Research of Fuel Pressure Fluctuation Suppression in the High Pressure Common-rail Fuel Injection System

To eliminate the pressure fluctuation at the inlet of the injection, a new damping filter with damping and vessel to inhibit the pressure fluctuation is studied through experiment methods. Experiments are conducted to verify the filter's performance under the control strategy of multi-injection. whether under the pre-main injection mode or under the main-post mode, the pressure fluctuation amplitude is the minimum when the diameter of the damping hole is 0.4 mm, the amplitude of main injection fuel mass deviation can be reduced by 70% under pilot-main injection mode, and the amplitude of post injection fuel mass deviation can be reduced by 85% under main-post injection mode; when the vessel volume increased from 1720 mm³ to 28000 mm³, fuel mass deviation is 0.2 mg, when the vessel volume decreased from 1720 mm³ to 0 mm³, fuel mass deviation is 6.0 mg. The filter proposed by this research can be used to eliminate pressure fluctuation at the injector inlet and improve the stability of high pressure common rail system.