A concept for Vertical Folding Convertible Design

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1 The th IFToMM Worl Congress, Tpe, Twn, Octoer -0, 0 DOI Numer: 0./IFToMM.TH.WC.PS.00 A concept or Vertcl Folng Convertle Desgn Hsng-Hu Hung Chng-Yu Weng Sheng-u T Deprtment o Vehcle Engneerng, Ntonl Pngtung Unversty o Scence & Technology Shueu o, Nepu, Pngtung Twn,.O.C Astrct: Ths stuy m on vertcl olng convertle oy esgn. The ptents n relte exstng esgns re collecte or nlyzng to otn the esgn requrements n constrnts. Ths wll cltte new esgn o mechnsms n lso help or the rrngement o the lnkges n roo pnels. The new esgn then e prtculrze n vere y the nlyss o ngulr splcement, ngulr velocty, ngulr ccelerton, n lncng torque y vector loop metho n vrtul work metho. Keywors: Hrtop, vector loop, vrtul work I. Introucton The roo o hrtop roo vehcle s me o sheet metl n hrmones wth the oy lne. Its weght n mnucturng cost re hgher thn sot one, the strength o ts mechnsm s goo; thus, the rgty n sety o the whole cr s etter. However, snce the hrtop roo s non-electve, lrger storge spce s neee n the usle spce o the trunk woul e reuce []. Ths stuy ocuses on vertcl olng hrtop roo mechnsm, n the exste esgns re serche n nlyze. The new mechnsm type o hrtop roo coul execute convertng esly woul e oun out. Then, employ the vector loop n vrtul work metho or escrng n veryng the eslty o the mechnsm. II. Desgn proceure To synthess new types o hrtop roo mechnsm ccorng to the cretve esgn metho[], nlyss the exstng esgns n ptents or numer synthess n lst ll knemtc chn tls or the speclze chn s the rst step. Desgn requrements n constrnts woul e set or crryng out the speclzton knemtc chn. Knemtc chn woul e pponte ccorng to knemtc chn tls. Then prtculrzton proceures cn e use to sply the esly speclzton knemtc chn nto mechnsm skeleton rwng; thus, the mechnsm o new mechnsm type o hrtop roo woul e otne or urther menson synthess to n the new type mechnsm. The esgn synthess proceure s s shown n Fgure. A. Mechnsm Chrcterstcs The esgn o hrtop roo s consttute y ront roo pnel n rer roo pnel whch cn cheve the uncton ccorng to the rver s nee y convertng the structure. Fgure Desgn proceure The propose esgn cn e retrcte y rvng y the ctutor, the rer roo pnel then sl own to the trunk, rve the coupler lnkges to rotte the ront pnel nto the trunk n ront o the rer pnel or completng the retrct o convertle hrtop roo esgn, s shown n Fgure. () pnel exten () pnel retrct Fgure convertle hrtop roo cr esgn The esgn o hrtop roo nee to ppont the open n retrcte locton o ront roo pnel n rer roo pnel. In orer to cltte the moton, ths stuy consers the mechnsm wth egree o reeom whch constructe y eght-r lnkge wth ten jonts, n connecte the rme, ront roo pnel, n rer roo pnel y the coupler lnk. B. Desgn equrements n constrnts Ater entyng the chrcterstcs o hrtop roo mechnsm, the esgn requrements n constrnts coul e lste ccorngly. The esgn requrements or hrtop roo mechnsm re s ollows:. It hs one groun lnk (G) to x the cr oy.. It hs one ront roo pnel (F).

2 . It hs one rer roo pnel (B). The esgn constrnts o hrtop roo mechnsm re s ollows:. All lnks re revolute jont.. The groun lnk shoul e multple lnk.. The groun lnk cnnot e connecte wth the ront roo pnel. It hs coupler lnk to connect the ront roo pnel wth groun lnk.. The groun lnk connecte wth the rer roo pnel. It hs coupler lnk to connect the rer roo pnel wth groun lnk.. The ront roo pnel cnnot e connecte wth the rer roo pnel.. C. Knemtc chn tls Accorng to the numer synthess, the numer o knemtc chn wth egree o reeom o eght-r lnkge wth ten jont s, s shown n Fgure. Fgure Proceure or speclzton E. Prtculrzton o Knemtc Chn Ater speclzton, the esly speclze knemtc chn then cn e prtculrze to trnsorm nto mechnsm grm; thus, the mechnsm o new hrtop roo type woul e otne. Her we tke type c n Fgure s the exmple or trnsorm the knemtc chn to corresponng grm s shown n Fgure. c c Fgure Knemtc chn tls o eght lnkges ten jonts D. Speclzton o Knemtc Chn Ater ece the knemtc chn tls, the new type mechnsm cn e speclze y ssgnng specc types o lnks n jonts n the vlle tls o generlze chns, suject to certn esgn requrements n constrnts, s clle speclzton. The process s s ollows:. Select xe lnk s the groun lnk(g).. Select lnk or ront roo pnel(f).. Select lnk or rer roo pnel(b).. Select knemtc chn tht meets the esgn requrements. Tke type n Fgure s the exmple or speclzton, the results re s shown n Fgure, elmnte the unstse ones, we stll got vlle ones whch ulll the requrements n constrnts. c Fgure Prtculrzton tls Fgure Prtculrzton Proceure III. Mechnsm nlyss We cn n ths s hr roo mechnsm wth egree o reeom whch rve the mechnsm y the nput power (lnk ), n pull the rer pnel sheet (lnk ) ownwr nto the truck spce tht lso rve the coupler lnkges to rotte the ront pnel nto the trunk n ront o

3 the rer pnel or completng the retrct o convertle hrtop roo esgn, s shown n Fgure. We cn get the ntl estmtons o ech vrle y grphcl metho, such s rwng the poston o ech lnks when, n estmte the ntl estmtons o ech vrle s Tle. t 0 t / t / t Fgure New type retrctle hrtop roo Mechnsm The nepenent vector loop s n shown n Fgure ()- (c), [,] () vector loop () vector loop (c) vector loop Fgure Inepenent vector loop o new hr pnel vehcle mechnsm 0 0 () Seprte ormul ()-() nto sclr orm o the vector loop. cos cos cos cos sn sn cos cos 0 sn 0 cos 0 0 sn cos sn 0 sn cos sn cos sn sn 0 0 cos sn cos cos sn cos sn 0 sn sn cos cos sn sn 0 () Where s the nput, n,, n re known constnts, n others re unknown vrles. Then solve equtons ()-() y numercl soluton to otn the ngulr splcement, n erentte the equtons or the ngulr velocty n ccelerton. Ater menson synthess, s shown, the moton o ths mechnsm hs een ece. To mke sure the chrcterstcs n perormnce o the mechnsm, the expresson or nlyzng the mechnsm shoul e estlshe. The Vector Loop Metho hs een use or nlyzng the poston, ngulr velocty, n ngulr ccelerton to otn the reltonshp o ech lnk. An the Vrtul Work Metho s lso use to clculte the requre torque or lnce the system. A. Angulr splcement () () () () () () () Tle The ntl estmtons o ech vrle mm mm mm mm mm 0 mm ' mm mm mm 0 0 0mm mm mm 0 ' mm ' Accorng to the results o ngulr splcement nlyss, the reltonshps o knowns n unknowns cn e oun out, s shown n Fgure. Angulr poston o Angulr poston o Angulr poston o Angulr poston o Angulr poston o Angulr poston o Fgure Chrt o ngulr poston

4 B. Angulr velocty Derentte equton ()~() wth respect to tme to get the ngulr velocty n plotte the chrt o relton etween the knowns n unknowns, s shown n gure 0. Angulr velocty o Angulr velocty o The new type hrtop roo mechnsms re compose y lnks n 0 jonts, n the lnks re connecte to ech other n vre every stte. Forces etween the requre orce n the weght o the pnels cn e erve y vrtul work metho[-]: Ue U 0 (0) Where δue s the vrtul work o the lnce torque, n δu s the vrtul work o weght o pnels. Ue M q () Where M reer to the lnce torque, n vrtul splcement o the lnce torque. q s the U F r () Angulr velocty o Angulr velocty o Angulr velocty o Angulr velocty o Fgure 0 Chrt o ngulr velocty C. Anlyss o ngulr ccelerton Derentte the ngulr velocty wth respect to tme to get the ngulr ccelerton n plotte the chrt o relton etween the knowns n unknowns, s shown n gure. Angulr ccelerton o Angulr ccelerton o Angulr ccelerton o Angulr ccelerton o Angulr ccelerton o Angulr ccelerton o Fgure Chrt o ngulr ccelerton D. Force nlyss The ssumptons re me or orce nlyss o the hrtop roo s ollow:. The weght o the lnks n the rcton o the jonts cn e gnore reltve to the pnels o the hrtop roo..the nert orce cn e gnore ecuse the pnels move slowly. The two ssumptons smple the nlyss. Where F e the weght o pnels n r e the vrtul splcement o the pnel. Frst, the generlze coorntes cn e ene. Deuct the xe lnk, there re stll seven movle lnks, thereore we nee seven generlze coorntes or escre the reltonshps etween these lnks o ths mechnsm. The mechnsm hs one egree o reeom, there exst only one nepenent generlze coornte q, n others re epenent generlze coorntes q, then the reltonshp etween q,n q cn e erve. The mechnsms hve three nepenent vector loops whch cn e ecompose s Equtons ()-(), n erentte equtons ()-() respect to generlze coornte to get constrnt Jcon mtrx [Jc]. q q q q q q q q q q q q q q q q q q q q q J c q q q q q q q q q q q q q q q q q q q q q The vrtul splcement cn e expresse s, q 0 () J c () Where J c nclues n nepenent generlze coornte J n epenent generlze coornte J c c. q nclues n nepenent generlze coornte constrnt mtrx coornte constrnt mtrx rerrngng s: J J 0 c c q n epenent generlze q. The equton cn e q () q Expnng n rerrngng the equton:

5 q J c J cq Susttute equton () nto q n : q q q J c J c q I q J c J c q G I ewrte equton () s: G J c J c I q q () q to get relton o () () Equton () contns the reltonshp etween vrtul splcement generlze coornte n vrtul splcement nepenent coornte. The vrtul splcement Crtesn coornte cn e expresse y vrtul splcement nepenent coornte: J G r q () Where J s the Trnsormton Jcon Mtrx etween the vrtul splcement generlze coornte n vrtul splcement Crtesn coornte. Susttute equton () nto () n rewrte t s: J G U F q (0) Susttute equton (0) nto (0) n rewrte t s: M J G q F q () ewrte equton () s: J G M F () Where M s the lnce torque o the mechnsm, n the orce grm s s shown n Fgure. n J c pnel weght support y the mechnsm cn e expresse, susttute nto equton() to get G. The s [ F], whch nclue W n Crtesn coornte: [ W. Expresse [ F] s F] 0 W 0 W () The locton, where orce W n W ct, s the center grvtes o rer pnel n ront pnel. The stnce etween the center grvtes o the pnels n the orgn o the coorntes: W x cos ( ) cos () W y sn ( ) sn () W x cos cos ( ) cos () W y sn sn ( ) sn () Where x, y, x, y re the stnce etween the pnel weght W n W to the orgn o the coorntes. Derentte the generl coornte to get the Trnsormton Jcon Mtrx etween the vrtul splcement generlze coornte n vrtul J. splcement Crtesn coornte Ater hvng G, [ F], n J, susttute nto equton () to clculte the lncng torque o the mechnsm n plotte the chrt o relton etween the knowns n unknowns, s shown n Fgure. Fgure Anlyss result o lncng torque M : the lnce torque W : the weght o rer pnel W : the weght o ront pnel Fgure Deployment o hrtop roo The lnce torque M expresse y nepenent generl coornte regrng to, others re epenent generl coornte. Accorng to the nonlner equtons, we cn get the Jcon Constrnt Mtrx J c y vrtul work metho. Where J c nclue epenent generl constrnt mtrx J c n n nepenent generl coornte constrnt mtrx J. Then we hve c J c IV. Conclusons The stuy nlyzes the ptents n ppers to get the whole pcture o the mechnsm o the eght lnks n ten jonts hrtop roo mechnsm. Then conclue the requrements n constrnts to cltte the new esgn process n the skeleton o the new esgn. Ater get the new esgn o eght lnks n ten jonts hrtop roo mechnsm, we cn ervte the ngulr splcement, ngulr velocty, ngulr ccelerton, n the requre lncng torque or the mechnsm y vector loop metho n vrtul works metho. Acknowlegment

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