The Development Of Press Based On Gas And Liquid Pressurization

In the existing pressure loading station of automobile parts automatic assembly production line,gas-liquid presses adopt single-channel gas supply control mode,but there are many problems such as the high output press overshoot and low control precision,which can not meet the requirements of high precision pressing.Therefore,combined with the advantages of pneumatic and hydraulic presses,a gasliquid press machine equipped with multi channels is designed based on the gas-liquid pressurized technology,which is low overshoot,high control precision and can meet the requirements of high precision and high efficiency in automobile parts pressing.The main research contents are as follows:(1)According to the requirement of the press for pressing the automobile parts,the technical index of the gas-liquid press is put forward.Combined the pressurizing principle of gas-liquid pressurized cylinder,to complete the overall program,the mechanical structure of press and dual-channel,with two high-speed on-off valve pneumatic control system principle diagram are designed.(2)Based on the gas path control system principle diagram and the gas-liquid pressure cylinder mechanical structure,two pneumatic control system mathematical model of dual-channel and high speed on-off valve are established.Firstly,to get the cut-off pressure of auxiliary channel which is the switching pressure of dual-channel supply to single channel supply of the smaller aperture,the dual-channel air path control system is simulated,which can be used as a basis to design the switching pressure of dual-channel gas-liquid press machine in practical applications.With the cut-off pressure of auxiliary channel,the high-speed on-off valve pneumatic control system mode is simulated.In comparison with dual channel control system,highspeed on-off valve pneumatic control system overshoot smaller,but pressurization time longer,which can be theoretical support to improve control accuracy of gasliquid press.(3)Based on the software functional requirements of the gas-liquid press,the overall structure of the system software and the function of each module are designed.According to the different control modes,different flow charts are designed,then the modular programming is carried out,and the multi thread control technology is realized with the development environment of LabVIEW.(4)Combined with gas-liquid press overall scheme,the hardware of control system structure diagram is designed,gas-liquid press experiment platform is built and repetitive pressing experiment is done.The results showed that the experimental data is consistent with simulation data,which can be used in gas-liquid press actual pressing.To ensure that the gas-liquid press is stable and reliable,which can meet the design requirements,error sources and the uncertainty evaluation of the output pressure with dual-channel are analyzed.