再制造发动机磨合质量振动监测的测点位置选择

Measuring Position Selection of Running-in Quality Vibration Monitoring for Remanufactured Engine

利用振动信号监测再制造发动机磨合质量,测点的准确选择对于获取有效信号,降低信号处理难度至关重要。在分析发动机各激振源特性及振动传播途径的基础上,以康明斯6BT 5.9再制造发动机为对象,采集发动机缸盖、缸盖之间缸体、活塞上止点对应的缸体端面等处的振动信号,采用时域分析、时频分析、小波包分解子带能量等方法对磨合过程中采集的样本信号进行分析及特征提取。结果表明,在发动机缸盖、活塞上止点对应的缸壁、活塞上止点对应的缸体端面处采集的信号,能够获得反映磨合质量变化的振动信息,其中,缸盖位置获取的振动信息最敏感,在选择测点位置时应该优先考虑。

Accurate selection of measuring points is essential for obtaining effective signal and reducing signal processing difficulty while monitoring running-in quality of remanufactured engine with vibration signal. After analyzing the characteristics of excitation sources and vibration transmission route, the paper takes Cummins 6BTS. 9 type remanufactured engine as the object and collects vibration signals from cylinder head, cylinder and cylinder section, and analyzes and extracts features of sample signals with time-domain analysis, time-frequency analysis and wavelet packet decomposition sub-band energy method. The result shows that all these signals can obtain vibration information that reflects the change of running-in quality, and the vibration information from cylinder head is most sensitive, which should be taken priority while selecting measuring position.