哈尔滨工业大学数控技术大作业.pdf

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1、数数控控技技术术课课程程（20142014）大大作作业业院院（系）（系）机械设计制造机械设计制造专专业业姓姓名名学学号号班班号号任课教师任课教师完成日期完成日期及其自动化及其自动化韩振宇韩振宇2014.42014.4哈尔滨工业大学机电工程学院20142014 年年 3 3 月月说说明明一、大作业应包括下列主要内容：1.目录；2.题目 1 的要求（精简版）与报告；3.题目 2 的要求（精简版）与报告；4.题目 3 的要求（精简版）与报告；5.其他内容二、注意事项：1.报告可以打印，也可以手写，手写的请扫描后粘贴入 word 文件中，形成电子文档；2.调研部分，不要为了凑字数，而撰写大量无关内容。

2、字数不重要，重要的是对调研内容的自我总结；3.在大作业的最后，如果愿意，可以谈一下对课程的感受和建议；4.报告的电子版请以班级为单位，刻录在光盘中交给任课教师。三、报告请用 A4 纸双面打印，左侧装订，统一交给任课教师，以备检查。四、此说明页请勿删除。目目录录作业一.2作业二.8作业三121作业一：CNC ApplicationsCNC Applications IntroductionThe many unique features of a PCNC create a versatility that allowsit to be used in a wide range of appli

3、cations.Below are some of theinstances that illustrate how the unique value and features of the machinecan have a substantial impact on the cost or success of an application.Engineering Prototype,Research and DevelopmentToooftenengineersfindthemselvessqueezedbetweentheR&Ddepartment and the productio

4、n machine shop.Heres a typical scenario:In a CNC machine shop with high speed machining centers,the shop runsefficiently:the expensive machinery is kept busy with a well-plannedjob queue of production parts.Materials,machine time,tooling,jigs,fixtures,and all the rest have been carefully synchronize

5、d for continuousflow and high productivity.In the middle of it all,a wild-eyed R&Dengineer shows up with a poorly documented sketch;he wants the parton his desk the next morning.Production schedules snarl with developmentschedules.Cost accounting is fudged,and then some people wonder whythe producti

6、vity of the machine shop seems to be dropping.Sales peoplewonder why the new developments take so long.Its all very Dilbert.Personal CNC offers an alternative.Its low cost makes it perfectlysuited to one-off designs.A PCNC allows engineering departments to keepa machine at the ready,dedicated solely

7、 to R&D work.There are manybenefits to this approach.The prototype turn-around time is quicker,the product designers gain a clearer understanding of the manufacturingprocess,and consequently the final design is easier to manufacture whenthe production model shows up in the job queue of the productio

8、n machineshop.Development with the use of a PCNC is more efficient,and allowsa clear separation of the cost accounting of the daily conventionalmanufacturing processes from the costs of development.Secondary OperationsExpensive production machines can support their high cost only whenthey are kept o

9、ccupied in high value processes.A PCNC would not normallybe considered a production machine tool,however,when it is judiciously2applied in secondary operations,it can leverage the productivity ofother machines.Consider this case:a block of aluminum needs 12 minutes and 6 toolson the front side and 6

10、 minutes with a single tool on the back side.Doing 100 pieces will take 1800 minutes.Thats 30 hours of time forthe operator and the vertical machining center(VMC).Now consider the alternative of running a VMC with a PCNC 1100parkedoff to one side.The operator passes the work from the VMC to the PCNC

11、1100.The 6 minutes on the backside takes 8 minutes on a PCNC 1100,butits done during the 12 minute operation.The total operator time dropsto 1200 minutes instead of 1800 minutes.The use of the PCNC 1100 forsecondary operations in this situation saves 33%on labor cost and 23%on capital equipment cost

12、.(note below)Because the PCNC 1100 runs on 230 VAC single phase and the PCNC 770on 115 VAC and are easily moved with a pallet jack,the they can be movedaround the machine shop for secondary operations wherever it is needed.NOTE:Assuming were operating a$45,000 VMC and a$7000 PCNC andlooking for 100%

13、payback on 2 years of 1 shift operation.This is 4000hours of operation.The VMC by itself has a machinery time cost of$11.25per hour($45,000/4000 hrs).The VMC+PCNC has a machinery time costof$13.00 per hour($52,000/4000 hrs).Without secondary operationwe have 30 hours at$11.25 or$337.50.With the seco

14、ndary operation setupwe have 20 hours at$13.00 or$260.The machine time cost of$260 is77%of$337.50,a 23%savings.Short Run/Rapid ResponseThe conventional VMC requires a well-established G-code program fortrouble-free operation.When the machinist is faced with a situationrequiring short runs and rapid

15、delivery of new designs,it simply isntpractical to develop a full G-code program.Working in a mixed mode,with manual operations,conversational mode,and partial G-code segments,is most easily accomplished with an open machine.In these situationshigh-speed rapids are a liability,not an asset.A PCNC mi

16、ll worksexceptionally well under those conditions.Bootstrap Entrepreneur3Starting a new business is always a high-risk operation.The highcapital cost of fully automated equipment is difficult to justify andoften impossible to finance without a proven business plan.A PCNC canget you started at very l

17、ow cost.By using a PCNC instead of a fullyautomated VMC during startup,your business plan will have significantlylower capitalization costs and slightly higher labor costs.This is a classic bootstrap technique:it gets you up and runningand proves the plan.Once the business is established and the sal

18、es aredemonstrated,it becomes much easier to justify an investment in moreautomated equipment.Hobby Business/Midnight EngineerThere are few things more rewarding than developing your own productor invention.It may lead you to untold wealth,or simply keep you outof the bar.But youll never know unless

19、 you try.Many people try to start a new business while keepingtheir day job.One of the problems of this approach is the difficulty in establishingrelationships with local machine shops when youre limited to workingevenings and weekends.Your contractors will probably be unable orunwilling to meet you

20、 on your time;they may not consider you to be animportant customer.You may have trouble getting what you need when youneed it.However,if you can produce your own prototypes and short runsof production,you will reduce your cost,your frustration,and the timebetween your initial idea and final product.

21、EducationThe best educational tools both demonstrate theory and allow actualpractice.Until the development of the PCNC 1100,the machinery designedfor education limited students to working with machinable wax,plastic,or perhaps some light metals.While interesting,it allows little morethan a demonstra

22、tion of machining theory.To move beyond theory and into practice requires a machine capableofperforminggenuineindustrialprocesses:cuttingsteel,iron,stainless,and even tougher nickel based alloys.With its serious accuracyand real world capability,a PCNC can offer your students a muchgreaterunderstand

23、ing of the way things work,the processes of manufacturing,4and the needs of industry.Hobby AvocationsWhether youre rebuilding antique cars,building a custom bike,orcreating a homebuilt aircraft,the ability to cut three-dimensionalshapes in a wide variety of materials is essential.We find it particul

24、arlyodd that some people consider a$7000 tool to be just too expensive forhobby use,yet they wont blink an eye at$10,000 snowmobiles,$15,000fishing boats,and$65,000 SUVs.Unlike many other kinds of hobbyequipment,a quality tool is an investment that has both immediate paybackin personal rewards,and l

25、ong term payback in high resale value.If yourdream involves making things,we encourage you to make it happen.Manufacturing EngineeringSome people would cringe at the idea of taking a brand new CNC milland ripping into it to make it into something else,but that very ideamakes a lot of sense to manufa

26、cturing engineers.Building a new automatedmanufacturing system is always an expensive undertaking.However,thatnew system made from pieces or sections of the a PCNC is often lessexpensive than a line built from new,raw components.Whether its asingle work cell or a large scale integrated line,manufact

27、uring systemsnormally have precision motion with multiple axes.Because the PCNC 1100has an open architecture,it would be a simple matter for a trainedengineer to do a bit of rewiring for PLC control.Perhaps the spindlewould be replaced with an adhesive applicator or ultrasonic plastic welder.Maybe n

28、othing more than a Z axis,spindle,and column would be used.For a manufacturing engineer,the PCNC 1100 can be a building block forthe creation of larger systems.NGO,Developing Nation ProgramsThere are a variety of non-government organizations(NGOs)pursuingprograms to advance poor and developing natio

29、ns.Micro-finance and smallenterprise development projects provide funding,advisors,and supportfor individuals and small groups with entrepreneurial aspirations.Manufacturing in the modern world is easily done with CNC,however,inunderdeveloped nations the barriers hindering the application of CNCtech

30、nology are enormous.Beyond the obvious financial hurdles,there5areconsiderableproblemsofinsufficientinfrastructure.Without3-phase power,without factory service technicians,and without spareparts sources,conventional CNC manufacturing is simply out of thequestion.A PCNC,however,offers modern world CN

31、C technology,but witha design for robust operation,user maintenance,and single-phase power.Delivering the same accuracy as a conventional CNC,but operating atlower speeds without an automatic tool changer,a PCNC is the perfectmachine for entry into modern manufacturing in places where labor ischeap,

32、people are motivated,and the conventional infrastructure is weak.We at Tormach would welcome discussion of CNC related projects incooperation with established NGOs that may be interested in bringingmodern manufacturing methods to underdeveloped nations.In our view,success would require a small clust

33、er of machines,a supply of spareparts,and at least one knowledgeable support staff person.Some Industries where CNC Machining Centers are usedIndustries for removing metal:The metal removing industries removethe metal from the raw material to give it the desired as per therequirements.These can be t

34、he automotive industries for making the shafts,gears,and many other parts.It can be manufacturing industries for makingthe various rounded,square,rectangular,threaded and other jobs.Thereare many other industries where the metal removal works are performed.All these metal removal works are performed

35、 by different machine toolslike lathe,milling machine,drilling machine,boring machine,shapingmachine,reamer,etc.Traditionally these machines are operated by theoperators,but the CNC versions of all these machines are now usedextensively.You can carryout almost all machining operations with theCNC ma

36、chining centers.You can also carry out all the turning operationssuch as facing,boring,turning,grooving,knurling,and threading onyour CNC turning centers.On your CNC grinders you can carry out thegrinding of the internal diameter,outer diameter,and also the flatsurfaces.The Contour Grinding technolo

37、gy enables you to grind surfacesof all shapes.Industries for Fabricating Metals:In many industries thin plateslike steel plates are required for various purposes,in fabricationsindustry the machining operations are performed on such plates.In these6industries the CNC machines are used for various ma

38、chining operationslike shearing,flame or plasma cutting,punching,laser cutting,forming,and welding and many other applications.To bring the plates to theirfinal shape CNC lasers and CNC plasma cutters are used commonly.To punchthe holes in the plates of all sizes CNC turret punch presses are used.An

39、d if you want to bend the plate so as to give it a final shape,youcan use CNC press brakes.In some cases the CNC back gages are coupledwith the shearing machines,this enables controlling the length of theplate to be sheared as for different applications.Electrical Discharge Machining(EDM)Industry:Th

40、e EDM machinesremove the metal by creating the sparks that burn the metal.There aretwo types of EDM with the CNC automation Vertical EDM and Wire EDM.The Vertical EDM needs an electrode of the shape and size of the cavitythat is be made in the job.Wire EDM is used to make the punch and diecombinatio

41、ns for the dies set that are used in the industries wherefabrication is done.Other Industries where CNC machines are used:CNC machines are alsoused extensively in the wood working industries to perform variousoperations like routing(similar to milling)and drilling.CNC technologyis also used in numbe

42、r of lettering and engraving systems.There arealso CNC machines for the electrical industry such as CNC coil winders,and CNC terminal location and soldering machines.In whichever the industry you go you are sure to find some or theother type of the CNC machine.The progress made by the manufacturings

43、ector is mainly due to the advancements in the CNC technology.参考文献1 曹淡 数控机床应用与维修 电子工业出版社，1994年2 魏弦 数控机床的应用及维护 中国学术期刊 2007年10期7作业二：典型曲线数字积分法插补方法DDA 法抛物线插补的积分表达式对于抛物线：两边微分有：整理得即则可得 DDA 抛物线插补积分表达式令，则：式中 N 为积分累加器的位数显然用 DDA 法进行抛物线插补时，是对切削点即时坐标 Yi 与 p 的数值分别进行累加，若累加器产生溢出，则在相应坐标方向进给一步插补器结构框图据抛物线的 DDA 插补积分表达

44、式，可知插补方法如下：每次产生一个控制脉冲，X、Y 积分器则迭代累加一次，溢出时相应坐标轴进给一次，Y 积分器的溢出8还要对 X 被积函数寄存器进行修正。画出插补器结构框图如图所示图 3-1 抛物线插补器结构框图JVX、JVY 分别为 X、Y 被积函数寄存器JRX、JRY 分别为 X、Y 积分累加器终点判别分别判断 XY 坐标轴进给步数，当 XY 坐标均到达终点时插补结束。插补举例插补第一象限抛物线，起点为(0,0)，终点为(8,4)，插补脉冲计算过程如表 1 所示，插补轨迹如图1 所示。两坐标进给步数分别为8和 4，一旦某坐标进给步数达到要求则停止该坐标方向的插补运算。表 1 插补运算过程运

45、算X 积分器X 终Y 积分器Y 终次序JVXJRXJVYJRYXY(Yi)(p)(Yi)(p)0123456780000000000000000000000000000000000000000000000000000000000000000000000000000000001000100010001000100010001000100010000001000100010001000100010001000100010000000100100011010001010110011110000000000000100010001000100010001000100010001009910111213

46、141516171819202122232425262728293031323334353637383940414243444546474849505100000000000000000000000000000000000100010001000100010001000100010001000100010001000100010001000100100010001000100010001000100010001000100010001000100010001000100011001100110000000000000000000000000000000000010010001101000101

47、011001111000100110101011110011011110111100000010010001101000101011001110000000100100011010001010110011100000001101101001000000000000000000000001000000010000000100010001000100010001000100010001000100010001000100010001000100010001000100010001000100010001000011101110111011101110111011101110110011001100

48、110011001100110011001010101010101010001000100010001000100010001000100010001000100010001000100010001000100010001000100010001000100010001000100010001000100010001000100010001000100010001000100010001000100010001100110101011110011011110111100000001001000110100010101100111100010011010101111001101111011110

49、000000100100011010001010110011110001001101010111100110111101111000000010010001100000001000000000000000100000000000000010000100010001000100010001000100001100110011001100110011001100110011001100110011001100110011001100100010001000100010001000100010001000100010001000100010001000100001000100010001105253

50、545556575859606162636465666768697071720011001100110011001100110011001100110011001100110011010001000100010001000100010001001100111100100101100010111110000101000111101011010000010010001100000001001000110000000010000100001000100010101010101000100010001000100001100110011001100110010001000100010000100010