Bdi bdo giai thi0u khdi qudt ve cdc kit qud nghien cicu vi ram tuai vd bd phgn cdi thdi ram lien hgp vdi mdy dgp lua nhu: dgc diim ca ly tinh cua ram tirai cho qud trinh cdt thdi bdng c
Trang 1KET QUA NGHIEN CUU Bp PHAN CAT THAI Mm LIEN HOP VOfi MAY DAP LUA
N H A M KHAI THAC HIEU QUA RUM SAU THU HDACH OT VIET NAM
Nguyin Van Tam ', Li Minh Lu ^, Nguyin Xudn Thiit ^
TOM TAT
Theo irdc tinh moi ndm cd mrac cho ra khodng 46.305 triiu tdn ram (ram vd rg), luang ram ndy din
nay phdn nhieu vdn bi coi la phe phdm, bi dot hogc virt bd ngay trin dong rugng Viec ndy ldm d nhiem mdi
truang vd gdy lang phi rdt ldn nguon tdi nguyin Nghien cuu bg phdn cdt thdi ram liin hgp vai mdy dgp liia
nhdm tgo thudn lgi cho cdc phuang dn xir ly ram da dugc Ihuc hien tgi khoa Ca - Biin, Hgc vien Nong
nghiep Viet Nam Bdi bdo giai thi0u khdi qudt ve cdc kit qud nghien cicu vi ram tuai vd bd phgn cdi thdi
ram lien hgp vdi mdy dgp lua nhu: dgc diim ca ly tinh cua ram tirai cho qud trinh cdt thdi bdng cgnh sdc
dao: lua chgn nguyin ly cat cho bgphgn cdt thdi ram de ddng lien hgp vdi mdy dgp lua; xdy dung bien dgng
cgnh sdc dao ddp ung cdc chi tieu ve cdt thdi tren ca sd ly thuyit cua qua trinh cdt thdi bdng cgnh sdc dao
vd xdc dinh toi uu mgt so thong sd chinh ciia bg phdn cdt thdi rcmi khi lien hgp vdi mdy dgp lua Cdc kit qud
nghiin ciru ndy da bo sung mgt dgng daa mdi vd mot nguyin ly cdt mdi cho bg phdn cdi thdi ram de ddng
liin hgp vdi cdc mdy thu hogch IUa, dong thdi ldm ca sa cho cdc cdng trinh nghien ciru khac lien quan din
ram tuai vd bgphgn cdt thdi cdc vdt lieu tucmg tyr
Tir khod: Mdy thu hogch lua; mdy bdm thdi ram; bg phgn cdt thdi ram; dao cat; cgnh sdc dao
RESULT OF A SCIENTIFIC STUDY ON THE STRAW CHOPPING
PART COMBINED WITH THRESHING MACHINES
FOR THE EFFICIENT EXPLOITATION OF STRAW AFTER RICE HARVEST IN VIETNAM
Nguyen Van Tam ', Le Minh Lu ^, Nguyen Xuan Thiet ^ SUMMARY
An estimated approximately 46.305 million tons of rice straw and stubble was produced nationwide
every year that is considered as waste therefore it was burned or leave immediately in the field This causes
the environmental pollution and leads to a massive waste of agricultural resources In order to facilitate the
straw processing, a study in straw chopping part combined with threshing machineswas conductedat the
Faculty of Engineering, Vietnam National University of Agriculture This paper presents an overview ofthe
study results on fresh straw and the straw chopping part combined with threshing machines involved
characteristics of fresh straw for cutting process by an edge; the selection of principles for the straw
chopping part to combine easily with threshing machines; the establishment ofthe edge profile to meet the
targets on chopping based on the theoretical basis of the cutting process by the edges and determining
optimal parameters ofthe straw chopping part combined with threshing machines.The results of this study
completed a new knife along with a new cutting principle for the straw chopping part to combine easily witli
threshing machines; simultaneously, the resuh is also a basis for further study on fresh straw or similar
materials
Keywords: rice harvester; chopping machine; chopping part; cutting knife; edge
L DAT VANDE
Viec nghien cuu cdc bg phan cdt thai cho sac dao O day nghien cinx vdi vat Hdu cat dgng
cac vat lieu nao do, trudc hdt can nghien cuu vd thd sgi la rom tuoi, do vdy vide xac dinh mdt sd
cdc ddc didm Uen quan vd co ly tinh cua vdt lieu ddc diem ca lytinh cua ram tuai la can thiet
cdt dua tren co sd qua trinh cat thai bang canh Ddi vdi mdi bp phgn cat thai, dieu kien lam
'Truimg Cao ding CO gi*i Ninh Binh T " ^ ==6 ^ huomg dSn viec lira chon nguyen ly
^•^ Hoc vien nong nghiep Viet Nam cat phu hop cho muc dich nghidn CUU Nhu da
TAP CHi CONG NGHIEP NONG THON - SO 19 - 2015 15
Trang 2bidt, d cac co sd san xudt ndm; lam phdn vi sinh;
lam go cdng nghidp thi ram dupc tap trung vd
mdt dja didm cu thd vd thudng dugc cdt vdi cac
nguyen ly cdt dang truydn thdng nhu dao
chuydn ddng tdm kd cd dinh (nguyen ly cdt dang
dao dSa hogc dao dgng trdng), vdi nguyen ly nay
thi rom dugc giii cd dinh trdn bd mat tam kd va
da dupc nen ep trudc khi dugc cat Song, vdi bg
phdn cdt thai ram Hen hpp vdi may dap lua thi
cd didu kidn lam viec nguge lgi vdi khdi rom
dugc cdt theo cac nguyen ly truyen thdng la rom
ludn d trang thai ddng, khdi ram dupc tung ra tiJr
cua ra cua may dap lua vao bp phgn cat, do do
can lira chpn nguyen ly cat cho bd phdn cat thai
ram phii hop khi lidn hpp vdi mdy dap lua
Khi lien hop vdi may dap lua, bd phdn cdt
thai rom cdn dam bdo cdc chi tidu thidt ke dua
tren co sd ly thuydt ciia qua trinh cat thdi cdc vdt
lieu thd sgi bang canh sac dao [8,9], De dam
bao cac chi tidu thidt ke, kha nang lam vide cua
bg phdn cat thai rom phu thudc vao nhieu thdng
sd, trong dd bdn thdng sd vdo dnh hudng chinh
dupc lira chgn la: van tdc cat v(m/s); lupng cung
cap q(kg/s); gdc kep x(do) va khe hd giua dao
va tdm kd (canh ggt) 6(mm), hai thdng sd ra la:
chat lupng cat Cx(%) va chi phi nang lugng
rieng Ne(kW.s/kg) Do vdy, de ndng cao kha
nang lam vide khi lien hgp bd phdn cdt thdi vdi
may ddp lua, ngoai cac chi tieu thidt kd thi can
xdc dinh cdc gia tri tdi uu cho cac thdng sd dnh
hudng chinh (thdng sd chinh) dugc nghien cuu
II PHU'ONG PHAP NGHIEN ClTU
Phuong phap nghien cuu dupc lua chpn: ket
hpp giiia nghidn cihi ly thuydt va nghien cuu
thuc nghiem
2.1 Phirong phap nghidn cmi ly thuyet
Phuang phap nghidn cuu ly thuydt dupc
nghien ciiu dua trdn; co sd ly thuydt cua qua
trinh cdt thai bdng canh sdc dao [7,8,9]; toan hpc
gidi tich; mpt s6 phuong phdp toan hpc trong co
hpc ndng nghiep [l] va phuang phap md hinh
hda md phdng he thdng ky thugt [d]
16 TAP
2.2 Phuwng phSp nghien cuu there nghiem
Bd phgn cdt thdi CTR-1 dupc nghidn cuu thuc nghiem vdi 4 thdng sd vao va 2 thdng sd ra gpi la hai ham chi tidu chdt lugng cdt Cx va chi phi nang lupng ridng Ne dugc xac dinh theo cdng thiic sau:
Cx = 100-^,%;A^^, =^,kW.slkg
Trong do:
- mcd la khdi lupng ciia khdi ram cdt dat c6 chidu dai cac cpng ram < 10 cm;
- mmr la tdng khdi luong cua khdi ram ldy mdu tir khdi rom sau khi qua bd phdn cdt;
- N|b la cdng sudt trung binh tren true trdng cdt vd q la lupng cung cap ram vao bg phdn cdt Phuong phap nghidn ciiu thuc nghidm dua tren: phuong phap quy hoach thuc nghiem don ydu td; phuang phdp quy hoach thuc nghidm da ydu td va phuong phap tdi uu hda tdng quat [2]
De nhdn kdt qua nghien ciiu thuc nghidm cdn co cac dung cu va cdc thidt bi do
Dd do va ghi nhgn ket qua vd mdt sd dac didm CO ly tinh cua ram tuoi, cac thidt hi va dung cu: Cdn didn tii METTLER TOLEDO, Cdn ddng
hd Nhon Hda 5kg, Tu sdy FN 500P, Dung cu do
dp Iuc nen Dung cu do luc cat, Thidt hi ma sat GUNT, Dung cu do ap lire nen dat tren mdy keo nen van nang AUTOGRAPH-AGS-20KNG, Dung cu do luc cat dat trdn may keo nen van nang AUTOGRAPH-AG S-20KNG
Dd xac dinh chi phi nang lugng cdt cdn he thdng thidt bi do md men va cdng sudt: Cam bidn quang OMRON E3F-DS10C4; ddu do momen KSM SDIOOOQA va bp thu thdp xu 1^ sdliduDEWE-3010
in KET QUA NGHIEN ClTU 3.1 Nguyen ly cdt thai cho b$ phan cat thai rom
Vdy dd tan dung va khai thac rom, ra dupc triet de hon, cdn nghien ciiu bd phan cat thai rom cd nguyen ly phii hgp khi Hen hpp vdi may dap Ilia Vdi cac bo phdn cat thai sii dung cac nguydn ly cdt truydn thdng dao chuydn dpng CHl CONG NGHIEP NONG THON - SO 19 - 2015
Trang 3tdm kd cd dinh nhu: nguydn ly cat kidu dao dgng
trdng va nguyen ly cdt kidu dao dgng dia [?] thi
cau tao ddi hdi phai cd cgp 16 cudn va ep khdi
rom trudc khi khdi rom dupc dua vao hgng thai,
lam cho kdt cdu truydn dgng va kdt cdu chung
cua bg phgn cat rat phiic tgp khi lidn hgp bd
phgn cat voi may dap Iua, trdn ca sd nay kdt hpp vdi trang thdi khdi ram dugc tung true tidp vao
bp phgn cdt thai, nhdm tac gid da iua chpn dugc nguyen ly cdt phii hgp khi lidn hgp bd phan cdt thai dugc trinh bay trdn hinh 1
Ciia ra rOm
B6 phan cit thdi rcfm MO hinh lifin hdp b6 phan cat rom vdi m^y dap lua
Hinh 1 Bo phgn cdt thdi ram vd mo hinh lien hap vai mdy ddp lua
1-Trdng cit; 2-Canh gat (tim ke); 3-Than dao c6 dinh; 4 - Tam lien ket; 5 -Thanh ldp dao
De thdng nhat tdn gpi, tac gia ky hidu tdn
gpi cho bp phdn cdt thai rom cd nguyen ly nhu
tren hinh 1 Id "bp phdn cdt thai CTR-1" la
"nguyen ly cat kidu nhieu dao cd dinh"
Bd phdn cdt thai CTR-1 gdm cd: Trdng cat
1 dang hinh tru cd chidu ddi la Lt, ban kinh mat
ngoai la rt, tren trdng cat lap ba hang canh gat
each ddu nhau nhd Hen ket giiia ma Hen kdt 4
cua hang canh gat va mat tru cua trdng cat bang
bu long Hang canh ggt dupc cau tgo bdi cac
canh gat 2 ldp song song, ddng phdng va each
ddu nhau trdn tam lien ket 4, cdnh ggt 2 la thep
tdm ddy 0,004 m, rpng la beg, dai la Leg va dupc
Idp nghidng mgt gdc a so vdi phuang hudng
kinh tgi chdn cdnh ggt Dao cd dinh 3 cd cgnh
sac dang cong dugc thiet kd sao cho qua trinh cdt cd trugt, cac dao cd djnh 3 dugc lap vdi cac cgnh sac cua dao song song vdi nhau va khodng each giiia hai mat bdn cua hai dao kd nhau Id bd nhd thanh dan 5
Nguyen ly hogt ddng: Khi rom dugc tung ra tir ciia ra ciia may dap liia, lugng ram nay dupc tung true tiep vao cira vao ram ciia bd phgn cdt thai, nhd canh ggt 2 khdi rom dugc dua vao viing cat va dupc ep trdn canh sdc cua luai dao vdi mdt dp luc cat can thidt, khdi rom sau khi dugc cat nhd cdnh gat 2 tung khdi ram da dupc cdt ra ngoai qua cira ra cua bd phan cat thai rom
Uu diem cua bd phan cdt thai CTR-I:, + Thuc hidn nguyen ly cat cd trupt, de dang
Trang 4cdt cac vat lieu thd, sgi vd lam cho chi phi ndng
lupng cdt cd gia tri nho
+ Canh gat ldp nghidng mpt gdc a cho phep
vira keo (va) ram vao vimg cat, nen ep va gat
khdi rom trupt trdn canh sdc dao, ddng thdi tung
nhiing phdn rom da dupc cdt ra ngoai
+ Nhd su lien hop vdi bp phan dap liia da
tan dung ngudn ddng ndng ciia khdi ram tir cira
ra cua bd phdn dap Iiia dugc tung thang vao bd
phdn cdt thai CTR-1, qua dd da lam giam chi
phi nhdn cdng cho qud trinh cap lieu khi cat
rom Ddng thdi rom dugc cat ngay sau bd phdn
dap la rom tuoi, ndn chi phi nang lupng cat
giam dang kd so vdi cat khdi rom khd tgi co sd
san xudt
+ Cd the thay ddi chidu dai doan cat bang
each thay ddi bd rdng thanh idp dao 5 va cdc
hang cdnh gat
Nhugc diem cua bd phdn cat thai CTR-1:
Khdng cat dupc nhiing cpng rom cd phucmg
song song vdi cgnh sdc dao, song thuc td rdt it
nhiing cpng rom ma toan bd chidu dai than cgng
ram ddu song song vdi cgnh sdc dao Be khde
phuc nhupc didm nay, tuy theo yeu cdu chidu
ddi dogn cat ma chpn khoang each giiia hai dao
kd nhau bd sao cho phu hgp
3.2 Ket qua ve mot so d^c didm co' ly tinh
cua rom tirffi voi giong lua BC15
Lua sau khi ggt de xdp ddng khdng qua mpt
ngdy, ddc tinh co ly ciia rom bao gdm: dp am;
khdi lugng rieng; he sd ma sat giira rom vd thep;
quan hd gifta ap luc nen qn(N/cm^) va ty sd nen
ep e; quan he giira gdc trugc T va dp Iuc cdt thai
ridng qci(N/cm) hoac cdng cdt thai ridng vd quan
he giOa ap luc nen ben q^b (N/cm^) vdi khe hd 5
do khdi ram da dupc cat chen vao khe hd tgo
bdi mat ben cua dao va mat ben canh ggt Cac
ket qua nghien ciru nay da dupc trinh bay cu thd
theo tdi lieu lidn quan [4], trong dd mdt sd kdt
qud nghidn ciiu ndi bat nhu sau:
- Quan he giiia ty s6 ep tuang ddi Sn va dp
lire ep qn ddi vdi rom tuoi:
Gpi ap luc nen ram Id q„'y N/cm^ hr la chidu
cao ban ddu cua khdi ram d trang thdi tu nhien;
hn dogn giam chidu cao khdi rom khi nen, khi
dd ty sd nen tuang ddi dupc dinh nghia theo
cdng thirc: s„=-^ Kdt qud thi nghidm quan he
giua ap lire nen qn (N/cm^) va ty sd nen tucmg ddi En the hidn tren dd thi hinh 2
Ob thj quan hee -q„
q^jtN/ar^^)
Hinh 2 Dd thi ihirc nghiim vd dd thi hdm hdi quy md td quan hi E„ - g„
TCr sd lidu thi nghiem qua phan tich hdi quy, ham hdi quy md ta quan he giiia ty sd nen tuong ddi En va dp Iuc nen qn vdi he sd tuong quan R^ - 0,9693 nhu sau:
En-0,1644.ln(qn)-0,1335; (1)
- Quan he giiia gdc trupc x va dp lire cat thai ridng qct hay cdng cdt ridng Ar dupc trinh bay trdn dd thi hmh 3 hodc cdc cdng thitc (2) vd (3)
Do t h j quan he qct - T
: 0 8045*;
-Tidfl}
D & t h | q u a n h ^ A r - T
= lE-05x' • 0 OOllx^ + 0-0287»i + 1.4493
i y ^ g S - ^ V - a j //
l ^ r m i n + 6 % A r m i r ) - ' ^ \ ^ - -^Jg^
j Armin — "
1 1 i ,T{fl6)
18
Hlnh 3 S\(phu Ihudc cua qa va A, voir
Trang 5£Jcf= 87,65-0,8045 T;jV/cm fl= = 0,9245; (2)
i^=10-5.T3-0,0011.T^0,0287.T-1-1,4493; i?2 = 0,9717; (3)
Tir kdt qua do trdn va phuang trinh (3) cd
the thiet kd dao thai sao cho qua trinh cdt cd
cdng rieng nhd nhdt hoac tuong ddi nhd, theo
[7] gia tri gdc trupt T dupc ldy sao cho cdng cdt
thdi ridng Acr nam trong khoang tir Acrmm ddn
Acr = Acrmin+ 6 % A c ^ n = 1,45J/cm^ voi A „
= 1,45 J/cm^ thay vao phuong trinh (3) dupc hai
gia tri gdc trugt imin = 43'^ va Xmax = 67° Trdn dd
thi hinh 3 khoang tir x^m "^ tmax la vung gia tri
gdc trupt hgp ly cho cdng cat ridng cd gid tri
tuong ddi nhd Vdy trong thidt kd bp phdn cdt
thai theo nguyen ly cat kidu nhidu dao cd dinh
gdc trucrt hpp ly duoc thidt kd trong khodng
T = 4 3 ' ' ^ 6 7 ^
- Quan he giira dp luc nen bdn qnb va khe hd
5 dupc nghidn ciiu thi nghiem vdi 5 muc khe hd
khac nhau cho ket qud trinh bay bdng dd thi
hinh 4 va cdng thiic (4)
q^b = -18,915.6 + 146,38; (N/cm^) ; (4)
vdi 5< 5 mm; trong dd: khe hd 5 cd don vi; mm
qnbCN'cm') Dd thi quan he Qnt - 5
Hinh 4 Anh hudng cita khe ha 5 din q„h
Nhgn xet: Vdi cac kdt qud nghidn cuu tren,
da xdc dinh dugc mpt sd dac didm lien quan vd
CO tinh ciia rom dnh hudng ddn qua trinh cdt
ram: quan he giua gdc trupt vdi ap lire cdt thai
rieng va cdng cat ridng; quan he giiia khe hd ciia
dao va tara ke vdi luc ma sat cua khdi ram da
dugc cat tac dung Idn thdnh bdn ciia dao Kdt qua
nghien ciiu cho thdy, vdi nguydn ly cdt kidu
nhidu dao cd dinh, canh gat chuydn ddng ggt va
nen khdi rom trupt trdn canh sac dao, gdc tru'pt
TAP CHi CONG NGHIEP NONG THON - SO 19 •
T = 43 -^ 67 la vimg gdc trugt hop ly cho cdng cat ridng Acr tuang ddi nhd Do dnh hudng ciia lire ma sat vao thanh bdn ciia dao, khi chd tgo bd phan cdt thai rom theo nguyen ly nay khdng nen chpn khe hd 6< 1 mm, khe hd 5 cd thd chgn ^ a nghidn cim trong viing 6 = 1 -f 5 mm
3.3 IVlQt so ket qua nghien cihi ly thuyet
- Kdt qud xdy dung bidn dgng canh sdc dao:
Vdi mdi nguydn ly cat nhdt dinh, bidn dgng canh sac dao cd anh hudng ldn ddn chdt Iupng cat va chi phi ndng Iugng ciia bd phdn cdt:
Mdi mdt bien dang cgnh sac dao khi dugc thiet kd che tao, xet vd mat khoa hgc khdng chi dam bdo didu kien cat tdt, md cdn ddi hdi phdi cd radt ban thuydt minh vd co sd tinh toan ndng Iugng cho bd phan cat thai Vdi cdc dao Iam vide
d cac nguydn ly cdt truydn thdng dang dao trdng
va dgng dao dia trong dd dao chuydn ddng thi rad hinh khao sdt tinh toan ndng lugng cho bd phdn cdt da dugc rapt sd tac gid [7] trinh bay cu thd
Ddi vdi bg phdn cat thai rom CTR-1 lidn hgp vdi may dap lua cd nguyen ly cdt trinh bay tren hinh 1 thi canh sac dao cd dang cong, canh sdc hudng vd phia Idm, khi cdnh gat nghieng mdt gdc a so vdi phuang hudng kinh ciia trdng cdt, khi do trong qua trinh cat se tao ra hai loai gdc la gdc quay trdng cdt (p va gdc cue 0 (hinh 5)
Hmh 5 Mo hinh xdc dinh hdm vec to bdn kinh cue
R(6) lheo goc quay rp
Viec khao sat xac dinh chi phi nang Iugng bd phdn cdt thai dugc thudn Igi klii ban kinli cue
2015 19
Trang 6R(e) dugc xac dinh Voi nguyen ly cat nliieu dao
CO dinh neu su dung biSn dang c£inh sic dao co
dang cung tron lecll tam tlii viec xac dinh R(G)
theo goc quay trong cat 9 rat phurc tao va gan
nhu idiong xac dinh dugc, ben canh do diSu Icien
trugt g cuoi dai d o ^ cat khong dugc thuan lgi
tlic la goc trugt x ty IS thuan vol chieu dai ban
kinh cue R(0)[5] De khac phuc mgt so van de
tren, bien dang canh sac dao cho bg ph^n cat thai
CTR-1 da dugc xay d\mg theo bien dang duong
xoan 6c logarit co dac di§m g6c trugt x khong
d6i trong qud trinh cat dugc trinh bay tren cong
thiic (5)
RC((.)= R„,r'-"«=<'5i(m) (5)
Trong do: Ro - ban kinh dau canh sSc dao
hay dau canh gat, m; cp- goc quay cp cua tr6ng cat,
rad; i - goc trugt, rad
Nha canh sac dao dugc xay dimg theo cong
thiic (5) tim dugc quan he giiia goc cue 6 theo
goc quay (ptrinh bay tren cong thiic (6) va xac
dinh dugc ban kinh cue R(6) theo cong thiic (7)
hl-Crad) Trong do:
!
a, = (cotg2(T).e''-""sM+0,992668)
b, =cotg(T).e»"'BW-0,98B55.ctitg(Y) ;
c, = 2 e " ° « t 3 -0,0014S9.cotg(Y;-1,999928
R(B) = R„,e-«'""*';(m) (7)
Ban kinh cue R(8) dugc xac dinh theo goc
quay (p la goc quay de dang xac dinh theo goc
quay cua nguon dgng luc, ket qua nay lam co so
de xay dung mo hmh toin mo ta anh huong cOa
cac thong s6 chinh djn cac ham nang lugng cua
bg phan cat trong qua trinh cit
- Mo hinh toan mo ta anh huong ciia cac
thong s6 nghien cihi chinh dSn ham chi tieu dac
trung cho chi phi nang lugng ciia bg phan cat thai
CTR-1:
Vol nguySn ly c5t kiSu nhiSu dao c6 dmh, ta thay trong giai dojin cat khoi rom luon dugc phan thinh 2 phan trong vvmg cat (vung canh sac dao): phan khdi rom da dugc cat co kh& Iugng m„(kg) nSm phia duoi canh s i c dao va ph&i kh6i rom chua dugc cat co khoi lugng mrt nim phia tren vd trugt theo quj* dao canh sic dao Mo hinh toan dugc xay dung dg:a vao viec xic djnh cac thanh phin luc tac dung vao cac phin kh6i rom da cit m,5 va chua cit mn dugc trinh bay theo hinh 6 va hinh 7
(6)
Hinh 6 Phdn tich cdc thdnh phdn l\rc tdc dung vdo phdn khdi ram chua cdt
Hinh 7 Phdn tich cdc thdnh phdn luc tdc dung vdo phdn khoi ram da cdt
+ Luc canh ggt cdn thidt thuc hien cdng dogn
nan va cat phan khdi rom chua cdt:
Phan khdi ram chua cdt giai ddu va phu kin tren be mat dogn QCi ciia canh ggt, do khdi ram chua cdt bi cdt tgi vj tri giao didm Q ndn trong CHl CONG NGHIEP NONG THON - SO 19 - 2015
Trang 7tinh todn ly thuydt cd thd coi khdi lugng phdn
khdi rom chua cdt mrt dugc cdt tdi giao diem Q
Ddi vdi phdn khdi rom da cdt khdng chiu dnh
hudng cua canh sdc dao ma chu ydu chiu anh
hudng cua cac lire ma sat do khdi rom vdi mat
ben than dao va thanh dan ram lap dao, do dd
khdi lugng phdn khdi ram da cat trong tinh toan
dugc quy ddi ddt tai vi tri trung didm cua doan
GlQ trong viing cat
Cac thdnh phan lire tac dung vao phan khdi
rom chua cdt bao gdm: lire cat thai do cgnh sac
dao thuc hien cdt ram Pet; luc ndn ep khdi rom ddn
trgng thdi cdt Pnib; l\ic can khdng khi Wo; luc ma
sat giiia rom va hai mat vat cgnh sac dao F,nsd;
trgng Iugng phdn khdi rom Pn; luc quan tinh ly
tdm Fqn va luc quan tinh tidp tuydn Fqt do khdi
rom chuydn ddng theo quy dgo canh sac dao
Khi khdi rom chiu tac dung cua cac luc,
khdi rom se tac dung vao canh gat tao ra cac
phdn Iuc tir canh gat tac dung vao khdi ram de
thuc hidn cdng doan nen cdt rom Gpi Fmsi va
Qnc Id phan lire canh gat tac dung vdo khdi rom
theo hai phuong (hinh 6), su dung nguyen ly
Dalambe chidu tdt ca cdc luc va phan luc len
phuang cdnh ggt va phuang Uc-Uc dugc phdn luc
cdnh gat tac dung len rom la:
Fmst = (Pet + Pn.b PTt).sin((po + 0 t + x) + (Fq,
-Fmsd) cos(x) - Wo.sm(T ~ X) - F<,„.sm(x); (N) (8)
Qnc ^ (Pc + Pnib Prt).COS((po+ 6 T + x ) + (Fnsi
-Fqi) sin(x) + Wo.cos(T - X) ; Fqn.cos(x); (N) (9)
+ Luc canh ggt cdn thidt thuc hien ddy phdn
khdi ram da cdt ra ngodi vimg cat:
Do dnh hudng ciia thdnh phan lire ma sat
gifia khdi rom da cat vdi hai mat bdn cua hai
dao kd nhau va thanh lap dao, do do khdi ram
khdng trugt trdn bd mat canh gat, vdy cdc lire
tac dung ldn khdi rom bao gdm: Luc can khdng
khi Wos, luc ma sat do khdi ram da cat vao hai
mat bdn cua dao Tmsd cd phuang HR-UR vudng
gdc vdi Rt; luc quan tinh I^ tdm Rqns c6 phuang
theo phucmg Ri (d day khdng cd luc qudn tinh
theo phuang tidp tuydn do gia thidt cdnh gat
quay ddu); trong lugng Pts cd phuang thdng
dling; phan lire Fm va ma sat Fmsid do thanh ldp dao tac dung vdo khdi rom va phan luc tir canh gat tac dung vao khdi rom Fmss, Qdr 1^ lupt theo phuong canh ggt va phuang Uc-nc
Cdc gdc chidu ciia cdc thanh phdn lire ldn phuang UR-nRva ban kinh Ridugc xac dinh theo
sa do hinh 7, thanh phdn luc ma sat vdi mat ben dao Tmsd dugc xac dinh qud dp lire ma sdt ben nghidn ciiu tai phdng thi nghidm, tir do sir dung nguydn ly Daldmbe chidu tdt cd cac luc va phdn luc ldn phucmg canh gat va phuang Uc-Uc dugc hai phuong trinh cdn bdng va xac djnh dugc hai thdnh phan phan luc Fmss va Qdr:
Fmss = (Wos + Tmsb + Fms,(,).sin(Po) + (Ft,ns
-F,d).cos(Po) + P, sin(P,); (N) (10)
Qdr = (Wos + Tmsb + Fnistd).COS(po) " (Fqns "
F,d).sin(Po) + Pr3.cos(P,);(N) (11) Cac lire tac dung vdo khdi ram da cat va chua cdt dugc xac dinh vd trinh bay trong tai lieu [5].Sir dung cac cdng thiic tinh Fmst, Qncl Fmss; QdfVd bdn kinh cue R(8) lam co sd dd tinh
md men can tren true trdng cdt do cdng dogn nen cdt vd day ram trong giai dogn cdt gay ra
Mat khac vd phdi ciia cdc cdng thiic (8; 9; 10 va 11) vdi cac bieu thuc xac dinh cdc luc tac dung
cd chiia cac thdng sd nghien cuu chinh Id: van tdc cdt v; Iupng cung cap q; gdc kep x va khe hd
8, do vdy dd tidn cho viec theo doi, ham md men can tren true trdng cdt Md trong giai dogn cat dupc vidt dudi dgng ham phu thudc trinh bay trdn cdng thiic 12
Mc, = f(t; Q; v; q; %; 5); (N.m) (12)
Trong dd: t va G la thdi gian va gdc cue xdc dinh vi tri dang thuc hien cdt tren canh sdc dao
Bidu thiic (12) dugc gpi la md hinh toan md
td anh hudng cua cac thdng sd ddn ham md men can tren true trdng cdt dac trung cho cac ham chi phi ndng lugng ciia bd phan cdt
Sau khi xdc dinh dupc md men cdn trdn true trdng cat d timg giai doan trong qud trinh cat, tit
dd xdc dinh dugc md men can trung binh trong mpt qud trinh cat; cdng suat va chi phi nang lugng rieng Ne ciia bd phan cdt Vdi kdt qua
Trang 8nghien ciiu nay cho phep ngudi nghien ciiu cd
thd khao sdt mirc dp dnh hudng cua timg thdng
sd chinh ddn gid tri cac ham chi tidu Iam co sd
cho dinh hudng thidt kd bp phan cat thdi phuc vu
cho nghidn cuu thuc nghidm va thidt ke che tgo
bd phdn cat CTR-1
Kdt qua khdo sat md hinh todn khi thay ddi
cdc miic eua cac thdng sd chinh anh hudng ddn
cac ham ndng lugng dupc trinh bdy bdng do thi
hinh 8
Tir kdt qua khdo sdt ta cd dnh hudng ciia
timg thdng sd ddn gia tri cac ham ndng lugng
bang phuang phdp nghidn ciiu ly thuyet nhu sau:
Anh hudng cua van tdc cdt v: khi v tang md
men trung binh Mtbtren true trdng cdt gidm la do
lire cat thai giam, kdt qua nay phu hpp vdi kdt
qud thuc nghidm trong 1^ thuydt cdt thdi bdng
ludi dao (N.E Reznhik) Song vgn tdc gdc tdng
lam cho cdng sudt trung binh N^ va chi phi nang
luong rieng Ne tang
Anh hudng cua Iugng cung cdp q: khi q tdng
thi khdi lupng va m^t dO rom trong viing cdt tdng ldm tat cd cac thanh phdn ly:c tang, do dd lire cdt thai tang nen Mtb vd N,b tdng, song theo cdng thiic (2.2) Ne ty Id nghich vdi q ndn khi q tdng thi
Ne lai giam
Anh hudng cda gdc kep % vd khe hd 5: khi
X tdng Iam gidm khd ndng nen dp, tang khd ndng trugt khdi ram tren canh sdc ciia dao Idm cho lire cdt thai gidm Cdn khi 5 tdng lam giam kha nang ndm khoi rara vao khe hd 5 ddng thdi lire
ma sat do ram da cdt vao thanh ben dao ciing giam, kdt qua Idm cho luc cdt thdi giam Kdt qua khi X va 5 tang thi gia tri cac ham ndng lugng deu gidm
Tir cdc kdt qud va nhdn xet tren, qua trinh xdy dyrng md hinh toan va khao sat anh hudng cua cac thdng sd chinh ddn cdc ham ndng lugng
da cho bidt quy ludt bi^n thien cua cdc ham ndng lugng khi thay ddi cac miic cua cac thdng
so chinh
ADII tturong c
k W * k W s / k e
Anit hudng ciia x(d^)
''kivj/kg
Anh huffng ciia ci(kg/s}
^ ^ ^ —
^r:7^rr'"^
Anh hudng cun 6(Tnni)
kW.s/kg
Hinh 8 Anh hudng cUa thong so chinh den cdc hdm ndng lugng
Trang 93.4 Ket qua nghien cuu thyc nghiem
Kdt qud nghidn ciiu ly thuydt chi xac dinh
dugc miic do dnh hudng ciia cac tiidng sd
nghien ciiu chinh ddn ham chi tidu chi phi ndng
lupng ridng Ne cua bg phdn cat va khdng khao
sat dupc anh hudng cua cac thdng s6 chinh ddn
ham chi tidu chdt Iugng cat Cx Nghidn ciiu thuc
nghiem cho kdt qua ddnh gid anh hudng cua cac
thdng sd chinh ddn ca hai ham chi tidu ddng thdi
tim ra gia tri tdi tu cho cac thdng sd chinh, ddm
bao cho bp phdn cdt thai lam vide hieu qua va
thirc tidn han
Kdt qua nghidn citu thuc nghidm don ydu td
xdc dinh anh hudng dgc lap cua tung thdng sd
ddn hai ham chi tieu da dugc trinh bay [3] Tir
dd nghidn cim thue nghiem da ydu td va tdi uu
tdng quat cho kdt qua nhu sau:
- Muc do anh hudng ciia cac thdng sd chinh
ddn hara chi tidu chdt lugng cdt trinh bay bang
ham chi tieu dang thuc theo cdng thiic (13) va
dgng chinh tdc theo cdng thuc (14)
Cx = -134,995 + 1 l,779.v + 99,534.q + I,660.x
+ 2,486.5 0,202.v^ + l,8.v.q
0,02.v.x0,13.v.5 124,625.q^ 0,833.q.x+ ll,417.q.5
-0,009.x^-l,346.5^ (13)
Ol - 98,06 = -0,203.v^ - 124,889.q2 - 0,008.^^
- 1,08.5"; (14)
- Mlic do dnh hudng ciia cdc thdng sd chinh
ddn ham chi tieu Ne trinh bay bang ham chi tieu
dgng thuc theo cdng thiic (15) va dgng chinh tdc
theo edng Ihiic (16)
Ne = 16,157 - 0.922.V + 5,986.q + 0,088.x '
1,011.6 + 0,0178.v^ - 0,047.v.q - 0,0008.v.x +
0,008.v.5 4,867.q^ 0,024.q.x + 0,492.q.5
-0,001 -x^ + 0,005.x.5 + 0,021.8^; (15)
Ne - 4,876 = 0,018.%?^ - 4,879.q2 0,001.-7"
+ 0,034.5'; (16)
Ham tdi im tdng quat dupc xdy dung blng
each xdy dung ham tdng tir (13) va (15), dimg
phuang phap tdi uu hda cue tri c6 didu kidn
Kdt qua xac dinh gia tri tdi uu trinh bay trdn
TAP CHi CONG NGHIEP NONG THON - SO 19 - 2015
bang, ham chi tidu Y| (Cx) chpn dieu kien Max trong vimg didu kifn Y, > 92%, ham chi tieu Y2 (Ne) chgn didu kien Min trong todn midn quy hoach Dd thi mat chi tieu tdng quat dugc trinh bay trdn hinh 9
Bdng Toa dg diem toi uu long qudt
, Multiple Response Opbmiiat'on Optio
RespOfUQ
Yl Y2
T h o n g
so
X!
X2 X3 X4
Low
25 0.5
35
7
m
| £ 7
H i g h
30 0-7
55
4
KiGh
| 5 «
Gia tli
toiuu 27.9134 0.58272 49,6183 2.51299
" M«^
r M«.f
H i m muc tilu
Yl Y2
Gia tti toiuu 95,183 5,07709
Estimated Response Surface X3=45.0,X4=3.0
XI
Hmh 9 Mgl chi lieu tdng qudt
Kdt qua nghidn ctru thuc nghiem xac dinh dugc gid tri tdi uu ciia cdc thdng sd vdo cho kdt qua chdt lupng cdt cd gid tri cao Cx = 95,18%
va chi phi ndng Iupng ridng phu hgp Ne = 5,08 kW.s/kg vdi dp tin cay 95% la: van tdc cat v = 27,91 m/s; Iupng cung cdp q ^ 0,58 kg/s; gdc kep X = 49,62**; khe hd 6 = 2,51 mm Kdt qua nghidn ciiu nay lam ca sd thiet ke, chd tao bp phdn cat thai rom lien hgp vdi may dap Iiia, dap img nhu cdu thuc tien trong cdng cupc khai thac
va xir Iy rom, ra sau thu hoach
23
Trang 10IV KET LUAN
Kdt qua thi nghidm xac dinh cac ddc tinh ca
ly cua rom tuoi va mdi quan he giiia cac tham
sd anh hudng ddn qua trinh cdt thdi bang ludi
dao lam ca sd iing dung cho md hinh tinh toan
ly thuydt va la tai lieu tham khao cho cac cdng
trinh khac lien quan ddn rom tuoi hay cdc vdt
lieu tuang tu
Nguyen ly cdt kidu nhidu dao cd dinh id mdt
nguyen ly mdi, vdi canh gat chuyen ddng thuc
hidn vo rom, nen ep va ddy khdi rom trupt tren
canh sdc dao ddn trgng thdi dugc cdt ddng thdi
tung khdi ram da dugc cdt ra ngoai.Do dd ndng
cao dupc ndng sudt vd gidm chi phi ndng lugng
cho qud trtnh cdt thdi ram, de dang lien hgp vdi
may dap Iiia dp dung vao thuc tidn sdn xuat
Kdt qud nghien ciiu 1^ thuydt xay dimg dugc
bidn dang canh sdc dao cd dde diera la gdc trugt
T khdng ddi trong qud trinh cat, tir dd xdy dung
dupc md hinh todn tinh todn ndng Iugng bg phdn
cat thai vd khdo sat anh hudng cua cac thdng sd
nghidn ciiu ddn cac ham ndng Iupng cho bd phan
cdt thdi CTR-1 Day Id mdt ddc diem ndi bat vdi
phuong phap tinh mdi, cd the xac dinh dugc mpi
thdng sd d bat ky vj tri nao tren canh sdc dao
hay tai mpi thdi diem trong qua trinh cat
Bang nghien ciiu thuc nghiem da yeu td da
xay dung dupc hdm hdi quy thuc nghiem bidu
dien mdi quan he giua cac thdng sd chinh va cdc
ham chi tidu Qua do, bang phuong phdp tdl uu
tdng quat dd xdc dinh dugc gid tri tdi uu cua 4
thdng sd chinh, cho chat lupng cdt cd gia tri cao
Cx = 95,183% va chi phi ndng lupng ridng cd gia
tri phil hpp Ne = 5,08 kW.s/kg la: v = 27,91 m/s;
q = 0,58 kg/s; x = 49,62° va 5 = 2,51 rara Kdt
qua nay eimg vdi cac thdng sd cdu tgo dugc xac
dinh trong nghien ciiu ly thuyet lam co sd chd tgo
bd phdn cdt thai rom lidn hgp vdi may ddp Iua
ling dung vao thuc tien sdn xuat
Tai li|u tham khao
! Trail Thi Nhi Hudng va Dang The Huy (1987) Mot so phuang phap todn hpc trong co hpc nong nghiep, Nha xuat ban Nong nghiep Ha Ngi
2 Pham Van Lang va Bgch Qudc Khang (1998) Ca sd ly thuyet quy hogch thirc nghiem va ling dung trong ndng nghiep, Nha xuat ban Nong nghiep Ha Ngi
3 Nguyen Van Tam, Le Minh Lu va Nguyen Xuan ThiSt (2013) Ket qua thi nghiem dan y6u t6 ciia mot so thdng sd ciia bp phgn cdt thai ram lien hpp vdi may dgp iua Tap chi Khoa hpc va Phat tridn, 11(5): 735-744
4 Nguyen Van Tam, Le Minh Lu va Nguyen Xuan Thidt (2014) Kdt qua thi nghiem xac djnh mot
sd thdng sd phy thuoc vao ddc tinh ca \^ cua ram
tuai trong qua trinh cat Tap chi Cdng nghiep nong thon, (12): 27-35
5 Nguyen Van Tam (2015) Nghien ciiru mpt so thong so chinh lam ca sd thiet ke bp phgn cat thai rem lien hgp vdi may dap lua, Luan an tien sT ky thugt, Hpc vi?n Nong nghiep Viet Nam, 157 tr
6 Biii Hai Trieu (2009) Md hinh hda va md phong he thong ky thugt, Bai giang cao hpc, Trudng Dai hpc Ndng nghiep Ha Noi
7 Tran Minh Vupng va Nguyen Thj Minh Thuan (1999) May phuc vu chan nudi, Nha xuat ban Giao due
8 MejibHHKOB, C B (1978) MexaHH3auHa H
a B T 0 M a T H 3 a U H f l aCHBOTHOBOflieCKHX ^'^P'*^' JleHHHrpaflCKoe OTAejieHne, Kojioc
9 PesHHK, H.E (1975) Teopna pesauHfl jie3BHeM H ocHOBbi pacMCTa pejKymHx annapafOB MaiuHHcxpoeHHe, MocKsa
Ngay nhan bai: 02/5/2015 Ngay phan biln: 18/5/2015 Nguoi phan bi^n: TS Doan Xuln Thin, Hgi co khi nong nghiep Viet Nam