Common rail fuel injector for use in internal combustion engine, has check needle including opening hydraulic surface exposed to fluid pressure of nozzle supply passage and closing hydraulic surface exposed to fluid pressure of chamber

摘要

The fuel injector (12) has a check speed control device (74) fixedly positioned within a check control chamber (70) of an injector body (34). A control valve assembly (88) comprises a valve (98) i.e. flat ball valve, transferring fluid from an upper bowl of the control device and a check control line of the injector body to a low pressure drain (90). A check needle (46) includes an opening hydraulic surface (102) exposed to fluid pressure of a fuel supply passage (43) and a closing hydraulic surface (60) exposed to fluid pressure of the control chamber. Independent claims are also included for the following: (1) a method for controlling closing speed of a check needle during an injection event (2) an internal combustion engine comprising an engine housing.