可变气门正时标定在气门正时设计中的作用

Effect of Variable Valve Timing Calibration on Valve Timing Design

以一款2. 0 L增压直喷双可变气门正时(VVT)汽油机为研究对象,在一定的工况区域进行发动机台架试验,标定VVT。试验结果表明,41%工况的进气VVT处于极限开启位置,将进气开启定时再提前,可以进一步降低燃油耗。为此,对进气气门正时进行错齿改造并试验,验证新增的进气VVT角度可以使发动机获得更好的经济性表现。试验结果表明,错齿改造使发动机燃油耗降低,说明VVT的标定结果可以对气门正时设计提出改进意见。

The calibration of the variable valve timing (VVT) of a 2.0 L turbocharged gasoline direct injection engine was carried out at certain operating conditions on engine test bench. The test result shows that the intake VVT reaches its Maximum opening position at 41% operating conditions, and the further advance of intake valve timing benefits fuel reduction. Then, the advance of intake valve was made by misaligning gear teeth and the verification was conducted. The results show that the expansion of intake VVT angle can make the engine achieve better economic performance, indicating that the result of VVT calibration can provide suggestion for improving valve timing design.