188宝金博页面版

Machine based energy-saving tool path generation for f i ve-axis endmilling of freeform surfacesKe Xua , Ming Luo b , Kai Tang a , b , *a Department of Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology, Hong Kongb Key Laboratory of Contemporary Design and Integrated Manufacturing Technology, Northwestern Polytechnical University, Chinaa r t i c l e i n f oArticle history:Received 22 July 2015Received in revised form23 August 2016Accepted 29 August 2016Available online 30 August 2016Keywords:Five-axis machiningEnergy consumptionTool path generationMachining eff i ciencyPotential f i elda b s t r a c tEnergy consumption in f i ve-axis machining can be extremely large, especially for processing large-sizedparts such as blades and dies, which often take hundreds of hours to machine. Once the specif i c machinetool conf i guration is given, one important objective in planning a f i ve-axis machining operation is toreduce the total amount of energy consumption, which is not only particularly pertinent for mass pro-duction type operations but also plausible in today's energy-conscientious environment. While pastresearch in this subject has been mainly focusing on f i nding better machining or processing parameterssuch as the cutting depth, feed rate, spindle speed, etc., in this paper, we study the fundamental problemof how to plan a f i ve-axis tool path for machining an arbitrary free-form part surface on a given type ofmachine tool so that the total amount of energy consumption can be reduced, as compared to a tradi-tional tool path, with everything else e e.g., the cutting depth, feed rate, spindle speed, maximumscallop-height, etc. e being equal. Towards this goal, an algebraic model called machine dependentenergy potential f i eld is formulated on the part surface, which encapsulates the specif i c power demandat any cutter contact point and along any feed direction. With this potential f i eld, a simple tool pathgeneration method is proposed that strives to f i nd a good balance between the best f i tting to the po-tential f i eld (to minimize the total energy consumption) and the desired streamline patterns of the toolpath. Experiments of the proposed method are carried out in both computer simulation and physicalcutting, and the results are compared with that of some popular tool path generation methods such asthe iso-scallop height method. The remarkable more than 25% savings in total consumed energy by theproposed method conf i rm the original motivation e designing better tool paths adaptive to the givenspecif i c machine tool is a powerful approach to reducing the total consumed energy, perhaps in generalmore effective than the passive selection of machining parameters which often have little room to adjustdue to many constraints (e.g., the feed rate is highly regulated by the machine's controller during thecutting).© 2016 Elsevier Ltd. All rights reserved.1. IntroductionFive-axis milling is extensively used in machining complexsurfaces with high accuracy requirements. In industries like aero-space and ship building, complicated parts such as blisks or turbineblades are exclusively manufactured by means of f i ve-axis milling,at least for the semi-f i nishing and f i nishing operation. Due to thelarge size and also in general the extraordinary hardness of thematerials of these parts, they usually take many hours (even days)to machine and, as a direct result, require a huge amount of(electricity) energy. Even in the lesser case of lighter industries, theamount of energy consumed by CNC machine tools is formidable.For example, according to (Gebert, 2007), on average, assumingrunning 24 h a day for a total of 24,000 h, an ordinary CNC machinetool will consume about 22,000 Euro worth electricity, which ismore than one third of its total operational cost (including labor,repairs, the spindle heads, depreciation, etc.). Since, unlike moldsand dies, parts such as a blisk for an aero engine are of mass pro-duction type whose designs usually remain unchanged for decades,even a small reduction in the unit cost of energy consumptionwould mean a huge saving in the long term.A typical f i ve-axis machining process comprises three* Corresponding author. Department of Mechanical and Aerospace Engineering,Hong Kong University of Science and Technology, Hong Kong.E-mail address: mektang@ust.hk (K. Tang).Contents lists available at ScienceDirectJournal of Cleaner Productionjournal homepage: www.elsevier.com/locate/jcleprohttp://dx.doi.org/10.1016/j.jclepro.2016.08.1400959-6526/© 2016 Elsevier Ltd. All rights reserved.Journal of Cleaner Production 139 (2016) 1207e1223基于机床的自由曲面五轴立铣削节能刀具轨迹生成