Cov neeg uas koom nrog precision machining ntawm cov neeg kho tshuab qhov chaw paub tias txij thaum pib ntawm machining mus rau lub sij hawm ntawm machining, lub positioning datum yuav tsum tau xaiv. Yog li dab tsi yog qhov positioning reference?
Lub positioning datum yog siv los txiav txim qhov txheeb ze ntawm lub workpiece nrog rau qhov chaw ntawm lub tshuab thiab cov cuab yeej. Cov ntaub ntawv siv thaum pib yog unprocessed thiab hu ua coarse data. Qhov chaw datum siv nyob rau hauv cov txheej txheem tom ntej yog machined nto, uas peb hu ua fine datum.
Nyob rau hauv cov txheej txheem machining tsim ntawm txhua yam khoom, yuav ua li cas xaiv raws li ib tug datum nto yog ib qho tseem ceeb heev teeb meem; seb qhov kev xaiv ntawm qhov chaw datum yog qhov tsim nyog yuav cuam tshuam ncaj qha rau kev ua haujlwm zoo ntawm precision qhov chaw thiab qhov nyuaj ntawm lub tshuab cuab yeej fixture qauv. Lub luag hauj lwm ntawm lub boutique benchmark yog txawv, cov kev xaiv ntawm ob qho tib si kuj txawv.
Rough benchmark xaiv cov hauv paus ntsiab lus: ib tug yog los xyuas kom meej tias txhua machined nto muaj txaus margin, qhov thib ob yog los xyuas kom meej tias qhov luaj li cas thiab qhov chaw ntawm unmachined nto nyob rau hauv txoj kab nrog rau daim duab yuav tsum tau. Cov xaiv coarse datum yuav tsum yooj yim rau txoj hauj lwm, clamping thiab ua, kom lub fixture qauv yog yooj yim. Yog tias koj xyuas kom meej tias lub workpiece tau raug machined nto thiab txoj hauj lwm ntawm lub unmachined nto yog tseeb, lub unmachined nto yuav tsum tau siv raws li ib tug ntxhib siv. Txhawm rau kom ntseeg tau tias qhov nyiaj roughing ntawm qhov tseem ceeb ntawm qhov chaw me me thiab sib xws, qhov saum npoo yuav tsum raug xaiv raws li qhov roughing datum. Txhawm rau kom ntseeg tau tias qhov nyiaj roughing ntawm qhov tseem ceeb ntawm qhov chaw me me thiab sib xws, qhov saum npoo yuav tsum raug xaiv raws li qhov roughing datum. Nyob rau hauv thiaj li yuav ua rau lub machining pub ntawm ntau precision machining nto ntawm lub dawb paug ntau yam, lub ntxhib machining nto yuav tsum tau xaiv kom cov ntxhib machining nto yog raws li cov xaiv ntxhib machining datum. Ib tug ntxhib datum nto nrog uniform positional yuam kev yog ib tug ntxhib datum nto. Qhov ntxhib datum nto yuav tsum tiaj tus, tsis muaj qhov tsis xws luag xws li sprue, riser lossis ya ntug, kom ntseeg tau qhov chaw ruaj ntseg. General ntxhib datum tsuas yog siv tau ib zaug xwb, tshwj xeeb tshaj yog qhov tseem ceeb ntawm qhov chaw datum, thiaj li tsis ua qhov yuam kev loj.
Mechanical qhov chaw machining qhov tseeb benchmark xaiv txoj cai: qhov xaiv qhov chaw benchmark yuav tsum yooj yim mus nrhiav, clamping thiab ua, thiab yuav tsum muaj txaus positioning raug. Uniform benchmark txoj cai. Thaum lub workpiece yog positioned nrog ib tug tej pab pawg neeg ntawm zoo datum los pab txhawb kev ua ntawm feem ntau ntawm cov seem seem, tib pab pawg neeg ntawm datum yuav tsum tau siv rau positioning nyob rau hauv cov txheej txheem ntawm cov nto, uas yuav txo tau tus tsim thiab siv cov cuab yeej thiab zam txim. Kev hloov pauv yuam kev thiab nce kev tsim khoom. Reference overlap txoj cai. Thaum lub machined nto ntawm ib tug precision mechanical ib feem yuav tsum tau los xyuas kom meej qhov positional raug ntawm qhov kawg, tus tsim siv yuav tsum tau xaiv raws li qhov chaw siv. Thaum siv cov ntaub ntawv siv tau zoo ib yam rau qhov chaw thiab qhov tseeb ntawm qhov chaw ntawm cov chaw no tsis tuaj yeem lav tau, kev siv sib tshooj yuav tsum tau siv. Lub hauv paus ntsiab lus yog lub hauv paus ntsiab lus ntawm tus kheej. Thaum qee qhov txheej txheem txheej txheej saum npoo yuav tsum muaj cov npoo me me thiab tsis sib xws, lub tshuab nto nws tus kheej tuaj yeem siv los ua qhov kev siv rau qhov chaw, thaum txoj hauj lwm qhov yuav tsum tau ua kom ntseeg tau los ntawm cov txheej txheem ua ntej.