JPS6119908B2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an induction furnace.

For example, in an induction furnace for melting metals, an induction coil is wound around the outer periphery of a crucible made of refractory material, and a yoke is placed around this outer periphery to serve as a path for the magnetic flux generated by the induction coil. It is supported by a structure.

Since the yoke of this type of conventional induction furnace is not equipped with a cooling mechanism, the yoke, especially the yoke plate, generates heat due to eddy currents caused by alternating magnetic flux. Therefore, in order to increase the power input to the furnace, the yoke becomes larger, its weight increases, the furnace body becomes larger, and as a result, the crane for transporting the induction furnace becomes larger and the building becomes larger. The problem was that the construction cost would increase.

This invention was made in order to solve the above-mentioned problem, and by making the yoke in an induction furnace water-cooled, it is possible to increase the magnetic flux density of the yoke. The purpose of this is to make the yoke smaller and lighter in comparison to the amount of power input, thereby making the entire furnace smaller and lighter.

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

In Figures 1 to 3, 1 is an induction furnace, 2
3 is a crucible made of monolithic refractory, 3 is a crucible 2
An induction coil is wound concentrically around the outer periphery of the induction coil 3, a plurality of yokes 4 are arranged around the outer periphery of the induction coil 3 so as to surround the induction coil 3, and 5 is a furnace frame to which the yoke 4 is fixed.

As shown in Fig. 2, each yoke 4 has an iron core 41 made of a large number of laminated silicon steel plates, and a yoke plate 4 from both sides of the iron core 41.
2 and 43 and fixed with stud bolts 45, and a water cooling pipe 44 in an arbitrary shape is tightly fixed to the outer peripheral surface of the yoke plate 42 by welding or brazing. Note that the yoke plate 4 and the water-cooled pipe 44 can be made of Cu-based metal.

In the induction furnace configured as described above, when alternating current is applied to the induction coil 3, an alternating magnetic flux flows to the material 10 to be melted in the crucible 2, and the material 10 to be melted is heated and melted according to the well-known principle of induction heating. Ru.

The yoke 4 forms a magnetic path for the alternating magnetic flux outside the crucible.

On the other hand, by flowing cooling water through the water cooling pipe 44, the heat generated in the yoke 4 is absorbed by the cooling water, and the rise in temperature of the yoke 4 is reduced. Furthermore, if the yoke plate and/or water-cooled pipe are made of a good thermal and electrical conductor such as aluminum, copper, or their alloys, heat generation due to eddy currents will be reduced, the water-cooling effect will be increased, and the yoke will become even more effective. temperature rise decreases.

As mentioned above, by water-cooling the yoke 4, the temperature rise is suppressed, so the magnetic flux density of the iron core 41 can be increased, and even if the cross-sectional area of the yoke 4 is made small, high power can be input to the induction coil. I can do it. The induction coil may be of a water-cooled tube as is known in the art.

As detailed above, according to the present invention, the yoke of the induction furnace is cooled by a water-cooled pipe to suppress the temperature rise of the yoke. The overall shape of the induction furnace can be reduced in size and weight. This prevents the size of the factory building in which the induction furnace is installed and the crane that transports the induction furnace from becoming large, thereby reducing equipment costs and the like.

Note that the water-cooled pipe may be provided in a meandering manner so as to pass through the iron core laterally in parallel with the stud bolts that stack and fix the iron cores.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the induction furnace of the present invention, Fig. 2 is a perspective view of a yoke used in the embodiment of Fig. 1, and Fig. 3 is a view from above of the embodiment of Fig. 1. FIG. 1... Induction furnace, 2... Crucible, 3... Induction coil, 4... Yoke, 41... Iron core, 42, 43...
Yoke plate, 44... water cooling pipe, 10... material to be melted.

Claims (1)

[Claims] 1. Wrap an induction coil concentrically around the outer circumference of the crucible,
Both ends of the laminated core are sandwiched between yoke plates on the outer periphery.
A plurality of split yokes are arranged at predetermined intervals in the circumferential direction of the crucible, and water-cooled pipes are welded or brazed to the outer surface of the yoke plate, and the water-cooled pipes are arranged between each of the yokes. An induction furnace characterized by being located within a gap.