HIGH-PRESSURE FUEL-INJECTION PUMP Russian patent published in 2002 - IPC

FIELD: manufacture of engines; electronically-controlled fuel equipment. SUBSTANCE: high-pressure fuel-injection pump has housing, plunger pair with plunger without control edges, delivery pipe union with valve and control electromagnetic valve whose flow section connects suction chamber with above-plunger cavity simultaneously connected with delivery pipe line. Solenoid coil is arranged in pump housing between plunger pair and delivery pipe union coaxially to plunger; coil axis may be parallel to plunger axis. Fixed magnetic circuit consists of two parts embracing the coil simultaneously isolating it from fuel; they have fuel passages connecting the above-plunger cavity with delivery and suction chambers. Movable magnetic circuit (armature) is simultaneously used as hydraulic seal made in form of T- shaped hollow cylindrical bush and located coaxially inside coil in such way that cylindrical portion of larger diameter is received by coil at 1/3 of its height and diametral clearance not exceeding 0.2 mm and portion of smaller diameter is received by one of fixed magnetic circuits at clearance of 0.001 to 0.002 mm. EFFECT: enhanced reliability; increased speed of response. 3 cl, 1 dwg