Design And Test Of Pneumatic Quick Switch Valve

With the high speed of economic development, the switch valve has gradually drawn people’s attention. However, there are mainly several pneumatic component manufactures studying the high speed pneumatic switch valve in the world.In our country, there is few study on the high-speed pneumatic switch valve, and the study is discontinuous. Compared with the international advanced technology, the difference is still large.This paper designs the pneumatic fast switch valve with a bidirectional impact cylinder as the actuator, and conducts analog simulations and experiment tests, the main work of which is as follows:(1) The structural design of the pneumatic fast switch flap valve.It mainly includes: the overall structural design of the two-way impact cylinder, and a detailed design and calculation of the key parts such as piston rod, buffer throttle, end cap, valve disc, cylinder, cover, etc; selection and calculation of butterfly valve;the design of a device which connects a bidirectional air cylinder with a butterfly valve. A new type of air-operated high-speed on-off butterfly valve is obtained.(2) We adopt the AMESim software to analyze the functions of the three-position five-path reversing valve and mainly study the effects of the parameters on the functions of valves when valve element moves in the valve clack under different air source pressure.The study shows: the response time of the valve which is 26 ms doesn’t change with the change of air source pressure; from the beginning of motion to the maximum value of enthalpy flux, the valve element costs roughly equal time in the different air source pressure, which is about 10 ms.(3) The valve shaft, the speed of the piston rod, the displacement and other change situations in the opening and closing process of the valve are obtained through the dynamical simulation of the opening and closing process of the pneumatic high-speed on-off valve with the combination of the software of ADAMS, and the analogue simulation of the pneumatic buffer device with the combination of the software of LMS Imagine.Lab AMESim.The results show that: the two-way impact cylinder at the 0.7Mpa gas source pressure, the switch valve opens and closes quickly, the time that the valve opening and closing require are close to each other, about 0.038s;Installing the pneumatic buffer device at the front end of the piston rod of buffer with a distance of 20.5mm from the left vertex of the power conversion device can effectively avoid hitting the valve seat by the valve plate.(4) A testing platform of the bidirectional impact cylinder was produced, which measured the changes of the piston rod speed, the maximum impact kinetic energy and the return kinetic energy under different gas source pressure, and the relationship between the gas source pressure and the return time under the circumstances that the piston rod was heavily loaded.The experimental result shows that the best working operation of the two-way impact pneumatic cylinder is 60 ~ 90mm; the return kinetic energy is 4%-80% lower than the impact kinetic energy; under the condition of heavy load, the return time of the piston rod decreases by about 10% once the bleed pressure increases by 0.1 bar.