Piston for internal combustion engines
AssigneeKS Kolbenschmidt GmbH
InventorsVolker Gniesmer, Emmerich Ottliczky, Gunter Bayer
Life of this patent
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Abstract
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.
Claims15
A piston for an internal combustion engine that is designed as a single-piece piston including a combustion chamber recess and at least one cooling duct, the piston having a piston upper part and a piston lower part that are supported by matching joining webs connected material-to-material using multi-orbital friction welding, comprising:
- the combustion chamber recess and the cooling duct both located eccentrically by an axial offset with respect to the piston center axis and have one of an identically circular shape or deviating from a circular shape, where the piston upper part and the piston lower part are supported by the joining webs of at least approximately a same wall thickness.
A method for producing a piston for an internal combustion engine comprising:
- producing a piston upper part and a piston lower part as one of forged or cast blanks;
- pre-machining the piston upper part and the piston lower part that includes introducing a combustion chamber recess and cooling duct having an inner wall, the chamber recess and cooling duct positioned eccentrically by an axial offset with respect to a piston axis, a vertical portion of the cooling duct inner wall substantially following the contour of the chamber recess;
- joining components on the same axis, including the piston upper part and the piston lower part, whose eccentric combustion chamber recess and/or eccentric cooling duct, are realized by pre-machining, using centric multi-orbital friction welding.
Dependencies are inferred from the claim text.