Theoretical Study on Tolerance of Fuel Injection System of Diesel Engine

It is known that the electronic-controlled fuel injection technique can bring better performance characters for diesel engines. So, more and more engines have been equipped with this new fuel injection system. The radial tolerance of precise fitting pieces in electronic-controlled high-pressure-common-rail fuel injection system of diesel engine will affect the performance and life of fuel injection system greatly. Now, the tolerance is usually chosen only by experience. In this paper, based on the fluid theory of laminar flow in slit flow way, the optimal formulas of radial tolerance for least sum of fluid leakage and viscous friction energy consumption have been established. Also a calculation example has been listed.