Abstract：To investigate the coupling effects of unit additional lift duration angle and unit additional lift peak value with the original valve type line peak interval angle on the gas path state parameters, the DK4A diesel engine was taken as the research object, and the different valve type lines were introduced to simulate under the engine speed of 2 800 km·h-1 and 50% load condition.The effects of unit additional lift duration angle, additional lift peak value and original valve profile peak interval angle on the weight of gas path state parameters were analyzed and discussed. The results show that the interval angle between the unit additional lift peak value and the original valve profile peak value is from 100° to 140°, and the additional lift duration angle is from 92° to 132°.The increases of the additional lift peak value and the original valve profile peak interval angle are beneficial to the increase of the influence weight on the air path state parameters, and the influence weights of the unit additional lift peak value and the original valve profile peak interval angle on the change rate of air inlet state parameters are greater than that of the unit additional lift duration angle.
