1、 常州机电职业技术学院 毕业设计（论文） 作 者： 王盛 学 号： 31011136 系 部： 汽车工程系 专 业： 汽车检测与维修专业 题 目： 工程机械液压系统故障诊断与分析 指导者： 房亚 刘少华 评阅者： 2013 年 4 月 工程机械液压系统故障诊断与分析 摘 要 液压故障诊断是判断机械设备液压系统的运行状态是否正常，液压系统是否发生故障，确定液压设备发生故障的部位及产生故障的性质和原因。同时，液压系统是结构复杂且精密度高的机、电、液综合系统，系统具有机液耦合、时变性和非线性等特性。液压故障因故障点隐蔽、因果关系复杂、易受随机性因素影响、失效分布较分散，加大了故障诊断与检测的难度。
2、液压故障诊断是由现代机械设备及其元件的高度可靠性要求和需要迅速排除故障而提出的。在许多要害工业部门，已经逐渐发展机器状态 监视和控制技术，利用机器在运行过程中的二次效应来诊断机器的状态。二次效应，是指机器在运行中所出现的现象，如温升、噪声、振动、压力振摆、泄漏量、流量、润滑油状态、运动速度及各种性能指标。因此，深入研究这些现象，有助于逐步建立完善的诊断理论，发展完善的测试技术及实现预知维修，提高现代化维修技术水平，把定期维修改变为预知维修。这样，不仅可以节约大量的维修费用，减少许多不必要的维修时间，而且还可以大大增加机器设备的正常运行时间，大幅度地提高生产率，产生巨大的经济效益。 关键词： 工
3、程机械 液压故障 诊断方法 故障诊断 步骤 Hydraulic fault diagnosis is judge mechanical equipment of the hydraulic system running state is normal or not, whether the hydraulic system failure, determine the hydraulic equipment the failure of the parts and produce the nature and causes of the fault. At the same time, hyd
4、raulic system is complicated structure and high precision of machine, electricity, liquid comprehensive system, the system has the machine liquid coupling, changeable and nonlinear characteristics. Hydraulic failure due to a failure point concealment, causal relationships complex, vulnerable to rand
5、om factors affecting, failure distribution is more dispersed, increase the fault diagnosis and the difficulty of the test. Hydraulic fault diagnosis is by modern mechanical equipment and its components of high reliability requirements and need to quickly remove the faults and proposes. In many key i
6、ndustrial sector, has gradually development state monitor and control technology of machine, use of machines in operation process of the second-order effect to diagnose the state of the machine. The second-order effect, it is to point to in operation of machine in phenomena, such as temperature, noise, vibration, pressure vibration place, leakage, flow, lubricating oil state, velocity, and various performance indicators. Therefore, further study of these phenomena, help to gradually establish a perfect diagnosis theory, the development of
