Patent ID: 7971355

Claim:
A method for attaching a ring element to a piston for an internal combustion engine, the piston having a basic piston body that forms a radially inner part of a piston crown, and having two pin bosses each connected with the piston crown by way of a pin boss support, which pin bosses are connected with one another by way of two skirt elements, wherein a ring element is connected with the basic piston body by way of a thread applied to a radially outer surface of the inner part of the piston crown, said ring element forming a radially outer part of the piston crown, and, together with the basic piston body, forms a circumferential cooling channel disposed radially on the outside and close to the piston crown, and wherein a lower face surface of the ring element comes into contact with a piston-crown-side surface of a circumferential molded-on part affixed to the radially outer surface of the piston, at a level of the pin boss supports, the method comprising the following steps: providing a projection on the molded-on part, said projection widening the piston-crown-side surface of the molded-on part radially to an outside; providing a radially outer edge of the inner part and a radially inner edge of the outer part of the piston crown with a bevel; screwing the ring element onto the basic piston body by way of the thread, wherein the two bevels of the inner and the outer part of the piston crown form a groove that is V-shaped in cross-section; filling the groove and covering a piston-crown-side surface of the projection with solder material; heating the piston until the solder material liquefies and flows between thread channels of the thread and between the lower face surface of the ring element and the piston-crown-side surface of the molded-on part; cooling the piston; and removing a part of the projection that projects beyond the radially outer surface of the ring element.