JPS6349880B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an induction heating apparatus that makes it possible to directly roll a continuously cast material having an H-shaped cross section (hereinafter referred to as an H-shaped beam blank).

H-shaped steel was manufactured by heating and rolling the bloom, but recently the method has been to manufacture H-shaped beam blanks, reheat them on a separate line or factory, and then finish roll them. Summer. However, since the H-beam blank is cooled to atmospheric temperature before rolling, it is currently heated once more in a heating furnace to a uniform temperature of about 1150°C before being sent to the rolling material. The reason why so-called direct rolling, which uses the residual heat of continuous casting to continue rolling, is not possible is because the temperature distribution of the H-beam blank is highly uneven due to the heat dissipation caused by its special shape. This is because the temperature becomes too low and the rolling temperature drops significantly, making it difficult to partially reheat and roll to a uniform rolling temperature. If direct rolling becomes possible by partial heating, there will be disadvantages not only in terms of energy saving due to cooling to room temperature and then reheating, but also disadvantages in terms of resource saving due to an increase in the amount of surface oxidation of the rolled material. It is possible to solve the disadvantages in terms of labor saving due to continuous work.

This invention was made in view of the above points, and
The purpose of this project is to provide a device that saves energy, resources, and labor by performing direct rolling by locally heating the parts where the temperature has dropped too much without cooling the shaped beam blank after continuous casting. ing.

An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 to 5, reference numeral 1 denotes an H-shaped beam blank which is a heated object, and has a flange 11 and a rib 12.
111 is the end face of the flange 11,
112 is the outer surface of the flange 11.

2 is an iron core, which has legs 21 facing the end surface 111 of the flange 11 and an outer surface 112 of the flange 11.
the leg 22 facing the and the leg leg 21,
It is composed of a joint part 23 that connects 22. 3 is a heating coil wound around the leg 22, 4 is a power source to which the heating coil 3 is connected, 5 is a magnetic flux, and 51 is an end face 1.
11 and the leg 21.

A refractory material 6 protects the iron core 2 and heating coil 3 from the high temperature H-beam blank 1. 7 is an inductor consisting of an iron core 2, a heating coil 3, and a refractory material 6.

Next, the action will be explained. The internal temperature characteristics immediately after continuous casting of the H-shaped beam blank 1 are as follows.
As shown in the isothermal curve in the figure, the temperature is highest on the side of the flange 11 closer to the central rib 12, and the temperature decreases toward the end surface 111 of the flange 11, with the temperature decreasing most significantly along the outer surface 112. Therefore H
To reheat the shaped beam blank 1, see H in Figure 2.
There is a method of increasing the temperature mainly at the end of the flange 11, which corresponds to the shaded area in the cross section of the shaped beam blank 1, and providing a heat retaining means (not shown) to reduce the temperature drop of the rib 12 to make the temperature uniform. Be taken.

That is, as shown in FIGS. 3 and 4, the cross section of the iron core 2 is made E-shaped, and the width of the leg 22 facing the outer surface 112 of the flange 11 is widened so that the main magnetic flux 5 passes through the end of the flange 11. It is shaped so that it is close to the leg 21 facing the end surface 111. When the AC power source 4 is connected to the heating coil 3 wound around the leg 22 in this way, and the current is flowing in the direction shown in FIG. 3, a magnetic flux 5 is formed in the direction shown by the arrow A, and the current is reversed. Then, the magnetic flux 5 is also reversed and an alternating current magnetic flux is generated, which induces an induced current mainly at the end of the flange 11, and the H-shaped beam blank 1, which is continuously carried out onto rollers (not shown), is rotated as shown in FIG. Induction heating is performed along the pattern.

In addition, since the inductor 7 consisting of the iron core 2, the heating coil 3, and the refractory material 6 has a drive source (not shown) so that it can move in the direction of arrow B in FIG. It can be opened to inspect the inductor 7, and at the start of operation, a predetermined gap (usually 10 to 15
Start induction heating as close as possible (on the order of millimeters). On the other hand, if there is no guide to prevent the H-shaped beam blank 1 that is continuously carried out onto rollers (not shown) from bending or meandering in the direction of arrow B, the gap between the flange 11 and the inductor 7 is kept constant. It is also possible to install a device to maintain it. In this way, it is not only possible to eliminate uneven heating of the beam blank 1 in the carrying-out direction, but also to prevent damage caused by contact between the flange 11 and the inductor 7.

FIG. 6 is a diagram showing another embodiment of the present invention, in which two legs 22 are formed opposite to the outer surface 112 of the flange 11, and the heating coil 3 is wound around the legs 22. In this case, flange 1
This embodiment is characterized in that no magnetic flux leaks into the center of the outer surface 112 of the first embodiment, and the operation is the same as that of the above embodiment, so a description thereof will be omitted.

As described above, the induction heating device of the present invention has H
Since an induced current is applied to both ends of the flange of the H-shaped beam blank to partially heat it, the uneven temperature distribution of the H-shaped beam blank is eliminated and direct rolling is possible, resulting in energy savings. The effects of resource and labor saving can be achieved. In addition, heating of both ends of the flange is done by an induction heating device consisting of an integrated iron core, making it easier to adjust the distance between the flange and the iron core, compared to, for example, installing an induction heating device at each end of the flange. There are also other effects.

[Brief explanation of the drawing]

Figure 1 is an isothermal curve diagram showing the temperature distribution in the cross section of the H-beam blank immediately after continuous casting, Figure 2 is a cross-sectional diagram showing the heating pattern for directly heating the H-beam blank, and Figure 3 is the FIG. 4 is a sectional view showing the positional relationship between the H-shaped beam blank of the heating body and the iron core and heating coil according to an embodiment of the present invention; FIG. 4 is a partial perspective view of the iron core and heating coil according to an embodiment of the present invention; FIG. 5 is a sectional view showing the positional relationship between the H-shaped beam blank and the inductor, and FIG. 6 is a sectional view showing the positional relationship between the H-shaped beam blank and the iron core and heating coil according to another embodiment of the present invention. In the figure, 1 is an H-shaped beam blank, 11 is a flange, 111 is an end surface, 112 is an outer surface, 2 is an iron core, 21 is a leg, 22 is a leg, 5 is a magnetic flux, 51
is a magnetic path, and 3 is a heating coil. In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. An iron core consisting of at least three legs facing both end surfaces and an outer surface of a flange of a heated body having an H-shaped cross section, and a magnetic flux that is wound around this iron core and passes through both ends of the flange. An induction heating device characterized by comprising a heating coil that heats an end of the flange. 2. The induction heating device according to claim 1, wherein the iron core is configured to be movable toward the outer surface of the flange of the object to be heated.