Monitoring method of hydraulic cylinder dynamic seal failure state based on fiber grating sensing

Abstract

The invention relates to a fiber bragg grating sensing based hydraulic cylinder dynamic seal failure state monitoring method. According to the method, the dynamic seal failure state of hydraulic cylinders is monitored timely through an optical fiber sensing technology, that is, fiber bragg grating strain transducers are laid at the bottoms and sides of hydraulic cylinder piston rod and piston dynamic seals, and a fiber bragg grating temperature transducer is lain in the hydraulic cylinder piston rod to monitor the dynamic seal state changes in the hydraulic cylinder timely. Strain and temperature change data of the hydraulic cylinder dynamic seal working surface are acquired and analyzed in real time through a hydraulic cylinder dynamic seal failure state monitoring system, and the hydraulic cylinder dynamic seal failure state is determined accurately through the comparison of the actual strain value and the standard value of the dynamic seal working surface of the hydraulic cylinder. The method has the advantages of being capable of achieving point measuring and multi-point distributive monitoring when the dynamic seal state changes are monitored during the working of the hydraulic cylinder, good in sensitiveness, high in accuracy and capable of preventing leakage failures effectively and preventing environmental pollution.

Description

technical field [0001] The invention relates to the field of hydraulic cylinder dynamic seal failure state monitoring, in particular to a hydraulic cylinder dynamic seal state monitoring method based on optical fiber grating sensing. Background technique [0002] The hydraulic cylinder is the actuator in the hydraulic system and has an important influence on the performance of the hydraulic system. The sealing performance of the hydraulic cylinder is guaranteed by the sealing elements in it, and the sealing elements usually work in a medium environment with a certain pressure, especially the dynamic seal. During the reciprocating movement of the piston, due to the dynamic seal and the hydraulic cylinder The friction between the inner walls of the cylinder, as well as the pollutant particles in the oil, etc., are the causes of fatigue, damage, torsion, swelling, extrusion into the gap and other failure forms of the dynamic seal. Among all kinds of failures of hydraulic cylin...

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Problems solved by technology

[0003] At present, the monitoring methods for the failure state of hydraulic cylinder seals can be mainly divided into two categories, among which: the first method is mainly to observe the extension end of the piston rod of the hydraulic cylinder by the operator, and judge whether there is any leakage of the liquid medium. Whether the sealing state is normal; the problem with this type of method is that it is difficult to find out in time through observation in the early stage of seal failure, and when the leakage of liquid medium is found through observation, the seal inside the hydraulic cylinder is already in a serious failure state Therefore, it is impossible to avoid the impact on the operation efficiency of the whole machine equipment due to the failure of the seal, as well as the pollution and harm to the environment

However, the second type of method is usually offline analysis, and requires the accuracy of the collected pressure signal to be very high. If there are interference factors in the collection process, it will have a great impact on the analysis results

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