1、 How to find out, focus on finding hydraulic faults according to the hydraulic system diagram. When analyzing and troubleshooting the hydraulic system diagram, the main method is to "grasp both ends" - that is, grasp the power source (oil pump) and actuator (cylinder and motor), and then "connect the middle", that is, the pipeline and control elements from the power source to the actuator. When "grasping both ends", analyze whether the fault lies in the oil pump, cylinder and motor itself. When "connecting the middle", in addition to analyzing whether the fault is caused by the hydraulic components on the connected line, pay special attention to find out which control mode is adopted when the system is transferred from one working state to another and whether the control signal is wrong. Check one by one according to the real object, and pay attention to whether there is mutual interference between each main oil circuit and between the main oil circuit and the control oil circuit. If there is mutual interference, Analyze how to use adjustment errors, etc.
2、 Use cause and effect diagram to find hydraulic fault
Using the cause and effect diagram (also known as fishbone diagram) analysis method to analyze the faults of hydraulic equipment can not only quickly find out the primary and secondary causes of faults, but also accumulate the experience of troubleshooting.
Cause and effect diagram analysis can be used to closely combine maintenance management with fault finding, so it is widely used.
3、 Ferrography technology is used to diagnose and monitor the faults of hydraulic system
Ferrography technology takes the wear of mechanical friction pair as the basic starting point. With the help of Ferrograph, the wear particles and other pollution particles in hydraulic oil are separated and made into Ferrograph, which is then observed under Ferrograph microscope or scanning electron microscope, or deposited in glass tube according to size, and then quantitatively detected by optical method. Through the above analysis, we can accurately obtain important information about wear in the system. Therefore, further study the wear phenomenon, monitor the wear state, diagnose the fault precursor, and finally make the system failure prediction.
Ferrography technology can be effectively applied to the detection and monitoring of oil pollution degree, wear process analysis and fault diagnosis of hydraulic system of construction machinery, and has the advantages of intuition, accuracy and more information. Therefore, he has become a powerful tool for fault diagnosis and analysis of mechanical engineering hydraulic system.
4、 Use the correlation analysis table of fault phenomenon and fault cause to find out the hydraulic fault
According to the working practice, the correlation table between fault phenomena and fault causes (or provided by the manufacturer) is summarized, which can be used for the search and treatment of general hydraulic faults.
5、 Use the self diagnosis function of the equipment to find the hydraulic fault
With the continuous development of electronic technology, at present, many large and medium-sized construction machinery adopt electronic computer control, through interface circuit and sensing technology, self diagnose their hydraulic system and display it on the fluorescent screen. Users and maintainers can troubleshoot according to the displayed fault content.
