Extrusion tool for producing a hard metal rod or a ceramic rod with twisted internal boreholes

Abstract

The invention relates to a extrusion die tool for producing a hard metal or ceramic rod with at least one twisted internal bore (14). The nose (3) of the nozzle (2) has a smooth cylindrical channel (4). A bearer (6) is fitted coaxially inside the nozzle (2) which has a plurality of elastic threads (9) and/or channels or bores corresponding to the desired number of internal bores for the thread-shaped pressing of a plastic material into the extruded material. The bearer (6) and the nozzle nose (3) are rotary, i.e. they rotate about their longitudinal axes. The pitch of the twisted internal bores (14) produced is thus determined by the rotation speed of the thread bearer (6) and/or the nozzle nose (3) and the rate of flow of the extruded material. Rod blanks with high-precision helical internal bores (14) can thus be produced.

Dependencies are inferred from the claim text.