The Design Of Diesel Engine Test Bench And Comprehensive Analytical Test System

With the rapid development of automobiles, the performance demand of internal combustion engine is increasing fast. Therefore, the engine development and performance optimization are paid attention to, with the help of various bench test and acquisition technologies. According to the current experimental conditions, we developed the cylinder pressure acquisition and processing system. With the pressure acquisition system and the current vibration acquisition system, experiment had been carried out to finish the acquisition and analysis of the cylinder pressure and vibration.The test bench is based on the engine YC2108, equipped with all kinds of measuring instruments, such as dynamometer, fuel comsumption, control cabinet, etc. all the measuring instruments control the engine and detect its running state.Lab VIEW, matching the data acquisition card produced by National Instruments, is used to write the acquisition program to realize the cylinder pressure collection and storage. The cylinder pressure processing system, also written by LabVIEW, is used to average multi-cycle data and smooth the curves. With comparison among different filters, Butterworth filter is the fittest for fairing pressure curves.The vibration acquisition system is based on DH5922 dynamic signal test and analysis system. Matlab is used to write the processing program, which includes removal of trends, smoothness of curves and filtering out interfering signals, to make the collecting vibration available.With the conditions above, experiment was carried out to measure the influence of different valve clearances on vibration signal, and the relationship between cylinder pressure and vibration signal under different working conditions, to estimate the cylinder combustion process with vibration signal. TDC signal calibrated the phase information of cylinder pressure and vibration.This experiment not only verified the feasibility of the acquisition test program, but also provided a reference for the analysis of the cylinder pressure and vibration in future, and provided a way to monitor the engine running state and finish fault diagnosis of complex problems.