Design And Research On Pneumatic High Speed On-off Valve Based On Giant Magnetostrictive Material

The proportional control of pneumatic high speed on-off valve can be realized under PWM mode, which can reduce the costs of servo control by substituting the pneumatic proportional servo valve. Giant magnetostrictive material (GMM), a new kind of functional material, has many advantages, such as rapid response, large force output, low magnetic field intensity demand, etc. These can improve the frequency response of valve radically. In this paper, the GMM has been used in pneumatic high speed on-off valve for the first time, and a new structural design has been presented. According to the structure, performance characteristic of the valve has been researched for details. The main content of the paper is summarized as follows:First, in this paper, beyond analyzing the problem in current pneumatic high speed on-off valve and discussing the characteristic of GMM, a new structure of pneumatic high speed on-off valve based on GMM has been presented.Second, the structural design of the valve has been researched and analyzed, which includes coil design, temperature simulation and thermal compensation design, magnetic circuit design and electromagnetic simulation, mechanism design of pre-pressure and displacement amplifier. All of the work has solved the main problem of the structural design and also make a foundation of the high-performance pneumatic high speed on-off valve.Third, according to the designed structure of the valve, a dynamic model of the valve based on electric-mechanical transfer model of giant magnetostrictive, material mechanics and mechanical vibration has been developed. According to the design parameter, a series of simulations based on the model has been performed to analyze the performance of the valve. These make an important theoretical support for the valve.Forth, some experimental systems have been established for experimental research of the steady state and dynamic state. The experiments include the steady flow characteristics, the degree of the valve opening and dynamic response. The results of the experiments show that the amplitude of the valve opening in 700Hz is 74.5% of that in low frequency. If the valve opening reaches over 60μm, the stiffness of the flow characteristic is better, and at this time, if the upstream pressure is set to 6bar, the maximum flow at least may reach 80L/min. The results also have been analyzed to direct the further improvement.