某柴油机DPM出油管振动分析及优化

董福祥^1,2,丁保安^1,2,李秀山^1,2,张新众^1,2,王晓波^1,2,郭鑫^1,2

1.内燃机可靠性国家重点实验室，山东 潍坊  261061； 2.潍柴动力股份有限公司，山东 潍坊  261061

摘要：针对某六缸柴油机颗粒物消除系统（de-particular matter，DPM）出油管裂纹漏油的问题，利用有限元软件对原出油管进行模态分析，采用仿真和振动试验分析DPM油管裂纹漏油原因并进行结构优化，对优化后的DPM油管在发动机台架上进行振动试验验证。仿真计算及试验结果表明：出油管出现裂纹导致漏油的原因是出油管的一阶模态频率较低，发动机激励与出油管模态耦合，引起共振导致油管剧烈振动；更改出油管的结构、加强油管约束、提高出油管系统刚度，使出油管的一阶模态由86 Hz提升到166 Hz，有效避免了发动机激励与出油管模态频率耦合引起的共振，DPM出油管的振动强度降低，解决了出油管裂纹导致的漏油问题。该方法可以为提高油管运行可靠性提供参考。

关键词：DPM；油管；振动试验；有限元仿真

Vibration analysis and optimization of DPM tubing for a diesel engine

DONG Fuxiang1,2，DING Baoan1,2，LI Xiushan1,2，ZHANG Xinzhong1,2，

WANG Xiaobo1,2，GUO Xin1,2

1. State Key Laboratory of Engine Reliability, Weifang 261061,China； 2.Weichai Power Co., Ltd., Weifang 261061,China

Abstract：Aiming at the problem of crack and oil leakage of outlet pipe of De-particular Matter (DPM) of a six cylinder diesel engine,finite element software is used to carry out modal analysis of the original state of the outlet pipe, and the DPM pipe is optimized by combining simulation and vibration test. The optimized structure is verified by vibration test on engine bench. Simulation calculation and test results show that the natural frequency of the outlet pipe in the original state is low, and the coupling of the engine excitation and the outlet pipe mode leads to the vibration of the pipe, which is the reason for the crack and oil leakage of the outlet pipe. The structure of the outlet pipe is modified and the constraints of the outlet pipe is strengthen to improve the stiffness of the outlet pipe system. The first-order mode of the outlet pipe is increased from 86 Hz to 166 Hz, effectively avoiding the excitation of the engine rotation frequency, and the vibration performance of the DPM outlet pipe is significantly improved and the vibration intensity is reduced.This method can provide reference for improving the reliability of the operation of the outlet pipe.

Keywords: DPM; tubing; vibration test; finite element simulation