摘要
采用集中质量法建立了某V12柴油机扭振动力学模型,计算得到了800~2500 r/min转速范围内的进排气左右凸轮轴负载扭矩激励,对凸轮轴进行了强迫振动仿真,获取凸轮轴各谐次扭转振幅和滚振谐次,并分析计算凸轮轴滚振振幅。结果表明:第4.5,5.0,5.5及6.5谐次主要贡献凸轮轴强迫扭振振幅,在2500 r/min转速区域时凸轮轴扭振振幅峰值均达到最大值,3谐次的激励力矩是构成滚振的主要成分。分析并获取试验柴油机凸轮轴滚振最佳简谐系数,采用多次近似拟合低转速下的振幅结果以消除滚振误差的方法,建立了凸轮轴滚振计算模型,滚振计算的振幅与扭振动力学模型3谐次简谐振幅在800~1900 r/min中低转速时幅值比较接近,差值小于0.02°,因滚振发生在较低转速,故滚振计算结果满足要求。该计算体系与研究结论为发动机凸轮轴系滚振的预测与控制提供了建议和参考。
The mechanical model of torsional vibration for a V12 diesel engine was established by the concentrated mass method,the calculation was conducted to acquire the load torque excitation of the left and right camshafts of intake and exhaust between 800 r/min and 2500 r/min,and the forced vibration simulation of camshaft was performed to obtain the torsional vibration amplitude and rolling vibration frequency of camshaft and further analyze the rolling vibration amplitude.The results showed that the 4.5th,5.0th,5.5th and 6.5th order mainly contributed to the camshaft forced torsional vibration amplitude.Their peaks reached the maximum at 2500 r/min and the 3rd order excitation torque constituted the main component of rolling vibration.The optimal harmonic coefficient of the camshaft rolling vibration was analyzed and obtained,the multiple approximate fittings of amplitude results at low speed were conducted to eliminate the rolling vibration error,and the rolling vibration calculation model of the camshaft was established.The calculated amplitude of rolling vibration was close to the 3rd harmonic amplitude of torsional vibration mechanical model between 800 r/min and 1900 r/min and the difference was less than 0.02 degree.The rolling vibration calculation results met the requirements because the rolling vibration occurred at low speed.Accordingly,the calculation and research conclusions provided the suggestion and reference for the prediction and control of engine camshaft rolling vibration.
作者
彭海雄
辛花
陈正虎
王小慧
熊毕伟
兰银在
阎玮
王晓滕
PENG Haixiong;XIN Hua;CHEN Zhenghu;WANG Xiaohui;XIONG Biwei;LAN Yinzai;YAN Wei;WANG Xiaoteng(China North Engine Research Institute(Tianjin),Tianjin 300400,China;The Third Military Representative Offices in Shijiazhuang,Shijiazhuang 050000,China)
出处
《车用发动机》
北大核心
2021年第4期79-85,共7页
Vehicle Engine
关键词
柴油机
多体动力学
凸轮轴
扭振
滚振
diesel engine
multi-body dynamics
camshaft
torsional vibration
rolling vibration
