Cov ncauj lus ntxaws ntxaws kom txiav txim siab qhov yooj yim ntawm cov hinged plaub-bar mechanism los ntawm kev siv hinged f

Nthuav ntawm kev tsom xam ntawm kev sib txheeb ntawm kev sib txheeb ntawm cov neeg txheeb ze thiab txoj cai ntawm cov kab sib txuas, peb tuaj yeem tshuaj xyuas cov xwm txheej sib txawv los kos cov kev ntsuas pom. Los ntawm kev txiav txim siab qhov loj me thiab txoj haujlwm ntawm txhua tus pas nrig, peb tuaj yeem txiav txim siab daws teeb meem rau ntau hom kev xav tsis thoob hauv lub xeev.

Kev txheeb ze loj tuaj yeem faib ua peb kis. Hauv thawj kis, thaum "ad < bc" and a and b are adjacent bars, we can take the shortest bar (a) as the reference member and analyze its relative motion with the two adjacent bars. Since "a < b" and "c < d", we can conclude that rod a can be straightened and collinear with the two adjacent rods. In other words, a can overlap and be aligned with the neighboring rods.

Txhawm rau tsim qhov kev cuam tshuam no ntau, cov kev tsis sib xws tom qab yuav tsum tuav: "D + C> B + A". Qhov no qhia tau tias "C + A", uas yog sib xws nrog cov kev mob muab. Ib qho ntxiv, nws tuaj yeem ua pov thawj tias ib qho tseem tuaj yeem ua kom dhau thiab collinear nrog tus pas nrig sib luag (c), siv ib qho kev xav zoo sib xws. Li no, tus ncej rov qab (b lossis c) ntawm luv tshaj bar (a) tsuas yog muab rov qab rau ob sab uas nyob ntawm lub kaum sab xis tsawg dua 180 °. Qhov no txhais tau tias lub kaum sab xis ntawm viav vias raug txwv tsawg dua 180 °, tab sis ntau dua 50 ° (as per mob).

Hauv qhov xwm txheej thib ob, thaum A thiab B yog ib yam li qub, tib txoj kev tuaj yeem siv rau ua qhia tau tias qhov luv tshaj plaws bar (a) tseem tuaj yeem tig rov qab rau ob kab uas nyob ib sab. Yog li ntawd, peb tuaj yeem txiav tawm txoj kev sib tham ntawm cov xwm txheej no.

Hauv qhov xwm txheej thib peb, peb xav txog cov txheeb ze cov lus tsa suab ntawm qhov ntev tshaj plaws bar (d) thiab ob kab txuas nyob ib sab. Los ntawm cov neeg paub tseeb, peb tuaj yeem txiav tawm cov lus uas "D> B + AC" thiab "D> E + AB". Qhov no txhais tau tias ROD d tsis tuaj yeem ncaj thiab collinear nrog ob lub pas nrig nyob ze. Tsis tas li ntawd, yog tias D yuav tau overlapped thiab collinear nrog cov pas nrig sib ze, peb yuav muaj "d + a" b + c "(cuam tshuam rau cov kev pab cuam). Yog li ntawd, peb xaus tias tus pas nrig d tsis tuaj yeem sib tshooj thiab muab colinear nrog cov pas sib ze sib ze. Hauv cov xwm txheej no, ob lub kaum ob ntawm viav vias raug txwv tsawg dua 180 °.

Sib txuas ua ke cov lus xaus ntawm thawj, thib ob, thiab peb tus neeg thib peb, peb tuaj yeem piav qhia qhov ntawd, raws li qhov xwm txheej ntawm "ad < bc", regardless of the various positions, the shortest bar (a) and the second adjacent bar (b) can rotate relative to each other for a whole circle. However, the opposite pole (b or c) and the two adjacent poles of the shortest bar can only swing relative to each other, with the relative swing angle being less than 180°.

Los ntawm cov ntsiab lus ntawm ob qho kev sib txheeb ntawm ob lub pob zeb hinged nyob rau hauv hom plaub-bar Kinematic saw, peb tuaj yeem yooj yim txiav txim siab hom kev siv tshuab los ntawm kev xaiv ib tus pas nrig ntawm kev siv. Piv txwv li, yog hais tias tus pas nrig luv tshaj plaws (a) nrog sab nyob ib sab yog siv los ua cov ncej, ib qho crank-rocker tshuab yog tau. Ntawm qhov tod tes, yog tias qhov rov qab ntawm tus pas nrig luv tshaj plaws yog siv los ua cov ncej, ib lub tshuab pa sib xws li muaj. Nws yog ib qho tseem ceeb kom nco ntsoov tias cov foob pob zeb, hauv cov ntaub ntawv tom kawg, tsis tuaj yeem viav vias mus rau txoj kab sib tsoo, thiab lub viav vias txuas ntxiv rau qhov tsawg tshaj 180 °.

Hauv kev xaus, dhau ntawm kev tsom xam ntawm kev sib raug zoo ntawm cov lus tsa suab, ib qho kev txheeb ze loj, peb tuaj yeem txiav txim siab hom kev ua haujlwm thiab nws cov kev txwv. Los ntawm kev nkag siab cov ntsiab cai no, kws tsim txuj ci thiab cov tsim qauv tuaj yeem tsim kho thiab ua kom zoo dua ntau yam kev siv rau cov ntawv thov tshwj xeeb.