NGHIEN CUfU TRAO DOI
y NGHIEN CU'U ANH HU-^WG KHE H& GlQ-ACa CAU KEO BANG VA KHAU CO S& D i N SUNG DAI LIEN PKMS KHI B A N
RESEARCH EFFECTS OF GAP MAGAZE^TE OPACITY AND BASIC LINK TO MACHEME GUN PKMS
NCS. Vu Xuan Long Hpc vien Ky thuat Quan Su
TOM TAT
Bdi bdo trinh bay mo hinh tinh todn, xay dimg he phucmg trinh viphdn chuyin dong khi ki din khe hff khop dong vd khau ca so siing dai lien PKMS. Khdo sat, phan tich, ddnh gid dnh hu&ng cita khe ha khop dong den qud trinh Idm viec cua mdy tu dong.
Tir khoa: Dong luc hoc, khdo sat, phan tich, ddnh gid, khe ha khop dong, dai lien, mdy tu
ABSTRACT
This article presents a computational model, construction ofdiffirential equations when moving joints mention the gap and stitched machine guns basics PKMS. Study, analysis, estimate effect of the joint gap to working process of automatic machine.
Keywords: Dynamics, study, analysis, estimate, the joint gap, machine guns, automatic machine.
1. DAT VAN DE td khe ha luon t6n tai, vi vay, co thJ xuit hien chuyen dpng tu do ciia can keo bang trong pham Khi tinli toan thiet ke ca cau tiSp dan bing vi khe ho lien kSt. ChuySn dpng cua cin keo bang day bang yeu cau dat ra la: Nang luong tieu hao it; dan xen giiia chuy6n dong cuSng biic va quan Luc quan tinh nho; Khong xay ra va cham trong tinh vi vay xay ra va cham, bi6n dang lam anh qua trinh lam viec. Vai gia thiit hen kSt giOa cin huong din qua trinh tiSp dan ciia siing trong qua keo bang va be khoa khong c6 khe ha. Trong thuc trinh b jn.
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NGHIEN CUfU - TRAO D O I
2. MO HilVH TINH TOAN VA HE PHlTONG TRINH VI PHAN CHUYEN DONG
ho, ta CO he phuang trinh vi phan chuyen dong ciia khau co sa va ca keo biing dan.
-^ =4==
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Hinh 1: So do lien ket giiia khau co sd vd khdu lam viec Phuong trinh dao dpng cua khau lam viec
-fe-'^:
i6}-m^^v^ ~'"i4 ^'"is*^)x = v^;f = Q)\z= i x ; z. =k.,z^= k,J; i,. = k,.
UE-lPiL -kJ. \:k.
ifVL^.
thiii: N+P
(1)
(4)
Trong dd, khdi lugng thu gpn va lye thu gpn dupe tmh theo bi6u thuc:
Trong do: N-= c(x-- x,j): Luc dan hdi tac dung len khau thii i; x^^: vi tri thue eua khau thur i khi tinh tdi bien dang; x^: vi tri can bang, tuong ling vdi vi tri khi coi khau thii i la cung tuyet ddi; P^: ngoai lye tac dung len khau thu i; c:
Dg Cling thay the ciia khau thu: i.
Trong truong hgp chuyen ddng eiia khau CO sd bao gdm chuyen dpng tinh tien va chuyen ddng quay thi van tdc khau lam viec thii i la tdng hai thanh phan vee to van tdc:i:, —k^^x + k^^q?.
Ty sd truydn thuc bao gdm hai dai lugng:
-.-t4--i]^l<. 'nn-J.^t'^'n (5)
= > m, '" "^t m., = > m it 1, Sf ' i! • lay -
llN^rtP^
l(K+P^i
to[ m,•k.,.i.
- k,^,d}
(2)
Va cham chi xay ra mot phia vdi lien ket khdng giu, ddi vdi lien ket giii se xay ra d ca hai phia. Vi vay, cd the bieu dien ham N(e) mot each tdng quat nhu sau:
Khi tdn tai khe hd trong cac khdp ddng, phuong trinh lien ket duge thay bang hai bat dang thiic cua lien ket khdng giu viet ve hai phia. Bien dang khau thii i liic nay se la:
= (jc, - A £ - , - - J : „ )
\ + sign{x^-/S.s,-x,,)
Trong do lye can day bang duge tinh theo cdng thiic:
\P^,=\.\x^hn
(3)
Kdt hgp he (2) vdi he phuong trmh vi phan may ty ddng khi kh tdi anh hudng cua khe
, , l-s/ew(x+Af -x,\
+ (x,+As,-x„) i ^ ^ '-^^ (7) Nhd ham lay dau sign nen e^O khi x- As<Xj^<x+A8. Vung nay gpi la viing khdng ti8p xiic. Trong vimg nay N =0.
Ket hgp vdi he phuang trinh ca ban bai toan thuat phdng trong, he phuong trinh vi phan buong khi, he phuang trinh vi phan may ty ddng.
Giai bang phan mem Matlab. Ta cd cac ket qua'^
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NGHIEN CUfU-TRAO D C I
nhan xet anh hudng cua khe hd khdp ddng giiia CO eau keo bang va khau co sd nhu sau.
3. ANH HirOfNG CUA K H E H d CAN K E O BANG VA KHAU C O S d DEN SUNG DAI LIEN K H I BAN
Khao sat anh hudng tdi sy lam viec ciia may tu ddng khi khe hd tiep dan thay ddi. Ta se nghien ciiu anh hudng den cac tham sd dpng hpc ciia khau co sd nhu van tdc, quang dudng chuyen ddng.
Miic dp anh hudng ciia khe hd tiep dan tdi lye keo bang dupe minh hoa tren hinh 2. Dd thi la ket qua tinh toan lye keo bang tuong ling vdi sau truong hgp khe hd tidp dan: A,j-[0.25; 0.5; 0.75;
1.0; 1.25; 1.5]mm.
Hinh 3: Hinh ddng quy dgo luc keo bdng tren doan keo bdng
Khi khe hd tiep dan tang, thdi digm va cham khi bat dau hanh trinh tilp dan xay ra trong
doan tang tde cua be khoa. Hien tugng tri lam cho van tde cua be khoa tai thdi diem va cham tang. Lye keo bang tang dot bidn tuotig ling vdi budc nhay tai A tren dd thi hmh 2. Dudng ngoai Cling ve ben trai va dudng tiep theo tuang ling vdi cac gia tri tang dan ciia khe hd da neu d tren. K^t thiic hanh trinh keo bang (diem B) can keo bang rdi khdi doan ranh nghieng eua cam tiep dan.
Tren dd thi hinh 3 eiing cho thay hinh dang do thi lire keo bang cd hinh rang eua. Di8u nay minh hpa cho gia thiet va cham lien tuc tat dan giiia can keo bang va mat cam tiep dan.
Hinh 4 la ket qua nghien eiiu anh hudng cua khe hd tiep dan tdi qua trinh lam viec ciia may tu dpng vdi gia thiet khe hd la khdng ddi dpc theo mat cam tidp dan.
1 '
r^^^h
,».".s„
..^T:™™ ..
1 "
w „
•^-••••"•••.,
™,°i".,.,
f-^n^-;:]- ,:
*—!—.JHinh 4: Bo thi van tdc vd quang dudng chuyin dong ciia be khod khi khe hd tiep dgn thay doi
Trong da sd cae trudng hgp, khe hd co gia tri thay ddi do mon khdng deu trong qua trinh khai thae. Trong thuc te, viec xac dinh chinh xac khe hd tigp dan dpc theo dudng tidp xue giiia be khoa va ckn keo bang la rit kho khan. Mot phuang phap kha thi la xac djnh dp do eiia eSn keo bang khi cho be khoa liii, rdi suy ngupc ra gia tri khe hd tai cac vi tri tuong ling.
Hinh 5: Bien dgng cua can keo bang &(X)
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NGHIEN CLUU - TRAO D 6 I
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Hinh 6: Luc keo bdng PJX) 1) Khe hd khdng ddi; 2) Khe hd thay ddi
Kdt qua tinh toan tren hinh 5, cho thSy tren hanh trinh keo bang, khi khe hd khdng ddi (Aj^=0.2mm), bien dang la don dieu giam trong khi trudng hpp khe hd thay ddi (hinh sin va ed gia tri Idn nhat b5ng 0.2mm), bien dang cd dang dao ddng tuan hoan. Bi6n dang thay ddi tuin hoan lam cho chi tiet nhanh bi pha huy do mdi. Tuong ty nhu bien dang, bien do dao dgng eua luc keo bang khi khe hd thay ddi la Idn hon so vdi trudng hgp khe hd khdng ddi (hinh 6). Su thay ddi nay lam cho day bang trong qua trinh lam viec bi rung ddng manh, lam anh hudng tdi dp hhu ciia day bang, anh hudng tdi su dn dinh cua siing khi ban.
4. KET LU4.N
Sy thay ddi hinh dang khe hd anh hudng chii yeu tdi do ben cua cSn keo bang va day bang. Cac ket qua tinh toan toan khae eho thay chuyen ddng eiia khau co sd va ciia may tu ddng hi anh hudng khdng dang ke khi hinh dang khe hd la mpt ham tron, hen tuc.
Tinh toan ddng lue hgc may ty ddng khi ke tdi khe hd tiep dan nham han che eac sai sd ddng hgc ciia bd phan tiep dan, xae dinh chinh xac ling luc tae dung len ea cau. Khao sat anh hudng ciia khe hd CO eau tidp dan va khau co sd phuc vu cho tinh toan thiet ke khi lya chpn vat lieu, xae dinh hinh dang, kich thudc eua chi tilt. Kdt qua tinh toan can thiet khi tmh toan kiem ben cho chi tiet.<*
Ngay nhan bai; 21/4/2014 Ngay phan bien: 20/5/2014 Tai li^u tham khao:
[1]. Pham Huy Chuong (1998), Oerlikon sach tra cuu vu khi, (sach dich). Hoc vien Ky thuat Quan su, Ha Noi.
[2]. Pham Huy Chuong (2002), Dong luc hoc vii khi tu ddng. Hoc vien Ky thuat Quan sy, Ha Noi.
[3]. TrSn Hdng Thanh (2006), Nghien cim dnh hudng cita khe hd khdp dong tdi qud trinh Idm viec ciia mdy tu dong, Luan an TiSn si. Hoc vien Ky thuat Quan sy.
[4]. B.B. AJi4)epoB (1977), KoHCxpyKUHa H pacner aBTOMaTHHecKoro opyacna. MarnHHOcxpoeHHe, MocKsa.
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