Continuous lubrication of extrusion dies - pref. using ring groove in die inlet so lubricant flows onto billet

摘要

The working surface of an extrusion die are continuously lubricated, the novelty being that the surface of the blank is locally lifted from the working surface to form a dead zone into which the lubricant is fed. The lubricant then flows onto the surface of the blank, and onto the working surface of the die, and is carried through the die. The pref. device employs =1 projection and =1 channel to feed a liq. or pasty lubricant onto the blank, esp. using a ring channel at the die inlet. Alternatively, several sickle-shaped projections may be used contg. holes leading to the working surface of the die. When a ring channel is used, it is pref. formed by an inner- and an outer- ring at the die inlet. The lubricant can be supplied without using very high pressures similar to the extrusion pressure, and extrusion speeds are increased, e.g. with Al alloys.