JPS58107418A - Apparatus for induction heating of billet - Google Patents

Abstract

PURPOSE:To effectively heat a billet without thermal deformation, by providing slits extending along the lengthwise and a plate extending along the lengthwise inside a cylindrical extruding rod to push the billet in an induction heating coil. CONSTITUTION:A series of many billets 3 are supplied from a material feeder 2 and fed through a chain conveyer 4 and a pinch roller 5 into an induction heating coil 6. When the billets 3 are completely carried out from the feeder 2, a means 7 for feeding an extruding rod into the coil 6 is driven to bring the top end of the extruding rod 1 into contact with a billet 3 at the final end and to push out the billets 3 from the coil 6. Accordingly, all the billets 3 including the last one are effectively heated at a predetermined temperature. By using the extruding rod 1 for the apparatus for induction heating the billets, a magnetic circuit is cut even in the coil 6 because of the formation of slits 13 so as to make heating small, and the thermal deformation of a pipe 10 can be inhibited because of the provision of a plate 11. In addition, a refractory material 12 poured into the pipe is effective in inhibiting the deformation of the pipe 10.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves feeding a large number of billets into an induction heating coil continuously at a predetermined speed using a conveying device such as a pinch roller, thereby reducing eddy current loss and hysteria caused in the billets placed inside the induction heating coil. Continuously conveyed billet induction heating equipment that heats this billet by heat loss, more specifically,
In the billet induction heating apparatus, the present invention relates to a push rod for pushing out the billet at the rear end, which cannot be pulled out of the induction heating coil by the above-mentioned conveying device, from the induction heating coil.

Conventionally, in this type of billet induction heating device, when the billet at the rear end remaining in the induction heating coil is pushed out of the induction heating coil using this type of extrusion rod, the extrusion rod is 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 once cut off to prevent heating, the billet F at the rear end will not be heated sufficiently and will often be scrapped. Also used is a cylindrical extruded copper rod with a linear slit extending longitudinally in order to cut the magnetic circuit. However, when using this extruded rod with a null, 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 rod and the axis center On the other hand, it is prone to bending, and may collide with the billet conveying bottle rower or the induction heating coil, interfering with the smooth billet pushing operation.

Various attempts have been made to improve the above-mentioned drawbacks regarding extruded rods, such as JP-A-54-20912 (extruded rod with 7 spiral holes) and JP-A-54-8.
The invention disclosed in Publication No. 1644 (water-cooled extrusion rod) can be mentioned. However, when a spiffle slit is formed on an extruded rod, although the linear slit does not bend too much during induction heating, the elongation becomes distorted and it is difficult to maintain an annular 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 comes into contact with the end surface of the extrusion rod.

The present invention eliminates the above drawbacks and uses an extruded rod that has a simple and stable structure, thereby preventing the extruded rod from being heated and deformed together with the billet by the electromagnetic induction action of the induction heating coil. It was done with the purpose of obtaining something.

In order to achieve all of these objectives, in the present invention, a slit extending in the longitudinal direction is formed in the cylindrical extrusion rod to reduce induction heating of the extrusion rod, and a plate extending in the longitudinal direction is provided in the extrusion rod. Increase the strength of the extruded rod and suppress its deformation. 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 plate within the extrusion rod be made of a non-magnetic material because hysteresis loss due to electromagnetic induction 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 compared to the case of one slit. The plates in the cylindrical push rod extend in the cross-sectional diameter of the push rod and may be joined to the inner surface of the push rod or extend to the outside surface of the push rod. When extending the plate to the outer surface of the extruded rod, cut the cylindrical extruded rod cross section into two parts in the diameter direction, insert the plate between the cut parts, and cut the cylinder Wl:S on both sides of the plate. It can be manufactured by joining and then forming a slit in the cylindrical part of the extruded rod in the vertical direction of the plates.

When using an extruded billet rod with the above structure, the extruded rod has a slit, so it is possible to use an induction heating coil! The eddy current loss in the extrusion rod due to magnetic induction is small, so heating is small, and the plate inside the extrusion rod suppresses its deformation even when heated, making it difficult for the extrusion rod to push the billet. It is possible to heat the last billet to a predetermined temperature without causing waste. Furthermore, the above extruded rod has a simple structure and can be easily manufactured.

EMBODIMENT OF THE INVENTION Hereinafter, several embodiments of the billet induction heating apparatus of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic explanatory diagram showing an example of a pinch roller type billet induction heating device. In Fig. 1, material supply device 2
A number of series of billets 3 are fed through a chain conveyor 4 and pinch rollers 5 to an induction 7Xl thermal coil.
- Sent to Ile 6. Billet 3 to material supply device 2
When the extrusion rod is exhausted, the extrusion rod feeding device @7 is activated, and the tip of the extrusion rod 1 comes into contact with the billet 3 at the rearmost end.
It is extruded from the induction heating coil 6. Therefore, with a conveying device such as a pinch roller, it is possible to effectively heat up to a predetermined temperature from the induction heating coil 6 to the billet at the rear end, which cannot be pulled out. After heating the last billet,
The pusher rod 1 returns onto the pusher rod feeding device 7.

FIG. 2 is a schematic explanatory diagram showing an example of a bushing-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 rear extrusion rod 1 is attached. When there are no more billets 3 in the material supply device 2, the extrusion rod 1 is moved forward greatly toward the induction heating coil 6 by the pusher 8, and the extrusion rod 1 is effectively extruded from the heating coil 6 to the induction heating coil 6. Heat to the specified temperature. When the pushing rod 1 reaches the forward end, the action of the pushing body fixing cylinder 9 is released and the pushing rod 1 returns to its original position.

An example of an extruded rod used in the billet induction 711 heating device 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. Extrusion rod l shown in Figures 3 and 4
A plate 11 made of a non-magnetic material extending in the longitudinal direction of the extruded rod and in the diametrical direction of the cross section is attached to the inside of the inner cylindrical pipe IO made of a non-magnetic material so as to be joined to the inner surface of the pipe 10. When the plate 11 is provided inside the pipe 10, deformation of the pipe 10 due to heating can be suppressed. pipe 10
There is also a refractory material 1 inside the pipe 10 to prevent deformation.
2 is filled. Two sleeves 18 and 13 are formed in the pipe 10 in the longitudinal direction of the extruded rod 1 for cutting the magnetic circuit in a direction perpendicular to the diametrical direction in which the plate 11 extends.

Another example of the extrusion rod 1 is shown in FIG. As shown in FIG. 6, the manufacturing process for the extruded rod l shown in FIG. 2. Insert a plate 11 made of material, join the cut portion of the pipe 10 to both ends of the plate 11, and then cut the magnetic circuit in the diametrical direction of the pipe in a direction perpendicular to the diametrical direction in which the plate 11 extends. book slit 13
11i is formed in the longitudinal direction of the extruded rod 1, and the pipe 10 is further filled with a refractory 12.

Therefore, when the extruded rod 1 in the billet induction heating device of the present invention is used, since the sleeve 1B is formed, the magnetic circuit is cut off even in the induction heating coil, so heating is small, and the strength of the pipe 10 is supplemented. Since the plate 11 is provided, deformation of the pipe IO can be prevented even by heating. 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 a 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 7Xl heating apparatus, and FIG. 2 is a schematic illustration of a bushing type billet induction heating apparatus. , FIG. 3 is a front view of the extrusion rod, FIG. 4 is a cross-sectional view taken along the line A-A in FIG. 8, FIG. 5 is a cross-sectional view showing another example of the extrusion rod, and FIG. FIG. 3 is a cross-sectional view showing the extruded rod during the manufacturing process. l... Extrusion rod, 2... Material supply device, 3...
・Billet, 4... Chain conveyor, 5.
... Pinch loaf, 6... Induction heating coil, 7.
・・Extrusion rod feeding device, 8・Butsusha, Discharge・Extrusion body fixing cylinder, IO・Pipe,
11...Plate, 12...Refractory, 13...Slit. Patent applicant: Fuji Electric Manufacturing Co., Ltd. Patent attorney: Aoyama Aoyama and two others Figure 1 Figure 2 Figure 3 Figure 4 I', Figure 5 Figure 6

Claims (1)

[Claims] 1. A slit extending in the longitudinal direction of the extrusion rod is formed in a cylindrical extrusion rod for pushing 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 by having an extensible plate attached. 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 plate 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 8, wherein the number of slits formed in the extrusion rod is two. 5. The billet according to any one of claims 1 to 4, wherein the plate within the cylindrical extruded rod extends in the diametrical direction of the cross section of the extruded rod and is joined to the inner surface of the extruded rod. Induction heating device. 6. The plate within the cylindrical extruded rod extends to the outer surface of the extruded rod in the cross-sectional diameter direction of the extruded rod and is joined to the cylindrical portion of the extruded rod.Claims 1 to 4 The billet induction heating device according to any one of paragraphs.