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KHOA H O C - C O N G NGHE KET QUA THi NGHIEM XAC DINH MOT SO THONG SO PHU THUOC VAO DAC TiNH c a LY CUA ROM Tl/Ol TRONG QUA TRINH CAT ROM Nguyen Vdn Tam ' Le Minh Lir' NguyenXudn Thiet" TOM TAT Hien ram sau thu hogch lua da vd dang dugc nghien ciru vd xir ly theo nhieu hirdng ldm cho nguon ram, rg cdng cd gid trj han Trong hdu het cdc phirang dn xu ly viec xdc dtnh cdc dgc tinh ca ly cua ram la cdn thiet Trong phdn nghien ciru ndy nhdm tdc gid giai thieu mpt so thdng \d phu thupc vda dgc linh ca ly cua ram tucri nhu: dnh hudng cua gdc cat trugt den dp luc cdt thdi rieng vd cong cdt rieng anh liicdng ciia khe giira mat ben cita dao vai Idm ke den dp lire ep khdi ram dd dm/c cat vdo ben ciia dao; dnh hut'mg cua dp hrc ep den dp bien dgng ciia khdi ram tirai qud trinh ep: he so ma sdt cua ram tuai vdi thep vd khdi luang rieng cua ram tirai Viec xdc djnh quan he va dgc diem tren lam ca sir de nghien ciru, tinh todn bp phgn cdt ram dong thdi la ket qud ujig dung cho cdc cdng trinh nghien ciru kliac lien quan den rain tirai Tir khoa: Ram rg bp phcin cat, mdy cdt ram EXPERIMENTAL RESULTS DETERMINING SOME OF PARAMETERS DEPENDENT OF THE PHYSICAL-MECHANICAL PROPERTYOF FRESH STRAW IN THE PROCESS CUT STRAW Nguyen Van Tam ', Le Minh Lu \ Nguyen Xuan Thiet"' SUMMARY The currently straw after harvesting has been much research and treatment direction, make resources straw increasingly more valuable In most of the straw treatment plan defining the physical-mechanical property of straw is needed In this study, Uie authors introduce a number of parameters depends on the physicalmechanical property of fresh straw as: effects of shear cutting angle to specific cutting pressure and specific cutting public; effects of slot between the side face of the knife with chocking plate to press pressure of straw blocks were cut on the side face of the knife; effects of press pressure to deformation of fresh straw in the compression process; coefficient of friction of fresh straw with steel and specific weight of fresh straw With the relationships and characteristics of fresh straw as the basis for research, calculating the straw cutting parts, concurrently applied to the results of other studies have a connection with fresh straw Keywords: Straw, cutters, straw cutters I DAT VAN DE Doi vai viec thiet ke che tao cac bg phan hoac may cat thai ram, cho den da co nhieu mau may sii dung cac nguyen ly cat thai khac Song, vai mgi nguyen ly cat thai de xac dinh dugc nSng lugng ck thai tinh toan 1^ thuydt, mgt thong so quan trgng can dugc xac djnh la ap luc cat thai rieng qc,(N/cm) Ap lire cat thai rieng q^ la lire can thiet de cat diit vat thai theo phuang vuong goc vcri luai dao tren mgt dan vi chieu dai lam viec ciia ludi dao Vai nguyen ly cat thai dao co dinh, canh gat (xkn ke) chuyen dgng (hinh 1) dS xac dinh ap luc cat thai rieng qd can xac dinh lire cat thai cin thiet Pa(N) va dai doan luai dao cat AS(cm) Khi ap luc cat thai rieng dugc xac dinh theo cong thurc (Tn'tn Minh Vuang vd Nguyin Thj Minh Thuan, 1999): p^ ^" ~ A.9.(l-i-/.tanr).cosr Trony do- ^'^ I ThS Tmimg Cao ding ngha co gioi Ninh Binh P^i- Luc cat thai can thiet theo phuang van ^ TS Trudng D^i hpc Nong nghidp Ha Npi ^^^ ^jg^ ^ ^ j ' TS Tni6ng Dai hgc Nong nghidp Ha Npi TAP CHi CONG NGHlfP NONG THON - SO 12 - 2014 27 ^^^9/j sr KHOA HOC - CONG N G H E f - he so ma sat cua rom tuai \ a thep; T - goc cat trugt Tir (I) ta thay ap lire cat thai rieng qo phu thugc vao goc cat trugt T va he so ma sat f, \ay can nghien ciiu anh huang cua goc cat trugt T den ap lire cat thai rieng qd De xac dinh luc T2 hay tinh cong cat rieng ta phai biet dien tich mat cat ngang ciia kh6i ram sau dugc nen den trang thai cat, vai ly ta can nghien ciiu quan he giiia ap lire nen va bien dang tuong doi ciia khoi rom nen: De thuan lgi cho viec phan tich cac phan lire tac tac dung len dao qua trinh cat, xet sa qua trinh cat truong hgp goc cat trugt T = O" (hinh 1) Khi cat thai cac vat dan hoi qua trinh cat co hai giai doan; dau tien la luoi dao nen ep vat thai mgt doan, roi den cat dut vat thai Trong qua trinh luai dao di vao vat thai phai khac phuc cae lire ma sat luc dan hoi N2 ctia phan khoi ram da dugc cat tac dgng vao mat ben cua dao va ly:c N| vat thai dich chuyen bj nen ep tac dgng vao mat vat cua canh sac luoi dao Neu ggi P, la lire can cat thai thi luc cat thai can thiet Pd la: P^, =/^+2.r,+2,7;.cos/-H2A'iSinv;(N) (2) Neu ggi ap luc nen ram la qn (N/cm^), ggi ho la chieu cao ban dau cua khoi rom a trang thai tu nhien: h,, la chieu dai doan duang nen ty so nen dugc dinh ngliTa theo cong thiic: h (3) e = -^ k Neu ggi Sn la dien tich mat cat ngang phan khoi ram dugc nen, de xac dinh dugc chieu cao khoi ram ban dau ho ta phai biet dugc khoi lugng rieng ciia ram tuoi pr Vai phan tich can xac djnli dugc quan he giiia ap lire nen q,, voi ty s6 nen s hoac vai khoi lugng rieng ciia rom tuai De xac djnh moi quan he gifla cac y^u t6 da dugc phan tich cac ngi dung tren, can thiet ke thi nghiem va phan tieh ket qua nghien Trong do: y la goc mai dao doi voi cat rom ciixi de xac dinh cac moi quan he chgn y= 15" IL VAT LIEU VA PHUONG PHAP NGHIEN CUtJ 2.1 Vat lieu Vat lieu thi nghiem la rom tuai lay tai thoi diem sau gat mgt nga> tir gidng lua BCI5 Cac ket qua nghien ciiu ban dau ve dac tinh ciia rom tuoi dugc thuc hien tai Khoa Ca dien Truong Dai hgc Nong nghiep Ha Ngi De CO mau ram thi nghiem nhu inoi loai thi nghiem mau rom deu dugc chon theo don vi khoi lugng tren chi^u dai mau rom Doi voi thi nghiem xac dinh anh huang ciia goc cat trugt T den ap luc cat thai rieng qd, moi mau Hinh I Sa qud trinh cdt thai bang lirai dao cd dinh ram co khoi lugng bang lOg voi chieu dai mau Tu (2) ta thay luc ma sat T; kh6i roiu da rom 20cm Doi vai mau ram thi nghiem xac dugc cat vao mat ben ciia dao co anh huang djnh quan he giira ty so nen e va ap lire nen qn, den luc ck thai c4n thi^t Pd- Song d6i vai moi mau ram co khoi lirgng 50g vai chieu dai nguyen 1\ iia\, luc ma sat T: phu thugc vao khe mau ram 20cm Mau rom thi nghiem dugc xac S (5 la khe ho gitra mat ben cua dao va tSm djnh bang can dien ttr METTLER TOLEDO tai ke) Vai phan tich can nghien ciiu anh phong Cong nghe tk bao thuc vat - Khoa Cong hucmg cua khe din ap lire kh6i ram da nghe sinh hgc - Truang DHNN Ha Ngi dugc cat tac dgng vao mat ben ciia dao 28 TAP CHi CONG NGHIEP NONG THON - SO 12 - 2014 KHOA HOC - CONG NGHE 1kg vao til sdy va sdj' nhiet 70 C sau moi khoang thai gian bo can den nao mau rom co khdi lugng khong d6i so vai lan can truac thi dimg lai idy hieu s6 khdi lugng ram trudc va sau say ta dugc lugng nude cd rom tuai Tinh phan tram lugng nude cd mau ram tuai ban dau chinh la am ciJa mau ram Qua trinh do am dugc thuc hien lap lai lan va ket qua cho tren bang I Thi^l bi ma sat GUNT de ma sat giita rom va thep tren be mat phang ciia thiet bj dat mgt tdm thep vdi be mat thep phang, bdng be mat thep d dang tu nhien (khdng danh bdng be mat) Mau ram thi nghiem dugc lay ngau nhien cac cgng ram tir khoi ram va dan len mgt tam bia cimg de tao mat phang ciia mau ram Qua trinh thi nghiem: dat mau ram len tam thep va thay ddi gdc nghieng cua tam thep cho den mau rcrm bat dau trugt tren mat phang tam thep, nhin vao vi tri goc ciia thiet bj GUNT tai vj tri gdc nghieng ling voi mau rcrm cd hien tugng trugt ta dugc gia trj gdc trugt cua ram va thep, Cotan ciia goc trugt la he sd ma sat ciia ram tuai va thep Sd thi nghiem dugc thuc hien lap lai lan, ket qua dugc trinli bay tren bang Dung cu ap lire nen va ty so nen cd khudn ep dang hinh hop chfl nhat vdi chieu dai day khuon bang 10cm, chieu rdng day khuon bang 1,4cm va chieu cao khudn bang 4cm, khuon ep dang khudn hd ehi cd mat day va hai khudn theo chieu dai khudn Pittong ep cd mat ep chieu dai 8cm, chieu rgng 1,35cm Cac h) Dv"g c(( (to /(/I mau ram ep cd ciing khdi lugng tren cimg dan Hinh Cdc dung cy vd thiit bi vi chieu dai mau rom la 50g/20cm Mau ram Can dien tii METTLER TOLEDO tai phong dugc nap day vao khuon ep ban dau bang tay Cong nghe te bao thue vat - Khoa Cong nghe cho mau ram day khudn ep Dung cu ap sinh hgc - Truang DHNN Ha Npi Can co dai luc nen dugc lap tren may keo nen van nang tir lOmg -i- 220g Can dung de xac dinh cac AUTOGRAPH-AGS-20KNG mau ram ed cimg khoi lugng tren ciing mgt Dung cu luc cat: Dung cu gdm cd mdt chi^u dai khong doi eiia mau ram dao cat dat d vi tri giua khe hd cita hai tam ke Tu siy FN 500P eo the tieh bu6ng sdy 120 hai ben Dao eat dugc lam tir thep CT45, bk day lit, dai nhiet dg tir SO'^C din 250°C, eong sudt dao 5mm, cao ben dao 50mm, canh sSc 1600W Tu sdy dimg de do am cua ram tuai ludi dao dugc tao bang each mai hai ben vdi bang each: cho mau ram tuai vai khoi lugng TAP CHi CONG NGHIEP NONG THON - SO 12 2014 29 2.2 Thiet bi va dung cu De va ghi nhan ket qua cac thong so thi nghiem tren, cac thiet bj va dung cu can thiet duac trinh ba\ tron^ hinh KHOA HOC - CONG NGHE gdc mai dao 15", dao cat dugc tap vao gia lien k^t vcri may keo nen va dao cd the thay ddi dugc cac gdc nghieng theo phuong ngang so vdi gia lien ket Tam ke cat dugc dinh hinh dang khudn vdi chieu cao khudn 40mm, be rgng day khudn Mmm nham muc dich xac dinh chieu dai lam viec ciia canh sac luoi dao AS, tam ke cat dugc che tao cho cd the quay theo gdc nghieng ciia dao de thi nghiem vdi cac dang gdc trugt khac nhau, ddng thdi bd phan cat cd the thay ddi dugc khe hd gifla hai tam ke nham thay ddi khe hd giua dao va tam ke Mau rom thi nghiem dugc dat vao hai tam ke va dugc ep chat hai dau tren hai tam ke nhd vit ep tren tam ke Dung cu thi nghiem lap tren may keo nen van nang AUTOGRAPH-AGS-20KNG trinh bay tren hinh 2g May keo nen van nang AUTOGRAPH-AGS20KNG cd dai tir -^ 20 kN dugc trang bj bg CPU xir ly va man hinh Control Display de dieu chinh che dg van hanh may va hien thj k^t qua dang sd Tren man hinh cho bi^t luc cat (hoac nen) va doan dudng di cua dao cdt (hoac pittong) qua trinh thi nghiem Tir k^t qua ghi nhan ta cd dugc thj quan he giua luc cat va chuyen vi cita dao qua trinh cdt III KET QUA VA THAO LUAN 3.L Ket qua gia tri cac thong so dac tinh ciia rem tu'oi Ket qua do am, khdi lugng rieng p„ he sd ma sat f gifla ram tuoi va thep voi sd ldn thi nghiem lap lai lan cho cac k^t qua dugc trinh bay bang Theo ket qua nghien ciiu (Nguyen Dire Long, 2004) ddi vdi rom khd a dm 15% co khdi lugng rieng pr = 48kg/m"' va he sd ma sat giiia ram khd va thep f = 0,61 Tir ket qua nghien ciru ve ram tuai am 70,4% cd kh6i lugng rieng pr = I k g W va dac biet cd he s6 ma sat f ^ 0,55 nhd hon so vdi he s6 ma sat giiia rom khd va thep 3.2 Ket qua thi nghiem quan he giira t) so nen va ap luc nen doi vol rom tuoi K^t qua thi nghiem quan he gifla ap lire nen q„ (N/cm") va ty so nen tuang ddi e dugc trinh bay tren dd thj hinh Tir sd lieu thi nghiem qua phan tich hoi quy ta cd ham hdi quy md ta quan he gifla ty sd nen e dugc tinh theo ap lire nen q„ vdi he sd tuong quan R" ^ 0,9693 nhu sau: E = 0,l644.ln(q„)~ 0,1335 (4) ai|oumh^i Hinh Do till thire nghiem i/iiun lie £-q„ Ung dung cong thuc (4) de xac dinh chieu cao kh6i rom a trang thai bit d&i cffl Nhu da trinh bay o tren, qua trinh cat co hai giai doan: giai doan nen va giai doan c5t Gia sir ta xac djnh duoc ap lire nen den trang thai cat la q„, tir (4) ta tinh ditgc ty s6 nen e, theo (3) chieu dai Bdng I Kit qud cdc thdng sd dgc tinh cua ram timi doan duong nen hn chinh la giam chiSu cao cua khoi rom nen, chiSu cao ciia khoi Thong So lan Trung rom trang tliai bat diu cat la: h^ = h„ - h„ Bijt s6 Lan Lan Lan Lan Lan binh dugc he ta xac dinh dugc chi^u dai doan dao lam Do am viec AS 67 73 75 72 65 70,4 P (ks/m') He so ma sdt f 30 105 95 120 115 90 105 0,53 0,49 0.58 0,55 0,59 0,55 3.3 Kef qua thi nghiem anh hu'olig ciia goc truol den cac thong so qua trinh cSt Nhu phan tich tren qua trinh cat co hai giai doan: giai doan nen va giai doan cjt Cac phan luc anh huong giai doan cat TAP CHi CONG NGHIEP NONG THON - SO 12 • 2014 KHOA HOC - CONG NGHE \\ tri cua dao, qua dd ta thu dugc bang gia trj lire Pc cho timg trudrng hgp gdc trugt, tir ket qua gia tri lire P^ va djeh chuyen eua dao vao khdi rom qua trinh eat ta xay dung dugc thi cho cac muc gdc eat trugt T = ; 15 ; 30**: 45"; 60" va 75" Cae giai doan qua trinh eat va eae phan lire anh hudng qua trinh cat dugc the hien qua ket qua thi nghiem dugc trinh bay bang dd thi thue nghiem (do thj cdng) hinh gdm cd cac phan: Luc cat tac dung true tiep len canh sac luai dao P,, luc can nen len mat vat cua canh sac luai dao Ni va lire ma sat T cua phan khdi ram da dugc cat len mat ben ciia dao (thanh phan lire T dugc the hien dao da cat het khdi ram va tiep tuc di xudng, gia trj ghi nhan dugc tir man hinh cua may keo nen) Tir ket qua thi nghiem, nho thiet bj luc cat va dich chuyen cua dao qua trinh cat bang may keo nen van nang ta cd dugc gia tri luc cat theo phuang van tde dao Pc tai timg " ^ l " ' Kal quatHi •ghiem van2 Lan TB 132,55 113,63 132,55 126,24 8(mm) 113,64 94,55 113,64 75,64 113,64 94,55 113,64 88,24 75,64 56,91 56,91 63,16 56,91 56,91 56,91 56,91 Tir ket qua bang ta cd thj va ham hdi quy md ta quan he giiia ap lire cua khdi ram da duge cit len hai ben eua dao d cac muc khe trinh bay tren hinh va cdng thirc (9) Phuang trinh hdi quy vai < mm: -1,8915.(5 + , ; ( - ^ ) (9) Phuong trinh hdi quy (9) md ta quan he gija qt/N/cm^) va (mm) ed he sd tuong quan R^ = 0,9695 IS-giSn-rlAflig S phdn cdi rom lien hap vai mdy dap liia Tap chi khoa hpc v^ phat trien, Tap L so 5: 735 - 744 [5] Tran Minh Vuong va Nguyin Thj Minh Thuan (1999), Mdy phuc vu chan nuoi, NXB Giao due Ngay n h a n bai; 18/02/2014 Ngay p h a n bi?ii; 10/3/2014 Nguoi p h a n bien: GS.TSKH Pham Van Lang, Hpi CO nong nghiep Viet Nam - Vdi cac ket qua nghien cim ca ban tren, da xac djnh dugc mdt sd dac tinh cua ram tuoi d am 70,4% nhu: khdi lugng rieng pr = 105kg/m^; h? sd ma sat vcri thep t~ = 0,55 va quan he giira t; sd nen vai dp luc nen Tir kit qua lam ea sd cho viec nghien cim img dung cac loai hinh khai thac xir ly ram, khac TAP CHI CONG NGHIEP NONG THON - SO 12 - 2014 35 ... trinh cat co hai giai doan; dau tien la luoi dao nen ep vat thai mgt doan, roi den cat dut vat thai Trong qua trinh luai dao di vao vat thai phai khac phuc cae lire ma sat luc dan hoi N2 ctia phan... y^u t6 da dugc phan tich cac ngi dung tren, can thiet ke thi nghiem va phan tieh ket qua nghien Trong do: y la goc mai dao doi voi cat rom ciixi de xac dinh cac moi quan he chgn y= 15" IL VAT... 30 25 JO 35 Hinh Dd thi quan he giira lire cdt vd chuyen vi cita dao a cdc mirc gdc cdt Innrt r Trong mgi trudng hgp tren, iing vdi cac gdc cat trugt khac nhau, cac dd thi hinh deu md ta dugc
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