Low thermal conductivity piston and method of construction thereof

摘要

A piston and method of construction are provided. The piston includes an upper crown having a combustion surface with an upper land depending therefrom and a lower crown having a pair of pin bosses that depend to a pair of laterally spaced, axially aligned pin bores. The upper crown is constructed as a monolithic piece of a first material having a thermal conductivity within a range of about 7 to 25 W/m-K. The lower crown is constructed from a low grade steel material having a thermal conductivity higher than the upper crown. The upper crown is joined directly to the lower crown, wherein the upper crown acts as a barrier to thermal conductivity and thus, the heat within a combustion chamber housing the piston for reciprocation therein is maintained and maximized.

主权项

1. A piston for an internal combustion engine, comprising:
an upper crown constructed as a monolithic piece of a 400 series or 600 series stainless steel having a thermal conductivity within a range of about 7 to 25 W/m-K, said upper crown having an upper combustion surface with an upper land depending therefrom, said upper land having at least one annular ring groove configured for receipt of a piston ring; and a lower piston portion welded directly to said upper crown, said lower piston portion being constructed of a low grade steel alloy material having a thermal conductivity higher than said upper crown, said lower piston portion having a pair of pin bosses providing a pair of laterally spaced, axially aligned pin bores.