基于气缸压力和振动传递函数的缸体优化  

Optimization of Cylinder Block Based on Cylinder Pressure and its Vibration Transfer Function

作　　者：宋兆哲[1,2] 高锋军 宁志坚[1,2] 陈强 Song Zhaozhe;Gao Fengjun;Ning Zhijian;Chen Qiang(Great Wall Motor Company Limited,Baoding,Hebei,071000,China;Hebei Automobile Engineering Technology&Research Center)

机构地区：[1]长城汽车股份有限公司,河北保定071000 [2]河北省汽车工程技术研究中心

出　　处：《小型内燃机与车辆技术》2020年第2期59-64,共6页Small Internal Combustion Engine and Vehicle Technique

摘　　要：为了降低发动机缸体在曲轴作用下的振动,将燃烧激励用4次多项式进行标准化后施加到主轴承盖,用Polymax算法计算和识别模态试验中缸体的4000Hz以内振动振型和阻尼建立有限元振动传递模型。施加3个方向的燃烧激振力,计算缸体表面32个点的振动加速度。通过计算得出,对于缸体振动影响最大的Y方向(从排气侧指向进气侧),其激振时,响应点的RMS值降低了2.45 dB。表明缸体结构优化后,缸体表面振动降低。在半消声室内测试进、排气侧噪声,试验结果为进、排气侧1 m噪声总声压级RMS值降低了2.60 dB(A),表明缸体结构优化后,由于缸体表面振动降低,进、排气侧的噪声降低。Combustion shock waves are transmitted from piston and crankshaft to cylinder block,of which vibration amplitude enlargement will cause noise radiation increase.In order to reduce the vibration of engine block,a finite element vibration transmission model is established to optimize cylinder block.The combustion excitation is standardized by the fourth polynomial and applied to main bearing caps of the crankshaft.The polymax algorithm is used to calculate and identify the vibration modes within range of 4000Hz and damping ratio in the modal test of cylinder block.The vibration acceleration RMS value of 32 points on the cylinder block surface is calculated in three directions.Compared with the origin,the surface vibration of the developed cylinder block decreases.The value of the cylinder block response points decreases by 2.45dB in the Y direction,which has the greatest influence on the vibration of the cylinder block.It can be concluded that after the cylinder block structural optimization,the surface RMS vibration of the cylinder block decreases.The inlet and exhaust side noise is tested in the semi-anechoic chamber,and the RMS value of the total sound pressure level of 1-meter noise on the inlet and exhaust side decreases by 2.60dB(A),which indicates that after the cylinder structure is optimized the noise decreases with the vibration decrease of the cylinder block surface.

关 键 词：模态 激振 噪声 表面振动 

分 类 号：TK421.6[动力工程及工程热物理—动力机械及工程]