发动机进、排气门是保证发动机工作性能可靠性、耐久性的重要零件,是专门对发动机充量交换过程的控制,其特性参数主要是三个:气门开启相位、气门开启持续角度(即气门保持升起持续的曲轴转角)和气门升程。这三个特性参数对发动机性能、油耗和排放有重要影响。通常将气门开启相位和气门开启持续角度称为气门正时。随着发动机负荷和转角的改变,这三个特性参数(特别是进气门开启相位和开启持续角度)的最佳选择是根本不同的。 在传统的发动机中,由于这二个特性参数在运行过程中不能改变。过去往 Engine intake and exhaust valve is to ensure the reliability of the engine performance, durability of the important parts, is dedicated to the engine charge exchange process control, the characteristics of the parameters are mainly three: valve open phase, the valve opening angle (ie, valve Keep rising crank angle) and valve lift. These three characteristic parameters have a significant impact on engine performance, fuel consumption and emissions. Valve opening phase and valve opening continuous angle are usually referred to as valve timing. With changes in engine load and angle, the best choice for these three characteristic parameters (especially intake valve opening phase and opening angle of continuation) is fundamentally different. In traditional engines, these two characteristic parameters can not be changed during operation. Past