Fuel injection pump for IC-engine - has spring-loaded pistons which delay start of main fuel flow to injection nozzle

摘要

The fuel injection pump for an ic-engine has a piston (2) which operates in a cylinder which is supplied with fuel through ports (4a, 4b) which connect the cylinder to an annular chamber (5) which receives fuel from the main pump. As the piston moves upwards the increasing pressure of the fuel acts on the primary injection piston which pumps fuel to the injection nozzle through the passageway (13).When this primary piston (11) abuts against the stop (12) the fuel pressure acts on the delay piston (19) through the passageway (17) and compresses the spring (22) so that the main supply of fuel flows out through the non-return valve (26).