摘要 |
A piston of an internal combustion engine, includes a piston upper part and a piston lower part which are supported via corresponding joining webs, in each case forming a joining zone connected in a material-to-material manner by means of a multi-orbital rotary friction weld. The joining webs and which are in each case directly connected have a wall thickness S1, S2 which is identical as far as possible. The piston encloses a combustion-chamber recess and at least one cooling duct which are made centrally or eccentrically in the piston. The combustion chamber recess and the cooling duct form a circular contour or a contour which deviates from a circular shape. |