Elimination of Secondary Injection in Diesel Fuel Injection

Abstract

The methods for eliminating secondary injection and cavitation have been investigated for highly rated diesel engines. Retraction characteristics of a delivery valve of a fuel injection pump have been particularly investigated theoretically and experimentally. The results of the above investigation are as follows. (1) The velocity and the duration of a delivery valve retraction should be suitably selected to avoid both secondary injection and cavitation. (2) Retraction velocity of a delivery valve should be as fast as possible at early stage of retraction and suitably shower at later stage to avoid elongation of injection duration and secondary injection respectively. (3) Two new type pumps have been developed with excellent injection performances free from secondary injection.