Ph mg phdp đng dang (t mg tg hinh hoc)

P h m g phip đng dang 1 i p h m g phhp dun giin nhilt, dqa vio cic bum

m5u

c6 san hogc chc bum md hinh c6n, Mcmg

tq.

viec nhan cdc'kich thudc cda bum thuc vh bum miụ D& tinh to6n the0 phrrmg phip

dH ntu ngulti ta phHi c6 bin thibt kb chudn cha born m b hoQc bum rn6 hinh, dgc

tinh nang lumg cfia bum d& dua vio d 6 x5c djnh he s6 chuygn đị Trong t n h g h* kh0ng c6 b i n thiQ

k&

c h v& th6ng si5 nang luqng ciing nhu hi@ sugt clia bum.

CAc kich thubc ca bin c8a binh c0ng tic xac djnh theo phucmg tr'hh d6ng dang :

f i

C = K , X--

n (3.26)

He st5 tf 1e 88ng dang the0 bum m6 hinh:

6) P h m g phiip mot @ad@

Phucmg phap mot toa do lh phuung phip thi& kk d m gi%n h u n g c6 hi@ qui, pr6fin cinh thi&'t

k$'

hbi ngu& thikt

kk

Phumg phhp Iuc nang lj. phumg phPp d q c sir dung r6ng riii b c6c nudc TAy

Au,

tigt

m6i ti& dien lh mgt prdfin, chc prbfin tumg h g vdi m6i tiEt dien khac nhau sE c6

cAc he so" luc nang khdc nhau, n6u chon prbfin khi dbng thoi miin chc he s6 luc nang vA luc chn tbi

uu

khi xAu c6nh sE kh6 d%m bAo su subn deu cha 16 chnh. Chinh vi vgy, trong qu6 tr'hh thigt kk phAi vE vB di$u chinh cAc thdng s6 n h i h Ian tao ra kh6 khan cho vi&c lap trinh v i tlnh tohn trkn may vi tinh. Phumg ph5p nay c6 uu diem lh khdi Iuqng tinh to6n d m giIn vh sir dung cLc prdfin

khi

dude

kk

Phumg phdp X m Z dua trkn giA thuygt 118 do cong c6a d u h g nhan prdfin c6 anh hdmg quygt d m tdi luu s6 v+n t6c hay do cinh tao nen, vi v+y, ciing Anh h ~ h g quye"t djnh tdi lgc nang tic dung 1Cn prdfin cinh. Dqa theo quan h& cha lgc nangC,, vdi l m s 6 v+n t6c bao quanh prdfin vP quan he c6a lqc nAngC, vdi g6c dac tnmg cho 66 cong c i a prdfinp, ta xLc d~ dudc ggcp, theo c i c th&ng sB hinh hoc v i dong hoc cha ciinh. Trong tntirng h* nhy d ~ h g nhhn cha prbfin 1P mot cung trbn.

e ) Phu;mg phhp Bauerospheldo

Gia thi&'t t h h h phAn quay cua vgn t6c vbng cfia xoiiy Litn h* bi triet tiCu

w , = 0 . Phuang phiip nPy d ~ g c sir dung rong r l i dB tinh toin thi&

kC

Dqng d u h g dong thg trong ti& dien kinh tuygn cfia bAnh c6ng tic SE d ~ g c

d u h g dong S, c i c d ~ b n g deng thbo vh tntbng v+n tbc

V , .

Theo diZu ki&n song song c6a vkc-ta xoLy be mat l i c5nh F ta c6:

Ti& dien kinh tuyen be mgt l i c h h F m t r h g v6i cic d u h g xoiy thinh phinọ. Nghia lA, vdi c l c d ~ h g e ~ .r = consr n h tr&n mgt phi!ing kinh tuygn, & mat bang sE la cac d u h g thang.

Cho quy luat thay đi V, .R = f (6)d6i vdi mot trong chc d u h g dbng vdi gi9 trl

V m , ta c6 th& xay d q g

dude

li

lii c h h vdi b& mat d u h g dbng:

GiH si3 qui

lust

Trong thqc te, ttich phan nBy thubng d ~ g c cho d ~ d i dang bing.

fl

CBc phumg ph6p tinh to6n cha Vbzonhexenski-P&kin v i Uxdkhin-SimBnBv c6 noi dung co bAn gi6ng nhau, the0 c6c ph~cmg ph5p nay t5c dong c6a cdc profin l&.n dbng chgt llbng d ~ u c thay thg bbi c5c xo5y phan b6 doc d u h g nhan theo mgt quy

lust

DQ

lust

Di&u kh5c nhau chinh giila hai phumg phAp Ih: theo phumg phap Vbzunhexenski - P&kin coi dubng nhdn la mot cung trbn khi 66 c6 th6 giii dudc phuang trlnh tich phan h i m dhng cha d u h g dbng tao b&i dbng song p h h g khbng n h i h vA dbng xoiy tao bbi cAc xoiy lien hap phdn bd tren dubng nhdn cha t$t cci cac prbfin trong ludị Cbn theo phumg phhp LBxBkhin - SimBnBv d u h g nhdn cha prbfin la mot cung cong bai

kp

thd

gdn dling lien ti&p. W v+y, vi&c giAi phucmg tr'inh tich phan sE rgt ph3c tap, nhung

dip lai, ph-g ph8p nhy cho c i c k&t q u i phG hop hun vdi bin chgt dbng chiỵ 3.2. Tinh toan thiét ke"

may

3.2.1. Cuc yku cdu

ky thuut tir thqc

Thqc t6 sin xu&

ir

m9y b m , c6 th6 d8u ttu nghien c h , thigt kg, chg tao c9c m9y b m dbng ch6o v& he s6 tf t6c cnS = 469v / ph

,

Q = 900 m 3 / h .

3.2.2. Tin

h

thuat ctr

h

fric

chko

Sq phAt tridn c6a khoa ha, cdng nghe ciing

nhu