I. Loi s~tcua nam chiimdi~n; 2 LO xo; 3.Thanh SQC;
R-Ban kinh tae d\lllg eua qua dfun, (m) h Chi€u sau tae d\lng eua qua dfun, (m).
h - Chi€u sau tae d\lng eua qua dfun, (m). tl - Thai gian dfun t(li mQt ehe;, (s). t2 - Thai gian di dQng dfun, (s). ktg - H~ s6 thai gian su d\lng may.
(6-3)
6.4. MAvV ~N CHUVEN BE TONG 6.4.1. May bam betong
1KMi ni~m: May bam be tong dUng d~ v~ chuy~n va db be tong t~i ch6 theo m(\t duang bng dful bfutg thep. Sir d\ll1g may bam be tong r~t phil hQ'P v6ivi~c thi cong tbng hQ'Pva-l\l d(\ng hoa, dbng thOi dam bao duQ'c phk ch~t be tong trong khi v~ chuy~n, nhu tranh duQ'c hi~ntugng phan tAng va chay nuac xi mango
NhuQ'c di~m la kho kh6ng ch~ duQ'c s6 lugng be tong trong hic v~ chuy~n, thanh phfut be tong bi h~ ch~ trong trong ph~ vi nh~t dinh (c6t li~ukhong duQ'c to qua, kh6i lugng be tong khong nho qua) pMi t6n cong rfra s~h may va duang 6ng sau khi dUng, C\I Iy v~ chuy~n ngiin va yeu du trinh d(\ cong nhan quan Iy va sir d\lllg cao ...
a. cAu ttiO va nguyen If lam vi~e:
* May bO'lD kiSu piston:
SO"dA nguyen If eua IOtlimay bO'lD 1piston (lo~i van xoay)
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b)
Hinh 6.15: Bam betong rnQt piston a. Hanh trinb hUt; b- Hanh trinb ddy
1- Van hut; 2- Van ddy; 3- Thi8t bid~ v~t li~u; 4- Thi8t bitrQnbe tong; 5- Xilanh; 6- Pitong; 7- Ph8u ti8p li~u.
8- Dng dan
Than bam g6m co xilanh va h(\p van, trong hQp van d~t van hUt va van dAy. Ben trong xilanh la ao xilanh. D~ ch6ng mili mon, ao xilanh duQ'c lam bfulg m(\t hQ'Pkim rAt
tbt vii duQ'c toi luy~n kyo Ben trong ao xilanh ~t piston co dAu bfutg cao suoNhu v~ykhi lam vi~c chi co ao xilanh Iii ti~p xuc trgc ti~p vm be tong nen xilanh duQ'c bilo v~. Khi hu hOng chi cfut thay ao xilanh chu khong cfut phai thay xilanh. D~ giam bat rna sat va tranh vfra an mon ao xilanh, trong khi piston lam vi~c, luon luon co nuac tum ra rna s~h phfut ao xilanh adfulg sau piston.
Van hUt va van dAy be tong thuQc 10(livan xoay dung d~ dong rna duang dful be tong vao xilanh vii dAy be tong vao 6ng dful. No lam vi~c duQ'c la nhiYS\I truyen l\Ic cua ca cAu lien d(\ng vii thanh keo.
Khi piston keo ra thi van hUtrna, van dAy dong 1(Ii, be tong duQ'c dAy vilo thi nguQ'c 1(Iivan hUt dong, van dAyrnado do be tong duQ'c dAy vilo 6ng dful. D~ tranh hi~n
tugng k~t da lam hu hong van vii d~ be tong luonatJ1mgthai luu dQng,khong bi phan tAngngum ta lam cac van d6 khong bao gia d6ng kin hoan toan milluon co mQtkhe h&000..