JPH11251048A - Induction heating device and induction heating method for strip metal material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably heat a magnetic material without drawing it to inductors by providing rolls kept in contact with a strip metal material and regulating its pass line on one of the inlet side and outlet side of the inductors, and providing rolls kept in winding contact with the strip metal material on the other side so that at least one of the rolls can be freely moved. SOLUTION: When a traveling magnetic strip metal material 1 approaches one of inductors 2, 3, there is a danger that the strip metal material 1 is brought into contact with the inductor to damage it by the effect of the magnetic force of the inductor. Rolls 4, 5, 7, 8 are provided in the front and rear of the inductors 2, 3 so that the strip metal material 1 passes between the inductors 2, 3. The traveling strip metal material 1 inevitably passes between the inductors 2, 3, and it can be stably heated even if it has magnetism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating apparatus for heating a traveling strip-shaped metal material such as iron, aluminum, and copper, and maintains a positional relationship between an induction heating inductor and the strip-shaped metal material within a certain range. Prevents poor heating temperature distribution resulting from poor positional relationship between the induction heating inductor and the band-shaped metal material and the resulting heating shape defect, and also prevents poor sheet passing due to being drawn to the induction heating inductor. The present invention relates to an induction heating apparatus and an induction heating method capable of stably induction heating a material to be heated.

[0002]

2. Description of the Related Art Hitherto, when heating a running strip-shaped metal material, the heating and keeping the heat mostly involve radiation by gas heating or indirect heating by an electric heater. However, these heating methods indirectly heat the material to be heated from the surface, so that there is a problem that rapid heating cannot be performed, which greatly restricts productivity.

[0003] In order to solve this problem, a method of heating using electricity has been proposed. For example, JP-A-2-3015
No. 22 discloses a method of heating a steel sheet through a solenoid coil. This method is effective when the material to be heated is a magnetic substance and is heated below the Curie point, but it is difficult to heat above a non-magnetic material or above the Curie point, the heating efficiency is low, and the plate thickness is low. There is a problem that the power supply frequency needs to be increased for thin ones, and the power supply cost increases.

On the other hand, for example, US Pat.
03994 describes a method of heating a magnetic flux generated by an inductor through a material to be heated. Such heating is generally performed by a transverse flux (hereinafter TF).
It is said that heating can be performed with high efficiency regardless of the magnetic or non-magnetic properties of the material to be heated and without being affected by the thickness.

Although TF heating is an excellent heating method, it has several problems. First, when heating a magnetic material, there is a problem that an inductor that generates a magnetic flux becomes an electromagnet, and a material to be heated is attracted to the inductor. When the material to be heated is attracted to the inductor and comes into contact with the inductor, a short circuit occurs and damages the inductor.In addition, the magnetic flux is overheated and the temperature distribution becomes non-uniform. As a result, there arises a problem that the sheet passing property is significantly deteriorated.

Second, the TF heating has a problem that the edge is likely to be overheated because the density of the eddy current generated in the material to be heated increases at the edge. For this problem,
In the above-mentioned US Pat. No. 5,003,994, the solution is achieved by a method of reducing the current density at the edge portion or a method of masking the edge portion to reduce the magnetic flux, by making the shape of the inductor J-shaped. However, the traveling strip-shaped metal material actually tends to meander, etc., and cannot always stay at an appropriate position between the inductor and the inductor. Therefore, the heating temperature distribution greatly changes immediately as soon as it deviates from the appropriate position. There is a problem.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention provides an induction heating apparatus and an induction heating method which can solve the above-mentioned problems that occur when a running strip-shaped metal material is induction-heated.

[0008]

The gist of the present invention for solving the above problems is as follows. (1) In an apparatus for heating a traveling strip-shaped metal material by induction heating inductors arranged on both sides of the traveling surface of the traveling strip-shaped metal material, either the entrance side or the exit side of the inductor is heated. On one side, a roll that contacts the strip-shaped metal material and regulates the pass line of the strip-shaped metal material is provided, and at the other end, a freely movable roll that contacts at least one end side so that the strip-shaped metal material is wound around is provided. An induction heating apparatus for a strip-shaped metal material.

(2) The heating device according to the above (1), wherein a position detecting device for detecting a position in a width direction of the band-shaped metal material is provided upstream or downstream of the induction heating inductor. Material induction heating device.

(3) Using the induction heating device described in (2) above, moving the roll around which the band-shaped metal material is wound, based on the position information of the band-shaped metal material detected by the position detection device for the band-shaped metal material, An induction heating method for a strip-shaped metal material, wherein the induction heating is performed by always controlling the positional relationship in the width direction between the strip-shaped metal material and the induction heating inductor within a certain range.

(4) In an apparatus for heating a running strip-shaped metal material by induction heating inductors disposed on both sides of the running face of the running strip-shaped metal material, an inlet and an outlet of the induction-heating inductor are connected. Induction heating of a strip-shaped metal material characterized in that a fixed gap is opened so that a pair of rolls face each other so that a running strip-shaped metal material passes through the center of the opposed inductor on at least one of the sides. apparatus.

(5) In an apparatus for heating a running strip-shaped metal material by induction heating inductors disposed on both sides of the running face of the running strip-shaped metal material, an inlet and an outlet of the induction-heating inductor are provided. A belt-shaped metal material in which the rolls are arranged at regular intervals in the longitudinal direction of the metal-band material so that the running metal-band material passes through the center of the opposed inductor on at least one of the sides. Induction heating device for metal materials.

(6) The above (1), (2), (3),
(4) The induction heating device for a strip-shaped metal material, wherein the roll surface according to any one of (5) and (5) is made of a non-conductive material.

(7) The above (1), (2), (3),
(4) An apparatus for induction heating a strip-shaped metal material, wherein the roll according to any one of (5) and (5) is made of a non-magnetic material.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2, a running strip-shaped metal material 1 includes an inductor 2 and an inductor 3 connected to a high-frequency power source 6 including a matching board (not shown).
When passing through the magnetic field generated by the above, an eddy current is induced in the strip-shaped metal material 1 by the magnetic flux penetrating the surface and is heated.

At this time, if the running strip-shaped metal material 1 passes between the inductor 2 and the inductor 3, the magnetic force generated from both inductors is canceled out and no problem occurs, but the strip-shaped metal material 1 has magnetism. When approaching either of the inductors, the strip-shaped metal material 1 is attracted to the inductor by the influence of the magnetic force of the inductor.

When the attracted magnetic force is strong, the running strip-shaped metal material 1 comes into contact with the inductor and is short-circuited with the inductor, so that there is a high risk of damaging the inductor. Also, if the inductor is too close to the inductor, it is subjected to local heating and a temperature distribution occurs. As a result, the running metal strip 1 is deformed by thermal stress, or the running metal strip 1 comes into contact with the inductor, and the surface of the metal strip 1 contacts the inductor. May be scratched.

Therefore, in the present invention, by providing rolls 4, 5, 7, and 8 before and after the inductors 2 and 3, the traveling strip-shaped metal material 1 is formed by the inductor 2 and the inductor 3.
Pass through the middle of In this case, the traveling strip-shaped metal material 1 is restricted by the roll 4 or the roll 5, and does not pass through a pass line inside. Since the pass line of the traveling strip-shaped metal material 1 is also restricted by the roll 7 near the upstream of the roll 4 and the roll 8 near the downstream of the roll 5, the traveling strip-shaped metal material 1 is restricted.
Is forced to pass between the inductor 2 and the inductor 3, so that stable heating can be performed even if the running strip-shaped metal material 1 has magnetism.

Alternatively, as a method of similarly defining a pass line, the rolls 4 and 7 may be arranged with a gap in the strip-shaped metal material 1 running as shown in FIG. Since the running strip-shaped metal material 1 cannot approach the inductor 2 or the inductor 3 beyond the gap regulated by the rolls 4 and 7, even if the running strip-shaped metal material 1 has magnetism, it is stable. Heating.

Similarly, an example is shown in which the rolls 5 and 8 are arranged in the longitudinal direction with a slight gap from the path of the running strip-shaped metal material 1. Also by this method, the pass line of the running strip-shaped metal material 1 can be kept within a certain range. There is no particular limitation on the gap between the rolls, but a sufficient gap may be provided so as not to apply a rolling force from the roll within a range where the influence of the magnetic force of the inductor does not matter.

In FIG. 2, a gap is provided before and after the inductor. However, when the running strip-shaped metal material 1 enters the inductor at room temperature, the rolls 4 and 7 pinch the running strip-shaped metal material 1 without opening a gap. However, it is preferable to provide a small gap between the roll 5 and the roll 8.
The reason is that, when the running strip-shaped metal material 1 is pinched while being heated, a squeeze is likely to occur when the pinch is heated, and due to uneven cooling by a roll, thermal stress is generated in the strip-shaped metal material 1 and the shape is easily deteriorated. In particular, when the plate thickness is small, the squeezing easily occurs. Further, since the heated strip-shaped metal material 1 is cooled, the efficiency is reduced.

The rolls 4, 5, 7, and 8 are rotated in synchronization with the speed of the running strip-shaped metal material 1 because the rolls 4, 5, 7, and 8 may cause abrasion when the running strip-shaped metal material 1 comes into contact. It is desirable to keep.

FIG. 3 shows an example in which the rolls are spaced apart from each other in the longitudinal direction so as to face each other. Even in this manner, the pass line of the traveling strip-shaped metal material 1 can be maintained. In the case of TF heating, a more important factor in the positional relationship between the running strip-shaped metal material 1 and the inductor is the positional relationship between the inductor and the running strip-shaped metal material 1 in the width direction. In particular, since the current density at the edge of the strip-shaped metal material 1 most affects the heating temperature deviation, it is necessary to keep the positional relationship between the edge and the inductor optimal. For that purpose, it is necessary to control so that the edge of the running strip-shaped metal material 1 passes through a specific position of the inductor.

FIG. 1 shows an induction heating apparatus according to the present invention.
The running strip-shaped metal material 1 is arranged so as to be pushed from the pass line by the roll 7 and wound around the roll 4. Before the traveling strip-shaped metal material 1 that has passed through the roll 4 enters the inductors 2 and 3, the position in the width direction of the inductors 2 and 3 is detected by the steel plate position detection devices 9 and 10. The strip-shaped metal material 1 that travels when the roll 4 moves according to position signals from the position detecting devices 9 and 10.
Can always pass through the optimal position with the inductor.

FIG. 4 is a front view as viewed from the right in FIG. A thick line schematically shown in the drawing is an appropriate position through which the edge of the running strip-shaped metal material 1 passes. The traveling strip-shaped metal material 1 that has entered the inductor is heated and goes to the outlet, expands and passes through a position like a thick line.

On the other hand, the line shown by the thin line schematically shows the position where the edge of the running strip-shaped metal material 1 meanders to the left. In this case, wrinkles are easily generated between the rolls 4 and 5 in the running strip-shaped metal material 1. In the case of this example, wrinkles are going to be generated from the right side of the roll 4 to the left side of the roll 5. In order to prevent the meandering, the roll 4 may be moved so as to eliminate the wrinkle. In this example, the right side of the roll 4 moves toward the roll 5 or the left side of the roll 4 faces the roll 7. I just need to move.

As the position detecting devices 9 and 10 for detecting the position of the running strip-shaped metal material 1, a method for detecting the position by transmitting light, an image sensor such as a CCD, or the like may be used. Further, as a method of driving the roll 4, the roll 4 may be moved back and forth in the traveling direction of the strip-shaped metal material 1, or up and down or obliquely when the influence of the magnetic force is small. As a mechanism for moving the roll, a method of moving the roll together with the roll chock using a hydraulic pressure, an electric cylinder, or the like may be used.

In the case of performing induction heating, the rolls 4, 5, 7, and 8 described above are arranged near the inductors 2 and 3, so that the magnetic flux leaking from the inductors 2 and 3 causes the traveling strip-shaped metal material to run. 1 and rolls 4, 5, 7,
In some cases, a current is induced in 8 itself. For this reason, a spark may be generated between the running strip-shaped metal material 1 and the rolls 4, 5, 7, and 8, and there is a concern that the spark may damage the running strip-shaped metal material 1 such as scratches. By making the surfaces of the rolls 4, 5, 7, 8 non-conductive, sparks can be prevented. Roll 4,
As the surface material of 5, 7, and 8, for example, an insulating ceramic such as alumina may be used. In particular, when the line speed is low, or when the heating temperature of the traveling strip-shaped metal material 1 is too high than that of the roll 5, the roll surface is preferably made of a material having an insulating property and a heat insulating property.
It may be made of a ceramic sintered body made of a material containing rO ₂ as a main component, thermal spraying, or the like.

Further, when the roll is guided by the magnetic flux leaking from the inductors 2 and 3 as described above, the magnetic flux to go to the object to be heated also passes through the roll side, and the heating efficiency is reduced. It is also assumed that the roll itself becomes hot and the strength is reduced. In such a case, the roll may be made of a material that is less likely to be guided, and for example, a non-magnetic material such as SUS304 or copper may be used.

Although the above description has been made with reference to the case of the vertical pass, if the tension can be set so as not to be affected by the catenary, the same effect can be obtained in the horizontal pass.

[0031]

Embodiments of the present invention will be described below with reference to the drawings. To confirm the effect of the present invention, a TF heating experiment was performed. The experiment was performed with an apparatus having the same configuration as that shown in FIGS. As material to be heated, thickness 0.2mm, width 300
Using a cold-rolled steel sheet of mm, heating was carried out at a line speed of ² to 20 mpm and a tension of 0.5 to 21 kg / mm ² from room temperature to 900 ° C. The power supply has a frequency of 3000Hz,
A capacity of 200 kw was used.

The inductor was formed by winding a square steel pipe of 40 mm × 30 mm around a laminated electromagnetic steel plate having a length of 500 mm, and the gap was set to 60 mm. The roll has a diameter of 2
Made of non-magnetic material SUS304 of 00 mm and body length of 500 mm (CA
SE1-5) When no surface treatment is applied to the surface (C
ASE5) was compared with a material obtained by spraying ZrO ₂ as an insulating material at 250 μm (CASE1 to CASE4), and a magnetic roll having a diameter of 200 mm and a body length of 500 mm made of S45C (CASE7) was used.

(CASE 1) Regarding the effect of meandering, heating was carried out with the configuration of FIG. In this example, an experiment was performed in which the coil was shifted from the normal position and set on a payoff reel, and a meandering was intentionally generated.

The roll 4 is separated from the inductor by 200 mm, and the whole roll can be moved up and down by 100 mm with a hydraulic cylinder around the center of the roll. Immediately after the roll 4, photoelectric tube type plate edge detecting devices 9 and 10 are provided so that meandering of the plate can be detected. Although not shown, the meandering detection information is sent to the hydraulic cylinder drive control device to control the stroke of the cylinder according to the meandering amount.

First, when induction heating was performed without performing meandering control, the steel sheet gradually shifted from the normal position of the inductor, and overheating of the steel sheet edge on the meandering side expanded, and finally the edge was melted. Was. Next, when the induction heating was performed while controlling the meandering using the meandering control device, the extreme overheating of the edge as described above did not occur.

(CASE 2) Heating was performed by the heating device according to the present invention shown in FIG. Roll position is 4,5,7,8
In each case, the roll was arranged at a position 200 mm away from the inductor, and each roll was placed 1 mm away from the center line. As a result, even when the tension was reduced, the steel sheet was slightly in contact with the inductor, and stable heating was possible. In particular, even at a low speed, since the heated steel sheet is unlikely to come into contact with the roll, there was almost no influence of heat removal by the roll.

(CASE 3) Heating was performed by the heating device according to the present invention shown in FIG. Roll 4 and roll 5 are 200mm apart from the inductor and 200mm above roll 4
And the roll 8 was set 200 mm downstream of the roll 5. In this case, even if the tension was reduced, the steel sheet was able to perform stable heating with little contact with the inductor.

(CASE 4) As a comparative example, heating was performed without disposing rolls before and after the inductor. In this case, even if the steel sheet was initially set so as to pass through the center of the inductor, the steel sheet was drawn to the inductor at the same time as the heating was started. When the steel sheet came closest, the portion was locally heated and the steel sheet was deformed. Such a state also occurs when the heating temperature is increased to a nonmagnetic region of 900 ° C. This is because there is always a magnetic region during the temperature rise to 900 ° C. In such a case, increasing the tension has little effect, especially when the magnetic material is heated from room temperature. There was a problem with the plate properties.

(CASE 5) The surface of the roll 4 is SUS3
Induction heating was performed in the same configuration as in CASE2 except that it was kept at 04. As a result, it was confirmed that a small spark was generated between the roll 4 and the steel sheet.

(CASE 6) The material of the roll 4 was made of carbon steel, and induction heating was performed in the same configuration as in CASE 2. As a result, it was confirmed that the roll 4 was heated outside the inductor and in contact with the steel sheet at room temperature.

Table 1 shows a list of the above results. The induction heating device according to the present invention is excellent in sheet-passing property and temperature distribution, and has no concern about generation of sparks, heating of rolls, and the like. Therefore, it was confirmed that stable heating was possible.

[0042]

[Table 1]

[0043]

According to the induction heating device of the present invention,
Even magnetic materials are not attracted to the inductor,
Stable heating becomes possible. Further, even if the material to be heated meanders, it can always be controlled to an appropriate position with respect to the inductor, so that an increase in temperature deviation due to the meandering can be avoided. Furthermore, since the occurrence of sparks between the steel plate and the roll due to the leakage magnetic flux and the heating of the roll itself can be avoided, high-quality heating can be stably performed without causing an accident or failure.

Further, since uniform heating by heating from the inside, which is a characteristic of electric heating, can be stably performed, it is not only optimal for heating requiring temperature controllability such as heat treatment, but also the heating rate can be freely adjusted. As a result, the degree of freedom of operation can be greatly expanded.

[Brief description of the drawings]

FIG. 1 is a side view illustrating an induction heating apparatus capable of controlling meandering and a pass line of a running strip-shaped metal material according to the present invention.

FIG. 2 is a side view illustrating an induction heating apparatus according to the present invention, which controls a pass line of a traveling strip-shaped metal material by a roll having a gap.

FIG. 3 is a side view for explaining an induction heating apparatus according to the present invention, which controls a pass line of a running strip-shaped metal material by rolls arranged in a longitudinal direction.

FIG. 4 is a front view illustrating a state in which induction heating is performed while performing meandering control according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Running strip-shaped metal material 2 Inductor 3 Inductor 4 Roll 5 Roll 6 Power supply 7 Roll 8 Roll 9 Position detecting device 10 Position detecting device

Claims (7)

[Claims] 1. An induction heating inductor disposed on both sides of a running belt-shaped metal material with respect to a running surface thereof,
In a device for heating a running strip-shaped metal material, a roll that contacts the strip-shaped metal material and regulates the pass-line of the strip-shaped metal material is provided on one of the input side and the output side of the inductor, and on the other side. An induction heating apparatus for a strip-shaped metal material, comprising: a roll that can be freely moved at least on one end side so that the strip-shaped metal material comes into contact with the roll. 2. A heating device according to claim 1, wherein a position detecting device for detecting a width direction position of the band-shaped metal material is provided upstream or downstream of the induction heating inductor. Heating equipment. 3. Using the induction heating device according to claim 2, the roll around which the band-shaped metal material is wound is moved based on the position information of the band-shaped metal material detected by the band-shaped metal material position detection device, and the band-shaped metal material is always moved. An induction heating method for a strip-shaped metal material, wherein induction heating is performed by controlling a positional relationship between a metal material and an inductor for induction heating in a width direction within a predetermined range. 4. An induction heating inductor disposed on both sides of a running belt-shaped metal material with respect to a running surface thereof,
In a device for heating a traveling strip-shaped metal material, a certain gap is formed in at least one of the inlet side and the outlet side of the induction heating inductor so that the traveling strip-shaped metal material passes through the center of the opposed inductor. An induction heating device for a strip-shaped metal material, wherein a pair of rolls are arranged to face each other. 5. An induction heating inductor disposed on both sides of a running belt-shaped metal material with respect to a running surface thereof,
In a device for heating a running strip-shaped metal material, a roll is formed on at least one of the inlet side and the outlet side of the induction heating inductor so that the running strip-shaped metal material passes through the center of the opposed inductor. An induction heating apparatus for a strip-shaped metal material, which is arranged so as to face each other at a constant interval in the longitudinal direction of the strip. 6. The induction heating apparatus for a strip-shaped metal material according to claim 1, wherein the roll surface is made of a non-conductive material. 7. The induction heating apparatus for a strip-shaped metal material according to claim 1, wherein the roll is made of a non-magnetic material.