Fuel pump for an internal combustion engine

Abstract

A fuel pump for an internal combustion engine that transmits fuel with pressure by a lifting movement of a plunger that is caused to lift by a movement of a cam includes a lift amount changing mechanism. The lift amount changing mechanism includes a cam in which a height of a projection is varied along an axial direction of the camshaft, and a cam moving actuator that moves the cam along the axial direction of the camshaft. The lift amount of the plunger is changed by moving the cam along the axial direction of the camshaft. An amount of discharged fuel is controlled by changing the amount of discharged fuel per stroke of the plunger and is not determined only based upon the rotation speed of the engine. Therefore, the amount of discharged fuel can be increased with the engine rotated at a low speed, for example when the engine is being initially started, to improve a starting performance.

Dependencies are inferred from the claim text.