Compression springs khaws txhua lub zog thaum compressed thiab tso tawm txhua lub zog thaum lub load raug tshem tawm. Txawm hais tias compression springs feem ntau yog ua los ntawm lub caij nplooj ntoos hlav steel, lawv kuj tseem muaj cov pa roj carbon, magnesium, npib tsib xee, chromium, tin, tooj liab, tungsten, thiab txhuas.
Cov ntaub ntawv sib txawv tsim cov qib sib txawv ntawm elasticity thiab lub zog cia muaj peev xwm rau compression springs.
Robert Hooke tau npaj ib qho qauv thaum ntxov li 1676 los xam cov quab yuam los ntawm lub caij nplooj ntoos hlav, uas yog proportional rau nws elongation.
Compression springs yog cov cuab yeej siv tshuab tshwj xeeb tsim los rau kev nkag siab axial compressive loads. Feem ntau lawv tuaj yeem ncab thiab tig mus rau ib qho taw tes. Feem ntau hais lus, compression springs tuaj yeem khaws txhua lub zog thaum raug compressive loads. Thaum lub load raug tshem tawm, lawv yuav rov qab mus rau lawv qhov qub zoo thiab qhov loj me - tab tom ua elastic deformation.
Qhov tshwj xeeb muaj peev xwm khaws cia lub zog muaj peev xwm, ua ke nrog nws cov txheeb ze simplicity thiab pheej yig, ua rau compression springs muaj txiaj ntsig hauv ntau yam kev siv. Los ntawm cov tshuab keyboards, lub txaj thiab cov cwj mem ballpoint, mus rau phom thiab lub tsheb ncua kev poob siab absorbers. Txij li thaum xyoo pua 15th, peb tau siv compression springs, thiab thawj lub caij nplooj ntoos hlav compression tau siv rau hauv cov khoom siv moos.
Hom compression springs
Compression springs tuaj yeem muaj ntau yam duab geometric sib txawv. Cov feem ntau yog cov coils los yog kauv springs. Cov duab no nrov dua li lwm cov duab vim nws tso cai rau seamless siab compression thiab nthuav mus rau qhov taw tes. Nws kuj yog sib dua vim nws siv cov ntaub ntawv tsawg dua kom tau raws li qhov xav tau ntawm absorbing compressive loads. Thaum kawg, cov duab ntawm lub caij nplooj ntoos hlav coil muab hom no rau lub caij nplooj ntoos hlav loj tas li (uas yuav piav qhia meej tom qab).
Pawg no tau muab faib ua subcategories, suav nrog:
Cov khoom ntawm compression caij nplooj ntoos hlav
Compression springs feem ntau yog ua los ntawm lub caij nplooj ntoos hlav steel, uas yog ib hom hlau uas muaj zog yield zog. Qhov no tso cai rau lawv khaws lawv cov duab qub, qhov loj me, thiab cov duab txawm tias deformed mus rau qhov kawg. Yog li ntawd, cov hlau no muaj qhov loj elastic deformation qhov chaw nyob rau hauv kev ntxhov siab. Qhov no tshwm sim ntawm qib molecular, yog li qhov muaj pes tsawg leeg ntawm cov hlau no muaj feem cuam tshuam rau lawv elasticity.
Feem ntau hais lus, lub caij nplooj ntoos hlav hlau muaj carbon thiab manganese, nrog rau npib tsib xee, chromium, molybdenum, tin, vanadium, tooj liab, hlau, tungsten, thiab txhuas. Lub caij nplooj ntoos hlav steel yog cais los ntawm cov nom ASTM raws li nws cov khoom muaj zog thiab hardness, yog li cov khoom sib txawv tuaj yeem tsim nyog rau kev siv sib txawv. Piv txwv li, ASTM A228 yog siv rau cov hlua piano, muaj 0.7% -1% carbon thiab 0.2% -0.6% manganese, nrog rau qhov siab tshaj plaws Lub zog ntawm 530 megapascals thiab lub zog tensile ntawm 400 megapascals.
Cov yam ntxwv ntawm compression springs
Hauv seem no, kuv yuav tsom mus rau kev qhia txog cov khoom siv hluav taws xob uas tsis muaj coiled, vim tias cov springs no feem ntau siv compression springs. Cov springs no muaj qee yam yam ntxwv uas muaj qhov tseem ceeb rau lawv qhov kev ua tau zoo. Sab nraud txoj kab uas hla (D) yog hais txog txoj kab uas hla ntawm lub tog raj kheej tsim los ntawm lub caij nplooj ntoos hlav thaum saib los ntawm sab saum toj. Lub coil txoj kab uas hla yog hais txog lub thickness (d) ntawm lub caij nplooj ntoos hlav hlau, uas kuj yog cylindrical. Qhov ntev pub dawb (L) yog hais txog tag nrho qhov ntev ntawm lub caij nplooj ntoos hlav yam tsis muaj compression, thaum lub helix (na) thiab tag nrho helix (n) yog tus naj npawb ntawm cov coils uas khaws thiab tso tawm lub zog siv tshuab, thiab tus naj npawb ntawm cov kauj tsheb npav ( tsawg kawg yog ob lub siab rau qhov kawg / puag ntawm lub caij nplooj ntoos hlav). Lwm qhov tseem ceeb morphological cwj pwm yog cov kev taw qhia ntawm kev sib hloov, uas tuaj yeem sab laug lossis sab xis.
Lub zog quab yuam los ntawm lub caij nplooj ntoos hlav yog proportional rau nws elongation, ib txoj cai los ntawm Robert Hooke nyob rau hauv 1676, nyob rau hauv ob peb xyoos luv luv ntawm thawj lub caij nplooj ntoos hlav daim ntawv thov. Hooke tau qhia cov qauv no rau lub ntiaj teb. "F=- kx", qhov twg F yog lub caij nplooj ntoos hlav quab yuam, x yog qhov kev ncua deb, thiab k yog lub caij nplooj ntoos hlav tas li. Txhua lub caij nplooj ntoos hlav sib txawv thiab txiav txim siab los ntawm cov chaw tsim khoom los ntawm kev sim lossis los ntawm cov neeg siv los ntawm cov qauv. K=Gd4/[83dna]. Raws li tau hais ua ntej, chim thiab conical coils yog nonlinear springs, yog li Hooke txoj cai tsis siv rau lawv. Hooke txoj cai tsis siv rau cov springs uas twb deformed los yog tshaj qhov kev txwv dav dav.
Lub zog ntawm lub siab compressed caij nplooj ntoos hlav
Txhawm rau xam qhov quab yuam ntawm lub caij nplooj ntoos hlav compressed, peb tuaj yeem siv cov qauv no. Fmax=Ed4 (L-nd)/[16 (1)+ ν) (Dd) 3n]. E yog tus Young's modulus, d yog txoj kab uas hla ntawm cov hlau xaim, L yog qhov ntev dawb, thiab n yog tus naj npawb ntawm cov helices / coils, ν Nws yog Poisson tus piv, thiab D yog lub taub sab nraud. Nws yog qhov pom tseeb tias qee qhov ntawm lawv tau txiav txim siab los ntawm cov hlau xaiv los ntawm tus tsim qauv, thaum lwm tus txiav txim siab los ntawm daim ntawv, cov duab, thiab qhov loj ntawm lub caij nplooj ntoos hlav.
Kev xav txog kev tsim qauv
Thaum tsim lub caij nplooj ntoos hlav compression, thawj qhov kev txiav txim siab yog yam khoom koj xav siv. Tom qab ntawd nrhiav cov shear modulus (G) thiab tensile zog (TS) los ntawm cov ntaub ntawv rooj. Ob yam no yog qhov tseem ceeb rau kev txiav txim siab qhov feem pua ntawm kev ntxhov siab, piv txwv li, thaum xam cov kev xav tau ntawm cov load (100 * σ/ Xam cov degree uas lub caij nplooj ntoos hlav compressed thaum muaj qee yam load yog induced, raws li lub zog tensile.
Lwm qhov kev xav tseem ceeb yog txoj kab uas hla ntawm lub caij nplooj ntoos hlav thaum compressed rau nws qhov siab tshaj plaws. Kauv compression springs yuav nce nyob rau hauv txoj kab uas hla thaum compression. Yog li nws yog ib qho tseem ceeb los xam qhov kev nthuav dav no siv cov qauv "expansion={sz [(Dd) 2+(p2-d2/π 2)+d] - D}".
Qhov ntsuas ntawm lub caij nplooj ntoos hlav yog ib qho tseem ceeb, thiab cov neeg tsim qauv sim ua kom nws nyob hauv thaj tsam ntawm 4 txog 10. Nws txoj kev suav yog "C=(Dd/d)", uas muab lub tswv yim zoo ntawm qhov piv ntawm cov hlau. thickness mus rau lub caij nplooj ntoos hlav diam. Qhov no yuav txiav txim siab tag nrho lub zog ntawm lub caij nplooj ntoos hlav (me me yog muaj zog dua, tab sis loj dua yog yooj yim rau compress).
