JPH02270287A - Heating of thin plate in induction heating apparatus - Google Patents

Abstract

PURPOSE:To heat the whole of a thin plate uniformly or with a prescribed temperature distribution by installing a plurality of pairs of cross magnetic flux-type tap-attached heating coils in transferring direction of the thin plate and either combining various coil widths the coils or modulating the gaps between the coils. CONSTITUTION:A plurality of pairs of cross magnetic flux-type tap-attached coils 2a, 3a, 2b, 3b are installed in transferring direction of a thin plate 1, and the taps of the coils 2a, 3a, 2b, 3b are switched by a tap switching apparatus 4 according to the width or material of the thin plate 1 and/or the gaps of the coils are modulated. Consequently, temperature distribution in the cross direction of the plate in induction heating of the thin plate 1 is modulated controllably and easily and thus temperature difference in the center and the end of the tin plate at heating is eliminated. As a result, heating in cross direction at high precision or heating with an optional temperature distribution in a prescribed cross direction can be carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application This invention relates to a method of heating a thin plate in a transverse magnetic flux type induction heating device.

B0 Summary of the Invention This invention provides a thin plate heating method in an induction heating device, in which multiple sets of transverse magnetic flux type tapped coils are provided in the conveying direction of the thin plate, and the taps of each coil are switched according to the material and width of the thin plate. By switching between coils, adjusting gears and brakes between coils, or a combination of both, it is possible to heat almost the entire thin plate uniformly or to a predetermined temperature distribution, regardless of the material, width, or thickness of the thin plate. This is how it was done.

C9 Conventional technology When heating a thin plate in a magnetic flux type thin plate induction heating device, conventional methods for improving the temperature distribution at the ends of the plate in the width direction include switching the winding width of the coil with a tap,
Various methods have been implemented to suit each coil shape, such as adjusting the core position, adjusting the amount of core stacking, and adjusting the position of the auxiliary heating conductor.

D1 Problem to be Solved by the Invention Among the above methods, in the spiral heating coil in the transverse magnetic flux type thin plate induction heating device shown in Figs. 10 and 11, when the plate width becomes narrower than the coil width, the plate It is known that overheating occurs at both ends. For this reason, the coil conductor A is
A measure is taken to avoid overheating of the plate ends by switching the taps from -D (A' to D') to A-C (A' to C'). At this time, if the plate width is between the coil conductor C and the coil conductor C (as shown in Figure 12), the coil conductor's plate ends will almost overheat, and the coil conductor C's plate ends will be underheated (underheated). ), causing a problem in which uniform heating in the width direction of the plate cannot be achieved.

In addition, in transverse magnetic flux type thin plate induction heating devices, in order to prevent magnetic flux leakage and increase heating efficiency, a first
An iron core as shown in Figure 3 is often arranged. By adopting such a configuration, the magnetic flux density of the portion where the iron core is arranged is increased, and the amount of heat generated by the plate immediately below the iron core is increased. Therefore, by arranging the iron core optimally with respect to the width of the plate, the temperature distribution in the width direction of the plate is adjusted to equalize the heat. For example, when the iron core is arranged as shown in Fig. 14, if the edge of the plate overheats, take steps to reduce the amount and length of the iron core Y as shown in the figure. Overheating can be avoided.

However, since the iron core Y surrounds the conductor Z and is provided directly on the conductor as shown in FIG. 15, it is difficult to reduce the number of iron cores Y by removing them or increase the number by adding them.

If the above-mentioned method is actually carried out, a problem arises that requires a great deal of time and effort.

This invention was made in view of the above circumstances, and when a thin plate is induction heated, the temperature distribution in the width direction of the plate is finely adjusted to eliminate the temperature difference between the center and both side edges of the thin plate. It is an object of the present invention to provide a heating method in an induction heating device that can uniformly heat or raise the temperature to a predetermined temperature distribution in the direction.

E8 Means for Solving Problems This invention provides a thin plate induction heating method for heating a conveyed metal thin plate with a transverse magnetic flux type induction heating device, which includes a plurality of sets of transverse magnetic flux type tapped heating coils in the conveying direction of the thin plate. are arranged, and the taps of each coil are switched by a tap changer to select a plurality of combinations of coil widths according to the width direction of the thin plate. The heating method may be such that the gap between the coils disposed facing each other on both sides of the thin plate is made variable, or a heating method that combines both the coil width combination using the tap switching device and the adjustment of the gap between the coils.

F6 effect When heating a thin plate with an induction heating device, if the width of the thin plate and the width of the heating coil are different, the taps of multiple coils are switched according to the width of the plate to adjust the width of each coil that is actually energized. By doing this, the temperature distribution in the width direction of the plate becomes uniform, and uniform heating of the thin plate is achieved. Further, the width of the heating coil remains constant relative to the width of the thin plate, and the distance between the coil and the thin plate (gear knob between the coils) is varied to make the temperature distribution in the width direction of the plate uniform.

Furthermore, the temperature distribution across the width of the thin plate can be made uniform by means of changing the tap of the coil according to the width of the thin plate, and by means of varying the gap between the coils.

G. Example An embodiment of the present invention will be described below based on the drawings.

[First Embodiment] In FIGS. 1A and B and FIG. 2, ■ is a thin plate, and multiple sets of transverse magnetic flux-type tapped heating devices are placed on both sides of the thin plate 1 in the conveyance direction of the thin plate 1 (in the direction of the arrow shown in the figure). Coils (spiral coils) 2a, 3a and 2b, 3b, . . . are arranged at regular intervals. heating coils 2a, 3a and 2b,
3b... is provided with a tap changer 4 as shown in Fig. 2, and switches the taps 5a, 5b, and 5c according to the plate width to change the actual coil width where each heating coil is energized. is adjusted. 6 is, for example, a heating coil 2a,
This is a power source that supplies heating power to 3a.

In the first embodiment configured as described above, when the tap of one heating coil is switched for a certain board width and the coil width to be energized is widened with respect to the board width, and conversely when it is narrowed. It is known that when the temperature distribution of the plate in the width direction is measured, it becomes as shown in Fig. 3 A, B, and C. That is, FIG. 3A shows the temperature distribution when the coil width is wider than the plate width, and in this case, the temperature at the ends of the plate in the width direction increases.

FIG. 3B shows the temperature distribution when the plate width and coil width match; in this case, the temperature distribution in the width direction of the plate is almost uniform. FIG. 3C shows the temperature distribution when the coil width is narrower than the plate width, and at this time the temperature at the ends of the plate in the width direction decreases.

When the thin plate is heated by switching the taps of the heating coil as described above, the temperature distribution of the thin plate is as shown in Figure 3A.

B, C. Therefore, as in the first embodiment, a plurality of heating coils 2a, 3a, 2b, 3b, . By selecting appropriate taps, it becomes possible to adjust the temperature distribution and temperature rise history very precisely.

For example, heating coils 2a, 3a and 2b with 2 taps
, 3b is used in the heating device shown in FIG. 4, and the temperature distribution in the plate width direction on the exit side of the thin plate l is shown in FIG. In FIG. 5, the temperature distribution a is the heating coil 2a.
, 3a and 2b.

The temperature distribution C is when the width of heating coil 2a, 3a and 2b is wide and only 3b is narrow.
3a is wide, 2b, 3b are narrow, temperature distribution d is widened by heating coil 2a, 3a, 2b, 3b
The temperature distribution e is the one when the width of all coils is narrower than the plate width. From this figure, if the taps of the two sets of heating coils 2a, 3a and 2b, 3b are varied appropriately, the temperature distribution in the width direction of the thin plate can be divided into five stages depending on the combination of the coil widths of the four coils in the two sets. By making fine changes, it is possible to adjust and equalize the temperature distribution (uniform heating in the width direction of the plate).

Figure 6 is a characteristic diagram showing the temperature history of the heating device at the termination and center of the heating device in Figure 4. In the figure, the solid line indicates the temperature history at the center of the plate, and the dotted line indicates the temperature at the side edges of the plate. It shows the history,
Heating coils 2a, 3a have a wider coil width, 2b, 3b
When the width of the heating coils 2a and 3a is narrowed, the dashed line shows the temperature history at the side edge of the plate, and when the coil widths of the heating coils 2a and 3a are narrowed, and those of 2b and 3b are widened. In this way, it is possible to prevent deformation of the thin plate by changing or adjusting the temperature history during heating by combining the coil widths of the respective coils.

In the above embodiment, the coil width switching tap is the first
As shown in FIG. A and FIG. 2, three or more stages may be provided, and three or more sets of tapped coils may be arranged in the conveying direction of the thin plate.

With this configuration, it is possible to create more combinations of heating conditions and more finely adjust the heating conditions at the center and side edges of the thin plate, thereby further improving the thermal uniformity in the width direction of the plate.

[Second Embodiment] In FIG. 7, a thin plate 1 is connected to a set of transverse magnetic flux type heating coils 11.
In this embodiment, the heating coils 11 and 12 shown in FIG. 7 are configured such that the coil spacing (gap) can be varied in the upper and lower directions. In Figure 7,
G is the case when the gap between the heating coils 11 and 12 is widened, and G is the case when the gap between the heating coils 11 and 12 is narrowed.

FIG. 8 shows a specific configuration of the embodiment shown in FIG. 7. In FIG. 8, heating coils 11 and 12 are attached to coil supports 13 and 14. Coil support 1
3.14 is screwed onto the screw shafts 15, 16, and the screw shafts 15.
16 rotates, the coil supports 13, 14 move up and down.

The screw shaft 15.16 is connected to motors 19, 20 via a gear box 17.18, and by driving the motors 19.20, the screw shaft 15.16 is driven. 2
1, 22, and 23 are flexible leads, and 24 is a power source that supplies power to the heating coils 11 and 12.

By changing the gap between the coils of a pair of heating coils using the variable heating coil mechanism shown in FIG. 8, it becomes possible to adjust the temperature distribution in the width direction of the thin plate 1. Uniform heating can be achieved.

Figures 9A, B, and C are characteristic diagrams showing the temperature distribution in the width direction of the thin plate when the above configuration is used. Figure 9A shows a wide gap between the coils (gap G1 shown in Figure 7). At this time, the temperature at the center of the adult cow is lower than the temperature at both ends of the board. Figure 9B shows the temperature distribution when the gap G is optimal, and Figure 9C shows the temperature distribution when the gap G is narrow (G shown in Figure 7). Rise.

As described above, in the method of the first embodiment, the temperature distribution mainly changes at both side ends of the plate, whereas in the method of the second embodiment, the temperature distribution mainly changes in the central part of the plate. Therefore, by combining the above-mentioned first and second embodiments, a transverse magnetic flux type heating coil with a plurality of sets of transverse magnetic flux type tapped heating coils and at least one set of coils in which the gap between the coils is made variable in the conveying direction of the thin plate. By arranging the heating coil and selecting the combination of the coil widths of multiple tapped coils, and adjusting the gear between the coils, the gear between the coils can be adjusted. Since the temperature distribution in the central part can be adjusted individually,
Furthermore, it becomes possible to adjust the temperature distribution in the board width direction with even higher precision. Furthermore, the range of plate widths that can be heated by the same heating coil can be increased.

In addition, when implementing the methods of the above-mentioned first embodiment and second embodiment in combination, in addition to the plurality of sets of heating coils with taps as described above, a coil with a variable gap between the coils may be arranged. Alternatively, the inter-fill gear knob of at least one set of the plurality of tapped heating coils may be made variable so that the coil width can be changed 9 and the gap between the coils can be adjusted.

Note that in both the first and second embodiments, the case where the thin plate 1 is conveyed in the horizontal direction is illustrated and explained, but the case where the thin plate 1 is conveyed in an upward or downward direction other than horizontally, etc. It can also be implemented in exactly the same way.

In addition, by performing induction heating on a thin plate using each of the methods described above, it is possible to inductively heat a thin plate with a uniform temperature distribution in the width direction of the plate. The thin plate can be induction heated with high precision using an arbitrarily set temperature distribution in the width direction, such as heating by setting the temperature higher at both end portions where a temperature drop is likely to occur.

Furthermore, it is known that the temperature distribution in the width direction of a thin plate during induction heating of a thin plate changes not only depending on the width of the plate but also depending on the material, thickness, etc. of the thin plate.

Even if the material or thickness of the thin plate changes, the temperature distribution in the width direction of the plate can be precisely adjusted and induction heating can be performed using the above-described method.

H0 Effects of the invention As described above, according to the invention, a plurality of sets of transverse magnetic flux type tapped heating coils are arranged in the conveying direction of the thin plate,
By combining various coil widths of each coil or adjusting the gap between coils of transverse magnetic flux type heating coils, temperature distribution in the width direction of a thin plate can be finely adjusted in a variety of ways. When heating a thin plate, it is possible to eliminate the temperature difference between the center and side edges of the plate, uniformly heating it in the width direction of the plate with high precision, or precisely setting any temperature distribution in the width direction of the plate set in advance. It is possible to heat and raise the temperature by matching well.

Furthermore, by combining the method of combining various coil widths and the method of adjusting the gap between the coils, it is possible to equalize the temperature in the sheet width direction with higher accuracy and to increase the heating temperature in accordance with a predetermined temperature distribution.

Furthermore, with the same heating coil device, the material and width of the thin plate,
Even if the plate thickness changes, you can select a combination of coil widths by changing the tap or adjust the gap between the coils to accommodate a wide range of changes. It is possible to perform heating to match the temperature.

[Brief explanation of drawings]

1A and 1B are a plan view and a side view showing a first embodiment of the present invention, and FIG. 2 is a schematic perspective view of a heating coil.
Figures 3A, B, and C are characteristic diagrams for explaining the operation of the first embodiment, Figure 4 is a side view showing examples of tap combinations in the first embodiment, and Figure 5 is the heating in Figure 4. FIG. 6 is a characteristic diagram showing the temperature distribution in the width direction of the plate on the exit side of the device; FIG. 8 is a side view showing the specific example of FIG. 7, FIG. 9 is a characteristic diagram for describing the operation of the embodiment of FIG. 7, and FIGS. 10 to 15 are conventional examples.
Fig. 10 is a plan view, Fig. 11 is a sectional view, Fig. 12 is an enlarged sectional view, Fig. 13 is a perspective view, Fig. 14 is a plan view, and Fig. 15 is a plan view.
The figure is a perspective view. 1-・Thin plate, 2a, 3a, 2b, 3b・=, 11°12
...Heating coil, 4...ta, knob switch. Fig. 1 1...Thin plates 2a, 2b Upper and lower coils 3a and 3b Lower and lower coils Fig. 3 Fig. 4 Fig. 5 Temporary central part! !・
Upper heating coil (side end)
12 ・Lower heating coil G,, Gt... Gap Fig. 8 13.14 Coil support 15.16 ・Screw shaft 17.18 ・Gear box 19.20 ・Motor 21.22.23 Flexino pull lead Fig. 9 10 Figure 2a-000 units 0 units 00 Figure 14 Figure 15 IY Z

Claims (3)

[Claims] (1) In a thin plate induction heating method in which a metal thin plate being conveyed is heated by a transverse magnetic flux type induction heating device, multiple sets of transverse magnetic flux type tapped heating coils are arranged in the conveying direction of the thin plate, and each coil is In an induction heating apparatus for thin plates, the combination of coil widths of each coil in the plurality of sets of heating coils is selected according to the material, width, and thickness of the thin plates by switching the taps using a tap changer. Heating method. (2) In a thin plate induction heating method in which a conveyed metal thin plate is heated by a transverse magnetic flux type induction heating device, the gap between the coils of the transverse magnetic flux type heating coils arranged oppositely on both sides of the thin plate is determined by the material of the thin plate and the plate width. , a method for heating a thin plate in an induction heating device, characterized in that the heating method is adjusted according to the thickness of the plate. (3) In a thin plate induction heating method in which a thin metal plate being conveyed is heated with a transverse magnetic flux type induction heating device, multiple sets of transverse magnetic flux type tapped heating coils are arranged in the conveying direction of the thin plate, and each coil is A tap changer for switching the taps is provided, and at least one set of heating coils among the plurality of sets of tapped heating coils, or further arranged in the plurality of sets of tapped heating coils in the conveying direction of the thin plate. The gap between the coils of at least one set of transverse magnetic flux type heating coils is configured to be variable, and the combination of coil widths of each coil in the plurality of sets of coils is selected according to the material, width, and thickness of the thin plate. A method for heating a thin plate in an induction heating apparatus, characterized in that the temperature distribution in the width direction of the thin plate is adjusted by adjusting the gap between the coils of the at least one set of coils.