Cooling duct piston for an internal combustion engine
AssigneeKS Kolbenschmidt GmbH
InventorsVolker Gniesmer, Norbert Nies
Life of this patent
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Abstract
A method for producing a piston for an internal combustion engine, designed as a cooling duct piston for small compression heights. The piston includes a lower part and an upper part which are supported by one or more corresponding joining planes and are connected of a friction welding process. The piston encloses an inner, trough-shaped cooling duct and an outer cooling duct which is axially spaced apart from an annual area. The inner cooling duct is formed in the lower part of the piston by a mechanical machining process, such as a forging process. Transfer openings which are assigned to the cooling ducts are formed before the frictional welding of the joining planes.
Claims14
A method for producing a piston for an internal combustion comprising the steps of:
- forming at least two cooling ducts, which enclose a lower part and an upper part supported by at least one corresponding joining plane and connected by means of a joining process;
- forming, in an area above a piston pin bore, the at least two cooling ducts including an inner cooling duct produced by one of a mechanical machining, forging and casting having a trough-shaped area, and an outer cooling duct which is spaced apart from an annular area of the piston;
- forming the inner cooling duct with at least one transfer opening to the outer cooling duct which opens into the trough-shaped area of the inner cooling duct and at least one transfer opening which opens into the interior of the piston;
- and
- forming of the at least one transfer openings before the joining of the at least one joining plane.
claim, :
- locating the inner and outer cooling ducts partially in the lower part and partially in the upper part of the piston.
, ;
- enclosing the inner and outer cooling ducts enclosed by walls of almost equal wall thickness.
, :
- disposing the inner and outer cooling ducts in a spaced apart manner in the piston following a contour of a combustion bowl.
, assigning or the transfer openings to the inner and outer cooling ducts to the lower part of the piston.
A method for producing a single-piece, forged, cooling duct piston from steel for an internal combustion engine comprising the steps of:
- forming the piston to enclose at least one outer and one inner cooling duct;
- forming the piston to enclose an annular area which is brought into a final position by bending;
- forming by means of a mechanical machining process, and in conjunction with a cover element in an internal area of the piston, one of an inner cooling space and an inner cooling duct to which the radially spaced apart outer cooling duct is assigned;
- and
- connecting the outer cooling duct to the inner cooling duct inner cooling space by at least one transfer opening.
Dependencies are inferred from the claim text.