Simple frictional weld

Abstract

A cooling channel piston for an internal combustion engine which includes a piston bottom and a piston shaft that are joined thereto of a friction welding process. The piston bottom and the piston shaft jointly form a cooling channel. An annular wall which radially delimits the cooling channel towards the outside is formed by the piston bottom and/or the piston shaft. The annular wall can be sealed by a welding process once the piston bottom and the piston shaft have been joined together.

1 . The cooling channel piston for a combustion engine, comprising:
 a piston crown and a piston skirt attached thereto by means of a weld which together form a cooling channel:   a ring wall delimiting the cooling channel radially outward at least formed by one of the piston crown or the piston skirt and the ring wall closed to form a seal by one of an interference and a positive fit after piston crown and piston skirt have been joined; and   a face of the ring wall below a ring belt and an adjoining face of a ring side above the piston skirt both have a matching shoulder.   
     
     
         2 . The cooling channel piston of  claim 1 , wherein the ring wall is closed to form a positive fit by means of a another weld. 
     
     
         3 . The cooling channel piston  claim 1  wherein the face of the ring wall below the ring belt and the adjacent face of the ring side above the piston skirt are configured in the shape of a groove. 
     
     
         4 . The cooling channel piston of  claim 3 , wherein a circumferential groove in the lower face of the ring belt has a lesser depth (X) than a circumferential tongue has height (Y), the tongue ( 17 ) being deformable after the piston crown and piston skirt have been joined. 
     
     
         5 . The cooling channel piston of  claim 1  wherein in an inner area of the cooling channel piston at least one additional, radially circumferential web is disposed to form at least one additional cooling channel. 
     
     
         6 . The cooling channel piston of  claim 1 , where the weld is one of a friction weld and a resistance weld. 
     
     
         7 . The cooling channel piston of  claim 2 , wherein the another weld is a non-friction weld. 
     
     
         8 . The cooling channel of  claim 1 , wherein the face of the ring wall below the ring belt and the adjacent face of the ring side above the piston skirt have matching grooves.