0714 Development of Hydraulic Variable Valve Timing System : The 4th Report: Applications to Combustion Control of PCCI Engine

Abstract

Energy accumulated type variable valve timing (EAVVT) system; a new type of hydraulic variable valve timing system was applied to a single cylinder diesel engine as a control device for premixed charge compression ignition (PCCI) combustion. Numerical calculations based on an elementary chemical reaction model were conducted to analyze the effect of intake valve close timing on PCCI. Engine tests were conducted to confirm the numerical calculation. As a result, it was found that knocking limit expanded when center of combustion was delayed to after TDC by intake-valve-timing control, although favorable ignition timing range was narrow since misfire would occur.