自动化的切割工具选择和切割工具序列优化为旋转的零件外文文献翻译、中英文翻译_第1页
自动化的切割工具选择和切割工具序列优化为旋转的零件外文文献翻译、中英文翻译_第2页
自动化的切割工具选择和切割工具序列优化为旋转的零件外文文献翻译、中英文翻译_第3页
自动化的切割工具选择和切割工具序列优化为旋转的零件外文文献翻译、中英文翻译_第4页
自动化的切割工具选择和切割工具序列优化为旋转的零件外文文献翻译、中英文翻译_第5页
已阅读5页,还剩16页未读 继续免费阅读

下载本文档

版权说明:本文档由用户提供并上传,收益归属内容提供方,若内容存在侵权,请进行举报或认领

文档简介

Automated cutting tool selection and cutting tool sequenceoptimisation for rotational partsAli Orala,* M. Cemal CakirMechanical Engineering Department, Uludag University, Bursa, TurkeyAbstract:The aim of this work is to define computer-aided optimum operation and tool sequences that are to be used in Generative Process Planning System developed for rotational parts. The software developed for this purpose has a modular structure. Cutting tools are selected automatically using the machinability data, workpiece feature information, machine tool data, workholding method and the set-up number. An optimum tool sequence is characterised by a minimum number of tool changes and minimum tool travel time. Tool and operation sequence for minimum tool change are optimised with a developed optimisation method that is based on “Rank“Order Clustering2003 Elsevier Ltd. All rights reserved.Keywords: Computer-aided process planning; Tool selection; Operation sequence; Tool sequence; Optimisation.1. IntroductionThe first step and one of the main objectives of a computer integrated manufacturing system is to integratethe computer-aided design (CAD) and computeraidedmanufacturing (CAM) components. The total integration of these two components into a commonenvironment CAD/CAM is still under development.Many of the major developments have been uncoordinatedand there is a great deal of overlap in terms of their intended functions. For example, the present CAD/CAM systems have their strength in geometricaldefinition, i.e., CAD component and CAM is mostly limited to CNC programming. Other important intermediateelements such as process planning are not included. This is due to the fact that the numericalinformation generated by a CAD system is not sufficientfor process planning. Computer-aided process planningsystems available in the market are incomplete andlimited when compared to the number of CAD andCAM systems available 1.Process planning is an activity, which determinesappropriate procedures to transform a raw material intofinal product. In manufacturing industry, the taskof process planning mainly consists of determiningthe usage of available resources, such as machinetools, workholding devices, cutting tools, generation ofoperation sequence, determining machining parameters(i.e., cutting speed, feed rate, depth of cut) and selectionof auxiliary functions 2.The production cost of a component depends uponcost of the workpiece material, tooling cost and overheadcosts. Generally, these costs associated withmachining a part are fixed; thus the only scope toreduce the overall cost of the part is to focus on thetooling cost. Selection of optimal tooling directly affectsthe part cost 1. In the view of the significant reductionsin cost that can be obtained by selecting the correctcutting tool and its associated optimum cutting conditions,it is considered that any selection system that doesnot take into account all of the relevant technologicalparameters has several limitations 3. Production time isdefined as the machining time plus non-machining timeto machine a component. Determination of optimalsequence cutting tools on turret magazine of a CNCmachine tool is an important task for achievement ofoptimal machining sequences for reducing total nonmachiningtime 4.The aim of this work is to define computer-aidedoptimum operation and tool sequencing to be used inthe generative process planning system developed forrotational parts (GPPS-RotP).2. State-of-art of cutting tool selectionThe objectives of tool selection exercise are to selectthe best tool holder(s) and insert(s) from availablecutting tools database. In the past, the operator wouldselect the best tool set according to his experience, whichcannot be converted into logic or algorithmic rules. Thismethod is called as manual approach, which commonlyresults in errors and inconsistencies. Disadvantages ofmanual approaches led to development of automatedapproaches that aimed to reduce the probability oferrors and inconsistencies. The correct choice of cuttingtools is determined by the overall part configuration,rather than by individual contour section or workpieces.Computer-aided tool selection systems have been developedfor this purpose. Plummer and Hannam 5 tookworkpiece material and profile geometry into accountbut ignored selection of carbide grade, chipbreaker,cutting edge length, and nose radius. Giusti et al. 6developed the expert tool selection module for turningoperations. This module depends heavily upon theexpertise of the operator for an efficient structuring ofthe rule-based approach. Chen et al.7 developed anautomatic tool selection system for rough turning on aCNC lathe. Selection is made from appropriate toollibrary employing a heuristic method in order to reducethe search time. Tool selection procedure searches forthe best tool for a desired operation. Out of the variouspotential tools, the only criterion for tool selection isleast cost. Chen and Hinduja 8 used a tool selectionprocess by checking collision between tool and workpieceor machine tool for workpiece to be machined. In case of any collision, use of two or more tools formachining is considered.Hinduja and Huang 2 carried out a study called OPPLANin which they assumed that single tool was usedfor recess or groove machining. Domazet 9 used ahybrid approach in that both algorithms and productionrules matrix method were used for tool selection; cuttingconditions were determined using tool manufacturerdata. Fernandes and Raja 1 carried out tool selectionprocess for external and internal turning, but theyconsidered only cylindrical and face turning operations.Edalew et al. 10 developed a computer-based intelligentsystem for automatic tool selection system. Thissystem was operated in a fully interactive mode andinformation associated with a particular subject, such aspart status, feature ordering (up to 12 feature typescould be used to describe the component) and thecomponent materials were incorporated into system.The analysis of the component included feature specificationand dimensions, which were entered by the user.3. Tool selection parametersSuccess in metal cutting depends on the selectionproper cutting tool both in respect to the tool andmaterial to be machined. The elements that influence thetool selection decision are: (i) workpiece materials, i.e.,chemical and metallurgical state, etc., (ii) part characteristic,i.e., geometry, accuracy, finish and surfaceintegrity, etc. (iii) machine tools characteristics includingthe workholder, tool number of the tool magazine andtool holder dimension, (iv) cutting tools or insertcharacteristics 11.Cutting tools selection is a very important subtaskinvolved in process planning systems. Tool selectionmodule uses knowledge such as geometry for workpiece(feature recognition), surface finish, shape, location anddirection tolerance, material of the workpiece, machinabilitydata such as speed, feed rate, depth of cut,machine tool, set-up number, process type, workholdingdevice. GPPS-RotP has seven modules as shown inFig. 1.3.1. Feature recognitionThe first step in automatic process planning activitiesis recognising the geometry of workpiece. Featurerecognition is a design interface for process planningwhich is an automatic transfer of part description datafrom CAD system to process planning system 12. Thepart-feature recognition system that is developed has gotsimilarities with syntactic pattern-recognition techniquedeveloped by Fu 13. Fu used 24 pattern primitives toformalise the pattern-recognition process. In the presentwork, 16 pattern primitives were defined as shown inFig. 2. They are basically different shapes of line and arcsegments with a start point, end point and a direction.Turning surfaces can be defined an elements such asdiameter, taper, face, arc, chamfer, recess or groovingwith the aim of pattern primitive. For example,a diameter can be represented by either the patternprimitive “A” or “C”, a face can be represented by ”D”or “B”.In recognition, features are classified into two groups:primary features and secondary features as shown inFig. 3. Primary form features are cylinder, taper andarcs. Secondary form features are form features otherthan cylinders, tapers and arcs often found on rotationalcomponents. Giving only the upper half of the 2Dprofile information, which is a series of lines and arcsegments, does the definition of the geometry of arotational part.4. Cutting tool selectionCutting tools that are considered consist oftwo main components: the tool holder and indexableinsert. The objective of any tool selection is todetermine several parameters such as tool holder(clamping system, type, point angle, hand of cut, size,etc.), insert (shape, size, grade, nose radius, etc.),cutting conditions (in this work insert size isdetermined according to specified cutting data), typeof coolant (if required) and total cost of machining thecomponents 17.The outline for selecting indexable turning toolselection is first to select the tool holder system, followedby the tool holder and finally the suiting insert. In thepresent work, tool selection is feature based and fullyautomatic. Required information for tool selection are:machinability data, feature recognition for workpiece,machine tool to be used, workholding device and initialoperation sequence.Initial operation sequence consists of four basic steps:machining of right-external zone (if workpiece consistsof two zones, right zone has machining precedence),machining of right-internal zone, machining of leftexternalzone, machining of left-internal zone. Initialoperation sequence is changed automatically accordingto the clamping surface defined by clamping methodmodule.The selection of tool holders is based on the basicmachining operations required to transform theworkpiece into desired shape. The first check is thatthe tool holder is of a suitable overall type. Certaincritical dimensions of the cutter must also bechecked against the shape of the operation, such aseffective cutting edge length and gauge length. Theoverall size of the tool must also fit into the machinetool magazine 18.4.1. Cutting tool selection for rough turning operationsThe various geometrical parameters definingindexable inserts for turning tools are included in ISOcode. Tool selection module not only takes theparameters in the ISO codes into consideration, butcarbide grades and functions of tools as well. In thepresent work, inserts with 95_ of approach angleand 80_ of point angle are considered firstfor rough turning operations. This enables them tomachine stepped profiles without any geometriccollision problem.4.2. Tool selection for recess and groove turningIn comparison to tool selection criteria used for roughturning, more comprehensive tool selection criteriashould be used for recessing and grooving.The recess term used in this paper refers to a featurethat has a minimum width of 16mm and that can bemachined by one or two tools of opposite hands 2. Thestudy reported herein adopts this definition. Yet it doesnot use this definition as a sole criterion for cutting toolselection for groove and recess. The width of a feature iscommonly used as a criterion for classifying it as a groove.If no accessibility problem occurs during machining, thenanother cutting tool other than grooving tool can beselected. The characteristics of the features such as width,depth, and concave, convex and taper parts should also beconsidered in selecting appropriate cutting tools.In tool selection process, it is necessary to analyse thefeature information through a series of IFyTHENstructures. Thus, appropriate tool holder and insert areautomatically chosen from the tool library. Insert withthe largest point angle is the most preferred one in termsof insert strength, therefore is the starting point. However,large point angle may cause a problem in accessing to thefeature. Accessibility to the feature is then checked for thetool with a smaller point angle. This control routine iscarried on until the most appropriate tool is found. If thiscontrol routine cannot find any appropriate tool forrecessing, the accessibility of two tools to the feature istested via methods of geometric analyses.Different criteria to be used to machine a recess with asingle tool and appropriate tool parameters are given inTable 3. Different recessing methods and tools aresketched in Fig. 11. Recesses that can be machined witha single tool or two tools are shown in Fig. 11a and c,respectively. For any problem in accessing to the featurewith all available tools, accessibility of the feature usingtwo tools is checked through methods of geometricanalyses. Geometric analyses are applied to check anycollision between workpiece and tool that preventsaccessibility to the feature. If there is any collision, thegeometry of workpiece is temporarily modified as shownin Fig. 11b. For the un-machined region on the recess/groove, another tool with an opposite feed direction ischosen (Fig. 11c). For the temporarily modified geometry,there should be no collision between workpiece and tool tobe able to machine the recess/groove. If no collision isdetected, two tools are assigned for the operation.Geometric analysis in tool selection module ATOS (AutomaticTool Selection Module) is carried out as follows:1. During the last pass of the first tool that does themachining, first contact point K of tool on the groovebase is determined.2. Groove contact point L of the second tool thatfinishes the machining is determined。6. ConclusionIn this work, cutting tool selection was carried out bytaking the geometry of workpiece, surface roughness,chip breaking area of the cutting tools, machinabilitydata, machine tools information, workholding methodsand number of set-ups into consideration. Tools arechosen and operation sequence is then optimised with adeveloped optimisation method that is based on “RankOrder Clustering“.More than 500 practical rules and years of experienceare used in the determination of machinability data,machine tool, workholding method and cutting tools;and the application of the software into practical lifeshows that the system developed is capable of providingfast and successful process plans for complex workpieces.。References1 Fernandes J, Raja HV. Incorporated tool selection systemusing object technology. Int J Machine Tools Manuf2000;40:154755.2 Hinduja S, Huang H. OP-PLAN: an automated operationplanning system for turned components. Proc Inst Mech Eng B1989;203:14558.3 Riberio MV, Coppini NL. An applied database system for theoptimisation of cutting conditions and tool selection. J MaterProcess Technol 1999;9293:3714.4 Dereli T, Filiz IH. Allocating optimal index positions on toolmagazines using genetic algorithms. Robotics Autonom Syst2000;33:15567.5 Plummer JCS, Hannam RG. Design for manufacturing using aCAD/CAM system: a methodology for turned parts. Proc InstMech Eng 1983;197:18495.6 Giusti F, Santochi M. COATS: an expert module for optimal toolselection. Ann CIRP 1986;35(1):33740.7 Chen SJ, Hinduja S, Barrow G. Automatic tool selection forrough turning operations. Int J Mach Tools Manuf1989;29(4):53553.8 Chen SC, Hinduja S. Checking for tool collisions in turning.Comput Aided Des 1988;20(5):2819.9 Domazet D. The automatic tool selection with the productionrules matrix method. Ann CIRP 1990;39(1):497500.10 Edalew KO, Abdalla HS, Nash RJ. A computer-based intelligentsystem for automatic tool selection. Mater Des 2001;22:33751.11 Mookherjee R, Bhattacharyya B. Development of an expertsystem for turning and rotating tool selection in a dynamicenvironment. J Mater Process Technol 2001;113:30611.12 Kim IH, Cho KK. An integration of feature recognition andprocess planning functions for turning operation. Comput IndEng 1994;27(14):10710.13 Li RK. A part-feature recognition system for rotational parts. IntJ Prod Res 1988;26(9):145175.14 Machining data handbook, Cincinnati machinability, 3rd ed.USA: Data Centre; 1980.15 Tool and manufacturing engineers handbook, vol. 1. Machining.Dearborn, MI: Society of Manufacturing Engineers; 1983.16 Hinduja S, Huang H. Automatic determination of work-holdingparameters for turned components. Proc J Eng Manuf B1989;203:10112.17 Arezoo B, Ridgway K, Al Mahari AMA. Selection of cuttingtools of machining operations using an expert system. ComputInd 2000;42:4358.18 Carpenter ID, Maropoulos PG. A flexible tool selection decisionsupport system for milling operations. J Mater Process Technol2000;107:14352.19 Tool Catalog, turning tools. Sandvik Coromant, 2000.20 Singh N. Systems approach to computer-integrated design andmanufacturing. New York: Wiley; 1995.自动化的切割工具选择和切割工具序列优化为旋转的零件阿里, *, M. Cemal Cakir机械工程部门, Uludag 大学, 伯萨, 土耳其摘要:这工作的目标将定义将被使用在生产过程的计算机辅助的最宜的操作和工具序列规划系统显现了出为旋转的零件。软件被开发为这个目的有一个模件结构。切割工具是自动地选择使用可切削性数据, 制件特点信息, 机械工具数据的方法和设定数字。一个最适宜的工具序列为工具变动和极小的工具旅行时间的一个最小数字描绘。工具和操作序列为极小的工具变动被优选以根据等级的一个被开发的优化方法命令成群“。 2003 年Elsevier 有限公司。版权所有。主题词: 计算机辅助的过程计划; 工具选择; 操作序列; 工具序列; 优化。1. 介绍第一步和a 的当中一个主要宗旨计算机集成制造系统将集成计算机辅助设计(CAD) 并且计算机辅助制造的(CAM) 组分。共计这两个组分的综合化入共同性环境CAD/CAM 仍然是在发展中。许多主要发展不协调并且有很多交叠根据他们的意欲的作用。例如, 礼物 CAD/CAM 系统有他们的力量在几何定义, 即, CAD 组分和CAM 主要是对CNC 编程限制。其它重要中间体元素譬如处理计划不是包括。

温馨提示

  • 1. 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
  • 2. 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
  • 3. 本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
  • 4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
  • 5. 人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对用户上传分享的文档内容本身不做任何修改或编辑,并不能对任何下载内容负责。
  • 6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
  • 7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。

评论

0/150

提交评论