Control systems for blanking presses

Th e clam p in g p late is eq u ip p ed with electroh yd rau lically actu ated clam p in g d ogs wh ich are retracted in th e area of a p erforation close to th e m aterial ed ge, so elim in atin g th e n eed to reclam p th e sh eet m etal p late. Su p p ort rails eq u ip p ed with rollers wh ich can be m oved as req u ired on th e clam p in g p late are p osition ed in fron t of an d beh in d th e d ie to p reven t u n wan ted saggin g of th e sh eet m etal p late. Th is system allows to red u ce th e m ass of in ertia to a q u arter of th at of th e old -style solid con stru ction clam p in g p lates. Used in con ju n ction with m od ern op tim ized h igh -p erform an ce actu ators, extrem ely sh ort traversin g p eri- od s of for exam p le 0.2 s with a feed len gth of 80 m m can be ach ieved .

4.6.7 Control systems for blanking presses

Th e co n cep t o f p ro d u ct io n cells an d t eam wo rk is bein g in t ro d u ced in p ro d u ct io n an d assem bly p lan t s in o rd er t o im p ro ve flexibilit y, q u alit y an d also p ro d u ct ivit y. Th is in vo lves ext en d in g t h e resp o n sibilit y o f each gro u p o r sin gle wo rkp lace t o in clu d e p lan n in g, in sp ect io n an d m ain t en an ce act ivit ies. As a resu lt , st ru ct u res will beco m e in creasin gly d ecen t ralized in t h e fu t u re. Th e great er d egree o f au t o m at io n resu lt in g fro m t h is d evelo p m en t will in evit ably lead t o m ach in es an d p ro d u ct io n lin es o f ever great er co m p lexit y. At t h e sam e t im e, o p t im u m o p erat in g an d m ain t en an ce cap abilit y as well as h igh eq u ip m en t availabilit y m u st be ach ieved . Th is m ean s t h at d ecen t ralized u n it s m u st t ake in creasin g resp o n sibilit y fo r t h e p ro visio n an d u p d at in g o f p ro d u ct io n an d eq u ip - m en t -relat ed d at a an d in fo rm at io n at t h e p o in t o f it s gen erat io n . A vari- et y o f t ech n ical aid s m u st be m ad e available t o en able t h e m ach in e o p erat o r t o avo id o r q u ickly rem ed y an y m ach in e st an d st ill. Inform ation technology It is n ecessary to h ave an op eratin g an d in form ation system , in tegrated in th e m ach in e con trol, th at m u st fu lfil th e followin g criteria Fig. 4.6.34 : – a sim p le, easily u n d erst o o d syst em o f o p erat o r su p p o rt wh en set t in g t h e o p erat in g p aram et ers fo r st art -u p an d resu m in g o p erat io n fo l- lo win g a d ie ch an ge o r m ach in e failu re, – a t o o l d at a m an agem en t syst em t h at h as an o verview o f exist in g d ies an d relat ed feat u res as well as m ach in e p aram et ers an d t h at p erm it s sim p le access an d ed it in g, 320 Sheet metal forming and blanking Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998 – p ro visio n o f all im p o rt an t d at a t o t h e o p erat o r d u rin g p ro d u ct io n , t o allo w o n -go in g assessm en t o f m ach in e st at u s, – su p p o rt fo r t h e o p erat o r in t ro u blesh o o t in g an d rep air wo rk in case o f m ach in e failu re, – clearly arran ged in d icat io n o f m ain t en an ce in t ervals an d in st ru c- t io n s o n t h e execu t io n o f n ecessary wo rk, – p ro d u ct io n lo g t o in fo rm t h e o p erat o r o n t h e t yp e an d t im e o f p revi- o u s fau lt s an d m ain t en an ce wo rk – o p erat o rs m u st be able t o en t er an d access t h eir o wn co m m en t s, – a so ft ware syst em wh ich is su fficien t ly o p en -en d ed t o allo w o t h er ap p licat io n s su ch as jo b m an agem en t , q u alit y assu ran ce, o p erat io n al d at a acq u isit io n o r rem o t e d iagn o st ics. Co m p lian ce wit h all t h ese req u irem en t s im p o ses st rin gen t d em an d s o n t h e co n t ro l an d in p art icu lar o n t h e so ft ware syst em . W h ile t h ese req u irem en t s exceed t h e cap abilit y o f a p ro gram m able lo gic co n t ro ller PLC, in d u st rial PCs p o ssess p ract ically all t h e co m p o n en t s n ecessary fo r co m p lian ce wit h t h ese sp ecificat io n s. Th e in d u st rial PC is n o t o n ly h igh ly efficien t , bu t also ben efit s fro m an o p en -en d ed so ft ware syst em , o fferin g grap h ic u ser in t erfaces an d o bject -o rien t ed p ro gram m in g t h ro u gh t h e u se o f p o werfu l p ro gram m in g t o o ls. 321 Shearing lines Fig. 4.6.34 Demands made on modern operating and visualization systems Production operating, monitoring signalling tool data management Operating parameters Acquisition of operational data M aintenancerepairs maintenance execution log production data, machine data, statistics line operating and information system input and editing of process parameters Failure diagnostics error message failure diagnostics Job preparation job sheet, job management remote diagnostics documentation quality assurance measurement-control documentation Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998 Th e wid esp read p o p u larit y o f MS Win d o ws as a grap h ic u ser in t erface h as p ro vid ed a p lat fo rm fo r m an y so ft ware su p p liers t o o ffer efficien t so ft ware so lu t io n s – also in t h e field o f p ro cess visu alizat io n , wh ich p ro - vid es u sers wit h an ergo n o m ically co n figu red rep resen t at io n o f p ro d u c- t io n seq u en ces. Th ro u gh in t egrat io n in MS win d o ws, co m m u n icat io n is p o ssible wit h o t h er Win d o ws ap p licat io n s via t h e “d yn am ic d at a exch an ge DDE” in t erface. Drivers fo r t h e relevan t PLC syst em s are req u ired fo r co m m u n icat io n bet ween t h e p ro cess visu alizat io n syst em an d t h e “p ro gram m able lo gic co n t ro ller PLC”. Line operating and inform ation system Th e lin e o p erat in g an d in fo rm at io n syst em ABI-Plu s is a m o d u lar, o p en -en d ed an d flexible so ft ware syst em d esign ed t o ad d ress p resen t an d fu t u re p ress au t o m at io n req u irem en t s. ABI-Plu s h elp s red u ce m ach in e an d p ro d u ct io n lin e st an d st ill p erio d s, an d so co n t ribu t es t o ward s im p ro ved p ro d u ct ivit y as well as great er flexibilit y. Process visualization Fo r ABI-Plu s, a st an d ard co m m ercially available p ro cess visu alizat io n syst em was select ed as t h e co re o f t h e o verall syst em . Th e o p erat o r is able t o m o n it o r an d co n t ro l t h e p ro cess eit h er in t eract ively o r au t o - m at ically t h ro u gh t h e co n t ro l syst em . Th e m an -m ach in e in t erface p ro - vid es an o p t ical rep resen t at io n o f t h e m ach in e st at u s wit h t h e aid o f d yn am ic grap h ics an d real im ages Fig. 4.6.35 . In t erven t io n in t h e p ro cess is p o ssible u sin g t h e so ft keys. Th e u ser is gu id ed t h ro u gh t h e vario u s o p erat in g m o d es su ch as set -u p , au t o m at ic co n t in u o u s o p erat io n o r d ie ch an ge o n a st ep -by-st ep basis. Th e p ro cess p aram et ers are en t ered u sin g an alp h an u m eric keyp ad an d feasibilit y t est ed by t h e p ro gram . If a m ach in e erro r o ccu rs, t h e relevan t erro r m essage wit h d at e an d t im e is su p erim p o sed o n t h e screen m ask cu rren t ly bein g u sed . Th e o p erat o r is able t o access t h e t ro u blesh o o t in g m o d u le in o rd er t o lo cal- ize t h e fau lt an d rem ed y it if n ecessary. Th e n eed o f a m ach in e m ain t e- n an ce in t erval is also in d icat ed t o t h e o p erat o r by m ean s o f a flash in g m ain t en an ce sym bo l. Tool data m anagem ent An o t h er m o d u le o f t h e ABI-Plu s is a co m p reh en sive t o o l d at a m an age- m en t syst em wh ich allo ws all d ie-sp ecific d at a an d m ach in e set t in gs t o 322 Sheet metal forming and blanking Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998 be en t ered , ed it ed , st o red an d t ran sferred t o t h e PLC Fig. 4.6.36 . Fo r all o f t h ese act ivit ies, t h e o p erat o r is o ffered su p p o rt in t h e fo rm o f sym - bo ls an d grap h ic im ages, as well as bein g able t o d elet e, ren am e an d co p y t o o l d at a reco rd s at will. Th e n u m ber o f t o o l d at a reco rd s wh ich can be st o red d ep en d s o n t h e st o rage cap acit y o f t h e in d u st rial PC. Failure diagnostics m odule If a m ach in e failu re is sign alled , t h e o p erat o r is able t o access t h e failu re d iagn o st ics m o d u le by p ressin g a so ft key an d h ave t h e p o ssible erro r cau ses an d t h e relevan t rep air p ro cess wit h t h e n ecessary wo rk st ages d isp layed o n screen Fig. 4.6.37 . Fo r each wo rk st age, an in st ru ct io n t ext wit h a real im age an d , wh ere n ecessary, also circu it d iagram s, h yd rau lic p lan s o r t ech n ical d rawin gs are d isp layed . Th e relevan t sec- t io n o f t h e illu st rat io n is h igh ligh t ed by an ico n . For each error m essage, th e op erator is able to en ter th e d ate, th e n am e of th e p rocessin g staff m em ber an d a com m en tary for th e record s. 323 Shearing lines Fig. 4.6.35 M achine status display Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998 Maintenance m odule Th e m ain ten an ce sign al is p rovided in th e form of a flash in g m ain ten an ce sym bol to in dicate to th e op erator th at m ain ten an ce is du e. A table with color-coded bars, wh ich can also be accessed du rin g p rodu ction , in dicates all th e m ain ten an ce in tervals Fig. 4.6.38 . Th e op erator accesses th e m ain ten an ce m odu le u sin g a softkey. Th e in dividu al work step s of th e m ain ten an ce activities are in dicated by an in stru ction text with a real im age assign ed to it Fig. 4.6.39 . In addition , every work stage can be fu r- th er illu strated by accessin g a circu it diagram , h ydrau lic p lan or tech n ical drawin g. Here too, it is p ossible to store p rodu ction log in form ation su ch as date, n am e of th e op erator an d com m en tary. Electrical equipm ent As a ru le, t h e elect rical eq u ip m en t o f t h e p ress is bro ken d o wn as fo l- lo ws: – o p erat in g an d in fo rm at io n syst em wit h swivel-m o u n t ed p en d an t co n t ro l u n it – su p p ly, d ist ribu t io n an d elect rical co n t ro l in t h e swit ch cabin et 324 Sheet metal forming and blanking Fig. 4.6.36 Tool data display Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998 325 Shearing lines Fig. 4.6.37 Failure diagnostics module Fig. 4.6.38 Overview of the maintenance module Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998 – d ecen t ral I O m o d u le at t h e p ress, at t h e feed u n it , at t h e h yd rau lic an d lu bricat io n syst em s an d in t h e p en d an t co n t ro l u n it – sen so rs an d act u at o rs at t h e p ress, at t h e feed u n it an d at t h e h yd rau lic an d lu bricat io n syst em s – m ain p ress d rive syst em Dep en d in g o n t h e co n figu rat io n o f t h e p ress lin e, a ran ge o f p erip h - eral d evices an d u n it s su ch as co il lin es wit h st raigh t en in g m ach in es cf. Sect . 4.3 an d reco ilers o r co il lu bricat io n d evices are ad d it io n ally u sed . Th ese are eq u ip p ed wit h t h eir o wn co n t ro l syst em s, sen so rs an d act u at o rs. Structure of the operating unit Th e o p erat in g u n it co m p rises an in d u st rial PC fo r lin e o p erat io n an d m o n it o rin g, t o o l an d m ach in e d at a m an agem en t , as well as in fo rm a- t io n syst em fu n ct io n s fo r t h e elim in at io n o f failu res as well as backu p d u rin g m ain t en an ce an d rep airs Fig. 4.6.40 . Basic an d safet y fu n ct io n s are su p p o rt ed by keys, swit ch es an d lam p s. 326 Sheet metal forming and blanking Fig. 4.6.39 M aintenance instructions Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998 Structure of the electrical control system So m e o f t h e sp ecial fu n ct io n s n o t d escribed in t h e Sect io n “Press co n - t ro l syst em s” will be illu st rat ed h ere u sin g t h e exam p le o f a h igh -sp eed blan kin g lin e co n t ro l syst em cf. Sect . 3.5 . Figure 4.6.41 p ro vid es an o verview o f t h e syst em st ru ct u re. Th e sen so rs an d act u at o rs in t egrat ed in t h e p ress lin e are co n n ect ed via t h e I O syst em o f t h e cen t ral PLC u n it . Th e wirin g o f t h e p o wer su p - p ly t o t h e swit ch cabin et is ad d ed t o t h is. Dep en d in g o n t h e sco p e o f t h e p ress lin e in q u est io n , t h e t ran sit io n fro m cen t ral t o d ecen t ral I O m o d u les allo ws t h e wirin g in p u t t o be su bst an t ially red u ced : Ret ro fit t in g, m o d ificat io n s, in st allat io n an d t ro u blesh o o t in g are co n sid erably sim p lified . In ad d it io n , t h ere is a m arked im p ro vem en t in elect ro m agn et ic co m p at ibilit y EMC. Com m u n ication between th e PLC an d th e I O u n its at th e p ress lin e ru n s via th e serial field bu s with tran sm ission sp eed s of u p to 12 Mega- bits s. Th e tran sm ission m ed iu m is a sh ield ed twisted -p air cop p er cable. For ap p lication s in en viron m en ts su bject to m arked electrom agn etic 327 Shearing lines Fig. 4.6.40 Control unit Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998 M ain drive system Press L2-DP L2-DP L2-DP L2-DP L2 -D P Feed system Pendant control unit crank position M T encoder slide height slide adjustment feed length setting feed height setting monitoring lubrication flow lubrication manifold pump actuation monitoring pumps system pressures filter and oil level triggering of hydraulic valves die change oil temperature monitoring coil end G G press clutch encoder feed length encoder infeed height activation feed rollers infeed centering device Contact control mode preselection emergency STOP cut-in control protective door safeguard protective doors recoiling coil clamping stroke adjustment stroke adjustment PL C CP U tool safeguard operating elements operating elements Control system stroke adjustment emergency STOP emergency STOP emergency STOP operating elements Link coil line electr. feed system clutch ON reference point mode preselection direct voltage motor monitoring _ industrial PC press safety control PST 3 setpoint input, analog control system el ec tr on ic ca m c on tr ol le r pe ne tr at io n de pt h co nt ro l fe ed le ng th c on tr ol Lubrication Hydraulic system Sh ee t m eta l fo rm in g a nd b la nk in g Fi g . 4 .6 .4 1 Str uc tu ra l b re ak do w n o f th e c on tro l s ys te m in a h ig h- sp ee d b la nk in g l in e Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998 in t erferen ce, o r wh ere bo t h in creased t ran sm issio n ran ges an d sp eed s are in vo lved at t h e sam e t im e, fiber o p t ic cables can be u sed . Dat a co m m u n icat io n t o p erip h eral eq u ip m en t su ch as co il lin es, co il st o ck t h ickn ess gau ges o r co il lu bricat io n syst em s is p erfo rm ed via t h e I O in t erface o f t h e PLC. Bet ween t h e in d u st rial PC an d t h e PLC, d at a co m m u n icat io n is im p lem en t ed via an act ive serial in t erface wit h 20 m A. Fo r d at a co m m u n icat io n wit h a h igh er-level co m p u t er syst em , an ad d it io n al serial in t erface is available in t h e in d u st rial PC. 329 Shearing lines Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998 4 Sheet metal forming and blanking

4.7 Fine blanking