Patent ID: 8225765

Claim:
Two-part piston ( 1 , 1 ′, 1 ″) for an internal combustion engine, consisting of a piston base body ( 2 , 2 ′, 2 ″) and a ring element 3 , 3 ′, 3 ″), wherein the piston base body ( 2 , 2 ′, 2 ″) has a round, essentially plate-shaped center part ( 9 , 9 ′, 9 ″), the radial diameter of which is at least approximately identical with the radial diameter of the piston ( 1 , 1 ′, 1 ″), wherein two skirt elements ( 10 ) that lie opposite one another and two pin bosses ( 11 ) that lie opposite one another and connect the skirt elements ( 10 ) with one another are formed onto the underside of the center part ( 9 , 9 ′, 9 ″), and wherein a circumferential ring rib ( 15 ), set back in the direction of the piston axis ( 6 ) relative to the radially outer edge of the center part ( 9 , 9 ′, 9 ″), is formed onto the top of the center part ( 9 , 9 ′, 9 ″), which rib forms the radially outer delimitation of a combustion bowl ( 16 ), wherein the ring element ( 3 , 3 ′, 3 ″) has a ring belt ( 5 ) on its radial outer surface, and wherein the ring element ( 3 , 3 ′, 3 ″) is soldered to the piston base body ( 2 , 2 ′, 2 ″) by way of an upper solder connection ( 23 , 32 ) having the length b, which is disposed on the radial inside of a piston crown ( 4 ) formed at least in part by the ring element ( 3 , 3 ′, 3 ″), and by way of a lower solder connection ( 24 , 24 ′, 33 ) having the length c, which is disposed radially outside on the top of the center part ( 9 , 9 ′, 9 ″), wherein the ring element ( 3 , 3 ′, 3 ″) has, for one thing, a circumferential, upper, thinned wall region ( 49 ) in the region of the piston crown ( 4 ), radially outside of the upper solder connection ( 23 , 32 ), and, for another, a circumferential, lower, thinned wall region ( 50 , 50 ′) between the ring belt ( 5 ) and the lower solder connection ( 24 , 24 ′, 33 ), wherein the thickness (a, d) of the thinned wall regions ( 49 , 50 , 50 ′) has a lower value than the length (b, c) of the solder connections ( 23 , 24 , 24 ′, 32 , 33 ).