NGHIEN Ciiu - TRAO OOI ^/ Nghien cuiu kha nang hoat dong ciia xe chira chay riAig da nang khu rihig (*) TS DirONG VAN TAI TOM TAT Rdng la ngudn tai nguyen vd cung quy gia doi vdi moi quoc gia Song, dien tich rdng cang bisuy giam, ma m d t t r o n g nhdng nguyen nhan la chay rdng gay d V i e t Nam hang nam xay hang tram vu chay rdng, lam mat hang ngan rdng, gay thiet hai Idn ve kinh te va mdi trddng sinh thai Hien nay, cac thiet bi chda chay rdng d ndde ta rat han che nen viec dap tat cac dam chay rdng la khd khan De tai trgng diem cap nha ndde KC07.13/06-10 da thie't ke che tao raxe chda chay rdng da nang.Thiet bi da ddgc khao nghiem va cho thay hieu qua chda chay rdng cao Oe sd dung cd hieu qua va an toan xe chda chay rdng da nang thi can thiet phai nghien cdu kha nang hoat ddng cua xe chda chay rdng khu rdng khdng cd dddng Ket qua nghien cdu da thiet lap ddgc md hinh tinh toan, xay ddng ddgc phdong trinh can bang ldc theo dieu kien ldc keo va phdgng trinh can bang ldc theo dieu kien ldc ban Oa khao sat phdgng trinh can bang ldc theo dieu kien keo va ban va da xac dinh ddgc ddc dgc Idn nhat cua khu rdng khdng cd dddng ma xe chda chay rdng da nang cd the hoat ddng ddgc Ke't qua nghien cdu la eg sd khoa hgc de xac dinh dieu kien lam viec an toan va hieu qua cua xe chda chay khu rdng DAT VAN DE Xe chiia chay ning da nang duge thiet ke tren ca so tich hgp nhieu cdng nghe chira chay ning, vdi nhieu linh nang chira chay rimg tren mdt xe co so la xe td td Ural Nguyen ly boat ddng cua xe la cd dam chay rimg xay ra, xe se di chuyen den nai ed dam chay, sir dung he thong lam bang each ly de khoanh voing, cd lap each ly dam chay, su dung he thdng phun dat cat, nudc de dap lua Nhu vay la, boat ddng chira chay rimg, xe phai di dgng d khu rimg khdng cd dudng, vdi cac doe khae va nhieu vat can cua khu ning Vdi nhirng ly da trinh bay tren, chiing ldi lien hanh nghien ciru kha nang boat ddng cua xe khu ning DOI TUONG VA PHlTONG PHAP NGHIEN CLTU 2.1 Doi tuang vd thiet hi nghien cuu Ddi tugng nguyen ciru la mdt sd khu rung ed nguy CO chay eao, thiet bi nghien ciru la xe chiia chay rimg da nang de lai KC07.13/06-10 thiet ke che lao 2.2 Phuang phdp nghien cuu Phuang phap nghien ciru duge su dung la ap dung ly thuyet d td may keo de xay dung md hinh va thiet lap phuang trinh can bang lire theo dieu kien keo va ban, khao sat phuang trinh lap dugc de xac dinh dugc ddc ldn nhat xe cd boat dgng dugc khu rung (*) Khoa Co dien va Cong trinh - Trm'mg Dai hoc Lam nghiep khdng cd dudng TAP CHi C a KHi VIET NAM V c^ So - Tliang nam 2011 NGHIEN ciiu-TRAOOOI KET QUA VA THAO LUAN 3.1 Cdc luc tdc dung len xe chira chdy rimg da ndng hogt dpng chira chdy rimg (1) FKI + FK + FK3 = G.sina + F„ + F , , + F^, + Trong dd; F^.^ ; F^.^ ; ¥^^ - luc keo a cac banh chu ddng cua xe Xet trudng hgp long quat xe dang chay tren khu ning vdi ddc g vdi van tde v khdng ddi, dong thdi, he thdng cat cay phia trudc, he thdng phay ed rac lam bang trang each ly dam chay a phia sau van hoat ddng, tren xe cd ehd day nudc Sa luc tae dung len xe dugc the hien tren hinh Fj^j ; FQ^ ; FQJ - lire can lan a eac banh xe F^j - lue can he thdng cat cay d trudc xe Fj,, - luc can he thdng eat co rac gay F^ - luc can dudng vdng F J • lue can quan tinh a) Tinh luc keo (FJ: Tacd;F^, + F , , + F , , = F , Trong dd, F^ la lue keo tiep luyen cua cac banh xe ehu dgng, N Ddi vdl xe chiia chay rimg da nang, tat ea eac banh xe deu la banh chii ddng, nen F^ ehinh la liie keo ddng ca sinh I linh 1: So luc tac dung len xe kin xe hoat dong chua cha\ rimg - Trgng lugng eua xe bao gdm cac bd phan edng lite, nudc a tren xe va loan bd tai trgng cua xe; ky hieu G dat tai trgng tam eua xe va dugc phan lam phan; Trong dd; M^ - Md men quay eua cac banh xe ehu ddng, N.m G = G.eosa va G = G.sina z X - Tai eac diem tiep xiic giiia banh xe vdi mat dudng cd lire keo tiep tuyen Fj.j, F^,,, F^^ dat tai cae banh ehu ddng va cd liic can lan F^j, F^.,, F^^ ciing dat lai cac banh chu dgng - Tai true cua banh xc ed mdmen chu ddng tir dgng ca truyen den M,, M, M^ - Tai diem tiep xuc cua banh xe vdi mat dudng cd phan luc phap luyen N^, N„ N,, va mdmen can lan m^, m„ m,, ngugc chieu vdi mdmen ehu dgng M,, M,, M, r^^ - Ban kinh lam viee cua banh xe ehu ddng Trong dd; A - He sd bien dang banh xe r bx- Ban kinh eua banh xe chu dgng, m Mdmen quay cua cae banh xe ehu ddng dugc tinh nhu sau; - Ggi Itrc cat cay va day cay cua he thdng cat cay la F^j, luc can cua he thdng phay dat lam sach cd rac phia sau xe la F^^^ M^=M.i^.ip.i„.T1 Trong dd; M - Md men quay cue dai d dau tnic ca ij - Ty sd truyen ciia hop sd chinh - Ggi luc can quan dnh xe ehuyen ddng tinh rien va cae ebuy en ddng quay cua xe la F ^ ij, - Ty sd truyen d hop sd phu - Do xe chuyen ddng vdi van lde van tde thap nen bo qua luc can cua khdng T| - Hieu suat bd truyen lire 3.2 Phuang trinh chuyen dpng ciia xe hogt dpng chira chdy rUng tinh theo luc keo Chieu cac luc lac diing len xe theo true X Ta cd phuang trinh can bang luc keo ig - Ty sd truyen a cau chu dgng b) Tinh luc cdn ldn (FJ: - Ta ed; (3) F^„ + F^^ + F^, = F^ Trong dd; F^ - Lue can lan, N Luc can lan dugc dnh nhu sau; (4)F =G.f n TAP CHi c a KHi VIET NAM *** So - Thang nam 2011 NGHIEN Ciiu • TRAO OOI Trong dd; f - He sd can lan giira banh xe vdi mat dat rimg he sd phu thude \ao trang thai be mat dat rimg G - Trgng lugng loan bd xe, N o ol z - Sd rang tham gia vao qua trinh c^t U - Van ldc day cua vao cay m/s - Lue day Q dugc tinh nhu sau; - Trong do: f - He so can lan ca ban '-^ h - Chieu day ludi cat ol Kj - He so tinh den ldi ldm, map md cua mat dat rimg K., - He sd tinh den tham mue, ed khd, la khd d tren be mat dat rimg Kj - He sd tinh den chudng ngai vat nhu gdc cay, cay nam chan ngang, ranh nudc chay K^ - He sd linh den trang thai cua ldp xe vdi be mat dat rimg c) Luc cdn cdt F^^ duac tinh nhu sau: Trong qua trinh cat bang ludi cua dia, luc ck P,, ed phuang theo ldc cat, phan lire day Q ed phuong vudng gdc vdi lire eat Theo lai lieu [1] luc da\ Q = (0,2 -0,7)P, Nhu vay, luc day cua vao gd dugc tinh theo edng thirc; (6) Q = 0,5.P^ Tuy theo vi tri ciia ludi cat so vdi true cua cay ggi la gdc gap thd cp, gdc gap thd bien ddi tir - 90" - Trong trudng hgp gdc (p < 90°, la cd lue eat va lire day dugc linh theo cdng thirc sau; Theo nguyen ly cat ggt gd [1], he thdng cat cay thi sinh luc cat P^ va lire day Q Qua trinh cat cay duac the hien tren so hinh 5„ =Psina ±gcosa - Trudng hgp mat phang cua dia cua vudng gdc vdi thd gd (true than cay), luc cat va lire day dugc tinh theo cdng thirc sau; (7)- - Nhu vay lue can cat he thdng cat cay d dau xe tao duoc linh nhu sau; (8) Pc, 0,5.P^ n Trong dd; P^ Luc cat eua dia cua dugc linb theo cdng thirc (5) n - Sd dia cua ciing tham gia vao qua trinh cat d) Tinh luc cdn he thong phay co rdc P^,, Hinh 2: So tinh toan luc cat va luc day ciia he thong chat cay - Luc cat ciia ludi cua dugc tinh theo cdng thirc; (5)P^ = k.b.h.zU Trong dd; P^^, - Luc cat cua dia cua k - He sd can cat rieng b - Chicu rdng mach cat b = D, (D - dudng kinh cay) Trong qua trinh boat dgng, phay cd rac lao bang trang each ly, he thdng phay eo rac vira ehuyen dgng quay, vira chuyen dgng tinh lien ciing vdi van tdc cua xe Cac dao eJl dat ehuyen ddng quay Iron xung quanh true cua dao, edt dat theo nguy en ly cat dat o dang bua Nguyen ly cit dat a dang biia cd uu diem ldn nhat dd la gap goc cay, md da canh cay dao eat lu trugt qua, khdng lam tang lue cat khdng anh huong den luc can eat So tinh loan luc cat a dang bua dugc the hicn tren hinh ^ TAP CHi c a KHi VIET NAM *l* So - Tliang nam 2011 NGHIEN ciiu-TRAOOOI (13) F - GxC^ R Trong dd; C - he sd can dudng vdng R - ban kinh dudng \ dng f) Tinh luc cdn qudn tinh Huih 3: So tinh toan lire cat cy dang biia - Luc can he thdng cat co rac lam bang each ly duge tinh nhu sau; Liie can quan tinh cua xe bao gdm lue can quan tinh ebuy en ddng linh lien cua xe va lire can quan linh cae bd phan chuyen dgng quay, lire can quan linh cd the linh gan dung nhu sau; ^ ^ G dv (14)F,,=6-— S dt ^ (9) P^, = P , + P + q s i n a ^ ^ Cj cd ce Trong dd; V - van tdc ehuyen ddng cua xe T Trong dd; P^^ - Lire cat dat cua dao cat P^i - Luc can lan cua he thdng lam sach co rac q - Trgng lugng cua he thdng lam sach co rae - Luc cat dat P ^ duac linh nhu sau; cd Theo nguyen ly cat dat a dang bua [3], lire eat xung luc va cham cua dao cat lao dugc linh nhu sau; (10)p -^Jkzllj = + ai^ ã Đ j^e JQ- a he sd; i^^ - ly sd truy en g) Phuang trinh tong qudt xe chira chdy rimg hogt dpng chira chdy a khu rirng Thay eac edng thirc (2); (4); (8); (12); (13) va (14) vao cdng thirc (1) ta cd; (15)^ ^(VtZ)f^^(N) I ^gM t Trong dd; R,, - Ban kinh eua dia dao, m - Chieu dai cao cat, m Jpj - Md men quan linh dao eat, kgmco - Van tde gdc eiia dao eat dat va co rae, 1/s t - Thdi gian va cham gidy m - Sd dao cat cimg tham gia vao qua trinh cat - Luc cai) lan (P^^) dugc linh nhu sau; GxC, G dv R g dl -^—.J„,.o).—° ^ +qfi JgM Nhan xet: Tii' phuang trinh ebuy en ddng cua xe chira chay rimg linh theo lire keo theo cdng Ihire (15), chiing ldi cd nhan xet sau; - Kha nang di dgng eua xe d id phu thudc vao nhieu yeu id anh huong, dd la; + Do ddc cua khu ning (a) g - Gia lde trgng trudng, m/sM- Do lun eua nen dat sau va cham mm •- {G + q).s\na + G/„ + 0.5P,n + + He sd can lan giira banh xe vdi mat dat rirng (fj + Dudng kinh cay can cat, sd ludi cua tham gia vao qua trinh cat + Trgng lugng eiia he thdng eat cd rae, trgng lugng ciia loan bd xe dtd (ll)P,=*q.f, + Luc can he thdng cat eo rac lam bang each Trong dd; q - Trgng lugng cua he thdng, TV^ fi - He sd can lan cua he thdng vdi mat dat rimg Thay edng thirc (10) va (11) vao edng thirc (9) la cd edng thuc linh luc can he thdng eat co rac nhu sau; (12)^C2= m[R,-l) " 'y" o .rc o ( ^ ° " ^ ' " —J - De xae dinh dugc mirc anh huang cua cac yeu td chiing la phai khao sal phuang trinh (15) d mgt so trudng hgp nhat dinh - Tir phuang trinh (15) chiing la cd the xae dinh ^,+^.sina bang ly thuy el dugc gdc a, tii dd cd the xac dinh dugc e) Tinh luc can xe ehgy tren ducmg vong Trong qua trinh xe chira chay rimg boat dgng, xe phai quay vdng qui trinh xe quay vdng sinh lue can cd su xe dich quy dao chuyen ddng eua banh trudc va banh sau luc can quay vdng duge tinh theo edng thuc sau; xe ed the di ebuy en dugc a ddc bao nhieu 3.3 Xdc dinh khd ndng di dpng cua xe theo dieu kien bdm De cho xe ebuy en ddng duge, ngoai dieu kien luc keo cdn phai thoa man dieu kien lire ban de xe khong bi trugt ! H TAP CHi c a KHi VIET NAM V So - Thang nam 2011 NGHIEN Ciiu - TRAO OOI (16)F, a = arcsinO,32 = 18°39' Nhu vay, tinh theo ly thuyet, xe cho 5,lm-^ nude, vira eat cay, vira cat co lao bang each h , dong thdi chuyen dgng a tren dia hinh khdng cd dudng ung ddc dgc a xe cd the di ehuyen dugc vdi doc dgc eua dia hinh la a = 18°39\ b) Tinh theo dieu kien luc bdn F, ' * b Tuang lu nhu phan tinh theo luc keo, bai loan khao sal vdi cac sd lieu nhu phan tinh theo lue keo dd, he sd bam dugc lay tuang tu nhu he so bam cua xe dtd van ehuyen gd di chuyen ning |r = 0,55 r G dv r^ + R 0,55 g dt Nhan xet: Tir phuang trinh (18) la cd the xac dinh dugc ddc ma xe cd the di ddng duge linh theo dieu kien lire bam 3.4 Khdo sdt khd ndng di dpng cda xe hogt dpng chira chdy rung khu rimg • Dc khao sat kha nang di ddng ciia xe Ireit dudng vdi ddc, chiing la phai xac dinh duge eac be so phuang trinh (2) va (4) Viec xac dinh cac he so bang ly thuyet la rat phiic lap Trong nghien ciru nay, chiing tdi su dung phuang phap thuc nghiem va tham khao cae lai lieii, cac sd lieu da dugc edng bd, tii' dd, chgn dugc mdt gia tri thich hgp va phii hgp vdi bai loan dat a) Tinh theo dieu kien luc keo F^ Bai loan duge khao sal vdi cac sd lieu sau; - - Trgng lugng loan bd xe G = 170.000 N (ed ca nudc) - Mdmen dau tnic ca M = 667 N m - He sd can lan giiia banh xe va mat dat rimg fj, = 0.3 - He so can lan giira he thdng cat eo rac vdi mat dat f, = 0,3 - Dudng kinh cay cat D = 25 em - Trgng lugng cua he thong cat cd rac q = 5.000 N - So vdng quay cua trdng dao = 800 vdng/phiil - He sd can cat rieng ciia go k = 11,79 Kg/mm- Nhu vay, khao sat theo dieu kien lue bam hoat ddng chira chay a khu ning xe cd the di dgng duge a ddc dgc a = 16"8' KET LUAN Bang cae nghien cuu ly thuyet d Id may keo, da xay dung dugc so dd tinh loan luc tac dung len xe chiia chay rirng da nang boat ddng chira chay rimg, tir dd, da thiet lap dugc phuang trinh can bang lue theo dieu kien luc keo (14) va lire bam (17) Da khao sal phuang trinh can bang luc keo va bam, tir dd, xac dinh dugc ddc dgc ldn nhat ma xe chira chay rimg da nang cd the boat ddng dugc khu rimg khdng cd dudng, cac he thdng tren xe ciing boat ddng la a = 16°8' • Tai lieu tham khao: Hoang Htru Ngu>'en (2008), Mdy vd thiet bi che bien gd, Ttdp I, NXB Nong nghiep, Ha Npi Nguyen Quang (1983) ! an chuyen gd bdng dirdng d td, NXB - So ludi cua tham gia ddng thdi eiing cat la m = - Ban kinh dTa tljcp R„ = 20cm, = 12 cm Thay tat ca cae gia In vao edng thiic (18), sau tinh loan la xac dinh dugc gdc a nhu sau; Sina = 0,278 => a = arcsin0,278 = 16"8' Nong nghiep Ha Noi Do Sanh (1999), Co hoc tap 1, Tap NXB (uao due Duong Van Tai (2010), Bao cao ket qua de lai Uong diem cap nha nuoc, "Nghien ciru cdng nghe vd ihiet ke che tgo cdc lliiel bi chuyen dung chiia chdy rimg'', ma so KC07.13/06-10, Cue ITiong lin Khoa hpc & Cong nghe Quoc gia Ha Noi TAP CHi c a KHi VIET NAM V So - Tliang nam 2011 ... len xe kin xe hoat dong chua cha\ rimg - Trgng lugng eua xe bao gdm cac bd phan edng lite, nudc a tren xe va loan bd tai trgng cua xe; ky hieu G dat tai trgng tam eua xe va dugc phan lam phan; Trong. .. xac dinh dugc e) Tinh luc can xe ehgy tren ducmg vong Trong qua trinh xe chira chay rimg boat dgng, xe phai quay vdng qui trinh xe quay vdng sinh lue can cd su xe dich quy dao chuyen ddng eua... Ddi vdi xe did cd tat ca eac banh xe dSu la banh chu ddng tbi lye bam duge xac dinh theo edng thirc sau; (17) F, = G.^ Trong dd; G - Trgng lugng toan bd xe TV |a - He sd bam eua banh xe vdi mat