NGHIEN CUfU - TRAO DOI T | [y\J HOA THIET KE KHUNG THAN MAY XE LlfQI CAO TOC BANG PHUONG PHAP MO M N G S OPTIMIZATION DESIGN FOR BODY FRAME OF EXPANDED MACHINE BASED ON NUMERICAL SIMULATION Pham Van Nghe, Le Trung Kien, Vii Thanh Hai Truang Dai hgc Bach Khoa Ha Ngi TOM TAT Thiit ki mdy ca Ian su dving kit cdu ca Id c6ng viec doi hoi phai tieu ton nhieu thai gian y c6ng sice Di co thi gidm thiiu nhitng chi phi kh6ng cdn thiet thi can phai dp dung cdc ky thuat tien tiin qud trinh tinh todn vd thiit ki Di tdng cuang cimg khung thdn mdy, cdn thietphdi tinh todn gidm biin dgng Ian nhdt bdng tii im kit cdu khung mdy Bdi bdo trinh bay nhitng nguyen tdc ti todn thiit ki dua tren ca sa m6 phong si qud trinh bien dgng khung thdn thiet ke mdy xe luai Sau phdn tich vd toi uu hoa thiit ki khung thdn cua mdy xe luai, cung vd ben cua mdy dugc dam bdo r, r r Tir khoa: Mdy xe luai; Khung mdy; ung sudt; Bien dgng, ABSTRACT Frame Mechanical Press designing involves to spend a lot of time and effort To reduce the unnecessary cost, it is necessary to put the advanced technique into calculation and design process In order to enhance the body frame rigidity, it is necessary to reduce the maximum body frame deformation by optimizing the body frame structure Presenting the separate principles when designing bodyframeof machine basing on numerical simulation results of deformation process for expanded machine is the aim of the paper After the performance analysis of the optimized designed body frame of expanded machine, its rigidity and strength are proved Keywords: Expanded metal machine; Frame; Stress; Strain, I TAP CHI CO KHI VIET NAM, Sl nam 2014 www.cokhivietnam.vn NGHIEN CUfU - TRAO Q6\ DAT VAN DE phu thugc vao cac ylu t6 sau: Hien nay, cac may ep ca Ian dan dgng co - Luc ep danh nghia: Xac dinh ciing SU dung cac nganh c6ng nghiep a Viet ciia may; Nam chii yeu van dugc nhap ve tir cac hang san - Kich thuac dung cu: Anh huomg den xuat may Ian nhu: Sertom (Italia); Nieland (Ita- kich thuac gia c6ng; - Kich thuac khoang kh6ng gian lam viec ha); Sicmi (Italia); Hefei (Trung Qulc) Vi?c thiet ke khung than cac may dua tren ca sa may: Xac dinh hinh dang khung than may; - Do chinh xac dan huang: Anh huang ca m6 phong s6 qua trinh bien dang la mgt ITnh vuc kha mai me a nuac ta, chiing ta chii ylu vin ve hinh dang va ciing khung than may r r can cii vao kinh nghiem, sau hoan chinh thilt Voi cac khung than may co luc ep danh ke se thuc hien che tao may vai he s6 ben cao nghia nho ban 2500 kN, khung may thuang co ke Dieu se kh6ng tranh khoi nhiing tin that vl cau - chu: C Neu may co luc ep danh nghia Ian kinh te ciing nhu thai gian Bai vay, viec nghien thuang dugc thiet ke dang than km (hinh 2) Cac ciiu va trinh bay nhiing nguyen tac ciing nhu ky bien dang khung than may tiiy theo ket cau ciing thuat thiet ke khung than may ep tren co so m6 dugc tinh toan khac (hinh 3) phong s6 qua trinh bien dang la bet siic can thiet Hinh la ket cau t6ng the cua may xe luai luc ep danh nghia 120 tan voi khung than dang ban Khung than may mang dau trugt chuyen dgng se hi bien dang qua trinh gia c6ng th6ng qua he th6ng true truyen tac dung luc true tiep len cac g6i tren khung Giai ban bien dang Ion nhat Hinh 2: Ket cdu thdn T^.dy dgng vd kin cua khung may la 1.2 mm Vat lieu lam khung la thep 45 CO giai ban dan h6i a^ = 360 MPa, giai ban ben o = 610 Mpa, qua trinh tinh toan T va thiet ke can thiet bien dang t6ng va ling suat tuang duong nho ban cac gia tri giai han r r Hinh 3: Cdc kieu Men dgng khung mdy theo kit cdu Hinh 1: Tdng the mdy xe luoi cao t6c Khung may la chi tiet Ian hap thu lire ciia may ep Khung may giiip cho diu trugt, dan huang va cac bg phan din dgng cho may chuyen dgng chinh xac Thiet ke cau tnic khung than may Khung may xe luai voi dac diem luc ep danh nghia kh6ng Ion, nhien, ket ciu dung cu gia c6ng Ian, khoang kh6ng lam viec rgng nen thiet ke can lira chgn ket cau khung may dang kin Vai dieu kien san xuat tai Viet Nam, lua chgn phuang an che tao khung may xe luoi tu thep ban Viec sii dung than may ban se giam nhe khIi lugng than may, tang ciing so vai than may che tao bang gang diic, thay the mgt phan hoac hoan toan thep diic hiem bang cac tam thep va cac vat diic bang thep co kh6i lugng nho ban, tang tinh gia c6ng dieu kien gia c6ng ca ^ ban che TAP CHI CO KHI VIET NAM, S6 nam 2014 www.cokhivietnam.vn NGHIEN CUfU-TRAO 061 CO Sd TINH TOAN KHUNG MAY BANG Hien nay, dii voi loai khung thuang dung PHU^ONG PHAP GIAI TICH nhit, ta tinh cac tri sl m6men tai cac diem dac trung ciia no (bo qua tai trgng diing tam tac dung Tinh toan khung than may dugc tinh theo len bg phan din huang) Hinh thi hien cac hi sl hai phuang phap: m6men tai cac diem dac trung d6i vai mgt nhirng so d6 ph6 bien nhat: - Phuang phap m6 phong s6: Sii dung phuang phap phan tir huu ban vai cac phan mem h^.v -h^.v -h_ Caches6: (^-Y''^^^~Y'^^^~1 m6 phong chuyen dung de tinh toan cac gia tri ling suat, chuyen vi tai ban cho khung than may Cac m6 men dugc tinh bang c6ng thiic: tir lua chgn ket cau t6i uu - Phuong phap truyen th6ng sii dung giai tich: Do than may la ket phiic tap bao g6m cac phan hinh dang khac va tiet dien ngang thay d6i, vi the, kh6ng biet dugc he s6 kich thuac tuyet d6i eva he s6 tap trung ling suat k va k^ nen kh6ng tinh than may theo siic ben moi ma thuong tinh theo siic ben tinh va tinh ciing Khi he s6 an toan r^ thuang lay bang 10 d6i voi than may bang gang, n^, = ^ d6i vai thep diic va Oj, = 2,5 -^ d6i voi thep ban So di he s6 an toan lay Ian Nhu vay, mgt mat de tranh hong chi tilt dit tiln qua tai kh6ng co co cau bao hilm, bu lai su phan b6 ]di6ng ding diu luc dat vao than may mat khac de dam bao ciing cin thilt cua than may 3.P.L, - a K j j P c | - - —I-8M, \ \2) 8(2a.K3^ + ) M, ' PL M, + M , - - P c M, = M, a M, = M +-.P.C 3.Pa, -4c M,= ry -(r0-. > •JO g[{2a.K,,+3X3J:„+2a)-a=.K„] Sau xac dinh cac tilt dien nguy hilm Khi m6 hinh tinh toan than may la dang va ling suit tai iTng suit a tru ben cua khung khung, ta ve so d6 than may a dang khung a hai tinh theo c6ng thiic: hinh chieu: d6i vai than may thing diing dang A ± Mi + M^ chieu diing va chieu canh Tren so dl ve tai 2.L 2F Iv trgng tac dung len than may Da sl cac may ep tai h-gng tac dung len ban may coi la tai trgng phan b6 diu tren chilu dai C = 2L/3 (L la khoang each Trong do: giiia cac duong hric cua tru may) Nhiing luc tac - P: Luc danh nghia ciia may; dung len bg phan din huang tai trgng ciia diu - M.: M6men uln a bilu dl m6men uln cua trugt thuang bo qua [1] khung; - M^ = P Lj 2: M6men a mat phing vu6ng goc voi JiJmat phang ciia khung; - Lj 2: Khoang each hi duong tac dung luc P din mat phang qua trgng tam tru tuang ling; v - F: Dien tich tiet dien ngang nguy hilm tru; - ly, I^: M6men quan tinh ciia tilt dien nguy hilm ciia tru tuang ling d6i vai fruc y, x di qua trgng tam tiet dien, Hinh 4: Sa dgng khung ciia thdn mdy - h^, h : Khoang each tir tha ngoai cung cua tilt " , ^ Z "j ij.fj TAP CHI CO KHI VIET NAM, Sl nam 2014 www.cokhivietnam.vn NGHIEN CUfU-TRAO DOI dien din true trung boa x, y M6 hinh dugc thilt kl dang khung hop vai ket cau ban Qua trinh m6 phong s6 nham Do bien dang theo phuang tac dung luc muc dich tli uu cac kich thuac hinh hgc tir tilt tim dugc hi bilu thiic: Idem vat lieu 5, = ^ ^ [ p x , - ( M , - M , x J - J ^ + ^ : ^ + ^ ^ 48EJ 2E.Fj G.Fj Ta su dung m6 hinh vat lieu la thep CT3 dang tam vai cac th6ng s6 nhu sau: Trong do: K = 1,2: d6i vai tiet dien hinh chir nhat; K = 1,7 -^ 2: vai tiet dien hinh chii nhat rong 3.2 Mo hinh vat lieu G.F3 Gioi ban dan hIi a ,(MPa) 220 - 240 Gioi han ben a, (MPa) 380-470 Do dan dai tuong doi 6% 25-21 TINH TOAN KHUNG MAY BANG Ta tien hanh kiem nghiem ben ciia PHU^ONG PHAP M O PHONG SO khung may dua tren nhung tieu chuan ve ling suat 3.1 Xay dimg mo hinh hinh hoc sau: r r - Ung suat tuang duong von-Mises cho M6 hinh hinh hgc khung may ep bao g6m phep: [ a j < a/1.5 = 220/1.5 = 146 (MPa) hai vach ben, xa tren, xa dual dugc xay dung dua tren yeu cau chinh xac ve hinh dang va kich - Ung suat cho phep Ian nhat: [