Tính toán và lựa chọn một số thông số chính làm cơ sở cho thiết kế chế tạo mô hình máy gặt lúa, liên hợp với máy kéo nhỏ ở đồng bằng bắc bộ

Tap chi Khoa hoc va Phat tri6n 2010: Tap 8, sd 6: 1011 - 1016 TRlTCiNG DAI HOC NONG NGHIEP HA NQl TINH TOAN VA LUA CHON MOT SO THONG SO CHINH LAM CO SO CHO THIET KE CHE TAO MO HINH MAY GAT LUA, LIEN HOP VOH MAY KEO NHO DONG B A N G BAC BO Calculate and Select a Number of Key Parameters as the Basis for Design and Manufacture Model Machine Harvest, Combined with a Small Tractor in the Northern Delta Le Van Bich, D6 Dinh Thi Khoa Ca dien, Tru&ng Dgi hgc Nong nghiep Hd Ngi Dja chi email tac gia lien lac: levanbichson(^yahoo.com TOMTAT Ca giai hoa gat lua da t r v nen c i p t h i l t doi vm d6ng bing B i c bo Cac m i u may gat cua niro'c ngoai va mot vai m i u a mien Nam du'O'c c h l tao du'O'i dang chuyen dung nen gia cao va chu'a that phu ho'P vai dac tinh (J6ng ruong va tap quan canh tac cua nong dan m i l n B i c Vi vay viec nghien ciru, thilt k l , c h l tao mpt mau may gat du'O'i dang bo phan gat, lien hap vai may keo nho, loai may dang du'p'c SU' dung rpng rai a m i l n B i c , se gop p h i n lam giam gia may va phii hp'p \if'\ dac tinh d i n g rupng miln Bic Bai bao trinh bay k i t qua tinh toan va lira chpn mpt s6 thong so chinh lam c a sa cho thilt k l c h l tao mo hinh may gat lija, lien hpp vai may keo nho a dong bang Bac bp TO khoa: Bp phan gat, lien hp'p \icf\ may keo nho, may gat SUMMARY Mechanized harvest has become imperative for the northern delta The pattern of foreign harvesters and a few samples were built in the south as a special so the price is high and not very consistent with the field characteristics and farming practices of farmers north So the research, design, manufacturing a sample harvester as harvester parts, associated with small tractors, machines are being used widely in the north, will contribute to reducing the cost of the machine and line with the North field characteristics In this paper, we calculate and select a number of key parameters as the basis for model design and manufacture machine harvest, combined with a small tractor in the northern delta Key words: Associated with small tractors, harvesters, harvester parts D A T V A N -DP i jji\\ v/\iN UEJ Cd gidi hda gat Ifla da trd nen cap thiet dd'i vdi dong bang Bae bd Cac mau may gat eiia nflde ngoai va mot vai m l u d mien Nam dfl(3e ehe tao dfldi dang chuyen dflng nen gia edn eao va chfla that phfl hdp vdi dac tinh dong ruong va tap quan canh tae eua ndng dan mien Bae Khac vdi dong bang Nam bd, eae thiia ruong d dong bang Bae bd thfldng nhd hep va phan bd' manh mun Trong mdt lang, xa, cac thiia ruong thfldng khdng cd cflng mot binh do, din tdi thdi ky thu hoach, nen ruong ed lun, ngap nflde khac nhau, gay rat nhieu khd khan cho viee ed gidi hda khau thu hoach May gat chuyen dflng chi dfl(3c sii dung thdi ky thu hoach O mien BSe, mot nam chi cd hai vu lua vdi tong thdi gian thu hoach nam khoang tfl 30 de'n 45 Dieu dd lam eho thdi gian khau hao may bi keo dai Ngfldi ndng dan mien Bae, tiem IvJe kinh te edn ban che, ludn mud'n sfl dung phan ddng lflc va phan di chuyen ehung cho eae cdng viec khac nam Vi vay viec nghien cflu, thiet ke, che tao mot mku may ion Tinh toan va lya chpn mpt so thong so chinh lam co' so cho thiet ke che tao mo hinh may gat lua, gat dfldi dang bd phan gat, lien hgg vdi may keo nhd, loai may dang dU6c sii dung rong rai ci mien Bae, se gdp phan lam giam gia may va phu hgp vdi dac tinh dong rudng mien Bae Tinh nang lam viee eua may keo nhd va dac tinh lam viee eiia bo phan gat la ra't khae Viee tinh toan, thiet ke, ehe tao may lien hdp phai dam bao cd dfl(3c tinh nang td't nha't cho ea hai bd phan tren Bai bao trinh bay ke't qua tinh toan va Ifla chon mot sd' thdng so' ehinh lam ed sd eho thiet ke che tao may gat lua, lien hgg vdi may keo nhd d dong bang Bac bo DOI T U O N G VA PHUONG PHAP NGHIEN CtJtJ Dd'i tfl(3ng nghien cflu la cae loai may gat xep dai phfl h(3p vdi lua va tinh trang dong rudng d dong bang Bae bo; Cae may keo nhd vdi eae dong lflc D6, D8, DlO dang dfl(3e sv( dung phd bie'n d dong bang Bac bd De tinh toan va Ifla chqn mot sd' thdng sd' lam cd sd eho thiet ke ehe tao md hinh may gat lua, lien hcg vdi may keo nhd, thfle trang dong rudng, gid'ng lua va tap quan eanh tae tai dong bang Bae bd da dfl(3e khao sat Ben canh dd, nhdm nghien cflu edn tham khao cac mau may da ed nflde va nflde ngoai, phan tich flu nhfl(3c diem cua may, Ifla chon ke't ca'u phfl hdp nha't; thu thap xii ly thdng tin qua sach bao, tap chi, Internet va tham khao y kien chuyen gia Dfla tren ly thuyet tinh toan thiet ke may gat va gat dap lien h(3p (Melnhieop, 1957), may gat dfliJe thiet ke theo giai phap phan gat lien h — V ^ c o s cc 100 '" (*) X la quang dfldng dich chuyen eua dao tfl vi tri ban dau (vi tri diem che't trai) Dao thfle hien viee cat cay khoang tfl Xb de'n Xk Tfl cac thdng so' ca'u true eiia dao, xae dinh dflde: Xb = 0,0141 m; Xk = 0,0423 m (Melnhieop, 1957) Cdng viee tie'p theo la Ifla chqn, tinh toan td'e quay eiia eO eau bien tay quay de thda man dieu kien (*) eho moi sd'truyen (Bang 2) Tfl ke't qua tinh toan tren ta tha'y: - Van td'e doc theo canh sac d thdi diem bat dau cat (Vtb) ludn dam bao dieu kien (*) - Van td'e doe theo eanh sac d thdi diem ke't thuc cat (Vtk) ehi thda man dieu kien (*) vdi cac gia tri co nha't dinh va phu thuoc vao so'truyen: so'truyen II, co>80 rad/s; sd'truyen III, co>118 rad/s; sd'truyen IV, co>186 rad/s 1013 Tinh toan va lya chpn mpt so thong so chinh lam co' so cho thiet ke che tao mo hinh may gat lua iZ- 051 j \ R3 J2 50 Hinh Cac thong so cua bo phan cat v., \ f V' Hinh SO xac dinh van toe doc theo canh sac cua dao cat Bang Ket qua tinh toan van toe d cac so truyen Sdll Q Vmcosa Vdbsina Vdksina Vtb Vtk S6III U) Vmcosa Vdbsina Vdksina Vtb Vtk So IV CJ Vmcosa Vdbsina Vdksina Vtb Vtk 1014 70 0,644 0,715 0,573 0,071 -0,071 72 0,644 0,735 0,590 0,091 -0,054 74 0,644 0,755 0,606 0,112 -0,038 76 0,644 0,776 0,622 0,132 -0,021 78 0,644 0,796 0,639 0,153 -0,005 80 0,644 0,817 0,655 0,173 0,011 82 0,644 0,837 0,672 0,193 0,028 84 0,644 0,858 0,688 0,214 0,044 86 0,644 0,878 0,704 0,234 0,060 110 0,954 1,123 0,901 0,169 -0,054 112 0,954 1,143 0,917 0,189 -0,037 114 0,954 1,164 0,934 0,209 -0,021 116 0,954 1,184 0,950 0,230 -0,004 118 0,954 1,205 0,966 0,250 0,012 120 0,954 1,225 0,983 0,271 0,028 122 0,954 1,246 0,999 0,291 0,045 124 0,954 1,266 1,016 0,312 0,061 126 0,954 1,286 1,032 0,332 0,077 176 1,515 1,797 1,441 0,282 -0,074 178 1,515 1,817 1,458 0,302 -0,057 180 1,515 1,838 1,474 0,323 -0,041 182 1,515 1,858 1,490 0,343 -0,024 184 1,515 1,879 1,507 0,364 -0,008 186 1,515 1,899 1,523 0,384 0,008 188 1,515 1,919 1,540 0,404 0,025 190 1,515 1,940 1,556 0,425 0,041 192 1,515 1,960 1,572 0,445 0,057 Le Van Bich, Do Dinh Thi 3.3 Tinh toan xac dinh van toe bat dau va ket thiic cat Chon van td'e lam viee cua bd phan cat la mot viee ra't quan Vdi bd phan cat loai nay, van td'e cat eang eao thi kha nang eat cang td't, nhflng gay lflc quan tinh ldn lam tang sfl rung ddng may, gay hao phi nang Iflcfng khdng can thiet, lam giam tud'i tho eiia dao eat Van td'e td't nha't dfl(3e Ifla chon la van td'e ehi vfla du de eat eay Van td'e dflcic goi la van td'e eat ky thuat (Vkt), gia tri eua nd phu thude vao dd'i tfl(3ng dU6c eat Cae thi nghiem da chi ring, dd'i vdi eay lua nflde Vkt =1,2 m/s, nghia la dao ehi eat dflde Ilia ne'u van td'e vflng eat (Hinh 3) cua no ldn hdn 1,2 m/s Dieu kien tren dfl(3c viet nhfl sau: Vb > Vkt; Vk >Vkt Vb- Van td'e dao luc bat dau eat; Vk- Van td'e dao lue ke't thfle cat Nhfl vay, de qua trinh cat cay dfl(3e bao, van.td'e cua dao cat khdng nhflng thda man dieu kien (*) ma cdn phai man ca dieu kien (**) (**) dam phai thda Vung van td'e cat thda man dieu kien (*) da dflde xae dinh d phan tren, ta chi can tinh toan xae dinh cac gia tri Vb va Vk Kiem tra theo dieu kien (**), ne'u khdng dat, phai tinh toan, Ifla chqn lai Cae gia tri Vb va Vk ed the dfl(3e xae dinh bang phfldng phap thi hoae bang phfldng phap ke't hdp thi va tinh toan Tfl thi, va xae dinh dflde yb va yk; yb = 22,5 (mm); yk = 18,1 (mm) Tie'n hanh xae dinh Vb va Vk theo cac bieu thfle: Vb = yb.co; Vk = yk.co Tinh toan kiem tra cae gia tri eho tflng so'truyen theo dieu kien (**) So'truyen II; (a> = 80 rad/s) Vb = yb CO = 22,5 10-=* 80 = 1,80 m/s Vk = yk CO = 18,1 10-' 80 = 1,45 m/s Sd truyen III; ( = 118 rad/s) Vb = yb CO = 22,5 IO"' 118 = 2,66 m/s Vk = yk CO = 18,1 10-' 118 = 2,14 m/s So truyen TV; (co =186 rad/s) Vb = yb CO = 22,5 IO'' 118 = 3,37 m/s Vk = yk CO = 18,1 10-' 118 = 4,19 m/s Nhfl vay, ea ba so' truyen da Ifla ebon deu thda man dieu kien (**) Hinh Do thi xac dinh van toe Iam viec cua dao I^tfi Tinh toan va lya chpn mpt so thong so chinh lam co so cho thiet ke che tao mo hinh-may gat lua, KET LUAN Ke't qua tinh toan, liJa chqn, kiem tra, da xac dinh dfl(3c dac tinh td'e eiia dao eat phu h(3p vdi ba so' truyen tfldng flng eiia may keo nhd Bd phan eat dfl(3c se dfl(3e thiet ke cd be rdng lam viee la 1,2 m Khi lam viec, chieu dai thflc te la'y la m Do vay nang sua't thuan ciia may lien hdp tfldng flng se dat: 2601 m % tfldng dfldng vdi 7,2 sao/h di chuyen vdi sd' truyen II 3858 m^lh tfldng dfldng vdi 9,1 sao/h di chuyen vdi sd'truyen III 6120 m^lh tfldng dfldng vdi 14,4 sao/h di chuyen vdi so' truyen IV Tfl cac thdng sd' tren, cd the xac dinh dflde cae ty sd' truyen tfl true trich cdng sua't tdi cd ca'u truyen dong cua dao cat va eae bd phan khae Tat ea cae thdng sd' xac dinh dfl(3c se la ed sd cho viee thiet ke, che tao may gat lien h(3p vdi may keo nho TAI LIEU THAM KHAO Bo Ndng nghiep va PTNT (2002a) Tuyen tap tieu chuan ed dien ndng nghiep Viet Nam, Tap , Ha Ndi Bd Ndng nghiep va PTNT (2002b) Tuyen tap tieu chuan cd dien ndng nghiep Viet Nam, Tap II , Ha Ndi Melnhieop C B (1957) Bai tap thiet ke may ndng nghiep, NXB Masedva Cdng ty Meiwa, Kubota - Nhat Ban (1998) So' tay ngfldi sit dung may gat lua Nguyin Bang, Doan Van Dien (1990) Ly thuyet tinh toan may ndng nghiep, NXB Giao due, Ha Noi Pham Xuan Vfl(3ng (1999) May thu hoach ndng nghiep, NXB Giao due, Ha Noi • ' ) 1016 ... tao may lien hdp phai dam bao cd dfl(3c tinh nang td''t nha''t cho ea hai bd phan tren Bai bao trinh bay ke''t qua tinh toan va Ifla chon mot sd'' thdng so'' ehinh lam ed sd eho thiet ke che tao may... va li^a c h o n cac thong so ban dau 3.1.1 Cho may keo nho May gat dflde thiet ke het vu gat, phan gat dfl(3c thao ra, tra lai chflc nang binh thfldng cho may keo nhd Tinh nangdi chuyen cua loai... edn tham khao cac mau may da ed nflde va nflde ngoai, phan tich flu nhfl(3c diem cua may, Ifla chon ke''t ca''u phfl hdp nha''t; thu thap xii ly thdng tin qua sach bao, tap chi, Internet va tham