Research On Electromagnet And Drive Technology Of Sub-millisecond High-speed Switch Valve For Vehicles

With the high performance demand of transmission and braking system for engineering vehicles,the development of electro-hydraulic shifting technology has received wide attention in the industry.As a core component in the electro-hydraulic shifting system of the new generation of engineering vehicles,the high-speed on-off valve can be directly connected to the computer interface,and has strong anti-pollution capability.The cost is only about 1/10 of the servo valve and proportional valve.At present,the high-speed on-off valve products in China are poor,and their dynamic response time is several milliseconds.There are few research papers on sub-millisecond high-speed on-off valves.In this paper,the design,theoretical analysis,simulation optimization and experimental research on the internal electromagnet,valve body and drive technology of the high-speed on-off valve for vehicles are carried out,and the response time of the valve is shortened to sub-millisecond.First of all,combined with the working environment and indicators,the basic structure of the high-speed switching valve is determined.Based on the electromagnet design theory,and taking into account the "knee point" method,structural factor,working system and temperature rise,the theoretical calculation and verification of the electromagnet structure parameters are carried out.The critical structural dimensions and dynamics analysis of the valve body are carried out.Considering the coupling relationship between the electromagnet and the valve body,the circuit segmentation method is used to obtain the relationship between the circuit link,the magnetic circuit link and the motion link.Based on MATLAB/Simulink and AMESim software,the theoretical model of highspeed on-off valve is built,and the dynamic characteristics are obtained without considering the magnetization process and eddy current.Secondly,a static magnetic field model based on ANSYS Electronics is established for high-speed switching valve electromagnets.Considering the factors such as the magnetic isolation ring,the position and angle of the magnetic isolation ring and other factors,the structural parameters and working parameters of the electromagnet are analyzed based on the purpose of improving the electromagnetic attraction characteristics.The electromagnetic attraction of the initial air gap position is increased by 2 times.Then the dynamic magnetic field model based on ANSYS Electronics is established,and the structural parameters and working parameters of the electromagnet are analyzed based on the purpose of shortening the response time.Considering the relationship between coil current density and temperature rise,the influence of the inductance and resistance change of the parallel coil on the dynamic characteristics of the electromagnet is analyzed based on the electrical time constant.In view of the phenomenon that the magnetization in the transient magnetic field of the electromagnet is concentrated on the surface layer,the magnetization is uneven and the iron loss is large,the eddy current effect is effectively reduced by using the new soft magnetic composite material Somaloy 700 HR 5P and the design of the cylindrical laminated structure electromagnet.Then,the dynamic characteristics and static characteristics of the high-speed on-off valve under dual-voltage drive control are analyzed.The influence of valve body structure parameters on the response time of high-speed on-off valve is discussed.It is optimized based on genetic algorithm.Based on this,a capacitor energy storage variable voltage control strategy is proposed.The voltage characteristics of the variable inductance RLC circuit with different damping degrees are discussed.The effects of capacitance capacity and discharge time on the dynamic response of high-speed switching valves are analyzed.The feasibility of continuous operation of capacitors under this strategy is verified.Finally,the sub-millisecond response speed target is achieved and the final high-speed on-off valve model is obtained.Finally,a high-speed on-off valve electromagnet test bench was built to design and process the electromagnet principle test piece,and the theoretical analysis and simulation were comprehensively verified through experiments.This paper provides an idea for the development of digital valves in the direction of high response.