Method for assembling and hardening a ball plug in a counterbore of a fuel injector nozzle assembly

Abstract

According to the method of the present invention, the ball plug is press fit into the counterbored passage of a fuel injector nozzle assembly prior to hardening of the fuel injector nozzle assembly. A core hardening and gas nitriding process is then applied to the assembly, causing the ball plug to expand and the passage diameter to shrink. This results in a greatly increased seal between the ball plug and the passage, and substantial elimination of the gaps experienced therebetween in prior art fuel injector nozzle assemblies

Dependencies are inferred from the claim text.