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IVGHIEIM CIJU T H I E T K E , CHE T A O H E THOIVG T H I E T Bf K H A O IMGHIEIVI BAIMH X E CO iVIAU TREIXI IXIEIM D A T Y E U
THEO PHUOIMG P H A P C A T D A T X I C L O I T
T r i l u Anh Tudn', Phan Thanh Tinh^
' T6MTAT
Qua trinh tuong tac cua banh xe c6 mau tren nen dat yeu xay ra rat phirc tap, vi the viec nghien cuu thuc nghiem de xac djnh kha nang keo bam ciia banh xe va kiem chimg cac mo hmh ly thuyet la rat can thiet.
Cac he thong thiet bi khao nghiem banh xe va may keo a nuoc ta hien nay chi xac dinh duoc cac gia tri trung binh cua cac thanh phan phan luc tac dung len mau bam. Bai viet nay gioi thieu ket qua nghien cuu thiet ke, che tao va kha nang iing dung mot he thong thiet bi thi nghiem banh xe co mau bdng phuang phap cdt dat xicloit tren kenh dat nhan tao. He thong thiet bi co the do dupc cac gia tri tuc thoi cua cac thanh phan lire tac dung len mau bam, tu ghi lai cac ket qua tren may hnh de phuc vu cac nghien cim tiep theo nhu nghien cuu tinh chat keo bam, tinh chait dong luc hoc,.. .cua cac may keo khi lam vide tren nen dat yeu.
Tu khda.' May keo, khao nghiem may keo, banh xe may keo, phuong phap cit dait
I. DAT VAN DE
Qua trinh tuong tac giua banh xe vdi dat la mdt qua trinh dien ra rat phirc tap, dac biet la khi cac banh xe cd mau bam lam viec tren nen dat yeu - loai ndn dat phd bidn trdn cac mong trdng lua nudc d nudc ta. Cac thanh phan phan luc tac dung len banh xe cd mau bam thay ddi lien tuc, cd tinh chat chu ky.
Viec xac dinh dupc gia tri tire thoi va qui ludt thay ddi ciia cac thanh phan luc tac dung len cac mau bam ddi hdi phai sir dung cac phuang phap do hien dai. Van de nay da dupc giai quyet tdt d cac nudc phat trien, song d nudc ta chua dupc quan tam dung mirc.
Qui dao chuyen ddng cua mau bam bdnh xe tuan theo qui ludt xicloit. Do dd md hinh thi nghidm banh xe cd mau bdng phuong phap cdt dat xicloit se thda man cao cac ydu cau nghidn cim banh xe tren nen dat yeu.
Dudi day xin gioi thieu mdt sd k i t qua nghidn cim thiet ke, che tao mdt he thdng thiet bi do cdc thanh phan phan luc tdc dung Idn mau bam theo phuang phap cdt dat xicloit trdn ranh ddt nhdn tao, nhdm gdp phan phat triln he thdng thiit bi nghiin cim thuc nghiem cac tinh chat keo bam cua banh xe, gdp phan hoan thien co sd thiet ke, che tao cac banh xe may keo khi lam viec t r i n ndn dat y i u d Viet Nam.
' Trudng D^i hpc Su ph^im Ky thu^t Hung Yen
" Vi^n Ca di|n Nong nghi?p va CNSTH
L NOI DUNG VA PHUONG PHAP NGHIEN CUU 1. Phuong phdp cdt ddt xicloit
Khi banh xe chuyen ddng, dudi tac ddng cua mau bam lam cho cac phan tir dat bi bien dang va xuat hien cac phan lire tdc dpng len mau. Phuang, chidu va do Idn ciia cac thanh phan phan luc phu thudc vao phuang tac ddng cua mdu bdm vd mirc dp bien dang cua dat.
Phuang phap cdt dat xicloit la sir dung thiit hi tao ra su chuyin ddng cua cdc tam cdt (mdu bdm) theo qui ludt xicloit, tuong tu n h u sir tac ddng ciia cdc mau bdm bdnh xe vdo n i n dat. Trdn c a sd dd do cdc thdng sd ddng hgc vd cdc thdnh phan phan lire tdc dung Idn mdu bdm.
Trdn hinh 1 Id so dd ddng luc hgc ciia bdnh xe cd mau khi chuyen ddng trdn dat yeu (cac mau bdm ngap sdu trong dat).
Phuang trinh c h u y i n ddng ciia dinh mdu bdm:
{x= Rj.[(\-5)(p + co?.(p]
l > ' = ' / ^ / l - s i n ^ ) (1) Trong dd: 8 Id dp tmpt cua bdnh xe dupc tinh ) cdng thirc:
theo cdng thirc . ^ = 1 - ^ = 1.
R,oj (2)
V„ - van tdc ly tiiuylt, tinh tiieo vdng trdn dinh mau V,t = Rjio.
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•^ = VM
Hinh 1. So dd ddng luc hpc bdnh xe Phuang trinh chuyen ddng ciia diem M bat ky
\ ' ^
; \
> ^ " ' ' ' '
- - ^ ^
•mdy/////.
M F,
trdn mau bam:
(3) Van tdc tuyet ddi cua diem M trdn mau Id V^, dupc tdng hpp tir van tdc quay tuong ddi V^ vd van tdc tinh tien V:
qM I
+ F
cd mdu khi chuyin ddng trdn nin ddt
- Do cac gid tri tire thdi cua gdc quay banh xe {p(t) - Do cdc gid tri tuc thdi cua cac thanh phan phan lire F,(t)vaF„(t).
- Sir dung cdng thirc (4) de tinh luc keo Fx(t) va lire ndngFy(t).
2. Thiit kl, chi tao h | tiidng tiiilt bj tiii nghi|m Theo cdc nguydn ly trdn, da thiet kl, chi tao dupc mpt he thdng thiet bi khao nghiem bdnh xe, so dd tdng thi cua he thdng thi hien tren hinh 2.
Phdn tich V^ thdnh 2 thanh phan: van tdc tiep tuyIn vdi mau bdm N^ vd van tdc phdp tuyen la V„.
M i n
Theo phuong tiip tuyIn vdi mau bdm xuat hien phan lire tiip tuyIn (lire ma sdt) F, cd chieu ngupc vdi V„ cdn tiieo phuang phap tiiyen xuat hien phan lire F„. Phan lire tdng hpp F ciing phuong vd ngupc chieu vdi vdc to van tdc V^-
Phdn tich phan luc F tiidnh 2 tiidnh phan: Thdnh phan F^ song song vdi mdt dudng. cd tdc dung day banh xe chuyen ddng va do dd cdn gpi Id luc keo;
tiidnh phan Fj, vudng gdc vdi mdt ddng vd cdn dupc gpi Id luc ndng bdnh xe. Gid tri cua lire kdo vd lire nang cd till xdc dinh theo cdng thirc:
F^ = F„ sm((p -P)-F, cos(^ - (3) F^ = F„ cos((p -P) + F, sm(cp - P)
Tir cdc quan h | trin, cd till xdc dinh cdc tiidnh phan phan lire tdc ddng Iln mau bdm theo nguyen ly chung sau day:
- Trong mdi tiii nghiim, cd dinh do tiirpt vd van tdc chuyen dpng: 5= const, V= const
(4)
Hinh 2. So dd tdng till h i tiidng tiiilt bj tiii nghi|m su tuong tdc cua mdu bdm vdi ddt
1- Khung di ddng; 2- Trdng tdi; 3 - Ddy cap tdi; 4- Banh xe dd khung; 5- Dudng ray; 6- Banh xe chii ddng ; 7- Mau bam ; 8- Bd phdn Idp cam bien luc;
9-Kdnh dat thi nghiem; 10- Cdp tmyin thdng tin;
11- Bd phdn thu thap thdng tin; 12- May tinh.
Khung 1 cd chirc ndng tuong tu nhu khung mdy keo. Khung dupc chuyin ddng tjnh tiln trin 2 dudng ray 5 vdi van tdc V khdng ddi trong qud trinh thi nghiim. Trdng tdi 2 dupc quay vdi van tdc co, nhd
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 5/2011
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mpt ddng ca dien (khdng the hien trdn hinh) va thdng qua day cap 3 se lam cho khung chuyen dpng tinh tien. Banh chii dgng (banh xe thi nghiem) 6 dugc chuyen dpng quay vdi van tdc o\ . Trdn bd phan l2p cam bien lire 8 dupc Idp mau bam thi nghiem 7 va 2 cam bien do luc. Tin hidu luc tren cam bien se dugc cap tmyen thdng tin 10 tmyen len bd phan thu thap thdng tin 11 va dua den may tinh 12 de ghi lai cac tin hieu do dudi dang tep dti lieu, rat thudn tien de chuyen vao cac phan mem xir ly sd Ueu thdng dung nhu Matib, Excel,...
Nen dat thi nghiem trong kenh dat 9 cd the dieu chinh dupc thanh phan, dp chat, dd am theo ydu cau va muc dich nghidn cim (tuong tu nhu nen rudng).
Cac thanh phan phan luc Ft(t) va Fn(t) dupc do bdng 2 cam bien Goad cell) MT1260 do Dire san xuat. So dd Idp cac cam bien lire trdn khung do lire the hien tren hinh 3.
Hinh 3. Khung do luc
1-Ma'u bam; 2- Load cell do lire tiep tuyen; 3 - Load cell do luc ning; 4- Khdp quay; 5- Thanh dim; 6- Tam da; 7- Dim bit load cell; 8- True banh chii xe chti ddng r n m Hi dong
Hinh 4. So dd tmyIn ddng cua ddn thi nghiim 1-Ddng ca hop sd giam td'c; 2-Xich tmyen ; 3-Trdng tai; 4- Binh ring trdng tai; 5-Banh ring trung gian; &
Binh ring tren true banh xe thi nghiem; 7-Banh xe;
8 Day cap ; 9 Banh xe; 10- Duong ray.
H | thdng thiit bi cho phep thay ddi dupc cac thdng sd sau:
- Thay ddi do trugt:
Dp trupt cua banh chii ddng cd the dupc xac dinh theo cdng thirc:
^, R.
R.
Trong dd: R, - ban kinh trdng tdi; R^ - ban kinh vdng trdn dinh ciia mau bam cua bdnh xe; ojt - tdc dd quay trdng tdi; cot tdc do quay banh xe; z,, Zj, - sd rang ciia banh rdng 4 va banh rdng 5 (hinh 4). Thay ddi z, va Zi, se thay ddi dupc dp trupt 5.
- Thay ddi van tdc tinh tien V:
Van tdc tiln V cda khung cd the dieu chinh dupc nhd thay ddi tdc dp quay cua ddng ca didn 1 (hinh 4).
- Thay ddi gdc nghieng miu bam p
Bd phan Idp mau bdm cho phep thay ddi dupc gdc nghieng ciia mau bam p so vdi phuong hudng kinh.
- Thay ddi do in siu cua miu bam h:
Dp dn sdu cua mau bam vdo ranh dat cd thi dilu chinh dugc nhd thay ddi cdc banh xe do 4 (hinh 1) vdi cdc dudng kinh khde nhau.
HL KET quA NGHEN CUU VA THAO LUAN
Dan thiit bi dd thir nghiem cho mdt loai mau bdm cd bl rdng b = 0,1 m, ban kinh vdng trong dinh Rj = 0,25 m ti-en rdnh dat nhdn tao cd dp chdt a^ = 46457 Pa Goal nen dat yiu) vdi cdc phuong an thi nghiim khde nhau bdng cdch tiiay ddi cdc thdng sd van tdc V, gdc nghidng mdu (3 vd dp tiupt 5 .Trdn hinh 5 Id mdt kit qua minh hga vdi V= 0,26 m/s, p=30°, 5= 10%.
Cdc kit qud trin phan dnh true quan qui ludt tiiay ddi cdc thdnh phan phan lire theo thdi gian vd tiieo gdc quay cua bdnh xe, giup cho ngudi nghiin cim dl nhan tiiay sir anh hudng cua cac tiidng sd kit cau, van tdc vd dp tmpt ciia bdnh xe din cdc thanh phan phan luc tdc dung Iln mau bam. Cac sd lieu tiii nghiim duoc ghi lai b-ong may tinh dudi dang file dir lieu, cd till dupc sir dung Idm co sd dir lilu cho cac nghidn cim tiep theo nhu kiim chimg md hinh Iy tiiuylt, nghiin ciru tiiilt k l banh xe cd mau,... Qua 180 phuong dn tiii nghiem cho tiiay h | tiidng thiet hi Idm vile rat dn dinh, cd dp tin cdy cao, ddp iing tdt cdc yiu cau nghiin cim.
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N G H £500 400
Z 300
£ 200
a
£ 100
0 -100
0.0 0 2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 tl8]
Hinh 5a. Sir phu thudc cdc thdnh phdn phan luc theo thdi gian
500 400
1
1
V
\ tf1 1
1
1
— Fx 1
' r 1
i
Fn Ft
j
—•-- F x
— 0 — Fy
^ . ^ F t
^ 300
£ 200
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g- 100
Ik
0 -100
0 20 40 60 80 100 120 140 160 phi [dp]
Hinh 5b. Su phu thudc cdc thdnh phdn phdn luc theo gdc quay bdnh xe
IV. KET LUAN
H I thdng thiit bi ddp img dupc cdc y i u cau sau:
- Do dupc lire k l o vd lire ndng cua mdu bdm theo ham thdi gian;
- Xdc dinh dupc dp trupt cua bdnh xe;
- Cd t h i thay ddi dupc mdt sd thdng sd ddu vdo:
gdc nghidng mdu bdm, van tdc chuyin ddng, do trupt, dp ngap sdu ciia mdu bdm vdo trong ddt, tinh chdt CO ly cua ddt;
- Cdc sd Ueu thi nghiem dupc ghi lai tren mdy tinh d dang file dir Ueu:
- He thdng tiiilt bi Idm vi|c dn dinh, dam bdo dp chinh xdc cao vd d l sir dung d l thuc h i | n cdc thi nghi|m.
TAI UEU THAM KHAC
1. Nguydn Xudn Ai, 1982. Nghien cuu mot sd thdng sdca ban ciia binh xe chu ddng may keo MTZ lim viec tien mdng lua nudc. Ludn dn Phd tiln si khoa hpc ky thudt. Vi|n Cdng cu vd Ca gidi hda ndng nghiip
2. BEKKER M. G., 1973. Ly tiiuyet h$ tiidng di't-may Tdi U|u djch tir tiing Anh sang tiing Nga.
Nxb Thiit k l c h i tao mdy, Matxeova.
3. T m n g tdm Gidm dinh may mdc tiiilt bi co didn ndng nghidp, 1997. He thdng cic tieu chuan khao nghiem, giim dinh cha't lugng may keo , may canh tac dimg trong sin xui't ndng lim nghiep (Tip I). Nxb Ndng nghiep.
4. Vultrev K., 1979. Nghien cuu thtrc nghiem d td, may keo. Nxb Ky thudt, Xd Phia.
RESEARCH, DESIGN AND MANUFACTURE AN EXPERIMENT EQUIPMENT SYSTEM OF WINDING WHEELS ON SOFT GROUND BY XICLOIT CUTFING SOIL METHOD
Trieu Anh Tuan, Phan Thanh Tmh Summary
Interactive process of winding wheel on soft ground occurs complexly so that the empirical research is necessary to determine the sticking and dragging of the wheels and to check the theoretical model. The assay equipment systems of wheel tractors in our country now only determine the average value of the force components acting on the winding sticks. This article presents an overview about the research, design, manufacture and the appbcability of experiment equipment systems of winding wheels by xicloit cutting soil method on the artificial land channel. The equipment system can determine the instantaneous value of force components acting on the winding sticks and record the results automatically on the computer for subsequent studies such as the study of the sticking and dragging criterion as well as dynamic nature of tractors when working on soft ground.
Key words.-Tracto/^, die experiment of ti^ctors, ti^ctor wheels, cutting soil method.
Ngudi phdn b i | n : PGS.TS. Ndng Vdn Vin
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