흡기관 분사 방식 연료 레일의 압력 맥동 저감을 위한 연료 레일 형상 최적화

Fuel Line Hammer is defined as the audible noise heard in the vehicle passenger compartment resulting from fuel pressure pulsations in the fuel subsystem. The pressure pulsations are a result of injector-firing events and fuel line dynamics. The pressure pulsations consist of a multiple frequencies. Low frequency pulsations are the result of injector firing. High frequency pulsations are a result of line dynamics. Line dynamics are impacted by line diameter, length and stiffness of the fuel system components. Since the fuel feed line diameter and length are typically set by vehicle architecture, the stiffness (or compliance) of the fuel subsystem components is one of the few fuel system design variables available for effecting the pressure pulsations. Some kind of designs for fuel rails have been developed and introduced to reduce fuel pulsation for MPI (intake manifold port injection) system such as fuel rails with external damper or internal damper or integrated damping effect (called as self-damped fuel rail) in accordance with engine room design and noise requirements. Fuel rails integrated with internal dampers are introduced to reduce fuel pulsation effectively now a days instead of self-damped fuel rails even though they lead cost increase significantly. However some papers have introduced that the fuel rails with integrated damping effect (self-damped fuel rail) can reduce fuel pulsation effectively. This study focused on finding key parameter on fuel rail design with integrated damping effect to reduce fuel pulsation experimentally. It was found that the shape and volume are key factor to reduce fuel pulsation and the shape of fuel rail is more effective than the volume of fuel rail. : Static response, minimum the best, was characterized as parameter design.