JPS6125593Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a furnace structure in which a metal workpiece is passed through a tunnel formed in a heat-resistant material, and the workpiece is heated by high-frequency induction within the tunnel. The present invention is characterized in that the gap between the workpiece and the tunnel wall is reduced to improve heating efficiency.

For example, as a means of heating metal rods for forging, as shown in FIG. 2, metal workpieces 3, 3 are ... are pushed in one after another, the workpiece 3 is heated by the high-frequency dielectric action of a spiral coil 4 arranged around the tunnel wall 2a, and the workpiece is discharged to the other end of the tunnel. be. In this case, it is necessary to lay rails 5, 5 as shown in Fig. 3 in order to prevent the metal workpiece 3 from scraping the furnace cavernous wall. The gap 6 between the cave wall 2a and the workpiece 3 increases, and the electromagnetic induction efficiency in the workpiece 3 decreases. Moreover, since the rails 5, 5 are affected by radiant heat from the workpiece 3, it is necessary to flow cooling water inside them.

In view of the above points, this invention installs a tube of a type devised to prevent electromagnetic induction power generation in place of the rail inside the tunnel, thereby reducing the gap around the workpiece and heating the workpiece. It is.

An embodiment of the present invention will be described below with reference to FIG. In FIGS. 1A and 1B, a cylindrical furnace body 10 is connected to a predetermined base 1 via a predetermined number of legs 11.
It is fixed on 2. The furnace body 10 is made of a heat-resistant material such as heat-resistant cement, and has a predetermined length in the axial direction. Further, the furnace body 10 passes through a tunnel cave 13 having a circular cross section from one end to the other in the direction of its central axis, and a coil 14 is embedded within the furnace body so as to surround the cave 13. Furthermore, a metal tube 15 having approximately the same length as the furnace body is inserted into the cave 13. However, the tube 15 has a discontinuous cross section, and a slit 16 is formed from one end to the other end.

The illustrated embodiment is configured as described above,
Existing within the tube 15 is a workpiece A made of a round metal bar. A large number of workpieces A... are pushed into the tube 15 one after another from one end and extruded to the other end, while electromagnetic induction power generation occurs within the metal workpiece A due to the high frequency dielectric action in the coil 14. The workpiece A is heated by the induced current. In this case, the tube 15 with a discontinuous cross section
Since the tube has a so-called dielectric cut shape, no induced current flows in the tube, so that the workpiece A is heated but the tube 15 is not heated.

Note that in the drawing, the tunnel cave 13 and the tube 15 are each shown to be circular to match the shape of the workpiece A, but if the workpiece is square, the tunnel cave and tube 15 may be squared to match the shape. It is natural to do so.

As mentioned above, in the electromagnetic induction heating furnace of the present invention, a metal tube 15 with a discontinuous cross section, in which a slit 16 of a predetermined width is formed from one end to the other end, is installed in the tunnel cave 13 in the furnace body, and the tube and The workpiece A, which has the same cross section, is moved within the same tube and heated by induction power generation, making it possible to reduce the gap between the tube 15 and the workpiece A, which is different from the conventional rail. The heating efficiency is improved compared to the formula, and on the other hand, the electromagnetic induction cut-shaped tube 15 itself does not generate heat, and has a large contact area with the furnace body 10, so heat is absorbed by the furnace body.
It is not heated even by radiant heat from workpiece A,
Therefore, it does not require a cooling structure using cooling water, and has the advantage of exhibiting durability even with a thin and simple structure.

[Brief explanation of the drawing]

FIG. 1A is a front sectional view showing an embodiment of the present invention;
FIG. 1B is a side sectional view of the previous figure, FIG. 2 is a side view showing a conventional example, and FIG. 3 is a sectional view taken along the line -- of the previous figure. A... Workpiece, 10... Furnace body, 13... Tunnel cave, 14... Coil, 15... Tube, 16... Slit.

Claims (1)

[Scope of utility model registration request] A tunnel cavern 13 is drilled through the heat-resistant material from one end to the other end, and a spiral dielectric coil 14 is provided in the heat-resistant material so as to surround the tunnel cavern.
In the cylindrical furnace body 10 in which a cylindrical furnace body 10 is buried, a slit 16 of a predetermined width is formed in the tunnel cavern 13 and has a cross-sectional shape that matches the cross-section of the tunnel cavern, that is, a discontinuous cross-section. An electromagnetic induction heating furnace characterized by having a metal tube 15 installed therein.