Fuel injection quantity adjustment apparatus for fuel injection pump

摘要

A pair of solenoids are disposed coaxially with and around a hollow cylindrical cut-off valve. The valve includes an inner non-magnetic sleeve and an outer permanent magnet sleeve. The cut-off valve slidably engages a fuel distributing plunger which injects fuel according to its axial reciprocation. The cut-off valve controls fuel injection quantity via timing of exposure of a fuel injection cut-off port in the plunger. When the pair of solenoids are energized in accordance with operating parameters of the engine, the cut-off valve is moved to a corresponding position along the plunger. A sensor senses the actual position of the cut-off valve for feedback control thereof. A pair of disc-like permanent magnets may be disposed opposite either extreme of travel of the cut-off valve in spaced relationship thereto. A pair of non-magnetic discs may be disposed in place of the pair of disc-like permanent magnets. A biasing member may be disposed between the cut-off valve and the plunger housing to prevent the cut-off valve from being attracted by the plunger housing and for preventing rotation of the cut-off valve relative to the plunger housing. The biasing member may be diaphragm, coil spring or a leaf spring.