Fuel injector including an outer valve needle, and inner valve needle slidable within a bore formed in the outer valve needle

摘要

A fuel injector comprises an outer valve needle, an inner valve needle slidable within a bore formed in the outer valve needle, an inner end of the inner valve needle being located within the bore, the inner end of the inner valve needle being provided with a recess whereby the application of fuel under pressure to the bore deforms the inner valve needle to form a substantially fluid tight seal between the inner and outer valve needles. The inner and outer needles may be exposed to the fuel pressure within a common control chamber, a single actuator arrangement being used to control movement of both needles.