Uyini umshini wokulinganisa ohlanganisayo?

Aumshini wokulinganisa ohlanganisayo(CMM) iyithuluzi elilinganisa i-geometry yezinto ezibonakalayo ngokuzwa amaphuzu ahlukene ebusweni bento nge-probe. Izinhlobo ezahlukene zama-probe zisetshenziswa kuma-CMM, kufaka phakathi ukukhanya kwe-mechanical, optical, laser, kanye nokukhanya okumhlophe. Kuye ngomshini, indawo ye-probe ingalawulwa ngesandla ngumsebenzisi noma ingalawulwa yikhompyutha. Ama-CMM ngokuvamile acacisa indawo ye-probe ngokuya ngokufuduka kwayo kusuka endaweni yokubhekisela ohlelweni lwe-Cartesian coordinate olunezinhlangothi ezintathu (okungukuthi, ngama-axes e-XYZ). Ngaphezu kokuhambisa i-probe kuma-axes e-X, Y, kanye ne-Z, imishini eminingi ivumela ne-engeli ye-probe ukuthi ilawulwe ukuze kuvunyelwe ukukalwa kwezindawo ebezingenakufinyeleleka ngaphandle kwalokho.

I-CMM ejwayelekile ye-3D “yebhuloho” ivumela ukunyakaza kweprobe ngemigqa emithathu, u-X, u-Y no-Z, okuyi-orthogonal komunye nomunye ohlelweni lwe-Cartesian coordinate olunezinhlangothi ezintathu. I-axis ngayinye ine-sensor eqapha indawo yeprobe kuleyo axis, ngokuvamile ngokunemba kwe-micrometer. Lapho i-probe ixhumana (noma ithola ngenye indlela) indawo ethile entweni, umshini uhlola izinzwa ezintathu zesikhundla, ngaleyo ndlela ulinganisa indawo yephuzu elilodwa ebusweni bento, kanye ne-vector enezinhlangothi ezintathu yesilinganiso esithathiwe. Le nqubo iphindaphindwa uma kudingeka, ihambisa i-probe isikhathi ngasinye, ukuze kukhiqizwe “ifu lephuzu” elichaza izindawo zobuso ezithakaselwayo.

Ukusetshenziswa okuvamile kwama-CMM kusezinqubweni zokukhiqiza nokuhlanganisa ukuhlola ingxenye noma ukuhlanganisa ngokumelene nenhloso yokuklama. Kulezo zinhlelo zokusebenza, kukhiqizwa amafu amaphoyinti ahlaziywa ngama-algorithms okubuyela emuva ekwakheni izici. Lawa maphuzu aqoqwa ngokusebenzisa i-probe ebekwe ngesandla ngumsebenzisi noma ngokuzenzakalelayo nge-Direct Computer Control (DCC). Ama-CMM e-DCC angahlelwa ukuze alinganise izingxenye ezifanayo ngokuphindaphindiwe; ngakho-ke i-CMM ezenzakalelayo iwuhlobo olukhethekile lwerobhothi lezimboni.

Izingxenye

Imishini yokulinganisa ehlanganisa izinto ihlanganisa izingxenye ezintathu eziyinhloko:

• Isakhiwo esiyinhloko esihlanganisa ama-axis amathathu okunyakaza. Izinto ezisetshenziswa ukwakha uhlaka oluhambayo ziye zahlukahluka eminyakeni edlule. I-Granite nensimbi kwakusetshenziswa kuma-CMM okuqala. Namuhla bonke abakhiqizi abakhulu be-CMM bakha amafreyimu nge-aluminium alloy noma okunye okuphumayo futhi basebenzisa i-ceramic ukwandisa ukuqina kwe-axis ye-Z ukuze kusetshenziswe ukuskena. Bambalwa abakhi be-CMM namuhla abasakhiqiza uhlaka lwe-granite CMM ngenxa yesidingo semakethe sokuthuthuka kwe-metrology kanye nomkhuba okhulayo wokufaka i-CMM ngaphandle kwelebhu yekhwalithi. Ngokuvamile abakhi be-CMM abaphansi kuphela kanye nabakhiqizi basekhaya eShayina naseNdiya abasakhiqiza i-granite CMM ngenxa yendlela yobuchwepheshe obuphansi kanye nokungena okulula ukuze babe umakhi wohlaka lwe-CMM. Umkhuba okhulayo wokuskena udinga futhi i-axis ye-CMM Z ukuthi iqine futhi izinto ezintsha zethulwe njenge-ceramic ne-silicon carbide.
• Uhlelo lokuhlola
• Uhlelo lokuqoqwa kwedatha nokunciphisa — ngokuvamile luhlanganisa isilawuli somshini, ikhompyutha yedeskithophu kanye nesofthiwe yohlelo lokusebenza.

Ukutholakala

Le mishini ingaba ekhululekile, ephathwa ngesandla futhi ephathwayo.

Ukunemba

Ukunemba kwemishini yokulinganisa ehlanganisiwe kuvame ukunikezwa njengento engaqiniseki njengomsebenzi ongaphezu kwebanga. Ku-CMM esebenzisa i-touch probe, lokhu kuhlobene nokuphindaphinda kwe-probe kanye nokunemba kwezikali eziqondile. Ukuphindaphinda okuvamile kwe-probe kungabangela ukulinganiswa okungaphakathi kwe-.001mm noma i-.00005 intshi (ingxenye yeshumi) phezu kwevolumu yonke yokulinganisa. Kumishini engu-3, ​​3+2, kanye ne-5 axis, ama-probe alinganiswa njalo kusetshenziswa amazinga okulandelela futhi ukunyakaza komshini kuqinisekiswa kusetshenziswa ama-gauge ukuqinisekisa ukunemba.

Izingxenye ezithile

Umzimba womshini

I-CMM yokuqala yathuthukiswa yiFerranti Company yaseScotland ngawo-1950 ngenxa yesidingo esiqondile sokulinganisa izingxenye ezinembile emikhiqizweni yabo yezempi, yize lo mshini wawunezingqimba ezimbili kuphela. Amamodeli okuqala angama-axis amathathu aqala ukuvela ngawo-1960 (i-DEA yase-Italy) futhi ukulawulwa kwekhompyutha kwaqala ekuqaleni kwawo-1970 kodwa i-CMM yokuqala esebenzayo yathuthukiswa futhi yathengiswa yiBrowne & Sharpe eMelbourne, eNgilandi. (ILeitz Germany kamuva yakhiqiza isakhiwo somshini esiqinile esinetafula elihambayo.

Emishinini yesimanje, isakhiwo esingaphezulu sohlobo lwe-gantry sinemilenze emibili futhi sivame ukubizwa ngokuthi ibhuloho. Lokhu kuhamba ngokukhululeka etafuleni le-granite ngomlenze owodwa (ovame ukubizwa ngokuthi umlenze wangaphakathi) kulandela isitimela esiqondisayo esinamathiselwe kolunye uhlangothi lwetafula le-granite. Umlenze ophambene (ngokuvamile umlenze wangaphandle) umane uphumule etafuleni le-granite kulandela ukwakheka kobuso obuqondile. Ama-air bearings ayindlela ekhethiwe yokuqinisekisa ukuhamba okungenazingxabano. Kulawa, umoya ocindezelwe uphoqeleka ukudlula ochungechungeni lwezimbobo ezincane kakhulu endaweni eyisicaba yokuthwala ukuze kuhlinzekwe ngomcamelo womoya obushelelezi kodwa olawulwayo lapho i-CMM ingahamba khona ngendlela ecishe ingabi nezingxabano engakhokhelwa ngesofthiwe. Ukuhamba kwebhuloho noma i-gantry etafuleni le-granite kwakha i-axis eyodwa yendiza ye-XY. Ibhuloho le-gantry liqukethe inqola edlula phakathi kwemilenze yangaphakathi neyangaphandle bese yakha enye i-axis evundlile ye-X noma ye-Y. I-axis yesithathu yokunyakaza (i-axis ye-Z) inikezwa ngokwengeza i-quill eqondile noma i-spindle ehamba phezulu naphansi phakathi kwenqola. I-touch probe yakha idivayisi yokuzwa ekugcineni kwe-quill. Ukunyakaza kwama-axis e-X, Y kanye ne-Z kuchaza ngokugcwele imvilophu yokulinganisa. Amatafula ajikelezayo angakhethwa angasetshenziswa ukuthuthukisa ukufinyeleleka kweprobe yokulinganisa ezintweni zokusebenza eziyinkimbinkimbi. Ithebula elijikelezayo njenge-axis yedrayivu yesine alithuthukisi ubukhulu bokulinganisa, obuhlala buyi-3D, kodwa linikeza izinga lokuguquguquka. Amanye ama-touch probe ngokwawo angamadivayisi ajikelezayo asebenza ngamandla ane-probe tip ekwazi ukujika ngokuqondile ngaphezu kwama-degrees angu-180 kanye nokujikeleza okugcwele kwama-degrees angu-360.

Ama-CMM manje aseyatholakala nangezinye izindlela ezahlukene. Lokhu kufaka phakathi izingalo ze-CMM ezisebenzisa izilinganiso ze-angular ezithathwe emajoyintini engalo ukuze kubalwe indawo yesihloko se-stylus, futhi zingafakwa ama-probe okuskena nge-laser kanye ne-optical imaging. Ama-CMM anga anjalo avame ukusetshenziswa lapho ukuphatheka kwawo kuyinzuzo ngaphezu kwama-CMM ebhedi aqinile endabuko - ngokugcina izindawo ezilinganisiwe, isofthiwe yokuhlela iphinde ivumele ukuhambisa ingalo yokulinganisa ngokwayo, kanye nomthamo wayo wokulinganisa, nxazonke kwengxenye ezolinganiswa ngesikhathi sokulinganisa. Ngenxa yokuthi izingalo ze-CMM zilingisa ukuguquguquka kwengalo yomuntu, zivame futhi ukufinyelela ngaphakathi kwezingxenye eziyinkimbinkimbi ezazingenakuphenywa kusetshenziswa umshini ojwayelekile we-three axis.

I-probe yemishini

Ezinsukwini zokuqala zokulinganisa (i-CMM), ama-probe omshini ayefakwa esibambini esikhethekile ekugcineni kwe-quill. I-probe evame kakhulu yenziwa ngokuhlanganisa ibhola eliqinile ekugcineni kwe-shaft. Lokhu kwakufanelekile ekulinganiseni ububanzi obuphelele bobuso obuyisicaba, obuyindilinga noma obuyindilinga. Amanye ama-probe ayegaywa abe yizimo ezithile, isibonelo i-quadrant, ukuze kuvunyelwe ukulinganisa izici ezikhethekile. Lawa ma-probe ayebanjwe ngokomzimba ngokumelene nomsebenzi lapho isikhundla esikhaleni sifundwa kusuka ku-3-axis digital readout (DRO) noma, ezinhlelweni ezithuthuke kakhulu, angena kukhompyutha nge-footswitch noma idivayisi efanayo. Ukulinganisa okuthathwa yile ndlela yokuxhumana kwakuvame ukungathembeki njengoba imishini yayihanjiswa ngesandla futhi umqhubi womshini ngamunye wasebenzisa inani elihlukile lokucindezela ku-probe noma wasebenzisa amasu ahlukene okulinganisa.

Okunye okuthuthukisiwe kwaba ukwengezwa kwezinjini zokushayela i-axis ngayinye. Abaqhubi babengasadingeki ukuthinta umshini ngokomzimba kodwa babekwazi ukushayela i-axis ngayinye besebenzisa ibhokisi lesandla elinama-joystick ngendlela efanayo nezimoto zanamuhla ezilawulwa kude. Ukunemba kokulinganisa nokunemba kwathuthuka kakhulu ngokusungulwa kwe-probe ye-touch trigger ye-elekthronikhi. Iphayona lale divayisi entsha ye-probe kwakunguDavid McMurtry owabe esesungula lokho manje okuyiRenishaw plc. Nakuba kwakusalokhu kuyidivayisi yokuxhumana, i-probe yayine-stylus yensimbi enesipilingi (kamuva eyaba yi-ruby ball). Njengoba i-probe ithinta ubuso bengxenye, i-stylus yaphambuka futhi yathumela ngesikhathi esifanayo ulwazi lwe-X,Y,Z kukhompyutha. Amaphutha okulinganisa abangelwa abaqhubi ngabanye aba mancane futhi kwabekwa isiteji sokwethulwa kwemisebenzi ye-CNC kanye nokukhula kwama-CMM.

Ama-optical probe ayizinhlelo ze-lens-CCD, ezinyakaziswa njengezikamashini, futhi ziqondiswe endaweni ethakazelisayo, esikhundleni sokuthinta izinto. Isithombe esithathwe sobuso sizovalwa emingceleni yefasitela lokulinganisa, kuze kube yilapho insalela yanele ukuqhathanisa phakathi kwezindawo ezimnyama nezimhlophe. Ijika elihlukanisayo lingabalwa kuze kube iphuzu, okuyiphuzu lokulinganisa elifunwayo esikhaleni. Ulwazi oluvundlile ku-CCD luyi-2D (XY) kanti indawo eqondile yindawo yesistimu yokuhlola ephelele ku-stand Z-drive (noma enye ingxenye yedivayisi).

Izinhlelo zokuhlola ukuskena

Kunezinhlobo ezintsha ezinama-probe ahudula ebusweni bengxenye ethatha amaphuzu ngezikhathi ezithile, ezaziwa ngokuthi ama-scanning probe. Le ndlela yokuhlola i-CMM ivame ukuba nembe kakhulu kunendlela evamile yokuthinta futhi ishesha kakhulu.

Isizukulwane esilandelayo sokuskena, esaziwa ngokuthi ukuskena okungathintani, okuhlanganisa i-laser ene-point triangulation ye-laser esheshayo, ukuskena kwe-laser line, kanye nokuskena kokukhanya okumhlophe, kuthuthuka ngokushesha okukhulu. Le ndlela isebenzisa imisebe ye-laser noma ukukhanya okumhlophe okuvezwe ebusweni bengxenye. Izinkulungwane eziningi zamaphuzu zingathathwa futhi zisetshenziswe hhayi nje ukuhlola usayizi nendawo, kodwa nokudala isithombe se-3D sengxenye. Le "datha ye-point-cloud" ingabe isidluliselwa kusofthiwe ye-CAD ukuze kudalwe imodeli ye-3D esebenzayo yengxenye. Lawa ma-optical scanner avame ukusetshenziswa ezingxenyeni ezithambile noma ezithambile noma ukwenza lula ubunjiniyela obubuyela emuva.

Ama-probe e-Micrometrology

Izinhlelo zokuhlola zezinhlelo zokusebenza ze-metrology ye-microscale zingenye indawo evelayo. Kunemishini eminingi yokulinganisa etholakala kwezentengiselwano (i-CMM) ene-microprobe ehlanganiswe ohlelweni, izinhlelo eziningana ezikhethekile emalabhorethri kahulumeni, kanye nanoma yiziphi izinkundla ze-metrology ezakhiwe eyunivesithi ze-metrology ye-microscale. Nakuba le mishini mihle futhi ezimweni eziningi izinkundla ze-metrology ezinhle kakhulu ezinezikali ze-nanometric, umkhawulo wazo oyinhloko i-micro/nano probe ethembekile, eqinile, nekwaziyo.^{[kudingeka ingcaphuno]}Izinselele zobuchwepheshe bokuhlola nge-microscale zifaka phakathi isidingo se-probe ye-aspect ratio ephezulu enikeza ikhono lokufinyelela izici ezijulile nezincane ezinamandla okuxhumana aphansi ukuze kungalimazi ubuso kanye nokunemba okuphezulu (izinga le-nanometer).^{[kudingeka ingcaphuno]}Ngaphezu kwalokho, ama-probe e-microscale asengozini yezimo zemvelo ezifana nomswakama kanye nokusebenzisana kwendawo efana nokunamathela (okubangelwa ukunamathela, i-meniscus, kanye/noma amandla e-Van der Waals phakathi kwezinye).^{[kudingeka ingcaphuno]}

Ubuchwepheshe bokufeza ukuhlolwa kwe-microscale buhlanganisa inguqulo encishisiwe yama-probe e-CMM akudala, ama-probe e-optical, kanye ne-probe yamagagasi amile phakathi kokunye. Kodwa-ke, ubuchwepheshe bamanje be-optical abukwazi ukukalwa buncane ngokwanele ukukala isici esijulile nesincane, futhi isixazululo se-optical sinqunyelwe ubude bokukhanya. Ukuthwebula izithombe nge-X-ray kunikeza isithombe sesici kodwa akukho lwazi lwe-metrology olulandelekayo.

Izimiso zomzimba

Ama-optical probe kanye/noma ama-laser probe angasetshenziswa (uma kungenzeka ngokuhlanganiswa), ashintsha ama-CMM abe ama-microscope okulinganisa noma imishini yokulinganisa enezinzwa eziningi. Izinhlelo ze-Fringe projection, izinhlelo ze-theodolite triangulation noma izinhlelo ze-laser distant kanye ne-triangulation azibizwa ngokuthi imishini yokulinganisa, kodwa umphumela wokulinganisa uyafana: iphuzu lesikhala. Ama-Laser probe asetshenziselwa ukuthola ibanga phakathi kobuso kanye nephuzu lokubhekisela ekugcineni kwe-kinematic chain (okungukuthi: ukuphela kwengxenye ye-Z-drive). Lokhu kungasebenzisa umsebenzi we-interferometrical, ukuhlukahluka kokugxila, ukuphambuka kokukhanya noma isimiso somthunzi we-beam.

Imishini yokulinganisa ama-coordinate ephathekayo

Nakuba ama-CMM endabuko esebenzisa i-probe ehamba ngezimbazo ezintathu ze-Cartesian ukuze ilinganise izici zomzimba zento, ama-CMM aphathekayo asebenzisa izingalo ezihlanganisiwe noma, uma kwenzeka ama-CMM abonakalayo, izinhlelo zokuskena ezingenazo izingalo ezisebenzisa izindlela ze-optical triangulation futhi zivumela inkululeko ephelele yokuhamba nxazonke kwento.

Ama-CMM aphathekayo anezingalo ezihlanganisiwe anezingqimba eziyisithupha noma eziyisikhombisa ezifakwe ama-encoder ajikelezayo, esikhundleni sezingqimba eziqondile. Izingalo eziphathekayo zilula (ngokuvamile zingaphansi kwamakhilogremu angu-20) futhi zingathwalwa futhi zisetshenziswe cishe noma kuphi. Kodwa-ke, ama-CMM abonakalayo asetshenziswa kabanzi embonini. Aklanywe ngamakhamera aqondile noma ama-matrix array (njengeMicrosoft Kinect), ama-CMM abonakalayo mancane kune-CMM aphathekayo anezingalo, awanazintambo, futhi avumela abasebenzisi ukuthi bathathe kalula izilinganiso ze-3D zazo zonke izinhlobo zezinto ezitholakala cishe noma kuphi.

Ezinye izinhlelo zokusebenza ezingaphindaphindi njengobunjiniyela obubuyela emuva, i-prototyping esheshayo, kanye nokuhlolwa okukhulu kwezingxenye zabo bonke osayizi kufaneleka kakhulu kuma-CMM aphathekayo. Izinzuzo zama-CMM aphathekayo ziningi. Abasebenzisi banokuguquguquka ekuthatheni izilinganiso ze-3D zazo zonke izinhlobo zezingxenye nasezindaweni ezikude kakhulu/ezinzima. Kulula ukuzisebenzisa futhi azidingi indawo elawulwayo ukuze zithathe izilinganiso ezinembile. Ngaphezu kwalokho, ama-CMM aphathekayo avame ukubiza kancane kune-CMM yendabuko.

Ukushintshana okungokwemvelo kwama-CMM aphathekayo kuwukusebenza ngesandla (ahlala edinga umuntu ukuze awasebenzise). Ngaphezu kwalokho, ukunemba kwawo okuphelele kungaba okunembe kancane kunokwe-CMM yohlobo lwebhuloho futhi akufaneleki kwezinye izinhlelo zokusebenza.

Imishini yokulinganisa izinzwa eziningi

Ubuchwepheshe bendabuko be-CMM obusebenzisa ama-touch probe namuhla buvame ukuhlanganiswa nobunye ubuchwepheshe bokulinganisa. Lokhu kufaka phakathi izinzwa ze-laser, zevidiyo noma zokukhanya okumhlophe ukuze kuhlinzekwe lokho okwaziwa ngokuthi ukulinganisa ama-multisensor.