Burr removing method and apparatus

#The present invention relates to a burr removing method and apparatus for removing burrs such as welding burrs and the like which are formed when, for example, billets and the like are subjected to butt welding in the continuous rolling of steel bars and the like.

#In conventional steel rolling lines, steel pieces such as billets, blooms and the like are rolled one by one and made to products. Recently, however, Japanese Unexamined Patent Publication Nos. 52-43754, 58-151971, 61-30287 and the like propose a method of subjecting a plurality of steel pieces such as billets and the like, which were extracted from a heating furnace, to flash butt welding and continuously rolling them to prevent the drop of a yield caused by the removal of the crop portions at the leading and trailing ends of the steel pieces and to increase productivity.

#When steel pieces are welded to each other by flash butt welding, welding burrs are formed to them at the welded sections thereof by the flash and pressure applied thereto. Since the welding burrs are relatively large, they act as flaws in the rolling operation carried out thereafter. Thus, there is a possibility that a yield is lowered by the flaws, and when the steel pieces are wires and like, there is a possibility that they are broken at the portions of the flaws while they are rolled. Accordingly, the welding burrs must be perfectly removed before the steel pieces are rolled.

#FIG. 1 is a schematic view of a conventional burr removing method.

#FIG. 2 is a schematic view of a burr removing method using a cutter having a polygonal cutting edge as an example of the present invention.

#FIG. 3 is a view showing the positional relationship between a cutter and a surface of a steel piece.

#As described above, a protruding burr is formed when a burr located at an edge of a steel pipe is cut by the cutting edge of a cutter through the force applied thereto by the cutter to cause the burr to be pushed out to the outside of the steel piece. Therefore, the occurrence of the protruding burr can be prevented when the burr is cut by the force applied thereto in such a manner that the force is directed inward of the steel piece in place of force for pushing out the burr outward from the edge of the steel piece.

#Burr removing methods of the present invention are based on this fundamental principle. Therefore, the present invention relates to methods of removing a burr located at an edge of a steel piece. While the methods of the present invention are applicable to a burr located in the interior of a steel piece, even if the burr is cut by another method, the effect of the present invention is not spoiled.

#FIG. 2 schematically shows a burr removing method using a cutter having a polygonal cutting edge as an example of the present invention.