Patent ID: 6062497
Filing Date: 2000-05-16
Classification: F02M

Abstract:
A fuel injector comprising:an injector body having a fuel pressurization chamber that opens to a fuel supply passage and a nozzle supply passage, and having a nozzle chamber that opens to a nozzle outlet and said nozzle supply passage;a portion of said fuel supply passage being a return spring cavity;a check valve positioned in said fuel supply passage between said return spring cavity and said fuel pressurization chamber and being operable to prevent flow of fuel from said fuel pressurization chamber back into said return spring cavity;a needle check positioned to reciprocate in said nozzle chamber between a closed position that closes said nozzle outlet and an open position that opens said nozzle outlet, said needle check including at least one hydraulic lift surface exposed to said nozzle chamber;said return spring cavity being defined at least in part by one end of said needle check, an end wall and a shoulder stop surface;a return sprint compressed in said return spring cavity between said one end of said needle check and said end wall;said one end of said needle check being in contact with said shoulder stop surface of said return spring cavity when said needle check is in said open position but being separated from said shoulder stop surface when said needle check is in said closed position;said needle check including an elongated needle valve member and a cylindrical spacer in contact with one end of said needle valve member;said one end of said needle check being one side of said spacer; andsaid injector body includes a relatively thin block defining a bore therethrough sized to receive said spacer.