Research Of The Pilot Operated Relief Valve Based On MRF

Hydraulic valves are the core control components in hydraulic system, its perfor-mance will impact on the static and dynamic characteristics of actuating elements and hydraulic system. With the development of advanced technology, the request of the engineering application of hydraulic transmission to hydraulic element is getting higher and higher, the traditional pilot operated relief valve can't realize the intellectualized control, the manufacturing and installation precision of the components are much higher, and it is sensitive to oil pollution, so new techniques and methods should be proposed to solve the problems.Magnetorhelogical fluid (MRF) is a kind of intelligent materials, which have been widely used in machinery, automobiles, aviation, architecture, medical care and other fields for its peculiar magnetorhelogical effect (MRE) and being formed a kind of new technology——magnetorheological technology. This paper designs a kind of magnetorheological pilot operated relief valve with the magnetorheological mechanism of MRF to realize intelligent and automation control of hydraulic system.This paper has summarized the magnetorheological technology research situation, introduced magnetorheological fluid (MRF) composition, magnetorheological effect (MRE) mechanism, working pattern, performance and preparation methods, Proposed the key technologies problem of design process in the magnetorheological pilot operated relief, aim at the key problem. Meanwhile we have solved the problem by the choosing suitable material to reasonable aspects, the magnetic circuit design and structural design, analysed the magnetic field of magnetorheological pilot valve which had been design by finite element analysis software ANSYS. It suggests that the working gap designed in the core and valve core can increase magnetic field intensity; and we also have analysed the flow field of the main valve, which indicated that if the main valve core uses the ball head, the valve core hemipyramid angle is bigger than the valve seat and the exit uses the circular arc transition, the import and export differential pressures of the magnetorheological pilot overflow valve can be decreased, the possibility that the cavitation occurs can be reduce, and causes the liquid flow to back of the fire valve core to avoid the valve seat embarking the cavitation. Established the mathematical model of performance to meet the design requirement, The Matlab/Simulink software simulation has analysed the static and dynamic characteristic of the magnetorheological pilot operated relief valve verified the rationality of the structure design and showed performance of magnetorheological pilot operated relief valve meet the design requirement.