Liell & McNeil
Electronic pressure relief in a mechanically actuated fuel injector
A mechanically actuated electronically controlled fuel injector includes a first electrical actuator that controls the position of a spill value, and a second electrical actuator to control pressure on a closing hydraulic surface associated with a nozzle check valve. The fuel injector is actuated via rotation of a cam to move a plunger to displace fuel from a fuel pressurization chamber either to a spill passage or at high pressure out of a nozzle outlet of the fuel injector for an injection event. Pressure in the fuel injector is moderated when the plunger is moving and the nozzle check valve is in a closed position by briefly cracking open the spill valve to relieve some pressure during the dwell between injection events, such as between a large main injection event and a small close coupled post injection event. This strategy allows for longer dwell times between injection events as well as smaller injection quantities in the post-injection.
Caterpillar Inc.
F F
F02M F02M
inventional inventional
Victor I. Dana R. Yongxiang
Yacoub Coldren Li