Abstract: A piston for an internal combustion engine has a lower piston part and an upper piston part that are connected with one another by friction welding and form an outer circumferential cooling channel. The upper piston part has a circumferential ring belt provided with ring grooves, the inner wall of which delimits the circumferential outer cooling channel. An outer circumferential friction-weld seam is provided below the ring belt, the width of which seam is less than or equal to the wall thickness between the groove root of the ring grooves and the inner wall of the ring belt.

Abstract: A piston for an internal combustion engine has a lower piston part and an upper piston part that are connected with one another by friction welding and form an outer circumferential cooling channel. The upper piston part has a circumferential ring belt provided with ring grooves, the inner wall of which delimits the circumferential outer cooling channel. An outer circumferential friction-weld seam is provided below the ring belt, the width of which seam is less than or equal to the wall thickness between the groove root of the ring grooves and the inner wall of the ring belt.

Abstract: The invention relates to a piston with a central cooling chamber. The cooling chamber is located beneath the piston head and is impinged upon by oil. At least the lower wall of the cooling chamber is formed by a plate. The purpose of the invention is to provide a means of fixing the plate to the piston as easily as possible. To this end, the piston has at least one second pin or clamping sleeve situated above the piston pin. The second piston pin or clamping sleeve has a smaller diameter, extends approximately in the direction of the piston pin axis, and is connected to the piston. The plate which forms the lower wall of the cooling chamber is supported against the second piston pin or clamping sleeve.