1. How to find, focus on finding hydraulic faults according to hydraulic system diagram. When analyzing and eliminating the fault in hydraulic system diagram, the main method is to "grasp both ends"
-That is, grasp the power source (oil pump) and the actuator (cylinder, motor), and then "connect the middle", that is, the pipeline and control element passing from the power source to the actuator. When "grabbing both ends", it is necessary to analyze whether the fault lies in the oil pump, cylinder and motor itself. "In the middle", besides paying attention to analysis,
Whether the obstacle is outside the hydraulic components on the connected road, pay special attention to figure out which control method is adopted when the system is transferred from one working state to another working state, and whether the control signal is wrong. Pay attention to whether there is a connection error between each main oil circuit and between the main oil circuit and the control oil circuit to cause mutual interference. If there is mutual interference, it is necessary to analyze how the adjustment error is used.
Second, use the cause and effect diagram to find hydraulic faults
Using the causality diagram (also known as fishbone diagram) analysis method to analyze the failure of hydraulic equipment, not only can quickly find out the main cause of the failure, but also accumulate experience in troubleshooting.
Causality diagram analysis method can be used to closely combine maintenance management and fault finding, so it is widely used.
3. Apply Ferrography to diagnose and monitor the failure of hydraulic system
Ferrography technology is based on the wear of mechanical friction pairs. The wear particles and other contaminated particles in hydraulic oil are separated with the help of a ferrite spectrometer to make a ferrite sheet, which is then placed in a ferrite microscope or scanning electron microscope. Observation is carried out under the following conditions, or deposited in the glass tube in order according to the size, and the optical method is used for quantitative detection. Through the above analysis, you can accurately obtain important information about wear in the system. According to this, further study the phenomenon of wear, monitor the state of wear, diagnose the precursors of failure, and finally make a system failure prediction.
Ferrography technology can be effectively applied to the detection, monitoring, analysis of wear process and fault diagnosis of hydraulic pollution of construction machinery hydraulic system, and has the advantages of intuitive, accurate, and more information. Therefore, he has become a powerful tool for diagnosis and analysis of mechanical engineering hydraulic system failures.
Fourth, use the fault phenomenon and fault cause correlation analysis table to find hydraulic faults
According to the work practice, summarize the correlation table between the fault phenomenon and the cause of the fault (or provided by the manufacturer), which can be used to find and deal with general hydraulic faults.
Fifth, use the device's self-diagnosis function to find hydraulic faults
With the continuous development of electronic technology, at present, many large and medium-sized construction machinery adopt electronic computer control, self-diagnosis of their hydraulic systems through interface circuits and sensor technology, and display it on the fluorescent screen. Display the content of the fault for troubleshooting.
