Research On Forming Theory And Machining Technology Of Extruding Screw

Extruding machines are used widely in the rubber and plastics industry because of its special character. With rapid development of the extruding theory and extruding process, and with the deep understanding of extruding material, it occurs kinds of special shape extruding screws. At present, the machining process of the extrusion screws in domestic is behind,the main process of manufacturing extruding screw is by using gernerl lathe and milling machine with forming cutter-tools and by using simple numerical control machine. It is difficult to meet the needs of manufacturing high precision and complex modelling screws. Meanwhile, the method of design stays on by general CAD, it does not adapt to the needs of enterprise development . So, it has vital significance to enchance screws design capability,processing level and productivity by means of researching extruding screws design method,manufacture technology and machining process. The works and results of research in this paper is incarnated as follows:1,Setting up mathematical model of variable lead and conical surface alien extrusion screw Starting from forming theory of helical surface, it provides the basis of the design and machining process of alien extrusion screw.2,Putting forward the parametric design method of alien extrusion screw by using the parametric principle ; Realizing extrusion screw parametric modeling by using Solidworks and achieving the goal of rapid design of alien extrusion screw.3,By means of helical surface shaping theory and single parameter envelope theory , this paper analyses kinds of processing methods of helical surface by using forming cutter-tools. Meanwhile, milling tools shape is calculated by means of Matlab, and the key machining processes of parallel twin-screw are analysed, and its process planning is made.4,Thinking over existing shortcomings of present screw machining process, One new cylindrical screw surface machining process is proposed and its machining mathematical model is set up with milling cutter. This pape analyses machining error and intervene phenomenon of this new process . By compared with traditional processes, this new process has machining efficiency advantage. 5,Analysing CNC processing methods of alien extrusion screw by means of envelope shaping theory and CNC machining principle.