JPS6033885B2 - Billet induction heating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims to reduce the eddy current loss that occurs in the billets placed in the induction heating coil by continuously feeding a large number of billets into the induction heating coil at a predetermined speed using a conveying device such as a pinch roller. and a continuous conveyance type pellet induction heating device that heats the billet by hysteresis loss.More specifically, in the billet induction heating device, the billet in the back weave, which cannot be pulled out from inside the yielding heating coil with the above-mentioned conveyance device, is removed from the induction heating coil. This relates to extruded camphor.

Conventionally, in this type of billet induction heating device, when pushing out the billet at the rear end remaining in the induction heating coil out of the billet induction heating coil using this type of extrusion rod, the extrusion rod was pushed together with the billet due to the electromagnetic induction action of the induction heating coil. If the electricity to the induction heating coil is temporarily cut off to prevent heating, the billet at the rear end will often be insufficiently heated and will be scrapped.

Also used is a cylindrical extruded rod with a linear slit extending in the longitudinal direction in order to cut the magnetic circuit. However, when this extruded rod with slits is used, the calorific value per unit volume is different between the part with slits and the part without slits, so a local temperature difference occurs in the extruded birch, and Easy to turn,
Collision with the billet conveying pinch rollers and induction heating coils may interfere with the smooth pushing of the billet. Various attempts have been made to improve the above-mentioned drawbacks regarding extruded rods, such as JP-A-54-20912 (extruded rod with spiral slit) and Tsubaki Kaisho 5.
The invention disclosed in Publication No. 4-31644 (water-cooled extrusion rod) can be mentioned.

However, when a spiral slit is formed in an extruded rod, although it does not bend as much as a linear slit during induction heating, the elongation becomes distorted and it is difficult to maintain the current shape. In addition, a water-cooled extrusion rod requires a large amount of cooling water, and is undesirable because it causes temperature unevenness in the billet portion that runs against the end surface of the extrusion rod. The present invention eliminates the above drawbacks and uses an extruded rod with a simple and stable structure, thereby preventing the extruded rod from being heated and deformed together with the billet by the electromagnetic transfer action of the induction heating coil. This was done for the purpose of obtaining a heating device.

In order to achieve this object, the present invention forms slits extending in the longitudinal direction in the cylindrical extrusion rod to reduce induction heating of the extrusion rod, and at constant intervals in the longitudinal direction of the extrusion rod within the extrusion rod. In order to increase the strength of the extruded rod, the rods are arranged alternately in the cross-sectional diametrical direction of the extruded rod, thereby increasing the strength of the extruding rod and suppressing its deformation.

If the rods are arranged alternately at regular intervals within the extrusion comb, the currents induced by the magnetic flux can cancel each other out. In order to further enhance the deformation suppressing effect of the cylindrical extruded rod, the inside of the extruded rod may be filled with a refractory.
It is preferable that the extrusion rod and/or the rod in the extrusion pole be made of a non-magnetic material because hysteresis loss due to electromagnetic conduction will not occur and heating will be reduced. If two slits are formed in the cylindrical extrusion rod at opposing portions in the cross-sectional diametrical direction of the extrusion rod, the eddy current loss in the extrusion rod can be further reduced than in the case of one slit. When an extruded billet rod with the above structure is used, since the extruded rod has slits, the eddy current loss in the extruded rod due to the electromagnetic induction action of the induction heating coil is reduced by 4.0 mm, and heating is small, and the inside of the extruded rod is Since the extrusion rods are arranged alternately at regular intervals in the longitudinal direction, their deformation is suppressed even when heated, and the billet pushing operation by the extrusion rods is not hindered, and the final billet is maintained at the specified temperature without wasting any waste. Can be heated.

Moreover, the above extruded rod has a simple structure and can be easily manufactured. EMBODIMENT OF THE INVENTION Hereinafter, several embodiments of the pillet induction heating apparatus of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a schematic explanatory diagram showing an example of a pinch roller type billet transfer heating device.

In FIG. 1, a number of series of billets 3 are fed from a material feeder 2 and fed through a chain conveyor 4 and a pinch loaf 5 to an induction heating coil 6. When there is no billet 3 in the material supply device 2, the extrusion rod feeding device 7 is activated, and the tip of the extrusion rod 1 comes into contact with the rearmost billet 3 and extrudes it from the induction heating coil 6. Therefore, it is possible to effectively heat to a predetermined temperature even the rearmost end of the induction heating coil 6, which cannot be pulled out from inside the induction heating coil 6 using a conveying device such as a pinch roller. After heating the last billet, the extrusion rod 1 returns to the extrusion rod feeding device 7. FIG. 2 is a schematic explanatory diagram showing an example of a push-type billet induction heating device.

In FIG. 2, a billet 3 is supplied from a material supply device 2, and is intermittently fed into an induction heating coil 6 by the operation of a pusher 8 to which a pusher rod 1 is attached at the rear. When the billet 3 is no longer in the material supply device 2, the extrusion rod 1 is transferred to the pusher 8 and the induction heating coil 6.
The billet 3 at the end of extrusion is effectively heated to a predetermined temperature from the induction heating coil 6 to the billet at the end of extrusion. When the push rod 1 reaches the forward end, the action of the push rod fixing cylinder 9 is released and the push rod 1 returns to its original position. An example of the extrusion rod used in the billet induction heating apparatus described above is shown in FIGS. 3 and 4.

FIG. 3 is a front view of the extrusion rod, and FIG. 4 is a cross-sectional view of the extrusion rod taken along line A--A in FIG. The extruded rods 1 shown in FIGS. 3 and 4 are arranged inside a cylindrical non-magnetic material pipe 10 at regular intervals in the longitudinal direction of the extruded rods, and are arranged in directions intersecting in the diameter direction of the cross section of the cylindrical pipe 10. A large number of plates 11 made of non-magnetic material are alternately arranged. By providing the rod 11 inside the pipe 10, deformation of the pipe 10 due to heating can be suppressed. A refractory material 12 is filled inside the pipe 10 to prevent the pipe 10 from deforming. Two slits 13, 13 for cutting the magnetic circuit are formed in the longitudinal direction of the extruded shank 1, facing each other in the diametrical direction of the pipe 10 in a direction different from the diametrical direction in which the rod 11 extends. The bars 11 arranged crosswise are 90 degrees apart from each other.
The slits 13 and 13 are arranged at different angles of the rod 1.
1 is formed at an angle of 450 degrees from the direction in which it extends. FIG. 5 shows the direction 1 of magnetic flux generated when the push rod 1 shown in FIGS. 3 and 4 is inserted into the induction heating coil 6.
4, and FIG. 6 is an explanatory diagram showing the direction 15 of current when the push rod 1 of FIG. 5 is viewed from the direction of the arrow EOB. Since the extruded rod 1 has rods 11 attached at regular intervals in alternate directions inside the pipe 10, when the extruded rod 1 is inserted into the induction heating coil 6, the magnetic flux that flows through the extruded rod 1 is induced. The currents are generated in directions 15 that cancel each other out, so that the heating of the extrusion rod 1 can be reduced. As explained above, when the extrusion rod 1 in the billet induction heating apparatus of the present invention is used, the slit 1
3 is formed, the magnetic circuit is cut off even within the induction heating coil, resulting in less heating, and the rods 11 are placed at regular intervals in the cross direction within the extrusion rod 1, so the current generated is small. cancel each other out, making it possible to further reduce the heating of the extrusion rod by 4. In addition, since the strength is supplemented by the rod 11 even during heating, deformation of the pipe 10 can be prevented.

As a result, the billet pushing operation by the push rod 1 can be heated to a predetermined temperature without any trouble and without waste until the last billet. The billet extrusion rod 1 according to the present invention can be applied to a pinch roller type or pusher type billet induction heating device.

[Brief explanation of the drawing]

The drawings show several embodiments of the billet induction heating apparatus of the present invention, and FIG. 1 is a schematic illustration of a pinch loaf type billet induction heating apparatus, FIG. 2 is a schematic illustration of a pusher type billet induction heating apparatus, Figure 3 is a front view of the extrusion rod;
Fig. 4 is a cross-sectional view taken along the line A-A in Fig. 3, Fig. 5 is an explanatory diagram showing the direction of magnetic flux generated when the extruded rod is inserted into the induction heating coil, and Fig. 6 is a cross-sectional view taken from the direction of arrow B in Fig. 5. FIG. 3 is an explanatory diagram showing the current direction within the extrusion pole as seen. 1... Extrusion rod, 2... Material supply device, 3... Billet, 4... Chain conveyor,
5...Pinch roller, 6...Induction heating coil, 7.
...Pushing rod feeding device, 8...Pusher, 9...Pushing rod fixing cylinder, 10...
...Pipe, 11 ... Rod, 12 ... Refractory, 13 ... Slit, 14 ... Magnetic flux direction, 15 ... Current direction. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. A slit extending in the longitudinal direction of the extrusion rod is formed in the cylindrical extrusion rod that pushes the billet into the induction heating coil, and a slit extending in the longitudinal direction of the extrusion rod is formed inside the extrusion rod. A billet induction heating device characterized in that rods are arranged alternately at regular intervals in a direction that crosses the cross-sectional diameter of the extrusion rod. 2. The billet induction heating device according to claim 1, wherein the inside of the cylindrical extruded rod is filled with a refractory material. 3. The billet induction heating device according to any one of claims 1 to 2, wherein the extrusion rod and/or the rod within the extrusion rod are made of a non-magnetic material. 4. The billet induction heating device according to any one of claims 1 to 3, wherein the number of slits formed in the extrusion rod is two.