High Quality Delivery Valve FZ5BQ Diesel Engine Spare Parts

Abstract:

The motion behavior of the delivery valve in a fuel injection pump plays a decisive role in determining the propagation characteristics of pressure waves within the high-pressure fuel line. Variations in valve motion dynamics directly affect injection pressure stability, fuel quantity accuracy, and the overall performance of the injection system. To clarify this mechanism, this study conducts a comprehensive mechanism analysis of pressure wave propagation influenced by delivery valve motion using both numerical simulation and experimental validation.

A dynamic model of the fuel injection pump was established, incorporating the valve lift profile, spring stiffness, mass–damping characteristics, and fuel compressibility. The coupled fluid–mechanical system was solved using a one-dimensional transient flow model combined with finite element analysis (FEA) to describe pressure oscillations in the fuel line. The relationship between valve motion and the resulting pressure waveforms was analyzed under varying engine speeds (600–1800 rpm) and injection pressures (60–160 MPa).

Results show that the valve lift speed and closing delay significantly influence the amplitude and phase of the reflected pressure waves. A faster valve opening induces a sharp pressure rise and stronger forward propagation, while delayed closure leads to secondary pressure oscillations and increased energy loss. The analysis reveals a critical damping ratio (ζ ≈ 0.35) at which wave attenuation is minimized and system resonance is avoided. Furthermore, the presence of micro-leakage during valve seating generates local pressure pulses, which couple with the primary wave to distort the pressure profile in the high-pressure line.

Experimental verification using a high-speed pressure transducer confirmed the simulation results, showing that optimizing valve spring stiffness and lift curve smoothness can reduce peak-to-peak pressure fluctuation by up to 18%.

The study elucidates the coupling mechanism between valve motion and pressure wave dynamics, providing theoretical guidance for the design of low-pulsation, high-response fuel injection pumps. The findings offer valuable insights for the development of next-generation high-pressure injection systems with improved stability, durability, and injection accuracy.