Abstract: To reducing the engine ignition vibration of a vehicle, correlation analysis is conducted to research on the correlation between different impact factors and the ignition vibration of the seat rail, and it is found that the Y-direction vibration of the rear suspension had a strong correlation with the vibration of the seat rail, and its correlation coefficient is 0.92, meanwhile, the peak frequency of Y-direction vibration of the seat rail is distributed around 13.75 Hz. And the test results of the engine rigid modal test indicating that the mode frequency of the rigid modal rotating around the Z-axis is coupled with the ignition frequency, causing excessive Y-direction vibration of the rear mount. After reducing the Y-direction stiffness of the rear mount, the mode frequency avoided the ignition frequency, and the ignition vibration of the seat rail is reduced by 27.7%. The results show that correlation analysis method while conducted to reduce the engine ignition vibration, can be helpful to quickly locate the vibration source and improve the efficiency of noise, vibration, harshness (NVH) development.

Key words: correlation analysis; engine; ignition vibration; mounting system

摘要： 针对某乘用车发动机点火振动问题，通过相关分析的方法研究不同关联因素与座椅导 轨点火振动之间的相关性，发现后悬置 Y 向振动与座椅导轨振动具有强相关性，其相关系数 达 0.92，同时，座椅导轨 Y 向振动峰值频率分布在 13.75 Hz 附近，发动机刚体模态测试结果 表明，发动机绕 Z 轴旋转刚体模态频与点火频率耦合，导致后悬 Y 向振动过大。降低后悬置 Y 向刚度后，该模态频率避开点火频率，座椅导轨点火振动降低 27.7%。研究结果表明，将相 关分析方法运用在乘用车发动机点火振动问题中，有助于快速定位振动源，提升噪声、振动 与声振粗糙度（NVH）开发效率。

关键词: 相关分析；发动机；点火振动；悬置系统