NGHIEN cufu - TRAO DOI JDESIGN OF AUTOMATIC PIPE PROFILE CUTTING MACHINE BY CNC CONTROL THIET KE MAY CAT BifiN DANG N G T U D O N G DIEU KHIEN CNC Msc Phan Huy Le, AssocProf.PhD Bui Van Hanh Department of Welding Engineering and Metal's Technology- School of Mechanical Engineering Hanoi University of Science and Technology ABSTRACT The manufacture of auto-lifred oilrig and the oil pipeline system in the petroleum refinery are important projects, occupying a large volume in Vietnam's industry In such works, the process of making structural system from steel tube is mostly works The tube cutting especially at the intersection of multiple tubes, is required to have accurate edges It is important to have precision gap welding in progress of assembly welding after that Manual cutting has the disadvantages such as low productivity, wide, inexactly gap welding, wasting welding metal, leading to increase stress, strain in the intersections of the tubes The solution automatically CNC controlled cutting causes the increasing performance, beautiful cutting edge, steady gap welding This report introduces the result of research, design automotive cutting system It includes four sections; design calculation mechanical system, building equation of machine's orbital, design controller and control algorithms Keywords: CNC, Automatic pipe profile cutting, oilpipe, nut TOM TAT Viec che tao chdn gidn khoan ddu vd cdc he thdng dudng ong ddn ddu, cda cdc nhd mdy Igc ddu dang la cdc cong trinh quan trgng, chiem khdi lugng ldn cong nghiep Viet Nam Trong cdc cong trinh do, viec che tao ket cdu he dng ddn td phoi thep dng chiem chu yeu Viec cat cdc ong dd yeu cdu diit chinh xdc cao nhdm ddm bdo khe hd hdp ly cho qud trinh hdn lap ghep he thong ong ve sau, ddc biet Id tai cdc nut giao cda nhieu dng PhUdng phdp cat thu cdng cd nhuac diem la cho ndng sudt thdp vd ddc biet Id khe hd hdn ldn ldm tang lUdng kim loai dip din den ldm tdng dng sudt vd bien dang tcii nut giao cua cdc ong Gidi phdp cat tU dgng dieu khien CNC cho ndng sudt cao vd mep cat dep, khe hd hdn dong deu Bieu dd cho phep nhdn dudc mdi hdn cd chdt lUdng cao, it cong venh, hien dang Bdi bdo gidi thieu cdc ket qud nghien cdu tinh todn thiet kl mdy cat hien dang ong tU dgng dieu khien CNC ldm viec tqi hiin trudng Ndi dung bao gom cdc phdn; Tinh todn thiet kehe thong ddn dgng vd truyen dgng xdy diing phudng trinh quy diio cat cho mdy, thiet kehe thong dieu khien vd xdy dung thudt todn dieu khien Tii khoa: CNC, cat dng tU dgng ong ddn ddu, nut TAP CHf CO KHf V I £ T NAM, Sd nSm www.cokhivietnam.vn 2014 NGHIEN cufu-TRAO DOI INTRODUCTION In fact, to cut pipes follow the intersection of two pipes before welding, there are many different ways classified two main types: cut manually or by machine Commerciahzed pipe cutting machines are many different types such as large pipe cutter CNC controls, small cutter on the surface of the pipe follow fixed rails, equipment or tube beveling cutting machining On the large mower, the cutter head has 3-axis motion and tubes rotate However, the actual production requites to cut the tube to achieve high accuracy right on the site To solve this demand, it is forced to use CNC cutting machines Nevertheless, in Vietnam, the available CNC cutting machines are large, operate on the principle of rotating pipe during cutting and cutting machines are fixed in the workshop The inconvenience of this kind of cutter is hard to induct and dismount tubes on the site On the other hand, rotating the tubes, which have large site and volume (12 m length, diameter from 400 mm to 1000 mm, average thickness 40 mm) requires a lot of energy From above analysis, the authors have proposed design solutions orbital cutter CNC pipe work at the site according to the principle of spinning tube cutter, tube fixes in the cutting process BUILDING SOLUTIONS Through analyzing the existing design of the cutter, the authors have chosen the following solutions: • This machine is portable cutting machine, using plasma or acetylene-oxygen flame to be able to cut various metals, including nonferrous metals This cutting machine has compact size, small volume (2J2A,.siii(e,)J„4j-.sil(