PRE-MAIN-POST INJECTION FUEL DEVICE FOR A DIESEL ENGINE

摘要

PURPOSE: A multi-stage fuel injection system for a diesel engine is provided to improve combustion performance by controlling the generation of nitrogen oxide. CONSTITUTION: A multi-stage fuel injection system for a diesel engine comprises a needle body(14), a needle shaft(16), a pressure adjusting shaft(18), a first pipeline(26), a fuel chamber(36), a second pipeline(38), a third pipeline(40), and an elastic member(42). The needle body is fixed to the bottom end of a valve body(12). First and second injection ports(20,22) are formed in the top and bottom of the needle body. The pressure adjusting shaft is arranged on the top of the needle shaft and is coupled to the inner surface of the valve body. The first pipeline is formed in the valve body. The second pipeline is formed in the needle shaft. The third pipeline is formed from the top to bottom of the needle shaft and is connected to a groove(32) of the needle shaft. The elastic member is formed between the valve body and the needle shaft.