초록 ▼

A fuel injector unit pump, driven by a cam function to supply fuel to an injector for an injection event. The fuel injector unit pump includes a body and a pumping plunger reciprocably disposed within the body and has a driven end. A cam follower assembly is provided for engaging the cam and include

A fuel injector unit pump, driven by a cam function to supply fuel to an injector for an injection event. The fuel injector unit pump includes a body and a pumping plunger reciprocably disposed within the body and has a driven end. A cam follower assembly is provided for engaging the cam and includes an advance piston that engages the driven end of the pumping plunger for advancing or retarding the timing of the injection event. The advance piston is movable in response to fluid pressure controlled by an advance control. A follower return spring is disposed between the body and the cam follower assembly and a plunger return spring is mounted coaxially with the follower return spring and between the body and the advance piston. The advance piston includes a main cavity and the cam follower assembly includes a housing and the fuel injector unit pump may also include a balance spring disposed between the main cavity of the advance piston and the housing of the cam follower assembly.

대표청구항 ▼

1. A fuel injector unit pump being driven by a cam and functioning to supply fuel to an injector for an injection event, comprising:a body; a pumping plunger reciprocably disposed within the body and comprising a driven end; a cam follower assembly engaging the cam and comprising a cam follower body

1. A fuel injector unit pump being driven by a cam and functioning to supply fuel to an injector for an injection event, comprising:a body; a pumping plunger reciprocably disposed within the body and comprising a driven end; a cam follower assembly engaging the cam and comprising a cam follower body defining an advance piston bore, an advance piston which engages the driven end of the pumping plunger for advancing or retarding the timing of the injection event, the advance piston being movable in said advance piston bore relative to said follower body in response to fluid pressure controlled by an advance control, said advance piston comprising bleed means for relieving said fluid pressure; a follower return spring disposed between the body and the cam follower assembly; and a plunger return spring nested with the follower return spring and between the body and the advance piston.