Calculation of Needle Valve Seating Stress for Fuel
Injector of Diesel Engine
Yao Chunde
(Tianjin University, Tianjin, 300072)

Abstract: This paper presented a formula which is derived from the theory of strain wave, to calculate the seating stress for the low-mass fuel injector without push-rod. It was illustrated that the calculating results by the formula well tallied with those in practice. It illustrated that the calculating results by the formula well tallied with those in practic. Therefore the formula could be taken as a trustybasis to design a nozzle and to select the needle valve opening pressure for the fuel injector without pust-rod. Meanwhile, the new formula presented in this paper also solves the contradiction which the needle valve opening pressure used in practice is not accordance with the one calculated from the old formula.
Keywrods: seating stress, injector of diesel engine, strain wave.