| 摘要 |
<p>Apparatus for the continuous extrusion of metals in which feed is introduced into two (or more) spaced apart circumferential grooves (4) in a rotating wheel (2) (or rotating wheels) to contact an arcuate shoe portion (8) and abutments extending into the grooves. The feed is constrained by the abutments to flow through frusto-conical exit apertures (10) in the shoe portion (8) to a chamber (6) and is extruded as relatively thin-walled, large cross-section, product. The exit apertures (10) have cone angles in the range 5°-45°. Mixer plates (14) are profiled to distribute flow evenly from the apertures (10) to around the die opening (30). An extrusion die body (18) for cylindrical extrusions is located and axially centered by set screws (122). Where an even number of grooves (4) are utilised, an extrusion mandrel (12) may be secured to the shoe portion (8) by a bolt (22) positioned centrally of the grooves. Lubricant or oxidation inhibiting fluids may be injected internally of the extruded product through a passage (36, 38) extending through the shoe portion (8) and the bolt (22). In another embodiment, the chamber (6) is also of divergent frusto-conical form having a cone angle corresponding to that of the apertures (10), thereby enabling the extrusion of even larger cross-section products. The frusto-conical form may be of elliptical cross-section to achieve a requisite divergence or to accord with the configuration of the die orifice. By providing spaced apart grooves (4) and apertures (10) diverging frusto-conically it is possible to extrude products of relatively large cross-section since the volume feed rate is enhanced and the distance travelled by the material from the grooves (4) to the die orifice (30) is reduced, thereby reducing friction losses and the likelihood of discontinuities in the extrudate arising.</p> |
