Research And Application Of The Key Technologies On Green Precision And High Efficiency CNC Die-sinking EDM

To improve the efficiency and accuracy of environmental friendliness,three technical directions:high efficiency drive,precision molding and green machining are pointed.Key technologies,electrode precision compensation,counterweight disturbance rejection of the linear servo by compensation and green purification water-curtain hood,have been researched and applied in a integration platform.The paper aims to improve the overall processing performance of the EDM machine and to achieve the high efficient green and precision machining.The background and significance of the subject were analyzed.Some lack of on current research at home and abroad,and the key points of this study are refined.High efficiency drive technology based on the weight disturbance compensation is researched.Considering the counterweight disturbance caused by the high efficiency servo,technology on real-time compensation precision square technology is presented.Two key fluctuation factors are extracted and summed up,which are balance force and friction force.Based on one-dimensional flow theory with isentropic adiabatic feature,balance-force fluctuation model is put forward.According to principle of Stribeck,the improved friction-force fluctuation model is also given.Considering the PMSLM's flux equation,the dynamic compensator method is developed to suppress the counterweight disturbance,combining with the double PID uncoupling and fuzzy PID self-adaptive parameter adjustment.Simulation and experimental comparison results show that the use of weight disturbance compensation control vertical linear motor drive,not only greatly inhibited the crawling and chattering variations when the spindle high and low drive,but the response tracking speed is faster and the overshoot has been significant improvement.The spindle position error has been significantly reduced and high efficient drive is achieved.Compensation technology on the electrode wear sophisticated is researched.Due to the electrode wear,the EDM precision is dropped,and method of pre-distortion compensation electrode is proposed to achieve complete precision molding throughout by one electrode,avoiding the replacement of the electrode to improve the machining precision and efficiency.According to different working conditions,we developed different pre-distortion technologies:in fine loss condition,offset compensation technique on the curvature is proposed;in large loss,layered compensation method based on hierarchical discharge gap is proposed.Simulation and experimental verify the proposed compensation technologies,and the geometric mean error of the molded part has reached the standard EDM precision molding.Green technology based on the water curtain mist purification is researched.Research based on processing technology.The mechanism of discharge machining ionization smoke generation and diffusion are analyzed.To reduce the influence on the spindle accuracy from the smoke and improve the environmental friendliness,a water curtain purge hood is designed.Construction of a water curtain is formed based on the water-attaching theory and the water curtain continuity equation model is constructed by the primary crushing theory.The whole process of the jet from the outlet to the water curtain is studied systematic.Four typical factors,the jet velocity,angle of incidence,wall length and wall inclination,are used to analysis the affection on the degree of difficulty,the length of the water curtain and curtain quality.A spindle hood and cycle purification technology is designed to achieve the green machining.Integration application platform based on the key technologies is developed.Focus on the integrate application of the key technologies,the high efficiency servo technology,precision molding technology and green processing technology are integrated into the prototype,and the machine has been designed and developed to verify the EDM machining overall performance developed by this paper.Finally,research content and the major innovation are summarized,the further research directions are given combined with the future development of EDM machining.