某装载机消声器支架模态分析与改进

许震^1,2，段良坤^1,2，孙志明^1,2，辛承祖^1,2，曾超^1,2，范焕成^1,2

1.内燃机与动力系统全国重点实验室,山东 潍坊  261061；2.潍柴动力股份有限公司,山东 潍坊  261061

摘要：针对某装载机发动机消声器系统排气接管断裂漏烟问题，利用锤击法进行模态试验，试验数据与有限元仿真计算结果对比表明：系统1阶、2阶模态频率仿真与试验结果相对偏差均较小，模态振型均一致，消声器系统1阶模态频率较低，共振风险较高，容易造成零部件断裂。通过对比模态振型，确定在消声器与缸盖连接支架上增设加强筋，改进消声器本体支架外形结构的方案，并进行仿真对比分析。结果表明：该装载机消声器连接支架只增加加强筋，系统模态频率的变化较小；连接支架增设加强筋并改进消声器本体支架外形结构，可提高系统1阶、2阶模态频率，降低消声器系统共振风险，解决排气接管断裂故障。

关键词：模态计算；消声器支架；有限元分析；结构改进

Modal analysis and improvement of a loader muffler support

XU Zhen^1,2, DUAN Liangkun^1,2, SUN Zhiming^1,2, XIN Chengzu^1,2，

ZENG Chao^1,2, FAN Huancheng^1,2

1.State Key Laboratory of Engine and Powertrain System, Weifang 261061,China;

2. Weichai Power Co., Ltd., Weifang 261061,China

Abstract：In response to the problem of smoke leakage from the exhaust pipe of a loader engine muffler system, a modal test is conducted using the hammering method. The test data is compared with the finite element simulation results. The relative deviation between the first and second modal frequency of the system and the test results is small, and the modal vibration modes are consistent. The first modal frequency of the muffler system is low, with a high resonance risk, which could easily bring component breakage. By comparing the modal vibration modes, a reinforcing ribs on the connecting bracket between the muffler and the cylinder head is added to improve the external structure of the muffler body bracket, and simulation comparative analysis is also conducted. The results indicate that adding reinforcing ribs to the muffler connecting bracket of the loader shows a small impact on the modal frequency, while adding reinforcing ribs to the connecting bracket and improving the external structure of the muffler body bracket can increase the 1st and 2nd modal frequencies of the system, reduce the resonance risk of the muffler system, and solve the problem of exhaust pipe fracture.

Keywords:modal calculation; muffler bracket; finite element analysis; structural improvement