内燃机缸盖振动信号建模与仿真

针对现有内燃机振动信号采集方法存在的问题,提出一种通过建模仿真来模拟内燃机不同工况振动信号的方法。首先,建立内燃机配气机构动力学模型及气缸模型,分别用来模拟不同间隙气门的落座力及气缸压力;其次对内燃机缸盖进行模态分析,提取前30阶振型及其对应的频率;最后采用有限元法建立内燃机缸盖模型,借助气门落座力及气缸压力仿真结果对缸盖振动进行模拟仿真。利用缸盖振动的实测信号对其模拟信号进行验证,结果证明模拟方法有效可行。

Modeling and simulation of cylinder head vibration signal of internal combustion engine

In view of the problem with the existing methods for vibration signal acquisition of the internal combustion engine,a method for simulating internal combustion engine vibration signals under different conditions by modeling and simulation was proposed. Firstly, a dynamic model of the valve train of the internal combustion engine and a cylinder model were established to simulate the valve seating force of different valve clearances and the cylinder pressure, respectively. Secondly, the modal analysis of the cylinder head of the internal combustion engine was carried out,and the top 30-order vibration modes and their corresponding frequencies were extracted. Lastly, the cylinder head model of the internal combustion engine was established by finite method,and the valve seating force and the cylinder pressure obtained by simulation were used to simulate the cylinder head vibration. The simulated vibration signal was verified by the measured cylinder head vibration signal,and the results proved the effectiveness of the simulation method.