Conversion of jerk type injector to accumulator type injector

摘要

A standard jerk type fuel injector can be converted to an accumulator type fuel injector by modifying internal flow configurations of the injector from ones which lead to injection whenever fluid pressure in a fuel supply passage thereof exceeds a first designated level to ones which present an accumulator and a control cavity and which lead (1) to injector charging when the fluid pressure in the supply passage exceeds a second designated level and (2) to initiation of injection only upon subsequent pressure decay in the supply passage below a third designated level. The conversion can advantageously be performed by replacing a first spacer having a first set of flow configurations with a second spacer having a second set of flow configurations including a non-return element. The resulting injector has (1) an accumulator volume located fluidically downstream of the non-return element and (2) a control cavity above the nozzle needle. The accumulator type injector can be retrofitted into an existing injection system on site or assembled as a new construction by using primarily stock jerk type injector components. Manufacturing expenses can thus be sharply reduced, thereby promoting retrofitting, low volume production, and/or standardization.