1

Hi C hc Vit Nam thi OLYMPIC C HC TON QUC

Mn thi: NG DNG TIN HC TRONG C HC (CHI TIT MY)

Ngy thi: 14 thng 04 nm 2013

Thi gian: 240 pht.

H thng dn ng xch ti gia cc tng ta nh (hnh 1) vi:

Hnh 1

1. ng c; 2. Ni trc vng n hi; 3. Hp gim tc hai cp ng trc; 4.B truyn xch nghing vi

phng ngang mt gc = 450; 5. Xch ti; 6.B phn cng xch ti

Cc yu cu k thut cho trc: Lc ko xch ti F = 8000N, vn tc xch ti v = 0,24 m/s. bc xch ti pc

= 40mm, s rng a xch ti z = 9, gc nghing b truyn xch nghing vi phng ngang = 450. T s

truyn hp gim tc ng trc u = 16, thi gian lm vic L = 6 nm, ti trng tnh, 1 nm lm vic 300 ngy,

mi ngy lm vic 12 gi. S vng quay ng b ng c 1500vg/ph.

Phn 1 Phn tnh ton chi tit my (20)

1.1 Tnh cng sut cn thit, chn t s truyn b truyn xch, chn ng c v lp bng cc thng s

k thut

1.2 Thit k cc b truyn bnh rng trong hp gim tc ng trc

Yu cu: Tnh trn phn mm Autodesk Inventor theo tiu chun ISO 6336:1996, chn vt liu (theo

tiu chun ISO: thp 17CrMoV5 11 thng ho vi gii hn mi tip xc sHlim 520MPa, h s an

ton SH=1,2, SF=1,3), xc nh thi gian lm vic Lh, gc nghing rng, khong cch trc, mun

rng, s rng, ng knh vng chia, chiu rng vnh rng, dch chnh rng, vn tc vng ca bnh

rng, lc hng tm, lc vng, lc dc trc... M hnh 3D cc cp bnh rng.

Lu : Chn cc h s ph hp tnh ton trn phn mm Autodesk Inventor.

Cc kt qu a vo thuyt minh.

1.3 Thit k b truyn xch Chn trc: S dy xch, s rng z1 v z2. Yu cu: Chn xch theo tiu chun ISO 606:2004 (EU), nhp s rng z1, z2, cng sut P, s vng

quay n.

2

Tnh bng Autodesk Inventor: Bc xch, s mt xch, chiu di xch, khong cch trc, ng knh

cc a xch, vn tc trung bnh, lc trn nhnh cng F1 v chng F2, lc tc dng ln trc. M hnh

3D b truyn xch.

Cc kt qu a vo thuyt minh.

1.4 Thit k cc trc hp gim tc ng trc v chn then

+ Tnh bng tay: Xc nh ng knh s b, phc tho s b kt cu trc vi [] = 30 MPa.

+ Tnh bng Autodesk Inventor: V s phn tch lc tc dng ln cc bnh rng, a xch, ni

trc. nh kch thc cc on trc, chn vt liu thp vi Sy = 400MPa, nhp gi tr cc lc tc dng

ln trc, cc biu mmen un, ng sut. M hnh 3D cc on trc.

+ Chn then theo phn mm.

a cc kt qu vo thuyt minh.

1.5 Chn ln

+ Chn ln cho cc trc hp gim tc trong Autodesk Inventor theo tiu chun.

a cc kt qu vo thuyt minh.

Phn 2 Phn m hnh ho chi tit my v cm chi tit my (8)

- Hon thin m hnh kt cu cc chi tit v lp cm chi tit lp trn trc hp gim tc, bao gm a

xch, cc bnh rng, na ni trc, cc ln

- Th hin bn v 2D kt cu trc trung gian vi y kch thc lp, dung sai.

a cc kt qu vo thuyt minh.

Phn 3 Phn phn tch chi tit my v la chn s ng (12)

3.1 Nu thay th cc bnh rng tr rng nghing bng cc cp bnh rng tr rng thng th kch thc cc b

truyn thay i nh th no. Minh chng bng kt qu tnh ton trn phn mm Autodesk Inventor vi cc gi

tr gc nghing trong khong gi tr 200 8

0.

3.2 V cc phng n s ng cho h thng truyn ng (trn Autodesk Inventor) vi b phn cng tc l

xch ti nh hnh 1. Cc yu cu k thut cho trc ca b phn cng tc nh Phn 1.

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Lu :

- Bi lm trnh by dng file word bao gm tt c ni dung yu cu trn v lu thnh file c

Olympic_Chitietmay_Sobaodanh.doc v lu di dng .doc v .pdf file. Cc file kt qu tnh lu di dng

PDF file.

- Lu tt c file kt qu tnh v thuyt minh vo 1 th mc

- Lu cc file m hnh chi tit, m hnh lp, bn v vo cng 1 th mc.