FUEL INJECTORS FOR DIESEL ENGINES

摘要

A fuel injection for use in a diesel engine and adapted to inject two different fuels sequentially comprises a body including an injection nozzle (6) defining one or more injection orifices (6a), a main fuel supply passage (1) and a pilot fuel supply passage (8) which includes a first non-return valve (9) arranged to prevent fuel flowing in it away from the injection nozzle (6). The nozzle (6) is controlled by a valve needle (5) which affords a surface (5a) directed towards the injection orifice(s) (6a) and exposed to a fuel supply gallery (4). The body contains a cylinder (13) which slidably receives a piston (2). The main fuel passage (1) communicates with cylinder (13) adjacent one end thereof and the pilot fuel passage (8) communicates with the cylinder (13) adjacent the other end thereof and with a first outlet passage (10) which communicates with the fuel gallery (4) and includes a second non-return valve (11) arranged to prevent fuel flowing from the fuel gallery (4) into the pilot fuel passage. A second outlet passage (3) communicates with the fuel gallery (4) and with the cylinder (13) at a point intermediate its ends, whereby the main fuel passage (1) communicates with the fuel gallery (4) via the cylinder (13) and the second outlet passage (3) when the piston (2) is at the said other end of the cylinder (13) but not when it is at the said one end of the cylinder (13).