Piston upper part of an assembled or welded piston with extended cooling spaces

A piston of an internal combustion engine configured as a single-piece, liquid cooled-piston, with a piston lower part and a piston upper part having a combustion chamber recess comprising:

• In the piston upper part an annular cooling channel connected by connecting channels to an inner cooling space, and having recesses configured as blind holes oriented in the direction of a piston head and forming cooling spaces;
• and
• the recesses widening conically, starting from the cooling channel, toward the piston head as far as a recess bottom of the respective recess.

A method for producing a piston upper part of a liquid-cooled piston of an internal combustion engine that is joined to a piston lower part, wherein the piston upper part has a combustion chamber recess and a cooling channel that is connected to a central inner cooling space and also connected to a plurality of recesses oriented in the direction of and widening conically toward a piston head and configured as blind holes, comprising;

• inserting a casting mold member matching the shape of the plurality of recesses in a mold intended for the piston upper part prior to a casting process;
• and
• following completion of the casting and chilling of the piston upper part removing the casting mold member by purging.

A method for producing a single-piece, liquid-cooled piston of an internal combustion engine having a piston upper part and a piston lower part, wherein the piston upper part has a combustion chamber recess and a cooling channel that is connected to a central inner cooling space and also connected to a plurality of recesses oriented in the direction of and widening conically toward a piston head configured as blind holes, comprising:

• inserting a casting mold member matching the shape of the plurality of recesses in a mold intended for the piston upper part prior to a casting process;
• and
• following completion of the casting and chilling of the piston upper part removing the casting mold member by purging.

A method for producing a piston upper part of a liquid-cooled piston of an internal combustion engine that is joined together with a piston lower part, wherein the piston upper part has a combustion chamber recess and a cooling channel that is connected to a central inner cooling space and also connected to a plurality of recesses oriented in the direction of and widening conically toward a piston head and configured as blind holes comprising:

• forming the recesses in the piston upper part by means of mechanical, three-dimensional machining.