| CPC F02M 59/025 (2013.01) [F02M 59/466 (2013.01)] | 15 Claims |
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1. A fuel pump for a gasoline direct injection fuel equipment of an internal combustion engine, comprising:
a housing provided with a pumping bore extending along a pumping axis and defining, at an end, a compression chamber which volume is cyclically varied by a piston reciprocating in said pumping bore;
an inlet passage in said housing in communication with a fuel supply passage;
an outlet passage in said housing, in which an outlet valve assembly is arranged and selectively discharges high pressure fuel;
an inlet valve assembly arranged in said inlet passage and configured to selectively allow low-pressure fuel to enter said compression chamber;
wherein said inlet valve assembly comprises:
a check valve comprising a seat member with at least one outlet passage therethrough cooperating with a valve member moveable between a seated position preventing flow through said at least one outlet passage and an unseated position permitting flow through the latter;
an actuator assembly comprising an actuating needle reciprocally moveable by means of a magnetic field to actuated said valve member between said seated and unseated positions, wherein said actuating needle is part of a needle assembly including an armature, a washer with a plurality of through holes and an obturating member,
wherein said obturating member comprises a plurality of flexible blades, each blade comprising an obturating pad configured to be moveable between a rest position, wherein said obturating pad rests on said washer and closes a respective through hole thereof, and a raised position, raised from said washer when said needle moves away from said check valve,
wherein each obturating pad comprises a plurality of openings, the cumulative cross-sections of the openings in a respective pad representing a fraction of the flow cross-section through the respective hole in the washer.
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