a to 611c and the partial edge cores 612a to 6 12c, 613a to 613c among the regions of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 6 12c, 613a to 613c.

[0138] Also, the ratio (=BL / CL) of the length BL in the y-axis direction of the bridge cores 620a, 620b to the length CL in the y-axis direction of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 6 12c, 613a to 613c is preferably 0.2 or more. This is because the magnetic coupling between the partial edge cores 612a to 6 12c, 613a to 613c and the partial non-edge cores 611a to 611c can be surely realized via the bridge cores 620a, 620b. Further, from the viewpoint of strongly magnetically coupling the partial edge cores 612a to 6 12c, 613a to 613c and the partial non-edge cores 611a to 611c via the bridge cores 620a, 620b, the ratio (=BL / CL) of the length BL in the y-axis direction of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 6 12c, 613a to 613c is preferably more than 0.5 or 0.6 or more. Although there is no particular need to define an upper limit for the ratio (=BL / CL), it may be 1.0 or 0.8.

[0139] Also, the positions in the y-axis direction of the upstream ends of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 6 12c, 613a to 613c may coincide with the positions in the y-axis direction of the upstream ends of the bridge cores 620a, 620b (on the negative y-axis direction side). Also, the upstream ends of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 6 12c, 613a to 613c are preferably located upstream of or at the same position as the upstream ends of the bridge cores 620a, 620b. The upstream ends of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 6 12c, 613a to 613c may be located upstream of the upstream ends of the bridge cores 620a, 620b. However, the effect of improving the magnetic flux density of the cores (the effect of recovering the magnetic flux density in the partial non-edge cores 611a, 611c and the partial edge cores 612a to 6 12c, 613a to 613c, which has become smaller due to being discretized in the x-axis direction, to the same level as the magnetic flux density in the partial non-edge core 611b by the bridge cores 620a, 620b) is relatively small. Therefore, it is not necessary for the upstream ends of the bridge cores 620a, 620b to protrude upstream from the upstream ends of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 6 12c, 613a to 613c. Similarly, the upstream ends of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 6The y-axis direction position of the end portions on the downstream side (the positive y-axis direction side) of 12c and 613a to 613c may coincide with the y-axis direction position of the end portions on the downstream side of the bridge cores 620a and 620b. Also, the end portions on the downstream side of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c and 613a to 613c may be located downstream of the end portions on the downstream side of the bridge cores 620a and 620b. The end portions on the downstream side of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c and 613a to 613c may be located upstream of the end portions on the downstream side of the bridge cores 620a and 620b. However, the effect of improving the magnetic flux density of the cores (the effect of recovering the magnetic flux density in the partial non-edge cores 611a, 611c and the partial edge cores 612a to 6 12c, 613a to 613c which has become smaller due to being discretized in the x-axis direction) in the partial non-edge cores 611a, 611c and the partial edge cores 612a to 612c and 613a to 613c is relatively small by the bridge cores 620a and 620b to the same level as the magnetic flux density in the partial non-edge core 611b. Therefore, the end portions on the downstream side of the bridge cores 620a and 620b do not need to protrude downstream from the end portions on the downstream side of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 6 12c, 613a to 613c.

[0140] Also, the end portions on the upstream side of the bridge cores 620a and 620b are not located upstream of the end portions on the upstream side of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 6 12c, 613a to 613c, and the end portions on the downstream side of the bridge cores 620a and 620b are not located downstream of the end portions on the downstream side of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 6 12c, 613a to 613c, the position of the center in the y-axis direction of the bridge cores 620a and 620b may coincide with the position of the center in the y-axis direction of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 6 12c, 613a to 613c.

[0141] When the induction heating device is viewed from the z-axis direction, the bridge cores 620a and 620b do not need to protrude outside the region connecting the end portions (end portions on the plate end side) on both sides in the x-axis direction and the end portions on both the upstream side and the downstream side in the y-axis direction of the partial non-edge cores 611a to 611c and the partial edge cores 612a to 6 12c, 613a to 613c. However, basically, the bridge cores 620a and 620b do not need to protrude outside the region connecting these end portions. This is because the effect of improving the magnetic flux density of the core by the protruding portions of the bridge cores 620a and 620b (the magnetic flux density in the partial non-edge cores 611a and 611c and the partial edge cores 612a to 612c, 613a to 613c, which has become smaller due to the partial non-edge cores 611a and 611c and the partial edge cores 612a to 612c, 613a to 613c being discretized in the x-axis direction, is restored to the same level as the magnetic flux density in the partial non-edge core 611b by the bridge cores 620a and 620 b is relatively small).

[0142] In addition, the values of the lengths of the respective parts of the induction heating device including the lengths h, L1 to L4, BL, and CL are determined as follows, for example. That is, a simulation test or electromagnetic field analysis is performed to simulate the induction heating of the strip steel plate 100 with the induction heating device under a plurality of conditions where the values of the lengths of the respective parts of the induction heating device are different. Then, from the results in which a desired temperature distribution is obtained as the temperature distribution in the x-axis direction of the strip steel plate 100 in the results of the simulation test or electromagnetic field analysis, the values of the lengths of the respective parts of the induction heating device are determined. When there is a part of the induction heating device that is restricted in length due to installation space or the like, the value of the length of that part is determined to satisfy the restriction. For example, the size, shape, and position of the bridge cores 620a and 620b are determined so as not to affect the movement of other members such as the coil 220 and the shield plates 2 3 0a, 2 3 0b, etc.

[0143] As described above, this embodiment exemplifies the case where the bridge cores 620a and 620b are separate cores from the upper core 610 (non-edge core 611 and edge cores 612 and 613). Therefore, as shown in FIGS. 7 to 9, boundary lines exist at the boundaries between the bridge cores 620a and 620b and the upper core 610 (non-edge core 611 and edge cores 612 and 613). In addition, among the respective parts of the upper inductor 600 in the above description, the shield plates 2 3 0a, 2 3 It is preferable that the positions of the parts other than 0b are fixed.

[0144] Similar to the upper inductor 600, the lower inductor 700 also includes a lower core 710 having a non-edge core 711 (partial non-edge cores 711a to 711c) and edge cores 712 to 713 (partial edge cores 712a to 712c, 713a to 713c), bridge cores 720a and 720b, a coil 320, shield plates 330a to 330b, cooling fins 730a to 730h, and cooling small tubes 740a to 740h, and has the same configuration as the upper inductor 600. In this embodiment, the case is exemplified where cores arranged in pairs for each one coil constituting a pair of coils are configured by the upper core 610 and the lower core 710. Further, in this embodiment, the case is exemplified where the cores constituting a set of cores have the upper core 610 and the lower core 710.

[0145] As described above, in this embodiment, the bridge cores 620a, 620b, 720a, and 720b can increase the range and amount of the main magnetic flux passing through the partial non-edge cores 611a to 611c, 711a to 711c, and the partial edge cores 612a to 612c, 613a to 613c, 712a to 712c, 713a to 713c compared to the case where the bridge cores 620a, 620b, 720a, and 720b are not present. Therefore, the partial non-edge cores 611a to 611c, 711a to 711c, and the partial edge cores 612a to 612c, 613a to 613c, 712a to 712c, 713a to 713c can be efficiently magnetically coupled.

[0146] As described above, the non-edge cores 611 and the edge cores 612 and 613 (partial non-edge cores 611a to 611c and partial edge cores 612a to 612c, 613a to 613c) can be magnetically coupled by the bridge cores 620a and 620b. Therefore, the magnetic coupling (spin-spin coupling) among the partial non-edge cores 611a to 611c, the partial edge cores 612a to 612c, 613a to 613c, and the bridge cores 620a and 620b can be increased. As a result, the magnetic flux density in the partial non-edge cores 611a to 611c and the magnetic flux density in the partial edge cores 612a to 612c, 613a to 613c can be made higher than in the case where the bridge cores 620a and 620b are not provided. The above is the same for the lower inductor 7 00.

[0147] In Patent Document 6, screen14 is composed of a conductor. Magnetic pad16 is disposed on armature15 that supports screen14. Therefore, even if magnetic pad16 is a ferromagnetic material, screen14 (conductor) exists between magnetic bars8 and magnetic pad16. Thus, magnetic bars8 and magnetic pad16 are not magnetically coupled. That is, magnetic pad16 does not have the function as the bridge core described in this embodiment. Also, since magnetic pad16 is not located on the back side of the core, it does not have the function as the bridge core described in this embodiment.

[0148] Further, the armature 12 is for positioning the magnetic bar 8 and is not a core that magnetically couples with the magnetic bar 8. Even if the armature 12 is a ferromagnetic material, due to its thin thickness, the magnetic resistance of the armature 12 becomes extremely high. That is, even if the main magnetic flux passing through the magnetic bar 8 attempts to pass through the armature 12, the armature 12 becomes magnetically saturated and is equivalent to a non-magnetic material. Thus, the armature 12, even if it is a ferromagnetic material, is equivalent to a non-magnetic material and is not magnetically coupled with the magnetic bar 8. That is, the armature 12 does not have the function as a bridge core described in this embodiment. Also, since the armature 12 is not located on the back side of the core, it does not have the function as a bridge core described in this embodiment.

[0149] Also, in the technology of Patent Document 6, the plurality of magnetic bars 8 are arranged with intervals. For this reason, the alternating magnetic field enlarged by the plurality of magnetic bars 8 leaks from the region between the plurality of magnetic bars 8 and diffuses to the surroundings. There is a risk that the surrounding objects (for example, electronic devices) may be heated by the alternating magnetic field diffused from the plurality of magnetic bars 8. Also, there is a risk that noise may be generated in the surrounding objects due to the alternating magnetic field diffused from the plurality of magnetic bars 8. Also, there is a risk that the strip steel plate 100 may be heated unintentionally by the alternating magnetic field diffused from the plurality of magnetic bars 8. In this case, there is a risk that the temperature distribution of the strip steel plate 100 in the x-axis direction becomes non-uniform. Since the places where the induction heating device is installed are not under the same conditions, it is substantially impossible to predict whether the strip steel plate 100 will be heated unintentionally. If the total power of the induction heating device increases due to the unintentional heating of the strip steel plate 100, there is a risk of causing a decrease in the heating efficiency of the entire induction heating device. In this case, there is a risk that the method of power supply to the induction heating device has to be reviewed in order to heat the strip steel plate 100 to a desired temperature.

[0150] In contrast, in the present embodiment, the bridge cores 620a and 620b enable magnetic coupling between the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c, 613a to 613c. Therefore, it is possible to suppress the diffusion of the alternating magnetic field increased by the cores (the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c, 613a to 613 c ) to the surroundings. Thus, various adverse effects described above can be suppressed.

[0151] Furthermore, in the present embodiment, the bridge cores 620a and 620b are made of soft magnetic ferrite (a ferromagnetic material having no anisotropy in the magnetization direction). Therefore, the bond between the spins of the constituent atoms between the partial non-edge cores 611a to 611c and the partial edge cores 612a to 612c, 613a to 613c and the bridge cores 620a and 620b can be further promoted. Thus, the magnetic flux density in the non-edge core 611 and the edge cores 612 to 613 can be increased.

[0152] Also, in the present embodiment, the cooling fins 630a to 630h and the cooling small tubes 640a to 640h can suppress the temperature rise of the partial non-edge cores 611a to 611c and the temperature rise of the partial edge cores 612a to 612c, 613a to 613c.

[0153] Also, in the present embodiment, the bridge cores 620a and 620b are cores different from the upper core 610. Therefore, the assembly work and maintenance work of the induction heating device can be facilitated. Also, if the overall shape and size are the same, the same bridge cores 620a and 620b can be applied to induction heating devices of different specifications (for example, induction heating devices having different numbers of partial non-edge cores and / or partial edge cores). The above also applies to the lower inductor 700.

[0154] <Modification Example> In this embodiment, the case where the bridge cores 620a and 620b are made of soft magnetic ferrite is exemplified. However, the soft magnetic material constituting the bridge cores 620a and 620b is not limited to soft magnetic ferrite. For example, the bridge cores 620a and 620b may be composed of a plurality of electromagnetic steel sheets having the same planar shape (rectangular shape in the example of this embodiment) as the shape of the plane parallel to the x-y plane of the bridge cores 620a and 620b, and laminated in the z-axis direction. Also, the bridge cores 620a and 620b may be composed of a plurality of electromagnetic steel sheets having the same planar shape as the shape of the plane parallel to the y-z plane of the bridge cores 620a and 620b, and laminated in the x-axis direction.

[0155] Also, in this embodiment, the case where the number of cooling fins 630a to 630h and the number of cooling small tubes 640a to 640h are each eight are exemplified. However, these numbers are not limited to eight. Also, the intervals between the cooling fins 630a to 630h and the intervals between the cooling small tubes 640a to 640h do not necessarily have to be the same. By increasing the number of the cooling fins 630a to 630h and the cooling small tubes 640a to 640h arranged in the region of the non-edge core 611 (between the partial non-edge cores 611a to 611c), the region of the edge cores 612 and 613 (between the partial edge cores 612a to 612c and 613a to 613c), and the region between the non-edge core 611 and the edge cores 612 and 613 (between the partial non-edge core 611a and the partial edge core 612c and between the partial non-edge core 611c and the partial edge core 612c), the cooling effect of the non-edge core 611 and the edge cores 612 and 613 is enhanced. That is, the number of the cooling fins 630a to 630h and the number of the cooling small tubes 640a to 640h are not limited to the numbers shown in FIGS. 7 to 9, and are appropriately determined according to the temperature required for the induction heating device.

[0156] Also, in this embodiment, the case where the number of the bridge cores 620a and 620b provided in the upper inductor 600 is two is exemplified. However, the number of the bridge cores provided in the upper inductor 600 is not limited to two. The upper inductor 600 may be provided with one bridge core or three or more bridge cores.

[0157] For example, as shown in FIG. 12, at least a partial region of the end face (upper face) on the back side of each of the partial non-edge cores 611a to 611c, and at least a partial region of the end face (upper face) on the back side of each of the partial edge cores 612a to 612c and 613a to 613c face at least a partial region of the end face (lower face) on the conveyance planned surface CP side of the bridge core 620c, and one bridge core 620c may be arranged. Also in the lower inductor 700, at least a partial region of the end face (lower face) on the back side of each of the partial non-edge cores 711a to 711c, and at least a partial region of the end face (lower face) on the back side of each of the partial edge cores 712a to 712c and 713a to 713c face at least a partial region of the end face (upper face) on the conveyance planned surface CP side of the bridge core 720c, and one bridge core 720c may be arranged.

[0158] Note that FIG. 12 is a figure corresponding to FIG. 9. In FIG. 12, the case where the end face (lower face) on the conveyance planned surface CP side of the bridge core 620c contacts all regions of the end face (upper face) on the back side of the partial non-edge cores 611a to 611c and all regions of the end face (upper face) on the back side of the partial edge cores 612a to 612c and 613a to 613c is illustrated. Similarly, in FIG. 12, the case where the end face (upper face) on the conveyance planned surface CP side of the bridge core 720c contacts all regions of the end face (lower face) on the back side of the partial non-edge cores 711a to 711c and all regions of the end face (lower face) on the back side of the partial edge cores 712a to 712c and 713a to 713c is illustrated. As described above, the bridge cores 620c and 720c do not need to be in contact with these partial non-edge cores as long as they can be magnetically coupled to the partial non-edge cores 611a to 611c, 711a to 711c and the partial edge cores 612a to 612c, 613a to 613c, 712a to 712c, 713a to 713c.

[0159] Further, in the present embodiment, when the shielding plates 230a and 230b move to the position closest to the center position in the x-axis direction of the induction heating device within the movable range of the shielding plates 230a and 230b in the x-axis direction, among the core gap regions existing at the positions facing the bridge cores 620a and 620b, the end portions on the plate center side of the core gap region closest to the plate center side (the end portions on the plate center side of the cooling fins 630d and 630h in the examples shown in FIGS. 8 and 9) are arranged inside (on the plate center side) of the end portions on the plate center side of the shielding plates 230a and 230b. However, the positional relationship between the shielding plates 230a and 230b when the shielding plates 230a and 230b move to the position closest to the center position in the x-axis direction of the induction heating device within the movable range of the shielding plates 230a and 230b in the x-axis direction, and the non-edge core 611 and the edge cores 612 and 613 is not limited to such a relationship.

[0160] For example, when the shielding plates 230a and 230b move to the position closest to the center position in the x-axis direction of the induction heating device within the movable range of the shielding plates 230a and 230b in the x-axis direction, the end portions on the plate center side of at least one of the partial edge cores 612a to 612c and 613a to 613c may be respectively arranged inside (on the plate center side) of the end portions on the plate center side of the shielding plates 230a and 230b. For example, the partial edge cores 612a to 612c and 613a to 613c may be respectively arranged inside (on the plate center side) of the end portions on the plate center side of the shielding plates 230a and 230b.

[0161] When the shielding plates 230a and 230b move to the position closest to the center position in the x-axis direction of the induction heating device within the movable range of the shielding plates 230a and 230b in the x-axis direction, at least one end portion on the plate center side of the cooling fins 630a to 630d and at least one end portion on the plate center side of the cooling fins 630e to 630h may be arranged inside (on the plate center side) of the end portions on the plate center side of the shielding plates 230a and 230b.

[0162] For example, when the shielding plates 230a and 230b move to the position closest to the center position of the induction heating device in the x-axis direction within the movable range of the shielding plates 230a and 230b in the x-axis direction, the end portions on the plate center side of the cooling fins 630d and 630h may be arranged inside (on the plate center side) of the end portions on the plate center side of the shielding plates 230a and 230b. Also, the end portions on the plate center side of the cooling fins 630a to 630d and 630e to 630h may each be arranged inside (on the plate center side) of the end portions on the plate center side of the shielding plates 230a and 230b. Also, the end portions on the plate center side of the cooling fins 630b to 630d and 630f to 630h may each be arranged inside (on the plate center side) of the end portions on the plate center side of the shielding plates 230a and 230b. Also, when the shielding plates 230a and 230b move to the position closest to the center position of the induction heating device in the x-axis direction within the movable range of the shielding plates 230a and 230b in the x-axis direction, at least one end portion on the plate center side of the cooling fins 630a to 630d and at least one end portion on the plate center side of the cooling fins 630e to 630h may each be arranged outside (on the plate end side) of the end portions on the plate center side of the shielding plates 2 3 0a, 2 3 0b on the plate center side.

[0163] Also, the cooling members arranged between the partial non-edge cores 611a to 611c, the cooling members arranged between the partial edge cores 612a to 612c and 613a to 613c, and the cooling members arranged between the partial edge cores 612c, 613c and the partial non-edge cores 611a, 611c do not necessarily have to be the cooling fins 630a to 630h and the cooling small tubes 640a to 640h as long as they are made of a non-magnetic conductor configured to be capable of cooling. For example, a hollow rectangular parallelepiped-shaped pipe made of a non-magnetic conductor may be arranged in the region where the cooling fins 630a to 630h and the cooling small tubes 640a to 640h are arranged. In this case, cooling water may be supplied to the hollow portion of the pipe.

[0164] Further, cooling members may not be disposed in the regions between the partial non-edge cores 611a to 611c, the regions between the partial edge cores 612a to 612c and 613a to 613c, and the regions between the partial edge cores 612c and 613c and the partial non-edge cores 611a and 611c. The regions between the partial non-edge cores 611a to 611c, the regions between the partial edge cores 612a to 612c and 613a to 613c, and the regions between the partial edge cores 612c and 613c and the partial non-edge cores 611a and 611c may be voids. In such a case, cooling gas may be supplied as a cooling medium to the voids. Further, by making the length of the void region in the x-axis direction longer than the lengths shown in FIGS. 8 and 9, the cooling effect by air cooling may be enhanced.

[0165] Note that the number of partial non-edge cores may be two or more and is not limited. However, it is preferable that all of the partial non-edge cores can be magnetically coupled to at least one of the bridge cores. More preferably, all of the partial non-edge cores can be magnetically coupled to each other. Further, the shapes and sizes of the plurality of partial non-edge cores are not limited. The shapes and sizes of the plurality of partial non-edge cores may be the same or different. Also, for the plurality of partial edge cores, the shapes and sizes may be the same or different.

[0166] For example, the induction heating device may be configured as shown in FIGS. 13 to 17. FIG. 13 is a diagram showing an example of the external configuration of the induction heating device. FIG. 13 is a diagram corresponding to FIG. 7. FIG. 14 is a diagram showing an example of a first cross section of the induction heating device. Specifically, FIG. 14 is a cross-sectional view taken along line I-I of FIG. 13 and is a diagram corresponding to FIG. 8. FIG. 15 is a diagram showing an example of a second cross section of the induction heating device. Specifically, FIG. 15 is a cross-sectional view taken along line II-II of FIG. 13 and is a diagram corresponding to FIG. 9. FIG. 16 is a diagram showing an example of a third cross section of the induction heating device. Specifically, FIG. 16 is a cross-sectional view taken along line III-III of FIG. 13. FIG. 17 is a diagram showing an example of a fourth cross section of the induction heating device. Specifically, FIG. 17 is a cross-sectional view taken along line IV-IV of FIG. 13.

[0167] In FIGS. 13 to 17, the upper inductor 600 includes an upper core 610, a bridge core 620c, a coil 220, and shield plates 230a and 230b. In the example shown in FIGS. 13 to 17, the non-edge core 611 has a plurality of partial non-edge cores 611d to 611e arranged at intervals in the x-axis direction. Further, the edge cores 612 and 613 each have a plurality of partial edge cores 612d to 612e and 613d to 613e arranged at intervals in the x-axis direction.

[0168] The difference between the partial non-edge cores 611d to 611e and the partial non-edge cores 611a to 611c shown in FIGS. 8 and 9 is only the length in the x-axis direction. The non-edge cores 611d to 611e are, for example, a plurality of electromagnetic steel sheets laminated in the x-axis direction and are composed of a plurality of electromagnetic steel sheets having the same thickness and the same planar shape. In this case, the number of laminated electromagnetic steel sheets constituting the partial non-edge cores 611d to 611e is different from the number of laminated electromagnetic steel sheets constituting the partial non-edge cores 611a to 611c. Also, in the example shown in FIG. 13, when the partial non-edge cores 611d to 611e are composed of a plurality of electromagnetic steel sheets having the same thickness and the same planar shape, the number of laminated electromagnetic steel sheets in each case is the same.

[0169] As shown in Fig. 16, the y-z cross-section of the partial non-edge cores 611d to 611e is the same as the y-z cross-section of the non-edge core 211 shown in Fig. 4. Also, as shown in Fig. 16, the partial non-edge cores 611d to 611e have a central leg portion 6111 and a body portion 6112. The difference between the central leg portion 6111 of the partial non-edge cores 611d to 611e and the central leg portion 2111 of the partial non-edge cores 611a to 611c is only the length in the x-axis direction. Similarly, the difference between the body portion 6112 of the partial non-edge cores 611d to 611e and the body portion 2112 of the partial non-edge cores 611a to 611c is only the length in the x-axis direction. Incidentally, as described above, an example of the central leg portion 2111 and the body portion 2112 of the partial non-edge cores 611a to 611c is shown in Fig. 4. Also, in Figs. 12 to 16, the case where the shapes and sizes of the plurality of partial non-edge cores 611d to 611e are the same is illustrated.

[0170] The differences between the partial edge cores 612d to 612e, 613d to 613e and the partial edge cores 612a to 612c, 613a to 613c shown in Figs. 8 and 9 are only the lengths in the x-axis direction. The partial edge cores 612d to 612e, 613d to 613e are, for example, a plurality of electromagnetic steel sheets laminated in the x-axis direction and are composed of a plurality of electromagnetic steel sheets having the same thickness and the same planar shape. In this case, the number of laminated electromagnetic steel sheets constituting the partial edge cores 612d to 612e, 613d to 613e is different from the number of laminated electromagnetic steel sheets constituting the partial edge cores 612a to 612c, 613a to 613c. Also, in the example shown in Fig. 13, when the partial edge cores 612d to 612e are composed of a plurality of electromagnetic steel sheets having the same thickness and the same planar shape, the number of laminated electromagnetic steel sheets in each case is the same.

[0171] As shown in Fig. 17, the y-z cross-sections of the partial edge cores 612d to 612e and 613d to 613e are the same as the y-z cross-section of the edge core 212 shown in Fig. 5. Also, as shown in Fig. 17, the partial edge cores 612d to 612e have a central leg 6121, an upstream leg 6122, a downstream leg 6123, and a body portion 6124. The differences between the central leg 6121, the upstream leg 6122, and the downstream leg 6123 of the partial edge cores 612d to 612e and the central leg 2121, the upstream leg 2122, and the downstream leg 2123 of the partial edge cores 612a to 612c are only the lengths in the x-axis direction. Similarly, the difference between the body portion 6124 of the partial edge cores 612d to 612e and the body portion 2124 of the partial edge cores 612a to 612c is only the length in the x-axis direction. Incidentally, as described above, an example of the central leg 2121, the upstream leg 2122, the downstream leg 2123, and the body portion 2124 of the partial edge cores 612a to 612c is shown in Fig. 5. Also, Figs. 12 to 15 and 17 illustrate cases where the shapes and sizes of the plurality of partial edge cores 612d to 612e and 613d to 613e are the same.

[0172] Also, Figs. 13 to 17 illustrate cases where the lengths in the x-axis direction and the intervals of all the partial non-edge cores 611d to 611e and all the partial edge cores 612d to 612e and 613d to 613e are the same.

[0173] The bridge core 620c is a ferromagnetic material for magnetically coupling at least one core among the partial non-edge cores 611d to 611e and the partial edge cores 612d to 612e, 613d to 613e. Note that the bridge core 620c itself is the same as the bridge core 620c shown in FIG. 12. FIGS. 13 to 17 illustrate a case where the end face (lower face) on the conveyance planned surface CP side of the bridge core 620c faces the entire end faces (upper faces) on the back side of all the partial non-edge cores 611d to 611e and the entire end faces (upper faces) on the back side of all the partial edge cores 612d to 612e, 613d to 613e with a gap therebetween. The gap between the bridge core 620c and the partial non-edge cores 611d to 611e and the partial edge cores 612d to 612e, 613d to 613e is determined such that the bridge core 620c can magnetically couple with at least one core of the partial non-edge cores 611d to 611e.

[0174] Similar to the upper inductor 600, the lower inductor 700 includes a lower core 710 having a non-edge core 711 (partial non-edge cores 711d to 711e) and two edge cores 712, 713 (partial edge cores 712d to 712e, 713d to 713e), a bridge core 720c, a coil 320, and shield plates 330a, 330b, and has the same configuration as the upper inductor 600. Therefore, as shown in FIG. 16, the partial non-edge cores 711d to 711e have a central leg portion 7111 and a body portion 7112. Also, as shown in FIG. 17, the partial edge cores 712d to 712e have a central leg portion 7121, an upstream leg portion 7122, a downstream leg portion 7123, barrel portion and 7124.

[0175] In addition, as described in this embodiment, cooling members (for example, cooling fins and cooling small tubes) may be disposed between two adjacent partial non-edge cores having a gap in the x-axis direction, between two adjacent partial edge cores having a gap in the x-axis direction, and between a partial non-edge core and a partial edge core having a gap in the x-axis direction. Further, as described in this embodiment, the upper core 610 and the lower core 710 may be in contact with the bridge cores 620c and 720c, respectively.

[0176] In addition, various modifications described in the first embodiment may be adopted in the induction heating apparatus of this embodiment. Further, a modification combining at least two of the above-described modifications including the modification described in the first embodiment may be adopted in the induction heating apparatus of this embodiment. In addition, each of the above-described modifications may be adopted in the lower inductor 700.

[0177] (Third Embodiment) Next, a third embodiment of the present invention will be described. In the second embodiment, the case where the upper core 610 (non-edge core 611 and edge cores 612 and 613) and the bridge cores 620a and 620b are separate cores is illustrated. Similarly, the case where the lower core 710 (non-edge core 711 and edge cores 712 and 713) and the bridge cores 720a and 720b are separate cores is illustrated. In contrast, in this embodiment, the case where the upper core and the bridge core, and the lower core and the bridge core are integrated into one core is illustrated. As described above, the core configurations are mainly different between this embodiment and the first embodiment. Therefore, in the description of this embodiment, the same parts as those in the first and second embodiments will be denoted by the same reference numerals as those in FIGS. 1 to 17, and detailed description thereof will be omitted.

[0178] FIG. 18 is a diagram showing an example of the external configuration of the induction heating apparatus. FIG. 18 corresponds to FIGS. 1 and 7. The induction heating device shown in Fig. 18 includes an upper inductor 1300 and a lower inductor 1400. The upper inductor 1300 and the lower inductor 1400 are arranged at positions facing each other via the planned conveyance surface CP of the strip steel 100 (see Figs. 19 to 25). The upper inductor 1300 and the lower inductor 1400 have the same configuration. Therefore, here, the upper inductor 1300 will be described in detail, and the detailed description of the lower inductor 1400 will be omitted as necessary. Note that the distance between the upper inductor 1300 and the planned conveyance surface CP and the distance between the lower inductor 1400 and the planned conveyance surface CP may or may not be the same. In this embodiment as well as in the first and second embodiments, a case where the induction heating device has a shape with a mirror-symmetric relationship with the y-z plane at the center in the x-axis direction of the induction heating device as the symmetry plane is exemplified. Further, when the distance between the upper inductor 1300 and the strip steel 100 and the distance between the lower inductor 1400 and the strip steel 100 are the same, the induction heating device has a shape with a mirror-symmetric relationship with the x-y plane at the center in the z-axis direction of the induction heating device as the symmetry plane.

[0179] Fig. 19 is a diagram showing an example of a first cross section of the induction heating device. Specifically, Fig. 19 is a cross-sectional view taken along line I-I of Fig. 18 and corresponds to Fig. 8. Fig. 20 is a diagram showing an example of a second cross section of the induction heating device. Specifically, Fig. 20 is a cross-sectional view taken along line II-II of Fig. 18 and corresponds to Fig. 9. Fig. 21 is a diagram showing an example of a third cross section of the induction heating device. Specifically, Fig. 21 is a cross-sectional view taken along line III-III of Fig. 18 and corresponds to Fig. 10. Fig. 22 is a diagram showing an example of a fourth cross section of the induction heating device. Specifically, Fig. 22 is a cross-sectional view taken along line VI-VI of Fig. 18. Fig. 23 is a diagram showing an example of a fifth cross section of the induction heating device. Specifically, Fig. 23 is a cross-sectional view taken along line V-V of Fig. 18 and corresponds to Fig. 11. Fig. 24 is a diagram showing an example of a sixth cross section of the induction heating device. Specifically, Fig. 24 is a cross-sectional view taken along line VI-VI of Fig. 18. Fig. 25 is a diagram showing an example of a seventh cross section of the induction heating device. Specifically, Fig. 25 is a cross-sectional view taken along line VII-VII of Fig. 18.

[0180] In FIGS. 18 to 20, the upper inductor 1300 includes an upper core 1310, a coil 220, shield plates 230a to 230b, cooling fins 630a to 630h, and cooling small tubes 640a to 640h.

[0181] The upper core 1310 is formed by integrating the partial non-edge cores 611a to 611c, the partial edge cores 612a to 612c, and 613a to 613c described in the second embodiment into one core. In this embodiment, a case is exemplified in which the upper core 1310 is composed of a plurality of electromagnetic steel sheets laminated in the x-axis direction and the plurality of electromagnetic steel sheets have the same thickness.

[0182] In FIGS. 19 to 20, regions 1311a and 1311b of the upper core 1310 are regions including regions corresponding to the bridge cores 620a and 620b of the second embodiment among the regions of the upper core 1310. In this embodiment, the planar shape of the electromagnetic steel sheets arranged in regions 1311a and 1311b of the upper core 1310 is, for example, like the regions of the upper core 1310 shown in FIGS. 21 to 25.

[0183] As shown in FIG. 21, in regions 1311a and 1311b of the upper core 1310, in regions adjacent in the z-axis direction to the regions where the cooling fins 630a to 630c, 630e to 630g and the cooling small tubes 640a to 640c, 640e to 640g are arranged, for example, electromagnetic steel sheets having a planar shape corresponding to the regions are laminated in the x-axis direction. The y-z cross section of the region is, for example, like the y-z cross section of the upper core 1310 shown in FIG. 21. In FIG. 21, a case is exemplified in which the outer shape of the entire y-z cross section of the region is rectangular. Also, in FIG. 21, a case is exemplified in which the length of the rectangle in the z-axis direction is the same as the length of the bridge cores 620a and 620b in the z-axis direction of the second embodiment. However, the length of the rectangle in the z-axis direction may be (slightly) different for each position in the x-axis direction according to the curvature of the cooling small tubes 640a to 640c, 640e to 640g, for example.

[0184] Also, as shown in FIG. 22, in regions 1311a and 1311b of the upper core 1310, electromagnetic steel sheets having a planar shape corresponding to the regions where the partial edge cores 612a to 612c and 613a to 613c of the second embodiment are arranged are laminated in the x-axis direction. The y-z cross-section of the region is, for example, the same as the y-z cross-section of the upper core 1310 shown in FIG. 22. In FIG. 22, a case where the outer shape of the entire y-z cross-section of the region is E-shaped is illustrated (however, the lengths of the horizontal lines of E are all the same). Also, in FIG. 22, a case where the length in the z-axis direction of the region (the length in the direction parallel to the horizontal line of E) is the sum of the lengths in the z-axis direction of the bridge cores 620a and 620b of the second embodiment and the lengths in the z-axis direction of the partial edge cores 612a to 612c and 613a to 613c of the second embodiment is illustrated.

[0185] FIG. 22 shows an example of a region 13121 corresponding to the central leg 2121 of the partial edge core 612c of the second embodiment, a region 13122 corresponding to the upstream leg 2122, a region 13123 corresponding to the downstream leg 2123, and a region region 1 3124 corresponding to the body 2124, and a region 13120 corresponding to the bridge core 620a of the second embodiment. Similarly, FIG. 22 shows an example of a region 14121 corresponding to the central leg 3121 of the partial edge core 712c of the second embodiment, a region 14122 corresponding to the upstream leg 3122, a region 14123 corresponding to the downstream leg 3123, and the body 3 124 corresponding to the region region 1 4124, and a region 14120 corresponding to the bridge core 720a of the second embodiment.

[0186] Also, as shown in FIG. 23, in regions 1311a and 1311b of the upper core 1310, in regions adjacent in the z-axis direction to the regions where the cooling fins 630d and 630h and the cooling small tubes 640d and 640h are arranged, for example, electromagnetic steel sheets having a planar shape corresponding to the regions are laminated in the x-axis direction. The y-z cross section of the region is, for example, like the y-z cross section of the upper core 1310 shown in FIG. 23. In FIG. 23, a case where the outer shape of the entire y-z cross section of the region is rectangular is illustrated. In FIG. 23, a case where the length in the z-axis direction of the rectangle is the same as the length in the z-axis direction of the bridge cores 620a and 620b of the second embodiment is illustrated. However, the length in the z-axis direction of the rectangle may be (slightly) different for each position in the x-axis direction according to the curvature of the cooling small tubes 640d and 640h, for example.

[0187] Also, as shown in FIG. 24, in regions 1311a and 1311b of the upper core 1310, in the regions where the partial non-edge cores 611a to 611c of the second embodiment are arranged, for example, electromagnetic steel sheets having a planar shape corresponding to the regions are laminated in the x-axis direction. The region is, for example, the region of the upper core 1310 shown in FIG. 24. In FIG. 24, a case where the outer shape of the entire y-z cross section of the region is T-shaped is illustrated. In FIG. 24, a case where the length in the z-axis direction of the region (the length in the direction parallel to the vertical line of T) is the sum of the length in the z-axis direction of the bridge cores 620a and 620b of the second embodiment and the length in the z-axis direction of the partial edge cores 612a to 612c and 613a to 613c of the second embodiment is illustrated.

[0188] FIG. 24 shows an example of a region 13111 corresponding to the central leg portion 2111 of the partial non-edge core 611b of the second embodiment, a region region 1 3112 corresponding to the body portion 2112, and a region 13120 corresponding to the bridge core 620a of the second embodiment. Similarly, FIG. 4 shows an example of a region 14111 corresponding to the central leg portion 3111 of the partial non-edge core 711b of the second embodiment, a region region 1 4112 corresponding to the body portion 3112, and a region 14120 corresponding to the bridge core 720a of the second embodiment.

[0189] On the one hand, in FIGS. 19 to 20, the region 1312 of the upper core 1310 is a region that does not include the region corresponding to the bridge cores 620a and 620b of the second embodiment in the z-axis direction among the regions of the upper core 1310. In the region 1312 of the upper core 1310, for example, electromagnetic steel sheets having the same planar shape corresponding to the region 1312 are laminated in the x-axis direction. The y-z cross section of the region 1312 of the upper core 1310 is, for example, like the y-z cross section of the upper core 1310 shown in FIG. 25. In FIG. 25, a case where the outer shape of the entire y-z cross section of the region 1312 of the upper core 1310 is T-shaped is illustrated. Also, in FIG. 25, a case where the length of the region 1312 of the upper core 1310 in the z-axis direction (the length in the direction parallel to the vertical line of T) is the same as the length of the partial non-edge cores 611a to 611c of the second embodiment in the z-axis direction is illustrated.

[0190] FIG. 25 shows an example of a region 13111 corresponding to the central leg portion 2111 of the partial non-edge core 611b of the second embodiment, a region 13112 corresponding to the body portion 2112, and a region 13120 corresponding to the bridge core 620a of the second embodiment. Similarly, FIG. region 1 2 shows an example of a region 14111 corresponding to the central leg portion 3111 of the partial non-edge core 711b of the second embodiment, a region 14112 corresponding to the body portion 3112, and a region 14120 corresponding to the bridge core 720a of the second embodiment. Note that FIG. 24 is a y-z cross section of a region adjacent to the regions corresponding to the bridge cores 620a and 620b in the z-axis direction among the regions corresponding to the partial non-edge core 611b of the second embodiment. On the other hand, FIG. 25 is a y-z cross section of a region not adjacent to the regions corresponding to the bridge cores 620a and 620b in the z-axis direction among the regions corresponding to the partial non-edge core 611b of the second embodiment. 5 In FIG. 2, there is shown an example of a region 14111 corresponding to the central leg portion 3111 of the partial non-edge core 711b of the second embodiment, a region 14112 corresponding to the body portion 3112, and a region 14120 corresponding to the bridge core 720a of the second embodiment. region 1 FIG. 2 shows an example of a region 14111 corresponding to the central leg portion 3111 of the partial non-edge core 711b of the second embodiment, a region 14112 corresponding to the body portion 3112, and a region 14120 corresponding to the bridge core 720a of the second embodiment. Incidentally, FIG. 24 is a y-z cross section of a region adjacent to the regions corresponding to the bridge cores 620a and 620b in the z-axis direction among the regions corresponding to the partial non-edge core 611b of the second embodiment. On the other hand, FIG. 25 is a y-z cross section of a region not adjacent to the regions corresponding to the bridge cores 620a and 620b in the z-axis direction among the regions corresponding to the partial non-edge core 611b of the second embodiment.

[0191] The plurality of electromagnetic steel sheets constituting the upper core 1310 are fixed so as not to separate from each other. The method of fixing the plurality of electromagnetic steel sheets is not limited. For example, various known methods such as fixing with an adhesive, fixing by welding, caulking, and fixing using a fixing member are adopted as the method of fixing the plurality of electromagnetic steel sheets. As described above, in this embodiment, the upper core (non-edge core and edge core) and the bridge core are an integrated one core. Therefore, as shown in FIGS. 18 to 20, there is no boundary line at the boundary between the bridge core (regions corresponding to the bridge cores 620a and 620b) and the non-edge core and edge core (regions corresponding to the non-edge core 611 and the edge cores 612 and 613). For convenience of notation, in FIGS. 18 to 20, the illustration of the boundary lines of the individual electromagnetic steel sheets is omitted.

[0192] In this embodiment, a case where the bridge cores are constituted by the regions corresponding to the bridge cores 620a, 620b, 720a, and 720b among the regions of the upper core 1310 and the lower core 1410 is exemplified.

[0193] The lower inductor 1400 also includes a lower core 1410, a coil 320, shield plates 330a and 330b, cooling fins 730a to 730h, and cooling small tubes 740a to 740h, similar to the upper inductor 1300, and has the same configuration as the upper inductor 1300. In FIGS. 19 to 20, the regions 1411a and 1411b of the lower core 1410 are regions including the regions corresponding to the bridge cores 720a and 720b of the second embodiment among the regions of the lower core 1410. On the other hand, in FIGS. 19 to 20, the region 1412 of the lower core 1410 is a region that does not include the regions corresponding to the bridge cores 720a and 720b of the second embodiment among the regions of the lower core 1410.

[0194] As described above, in this embodiment, the regions corresponding to the bridge cores 620a to 620b and 720a to 720b and the regions corresponding to the non-edge cores 611 and 711 and the edge cores 612 to 613 and 712 to 713 are integrated without separation. That is, in this embodiment in the stateThe non-edge core, edge core, and bridge core are made into one core (one upper core 1310 and one lower core 1410). By doing so, an induction heating device having the effects described in the first and second embodiments is realized. Also, the spin-spin coupling between the spins of the constituent atoms in the region corresponding to the bridge cores 620a and 620b and the spins of the constituent atoms in the region corresponding to the non-edge core 611 and the edge cores 612 and 613 can be further increased. Thereby, the magnetic flux density generated in these regions by passing an alternating current through the coil 220 can be made higher than in the case where the non-edge core 611 and the edge cores 612 and 613 and the bridge cores 620a and 620b are separate cores.

[0195] And, similar to the second embodiment, in this embodiment as well, the temperature rise of the upper core 1310 can be suppressed by the cooling fins 630a to 630h and the cooling small tubes 640a to 640h. The same applies to the lower inductor 1400.

[0196] As described above, also in this embodiment as in the second embodiment, it is possible to provide an induction heating device capable of simultaneously suppressing the temperature of the core below a desired temperature and generating an alternating magnetic field of a desired magnitude.

[0197] Note that, as is clear from the above description, the configuration of this embodiment is such that the edge core, non-edge core, bridge core, partial edge core, and partial non-edge core described in the second embodiment are replaced with the regions corresponding to the edge core, the region corresponding to the non-edge core, the region corresponding to the bridge core, the region corresponding to the partial edge core, and the region corresponding to the partial non-edge core, respectively. Therefore, by making such a replacement and re-reading the description of the second embodiment, the following preferred ranges are defined.

[0198] · The preferred range of the plate center side lap length L of the region corresponding to the bridge cores 620a and 620b (L ≧ α, etc.) · Preferred range of the plate end side lap length L’ of the region corresponding to the bridge cores 620a and 620b (L’≧α, etc.) · Preferred range of the height H of the region corresponding to the bridge cores 620a and 620b (H≧Min(0.5×h, 0.5×α), etc.) · Region corresponding to the partial non-edge cores 611a to 611c and partial edge cores 612a to 6 12c, 613a to 613c, preferred range of the ratio of the length BL in the y-axis direction of the region corresponding to the bridge cores 620a and 620b to the length CL in the y-axis direction of the region (BL / CL≧0.2, etc.)

[0199] <Modification example> In this embodiment, the case where the region 1312 of the upper core 1310 has a rectangular parallelepiped shape is illustrated. However, the shape of the region 1312 of the upper core 1310 is not limited to the rectangular parallelepiped shape. For example, as shown in FIG. 26, one or more recessed portions may be formed on the end surface (lower surface) on the conveyance planned surface CP side of the region 1312 of the upper core 1310 (note that FIG. 26 is a cross-sectional view corresponding to FIG. 19). FIG. 26 illustrates the case where two recessed portions are formed in the region 1312 of the upper core 1310 at intervals in the x-axis direction. Further, as shown in FIG. 26, cooling fins 630i to 630j and cooling small tubes 640i to 640j similar to the cooling fins 630a to 630h and cooling small tubes 640a to 640h may be arranged in the recessed portions. In FIG. 26, the case where the height (length in the z-axis direction) of the cooling fins 630i to 630j is lower than that of the cooling fins 630a to 630d and 630e to 630h so that the cooling small tubes 640i to 640j do not reach the end surface (upper surface) on the back side of the region 1312 is illustrated. In this way, both the arrangement of the cooling fins 630 i ~630 j and the cooling small tubes 640 i ~640 j in the region 1312 of the upper core 1310 and the fact that the regions 1311a, 1311b, and 1312 are an integrated single core are realized.

[0200] Also, as shown in FIG. 26, for the lower core 1410 as well, cooling fins 730i to 730j and cooling small tubes 740i to 740j similar to the cooling fins 730a to 730h and the cooling small tubes 740a to 740h may be arranged. In FIG. 26, a case is exemplified where the height (length in the z-axis direction) of the cooling fins 730i to 730j is lower than the height of the cooling fins 730a to 730d and 730e to 730h, similar to the cooling fins 630i to 630j.

[0201] In addition, the y-z cross section at the position where the cooling fins 630i to 630j, 730i to 730j and the cooling small tubes 640i to 640j, 740i to 740j are arranged is a cross section in which the length in the z-axis direction of the cooling fins 630d, 730d, the upper core 1310, and the lower core 1410 in FIG. 23 is changed to the length in the z-axis direction of the cooling fins 630i to 630j, 730i to 730j and the upper core 1310, the lower core 1410 at the position where the cooling fins 630i to 630j, 730i to 730j and the cooling small tubes 640i to 640j, 740i to 740j are arranged, respectively.

[0202] Also, in this embodiment, a case where the height (length in the z-axis direction) of the region 1312 of the upper core 1310 is lower than the height of the other regions of the upper core 1310 is exemplified. However, it is not necessarily required to be like this. For example, the height (length in the z-axis direction) of the region 1312 of the upper core 1310 may be the same regardless of the position in the x-axis direction. FIG. 27 exemplifies a case where a region corresponding to a bridge core is included in the entire region 1311c in the x-axis direction of the upper core 1310 (note that FIG. 27 is a cross-sectional view corresponding to FIG. 19). The above-described modifications may be adopted for the lower inductor 1400.

[0203] In addition, various modifications described in the first embodiment and the second embodiment may be adopted for the induction heating device of this embodiment. Also, a modification combining at least two of the above-described modifications including the modifications described in the first embodiment and the second embodiment may be adopted for the induction heating device of this embodiment.

[0204] (Fourth Embodiment) Next, a fourth embodiment of the present invention will be described. In the second embodiment, the case where non-magnetic conductors configured to be coolable are arranged between the partial non-edge cores 611a to 611c, between the partial edge cores 612a to 612c and 613a to 613c, and between the partial edge cores 612c, 613c and the partial non-edge cores 611a, 611c was exemplified. In this embodiment, in addition to this, the case where non-magnetic conductors configured to be coolable are arranged on the end faces (upper surface, lower surface) on the back side of the bridge cores 620a to 620b and 720a to 720b will be exemplified. By doing so, the temperature of the bridge cores 620a to 620b and 720a to 720b can be further reduced. Thus, in this embodiment, a configuration for reducing the temperature of the bridge cores 620a to 620b and 720a to 720b is added to the induction heating device of the second embodiment. Therefore, in the description of this embodiment, for the same parts as those in the first embodiment, the second embodiment, and the third embodiment, the same reference numerals as those attached to FIGS. 1 to 27 will be used and detailed description will be omitted.

[0205] FIG. 28 is a diagram showing an example of a first cross-section of the induction heating device and corresponds to FIG. 8. FIG. 29 is a diagram showing an example of a second cross-section of the induction heating device and corresponds to FIG. 10. Also in this embodiment, similar to the second embodiment, the case where the induction heating device has a shape with a mirror-symmetrical relationship with the y-z plane at the center in the x-axis direction of the induction heating device as the symmetry plane will be exemplified.

[0206] In FIGS. 28 and 29, the case where the cooling pipes 2210a and 2210b are arranged on the end faces (upper surface) on the back side of the bridge cores 620a and 620b of the upper inductor 2200 is exemplified. Similarly, in FIGS. 28 and 29, the case where the cooling pipes 2310a and 2310b are arranged on the end faces (lower surface) on the back side of the bridge cores 720a and 720b of the lower inductor 2300 is exemplified. Also in this embodiment, the case where the outer shapes of the cooling pipes 2210a, 2210b, 2310a, and 2310b are in a zigzag shape is exemplified.

[0207] The cooling pipes 2210a and 2210b are arranged in a zigzag pattern on the end faces (upper surfaces) on the back side of the bridge cores 620a and 620b. Further, the cooling pipes 2210a and 2210b are in contact with the bridge cores 620a and 620b. The cooling pipes 2210a and 2210b are made of, for example, a non-magnetic conductor such as copper. Similarly, the cooling pipes 2310a and 2310b are arranged in a zigzag pattern on the end faces (lower surfaces) on the back side of the bridge cores 720a and 720b. The cooling pipes 2310a and 2310b are in contact with the bridge cores 720a and 720b. The cooling pipes 2310a and 2310b are also made of, for example, a non-magnetic conductor such as copper.

[0208] In the configuration of the second embodiment, for example, the temperature rise of the bridge cores 620a and 620b can be suppressed by the small cooling pipes 640a to 640h and air cooling. However, in such a configuration, for example, when the temperature around the induction heating device is high, there is a possibility that the temperature of the bridge cores 620a and 620b cannot be lowered to a desired temperature. On the other hand, in the present embodiment, the cooling pipes 2210a and 2210b are arranged on the end faces (upper surfaces) on the back side of the bridge cores 620a and 620b. Therefore, the temperature of the bridge cores 620a and 620b can be lowered more than in the configuration of the second embodiment. Thus, in the present embodiment, in addition to the effects described in the second embodiment, there is an effect that the temperature of the bridge cores 620a and 620b can be surely lowered. The above also applies to the lower inductor 2300.

[0209] <Modification> In the present embodiment, the case where the cooling pipes 2210a and 2210b are used as an example of the cooling member for cooling the bridge cores 620a and 620b is illustrated. However, the cooling member for cooling the bridge cores 620a and 620b is not limited to such a cooling member. For example, the cooling member for cooling the bridge cores 620a and 620b may be a plate-shaped non-magnetic conductor. In this case, the plate-shaped non-magnetic conductor may be cooled by heat conduction.

[0210] In addition, in the present embodiment, the case where the cooling pipes 2210a and 2210b are added to the induction heating device of the second embodiment is illustrated. However, the cooling pipes 2210a and 2210b may be added to the induction heating device of the third embodiment. The above modifications may be adopted for the lower inductor 2300. In addition, various modifications described in the first embodiment, the second embodiment, and the third embodiment may be adopted for the induction heating device of the present embodiment. Further, a modification combining at least two of the above modifications including the modifications described in the first embodiment, the second embodiment, and the third embodiment may be adopted for the induction heating device of the present embodiment.

[0211] In addition, as in the second embodiment and the fourth embodiment, when the upper core 610 and the lower core 710, and the bridge cores 620a to 620b, 720a to 720b are separate cores, the bridge cores 620a, 620b, 720a, 720b may be moved in the x-axis direction in accordance with the movement of the shielding plates 230a, 230b, 330a, 330b in the x-axis direction. The movement of the shielding plates 230a, 230b, 330a, 330b in the x-axis direction is executed as described in the second embodiment. For example, when the strip steel plate 100 meanders, when moving the shielding plates 230a, 230b, 330a, 330b in the x-axis direction (the direction in which the strip steel plate 100 meanders), the bridge cores 620a, 620b, 720a, 720b and the shielding plates 230a, 230b, 330a, 330b may be moved in the x-axis direction (the direction in which the strip steel plate 100 meanders) by the same amount as the amount of meandering of the strip steel plate 100.

[0212] It should be noted that the embodiments of the present invention described above are merely examples of the implementation of the present invention, and the technical scope of the present invention should not be construed in a limited manner by these. That is, the present invention can be implemented in various forms without departing from its technical idea or its main features.

Industrial Applicability

[0213] The present invention can be used, for example, to inductively heat a conductor plate.

Claims

1. A pair of coils, each of which is disposed on at least one of the front side and the back side of the planned conveyance surface of the conductor plate such that an alternating magnetic field generated by passing an alternating current in the same direction intersects the planned conveyance surface of the conductor plate; A transformerless induction heating device comprising cores arranged in sets for each one of the pair of coils, wherein The set of cores arranged for each one of the coils includes a non-edge core disposed at a position including the center in the width direction and edge cores disposed on both sides of the non-edge core in the width direction, The width direction is a direction perpendicular to the conveyance direction of the conductor plate and the facing direction of the coils, The non-edge core has a body portion and a central leg portion, Each of the edge cores disposed on both sides of the non-edge core in the width direction has a body portion, a central leg portion, an upstream leg portion, and a downstream leg portion, The body portion extends in the conveyance direction from a region upstream of the coil in the conveyance direction to a region downstream of the coil in the conveyance direction on the back side of the coil, The back side is the side opposite to the side where the planned conveyance surface exists, The central leg portion extends from the body portion in the direction of the planned conveyance surface so as to pass through the hollow portion of the coil, The upstream leg portion extends from the body portion in the direction of the planned conveyance surface upstream of the coil, The downstream leg portion extends from the body portion in the direction of the planned conveyance surface downstream of the coil, The intervals between the upstream leg portion and the downstream leg portion of the edge core and the planned conveyance surface are shorter than the intervals between the portions of the non-edge core other than the central leg portion and the planned conveyance surface, The interval between the central leg portion of the non-edge core and the planned conveyance surface is shorter than the intervals between the portions of the non-edge core other than the central leg portion and the planned conveyance surface, The transverse induction heating device, wherein a part of the coil is located outside the edge core in the width direction.

2. The transverse induction heating device according to claim 1, wherein the non-edge core does not have the upstream leg portion and the downstream leg portion.

3. The transverse induction heating device according to claim 1 or 2, wherein the non-edge core has the upstream leg portion and the downstream leg portion.

4. The transverse induction heating device according to claim 1 or 2, wherein the distance between the central leg portion of the edge core and the planned conveying surface is the same as the distance between the upstream leg portion and the downstream leg portion of the edge core and the planned conveying surface.

5. The transverse induction heating device according to claim 1 or 2, wherein the distance between the central leg portion of the edge core and the planned conveying surface is the same as the distance between the central leg portion of the non-edge core and the planned conveying surface.

6. The transverse induction heating device according to claim 1 or 2, wherein in the set of cores, the non-edge core and the two edge cores arranged on both sides of the non-edge core are integral cores.

Images