JP3707724B2 - Induction heating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an induction heating apparatus that is disposed in the middle of a conveying line such as a hot rolling line for steel and continuously heats a member to be heated.
[0002]
[Prior art]
FIG. 9 is a side sectional view showing the structure of this kind of conventional induction heating apparatus disclosed in, for example, Japanese Patent Laid-Open No. 10-134949, FIG. 10 is a front view showing the induction heating apparatus in FIG. 9, and FIG. FIG. 12 is a perspective view showing a magnetic flux distribution state at the end portion of the iron core in FIG. 9.
[0003]
In the figure, reference numeral 1 denotes, for example, a steel strip as a member to be heated which is roughly rolled by a preceding roughing mill and conveyed by a table roller 2 in a hot rolling line for steel, and 3 circulates in the width direction of the steel strip 1. The solenoid coil is formed by winding a copper tube in an oval shape, and a high-frequency current is supplied from a power supply device (not shown) via the coil terminal portion 4. 5 is a coil support frame that supports the solenoid coil 3, 6 is a heat-resistant member that is disposed inside the solenoid coil 3 and forms the passage 7 of the steel strip 1, and 8 is along a magnetic path outside the solenoid coil 3, A plurality of U-shaped iron cores 9 arranged side by side in the width direction of the steel strip 1 are shield copper plate members 9 for preventing the magnetic flux 10 of the solenoid coil 3 from leaking to the outside.
[0004]
In general, the steel strip 1 as a plate-like member to be heated that has been roughly rolled is radiated while being transported by the table roller 2 and sent to the next process, and the temperature is lowered. And the induction heating apparatus comprised as mentioned above is arrange | positioned in the middle, and the steel strip 1 is induction-heated by passing the inside of the channel | path 7 formed inside the solenoid coil 3, and the temperature fall during conveyance is carried out. It is made to compensate.
[0005]
Further, when a high-frequency current flows through the solenoid coil 3, an alternating magnetic flux 10 is generated along the conveying direction of the steel strip 1 and the steel strip 1 is heated. At this time, if this magnetic flux 10 leaks to the outside, this leakage Since the table roller 2 is heated by the magnetic flux and sparks may occur at the contact position between the steel strip 1 and the table roller 2, the iron core 8 and the shield copper plate member 9 shield the magnetic flux 10 from leaking to the outside. It is prevented from occurring.
Furthermore, as apparent from the figure, the iron core 8 has a U-shape because the flow of the magnetic flux 10 is changed as shown in FIG. 11 to chain the copper tube forming the solenoid coil 3. The purpose is to reduce the induction flux of the copper tube itself and to prevent overheating in order to reduce the magnetic flux.
[0006]
[Problems to be solved by the invention]
As described above, the conventional induction heating apparatus is provided with the iron core 8 and the shield copper plate member 9, thereby preventing the magnetic flux 10 from leaking to the outside and preventing the occurrence of sparks. By doing so, the interlinkage magnetic flux to the copper pipe which forms the iron core 8 is reduced, and the overheating of the copper pipe itself is prevented.
However, since a plurality of iron cores 8 are arranged side by side in the width direction of the steel strip 1, the magnetic flux 10 is concentrated at the position of the iron core 8 as shown in FIG. The portion of the magnetic flux 10 interlinking with the tube that corresponds to the iron core 8 is greater than the portion that does not have the iron core 8, and local heat generation is greater at this portion. Therefore, it is impossible to sufficiently reduce the overheating of the copper tube even if the iron core 8 and U-shaped.
[0007]
This problem becomes more pronounced as the arrangement ratio of the iron core 8 with respect to the circumference of the solenoid coil 3 becomes smaller. Since it is also substantially difficult to do so, local heat generation at a portion corresponding to the iron core 8 of the copper tube cannot be reduced, and in some cases, water leakage occurs due to deterioration of the copper tube . Then, because such forced to limit the current supplied to the solenoid coil 3, can not be increased significantly to heating power density electric current, it is possible to increase the heating capacity of the induction heating device per vehicle There is also a problem that it cannot be done .
[0008]
The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide an induction heating apparatus having a large heating capacity by reducing local heat generation of a copper pipe forming a solenoid coil. is there.
[0009]
[Means for Solving the Problems]
In the induction heating apparatus according to the first aspect of the present invention, a plurality of iron cores are arranged in parallel along the magnetic path outside the solenoid coil for inductively heating the member to be heated conveyed through the line to the inside. In induction heating equipment,
A first copper plate member formed in a frame shape along the winding region of the solenoid coil and disposed on the outermost side in the vicinity of both ends of each iron core, at least one cut on the circumference along the winding region of the solenoid coil The first copper plate member formed in the shape of a frame having a portion, the second copper plate member disposed via a predetermined gap, and the magnetic plate member are laminated and formed in the gap between the copper plate members. The laminated core member is provided.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Embodiments of the present invention will be described below with reference to the drawings. 1 is a side sectional view showing the configuration of the induction heating apparatus according to Embodiment 1 of the present invention, FIG. 2 is a front view showing the induction heating apparatus in FIG. 1, and FIG. 3 is the configuration of the first copper plate member shown in FIG. 4 is a perspective view showing the configuration of the second copper plate member shown in FIG. 1, FIG. 5 is a perspective view showing the configuration of the second copper plate member different from FIG. 4, and FIG. 7 is a perspective view showing the configuration of the laminated core member shown in FIG. 7, FIG. 7 is a cross-sectional view showing the distribution state of magnetic flux in the vicinity of the end of the iron core of the induction heating device shown in FIG. 1, and FIG. It is a figure which shows the surface local maximum temperature rise value of each part of a copper pipe compared with the conventional apparatus.
[0011]
In the figure, reference numeral 11 denotes a steel strip as a member to be heated which is roughly rolled by a preceding roughing mill in a hot rolling line for steel and is conveyed by a table roller 12, and 13 circulates in the width direction of the steel strip 11. The solenoid coil is formed by winding a copper tube in an oval shape so that a high-frequency current is supplied from the power supply device 15 via the coil terminal portion 14. Reference numeral 16 denotes a coil support frame that supports the solenoid coil 13, and 17 denotes a heat-resistant member that is disposed inside the solenoid coil 13 and forms the passage 18 of the steel strip 11. And the structure until now is substantially the same as the conventional induction heating apparatus.
[0012]
19 is a rectangular parallelepiped core arranged in parallel in the width direction of the steel strip 11 along the magnetic path outside the solenoid coil 3, and 20 is a notch 21a on one side as shown in FIG. A pair of copper plates 21 each formed with a bent edge portion 21b bent at 90 ° at both ends of the notch 21a are combined so that the notches 21a coincide with each other to form a window portion 21c. For example, the first copper plate member integrated into a frame shape by fastening the bolts 21b with bolts 22, for example, is disposed at both ends of the heat-resistant member 17 so that the window portions 21c coincide with the passages 18, and the outer edge portion. The both ends of each iron core 19 are supported.
[0013]
As shown in FIG. 4, a window portion 24a is formed in the center of the copper plate 24 to form a frame, and a second copper plate member having a cut portion 24b formed in at least one place on the periphery thereof. 24a is fitted to the outer periphery of the heat-resistant member 17, and is disposed inside the first copper plate member 20 with a predetermined gap. For example, as shown in FIG. 6, a laminated iron core 25 is formed in a frame shape by forming a window portion 25a by combining a plurality of iron core blocks 26 formed by laminating magnetic plate members such as silicon steel plates. As a member, the window portion 25 a is fitted to the outer periphery of the heat-resistant member 17 and is mounted in the gap between the first and second copper plate members 20 and 23.
[0014]
Also in the induction heating device according to the first embodiment configured as described above, when a high-frequency current flows from the power supply device 15 to the solenoid coil 13 as in the conventional device, the alternating magnetic flux 27 along the conveying direction of the steel strip 11. Is generated and the steel strip 11 is heated. At this time, the flow of the alternating magnetic flux 27 at the device end is in a state as shown in FIG. That is, since the first copper plate member 20 is formed in a frame shape and electrically forms one loop with respect to the passage 18 through which the steel strip 11 is conveyed, the shield that prevents the magnetic flux 27 from leaking to the outside. second copper plate member 23 while has the effect cutting portion 24b is formed in a frame-like peripheral on, because it does not form an electrically one loop, prevent the magnetic flux 27 from leaking to the outside However, since the magnetic flux 27 can be prevented from penetrating through the second copper plate member 23 itself, most of the magnetic flux 27 flows through the laminated iron core member 25 and reaches the iron core 19. A magnetic path is formed, and the magnetic flux 27 is prevented from interlinking with the copper tube at the end as is apparent from the figure. Further, since the laminated core member 25 is arranged over the entire circumference of the winding region of the solenoid coil 13 without being blocked by the coil terminal portion 14 or the coil support frame 16, the magnetic flux 27 is concentrated only on the portion corresponding to the core 19. It becomes equal without doing, and fever does not increase or decrease locally.
[0015]
FIG. 8 shows each part of the copper tube arranged at the end of the solenoid coil in the induction heating device according to the first embodiment configured as described above and the conventional induction heating device described in FIGS. It is a figure which shows the experimental result which compared the maximum temperature rising value.
First, a rectangular copper tube having a width of 25 mm × a height of 25 mm and a thickness of 3 mm is formed on the solenoid coils 3 and 13 formed so that the winding dimensions are a width of 2000 mm × a height of 210 mm. The laminated iron core member 25 of 50 mm and the rod-shaped iron core 19 having a width of 200 mm are arranged at a distance of 300 mm in the width direction of the steel strip 11, and six pieces are arranged at the bottom. Has a structure in which six U-shaped iron cores 8 of 200 mm are arranged at intervals of 300 mm in the width direction of the steel strip, respectively, and the flow rate of cooling water flowing through the copper pipe is 2.2 m / In comparison, the power input to the solenoid coils 3 and 13 is 5000 KW. In the figure, the horizontal axis indicates the temperature measurement part on the surface of the endmost copper tube, and the vertical axis indicates the maximum temperature rise value at each part. In The
[0016]
As is clear from the figure, the maximum temperature rise value in each portion of the surface of the endmost copper tube in the first embodiment indicated by the solid line is substantially uniform, whereas the maximum temperature rise value in the conventional example indicated by the broken line is The portion corresponding to the iron core 8 is higher than the other portions, particularly the highest temperature rise value at the end portion in the width direction, which is about 30% higher than the temperature rise value in the first embodiment. The value is high.
[0017]
Thus, according to the first embodiment, the first copper plate member 20 formed in a frame shape along the winding region of the solenoid coil 13 and the circumference along the winding region of the solenoid coil 13, A laminated copper core member 25 formed by laminating a second copper plate member 23 formed in a frame shape having at least one cut portion 24b and a magnetic plate member and disposed between the copper plate members 20 and 23. By arranging the magnetic flux 27 on the device end side, most of the magnetic flux 27 passes through the laminated iron core member 25 and flows to the iron core 19, so that local heat generation of the copper pipe forming the solenoid coil 13 is reduced and the copper pipe It is possible to suppress deterioration and increase the heating capacity.
[0018]
In the above configuration, the first copper plate member 20 is formed by combining a pair of copper plates 21, but it is not necessarily required to have a divided structure, and may be formed of a single copper plate, Further, the second copper plate member 23 is formed by processing the window portion 24a and the cutting portion 24b on one copper plate 24, but the two pieces formed in a U-shape as shown in FIG. By combining the copper plate 28, the window portion 29a and the cut portion 29b may be formed as the second copper plate 29, and the same effects as in the first embodiment can be obtained.
[0019]
【The invention's effect】
As described above, according to the first aspect of the present invention, the plurality of iron cores are arranged in parallel along the magnetic path outside the solenoid coil that performs induction heating by passing the heated member conveyed on the inside to the inside. Inductive heating apparatus
A first copper plate member formed in a frame shape along the winding region of the solenoid coil and disposed on the outermost side in the vicinity of both ends of each iron core, at least one cut on the circumference along the winding region of the solenoid coil The first copper plate member formed in the shape of a frame having a portion, the second copper plate member disposed via a predetermined gap, and the magnetic plate member are laminated and formed in the gap between the copper plate members. Since the laminated core member is provided, it is possible to provide an induction heating device having a large heating capacity by reducing local heat generation of the copper pipe forming the solenoid coil to suppress deterioration.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a configuration of an induction heating device according to Embodiment 1 of the present invention.
FIG. 2 is a front view showing the induction heating device in FIG.
FIG. 3 is a perspective view showing a configuration of a first copper plate member shown in FIG. 1;
4 is a perspective view showing a configuration of a second copper plate member shown in FIG. 1. FIG.
FIG. 5 is a perspective view showing a configuration of a second copper plate member different from that in FIG. 4;
6 is a perspective view showing the configuration of the laminated core member shown in FIG. 1. FIG.
7 is a cross-sectional view showing a magnetic flux distribution state in the vicinity of the end of the iron core of the induction heating apparatus shown in FIG.
FIG. 8 is a diagram showing the surface maximum local temperature rise value of each part of the endmost copper tube of the induction heating device in FIG. 1 in comparison with that in the conventional device.
FIG. 9 is a side sectional view showing a configuration of a conventional induction heating apparatus.
10 is a front view showing the induction heating device in FIG. 9. FIG.
11 is a side view showing a distribution state of magnetic flux at the end of the iron core in FIG. 9. FIG.
12 is a perspective view showing a distribution state of magnetic flux at the end of the iron core in FIG. 9. FIG.
[Explanation of symbols]
11 steel strip, 13 solenoid coil, 17 heat-resistant member, 18 passage,
19 iron core, 20 first copper plate member, 21, 24, 28 copper plate,
21c, 24a, 25a, 29a window part, 24b, 29b cutting part,
23, 29 Second copper plate member, 25 laminated core member, 27 magnetic flux.

Claims (1)

In an induction heating apparatus in which a plurality of iron cores are arranged in parallel along a magnetic path outside a solenoid coil that performs induction heating by passing a heated member conveyed through the line,
A first copper plate member formed in a frame shape along the winding region of the solenoid coil and disposed on the outermost side in the vicinity of both ends of each iron core, at least on the circumference along the winding region of the solenoid coil The two copper plate members formed by laminating the first copper plate member and the second copper plate member disposed via a predetermined gap, and a magnetic plate member formed in a frame shape having a cut portion at one place. An induction heating apparatus comprising a laminated core member disposed in a gap therebetween.

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