NGHIEN cuiu KHOA HOG
V'
DONG Ll/C HOC THIET Bj CONG TAC MAY XUC THUY Ll/C TICH n a p OTA CAT BE T O N G COT THEPDYNAMICS OF CUTTING PROCESS REINFORCED CONCRETE OF THE EQUIPMENT INTEGRATED WITH A HYDRAULIC EXCAVATOR
PGS,TS. L l Hdng Phfldng', NCS,ThS. Le Anh Stfn^
'Vien Ky thuat Cd gidi Quan sfl, Tdng cue Ky thuat
^Khoa Ddng lflc, Hpc viln Ky thuat Quan sfl
T6M TAT
May xue thuy lUc Id logi mdy chu dao trong cong tdc cd gidi hda. no dUdc sd dung rgng rdi trong edc linh vUc khai thde mo, nong nghiip. cong nghiep vdi cdc chdc ndng chinh nhU ddo dap, san ldp vd van chuyen vdt lieu. Hien nay, viic sd dung cdc bg cong tdc di kem vdi mdy xue cho thdy tinh kinh ti vd hieu qud cao. Bdi bdo dd thiet lap md hinh ddng lUc hgc to hdp mdy xdc - thiet bi cat be tdng cdt thep vd kit qud tinh todn cdc ddc trUng dgng lUc hgc. Kit qud nhdn dUdc Id cd sd de hodn thien thiit bi cd ve kit cdu vd khia canh dieu khien.
Td khda: Dgng lUc hgc.
ABSTRACT
Hydraulic excavators are high power machines used in the mining agricultural and construction industry whose principal functions are digging (material removing), ground leveling and material transport operations. Currently, the use of the excavator attachments showed the economy and efficiency. This paper presents a dynamic model and results of the characteristic during cutting process of a hydraulic excavator integrated cutting disc reinforced concrete on based the mechanical theory of multi-body systems. The results of work are scientific basis for improving structure anf control of equipment.
Keywords: Dynamics.
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I.DATVANDE
Da nang hda cae dang thiet bi edng tae cua may xdc thuy lflc la mot xu hfldng rat pho biln hiln nay. To hpp thiet bi nay cho phep sd dung dflpc kha nang thdng qua tdt eda phan di chuyin va pham vi vdi tdi rdng eua thilt hi edng tac cda may xdc cho viee thfle hiln cac ehdc nang md rdng nhfl: Dam len, ddng cpc, due pha, khoan cat,...
Ddng lflc hpc cac dang thiet bi cdng tae da nang la mot v&i de cdn it dflpc quan tam.
Khi tieh hpp cac thilt bi da nang len may xue, eac cdng trinh mdi ehi quan tam den eac yeu td edng su£t va nang suat cua thiet bi.
Tinh toan khao sat ddng lflc hpe thiet bi eat se gdp phan tao tiln d l cho eae bai toan thilt k l kit cau, thilt k l he die'u khien, dan ddng cung nhfl xae dinh c b l dp lam viee hop ly eho thilt bi. Them vao do cd the dfla ra cae khuyen cao trong qua trinh khai thae van banh gdp phan nang eao nang suat va tudi thp eda thiet bi. Xuat phat td li do dd bai toan nghien cdu dpng lflc hpc thiet bi cat be tdng cdt thep (BTCT) tich hpp tren may xdc cd y nghia khoa hpc va tinh thde tien.
2. M 6 HINH D O N G L i r e H O C THIET BI CAT BE TONG COT THEP LAP TREN MAY XUC
Dac diem can tao eua to hpp (hinh 1):
I h i l t bi cat tich hpp ddpe lap the vao vi tri cua gau xdc bao gdm ed gia nang 3, can nang 4 va dia eat 5 lien kit vdi nhau bang khdp ban 11.
Tren gia nang sd 3 ddpe lap them mdt cum ca cau quay hfldng de da dang hfldng cat cua thiet bi So vdi may nguyen ban ban dau thi td hpp thiet bi cat can t h i m 01 xy lanh de nang ha can
nang, 01 md to thuy lflc quay hfldng va 01 md to quay dia cat.
Cac gia thilt sd dung de xay dflng md hinh ddng lflc hpc: May xdc va thiet bi cat BTCT la vat ran tuylt ddi dflpc dae trflng bdi 6 khau bao gdm: Khung gam-cabin; Can may; Tay can;
Gia nang; Can nang va dia cat. Mat phang lam viec cua thilt hi trung vdi mat phang ddi xdng cua may xdc; Vi tri lam viee eua may la nen dat bang phang, khdng biln dang trong qua trinh cat; Khdng van hanh he di ehuyin, ca c£u quay san quay eda may xue va eP cau quay hfldng dia cat trong qua trinh cat; Bd qua sfl dao ddng cua he thdng thuy lflc dan dpng thilt bi cdng tac va thiet bi cat trong qua trinh lam vile; Quy eae lflc dan ddng eua cae xy lanh thuy lflc thanh eac md men tai cae diera lien kit.
Hinh 1: Md hinh ddng lUe hgc thiit bi cdt
Md binh nghien cdu ddng ldc hpe qua trinh eat be tdng cdt thep cda thiet bi cat lap tren may xdc thuy lflc tren hinh 1: Md hinh dflpc xay dflng cho trfldng hpp may xue dang ddng yIn, gdm nam bac tfl do. Trpng tam cae khau: Khung gam-ea bin (I^, m^g); Can may xdc (Ij, m,g); tay can (I^, m^g); Gia thilt hi eat (I3, mjg); Can nang thilt hi eat (I^, m^g); DTa cat (I5, m^g) cd tpa dp trpng tam lan Iflpt la eae
d i e m C , , C , , C , , C , , C , v a C , . '^
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Lien ket gifla eac khau: Cac khau h l n kit vdi nhau bang khdp ban 11 O^ (khau 1 vdi khau 2), khdp ban le O^ (khau 2 vdi khau 3), khdp ban le O^ (khau 3 vdi khau 4); Khdp ban le O^ (khau 4 vdi khau 5).
Cac tpa dp suy rdng dde lap: De danh gia eac dac trflng ddng life hpe cua eP he, md hinh se xem xet cac chuyen dieh ed the eua eP he nhfl sau: q^- Gdc quay cda can may quanh dilm h l n ket O^; q^- Gdc quay cua tay can quanh dilm lien kit O^; q^- Gdc quay eua gia thilt hi cat quanh diem liln kit O^; q^- Gde quay eua can nang quanh diem liln kit O3; q^- Gde quay cua dla cat quanh diem liln k i t O^.
Cac md men dan dpng va life can dat lln CP he nhfl sau: M^ - Md men do xy lanh nang can gay ra; M^ - Md men do xy lanh tay can gSy ra; M^ - Md men do xy lanh quay gau gay ra; M^ - Md men do xy lanh dan hfldng gay ra; M^ - Md men do md to quay dia cat gay ra;
P^ - Tong cac thanh phan lflc can theo phflpng tilp tuyen; P^_^ - Tdng cac thanh phan lflc can theo phflpng phap tuyen.
may xue va thiet hi cat, ta gan vao eP he mdt he toa dp d l cac cd dinh O^pij^z^ co gdc O^, la khdp chan can, cae he toa dd OjX,y,Zj, O^x^y^z^, OjX^y^z^, O^x^y^z^ va O^x^y^z^ cd gdc g i n tai eac diem Uen kit gifla cac khau cua may va thilt bi eat (hinh 2). True quay cua eac k h i u nam ngang vudng gde vdi mat phang thang dflng. Vi tri eua mdi vat dflpc xae dinh bdi 4 thdng sd: Cac toa dp x^, y , z^ cua he toa dp vat ldc ban dau trong he Oj|Xpyj|Z|j va gdc xoay 9. gida cac truc O x v i
Ap dung phep bien dpi Denavit - Hartenberg de xac dinh m o hinh dpng hpc ciia tp hpp may xue - thiet bi cat.
Theo dp, vi^t t6ng quat dpng nang cho khau thli i nhu sau:
>n,(*f+y,')+i, i q i =1,2 5 (1)
The nang c i a khau thil i dupc tinh nhu sau:
^-m,S/.1^g^^ l,sin(2;qi) ksin(2q,); i=U,..,5 P )
Ap dung nguyen ly Lagrange Ipai 11 ta
dL 3q, v6i L=j](T,+U,)
T,(q,);i = l,2,...,5
(3)
Hinh 2: He true toa do gdn cho mdy xdc vd thiet hi cdt Tinh d?P ham thep ttIng bac tlJ dp cho phupng trinh 3 ta nhan diipc he phiipng trinh De quan sat chuyen dpng ciia cac cP cau chuyen dpng cua ca h0:
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<ii 12
Us.
+
* 1
* 2
_ * s .
+ h,
K
> 5 _
=
•Q;]
Q;
.%s.
Vdi ma tran khoi Iflpng (m..)5x5:
I ™.i = Z j "^ J Z ' . + Z ^ Z ^ lbl.cos I ^ q„.„,„^,,, j +1, ; khi i < j
[m,j = nij, khi i > j Vdi ma tran khdi Iflong (O )5xi:
1*, = g Z Z " ^ k l a C o s I ^ q , Vdi ma tran khdi Iflpng (h^)5xi:
h,=C,+tn,^
Cac gia tri C^ va n^ trong cdng thde (8) dflpc tinh nhfl sau:
^ . = Z E Z ^kkKl Z ^d sin X^«i^n(b,.) ^ i m m ( b , c ) < l k=i b=i c=l(c*i>
° , = - Z Z 2 ™i.M= Z 4 d sin X 1 W ™ M >*• m i n ( b , c ) > l
1„ k h i i = k 1, k h i i # k , Trong cac cpi^ thilc (6), (7), (8) va (9) can luu y:l,
(4)
(6)
(7)
(8)
(9)
(10)
Ve phai cua he phUPng trinh (4) dilpc xac dinh bang each tinh cpng kha di CLia cac liic khpng CO the, bao g6m liJc can cat va liic d i n ciia cac khau.
Q^rM,+P.[a,s,+a,s„+a,s,j,+a,s,„+l„,s„,„]-P^[a,c,+ajC,,+a,c,„+a,c,„+I„3C,„„]
Q[i =M, +P„ [a.s,, +a,s,,, +a,s,„ +l,„s,„,J -P^[a,c„+a,c„3 +a,c,„ +l,„c,„„,]
Q;, =Mj+P,. [a,s,,,+ii.s,„+lBnS,„55]-I',[''!',B+".':„„+1B„C,„„]
Qj,=M,+P„[a,s,,„+l,„s,„„]-P^[a,c„„+l,„c,„,J Q;,=M,+P„|l.„s,:,„]-P,[l„5':i2«iil
(11)
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3. THONG SO DAU VAO VA CAC KET QUA NHAN DUOC
May xiic thuy liic la may Solar 130W-V va thi^t bi cat tich hpp co cac thong so lien quan den cac he so trong he phUPng trinh (4): mj=3890,7kg; mj=1180,7kg; m,=498kg; m,=122,5kg;
mj=43,lkg; I,=5379,7kgm'; I,=498,3kgm=; l3=118,2kgm'; l,=19,2kgm'; I,=7,6kgm'; lj.,=2446mm;
lj=945mm; 1^3=1021mm; l^,=598mm; l;,,=300mm; a,=10°; 0^=3°; 03=4°; a^=7»; 05=45°. V) tri, van toe ban dau cua cac khau:
=[%'%'% ^% ^%]^i=[» ° ° ° '°°?^r
(12)Chia khoang thdi gian lam viec ciia thiet bi cat [0 T] thanh N khoang bang nhau, tien hanh giai he phiiong trinh (4) theo thuat toan sau:
BATDAU
1
M(q): ¥A. q):h Cq): Q* (q): N : T
T M i q ^ . q ^
i
.
1
h - A t - T . ' N
i
k:=0: t:=t,: q^ :_q^;q^:=q.
1
Tmii:MCq,):<K4,qaii{<i.);Q (q..)
i
Tirih: M-'(q^)
i
•E"!'q. = M""(qiX>"(q,)-M-'(q,)«:q, .q, ) - M * ( n )h(q,)
k=k+l Ssi
i
In q t ; q t ; q t
< d r tsN 7Z;i:>
\ Dung rfTTHUC
Hmh 3: Thudt todn gidi bdi todn ddng hgc lUc hge thiit bi cdt BTCT
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Khi v|n hanh eac khau din theo cac quy luat ddng hpc the hiln trong cae hinh 5,6,7 thi nhan dflpc quy dao dia cit nhfl hinh 4.
Do tfll quy fla
, ^ ,_
- ' - ^ r - - - -
dia cal
— ' - - t h l Ih2
---— / -
OS • - —
Hinh 4: Gdc quay vd quy dao cat cua dia cat
Gdc quay va quy dao tam cua dia cat trong khoang thdi gian khao sat T=15 giay nh^n dflpc dng vdi hai ehe dp cat: Cat eong (thl) va eat xien (th2). Tai thdi dilm t=0 dia cat da ehuyen ddng 6n dinh vdi tdc dd n=2000 (vdng/phut)=200Tt/3(rad/s), do vay khdng ed sfl khac bilt ve gde quay eua dia tai thdi diem t=15(giay) thi q5=4,6.10^(rad).
0-9 OB
1 0,7 06
„ .
~
Do Ihl chuyen « ( k h a
—^^"^^^"^
f
1)q1 thcot
— 1
•<
— t h l
—iw •
Do Ihl chuyen « (kliau 2) q2 IKeo t
..'^^-
— Ih2
---:
Do thl chuyen M (khau 3) q3 theo t Do Ihl chuyen w (khau 4) q4 theo t
i ^,,--
^^z:^ '
- - — I h l '
— — th2
''
~
0
, , , . . _ _ _ ^ H . i
^~~^^-"r~~~-^
— t h 2 '
- - - > ^
5 10 1
Hmh 5: Ket qud dich chuyen (qi,q^q^q) cua cdc khdu
D^ d^t dan dpng khSu cuoi theo quy dap thl va th2 thi can may chuyen dpng gipng nhau va *"q f = ""^if * 'hdi diem (tj=T) la 0,556(rad). Tuy nhien, cac khau con lai hoan toan khac: *'q„=5,33(rad) va *'q„=5,47(rad); *'q3=6,55(rad) va '"q3,=6,15(rad); *'q,,=4,32(rad) va ft!q^j=3,46 (rad).
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- — - t h l th2
- • : — - r " ^ - v ^
0.6
1
& 0,2 0
Do thl von toe (khau 2) qZ Iheo t
-^^
yj'''-' r
- - ^ • t h i
— t h 2 :
_ ^>^__.
-
Do thl « n to
,'
c (khau 3) q3
..- .
theot
Ih2
'-''
N ^ • ^ " - — i ; : ^ - — -thlIh2
~ ^ ^
Hinh 6: Ket qud vdn tdc (q ^%q ^cf .^,c() cda cdc khdu
Do thi gia toe (khau 1) q i ' theo t Do thl gia tac (khau 2] q ? thl
- . • — I h l
— • — t h 2
- ^ ^ ^ - T J - - ^
^'A
y \
- ' ^ ' '~~''^'*V^i
! 1 i •
- — - I h l
-A.^-
Do thl gia toe (khau 3) q3' theo t Do thi gia too (khau 4) q4' theo t
- — - t h l th2
••^
^^
/
•• '' y
^ ^ ^ ^ - . . '^—-
'" >M~-^
—"/'
- — • t h l th2
Hmh 7: Kit qud gia tdc {q\,q^'<i,'q) cua cdc khdu
Ket qua van toe (hinh 6) cho thay khi chuydn che dp cat thi may xue van hoat dpng 6 ch^
dp van tpc tUPng dpi pn dinh, chi khac ve bien dp thay dpi. Tuy nhien, ve gia toe thi so lan doi chieu cua gia toe vdi tat ca cac khau la 16n hon v6i che dp cat cong (hinh 7)
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5. KET LUAN
Bai bao da xay md hinh tdng quat de nghiin cdu dpng lflc hpc thiet hi cat, md hinh toan vdi 5 phflong trinh vi phan c&p 2 la ca sd de giai xac dinh eac dac trflng ddng lflc hpe cung nhfl lam CO sd cho bai toan dieu khien va van hanh hieu qua thiet bi theo c b l dp \km vile hpp ly
Cac ket qua tinh toan da lam rd quy luat ddng hpe cda cae khau dan de dat dflpc quy dao dia eat, cung nhfl nang suat (chieu dai vet eat) theo yeu cau.
Khi chuyen c h i dp cat td eat xien sang cat eong thi quy luat dich chuyen cda can may xue (khau 1) gan nhfl khong cd sfl thay ddi. Quy luat dich ehuyin, van toe va gia tde eua eac khdu 2, 3 va 4 ed mflc dp anh hfldng tang dan den quy dao cua khau cdng tac (dia cat), dilu nay the hiln d gia tri true tung eua cac do thi tang dan tfl khau 2 d i n khau 4.*>
Ngay nhan bai: 14/8/2014 Ngay phan biln: 12/9/2014
TM lieu tham khao:
[1]. Nguyen Khang (2007), Ddng lUc hgc he nhiiu vdt, NXB. Khoa hoc va Ky thu^t.
[2]. Vu Cdng Ham (2014), Cd hgc he nhiiu vdt, NXB. Quan dpi Nhan dan.
[3]. C. Y. Wang, Y. N. Hu, and H. N. Ding (2004), Cutting forces in Sawing Process cf Remforced Concrete, Guangdong University of Technology.
[4]. C. L. Nalezny (1971) Cutting rock or frozen soil with a circular saw. Journal of Terramechanics, Britain.
[5]. W Polini, S.Turchetta (2004), Force and specific energy in stone cutting by diamond mill. International Journal of Machine Tools & Manuafacture (44), Italy.
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