Hollow piston for a piston engine and method for producing a hollow piston

Process for manufacturing a hollow piston (1) for a piston engine, having a closed annular cavity (9), comprising the following process steps:

• constructing a first piston part (1a) with a diametral oversize (x) with a base section (3) from which a joint part (4), or a material extension for the said joint part (4), extends in one axial direction, and from which a peripheral wall (6) that delimits the annular cavity (9) on the outside and a mandrel (7) that delimits the annular cavity (9) on the inside extent in the other axial direction, in one piece in each case,
• constructing a second piston part (8) with a diametral oversize (x) in the form of a cover (8),
• connecting of the first and second piston parts (1a, 8), by friction welding,
• and finally machining of the superficies (18) of the hollow piston (1) or of the joint part (4), wherein the first piston part (1a) with the peripheral wall (6) and mandrel (7) are formed by sintering.

Process for manufacturing a hollow piston (1) for a piston engine, having a closed annular cavity (9), comprising the following process steps:

• constructing of a first piston part (1a) with a diametral oversize (x) with a base section (3) from which a joint part (4), or a material extension for the said joint part (4), extends in one axial direction, and from which a peripheral wall (6) that delimits the annular cavity (9) on the outside and a mandrel (7) that delimits the annular cavity (9) on the inside extend in the other axial direction, in one piece in each case,
• constructing a second piston part (8) with a diametral oversize (x) in the form of a cover (8),
• connecting the first and second piston parts (1a, 8), by friction welding,
• and finally machining of the superficies (18) of the hollow piston (1) or the joint part (4), wherein the cover (8) is constructed with a peripheral wall section (6a) that delimits the annular cavity (9) on the outside, and with a mandrel section (7a) that delimits the annular cavity (9) on the inside, and the peripheral wall section (6a) and the mandrel section (7a) are simultaneously formed on the cover (8) and the first piston part (1a) with the peripheral wall section (6b) and mandrel section (7b), and the second piston part (1b) with the peripheral wall section (6a) and mandrel section (7a), are selectively formed by sintering.

Process for manufacturing a hollow piston (1) for a piston engine, having a closed annular cavity (9), comprising the following process steps:

• constructing a first piston part (1a) with a diametral oversize (x) and with a base section (3) from which a joint part(4), or a material extension for the said joint part (4), extends in one axial direction, and from which a peripheral wall section (6b) that delimits the annular cavity (9) on the outside and a mandrel section (7b) that delimits the annular cavity (9) on the inside extend in the other axial direction, in one piece in each case,
• constructing a second piston part (1b) with a radial oversize (x) in the form of a cover (8) with a peripheral wall section (6a) that delimits the annular cavity (9) on the outside, and with a mandrel section (7a) that delimits the annular cavity (9) on the inside, said first piston part (1a) and said second piston part (1b) being formed from identical prefabricated parts,
• connecting the peripheral wall sections (6a, 6b) and the mandrel sections (7a, 7b), by welding,
• and finally machining of the superficies (18) of the hollow piston (1) or else of the joint part (4), wherein the peripheral wall sections (6a, 6b) and the mandrel sections (7a, 7b) are each constructed with an equal axial length.