Mastering For CMM Precision

Ambiri aCmm makina (kugwirizanitsa makina oyezera) amapangidwa ndizida za granite.

A Coordinate Measuring Machines (CMM) ndi chida choyezera chosinthika ndipo chapanga maudindo angapo ndi malo opangira, kuphatikiza kugwiritsidwa ntchito mu labotale yapamwamba, komanso gawo laposachedwa lothandizira mwachindunji kupanga pamalo opangira zinthu m'malo ovuta.Makhalidwe otentha a CMM encoder masikelo amakhala chinthu chofunikira kwambiri pakati pa maudindo ake ndikugwiritsa ntchito.

M'nkhani yomwe yasindikizidwa posachedwa, yolembedwa ndi Renishaw, nkhani ya njira zoyandama komanso luso lokwezera masikelo amakambidwa.

Masikelo a encoder amakhala odziyimira pawokha pawokhawokha (oyandama) kapena amadalira gawo lapansi (lokhazikika).Sikelo yoyandama imakula ndikumangika molingana ndi mawonekedwe a kutentha kwa sikelo, pomwe sikelo yokhazikika imakula ndikumangika pamlingo wofanana ndi gawo lapansi.Njira zoyezera sikelo zimapereka maubwino osiyanasiyana pamagwiritsidwe osiyanasiyana oyezera: nkhani yochokera ku Renishaw ikupereka nkhani yomwe sikelo yodziwika bwino ingakhale yankho labwino pamakina a labotale.

Ma CMM amagwiritsidwa ntchito kujambula data yoyezera magawo atatu molunjika kwambiri, zida zomangika, monga midadada ya injini ndi masamba a injini ya jet, monga gawo la njira yowongolera.Pali mitundu inayi yoyambira yamakina oyezera: mlatho, cantilever, gantry ndi mkono wopingasa.Ma CMM amtundu wa Bridge ndi omwe amapezeka kwambiri.Pamapangidwe a mlatho wa CMM, cholumikizira cha Z-axis chimayikidwa pangolo yomwe imayenda pamlathowo.Mlathowu umayendetsedwa motsatira njira ziwiri zowongolera ku Y-axis.Galimoto imayendetsa phewa limodzi la mlatho, pomwe phewa lakumanzere silimayendetsedwa: mawonekedwe a mlatho nthawi zambiri amawongoleredwa / kuthandizidwa ndi ma aerostatic bearings.Ngolo (X-axis) ndi quill (Z-axis) imatha kuyendetsedwa ndi lamba, screw kapena motor linear.Ma CMM adapangidwa kuti achepetse zolakwika zomwe sizingabwerezeke chifukwa izi ndizovuta kubweza kwa wowongolera.

Ma CMM ochita bwino kwambiri amakhala ndi bedi lalitali lotentha kwambiri la granite komanso mawonekedwe olimba a gantry / mlatho, wokhala ndi quill yotsika yomwe imamangiriridwa sensa kuti muyeze ntchito.Deta yopangidwa yomwe imagwiritsidwa ntchito kuwonetsetsa kuti magawo amakumana ndi zololera zomwe zidakonzedweratu.Ma encoder olondola kwambiri amayikidwa pamakina a X, Y ndi Z omwe amatha kutalika mamita ambiri pamakina akulu.

Mlatho wamtundu wa granite CMM umagwira ntchito m'chipinda chokhala ndi mpweya, kutentha kwapakati pa 20 ± 2 ° C, kumene kutentha kwa chipinda kumayenda katatu pa ola lililonse, kumalola kuti granite yotentha kwambiri ikhalebe kutentha kwapakati nthawi zonse. 20 °C.Chojambulira chachitsulo chosapanga dzimbiri choyandama chomwe chimayikidwa pa axis iliyonse ya CMM chingakhale chodziyimira pawokha pagawo la granite ndikuyankha mwachangu kusintha kwa kutentha kwa mpweya chifukwa cha kuchuluka kwamafuta komanso kutsika kwamafuta, komwe kumakhala kotsika kwambiri kuposa kuchuluka kwamafuta patebulo la granite. .Izi zitha kupangitsa kukula kwakukulu kapena kutsika kwa sikelo pamtunda wamba wa 3m wa pafupifupi 60 µm.Kukulaku kumatha kubweretsa vuto lalikulu la kuyeza komwe kumakhala kovuta kubweza chifukwa cha kusiyanasiyana kwa nthawi.

Chigawo chodziwika bwino cha gawo lapansi ndiye chisankho chomwe chimakonda pankhaniyi: sikelo yodziwika bwino imangokulirakulira ndi coefficient of thermal expansion (CTE) ya gawo lapansi la granite ndipo, chifukwa chake, iwonetsa kusintha pang'ono poyankha kutentha kwa mpweya.Kusintha kwa nthawi yayitali kwa kutentha kuyenera kuganiziridwabe ndipo izi zidzakhudza kutentha kwapakati pa kutentha kwakukulu kwa gawo lapansi.Kulipiridwa kwa kutentha ndikosavuta chifukwa wowongolera amangofunika kubweza momwe makinawo amatenthera popanda kuganiziranso za encoder scale matenthedwe.

Mwachidule, makina osindikizira okhala ndi masikelo odziwika bwino ndi njira yabwino yothetsera ma CMM okhala ndi CTE / matenthedwe otsika kwambiri komanso ntchito zina zomwe zimafunikira magwiridwe antchito apamwamba a metrology.Ubwino wa masikelo odziwika bwino ndi monga kufewetsa malamulo a chipukuta misozi ndi kuthekera kochepetsera zolakwika zoyesa zomwe sizingabwerezeke chifukwa, mwachitsanzo, kusiyanasiyana kwa kutentha kwa mpweya m'malo am'makina am'deralo.