Study On Conductive Shaft Of Large Horizontal CNC Electrochemical Machining Tools

The large diameter deep special-shaped inner spiral tubes are widely used in the field of weaponry,aerospace,oil drilling and other fields.Because of their high material hardness,the complex structure of the inner helix and high requirements of forming accuracy,traditional machining can't meet the requirements.Fortunately,electrochemical machining(ECM)has the advantages of not being limited by the properties of the material,no cutting stress and high machining efficiency,making it an important machining method for such parts.The conductive shaft is the core component of the large horizontal CNC electrochemical machining tools.In the process of using high current processing,the conductivity,rotation and sealing performance of the conductive shaft directly affect the stability of electrolytic processing and the quality of electrolytic processing,even determine whether the electrochemical machining can be carried out successfully.The existing conductive shafts are unable to operate stably after a long period of portioning and having a relatively high failure rate.Researching the structural design and performance of conductive shafts is very important.In order to achieve a long and stable operation of the conductive shaft under high current conditions,the thesis analyses the requirements of electrochemical machining(ECM)equipment and the working characteristics of the conductive shaft,proposes a kind of conductive shaft solution to suitable the large horizontal CNC electrochemical machining tools,establishes a geometric model of the conductive shaft.Through finite element analysis software,the static and dynamic characteristics of the conductive shaft are studied,the rationality of the conductive shaft was verified.The conductive shaft temperature field during electrochemical machining(ECM)was simulated and the heat dissipation device was optimized to improve the heat performance of the conductive shaft.The main studies are as follows.Using simulation software combined with comparative analysis,different solutions for the conductive shaft were investigated and a general solution for the conductive shaft was determined.In order to improve the performance of the conductive shaft in terms of conductivity,rotation and sealing,according to the structural characteristics of the conductive shaft and the requirements of the equipment for electrochemical machining(ECM),the key structure of the conductive shaft was designed and a three-dimensional model of the conductive shaft was established.A simulation study for the static characteristics of the conductive shaft was carried out to obtain the static and dynamic characteristics of the conductive shaft,verifying that the designed conductive shaft meets the static stiffness requirements.The simulation analysis of the dynamic characteristics of the conductive shaft was carried out to obtain its low-order inherent frequency and vibration pattern.The results show that the conductive shaft has a good vibration resistance,which initially verifies the rationality of the conductive shaft.The thermal-electrical coupling model of the conductive shaft was established,and the effect of different working conditions on the temperature field was carried out,through the analysis of the temperature field,the distribution law of the conductive shaft was revealed.The thermal-structural coupling model of the conductive shaft was established,and the effect of the temperature field on the structure was analyzed,and the thermal deformation of the conductive shaft was improved to meet the requirements of the conductive shaft.Finally,the designed conductive shaft device was applied to the large horizontal CNC electrochemical machining tools which was developed independently,under the conditions of 15000A current and 5mm/min feed rate,a test was carried out to machine a deep hole part with a shaped internal helix of 160mm inner diameter and 4000mm length.Verifying the conductive shaft can meet the actual processing requirements.