Hgn che truyen nhiet ra mdi trudng xung quanh nhdm tgo diiu kien thudn lgi cho viec hinh thdnh hdn hgp chdy cung cdp cho ddng Cff Doi vai dpng co xang thi viec tao hSn hgp chay dupe
Trang 1NGHIEN ClTU GIAI PHAP HOAN THIEN XE ALL STAR 2017 - VNUF
THEO H U 6 N G GIAM TIEU HAO NHIEN LIEU
Dang Thi Ha, Le Van Thai
Trudng Dai hgc Ldm nghiep
TOM TAT
Bing phu'ong phap nghien cuu ly thuySt, bin bao trinh bay ca set khoa hoc ciia viec dua ra cac giai phap cai tiSn dpng CO xe may Wave Anpha 1 lOcc theo huong giam tieu hao nhien li^u Tinh toan lua chgn he thong truyen
luc voi ty s6 truygn hop ly, dap iing yeu ciiu vk dieu kien keo, bam ciia xe khi chuySn dong dong thoi dam bao
v6 t6c do cua cuoc thi theo quy dinh Thiet ke khop noi tu dong mot chieu de truyen mo men xoan cho banh xe chu dong nh5m nang cao hieu suit truygn lite Thiet ke hinh dang khi dong hpc cua xe sao cho luc can khong khi tac dung len xe ta nho nhat nham giam lupmg nhien lieu tieu hao khi xe chuyen dpng tren duong vai dp dai nhat dinh KSt qua nghien cuu dat dugc lam co so cho viec cai tien hoan thi?n xe All Star 2017 - VNUF theo
huong tiet kiem nhien lieu nham nang cao thanh tich cua xe phuc vu cupc thi "Lai xe sinh thdi, tiet kiem nhien liiu" do Honda to chuc hang nam tai Viet Nam
Tu khoa: All Star 2017, he thong truyen lyc, khdp noi tu dong mpt chieu, Ui xe sinh thai - tiet kiem nhi^n lieu, tiSu hao nhien lieu
1 D^T VAN BE
Cuoc thi "Lai xe sinh thai, tiet kiem nhien
lieu" dugc Honda Nhat Ban bat dau to chiic tu
nam 1981, den nam 2010 cuoc thi dugc to
chuc lan dau tai Viet Nam voi 10 dgi tham gia
Cugc thi da tao co hgi quy bau cho sinh vien
cac truang ky thuat phat huy tu duy sang tao ve
ky thuat, cong nghe, dua cac y tucmg vao thuc
te, gop phan vao viec day manh phong trao tiet
kiem nhien lieu va bao ve moi truang song
Honda Viet Nam cung cap cho cac dgi tham
gia cugc thi dgng co Wave Anpha llOcc kieu
mai, tiet kiem nhien lieu va dang dugc sir dung
tren cac dong xe so do Honda Viet Nam san
xuat Cac dgi tham gia se su dung dgng ca nay
de che tao xe theo y tuong cua minh nhimg
phai tuan thu theo quy dinh cugc thi Day se la
su canh tt-anh lanh manh ca v6 y tuong thi^t kk,
ky thuat che tao va ky nang lai xe Trong cugc
thi, cac thi sinh se phai van hanh xe tren quang
duong dai 9,5 km vai yeu cm van tfic trung
binh cua xe phai dat toi thi8u 25 km/li Hieu
suat tieu hao nhien lieu (km/lit) se dugc tmh toan
dira hen lugng nhien lieu tieu hao thuc t^ h-en
chieu dai duong dua theo quy dinh va dpi nao dat
thanh tich cao nhat se la dgi chign th^ng
Tnrdng Dai hgc Lam nghiep da tham gia
cugc thi lan dau tien vao nam 2017 voi muc
dich la dua sinh vien nganh ky thuat ca khi va
nganh cong nghe ky thuat 6 to hoi nhap voi sinh vien cac truang ky thuat trong nuoc va tao
CO hgi cho sinh vien tu duy sang tao, ap dung nhiing y tuong thiet ke moi vao thuc te va hgc hoi sinh vien tir cac truong khac De chuan hi cho cupc thi, truang da thanh lap hai dpi tuyen,
do la KTCK VNUF va dpi All Star 2017 -VNUF Cac dpi da tich cue nghien ciiu dua ra
y hrong thiet ke, che tao va lap rap thanh cong hai mau xe tu che de tham gia cugc thi dugc to chuc Ket qua la ca hai man xe deu hoan thanh cugc thi voi thanh tich con kha khiem ton De huong tai thanh tich cao hon cua Truang Dai hgc Lam nghiep tham gia o cac cugc thi nhung
nam tiep theo thi viec "Nghien cdu hodn thien
xe All Star 2017 - VNUF theo hwdng gidm tieu hao nhien lieu" la can thiet va co y nghia
thuc tien cao
2 PHUONG PHAP NGHIEN CUtJ 2.1 Phirffng phap k§ thiia
Thu thap, suu tam cac tai lieu chuyen mon lien quan toi cac cugc thi xe tiet kiem nhien lieu va ly thuyet dpng co dot trong, ly thuyet 6
to may leo de lam ca so cho viec nghien ciiu ly thuyet de xuat giai phap thiet ke cai tien xe
2.2 Phuffng phap nghien ciru Iy thuyit
Su dung ly thuyet ve dgng co d6t trong, ly thuyet 6 to may keo de dua ra cac giai phap thiet k6 cai tien dpng co theo huang nang cao
TAP CHI KHOA HOC VA C 6 N G NGHE LAM NGHIEP SO 2 - 2019
Trang 2hieu suat tieu hao nhien lieu
3 K E T QUA VA T H A O LUAN
3.1 Nghien cihi cai tign nang cao hieu suat
cho dong Cff
3.L1 Hgn che truyen nhiet ra mdi trudng
xung quanh nhdm tgo diiu kien thudn lgi
cho viec hinh thdnh hdn hgp chdy cung cdp
cho ddng Cff
Doi vai dpng co xang thi viec tao hSn hgp
chay dupe tien hanh ben ngoai xi lanh nho bg
che hoa khi (dgng co dimg che hoa khi) hoac
nho voi phun phun nhien lieu o dang suong mu
de hoa trpn voi khong khi a truoc van nap (loai
phun xang dien hi) De tao di6u kien thuan lpi
cho viec hinh thanh hon hgp chay (xang hoa
hon voi khong khi sach a dang hoi) thi dpng co,
phai tich san mgt nhiet luong de tao dieu kien
cho xang de hoa hoi khi nap vao buong dot
Khi dgng co dot trong lam viec lien tuc
trong thai gian dai thi viec thoat nhiet cho
dgng CO la rat can thiet vi nhiet do trong buong
dot CO the len den ngan do Neu nhiet dp nay
qua cao thi nhien lieu se bi hoc chay truac thai
diem can thiet, anh huong rat 1cm tai sy sinh
cong va kha nang lam viec ciia dpng co Nhiet
do cao se lam cac chi tiet von bang kim Ioai
cua dpng CO no ra, lam giam khe ho, tang ma
sat, gay bo ciing pit tong trong long xi lanh Vi
the de giam nhiet dp trong dpng co xuong thap
hon nhiet dp giai han, ban than dgng co da
dugc thiet ke he thong lam mat bang khong khi
vol cac canh tan nhiet
Tuy nhien voi dac thu van hanh xe trong
cugc thi lai xe sinh thai tiet kiem nhien lieu la
cho dpng CO no va tang toe dat toi toe dp cao,
sau do tat dpng co cho xe tha troi theo quan
tinh ve toe dp nho nhat theo quy dinh cua cugc
thi (V = 25 km/h) Sau do lai de no tang toe roi
lai tat may va cii lap di lap lai nhu the cho den
khi xe thi dau di dii so kilomet quang duong
dua ciia cugc thi theo quy dmh (khoang hon 20
phut) Voi thai gian ngSn nhu vay thi nhiet dp
trong dgng ca chua cao do vay de Ipi dung
nhiet do ciia dgng ca tao hon hop chay chk
lugng t6t thi chn thiSt phai han chg truygn nhiet
tir trong dpng co ra moi trucmg xung quanh
bang cac giai phap:
- Ckt loai bo toan bg cac canh tan nhiet tren than dpng co dk han ch^ thoat nhiet trong dgng
CO ra moi trucmg xung quanh;
- Lpi dung nhiet dp ciia luong khi thai de lam nong duang 6ng nap, tao dieu kien thuan lpi cho viec tao h6n hgp chay truoc khi nap vao trong xi lanh
3.L2 Gidi phdp ddt chdy hodn todn hdn hgp chdy
Khac voi dgng co diezel ve phucmg phap d6t chay h6n hgp trong xi lanh, dpng co xang dung phuong phap dot chay cuang biic, nghTa
la sir dung bugi bat tia lua dien tai thoi diem cuoi ky nen va each diem chet tren mpt goc danh lua som Vi the, de tao dugc tia liia dien manh de dot chay hoan toan hon hpp chay trong xi lanh, giai phap la sir dung hai bugi noi song song voi cuon day cao ap ciia bo bin danh lira
3.1.3 Ndng cdo dp sudt cudi thdi ky nen
Ap suat va nhiet dp hon hgp chay 6 cuoi ky nen trong xi lanh tang lam cho cong suat dpng
CO tang, chi phi nhieu Heu rieng va hao ton do mat mat ma sat trong dgng co se giam Mat khac, ap suat va nhiet do hon hpp chay cuoi ky nen trong xi lanh phu thupc dang ke vao ty so nen cua dpng ca va dupe xac dinh theo cong thiic (Nguyin Diic Phu, 1979):
P^ =P^.£"' va T^ =?;.£"'"' (1)
Trong do:
Pa, Ta - ap suat va nhiet dp cuoi ky nap;
£• - ty so nen cua dpng co;
ni - chi so ducmg nen
Nhu vay, de tang ap suat va nhiet dp hdn hgp chay cuoi ky nen nham phat huy cong suat dpng CO va giam chi phi nhien lieu rieng can thiet la nang cao ty so nen len cao nhat co the
Ti so nen s cua dpng ca la ti so the tich cua khong gian trong xi lanh khi pit tong di xuong diem chet duoi (the tich toan phan) voi the tich khong gian trong xi lanh khi pit long di len diem chet tren (the tich buong dot) va dugc xac dinh theo cong thiic:
K + K
-\ + v,^ (2)
TAP C H I KHOA H O C VA CONG NGHE LAM N G H I E P SO 2 - 2019 113
Trang 3Trong do: Vtp - the tich toan phan; Vc - the
tich buong dot; Viv - the tich lam viec
Tit cong thirc (2) ta thay: Muon tang ty so
nen e ta co the tang the tich lam viec cua xi
lanh hoac giam the tich buong dot trong xi
lanh Tuy nhien ta khong the tang the tich lam
viec cua xi lanh do kich thuoc tay bien, tay
quay true khuyu dpng ca la khong the thay doi
Vi vay ta chi c6 the tac dgng bien phap ky thuat
de giam the tich buong dot trong xi lanh ciia
dpng CO (giam Vc) bSng nhung giai phap sau:
- Giam chieu cao buong dot trong nap xi
lanh bang each phay mat dau nap xi lanh mpt
lop kim loai voi chieu day la 0,5 mm
- Giam chieu cao buong dot trong xi lanh
bang each phay mat dau xi lanh mgt lap kim
loai voi chieu day la 1,0 mm
3.1.4 Cdi tien he thdng cung cdp nhien lieu
cho dgng ca
He thong nhien lieu lam nhiem vu cung cap
hon hop chay (gom hon hgp xang va khong khi
sach) dong deu ve so lugng va co thanh phan
phii hop voi cac che dp lam viec cua dpng co,
dam bao dot chay hoan toan nham phat huy
cong suat cao nhat, tiet kiem nhien lieu va han
che 6 nhiem moi truong sinh thai
Hien nay, he thong cung cap nhien lieu
dgng CO xang tren xe may dupe su dung gom hai loai: He th6ng cung cAp nhien lieu dung bp che hoa khi va he thfing cung cap nhien lieu phun xang dien hr
Dgng CO Wave Anpha 110 cc sir dung trgn
xe All Star 2017 - VNUF la loai dimg bp che hoa khi nen thanh tich ciia xe trong cugc thi
"Lai xe sinh thdi tiet kiem nhien lieu" nam
2017 chua cao
Sau khi tim hieu ve uu, nhugc diem cua he thSng cung cap nhien lieu dung bp che hoa khi
va he thong cung cap nhien lieu phun xang dien tii, vai muc tieu la nang cao hieu suat tieu hao nhien lieu cho xe phuc vu thi dau nham nang cao thanh tich, chiing toi de xuat nghien cuu thay the he thong cung cap nhi^n lieu diing
bp che hoa khi bang he thong phun xang dien
hi Tuy nhien, theo quy dinh cua cugc thi, nSu cac dgi su dung he thong phun xang dien tii cho dgng co Wave Anpha 11 Occ thi bit buoc phai sir dung bom mang do Ban to chitc cugc thi cung cap Do vay, can thiet phai nghien cihi xay dyng so do he thong phun xang dien tu cho dgng co sir dyng bom mang do Honda
cung cap, ket qua the hien o hinh 1 va so dh
dau noi cac phan tir trong he thong cung cap nhien lieu phun xang dien hi a hinh 2
Hinh I Sff do he thong phun xang di£n tu sd dung bom mang do Honda cung cap / Binh chua khi nen; 2 Van cdp khi; 3 Van dieu dp; 4 Van dieu chinh dp sudt;
5 Bam mdng; 6 Van mot chieu; 7 Binh xang (BTC cdp); 8 Voi phun xang; 9 Dong ca
Trang 4• ^ r
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Hinh 2 So' do dau n6i cac phan tu* trong he thong phun xang diln tu' sir dyng bom mang
3.2 Nghien ciru cai tien he thong truyen lyc
3.2.1 Thiet ke ly hap mot chieu truyen md
men xoan td tr^fc dia xich bi dgng den moay
ffbdnhxe
Muc dich cua viec che tao xe phyc vu cugc
thi "Lai xe sinh thdi tiet kiem nhien lieu" vai
khau hieu la: "/ lit xang xe di duac bao nhieu
ki Id met" Nhu vay giam tieu hao nhien lieu
nham nang cao thanh tich dat dugc thi can thiet
phai nhien cim tim giai phap giam mat mat do
ma sat trong he thong truyen lyc xuong nho
nhat CO the Tuy nhien, hien trang ciia he thong
truyen luc toi banh xe All Star 2017 - Vnuf la
dimg khap mgt chieu giira dia xich bi dpng voi
moay o banh xe la dung lip xe dap nen gay ra
mat mat do ma sat con lan Khi xe dang
chuyen dpng, neu ta tat dpng co (ngat mo men
chii dpng), vanh lip khong quay theo quan tinh
banh xe, cot lip ciing ca lip quay theo chieu
kim dong ho, khi quay ca lip trugt tren rang trong ciia vanh lip, ep 16 xo xuong gay hao ton
ma sat dang ke De khac phyc hien tupng nay, nhom nghien ciiu de xuat cai tien he thong truyen luc xe All Star 2017 bang each thay the
bp khap mgt chieu diing lip xe dap bang ly hgp
ty dgng van rang mgt chieu Ly hgp ty dgng dong mo phu thupc vao lyc tren nhanh xich chil dpng cua truyen dpng xich, nghia la khi khong truyen mo men xoan cho banh chii dpng (tat may) thi ly hgp tu dpng tach truyen dpng lam cho banh xe quay tron tren true nen giam dupe ma sat trong qua trinh chuyen dpng
Bg ly hpp dupe thiet ke theo nguyen ly chep hinh tir bg ly hgp mpt chieu cua he thong khoi dpng bang chan dgng co xe may (kich thuac va dang rang khong doi, chieu nghieng ciia rang
ly hpp va true xoan dupe thiet ke theo huong ngupc lai) nhu a hinh 3
Hinh 3 Ly hop ty d^ng mot chi^u lap tren banh sau ciia xe tiet kiem
TAP CHI KHOA H O C VA CONG N G H E LAM N G H I E P SO 2 - 2019 115
Trang 5Trong do: Vtp - the tich toan phan; Vc - the
tich buong dot; VK, - the tich lam viec
Tir cong thiic (2) ta thay: Muon tang ty so
nen B ta co the tang the tich lam viec cua xi
lanh hoac giam the tich buong dot trong xi
lanh Tuy nhien ta khong the tang the tich lam
viec cua xi lanh do kich thuac tay bien, tay
quay true khuyu dgng ca la khong the thay doi
Vi vay ta chi co the tac dpng bien phap ky thuat
de giam the tich buong dot trong xi lanh cua
dgng CO (giam Vc) bang nhirng giai phap sau:
- Giam chieu cao buong dot trong nap xi
lanh bang each phay mat dau nap xi lanh mpt
lop kim loai voi chieu day la 0,5 mm
- Giam chieu cao buong dot trong xi lanh
bang each phay mat dau xi lanh mpt lop kim
loai voi chieu day la 1,0 mm
3.1.4 Cdi tien he thdng cung cdp nhien lieu
cho dgng cff
He thong nhien lieu lam nhiem vu cung cap
hon hop chay (gom hon hgp xang va khong khi
sach) dong deu ve so lugng va co thanh phan
phii hgp vai cac che do lam viec cua dpng co,
dam bao dot chay hoan toan nham phat huy
cong suat cao nhat, tiet kiem nhien lieu va han
che 6 nhiem moi truong sinh thai
Hien nay, he thong cung ckp nhien lieu
dgng CO xang tren xe may dugc sir dyng gom hai loai: He thong cung cap nhien lieu diing bg che hoa khi va he th6ng cung cap nhien heu phun xang dien tu
Dgng CO Wave Anpha 110 cc su dung tren
xe All Star 2017 - VNUF la loai diing bg chg hoa khi nen thanh tich cua xe trong cupc thi
"Lai xe sinh thdi tiet kiem nhien lieu" nam
2017 chua cao
Sau khi tim hieu ve uu, nhugc diem cua he thong cung cap nhien lieu dimg bg ch^ hoa khi
va he thong cung cap nhien lieu phun xang dien tir, voi myc tieu la nang cao hieu suat tieu hao nhien lieu cho xe phyc vu thi dau nhSm nang cao thanh tich, chiing toi de xuat nghien ciiu thay the he thong cung cap nhien lieu dung
bg che hoa khi bang he thong phun xang dien
hi Tuy nhien, theo quy dinh ciia cupc thi, neu cac dpi sir dung he thdng phun xang dien hi cho dpng CO Wave Anpha 11 Occ thi bat bugc phai su dyng bom mang do Ban to chirc cugc thi cung cap Do vay, can thiet phai nghien ciiu xay dung so do he thong phun xang dien tu cho dpng CO sii dyng bom mang do Honda cung cap, ket qua the hien o hinh 1 va so do dau noi cac phan tit trong he th6ng cung cSp nhien Heu phun xang dien hi 6 hinh 2
Hinh 1 Sff do he thong phun xang dign tir su dung bom mang do Honda cung cap
L Binh chua khi nen, 2 Van cdp khi; 3 Van diiu dp; 4 Van dieu chinh dp sudt,
5 Bam mdng; 6 Van mgt chieu; 7 Binh xang (BTC cdp); 8 Voi phun xang; 9 Dong ca
Trang 6VuSUsdiakip
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Hinh 2 Sff do d^u n6i c^c phan tu trong hf thSng phun xang dien tu su dung bffm mang
3.2 Nghien ciru cai tien he th6ng truyen lyc
3.2.1 Thiet k& ly hgp mgt chieu truyen md
men xoan tir tr^c dia xich bi dgng den moay
ffbanh xe
Myc dich ciia viec che tao xe phuc vu cupc
thi "Lai xe sinh thdi tiet kiem nhien lieu" voi
khau hieu la: "1 lit xang xe di duac bao nhieu
ki 16 met" Nhu vay giam tieu hao nhien lieu
nham nang cao thanh tich dat dupe thi can thiet
phai nhien ciiu tim giai phap giam mat mat do
ma sat trong he thong truyen lyc xuong nho
nhat CO the Tuy nhien, hien trang ciia he thong
truyen lyc tai banh xe All Star 2017 - Vnuf la
dimg khap mpt chieu giira dia xich bi dpng voi
moay o banh xe la diing lip xe dap nen gay ra
mat mat do ma sat con Ion Khi xe dang
chuyen dgng, neu ta tat dpng ca (ngat mo men
chii dpng), vanh lip khong quay theo quan tinh
banh xe, cot lip ciing ca lip quay theo chieu
kim dong ho, khi quay ca lip trugt tren rang trong cua vanh lip, ep 16 xo xuong gay hao ton
ma sat dang ke De khac phuc hien tupng nay, nhom nghien ciiu de xuat cai tien he thong truyen luc xe All Star 2017 bang each thay thg
bg khop mpt chieu dung lip xe dap bang ly hpp
tu dpng vau rang mpt chieu Ly hpp tu dgng dong mo phy thugc vao luc tren nhanh xich chu dgng ciia truyen dgng xich, nghTa la khi khong truyen mo men xoan cho banh chii dgng (tat may) thi ly hpp tu dpng tach truyen dpng lam cho banh xe quay tron tren true nen giam dugc ma sat trong qua trinh chuyen dgng
Bp ly hpp dupe thiet ke theo nguyen ly chep hinh tir bg ly hgp mgt chieu cua he thong khoi dgng bang chan dgng co xe may (kich thuac va dang rang khong doi, chieu nghieng cua rang
ly hpp va true xoan dugc thiet ke theo huong ngupc lai) nhu a hinh 3
Hinh 3 Ly hop ty dong mfit chigu \ip tren banh sau eiia xe tiet kiem
Trang 73,2.2 Ndng cao hieu sudt chung he thong
truyen lire
Hieu suat chung ciia he thong truyen lyc ciia
xe dugc xac dinh theo cong thiic:
'7,
Trong
_ W, _
~ AT, ~
do: Ni - cong
= 1 suat
N,
(3) hieu dung truyen den banh xe chu dpng;
N, - cong suat mat mat do ma sat va
khuay dau;
Ne - cong suat chi thi cua dpng co
Tir cong thiic (3) cho thay, voi cong suat chi
thi ciia dpng co khong doi (N^ = const), d&
nang cao hieu suat chung cua he thong truyen
lyc bang cac giai phap nham giam toi da cong
suat mat mat do ma sat va do khuay dau
De giam cong suat mat do do ma sat va
khuay dau bang each nghien ciiu loai bo hop so
ra khoi dpng co dong thoi thiet ke he thong boi
tron tryc tiep cho cac chi tiet trong dgng ca co
chuyen dpng tuong doi vai nhau theo phuang
phap boi tron Hon hpp
3.2.3 Xdc dinh ty so truyen hop ly td tr^c
khuyu dgng cff den true bdnh xe chu dgng
Ty so truyen hgp ly ciia he thong truyen lyc
con bi gioi han bai dieu kien keo va bam de
cho xe c6 the chuyen dpng dupe tren duong
Mo men dinh miic (Mj^) cua dgng co dupe
xac dinh (Nguyin Hiru Can, 2007) nhu sau:
M 8,44
^i., = —^ = -— = 7,03 (Nm) (4)
"" k 1,2 ^ -^ ^ '
Trong do:
- k - he so thich img cua dpng co, voi dgng
CO xang thi k = 1,1 ^ 1,35, ta chpn k = 1,2
- Mo men xoan 6 banh xe chu dpng dugc tinh theo cong thiic:
^b.=^dn,-Kl.-n, (5)
Trong do:
Til - hieu suat ciia he thong truyen lyc, so bg
chpn T|t = 0,88 (Nguyen Hiiu CSn, 2007);
ich - ty so tmyen chung ciia he thong tmyen lyc
Thay gia tri ciia Mdm = 7,03 (Nm) vao cong thuc (5) ta tinh dugc Mbx nhu sau:
M^^ =7,03.j;;,.0,88 = 6,18.i;,,, (Nm) Khi do ta tinh dugc lyc leo tiep tuyen 6 banh xe chii dgng theo cong thirc sau (Nguyen Him cdn, 2007):
^ = ^ = ^ = 19,04 (N) (6) r^^ 0,325
Voi ban kinh cua banh xe la: rbx = 0,325 (m)
Dieu kien de xe chuyen dpng dupe hen duong phai tuan theo bat dang thirc sau:
P ^ > F K > S P C (7)
Trong do:
Pip - luc bam a banh xe chii dgng;
SPc tong luc can tac dung len xe khi chuyen dgng
- Xdc dinh tong luc cdn tdc dtiug ten xe khi chuyen dong
So do lyc tac dyng len xe khi chuyen dpng tren duong nam ngang the hien 6 hinh 4 Cac lyc can chuyen dpng bao gom: lyc can lan; luc can quan tinh; luc can khong khi
Hinh 4 Luc va mo men tac dung len xe chuyen dong khi tang tdc
Trang 8Sir dung ly thuyet 6 to may keo (NguySn
Him Can, 2007) da tinh toan dugc gia tri cac
lyc can chuyen dpng cho xe, kgt qua thu dugc
nhu sau:
+ Luc cdn lan:
Pf = P^, + P^, -Z,.f+Z^.f^ = f.G = 0,03.900-27
(N) (8)
+ Luc cdn khong khi:
Vi xe chuyen dpng voi t6c dp kha cham, tigt
dien chan gio nho nen lyc can khong khi la
khong dang ke co the bo qua
P.,=C,,F,Vl^a (N) (9)
+ Ltfc cdn qudn tinh:
Mgt each gan diing, khi bo qua quan tinh
ciia cac chi tiet chuyen dong quay ta co:
C ^ ^ 900 ^ 1 3 ^ ^
' g 9,81 30 \ > \ !
Nhu da trinh bay 6 trgn, do biSn thign van
cua xe kha Ion (van toe Ion nhdt ciia xe:
Vniax = 13,89 m/s), thai gian tang ga tinh tir
luc bat dau khoi hanh (van toe ban dau bang
kh6ng) de dat dugc van toe Ion nhat la 30
(giay)
- Luc bam duac xdc dinh nhu sau:
Pb= (p.Gb (N) (11)
Trong do:
<p - la he so bam, voi mat duong nhua thi ta
CO he so bam (p = 0,35;
Gb - Trgng lugng bam, trpng lugng o banh
xe chti dgng, Gb= 540 (N)
Thay gia tri cua (p, Gb vao cong thirc (11) ta
dupc:Pb= 0,35.540=189 (N) (12)
Thay gia tri Pf (cong thiic 8), Pj {cong thiic
10), gia tri Ft tir cong thiic (6) va gia tri Fb tir
cong thiic (12) vao bat dang thiic (7) ta dugc:
27+42,47<l9,03.ich<l89^3,65<ich<9,93(13)
Ty so truygn ctia he thong truyen lyc thoa
man dieu kien keo va bam phai tuan theo bat
dang thiic 13 Can cii vao tai lieu huong dan
thiet ke chi tiet may ta chgn he thong truygn luc bao gom he thong hniyen dgng xich hai cap voi cac dia xich co so rang hrong ung la Z | , Z:, Z3 va Z4, tir do tinh duoc ty so truyen chung thoa man dieu kien keo va bam nhu sau:
(14)
Z, Z, 36 48 _
I, =i,.i-.=^.—^ = — — = 8,82
Z, Z^ 14 14
Zi, Z3 - so rang dia xich chii dgng so 1 va 3;
Z2, Z4 - so rang dia xich bi dpng so 2 va 4
- Kiem tra toe do cua xe theo quy dinh cugc thi:
Voi ich ^ 8,82 thi van toe chuyen dpng tinh tign cua xe duoc tinh toan nhu sau:
60.1000./,;, 60.1000.8,82 (m/s) (15) Nhu vay, voi (ich = 8,82) duoc tinh chpn o
tren da thoa man digu kien keo bam cho xe chuygn dpng trgn du6ng, dong thai dap ling
toe dp toi thieu (V^e > 25 km/h) theo quy dinh
3.3 Nghign ciru hinh dang khi dong hoc cua xe
3.3.1 Xdc dinh gdc nghieng mat mui xe phia trudc
Lyc can khong khi anh huong lan den chi phi nhign lieu khi xe chuygn dpng tren quang duotig c6 chieu dai nhat dinh, lyc can cang nho thi lupng tieu hao nhign lieu cua xe cang giam
Luc can khong khi ciia xe phu thupc vao goc nghieng cua mui xe phia truoc Gia tri cac g6c nghieng mat mui xe va mat kinh chin gio phia truoc ciia xe dupe xac dinh bang each kg thira cac ket qua nghign ciru tir tai lieu cua Julian Happian-Smith (2002), do la: Quan he giiia he
so dang khi dgng hgc voi goc nghieng mat mui
xe phia truoc ( a ) (hinh 5) Goc nghieng mat mui xe phia truo'c dugc xac dinh bang each chgn he so dang khi dgng 6 gia tri thap nhat co the, ta chpn Cd ^ 0,35, sau do dya vao do thj tren hinh 5 ta xac dinh dupe gia tri tuong iing goc nghigng mat mui xe phia truoc la cr = 30"
TAP C H I KHOA H O C VA CONG N G H E L A M N G H I E P SO 2 - 2019
Trang 93.3.2 Xdc dinh gdc ndng dudixe
Goc nang duoi xe (y) cua xe ciing anh huong
hijc tiep va dang kg den luc can khi dgng De
xac dinh gia tri goc nang sao cho luc can khi
dpng nho b5ng each ke thira ket qua nghien cim
hi tai lieu (William F MiHiken, 1995), do la d6
Cd
thi quan he giiia he s6 dang khi dpng voi goc nang khung duoi xe (hmh 6) Tir he s6 dang khi
dpng nho nhat da chpn (Cj = 0,35), dya vao dd
thi hinh 6 ta xac dinh duoc gia tri cua goc nang
cua khung duoi xe tuong img la y = 15"
Hinh 5 Do thi quan he giua h^ $6 dang khi dong
hoc voi goc nghieng chan gio phia triro^c
Hinh 6 Dd thi quan he giiia hS s6 dang khi d^ng vol goc nang khung duoi xe Can cir vao kgt qua tinh toan cac kich thuoc
hinh hpc, cac g6c nghigng ciia mat chan gi6
phia truac, goc nang 6 duoi khung xe, tren co
so tham khao cac mau xe trong thye te, kich thuoc so bg va hinh dang khi dgng hpc ciia xe thiet ke dupe the hien tren hinh 7
Hinh 7 Kich thudc, hinh dang xe All Star 2017
4 K E T LUAN
Bang phuong phap nghien cuu ly thuygt va
ke thira tai lieu, ket qua nghien cim da nghien
ciiu giai phap hoan thien xe tiet kiem nhien
lieu theo hucmg nang cao hieu suat tieu hao
nhien lieu nham dat thanh tich cao trong cugc
thi "Lai xe sinh thai, tiet kiem nhign lieu" do
Honda to chiic, ket qua cy the la:
- Co so khoa hpc ciia giai phap han che
truygn nhiet ra moi truang xung quanh de tao dieu kien thuan lpi cho viec hinh thanh hon hgp chay cung cap cho dpng co
- Co so khoa hpc cua giai phap dot chay hoan toan hon hpp chay
- Co so khoa hgc cua nang cao ap suat cuoi thai ky nen
- Cai tign he thong cung cap nhign lieu cho dgng CO
Trang 10Thigt ke ly hgp tu dgng mgt chigu dg
tmyen mo men xoan tir tryc dia xich bi dgng
den moay banh xe, cat bo hop so nham nang
cao hieu suat chung he thong truyen lyc
- Xac dinh ty so truyen hpp ly hi hnc khuyu
dgng CO den true banh xe chu dpng, ic ^ 8,82
- Cai tien hinh dang khi dpng hgc cua xe,
xac dinh dupe g6c nghieng mat mui xe phia
truoc la a = 30^ va g6c nang cua khung duoi
xe tuong ling la y = 15"
TAI LIEU THAM KHAO
1 Nguygn Hiiu Cin, Da Qu6c Thinh, Pham Minh Thai (2007) Ly thuyet d to mdy keo Nha xuk ban Khoa
hoc va Ky thuat Ha Npi
2 Nguyin Diic Phu, TrSn Van T5, Nguyen Tit Tian
(1979) Ket cdu vd tinh todn ddng ca dot trong Nha
xudt ban Dai hgc va Trung hoc chuyen nghi?p Ha Noi
3 Julian Happian-Smith (2002) An introduction lo Modem Vehicle Design Printed and bound in Great Bntain
4 William F.Milliken and Douglas LMilhken (1995)
Race car Vehicle Dynamics SAE publication group
STUDY THE SOLUTION T O C O M P L E T E THE ALL STAR 2017 - VNUF
M O T O C Y C L E IN THE DIRECTION O F IMPROVING FULE
CONSUMPTION PERFORMANCE
Dang Thi Ha, Le Van Thai
Vietnam National University of Forestry
S U M M A R Y
Basing on theoretical method, the paper presents the scientific basis of making solutions to improve Wave Anpha 11 Occ motorcycle engine in the direction of improving fuel consumption performance Calculating and selecting the transmission system with a reasonable transmission ratio, satisfying the requirements of drag and adhesive conditions when moving while ensuring the speed of the competition as prescribed Automatic one-way coupling design for transmission to active wheels, thereby improving the performance of the transmission system Design the aerodynamic shape of the motorcycle so that the air resistance acting on the motorcycle is minimal to reduce fuel consumption when the motorcycle moves on the road with a certain length The research results are made the basis to improve fuel consumption performance for All Star 2017- Vnuf motorcycle and enhance achievements of motorcycle to take part in "eco-Mileage Challenge" competition annua! organized by Honda in Vietnam
Keywords: All Star 2017, automatic one - way coupling, eco-Mileage Challenge, fuel consumption performance, transmission system
Ngay nhan bai : 23/01/2019
Ngay phan bien : 11/3/2019
Ngay quy^t djnh dang : 18/3/2019
TAP CHI KHOA HOC VA C 6 N G NGHE LAM NGHIEP SO 2 - 2019