Lub hauv paus ntsiab lus sib tsoo thiab hnav mechanism ntawm kev sib tsoo lub log ntawm cov cuab yeej txiav

Lub hauv paus ntsiab lus sib tsoo thiab hnav mechanism ntawm kev sib tsoo lub log ntawm cov cuab yeej txiav.

 

1. Cov txheej txheem sib tsoo

Kev sib tsoo kuj yog ib hom kev txiav, thiab lub log sib tsoo tuaj yeem suav tias yog lub tshuab txiav milling nrog ntau me me txiav npoo thaum siv rau cov cuab yeej machining. Thaum lub sij hawm sib tsoo txheej txheem, cov cuab yeej nto yog raug kev sib txhuam thiab khawb los ntawm kev sib tsoo lub log, thiab cov khoom sib tsoo thiab cov ntse ntse abrasive ntawm lub log nto txiav rau hauv cov khoom, tsim cov chips. Cov txheej txheem sib tsoo yog qhov tseem ceeb ntawm kev txiav, khawb, thiab zawv zawg ua. Cov chips me me thiab sib txawv hauv cov duab, suav nrog ribbon-xws li cov chips, segmented chips, thiab qee cov chips melted thiab hlawv cov tshauv, nrog rau cov hmoov av hlau.

 

Kev sib tsoo tau muab faib ua peb theem: theem pib sib tsoo, theem ruaj khov, thiab theem tiav. Nyob rau hauv thawj theem sib tsoo, qhov sib tsoo qhov tob yog me dua li tus nqi noj radial. Qhov no yog vim lub elastic deformation ntawm lub tshuab cuab yeej, workpiece, thiab fixture system thaum lub sij hawm pib sib tsoo theem. Thaum lub kaw lus elastic deformation ncav cuag ib theem, nws nkag mus rau theem ruaj khov. Thaum noj txuas ntxiv, qhov sib tsoo qhov tob yog qhov tseem ceeb sib npaug rau tus nqi noj radial. Nyob rau hauv lub finishing theem, raws li lub elastic deformation ntawm cov txheej txheem yog maj tshem tawm, qhov tseeb sib tsoo qhov tob yuav ntau dua li xoom.

Kev sib tsoo nrog lub log sib tsoo muaj cov yam ntxwv hauv qab no: siab precision thiab qis nto roughness. Lub log sib tsoo muaj tus kheej -ntxhiab muaj nuj nqi, tso cai rau cov nplej abrasive txiav workpiece nrog cov npoo ntse. Lub radial quab yuam yog loj. Zoo ib yam li tig, txiav quab yuam thaum sib tsoo tuaj yeem decomposed rau hauv peb qhov sib koom ua ke, tab sis cov khoom siv radial quab yuam loj dua. Kev sib tsoo kub yog siab. Vim tias kev sib tsoo nrog lub log sib tsoo muaj qhov tsis zoo rake lub kaum sab xis txiav thiab txiav ceev heev, qhov sib tsoo kub yog siab. Lub log sib tsoo muaj tus kheej -ntxhiab nyhuv, tso cai rau cov nplej abrasive txuas ntxiv txiav cov khoom ua haujlwm nrog cov npoo ntse. Kev sib tsoo cov lus tsa suab muaj lub ntsiab lus, lub radial pub ceev, thiab axial pub ceev. Cov lus tsa suab tseem ceeb yog kev sib hloov ntawm kev sib tsoo lub log; lub linear tshaj tawm ntawm sab nraud ntawm lub sib tsoo log yog lub ntsiab lus ceev; radial pub tus nqi hais txog qhov kev ncua deb ntawm lub workpiece txav radially txheeb ze rau lub log sib tsoo thaum txhua ob (ib zaug) stroke ntawm lub rooj ua haujlwm; thiab axial pub tus nqi yog hais txog qhov kev ncua deb ntawm lub workpiece txav axially txheeb ze rau lub log sib tsoo thaum txhua lub kiv puag ncig lossis txhua qhov stroke ntawm lub rooj ua haujlwm.

 

2. Sib tsoo log hnav cov qauv thiab ua rau

Thaum lub sij hawm sib tsoo ntawm cov cuab yeej txiav, kev sib tsoo lub log yuav muaj kev sib txawv ntawm kev hnav vim muaj ntau yam, nrog rau lub cev, tshuaj lom neeg, thiab kev siv tshuab, ua rau muaj peev xwm sib tsoo thiab cuam tshuam rau qhov tseeb ntawm qhov helical zawj. Yog tias lub log sib tsoo hnyav hnyav tsis hloov thiab siv txuas ntxiv, nws yuav ua rau muaj kev vibrations, suab nrov, thiab lwm yam tshwm sim. Kev tshawb fawb dav dav ntawm kev sib tsoo log hnav tau pom tias cov ntaub ntawv tseem ceeb ntawm kev hnav yog abrasive hnav, tawg hnav, thiab txhaws / adhesion.

 

2.1 Abrasive Hnav

Thaum lub sij hawm kev sib tsoo, txhua lub pob zeb abrasive tau hnav, nthuav tawm ntau theem ntawm kev hnav ntsej muag, raws li pom hauv C-C dav hlau hauv daim duab hauv qab no. Raws li tus naj npawb ntawm blunted abrasive grains nce, lub sib tsoo log qhia blunting yam ntxwv, xws li ib tug tseem ceeb nce nyob rau hauv sib tsoo quab yuam, workpiece nto burning, thiab sib tham thaum lub sij hawm machining txheej txheem, ua rau ib tug loj poob rau hauv kev ua tau zoo ntawm cov machined qhov chaw.

2.2 Fracture thiab Hnav

Kev tawg thiab hnav ntawm kev sib tsoo log tuaj yeem muab faib ua ob hom: abrasive grain fracture thiab abrasive grain shedding. Abrasive grain fracture yog hais txog qhov tshwm sim uas, thaum qhov kev ntxhov siab ua rau ntawm cov nplej abrasive tshaj nws lub zog, ib feem ntawm cov nplej abrasive tawg tawm hauv daim ntawv me me. Abrasive grain shedding yog hais txog kev puas tsuaj ntawm cov hlua khi ntawm cov nplej abrasive, ua rau cov nplej abrasive tshem tawm ntawm lub log sib tsoo. Qhov no tsim voids qhov twg cov nplej detached nyob. Lub detachment ntawm fractured abrasive nplej los ntawm kev sib tsoo lub log ua rau tangential hnav ntawm lub workpiece, ua rau nws tsis tuaj yeem lav qhov tseeb qhov tseeb ntawm qhov. Txawm li cas los xij, kev tsim cov npoo tshiab los ntawm cov pob zeb uas tsis muaj pob zeb, cuam tshuam los ntawm cov pob zeb tawg thiab tawg, tuaj yeem txhais tau tias yog "tus kheej-sharpening" cuam tshuam ntawm lub log sib tsoo.

 

2.3 Clogging thiab Adhesion

Thaum lub sij hawm sib tsoo txheej txheem, vim qhov kub thiab txias siab, cov khoom siv ua haujlwm uas raug tshem tawm adheres rau cov nplej abrasive thaum lawv dhau los ntawm thaj chaw sib tsoo. Seb puas los yog tsis yog cov khoom adhered hu rau lub workpiece yog ib qho tseem ceeb ua rau abrasive grain puas thiab shedding. Kev sib tsoo muaj peev xwm kuj muaj feem xyuam rau cov khoom siv adhered. Cov khoom siv adhered tuaj yeem txhaws qhov khoob ntawm cov nplej abrasive. Kev txhaws hnyav kuj tuaj yeem ua rau cov pob txha tawg thiab txawm tias poob, txo qhov sib tsoo lub peev xwm sib tsoo.

 

Txhawm rau tshawb xyuas qhov xwm txheej ntawm kev sib tsoo log hnav, ntau tus kws tshawb fawb tau kawm txog qhov ua rau kev sib tsoo log hnav.

 

Tam sim no, cov laj thawj ntawm kev sib tsoo log hnav tau muab faib ua hom hauv qab no:

• Abrasive Hnav: Kev sib txhuam yog tsim los ntawm kev sib txheeb ntawm cov nplej abrasive thiab cov khoom ua haujlwm, ua rau cov khoom siv ntawm cov nplej abrasive. Qhov hnav no maj mam ua dhau lub sijhawm thaum kev sib tsoo zuj zus. Thaum sib tsoo, yog tias cov qauv ua haujlwm tsis sib xws thiab muaj cov ntsiab lus nyuaj nrog cov hardness siab dua, cov txheeb ze zawv zawg kev sib txhuam ntawm cov nplej abrasive thiab cov ntsiab lus nyuaj yuav ua rau cov neeg kho tshuab hnav ntawm cov nplej abrasive. Plastic Hnav: Thaum qhov sib tsoo kub nce mus txog ib theem, cov nplej abrasive yuav deform vim plasticity. Lub thermal hardness ntawm cov khoom siv ua haujlwm ncaj qha cuam tshuam rau cov yas hnav ntawm lub log sib tsoo. Raws li cov nplej abrasive hla dhau qhov chaw sib tsoo, lawv qhov kub thiab txias nce. Thaum nws ncav cuag lub melting point ntawm lub workpiece cov khoom, yog hais tias lub thermal hardness ntawm lub shear dav hlau yog ntau tshaj lub thermal hardness nyob rau hauv lub abrasive grain contact cheeb tsam, lub abrasive grains yuav undergo coj cov yas deformation nyob rau hauv lub contact cheeb tsam, ua rau abrasive hnav.
• Oxidative Hnav: Qee cov pa hauv huab cua tuaj yeem txhawb kev sib tsoo. Thaum cov txheej txheem sib tsoo tau ua tiav hauv lub tshuab nqus tsev, kev sib tsoo ntawm qis - carbon steel nrog alumina sib tsoo log tsis zoo li hauv huab cua. Kev soj ntsuam qhia tau hais tias qhov kev sib hloov ntawm lub log sib tsoo ua rau cov cua ntws, txo qhov kub ntawm qhov sib tsoo. Thaum qhov kub thiab txias, lub workpiece thiab chips raug oxidation, tsim cov oxide zaj duab xis rau ntawm qhov chaw, tiv thaiv cov nplaum hnav ntawm qhov chaw ua haujlwm.
• Chemical Hnav:Thaum lub sij hawm sib tsoo, qhov chaw ntawm lub log sib tsoo thiab qhov chaw ntawm lub workpiece nthuav tawm ib qho kev faib tawm ntawm qhov chaw. Kev sib tsoo ceev ceev ua rau muaj kev sib tsoo ntau dua, ua rau muaj tshuaj lom neeg ntawm cov khoom siv abrasive, cov khoom siv ua haujlwm, thiab cov kua dej sib tsoo. Cov tshuaj lom neeg ntau yam uas tsim los ntawm cov tshuaj tiv thaiv tshuaj no tuaj yeem dhau mus ntxiv ntau- theem tshuaj tiv thaiv. Cov tshuaj tiv thaiv ntawm cov khoom siv abrasive thiab cov khoom siv ua haujlwm yog ib qho tseem ceeb hauv kev siv tshuaj lom neeg ntawm kev sib tsoo.
• Diffusion Hnav:Thaum lub log sib tsoo lub workpiece, cov ntsiab lus ntawm qhov sib tsoo lub log thiab lub workpiece diffuse ntawm qhov kub thiab txias, ua rau cov txheej txheej ntawm cov nplej tsis muaj zog thiab ua rau hnav. Ob qho tib si sib cuag nrog cov ntaub ntawv hlau, nyob rau hauv qhov kub thiab txias, yuav raug diffusion nyob rau hauv qhov chaw sib cuag tom qab ib lub sij hawm sib tsoo, ua rau hnav ntawm cov sib tsoo log.
• Thermal Stress Fracture Hnav:Thaum lub sij hawm sib tsoo ntawm lub workpiece, cov nplej abrasive instantly ncav cuag qhov kub thiab txias sai sai nyob rau hauv qhov kev txiav txim ntawm cov kua sib tsoo. Nyob rau hauv kev sib txuas ua ke txias thiab cua sov, thermal stress nyob rau hauv cov nplej abrasive nce, ua rau tawg thiab tawg ntawm cov nplej abrasive. Thermal stress yog feem ntau cuam tshuam nrog thermal conductivity, coefficient ntawm thermal expansion, thiab sib tsoo kua. Thermal conductivity yog inversely proportional rau thermal stress, thaum lub coefficient ntawm thermal expansion yog ncaj qha proportional rau thermal stress. Qhov kev ua tau zoo ntawm cov dej sib tsoo zoo dua, qhov ua haujlwm ntawm qhov chaw ua haujlwm qis dua thiab qhov siab dua thermal stress.