FUEL INJECTION PUMP TO BE USED FOR INTERNAL COMBUSTION ENGINE

摘要

PURPOSE: To keep pre-injection quantity constant even at varying engine speeds and to attain an optimal reduction in combustion noise at various engine speeds in a fuel injection pump for an internal combustion engine. CONSTITUTION: A fuel injection valve 12 has a valve needle 37 controlling at least one outlet opening. The valve needle abuts a movable stop 64 against the spring force of a first valve spring 59 by means of fuel pressure in a closure direction. The valve stop is loaded by a second valve spring 63. The stop is lifted from a fixed stop 66 when fuel pressure is further increased. At an opening position of the valve needle 37 abutting a movable stop 64 contacting the fixed stop, the cross section area regulating at least the fuel flowing out from one outlet opening of the fuel injection valve is reduced as compared with the above cross section area of the movable stop lifted from the fixed stop when the fuel injection valve is completely open.