Fuel injection device for diesel engine

摘要

A fuel injection device for a diesel engine adapted to perform a preliminary injection (1) and a main injection (2) to a combustion chamber (3), wherein the preliminary injection (1) is adjusted to begin within a valve overlap term (40). Within the valve overlap term (40), no intake air is introduced into the combustion chamber (3) or a little if any and the combustion chamber (3) contains a gas of high temperature. If the preliminary injection (1) is conducted into this gas of high temperature within the combustion chamber (3), a preliminary injection fuel vaporizes soon to thereby shorten the ignition lag of a main injection fuel with the result of improving the combustion.