Research On Enveloping Machining Technology Of Extrusion Screw With Finger Cutter

Along with the rapid development of plastic material using in industry, agriculture anddaily life, all kinds of spiral extrusion commixture technology are widely used in the plasticsforming industry. As the key part of extrusion technology, the shapes of extrusion screw aremore and more complicated; the processing technology also takes more and more people'svalue. How to enhance the processing quality of the extrusion screw, the processing efficiencyas well as how to reduce the cost have been concerned by present people. The traditionalprocessing method of extrusion screw usually uses forming process processing on theimproving machinery or three axes numerical control machine tool, adopting autogenouslygrinding round angle or conic high-speed steel milling cutter. But along with the improvementof the demand on the shape and function of extrusion screw, the processing efficiency andquality of forming process cannot be satisfied. In the view of complexity of the changeablepitch, changeable bottom diameter, changeable spiral angle of extrusion screw, this articlestudied on the base of studying the theory of geometry characteristic and helicoids forming,the article proposed a kind of highly effective, economical and practical extrusion screwprocessing technology: finger cutter envelope machining. This processing method mayprocess prismatic roundness of extrusion screw with envelope machining efficiently throughthe change of finger cutter's location, and it can realize the complicated processing ofchangeable pitch, changeable bottom diameter and changeable spiral angle in the sameextrusion screw.On the base of studying and summarizing the processing method of free curved surface and spiral curved surface, building the model of processing process, finding the solution by making use of the engage principle and optimization method, in the end this article determines the method and step of the finger cutter spiral curved surface's processing cutting tool space trajectory which uses the finger cutter envelope, designs the mill head which used in the milling cutter envelope to research the processing process of finger cutter's milling cutter, design reasonable processing craft, carry on the error analysis and reduce processing error and analyze the work piece processing and so on a series of key solutions to NC technology of space cutting path, and utilize the C++BULIDER programming language, CAD/CAM software, SOLIDWORKS processing simulation software to realize the above algorithm and the simulation processing process.This research takes the lead in proposing the processing method of using the finger cutter envelope to milling the finger cutter on the base of four axes linkages NC machine in china, and developed the processing machine. It realizes smoother cutting of cutter, higher quality of finger cutter's surface, more efficiency of processing when the finger cutter processed extrusion screw with envelope Machining. The application had broad prospect. This processing method is no doubt changes the national situation of processing extrusion screw as well as played the positive role to enhance the technical level of extruder industry in our country and impel the development of national economy.