High Quality Delivery Valve F167 Diesel Engine Spare Parts

The delivery valve, a key control component in high-pressure fuel systems, ensures timely and quantitative injection from the injector through precise shutoff and pressure maintenance. Its performance directly impacts engine combustion efficiency and emissions. This article explains the structure, function, failure mechanisms, and technological innovations of the delivery valve, providing a reference for optimizing high-pressure common rail systems.

I. Structure, Function, and Operating Principle

A typical delivery valve consists of a sealing cone, a pressure relief ring, a return spring, and a guide. Its core function is bidirectional control: During fueling, the valve cone opens under a high pressure of 220 MPa, allowing fuel to enter the high-pressure fuel line through a φ3-5 mm flow hole. During fueling, the pressure relief ring (with a clearance of 0.002-0.005 mm) first shuts off the fuel flow, stabilizing the residual pressure in the line at 10-15 MPa and preventing injector leakage. The split-body design improves fueling efficiency by 15%, meeting Euro III and higher emission standards.

II. Failure Mechanisms and Prevention Technologies

Cavitation and wear are the primary failure modes: the bubble burst pressure at the high-pressure sealing surface can reach 140 MPa, leading to microscopic pitting. When the wear of the pressure relief ring exceeds 0.01 mm due to fuel impurities, this can cause backflow in the high-pressure fuel pipe, resulting in fuel delivery deviations of up to 8%. Preventative measures include: using a BN-SiN composite ceramic thin film coating (thickness <3 μm) to improve wear resistance by 2-4 times; and optimizing the sealing surface groove structure to reduce the bubble burst pressure to below 10 MPa.

III. Technical Optimization and Development Trends

CFD simulation optimization revealed that increasing the connecting hole diameter to φ4 mm can shorten opening and closing times by 15%, and that the guide groove design can improve bubble distribution uniformity by 40%. Intelligent integration is emerging. The delivery valve with an integrated micro pressure sensor provides real-time feedback on pressure fluctuations, dynamically adjusting the spring preload in conjunction with the ECU to maintain injection accuracy within ±2%. In the future, the multi-channel coordinated control structure adapted to the 3000bar ultra-high pressure system will become a key technology for meeting the National VII emission standards.