Electro-Hydraulic Proportional Valve Drived By Moving-coil Bidirectional Electric Mechanical Converter

With the rapid development of electro-hydraulic proportional control technology,electro-hydraulic proportional valve is more and more widely used in engineering.Compared with electro-hydraulic servo valve,electro-hydraulic proportional valve has high anti-pollution capacity,can significantly improve the stability of the operating system,effectively reduce the barriers to work.And the cost is relatively low,electro-hydraulic proportional valve has no precise and sensitive parts and is more suitable for industrial engineering,but in terms of response its speed,control precision is still insufficient.In order to improve the dynamic and static characteristics of the electro-hydraulic proportional valve,This paper presents a new structure of electro-hydraulic proportional valve,its driving part adopt moving-coil type bidirectional electric mechanical converter.The innovation is the use of a single proportional solenoid to achieve bidirectional drive spool movement so as to improve the performance index of electro hydraulic proportional valve.the research on the electro-hydraulic proportional valve drive by moving-coil type bidirectional electric mechanical converter has a positive meaning for the study of new electro-hydraulic proportional valve.The main research work of this paper is as follows:1)Analysis of the structure,wiring and circuit of moving-coil type bidirectional electric mechanical converter,and the materials used of main parts were selected;2)Describes the slide valve function of valve spool and the structure of valve body,its working principle.And the valve body and valve spool are selected;3)According to the requirements of the alignment and zero adjustment of the electro-hydraulic proportional valve,the zero adjustment device is designed,at the same time according to the requirements of the spring to determine its specific parameters;4)The sealing structures and methods of the electro-hydraulic proportional valve were designed.According to the international standard,the material and size parameters of the O rings were determined;5)Some parts with higher machining precision are described in detail to ensure the dimensional accuracy,shape precision and quality of fit;6)Analysis and design the connection mode of moving-coil type bidirectional electric mechanical converter and spool;7)Analysis and study the F-i,F-s characteristics of moving-coil type bidirectional electric mechanical converter,spool force and the flow rate of the electro-hydraulic proportional valve to obtain the relationship between output flow and input signal;8)Develop the prototype and describe in detail the problems needing attention in the assembly process of the prototype;9)To establish the hydraulic test system to test the prototype,according to the test results to analyse the defects of the prototype and propose the improvement method;10)Design A control method of independent superposition flutter signal,Re-establish the hydraulic test system to test the prototype,Collate experimental data and calculate the performance indexes such as hysteresis,dead zone and linearity.The results show that electro-hydraulic proportional valve drive by moving-coil type bidirectional electric mechanical converter basically satisfied the performance of the electro-hydraulic proportional directional valve,and can meet the engineering requirements,its static index mainly meet the standard.