Electromagnetic unit fuel injector with cartridge type solenoid actuated valve

摘要

An electromagnetic unit fuel injector for use in a diesel engine includes a housing with a pump therein defined by an externally actuated plunger reciprocable in a bushing and defining therewith a pump chamber open at one end for the discharge of fuel to a spring biased, pressure actuated fuel injection nozzle. The pump chamber is also connected to a first chamber via a solenoid actuated, normally open, hollow pressure balanced poppet valve controlled passage to permit the ingress and egress of fuel. The first chamber adjacent to one end of the valve is in flow communication with a second chamber at the opposite end of the valve and these chambers are connected to a drain passage and supply passage, respectively. During a pump stroke, the solenoid can be energized to move the valve in position to block flow from the pump chamber to the first chamber so as to allow the pressurization of fuel by the pump to effect discharge of fuel from the injection nozzle. In a preferred embodiment the solenoid actuated poppet valve is a cartridge type assembly which is adapted to be received in a suitable socket provided for it in the housing and to be secured therein in hydraulic sealed relationship.