摘要
通过对GDI增压发动机进行DVVT扫点试验,研究了DVVT对GDI增压发动机外特性性能、部分负荷燃油经济性和怠速稳定性的影响。试验结果表明:对于试验发动机的凸轮轴型线而言,排气VVT的开启对发动机性能起到负面影响;外特性方面,中等转速工况采用较大的气门重叠角可提高体积效率;高转速采用较小的气门重叠角可提高充量系数;怠速和部分负荷工况下,较小的气门重叠角对改善发动机稳定性有一定帮助。
The DVVT experiments of different working conditions for GDI turbocharged engine were carried out and the influences of DVVT on external characteristic performance,part-load fuel economy and idle stability were researched.The results show that,for the mould line of test engine camshaft,the opening of exhaust VVT has a negative impact on engine performance.For the external characteristic,larger valve overlap angle can increase the volumetric efficiency at medium speed.At high speed,smaller valve overlap angle can increase the charge coefficient.At idle speed and part-load,smaller valve overlap angle is beneficial to improve the stability of engine.
出处
《车用发动机》
北大核心
2012年第2期66-69,共4页
Vehicle Engine
关键词
汽油机
缸内直喷
可变气门正时
气门重叠角
gasoline engine
in-cylinder direct injection
variable valve timing
valve overlap angle
