I. Hom Xov
Cov xov tau muab faib ua ob pawg loj raws li lawv lub hom phiaj: txuas cov xov thiab xa xov.
1. Txuas xov
Kev sib txuas xov yog muab faib ua ob hom: cov xov zoo tib yam thiab cov yeeb nkab xov, feem ntau yog siv rau kev sib txuas. Muaj plaub txoj xov uas feem ntau siv, xws li: ntxhib- suab zoo tib yam xov, zoo- suab zoo tib yam xov, yeeb nkab xov, thiab cov yeeb nkab tapered.
① Daim ntawv xov ntawm cov xov zoo tib yam yog daim duab peb sab sib npaug (xov lub kaum sab xis yog 60 degree). Qhov sib txawv ntawm qhov zoo - suab thiab ntxhib - suab xov yog tias nyob rau hauv tib txoj kab uas hla loj, lub suab ntawm nplua - suab xov yog me dua li ntawm ntxhib - suab xov.
② Cov ntaub ntawv ntawm cov yeeb nkab threads thiab tapered yeeb nkab threads yog daim duab peb sab isosceles (xov lub kaum sab xis yog 55 degree). Cov yeeb nkab xov yog tsuas yog siv rau kev sib txuas ntawm cov kav dej, cov kav dej roj, cov kav dej thiab lwm cov kav dej. Cov yeeb nkab xov yog muab faib ua cylindrical yeeb nkab threads thiab tapered yeeb nkab threads, ob leeg yog nyob rau hauv nti, thiab lub suab yog qhia los ntawm cov xov tooj ntawm threads nyob rau hauv ib tug 25.4mm xov ntev.
Cov yeeb nkab xov txuas ntxiv tau muab faib ua:
● Tsis yog- kaw cov yeeb nkab threads (G): Cov yeeb nkab xov kais yog siv rau kev ua xov sab hauv, thiab cov tuag yog siv rau kev ua cov xov sab nraud;
● Sealed yeeb nkab threads (R): High precision yog yuav tsum tau, thiab muaj ob txoj kev haum: cylindrical internal threads thiab tapered lwm threads tsim ib "lub tog raj kheej / taper" haum; tapered internal threads thiab tapered external threads tsim "taper/taper" haum.
(1) Qhov loj ntawm cov yeeb nkab xov yog kwv yees tus nqi ntawm cov yeeb nkab sab hauv kab, tsis yog cov yeeb nkab sab nraud. Piv txwv li, 1/2 nti sib haum rau DN15.
(2) Lub thickness ntawm cov yeeb nkab xov daim ntawv yog qhia los ntawm tus xov tooj ntawm threads ib nti, thiab lub converted suab yog ib tug zauv. Piv txwv li, G1 inch yeeb nkab xov muaj 11 threads raws axis, thiab nws lub suab yog 25.4 ÷ 11 ≈ 2.309mm. Cov yeeb nkab xov feem ntau yog siv rau kev sib txuas ntawm cov yeeb nkab fittings thiab nyias- cov phab ntsa, nrog cov suab me me thiab xov daim ntawv loj.
● Metric threads yog qhia los ntawm suab, thaum American thiab British threads qhia los ntawm tus xov tooj ntawm threads ib nti.
● Metric threads muaj 60℃equilateral xov daim ntawv, British threads muaj 55℃isosceles xov daim ntawv, thiab American threads muaj 60℃isosceles xov daim ntawv.
Lus Cim: Cov neeg sab hauv feem ntau siv "fen" los hais txog cov xov loj . 1 nti yog sib npaug rau 8 fen, 1/4 nti yog 2 fen, thiab lwm yam (xws li, 1/2 nti yog 4 fen, 3/4 nti yog 6 fen).
2. Kev xa xov xov
Cov xov xa xov yog siv los xa lub zog lossis kev txav, thiab muaj plaub feem ntau siv cov xov xov:
1) Trapezoidal threads: Daim ntawv xov yog ib qho isosceles trapezoid nrog lub kaum sab xis ntawm 30 degree, uas yog cov xov xov uas siv ntau tshaj plaws. Piv nrog rau cov duab plaub, nws cov kev sib kis tau qis dua me ntsis, tab sis nws muaj cov txheej txheem zoo, lub hauv paus muaj zog thiab kev ua haujlwm zoo. Cov ntsia hlau txhuas ntawm cov cuab yeej siv tshuab siv cov xov trapezoidal los xa lub zog bidirectionally, thiab cov xov code yog Tr.
2) Sawtooth threads: Ib hom kev sib kis xov uas bears unidirectional quab yuam. Daim ntawv xov yog ib qho isosceles trapezoid, ib sab tsim lub kaum sab xis ntawm 30℃nrog txoj kab ntsug, thiab sab nraud ua ib lub kaum sab xis ntawm 3 degree, tsim lub kaum sab xis ntawm 33 degree, nrog cov xov code B. Nws tsuas yog siv los dais lub zog unidirectional. Vim nws txoj kev sib kis tau zoo dua qub thiab lub zog ntau dua li cov xov trapezoidal, nws feem ntau siv rau hauv kev quab yuam unidirectional -cov kabmob xws li cov ntsia hlau nias thiab hydraulic presses.
3) Rectangular threads: Feem ntau yog siv rau kev sib kis quab yuam. Nws cov yam ntxwv yog tias kev sib kis tau zoo dua li lwm cov xov, tab sis kev ua haujlwm nyuaj yog qhov loj thiab lub hauv paus muaj zog tsawg, yog li nws daim ntawv thov raug txwv.
4) Module threads: Kuj tseem hu ua worm iav threads, nrog lub kaum sab xis ntawm 40 degree, uas muaj cov yam ntxwv ntawm kev sib kis loj, cov qauv sib cog lus, kev sib kis tau zoo thiab tus kheej zoo - xauv kev ua tau zoo, feem ntau yog siv los txo cov khoom siv.
II. Mechanical Properties ntawm Bolts
1. Qib: Cov qib zog ntawm cov metric bolts feem ntau suav nrog 10 qib kev ua haujlwm: 3.6, 4.6, 4.8, 5.6, 5.8, 6.8, 8.8, 9.8, 10.9, 12.9.
Distinction thiab lub ntsiab lus ntawm siab - lub zog bolts: Bolts ntawm qib 8.8 thiab siab dua yog sau ua ke hu ua siab - lub zog bolts, thiab cov qib seem yog hu ua dog dig - lub zog bolts.
2. Lub ntsiab lus ntawm bolt kev kawm qib qhab nia: Cov qhab nia qib kev ua tau zoo muaj ob feem ntawm tus lej, sawv cev rau tus nqi nominal tensile lub zog thiab cov txiaj ntsig ntawm tus ntsia liaj qhov rooj. Piv txwv li, lub ntsiab lus ntawm tus ntsia liaj qhov rooj nrog qib 4.8 (Ceeb Toom: Qib 4.8 yog ib qho zoo tib yam - lub zog ntsia liaj qhov rooj, tsis yog siab - lub zog bolt) yog:
(1) Lub zog tensile nominal ntawm cov khoom siv ntsia liaj qhov rooj yog qib 400MPa;
(2) Qhov sib piv ntawm cov khoom siv ntsia liaj qhov rooj yog 0.8;
(3) Nominal yield zog ntawm cov khoom siv ntsia liaj qhov rooj yog 400 × 0.8=320MPa qib.
3. Mechanical kev ua tau zoo qib ntawmboltsFeem ntau muaj plaub qhov ntsuas hauv qab no:
ib. Lub zog ntsuas (lub zog tensile, yield point, yield zog, guaranteed kev nyuaj siab);
b. Hardness indicators (Vickers hardness, Brinell hardness, Rockwell hardness, nto hardness);
c. Plasticity thiab toughness ntsuas (elongation, wedge load zog, cuam tshuam lub zog nqus, lub taub hau firmness);
d. Decarburization txheej ntsuas (qhov siab tsawg kawg ntawm tsis yog -decarburized txheej ntawm xov, qhov siab tshaj plaws ntawm tag nrho decarburized txheej).
4. Lus piav qhia
1) Lub zog tensile (σb) (N / mm²): Lub zog tensile siab tshaj plaws uas cov khoom tuaj yeem dais ib cheeb tsam, hais txog qhov siab tshaj plaws uas cov khoom siv hlau tuaj yeem dais ua ntej tawg.
2) Guaranteed load (SP) (N / mm²): Raws li qib thiab specification ntawm cov khoom, ib tug tej load yog siv rau nws rau ib lub sij hawm ntawm lub sij hawm, thiab cov khoom yuav dais nws yam tsis muaj kev ntsuas mus tas li deformation.
3) Yield point (σs) (N / mm²): Qhov taw qhia qhov kev sib tw nce ntxiv tab sis qhov kev ntxhov siab tsis nce ntxiv thaum cov khoom siv stretched. Nyob rau hauv lub tensile nkhaus ntawm cov khoom uas tsis tshua muaj zog, ib tug pom tseeb yield point yuav tshwm sim, uas yog ciam teb ntawm elastic deformation thiab yas deformation ntawm cov khoom; nyob rau hauv lub tensile nkhaus ntawm high- cov khoom muaj zog, tsis muaj qhov pom tseeb tawm los. Thaum ntsuas qhov taw tes tsis tuaj yeem ntsuas tau, nws raug tso cai siv txoj kev ntsuas qhov muaj zog ntawm qhov tawm los.
4) Lub ntsiab lus ntawm lub zog tawm los: Nws yog qhov txwv tsis pub dhau thaum cov khoom siv hlau tau dhau los ua qhov tshwm sim, uas yog, kev ntxhov siab uas tiv thaiv micro- yas deformation. Rau cov khoom siv hlau uas tsis muaj qhov tshwm sim pom tseeb tshwm sim, nws tau teev tias qhov kev ntxhov siab uas ua rau 0.2% residual deformation yog nws cov txiaj ntsig txwv, uas yog hu ua kev txwv tsis pub dhau los yog lub zog tawm los. Kev quab yuam sab nraud dhau qhov kev txwv no yuav ua rau qhov tsis ua haujlwm tas mus li, uas tsis tuaj yeem rov qab tau. Piv txwv li, qhov kev txwv tsis pub muaj tsawg - carbon steel yog 207MPa. Thaum lub zog sab nraud tshaj qhov kev txwv no, ib feem yuav tsim deformation mus tas li; thaum nws tsawg dua qhov kev txwv no, ib feem tuaj yeem rov qab mus rau nws qhov qub.
Lus ceeb toom:
ib. Cov khoom deformation tau muab faib ua elastic deformation (tuaj yeem rov qab mus rau qhov qub tom qab raug tshem tawm sab nraud) thiab yas deformation (tsis tuaj yeem rov qab mus rau qhov qub tom qab raug tshem tawm, thiab cov duab hloov pauv, xws li elongation lossis luv luv).
b. Thaum qhov kev ntxhov siab tshaj qhov txwv elastic, nws nkag mus rau theem tawm los, thiab deformation nce sai. Lub sijhawm no, ntxiv rau elastic deformation, ib feem ntawm cov yas deformation kuj tshwm sim. Thaum qhov kev ntxhov siab nce mus txog qhov taw tes tawm, cov yas lim tau nce zuj zus, thiab kev hloov pauv me ntsis tshwm sim hauv kev ntxhov siab thiab kev nyuaj siab. Qhov tshwm sim no hu ua yield. Qhov siab tshaj plaws thiab yam tsawg kawg nkaus kev ntxhov siab nyob rau hauv theem no yog hu ua Upper yield point thiab qis yield point feem.
Txij li thaum tus nqi ntawm qhov taw tes qis qis yog qhov ruaj khov, nws yog siv los ua qhov taw qhia ntawm cov khoom siv tiv thaiv, hu ua yield point lossis yield zog (ReL lossis Rp0.2).
5) Hardness: Lub peev xwm ntawm cov khoom siv hlau los tiv thaiv cov khoom siv tawv yog hu ua hardness. Nws yog ib qho kev ua tau zoo ntawm lub cev ntawm cov khoom siv, qhia txog lub peev xwm ntawm cov khoom siv hlau los tiv thaiv elastic deformation, yas deformation los yog tawg nyob rau hauv ib tug me me ntim (cov cim qhia: Vickers hardness HV30, Brinell hardness HB, Rockwell hardness HRB thiab HRC, nto hardness HV0.3).
6) Wedge load zog: Thov ib tug wedge load test rau hexagon taub hau, square taub hau (plaub-kab), hexagon flange lub ntsej muag los yog lub qhov (socket head cap bolts), uas yog, sim lub tensile lub zog ntawm cov khoom tom qab ntxiv ib tug wedge block nyob rau hauv lub taub hau, aiming mus ntes lub tensile zog ntawm cov khoom thiab nws lub taub hau firmness.
7) Elongation (δ): Qhov elongation ntawm cov khoom yog qhov piv ntawm qhov elongation tom qab tawg mus rau qhov qub ntev ua ntej tawg.
① Yield point: Qhov kev ntxhov siab uas tus qauv tuaj yeem txuas ntxiv mus rau elongate (deform) yam tsis muaj zog ntxiv (ua kom tsis tu ncua) thaum lub sijhawm kuaj.
② Upper yield point: Qhov siab tshaj plaws kev ntxhov siab ua ntej lub zog ua ntej txo qis thaum tus qauv yields.
③ Cov ntsiab lus qis dua: Qhov kev ntxhov siab yam tsawg kawg nkaus hauv theem tawm los thaum tsis pom qhov cuam tshuam thawj zaug.
Qee cov hlau (xws li siab - carbon steel) tsis muaj qhov tshwm sim pom tseeb. Feem ntau, qhov kev ntxhov siab uas micro- yas deformation (0.2%) tshwm sim yog coj los ua lub zog ntawm cov hlau, uas yog hu ua lub zog yield zog.
8) Lub taub hau ruaj khov: Txhim kho cov khoom rau hauv kev txhawb nqa nrog lub qhov inclined, thiab ntaus lub taub hau khoom. Raupuv - xov boltslos yog screws, tsuav yog tsis muaj lub taub hau -tawm tshwm sim, txawm yog cov kab nrib pleb tshwm nyob rau hauv thawj xov, nws yuav tsum tau suav hais tias raws li qhov yuav tsum tau ntawm qhov kev xeem no; rau ib nrab- xov cov khoom, tsis muaj cov kab nrib pleb yuav tsum raug tsim ntawm lub taub hau, qhov chaw txhawb nqa thiab kev hloov pauv ntawm qhov chaw txhawb nqa thiab cov ntsia hlau pas nrig. Raws li GB / T 3098.1, qhov kev sim no yuav tsum tau ua rau bolts thiab screws nrog specification Tsawg dua los yog sib npaug rau M16 thiab ntev ntev dhau los ua qhov ntsuas qhov ntsuas.
