Two-part piston for an internal combustion engine

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).