基于注塑模具钢研磨和抛光工序的自动化表面处理

1、译文标题基于注塑模具钢钢研磨和抛光光工序的自动动化表面处理理原文标题Based oon thee injeectionn moldd steeel griindingg and polisshing proceesses autommated surfaace trreatmeent作 者Chao-Chhang AA. Cheen WWen-Tuu Li译 名晁常 温途利国 籍美国原文出处Shiou FFJ, Chhen CHH (20003) Deetermiinatioon of optimmal baall-buurnishhingparametters ffor pllasticc i

2、njeectionn moldding ssteel. Int J Advv Manuuf Tecchnol基于注塑模具钢钢研磨和抛光光工序的自动动化表面处理理摘要本文研究了注塑塑模具钢自动动研磨与球面面抛光加工工工序的可能性，这种种注塑模具钢钢PDS5的的塑性曲面是在数控加工工中心完成的的。这项研究究已经完成了了磨削刀架的的设计与制造。 最佳表面面研磨参数是是在钢铁PDS55 的加工中心测测定的。对于PDS55注塑模具钢钢的最佳球面面研磨参数是是以下一系列列的组合：研研磨材料的磨磨料为粉红氧化铝铝，进给量5000毫米/分分钟，磨削深度220微米，磨磨削转速为118000RRPM。用优化的参数

3、进行表面研磨磨，表面粗糙度度Ra值可由大大约1.600微米改善至至0.35微微米。 用球抛光光工艺和参数优优化抛光，可以进一步步改善表面粗粗糙度Ra值值从0.3443微米至00.06微米米左右。在模具内部曲面的测测试部分，用最佳参数数的表面研磨、抛抛光，曲面表面粗粗糙度就可以以提高约2.15微米到到0 0.007微米。关键词: 自动动化表面处理理 抛光 磨削加工工 表面粗糙糙度 田口方法法 一、引言塑胶工程材料由由于其重要特特点,如耐化化学腐蚀性、低低密度、易于于制造,并已已日渐取代金金属部件在工业中广泛应用。 注塑成型型对于塑料制品品是一个重要工艺艺。注塑模具具的表面质量量是设计的本质要要求

4、,因为它它直接影响了了塑胶产品的的外观和性能能。 加工工工艺如球面研磨、抛抛光常用于改善表面光光洁度。研磨工具(轮子子)的安装已已广泛用于传传统模具的制制造产业。自动化表面面研磨加工工工具的几何模型将介绍。自动化表面面处理的球磨磨研磨工具将得得到示范和开发。 磨削速度, 磨磨削深度，进给速速率和砂轮尺寸、研磨材材料特性（如磨料粒度度大小）是球形形研磨工艺中主要的参数，如图11（球面研磨磨过程示意图图）所示。注塑模模具钢的球面面研磨最优化参数目前前尚未在文献献得到确切的的依据。 步距步距研磨高度球磨研磨进给速度工作台图1 球面研磨磨过程示意图图进给研磨球工作台研磨深度研磨表面近年来 ，已经经进行

5、了一些些研究，确定了球面抛光工艺的最优参数(图2) （球面抛光过程示示意图）。 比如，人们们发现, 用用碳化钨球滚滚压的方法可可以使工件表表面的塑性变形减减少,从而改改善表面粗糙糙度、表面硬硬度、抗疲劳劳强度。 抛光光的工艺的过程是由加工中心心和车床共同完成成的。对表面面粗糙度有重重大影响的抛光工艺主要参数，主主要是球或滚滚子材料，抛光力， 进给速率,抛抛光速度,润润滑、抛光率率及其他因素素等。注塑模模具钢PDSS5的表面抛光的的参数优化，分别结合了油脂润滑剂剂，碳化钨球,抛光速度2200毫米/分钟,抛光光力300牛牛，40微米米的进给量。采采用最佳参数数进行表面研研磨和球面抛抛光的深度为为2

6、.5微米米。 通过抛光光工艺，表面粗粗糙度可以改善大致进给研磨球工作台研磨深度研磨表面 图2 球面抛抛光过程示意意图此项目研究的目目的是，发展注塑模具钢的球形研磨磨和球面抛光工工序，这种注塑模模具钢的曲面实在加工中心心完成的。表面光洁洁度的球研磨与球球抛光的自动化流程程工序，如图图3所示。 我们开始自自行设计和制制造的球面研研磨工具及加加工中心的对刀装置。利用田口正正交法，确定了表面面球研磨最佳佳参数。选择为田口L188型矩阵实验验相应的四个因素和和三个层次。 用最佳参数进进行表面球研研磨则适用于于一个曲面表表面光洁度要要求较高的注注塑模具。 为了改善表面粗粗糙, 利用用最佳球面抛光工艺参数，

7、再进行行对表层打磨磨。PDS试样的设计与制造PDS试样的设计与制造选择最佳矩阵实验因子确定最佳参数实施实验分析并确定最佳因子进行表面抛光应用最佳参数加工曲面测量试样的表面粗糙度球研磨和抛光装置的设计与制造图3自动球面研研磨与抛光工序的流程图二、球研磨的设设计和对准装装置实施过程中可能能出现的曲面面的球研磨,研研磨球的中心心应和加工中中心的Z轴相一致。 球球面研磨工具具的安装及调调整装置的设计，如图4（球面研磨工具及及其调整装置置）所示。电动磨床展展开了两个具有可调支撑撑螺丝的刀架。磨床中心正好好与具有辅助助作用的圆锥锥槽线配合。 拥有磨床床的球接轨,当两个可调支支撑螺丝被收收紧时，其后后的对准

8、部件件就可以拆除。研研磨球中心坐坐标偏差约为为5微米, 这是衡量一一个数控坐标标测量机性能能的重要标准准。 机床的机械振振动力是被螺旋弹簧所吸收。球形研磨球球和抛光工具的安安装，如图55（a. 球球面研磨工具具的图片. b.球抛光工工具的图片）所示。为使球面磨磨削加工和抛抛光加工的进进行，主轴通过球锁机制制而被锁定。 模柄模柄弹簧工具可调支撑紧固螺钉磨球自动研磨磨球组件图4 球面研磨磨工具及其调调整装置图5 a. 球球面研磨工具具的图片. b.球抛光工工具的图片三、矩阵实验的的规划3.1田口正交交表利用矩阵实验田田口正交法，可可以确定参数数的有影响程程度。 为了了配合上述球球面研磨参数数，该材

9、料磨料料的研磨球(直直径10毫米米),进给速速率，研磨深度,在次研究中中电气磨床被被假定为四个因因素，指定为从A到到D（见表11实验因素和和水平）。三个层次次的因素涵盖盖了不同的范范围特征,并用了数字11、2、3标标明。挑选三三类磨料,即即碳化硅,白白色氧化铝,粉红氧化铝铝来研究. 这三个数值的的大小取决于于每个因素实验验结果。选定定L18型正正交矩阵进行行实验，进而而研究四三级因素素的球形研磨磨过程。表1实验因素和和水平因素水平123A.碳化硅白色氧化铝粉红氧化铝B.50100200C.研磨深度（m）205080D.1200018000240003.2数据分析析的界定 工程设计问题,可以分为

10、较较小而好的类型,象征性最好好类型,大而而好类型，目标取向类型等。 信噪比(S/N)的比值，常作为目标标函数来优化产品或或者工艺设计。 被加工面的的表面粗糙度度值经过适当地组合磨削参参数，应小于原来来的未加工表面。 因此,球球面研磨过程程属于工程问问题中的小而好类型。这这里的信噪比比（S/N）,按按下列公式定定义: =10 log 平方等于质质量特性=10 loog （11）这里，y不同噪声声条件下所观察的质量特性n实验次数数从每个L18型型正交实验得得到的信噪比比（S/N）数据，经计算后，运用差异异分析技术(变异)和歼歼比检验来测测定每一个主要的的因素。 优化小而好好类型的工程程问题问题更更

11、是尽量使最大而定。各级选择择的最大化将对最最终的因素素有重大影响响。 最优条件件可视研磨球而待定。四、实验工作和和结果这项研究使用的的材料是PDDS5工具钢钢(相当于艾艾西塑胶模具具)， 它常用于大型注塑模模具产品在国国内汽车零件件领域和国内内设备。 该该材料的硬度度约HRC333(HS46)。 具体好处处之一是, 由于其特殊的热处处理前处理，模具可直接接用于未经进进一步加工工工序而对这一材料料进行加工。式样的设计计和制造,应应使它们可以安装装在底盘，来来测量相应的反反力。 PDDS5试样的的加工完毕后，装在大底盘盘上在三坐标加工中心心进行了铣削削，这种加工工中心是由钢钢铁公司所生生产(中压型

12、型三号),配配备了FANUCC-18M公公司的数控控制器器(0.999型)。用hommmelwerrket40000设备来来测量前机加工前表面的粗糙度,使其其可达到1.6微米。 图6试验验显示了球面磨磨削加工工艺艺的设置。 一个由RRenishhaw公司生生产的视频触触摸触发探头头，安装在加工工中心上，来来测量和确定和原始式式样的协调。 数控代码码所需要的磨磨球路径由PowerrMILL软软件产。这些代码经经过RS2322串口界面，可以传送到到装有控制器的的数控加工中中心上。加工中心加工中心数控机床电脑图6完成了L18型型矩阵实验后后，表2 （PDS5试试样光滑表层的粗糙度）总结了光滑表面的粗

13、糙度RAA值，计算了每一个个L18型矩阵阵实验的信噪噪比（S/NN）,从而用用于方程（1）。通过表22提供的各个个数值，可以以得到四种不同程度度因素的平均信信噪比（S/N），在图图7中已用图图表显示。表2 PDS55试样光滑表层的粗糙度实验序号ABCDS/N(dB)Mean111110.350.350.359.1190.350212220.370.360.388.6340.370313330.410.440.407.5970.417421230.630.650.643.8760.640522310.730.770.782.3800.760623120.450.420.397.5300.4207

14、31320.340.310.329.8010.323832130.270.250.2811.4710.267933210.320.320.329.8970.3201011220.350.390.408.3900.3801112330.410.500.436.9680.4471213110.400.390.427.8830.4031321130.330.340.319.7120.3271422210.480.500.476.3120.4831523320.570.610.534.8680.5701631310.590.550.545.0300.5601732120.360.360.358.954

15、0.3571833230.570.530.535.2930.543控制因素信噪比图7 控制影响响因素控制因素信噪比球面研磨工艺的的目标，就是是通过确定每每一种因子的的最佳优化程程度值，来使使试样光滑表表层的表面粗粗糙度值达到到最小。因为为 logg是一个减函函数，我们应应当使信噪比比（S/N）达达到最大。因因此，我们能能够确定每一一种因子的最最优程度使得得的值达到最最大。因此基基于这个点阵阵式实验的最最优转速应该该是180000RPM，如表3（优化组合球球面研磨参数数）所示。表3 优化组合合球面研磨参参数因素水平白色氧化铝50mm/min20m18000rpm从田口矩阵实验验获得的球面面研磨优

16、化参参数，适用于于曲面光滑的的模具，从而而改善表面的的粗糙度。选选择香水瓶为为一个测试载载体。对于被被测物体的模模具数控加工工中心，由PPowerMMILL软件件来模拟测试。经经过精铣，通通过使用从田田口矩阵实验验获得的球面面研磨优化参参数，模具表表面进一步光光滑。紧接着着,使用打磨抛光光的最佳参数数，来对光滑滑曲面进行抛抛光工艺，进进一步改善了了被测物体的的表面粗糙度度。(见图 9)。模具内部的表面粗粗糙度用hommeelwerkket40000设备来测测量。模具内部的表面粗粗糙度RA的的平均值为22.15微米米，光滑表面面粗糙度RA的的平均值为00.45微米米，抛光表面面粗糙度RA的的平均

17、值为00.07微米米。被测物体体的光滑表面面的粗糙度改改善了：(22.15-00.45)/2.15=79.1，抛光表面面的粗糙度改改善了：(22.15-00.07)/2.15=96.7。抛光表面抛光表面Ra=0.07m内部表面Ra=2.15m光滑表面Ra=0.45m图8 被测物体体表面粗糙度度五、结论在这项工作中,对注塑模具的的曲面进行了了自动球面研磨与球面面抛光加工，并并将其工艺最最佳参数成功功地运用到加工工中心上。 设计和制造造了球面研磨装置(及其对准组组件)。通过实施施田口L188型矩阵进行行实验，确定定了球面研磨磨的最佳参数数。对于PDDS5注塑模模具钢的最佳佳球面研磨参参数是以下一一

18、系列的组合合：材料的磨磨料为粉红氧化铝铝，进给量料5500毫米/分钟，磨削深度220微米，转转速为180000RPMM。通过使用用最佳球面研研磨参数，试试样的表面粗糙度度Ra值从约11.6微米提提高到0.335微米。应应用最优化表表面磨削参数数和最佳抛光光参数，来加加工模具的内内部光滑曲面面，可使模具具内部的光滑滑表面改善779.1，抛抛光表面改善善96.7。鸣谢作者感谢中国国国家科学理事会对本次研究究的支持, NSC 889-22112-E-0011-0559。Automatted suurfacee finiishingg of pplastiic injjectioon molld st

19、eeel with spherrical grindding aand baall buurnishhing pprocesssesAbstracctThis sttudy iinvesttigatees thee posssibiliities of auutomatted spphericcal grrindinng andd balll burnnishinng surrface finisshing proceesses in a freefform ssurfacce plaastic injecction mold steell PDS55 on aa CNC machiining

20、 centeer. Thhe dessign aand maanufaccture of a grindding ttool hholderr has been accommplishhed inn thiss studyy. The ooptimaal surrface grindding pparameeters were deterrminedd usinng Tagucchis orthoogonall arraay metthod ffor pllasticc injeectionn moldding ssteel PDS5 on a machiining centeer. Thhe

21、 opttimal surfaace grrindinng parrameteers foor thee plasstic iinjecttion mmold ssteel PDS5 were the ccombinnationn of aan abrrasivee mateerial of PAA Al2OO3, a grindding sspeed of 188 000 rpm, a griindingg deptth of 20 mm, andd a feeed off 50 mmm/minn. Thee surfface rroughnness RRa of the sspecimme

22、n caan be improoved ffrom aabout 1.60 m too 0.355 m bby usiing thhe opttimal parammeterss for surfaace grrindinng. Suurfacee rougghnesss Ra ccan bee furtther iimprovved frrom abbout 00.343 m too 0.066 m bby usiing thhe balll burrnishiing prrocesss withh the optimmal buurnishhing pparameeters. Applly

23、ing the ooptimaal surrface grindding aand buurnishhing pparameeters sequeentiallly too a fiine-miilled freefform ssurfacce molld inssert, the ssurfacce rouughnesss Ra of frreeforrm surrface regioon on the ttestedd partt can be immproveed froom aboout 2.15 mm to 00.07 m.Keywordds Autommated surfaace

24、fiinishiing Ball burniishingg proccess Grinnding proceess Surfaace rooughneess Tagucchis methood1 IntrooductiionPlasticcs aree impoortantt engiineeriing maateriaals duue to theirr speccific charaacteriisticss, succh as corroosion resisstancee, ressistannce too chemmicalss, loww denssity, and eease o

25、of mannufactture, and hhave iincreaasinglly repplacedd metaallic compoonentss in iindusttrial appliicatioons. IInjecttion mmoldinng is one oof thee impoortantt formming pprocessses ffor pllasticc prodducts. The surfaace fiinish qualiity off the plasttic innjectiion moold iss an eessenttial rrequirre

26、mentt due to itts dirrect eeffectts on the aappearrance of thhe plaastic produuct. FFinishhing pprocessses ssuch aas griindingg, pollishinng andd lappping aare coommonlly useed to improove thhe surrface finissh.The mouunted grindding ttools (wheeels) hhave bbeen wwidelyy usedd in coonventtionall mol

27、dd and die ffinishhing iindusttries. The geomeetric modell of mmounteed griindingg toolls forr autoomatedd surfface ffinishhing proceesses was iintrodduced in. AA finiishingg proccess mmode of spphericcal grrindinng toools foor auttomateed surrface finisshing systeems was ddevelooped iin. Grrindinng

28、 speeed, ddepth of cuut, feeed rate, and wheell proppertiees succh as abrassive mmateriial annd abrrasivee grainn sizee, aree the dominnant pparameeters for tthe spphericcal grrindinng proceess, aas shoown inn Fig. 1. TThe opptimall spheericall grinnding parammeterss for the iinjecttion mmold ssteel

29、 have not yyet beeen innvestiigatedd basedd in tthe liiteratture.Fig.1. Schemmatic diagrram off the spherrical grindding pprocesssIn receent yeears, some reseaarch hhas beeen caarriedd out in deetermiining the ooptimaal parrameteers off the ball burniishingg proccess (Fig. 2). For iinstannce, iit ha

30、ss beenn founnd thaat plaastic deforrmatioon on thhe worrkpiecce surrface can bbe redduced by ussing a tunngstenn carbbide bball oor a rrollerr, thuus impprovinng thee surfface roughhness, surfface hhardneess, aand faatiguee resiistancce. Thhe burniishingg proccess iis acccompliished by maachiniing

31、ceenterss and llathess. Thee mainn burnnishinng parrameteers haaving signiificannt effeccts onn the surfaace rooughneess arre balll or rolleer matteriall, burniishingg forcce, feeed raate, bburnisshing speedd, lubbricattion, and numbeer of burniishingg passses, aamong otherrs. Thhe opttimal surfaace

32、 burniishingg paraameterrs forr the plasttic innjectiion moold stteel PDS5 were a commbinattion oof greease llubriccant, the ttungstten caarbidee ball, a buurnishhing sspeed of 2000 mm/min, a burrnishiing foorce of 3000 N, and aa feedd of 440 m. Thhe deppth off peneetratiion off the burniished surfa

33、ace ussing tthe opptimall balll burnnishinng parrameteers was aabout 2.5 mmicronns. Thhe impprovemment oof thee surfface rroughnness throuugh buurnishhing pprocesss gennerallly rannged bbetweeen 40% and 990%.Fig. 2. Scheematicc diaggram oof thee balll-burnnishinng proocessThe aimm of tthis sstudy wa

34、s tto devvelop spherrical grindding aand ball burniishingg surfface ffinishh proccessess of aa freeeform surfaace plasttic innjectiion moold onn a maachiniing ceenter. The flowcchart of autommated surfaace fiinish usingg spheericall grinnding and bball bburnisshing proceesses is shhown iin Figg. 3.

35、We beegan bby dessigninng andd manuffacturring tthe spphericcal grrindinng toool andd its alignnment devicce for uuse onn a maachiniing ceenter. The optimmal suurfacee spheericall grindding pparameeters were deterrminedd by uutilizzing aa Taguuchiss orthoogonall arraay metthod. Four factoors annd th

36、rree coorresppondinng levells werre theen choosen ffor thhe Tagguchis L188 matrrix exxperimment. The ooptimaal mouunted spherrical grindding pparameeters for ssurfacce grindding wwere tthen aapplieed to the ssurfacce finnish oof a ffreefoorm surfaace caarrierr. To improove thhe surrface roughhness,

37、the grounnd surfaace waas furrther burniished, usinng thee optiimal bball bburnisshing parammeterss.Fig. 3. Floww chartt of aautomaated ssurfacce finnish uusing spherrical grindding aand baall buurnishhing pprocessses2 Desiggn of the sspheriical ggrindiing toool annd itss alignnment devicceTo carrry

38、 outt the possiible sspheriical ggrindiing prrocesss of aa freeeform surfaace, tthe ceenter of thhe balll griinder shoulld coiincidee withh the z-axiss of tthe maachiniing ceenter. The mountted spphericcal grrindinng tool and iits addjustmment ddevicee was desiggned, as shhown iin Figg. 4. The eelec

39、trric grrinderr was mountted inn a toool hoolder with two aadjusttable pivott screews. TThe ceenter of thhe griinder ball was wwell alignned wiith thhe hellp of the cconic groovve of the aalignmment ccomponnents. Havinng aliigned the ggrindeer balll, twwo adjjustabble piivot screwws werre tigghtenee

40、d; affter wwhich, the alignnment compoonentss couldd be rremoveed. Thhe devviatioon bettween the ccenterr coorrdinattes of thhe balll griinder and tthat oof thee shannk wass abouut 5 m, whichh was measuured bby a CCNC cooordinnate mmeasurring mmachinne. The fforce inducced byy the vibraation of thhe

41、 macchine bed iis abssorbedd by a heliccal sppring. The manuffacturred spphericcal grrindinng tool and bball-bburnisshing tool were mountted, aas shoown inn Fig. 5. Thhe spiindle was llockedd for both the sspheriical ggrindiing proceess annd thee balll burnnishinng proocess by a spinddle-loockingg m

42、echaanism.Fig.4. Schemmatic illusstratiion off the spherrical grindding ttool aand itts adjjustmeent devicceFig.5. (a) Photto of the sspheriical ggrindiing toool (b) Photoo of tthe baall buurnishhing ttool3 Plannning oof thee matrrix exxperimment3.1 Connfigurrationn of TTaguchhis ortthogonnal arrray

43、The efffects of seeverall paraameterrs cann be ddetermmined efficcientlly by coonductting mmatrixx expeerimennts ussing TTaguchhis oorthoggonal arrayy. To matchh the aforeementiioned spherrical grindding pparameeters, the aabrasiive maateriaal of the ggrindeer balll (wiith thhe diaameterr of 100 mm)

44、, the feed rate, the depthh of ggrindiing, aand thhe revollutionn of tthe ellectriic griinder were seleccted aas thee fourr expeerimenntal factoors (pparameeters) and desiggnatedd as ffactorr A too D (ssee Tablee 1) iin thiis ressearchh. Thrree leevels (setttings) for each factoor were confiiguredd

45、to ccover the rrange of innteresst, annd werre ideentifiied byy the digitts 1, 2, annd 3. Threee typees of abrassive mmateriials, namelly sillicon carbiide (SSiC), whitee alumminum oxidee (Al22O3, WA), and ppink aaluminnum oxxide (Al2O33, PA), werre sellectedd and studiied. TThree numerrical valuees

46、 of each factoor werre detterminned basedd on tthe prre-stuudy reesultss. Thee L18 orthoogonall arraay wass seleected to coonductt the matriix expperimeent foor fouur 3-llevel factoors of thhe sphhericaal griindingg proccess.Table1. The experrimenttal faactorss and theirr leveels3.2 Deffinitiion off

47、 the data analyysisEngineeering desiggn prooblemss can be diividedd intoo smalller-tthe betteer typess, nomminal-the-bbest ttypes, largger-thhe-bettter ttypes, signned-taarget typess, amoong otthers 8. The ssignall-to-nnoise (S/N) ratioo is uused aas thee objeectivee funcction for ooptimiizing a pro

48、oduct or proceess deesign. The surfaace rooughneess vaalue oof thee grouund suurfacee via aan adeequatee combbinatiion off grinnding parammeterss shouuld be smmallerr thann thatt of tthe orriginaal surrface. Conssequenntly, the spherrical grindding pprocesss is an exxamplee of aa smalller-tthe-beett

49、er type probllem. TThe S/N rattio, , is definned byy the folloowing equattion: =10 log100(mean squarre quaality charaacteriistic) =10 llog10where:yi : obbservaationss of tthe quualityy charracterristicc undeer diffferennt noiise condiitionss n: numbber off expeerimenntAfter tthe S/N rattio frrom thh

50、e expperimeental data of eaach L118 orthoogonall arraay is calcuulatedd, thee mainn effeect off eachh facttor was ddetermmined by ussing aan anaalysiss of vvariannce (AANOVA) techhniquee and aan F-rratio test. The optimmizatiion sttrateggy of the smalller-thhe bettter pprobleem is to maaximizze , as

51、 definned byy Eq. 1. Levells thaat maxximizee will be seelecteed forr the factoors thhat haave a siggnificcant eeffectt on . Thee optiimal ccondittions for sspheriical grindding ccan thhen bee deteermineed.4 Experrimenttal woork annd ressultsThe matteriall usedd in tthis sstudy was PPDS5 ttool sstee

52、l (equiivalennt to AIISI P220), wwhich is coommonlly useed forr the moldss of largee plasstic iinjecttion pproduccts inn the fieldd of aautomoobile compoonentss and ddomesttic apppliannces. The hhardneess off thiss mateerial is abbout HHRC33 (HS466). Onne speecificc advaantagee of tthis mmateriial i

53、s thhat affter mmachinning, the mmold ccan bee direectly used for ffurtheer finnishinng proocessees witthout heat treattment due tto itss speciial prre-treeatmennt. Thhe speecimenns werre dessignedd and manuffacturred so thhat thhey coould bbe mouunted on a dynammometeer to measuure thhe reaactionn

54、forcce. Thhe PDSS5 speecimenn was roughhly maachineed and tthen mmounteed on the ddynamoometerr to ccarry out tthe fine milliing onn a thhree-aaxis mmachinning ccenterr madee by YYang-IIron CCompanny (tyype MVV-3A), equiipped with a FUNNUC Coompanyy NC-coontrolller (type 0M). The ppre-maachineed sur

55、rface roughhness was mmeasurred, uusing Hommeelwerkke T40000 eqquipmeent, to bee abouut 1.6 m. Fiigure 6 shoows thhe expperimeental set-uup of the sspheriical ggrindiing prrocesss. A MMP10 ttouch-triggger probee madee by tthe Reenishaaw Commpany was aalso iintegrrated with the mmachinning ccenterr t

56、ooll magaazine to meeasuree and deterrmine the ccoordiinatedd origgin off the speciimen tto be grounnd. Thhe NC codess needded foor thee balll-burnnishinng patth werre gennerateed by PowerrMILL CAM ssoftwaare. TThese codess can be trransmiitted to the CCNC coontrolller oof thee machhiningg centter v

57、iia RS2232 seerial interrface.Fig.6. Experrimenttal seet-up to deetermiine thhe opttimal spherrical grindding pparameetersTable 22 summmarizees thee meassured grounnd surrface roughhness alue Ra and the ccalcullated S/N rratio of eaach L118 ortthogonnal arrray sing Eq. 11, aftter haaving execuuted t

58、the 188 matrrix exxperimments. The averaage S/N rattio foor eacch levvel off the four actorrs is shownn grapphicallly inn Fig. 7.Table2. Grouund suurfacee rougghnesss of PPDS5 sspecimmenExp.Inner array (control factors)Measured surface roughness value (Ra)ResponsenoABCDS/N(dB)Mean111110.350.350.359.

59、1190.350212220.370.360.388.6340.370313330.410.440.407.5970.417421230.630.650.643.8760.640522310.730.770.782.3800.760623120.450.420.397.5300.420731320.340.310.329.8010.323832130.270.250.2811.4710.267933210.320.320.329.8970.3201011220.350.390.408.3900.3801112330.410.500.436.9680.4471213110.400.390.427

60、.8830.4031321130.330.340.319.7120.3271422210.480.500.476.3120.4831523320.570.610.534.8680.5701631310.590.550.545.0300.5601732120.360.360.358.9540.3571833230.570.530.535.2930.543Fig.7. Plotss of ccontrool facctor eeffecttsThe goaal in the sspheriical ggrindiing prrocesss is tto minnimizee the surfaac