Exhaust Muffler Structure Analysis And Improvement Of An Internal Combustion Forklift

This paper carries on study on the exhaust muffler structure analysis and improvement of an internal combustion forklift to reduce its exhaust noise. The main work and research is listed below:First, build a mathematical model of the exhaust muffler, Transmission Loss is used as the benchmark of the noise elimination of the exhaust muffler, and analyze the influence of structural parameters (length, diameter, perforation rate and its arrangement, etc.) on its Transmission Loss using the software MATLAB to get the main structure parameters which have the largest effect on Transmission Loss.Second, build the finite element model of the exhaust muffler, carry out FEM simulation researches on its Transmission Loss using the FEM software Virtual Lab, and make a performance evaluation to the noise elimination of the muffler, point out the frequency ranges where Transmission Loss does not meet the requirements of noise elimination.Third, test the muffler exhaust noise of the forklift under its working conditions and get its noise spectrum, give out the frequency ranges where the exhaust noise is too high, make sure which structure parameters are not good to the muffler Transmission Loss according to the exhaust noise spectrum and the transmission loss curve obtained from FEM simulation before, make structure improvement to the muffler, and make sure the improvement is effective by FEM simulation.At last, test the exhaust noise of the improved exhaust muffler, the test result shows that the exhaust noise of the internal combustion forklift is reduced by 3dB(A) by the structure improvement to the original exhaust muffler.