Performance Simulation on the Secondary Hydraulic Lifting System of the Excavator Bucket Fa-ye ZANG *, Zheng-hong CHEN and Xiang-zhen KONG

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1 016 Intrnational Confrn on Advand Manuftur Thnology and Industrial Appliation (AMTIA 016) ISBN: Prforman Simulation on th Sondary Hydrauli Lifting Systm of th Exavator Bukt Fa-y ZANG *, Zhng-hong CHEN and Xiang-zhn KONG Dpartmnt of Enginring Mhanial, Shandong Jiaotong Univrsity, Jinan *Corrsponding author Kywords: Exavator, Lifting systm, Fuzzy-nural ntwork ontrol, Prforman simulation. Abstrt. Th flow oupld sondary hydrauli lifting systm of th xavator bukt was prsntd, also its strutur and working prinipl. Th fuzzy-nural ntwork ontrol stratgy whih was ombination of fuzzy ontrol and nural ntwork has bn adoptd, and th math modl of th lifting systm is stablishd, thn th simulations of th prforman of th lifting systm has bn ondutd. Th flow oupld hydrauli systm with sondary rgulation an rgnrat gravitational nrgy of load. By ontrolling th hydrauli umulator, th pross ontrolling of th nrgy ryling and rusing has bn ralizd. Th systm prssur rang was xpandd, and th nrgy rusing fft and ffiiny wr improvd. Introdution At prsnt, th gravitation nrgy of th hydrauli lifting systm of th xavator bukt is not usually ryld and rusd whn its bukt and load was working undr lifting and falling down, whih auss th nrgy wast and th nvironmntal pollution. So a sondary hydrauli lifting systm of th xavator bukt was prsntd, in whih, th flow oupld sondary hydrauli transmission systm was usd to ryl and stor th gravitation nrgy of th xavator bukt whn its bukt and load was working undr lifting and falling down, and rusing th nrgy whn it was working, so th installation of th motor was indud to raliz nrgy saving and nvironmntal prottion. Th Strutur and Working Prinipl As shown in Figur 1, th systm was mad up of storag sondary omponnts, ontrol omponnts 1 for storag sondary omponnts, ltromagnti hang valv 3, balaning valv 6, load sondary omponnts 7, motor 8, ontrol omponnts 9 for load sondary omponnts and load ylindr 10, and so on. Th hydrauli storag omponnts 4 and prssur limiting storag omponnts 5 was onntd paralll with storag sondary omponnts, th high prssur oil of storag sondary omponnts was onntd with th main hydrauli systm of th xavator through ltromagnti hang valv 3, th shaft of th storag sondary omponnts and load sondary omponnts 7 wr onntd rigidly. Whn th bukt bgan to fall, th high prssur oil of storag sondary omponnts was swithd off onntion with th main hydrauli systm. Th load sondary omponnts 7 was adjustd to mak it work undr motor stat, and also th storag sondary omponnts work undr pump stat. Th lowr hambr oil of load ylindr 10 flowd to load sondary omponnts 7 rapidly in th influn of gravitation of bukt and gravity, th shaft of load sondary omponnts 7 rotatd to output torqu and spd, and thn driv th storag sondary omponnts working in pump stat to transport high prssur oil for th hydrauli storag omponnts 4 and prssur limiting storag omponnts 5. Th hydrauli storag omponnts 4 was rfuling in ordr from lowst to highst stting prssur, if th storag sondary omponnts no longr dlivrd high prssur oil or littl, th rfuling was nd, othrwis, th rfuling would b ontinud until rhing to th limitd prssur of prssur limiting storag omponnts 5. So by ontrolling th umulator, th nrgy ryling was ralizd, this would nsur highr oil prssur of th umulator, th rusabl fft was improvd.

2 Figur 1. Th systm strutur diagram. Whn th bukt bgan to lift, th high prssur oil of storag sondary omponnts was onntd with th main hydrauli systm. Th storag sondary omponnts was adjustd to mak it work undr motor stat, and also th load sondary omponnts 7 work undr pump stat. Th high prssur oil was dishargd from hydrauli storag omponnts 4 and prssur limiting storag omponnts 5 to driv storag sondary omponnts, it would rotat with th motor to driv th load sondary omponnts 7 jointly, and thn thy providd powr for load ylindr 10 to lift bukt and load. In working, on or mor hydrauli storag omponnts 4 and prssur limiting storag omponnts 5 ould b ontrolld in ordan with th wight of bukt and load, lift spd. Math Modl for th Flow Coupld Sondary Hydrauli Lifting Systm Th systm workd in load lifting and falling stat. Math Modl for Lifting Math Modl of th Eltro-Hydrauli Srvo Valv. Usually, th natural frquny of srvo valv is vry high, and th bandwih of th ontrolld hydrauli systm is lowr, so th ltro-hydrauli srvo valv an b td as a proportional omponnt, as following: Qsf ( s) K v I( s) hr, K is flow gain of th srvo valv((m 3 /s)/a), v Qsf (1) is output flow of th srvo valv(m 3 /s), I is input urrnt of th srvo valv (A). Math Modl of th Lifting Systm. 1) Th ontinuity quations of load sondary omponnts 7 and load ylindr n D 1 A dy V0 dp1 C p p1 () hr, D 1 is volum(m 3 /rad), n is motor spd (r/s), A is th piston fftiv ara(m ), y is piston displmnt(m), C p is total lakag offiint of load sondary omponnts 7, p 1 is th load ylindr prssur of rod hambr(pa), V 0 is th volum of rod hambr at mdian (m 3 ), is oil bulk modulus.

3 ) Balan quation of load ylindr and load d y dy A P1 m1 B m1 g f (3) hr, m 1 is th total mass of load, piston rod and piston omponnts(kg), y is th displmnt of piston rod(m), B is visous damping offiint, f is frition for of piston omponnts and ylindr ub, piston rod and orintation ovr and saling rings (N). 3) Input flow of storag sondary omponnts working in motor q q Vta dp Dn Cta p (4) hr, D is volum(m 3 /rad), C ta is total intrnal lakag offiint((m 3 s -1 )/Pa), p is prssur btwn umulator and sondary omponnts (Pa), V ta is th total volum from sondary omponnts to umulator(m 3 ). 4) Output torqu of storag sondary omponnts working in motor T p q hr, η is ffiiny of sondary omponnts. 5) Balan quation of umulator T (5) d q A BdVa pa p A m (6) A hr, p a is th working prssur of umulator(pa), A is th ross-stional aras of hambr (m ), m is oil mass of pips and umulator(kg), B is visous damping offiint, V a is volum of th umulator (m 3 ). 6) Input torqu of load sondary omponnts 7 working in pump T p T T (7) f hr, T f frition torqu(n m). Math Modl for Falling (1) Th motion quations of load ylindr 10 d y dy m1 g m1 B p1 A f (8) () Continuity quations of load sondary omponnts 7 working in motor dy V0 dp1 A D1n Ct p1 (9) (3) Output torqu of load sondary omponnts 7 working in motor p q 1 hr, η 1 is th total ffiiny of sondary omponnts 7. (4) Continuity quations of storag sondary omponnts working in pump ' 1 1 T p (10)

4 Vta dp D n q Cta p (11) (5) Balan quation of umulator d q A BdVa p pa A m (1) A (6) Input torqu of storag sondary omponnts working in pump T ' T T T (13) ' p m f Th ontinuity quation was th sam for th umulator working undr load lifting and falling. Prforman Simulation Main paramtrs of hydrauli xavator ar as blow: work quality is 7000 kg, bukt apity is 0.3m 3, powr is 48kW/300rpm, th arm lngth is 3500mm, th bukt rod lngth is 000mm, th working prssur is MPa. Th main paramtrs of th lifting systm ar as blow: th displmnt of load sondary lmnt 7 in th motor mod is 80mL/r, th nominal maximum displmnt of nrgy storag sondary omponnt in variabl pump mod is 100mL/r and umulator harging prssur and volum ar 1MPa and 16L.Control arithmti adopts th fuzzy nural ntwork ontrol. In ordr to gt mor rasonabl simulation load, and an rflt th working hartristis of hydrauli xavator, hoos th intrnational gnral of a typial yl: drop, mining to lifting th rotat 90 dgrs, and put th shovl, rotating bk. Th xavator is a typial yl is 0s [5]. Th displmnt urv of hydrauli ylindr 10 is obtaind by simulation as Figur. Th spd urv of th load sondary omponnts is shown in Figur 3. Th prssur urv of th umulator is shown in Figur 4 [6]. Figur. Displmnt urv of hydrauli ylindr 10. Figur 3. Spd urv of load sondary omponnts 7. Figur 4. Prssur urv of umulator. Th simulation rsults ar as follows: Movabl arm dlin an b dividd into thr stags: lration, stability and dlration. during th lration phas, and th potntial nrgy of th lifting systm has bn transformd to kinti nrgy to mak th working dvi to lrat th dlin, whil driving a load sondary lmnt rotation spd. At th stag of stabl opration, ontrol systm filling umulator with liquid by ral-tim rgulating th displmnt of th storag sondary omponnt, th potntial nrgy has bn transformd into hydrauli nrgy. In th dlration stag, by ral-tim rgulating th displmnt of th storag sondary omponnt, th kinti nrgy and potntial nrgy hav bn onvrtd into hydrauli nrgy and dpositd in th umulator to raliz th movabl arm rapid brak. At th movabl arm lifting stag, th umulator drivs th storag sondary omponnt rapid lrating. Th ontrol systm adjusts th displmnt of th load sondary omponnt to lift th movabl arm in ral tim.

5 Th rovry nrgy is 0 whn th movabl arm is lrating to dlin. Aftr th ompltion of th movabl arm dlining, th umulator prssur is inrasd from th initial 1MPa to.6mpa, whih ralizs th rovry of potntial nrgy. Conlusions Th flow oupld sondary hydrauli lifting systm of th xavator bukt, whn it workd in non-onstant prssur ntwork, ompard to th prssur oupld of onstant prssur ntwork, its prssur rang was xpandd. So by ontrolling th umulator, th nrgy ryling was ralizd, this would nsur highr oil prssur of th umulator, th rusabl fft was improvd. With sondary rgulation flow oupld ontt hydrostati transmission thnology, th gravitational nrgy of th xavator bukt and load an b rlaimd in th falling pross, and an b rusd in th lifting pross of th xavator bukt and load. So th ngin installd powr has bn rdud to hiv th purpos of nrgy saving and nvironmntal prottion. Rfrns [1] Y. H. Liu, J. H. Jiang. Mathing powr of flow oupld systm with sondary rgulation. Journal of Nanjing Univrsity Sin and Thnology, 007, 31(6): [] J. B. Hu, X. L. Guo and S. H. Yan. Dynami hartristis of hydrostati sondary ontrol load simulation systm and th approh to rsist load disturban[j]. Transtions of th Chins Soity for Agriultural Mhinry, Vol.39(008),p: [3] Yu Anai, J.H. Jiang. Rsarh on nrgy rovry ontrol of a hydrauli hybrid xavator[j]. Journal of Harbin Enginring Univrsity, 01, 33(1): [4] M.Y. Kim, CO. L: Control Enginring Prti. Vol. 14(006), p [5] R. Q. Ao, K. Yuan, Bijing: Srvo-systm, ditd by Aviation Industry Prss [6] Zhang Shuzhong, Dng Bin, Cao Shusn t al. Enrgy flow of a hydrauli xavator with load indpndnt flow distribution[j]. Mhanial Sin and Thnology for Arosp Enginring, 010,9 (1): 94 ~ 99.