Actuator And Driving Circuit Design For Electrohy-draulic On/off Valve With Low Power And High-speed

As key components of electro-hydraulic control system,the electro-hydraulic on/off valve plays an important role in many fields,such as aerospace,national defense,deep-sea exploration,automotive,agricultural machinery,construction machinery,metallurgical industry and so on.The performances of the actuator determines the characteristics of the electro-hydraulic on/off valve.Therefore,how to improve the performances of actuator has become a research focus on electro-hydraulic on/off valve.In order to improve the steady-state and transient performances of actuator for electro-hydraulic on/off valve,a low power and high-speed dual performances target of actuator for electro-hydraulic on/off valve is systematically,deep researched based on theory analysis,finite element simulation and experimental research.The main contents of the study are as follows:From standpoints of the application background and research significance of electro-hydraulic on-off valve,the research status and development trend of low power and high-speed electro-hydraulic on-off valve both at home and abroad are analyzed and summarized.In order tomeet the requirements of electro-hydraulic on-off valves for the steady-state and transient performances of actuator,based on the analysis of the transient response process and energy conversion relation of electro-hydraulic on-off valve,the strategies to improve the performances of actuator are summarized from two aspects: reducing power consumption and improving response speed.Then a dual performances target strategy for low power and high-speed is proposed.Based on the typical plane disc electromagnet,a flange bidirectional drive disc electromagnet is proposed.The two dimensional static magnetic field simulation models of two electromagnets are established and their magnetic field distribution are analyzed.The influence of main structural parameters on flange bidirectional drive disc electromagnet's static characteristics is discussed by simulation,and multi-parameter variables analysis is carried out,then the specific structural parameters are determined,the prototype is developed.Through simulation analysis and experimental study,the performance parameters of flange bidirectional drive disc electromagnet are obtained and compared with plane bidirectional drive disc electromagnet.After that a circuit with double duty cycle pulse width modulation for low power and high-speed unidirectional drive electromagnet and a circuit with double duty cycle pulse width modulation for low power and high-speed bidirectional drive electromagnet are designed respectively.And theory analysis the double duty cycle pulse width modulation signal ofcircuit' output.The simulation models of two driving circuits are established,and the feasibility of driving circuit is verified by simulation analysis.The prototypes of driving circuit are developed,and the test system of driving circuit is built for experimental study.The mathematical model of actuator for electro-hydraulic on-off valve is established,and the multi-physical field simulation model of electromagnet and driving circuit is established in the electromagnetic field simulation software(Ansys Maxwell).The influence of main electrical parameters on the steady-state and transient performances of electromagnet are simulated and analyzed,then the prototype parameters of the driving circuit are determined.The testing system for the steady-state and transient characteristics of electromagnet is built,and the performances of electromagnet is studied experimentally.The results show that under the action of the circuit with double duty cycle pulse width modulation for low power and high-speed unidirectional drive electromagnet,the opening time,closing time,and the total steady-state power consumption of a solenoid are 10 ms,22ms and1.25 W respectively within a stroke of 2.5mm.The electromagnetic force and the initial force to power of the flange bidirectional drive disc electromagnet are above 58 N and 10.74N/W within a stroke of 1 mm when the rated current is 0.45A(5.4W).Under the action of the circuit with double duty cycle pulse width modulation for low power and high-speed bidirectional drive electromagnet,the suction time,release time,and the total steady-statepower consumption of the flange bidirectional drive disc electromagnet are22 ms,22ms and 2.41 W respectively.It is verified that the innovative design of the actuator's structure and driving circuit can obviously improve its steady-state and transient performances,which is better to meet the drive requirements of electro-hydraulic on/off valve.