Welded piston assembly

摘要

A pre-finished piston part is disclosed that may be used to form a piston assembly. A pre-finished piston may include a lower part defining a piston axis, the lower part having a skirt and forming a lower surface of a cooling gallery. The lower part may include a radially inner bowl surface defining a lower part radially inner mating surface. The pre-finished piston assembly may further include an upper part having a radially outer bowl surface meeting the radially inner bowl surface at a radially inner joint. The upper part may include a radially inner wall defining a radially inner upper part mating surface. The radially inner wall may define a radially inwardly facing surface that defines a non-parallel angle with the radially inner bowl surface where the radially inner bowl surface meets the radially innermost edge of the radially inner mating surface.

主权项

1. A pre-finished assembly for making a piston, comprising:
a lower part defining a longitudinal axis, the lower part having a skirt and forming a lower surface of a cooling gallery, the lower part having a radially inner bowl surface defining a lower part radially inner mating surface, the radially inner bowl surface extending from a radially innermost edge of the radially inner mating surface toward a center portion of the assembly, the lower part including a radially outer wall defining a radially outer mating surface; and an upper part having a radially outer bowl surface meeting the radially inner bowl surface at a radially inner joint, the upper part including a radially inner wall defining a lower surface extending radially to define an upper part radially inner mating surface, the radially inner wall defining a radially inwardly facing surface leading upwardly away from the upper part radially inner mating surface, the upper part including a radially outer wall defining an upper part radially outer mating surface; wherein the radially inwardly facing surface of the upper part defines a non-parallel angle with the radially inner bowl surface where the radially inner bowl surface meets a radially innermost edge of the radially inner mating surface of the upper part; wherein the upper part radially inner mating surface is defined by an upper part radially inner wall having a first radial width corresponding to the upper part radially inner mating surface and wherein the radially inner bowl surface of the lower part defines a second radial width greater than the first width.