Research And Developing On Fuel Injection Pump With Top Clearance Plunger

Series of study and developing on Fuel Injection System (FIS) with Top Clearance Plunger (TCP) were presented in this paper. On the basis of systematic comprehension and analysis on mechanism of the Start of Injection (SOI) advancing automatically and application in different apparatuses, and according to running characteristics of in-line pump and structure specialization of TCP, this paper has analyzed the mechanism of TCP by using the theory of hydraulic mechanics:Accurate calculations to flow area of spill ports and profound analysis to factors influencing flow resistance have been done, and then the profile of pressure in plunger chamber VS cam angle were worked out to explain how FIS advance the SOI with rising speed by using TCP in the pump. During the course of developing, firstly, according to engine requirements, design targets must be defined, including fueling, advanced angle and the other parameters. And then a system model was set up by using HYDSIM and combining with tests to simulate the whole FIS and define the optimized parameters of TCP and other components in pump. With all parameters having been optimized, a Design of Experiment (DOE) has been worked out on the sample pump to check whether the test results of pump performance achieve the beforehand design goals or not. From the results of matching test, a conclusion has been driven as that a FIS with TCP can meet the requirement of engine, including power, economic, and emission. While a FIS with TCP is taking the place of a FIS with an advancing apparatus, stabilization and consistency are becoming two key factors which confine its further development. By analyzing how the different parameters in FIS influence consistency of the SOI advance, all factors have been found out. On the foundation of research and analysis over the main factors, this paper pointed out some suggestion to solve problems above all.