VERFAHREN ZUR MONTAGE UND ZUR FERTIGBEARBEITUNG VON PULVERMETALLURGISCH VORGEFERTIGTEN VENTILSITZRINGEN

摘要

The method concerns mounting and finish shaping of valve seat ring blanks produced by powder metallurgy, with this operation taking in their working position in a seat at the beginning of a gas channel in the cylinder head of an internal combustion engine made of a light alloy. The method is characterised by the fact that a ring blank (1) produced by powder pressing and sintering is introduced with a clearance into a bore by means of a roller tool (4), is then radially expanded by rolling until it is held by the bore wall, and possesses the required dimensions and density. The ring blank (1) is compacted by means of a roller set (6) with a cylindrical envelope to produce finish dimensions corresponding to the wall of the gas channel. A second roller set (8) with a conical envelope on the rolling tool (4) produces further compacting of the ring material, and a valve seat on the free internal edge of the ring with a given angle (45 or 60 deg.). Alternatively, the rolling tool is provided with additional profiled rollers to achieve the required compacting, and to produce given main and auxiliary seating surfaces.