Cơ sở tính toán hệ thống cắt đất của máy phun đất cát chữa cháy rừng

KHOA HOC - CONG NGHE CO SOTiNH TOAN HE THONG CAT DAT CUA MAY PHUN OAT CAT CHJJfA CHAY RUfNG Nguyen Vdn Qudn ', Duang Vdn Tdi" TOMTAT Dgc diim cda may phun dat cdt chOa chdy rung Id cat ddt vd hiit ddt tgi chd de phun vdo ddm chdy vi vgy he thdng cdt ddt tren mdy phun ddt cdt chira chay rimg dirac thiet ke theo nguyen ly cdt dgng bua de cat phdi da ri cdy thi dpng ca khdn^ hi qud tdi ddng thdi dgng cat ndy cho tieu hao cdng sudt nhd Bdi hdo ndy gidi thieu ca sd tinh todn he thdng cdt ddt a dgng bua hao gdm: Nguyen ly cat dat dgng bua dpng lire hoc cua qud trinh cdt, lire cdt ddt Ket qud nghien cuu dd dirge img dung de tinh todn thief ke che tgo may phun ddt cdt chira chdy rimg Tirlfhod: Cdt ddt dgng bua: Luc cdt ddt; Mdy phun ddt cat: Mdy phun ddt chira chdy rimg FUNDAMENTALS FOR CALCULATING SOIL CUTTING SYSTEM OF OF SOIL AND SAND SPRAYING MACHINE FOR FOREST FIRE FIGHTING Nguyen Van Quan ', Duong Van Tai' SUMMARY Soil and sand spraying machine used for forest fire fighting has the characteristics of cutting and intaking soil on the spot to spray on the fire Soil cutting system mounted on the machine are designed based on the principle of hammer type cutting, thus preventing the machine from overloading when the hammers meet stone or roots In addition, this type of cutting has low power consumption This article introduces a basis for calculating the hamme i)pe cutting system including: the principle of hammer type cutting; the dynamics of the cutting process and soil cutting forces The study results have been applied for calculating and developing the soil and sand spraying machine used for forest fire fighting Keyivords; hammer type cutting; soil cutting forces; soil spraying machine; forest fire fighting machine I DAT VAN DE chay, viec cat dat tai cho khu rimg rat phiic Viet nam hang nam van xay hang tram tap vi dat khu rimg thuang co lan da, re vu chay rirng, da lam mat hang ngan rung, cay, tir co the lam cho dpng ca hi qua tai De thiet hai ve kinh te hang tram t> d6ng, anh gia quyet van de de tai da nghien cim he huang xau den moi truang sinh thai Hien thong cat dat theo nguyen ly cat a dang bua de thiet bi chua chay rimg ban che, hieu qua ap dung vao thiet ke che tao cho he thong cat dat chua chay rimg rat thap ciia may phun dat cat chiia chay rimg De tai u-png diem cap nha nuoc "Nghien 11 DOI TUONG VA PHUONG PHAP NGHIEN ClTU cim cong nghe va thiet ke che tao cac thilt hi chuyen dung chira chay rimg", ma s6 KC07.13/06-10, da thidt k6 ch^ tao may phun dat cat chiia chay rijmg Kit qua thuc nghiem cho thay nang suat va hieu qua chu-a chay rimg cao, may da duoc cdp bang dgc quyen giai phap hihi i'ch so 936 2.1 €)6i tuong va thiet bi nghien eihi Doi tugng nguyen ciiu la dat rimg noi thuang xuyen xdy chay rimg, thiet bj nghien ciru la he thong cat d4t cua may phun dat cat chua chay rimg d l tai trgng dilm cip nha nuoc KCO? 13/06-10 thilt k l chl tao Dac dilm cua may phun ddt cat chiia chay rimg la cat dat, hut dat tai cho d l phun vao dam 2.2 P h u o n g p h a p nghien ciiu Phuang phap nghien cim dugc sii dung la ap dung 1> thuylt va cham co hgc de lap mo ' TS Tnrdng Dai hpc Um nghiep " PGS.TS Trudng Dai hpc L^m nghiep 22 -fS- ^5J-r / TAP CHi CONG NGHIEP NONG THON - SO 12 - 2014 KHOA HOC - CONG NGHE hinh tinh toan lire cat, thilt lap phuang ttinh dgng luc hgc cua dao cat dit, tinh toan lire cat ddt III KET QUA VA THAO LUAN 3.1 So cau tao cua he thdng cit d^t dang biia So dgng hgc cua he thdng cit ddt dang biia dugc the hien tren hinh tuang doi xung quanh diem 0| tam 0| chuyen dgng theo den diem Oi Do vay, dao cat di chu>en theo, nhung miii cat cam sau xuong dat \ a lire can cua dat, khap quay a OT nen mui dao cat diing yen, than dao cat di chuyen Mo men quay tai O4, canh tay don chinh lit chieu dai dao cat, luc tao mo men la luc F dia thep tao ra, luc co tac dung bay thoi dat da cat khoi nen dat Qua trinh bay dat dugc the hien a hinh 2a (qua trinh cat \ a bay dat tuang tu nhu cuoc dat bang thii cong) Hinh Cdu tgo cum bp phdn gieo I Dia thep: Dao cai: LirO'i dao u^t Cau tao he thong cat rat dan gian bao g6m mgt dia thep co duang kinh giiia hai true dl lap dao la D DTa thep lap tren mgt true, true nhan chuyen dgng quay tir dgng ca qua bg truyen hoac noi true tiep Tren dia thep co gdn true dl lap dao cat, co the lap 2,4,6 dao cat theo Dao cat chuyen dgng tucmg doi xung quanh diem 0| Tren dTa thep c6 lap luoi cat co cac thong so: a - goc sau; p - goc mai; 5- goc cat 3.2 Nguyen Iy cat dat ff dang bua Dua vao cau tao va chuyen dgng cua he thong, qua trinh cat dat dugc chia giai doan sau: - Giai doan 1: Dao cat chuyen dgng tren khong chua tiep xiic vai dat; luc ly tam nen phuang cua dao cat trimg voi duong kinh di qua hai true lap dao Dao cat chuyen dong quanh diem vcri so vong quay n van toe goc (0, dao cat du trii" mgt dgng nang lan (hinhl) - Giai doan 2: Dao cat tiep xuc vai dat (cat dat) cho dao cat tiep xiic voi dat vai dgng nang lan tai miii dao xay xung lire va cham lon Vai ket cau mQi dao co sac nhat dinh thai gian va cham ngan nen lire cat rat lan, miii dao se cam sau vao dat (hinh 2a) - Giai doan 3: Bay va tach dat: sau luai cat cam sau vao dat Liic dao cat quay Hlnh Nguyen ly cdt ddt dgng bua - Giai doan 4: Keo ddt Khi dilm O2 di chuyen den O3 theo quan he dgng hgc thi dao cat chuyen dgng tinh tien, qua tt-inh chuyen dgng dao cat keo theo lugng ddt may vira tao Nhu vay, dat sau cat dugc dua len mieng ho (hinh 2b) - Giai doan 5: Tung dat Sau klii keo dat khoi cho cat mgt so it dat nam a mat cua luai cat chuyen dgng cung vai luoi cat din mgt quy dao nhat dinh thi ddt vang khoi luoi cdt chuyin dong theo quan tinh va rai xuong Nhu vay dat dugc cat va tung len rat thuan lgi cho qua trinli hut de phun dat vao dam chay de dap liia TCr qua trinh phan tich nguyen ly cdt ddt dang biia a tren co mgt so nhan xet sau: - Lgi dung dugc dgng nang ciia dao cdt tao xung luc Ian de pha va kit cdu ciia ddt Tir chi phi nang Iugng rieng cho qua trinh cdt la rat thap dan den nguon dgng lire khong can phai co cong suat lan nen giam trgng lugng cua thiet bi va tang nang sudt ciia may - Lgi dung dugc canh tay don cua dao cdt dl ba\ dat nen t6n rat it luc Mat khac ciing lgi dung dugc img sudt tach rdt nho ciia ddt dl tach thoi dat khoi nen ddt (giai doan bdy va tach ddt) TAP CHI CONG NGHIEP NONG THON - SO 12 - 2014 23 KHOA H O C - CONG N G H E - Khi gap da, gap r l ca\' goc cay thi luc cat tang len dot nggt Neu luc cat dao cat tao nho han lire can cat thi dao cat khong an vao dat, nhung dao cat chuyen dgng quay quanh diem 0| nen cong suat cong suat cua dgng ca khong anh huang Day la dac diem quan trgng ciia phuong phap cat dat dang bua, no da giai quyet dugc kho khan lon nhat viec cat dat lam nghiep la thich hgp vai cac loai dat nhieu da, nhieu goc cay, re cay Con doi vai cac dang cat khac neu gap da, goc cay thi dgng co qua tai dan den hong he thong cat, hoac hong dgng CO 3.3 Dong hoc va dong Iyc hoc ciia qua trinh cat dat if dang biia 3.3.1 Quan he ddng hgc cita qua trinh cdt ddi Can cir vao nguyen ly cat da dugc trinh bay a tren ta thiet lap sa dgng hgc cua he th6ng cat dat va dugc the hien tren hinh Trong qua trinh cat, dao thuc hien hai chuyin dgng: - Chuyen dgng tuong doi quay quanh dilm [Jx(^-(y,) = m„(5_,) + m„(5„) Trong do: M - Khoi lugng cua dao, kg V(i - Van toe cua dao tai diem O, m/s Vot - Van t6c ciia dao tai kh6i tam C, m/s SA - Xung luc va cham tai dilm A, kg.m/s S(,i - Xung luc va cham tai dilm | , kg.m/s J - Mo men qua tinh, kgm^ u - Van toe goc ciia dao truoc va cham, radian/s Mo - Van toe goc ciia dao sau va cham radian/s m()(SA) - Mo men ciia xung luc (SA) dii voi diem O, kgm^/s mo(Soi) - Mo men cua xung luc (SA) ddi vai diem [ , kgm"/s vai: V^=i)0^.e = 00^.(p-ii/\ f^,, = C X > = (00,+0,C).5? o>,.=^ •,co = e = ^-iy M[()(\.(p-0,C.(p-(00,+(\C)^'] ch6tO| vaigocG, ( < ' < ^ ) = S,^•i^, J {(/>) = m„ (S,) = ( 0 , + 0,C)S, - Chuyen dgng theo ciing vai chot | quay quanh O vai goc cp^=cot do: lu la van toe goc ciia dta, ip^^ dau A: (y, = ^ = O.C^liJ., Trong do: R,,- Khoang each tir diem O den diem | / - Chieu dai dao cat Suy tir dieu kien: iS,={H,-l)M.o, l.S.=2^.W.ffl ^ (7) 3.4 Qua trinh cat dat va di chuyen dat J 4.1 Luc cdt ddt Thay cac dai lugng vao cong thiic (1) va chilu len phuang vuong goc voi OA ta co: (2) Vai xung lugng ciia dao va dap vao dat dugc xac dinh nhu bieu thiic (3) thi dat bj pha va ket cau tai dgng Co the xem nen dat la tam dan hoi dat tren nen co djnh chiu va cham voi tai SA va van toe va cham la van toe dau dao A truac thoi diem va cham: VA = (R(i+/ )o> Luc cat dat va cham dugc xac djnh theo cong thirc tinh tai trgng dgng va cham ngang: P„ =PrK Giai lie phuang trinh (2) ta dugc: • , = - (6) -(Mffl) -;-.J,,.co (3) (8) Trong do: Pma\ - Lyc cat dat lan nhat, N P, - Luc cat va cham tao ra, N Kd - He so va cham Luc cat va cham: Xet anh huong giua cau tao cua dao voi xung luc va cham TAP CHl CONG NGHIEP NONG THON - SO 12 - 2014 k.,=Jg-^t KHOA HOC - CONG NGHE 6) lam cho mui dao A luon ty sat vao day ho Ta CO the tinh dugc dp lire NA theo phuang trinh can bang momen chuyen dgng tuong doi: Voi; V - van toe vacham: v = v, =(«„ + /) (U ti: - Thai gian va cham A/ - bien dang tai diem va cham, co the tinh theo ly thuyet liin ciia nen dat Do liin At co die dugc xac dinh bang thi nghiem vai cac loai dat: Tir do, luc cat dat va cham la: P = ^ ^ ^ ;N (9) ', 4^ Thay xung luc SA tinh theo cong thuc (3) vao cong thuc (9) ta co luc cat dat qua trinh va cham la: ;N (i X / /V_, = • ^ [ / ^ ^ , s i n ( + ^ ) + P s i n ( ) ] (12) Khi ^ = —; j ^ = a \'i tri thap nhat ap lire Ion nhat ciia dao len day ho dugc tinh theo cong thirc sau: O.Cr (13) A'., ^[^.-"l (10) -JgAt Trong do: ti- thoi gian va cham, tlioi gian va cham du(?c tinh theo cong thiic sau: h ',=- (11) Trong d6: h- chieu sau Iu5i cat di xuong dat;( m) Tir cong thirc (10) ta co nhan xet sau: - Thcri gian va cham rat ngan nen luc cat Pmax la rat lon, cimg vai he so dpng Kj, tir Iam cho lu&i cdt di sau xuong dat, nen nang suat cdt rat cao, tir day cho thay co the giam dugc cong suat dgng ca ma nang suat cat van lan - Qua trinh cat dang bua la rat phiic tap, co nhieu thong so dong thai tham gia vao qua trinh cat Cong thirc tong quat tinh lire cdt theo phuang phap cat dang biia (10) da bao ham cac he so anh huang ciia cac yeu to, cac he so khac nen anh huang cung khac 3.4.2 Chuyen dpng cua duo cdt long hd Sau thoi diem va dap, chot O] van chuyin dgng quay quanh O, no keo dao chuyin dgng theo lam cho dao co chuyen dgng song phang: quay tucmg d6i quanh Oi va chuyin dgng theo ciing ch6t O] Trong chu\en dgng tuang d6i quanh Oi, co luc quan tinh ciia kbli tam C nen CO xu hucmg quay thuan kim d6ng h6 (hinh 26 Hinh Sa tinh dp luc cua dao cat long lio IV KET LUAN Tir cau tao va nguyen ly lam viec ciia he thong cat dat dang biia ciia may phun dat cat chira chay rimg, da lap dugc sa tinh toan dong lire hgc ciia he thong, tir da thiet lap dugc cong thirc tinh toan xung lire va cham ciia dao cat (3) va lire cat dat qua trinh va cham (10) Nhiing ket qua nghien ciru da dugc ap dung tinh toan thilt ke he thong cat dat cua may phun dat cat chiia chay rimg TAI LiEU THAM KHAO Biii Anh Djnh (2004), Ca hoc dk, Nxb Xay dyng Ha Noi Chu Tao Doan (2001), Co hpc ly ihuy^l, Nxb Giao thong Van tai Ha Noi D6 Sanh Nguyen Van Vugng (2000), Ca hgc irng dung Nxb Khoa hoc ky thuat, Ha Noi Duong Van Tai (2010), Bao cao kit qua d l tai diem cap nha nuoc, " Nghien ciru cong ngh^ vh thiet ke che tao cac thiet bj chuyen dung ch&a ch^y rimg" ma s6 KC07.13/06-10, Cue thong lin khoa fipc & cong nghe quoc gia Ha Noi Ngay nhan bai: 15/02/2014 Ngay phan bi^n: 28/02/2014 Ngiroi phan bien: TS Doan Xuan Thin, Hpi co khf nong nghiep Viet Nam TAP CHi CONG NGHIEP NONG THON - SO 12 - 2014 ... theo quan tinh va rai xuong Nhu vay dat dugc cat va tung len rat thuan lgi cho qua trinli hut de phun dat vao dam chay de dap liia TCr qua trinh phan tich nguyen ly cdt ddt dang biia a tren co... long lio IV KET LUAN Tir cau tao va nguyen ly lam viec ciia he thong cat dat dang biia ciia may phun dat cat chira chay rimg, da lap dugc sa tinh toan dong lire hgc ciia he thong, tir da thiet... cham (10) Nhiing ket qua nghien ciru da dugc ap dung tinh toan thilt ke he thong cat dat cua may phun dat cat chiia chay rimg TAI LiEU THAM KHAO Biii Anh Djnh (2004), Ca hoc dk, Nxb Xay dyng Ha