Nto roughness yog qhov tseem ceeb rau feem ntau ntawm cov chaw cuam tshuam hauv kev sib cuag zawv zawg vim tias yam xws li thawj tus nqi hnav thiab nws cov xwm txheej tsis tu ncua yog nyob ntawm cov cuab yeej no. Cov chaw no feem ntau yog thauj khoom-cov kabmob thiab yuav tsum muaj cov cim roughness kom ntseeg tau tias tsim nyog rau lawv txoj kev siv.
Ntau cov khoom yuav tsum tau tshwj xeeb nto tiav kom ua tiav lawv cov haujlwm xav tau. Piv txwv muaj xws li cov phau ntawv journal bearings ntawm lub tsheb lub cev ua ntej pleev xim los yog ntawm lub crankshaft los yog camshaft.
[Duab]
Surface Roughness yog dab tsi?
Nto roughness, raws li peb feem ntau xa mus rau nws hauv kev ntsuas txhua hnub, tuaj yeem nkag siab tias qhov tsis sib xws ntawm qhov tsis sib xws thiab cov ncov me me thiab hav thaum lub sijhawm tsim khoom.
Nws feem ntau txhais tau tias yog feeb nrug (yav dhau los) ntawm ob lub ncov lossis ob lub hav. Feem ntau, lub wavelength yog nyob rau hauv 1 mm los yog tsawg dua. Nws kuj tseem tuaj yeem txhais tau tias yog kev ntsuas ntawm micro-profiles, feem ntau hu ua micro- qhov yuam kev qhov tseem ceeb.
Hauv cov ntsiab lus, tam sim no koj tuaj yeem muaj kev nkag siab dav dav ntawm roughness. Nqe lus hauv qab no muab kev txheeb xyuas ntxaws ntxiv.
Feem ntau, peb siv lub hauv paus los ntsuas qhov roughness. Qhov siab tshaj plaws saum lub hauv paus yog hu ua crest, thiab qhov qis tshaj plaws hauv qab lub hauv paus yog hu ua trough. Qhov siab ntawm lub crest thiab trough yog sawv cev los ntawm Z, thiab qhov sib nrug ntawm micro-texture ntawm cov khoom ua tiav yog sawv cev los ntawm S.
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Tus nqi ntawm S yog feem ntau txhais nyob rau hauv lub teb chaws pov thawj cov qauv raws li hauv qab no:
S <1 mm: Txhais raws li qhov roughness
1 Less tshaj los yog sib npaug S Less tshaj los yog sib npaug rau 10 mm: txhais raws li nto waviness
Suav teb cov qauv ntsuas ntsuas ntsuas tau teev tseg tias qhov roughness feem ntau yog ntsuas los ntawm peb qhov tsis muaj: VDA3400, Ra, thiab Rmax, nrog rau chav ntsuas ntsuas feem ntau qhia hauv μm.
Kev sib raug zoo ntawm cov kev ntsuas ntsuas
Ra yog txhais raws li qhov nruab nrab arithmetic sib txawv ntawm qhov nkhaus (nruab nrab roughness), Rz txhais raws li qhov nruab nrab qhov siab ntawm qhov tsis sib xws, thiab Ry txhais tias qhov siab tshaj plaws. Qhov siab tshaj plaws qhov sib txawv Ry ntawm micro-profile kuj yog sawv cev los ntawm Rmax hauv lwm cov qauv.
Thov xa mus rau cov lus hauv qab no rau kev sib raug zoo ntawm Ra thiab Rmax:
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Table: Sib piv ntawm Ra thiab Rmax parameters (µm)
Qhov saum npoo roughness tsim li cas?
Deg roughness yog tshwm sim los ntawm cov txheej txheem machining ntawm lub workpiece. Cov txheej txheem machining, cov khoom siv ua haujlwm, thiab cov txheej txheem tag nrho cuam tshuam qhov roughness.
Piv txwv li, thaum lub sij hawm hluav taws xob discharge machining (EDM), tawm pob tshwm nyob rau saum npoo ntawm lub tshuab machined.
Cov txheej txheem machining sib txawv thiab cov khoom siv ua haujlwm ua rau muaj ntau yam kab mob microscopic tshuav nyob rau saum npoo ntawm lub tshuab ua haujlwm, xws li qhov ntom, qhov tob, thiab cov duab sib txawv.
Qhov cuam tshuam ntawm Nto Roughness ntawm Workpieces
Workpiece hnav tsis kam, haum stability, qaug zog, corrosion kuj, sealing kev ua tau zoo, kev sib cuag nruj, ntsuas qhov tseeb, txheej, thermal conductivity thiab tiv thaiv, reflectivity thiab hluav taws xob zog, tsis kam ua kua thiab roj ntws, thiab tam sim no ntws ntawm tus neeg xyuas pib qhov chaw muaj ntau yam kev cuam tshuam.
Kev ntsuas ntsuas rau Nto Roughness
① Sampling Length: Chav tsev ntev ntawm txhua qhov ntsuas. Qhov ntsuas qhov ntev yog qhov ntev ntawm cov kab siv tau teev tseg rau kev ntsuas qhov roughness ntawm qhov chaw. Raws li ISO 1997 tus qauv, 0.08mm, 0.25mm, 0.8mm, 2.5mm, thiab 8mm feem ntau yog siv los ua qhov ntev.
② Kev Ntsuas Length: Muaj N siv ntev. Qhov saum npoo roughness ntawm qhov sib txawv ntawm ib feem tsis tuaj yeem raug sawv cev los ntawm ib qho kev siv ntev; Yog li ntawd, N sampling lengths yog xav tau los ntsuas qhov roughness saum npoo. Raws li ISO 1997 tus qauv, qhov ntsuas qhov ntev yog feem ntau N sib npaug rau 5.
③ Reference Line: Cov kab siv yog cov profile centerline siv los ntsuas qhov roughness tsis. Feem ntau, muaj tsawg kawg squares centerlines thiab profile arithmetic txhais tau tias centerlines.
[Least Squares Centerline] yog suav nrog qhov tsawg tshaj plaws squares txoj kev los ntawm cov ntsiab lus sau thaum ntsuas.
[Profile Arithmetic Mean Centerline] xyuas kom meej tias cov cheeb tsam ntawm ob qhov profile saum toj thiab hauv qab ntawm qhov nruab nrab yog sib npaug hauv qhov ntsuas qhov ntev.
Txoj kev xav, qhov tsawg tshaj plaws squares centerline yog qhov zoo tshaj plaws siv kab, tab sis nws yog ib qho nyuaj rau tau txais nyob rau hauv kev siv tswv yim. Yog li ntawd, qhov profile arithmetic txhais tau tias centerline feem ntau yog siv los hloov, thiab ib txoj kab ncaj nraim nrog rau qhov kwv yees yuav siv tau thaum ntsuas.
Qhov roughness tau txais li cas?
Kev ntsuam xyuas ntawm qhov roughness yog nce ntxiv hauv kev tsim khoom. Txhawm rau kawm qhov roughness ntawm qhov chaw, yuav tsum muaj lub tshuab tshwj xeeb: ntsuas qhov ntsuas qhov roughness. (Duab: Formtracer Avant series) Cov cuab yeej ntsuas qhov saum npoo av siv lub pob zeb diamond stylus rhiab heev los hla ntawm qhov chaw, zoo li lub phonograph khaws. Nws mam li cais qhov me me -wavelength roughness ntawm loj- nplai ripples thiab contours los ntawm lub wavelengths ntev dua- txheej txheem hu ua electronic filtering.
* Cov yam ntxwv ntawm stylus{0}} hom roughness ntsuas ntsuas tau txhais hauv ISO 3274: 1996.
(Duab: Schematic daim duab ntawm lub stylus{0}} hom nto roughness ntsuas ntsuas)
Txawm hais tias feem ntau qhov tseeb thiab ua tiav qhov kev ntsuas qhov roughness siv cov tshuab ntsuas tshwj xeeb, qee zaum, cov cuab yeej siv tau siv tau sai thiab qis dua - tus nqi ua haujlwm, raws li qhia hauv qab no:
Roughness piv daim hlau yog npib tsib xee-cov qauv ua los ntawm electroforming. Lawv zoo tagnrho rau kev ua haujlwm hlau thiab yog cov cuab yeej pabcuam zoo heev.
Tus neeg teb xov tooj tsuas yog khiav lawv cov ntiv tes hla txhua qhov chaw hauv ib lub teeb kom pom qhov ze tshaj plaws rau qhov chaw ua haujlwm tau muab piv. Qee tus neeg siv cov qauv no ua cov rooj saib, tab sis nws tseem ceeb heev uas yuav tsum nco ntsoov tias cov no tsis yog cov qauv siv. Roughness ntsuas tshuab muaj cov haujlwm sib txawv, siv cov kev ntsuas sib txawv, thiab sib txawv ntawm tus nqi. Ua ntej xaiv lub tshuab, nws raug nquahu kom sab laj nrog cov kws tshaj lij kev lag luam los xaiv cov qauv tsim nyog tshaj plaws raws li koj xav tau.
