4 Sheet metal forming and blanking
4.3 Coil lines
Th e m et h o d o f sh eet m et al feed p lays an im p o rt an t ro le wh en co n sid - erin g t h e o verall co st effect iven ess o f fo rm in g an d blan kin g lin es.
W h en p ro d u cin g sm all sh eet m et al p art s, t h e sh eet m et al co il is fed d irect ly by a co il feed lin e in t o t h e p ress.
Th e fu n ct io n o f t h e co il lin e is t o u n win d co ils o f sh eet m at erial, p ass it t h ro u gh t h e st raigh t en er an d t o feed it by m ean s o f a ro ll feed p re-
cisely t o t h e d efin ed p o sit io n o f t h e p ro cessin g lin e cf. Fig. 4.6.4
. Th e m ain co m p o n en t s o f a co n ven t io n al co il lin e are t h e d eco iler,
st raigh t en in g m ach in e, co il lo o p an d ro ll feed Fig. 4.3.1
. Th e st raigh t - en in g m ach in e d raws t h e co il st o ck fro m t h e d eco iler an d flat t en s
t h e m at erial cf. Sect . 4.8.3
. Usin g su fficien t ly large d im en sio n ed ro ller assem blies – in o rd er t o avo id t h e m at erial fro m beco m in g ben t again –
t h e m at erial is t ran sp o rt ed fro m t h e st raigh t en in g m ach in e co n t in u - o u sly t o t h e co il lo o p . Th e elect ro n ically co n t ro lled ro ll feed d raws t h e
st o ck in t erm it t en t ly fro m t h e lo o p an d feed s it , co rrect ly p o sit io n ed , in t o t h e p ress. Th e m axim u m feed o u t p u t o f a h igh -p erfo rm an ce co il
lin e fo r sm all an d m ed iu m -sized p art s cf. Fig. 4.4.4
an d a blan kin g p ress cf.
Sect s. 4.4.5 ,
4.4.7 ,
4.4.8 is in d icat ed in
Fig. 4.3.2 . Th e st ro kin g
rat e o f t h e p ress is sp ecified d ep en d in g o n t h e feed len gt h an d t h e cran k an gle wh ich is available fo r t h e feed d ep en d in g o n t h e p ress an d t h e
t o o l in u se. Co m p act d esign co il feed in g lin es d o n o t req u ire t h e p it fo r t h e co il
lo o p Fig. 4.3.3
. Th ey co n sist o f a d eco iler an d a feed st raigh t en in g m ach in e. Th e d eco iler u n win d s t h e st o ck d o wn ward s, o p p o sit e t h e
d irect io n o f p ro cessin g, so fo rm in g a h o rizo n t ally align ed co il lo o p . Th e
Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998
feed st raigh t en in g m ach in e d raws t h e st o ck o n an in t erm it t en t basis o ff t h is lo o p , st raigh t en s it an d feed s it , co rrect ly p o sit io n ed , in t o t h e p ress.
W h et h er t h e co n ven t io n al co il feed lin e o r t h e co m p act d esign is u sed d ep en d s o n t h e m at erial t o be p ro cessed . Co il st o ck wh ich is t h in
o r h as a sen sit ive su rface can be very su ccessfu lly p ro cessed u sin g co n - ven t io n al m et h o d s. Ho wever, in cases wh ere gen erally t h ick co il st o ck
is bein g fed t o t h e p ress, an d if t h e m at erial is su it able fo r in t erru p t ed st raigh t en in g, t h e co m p act d esign is gen erally p referred .
W h en wo rkin g wit h p ro gressive d ies an d co m p o u n d d ies, t h e feed st raigh t en in g m ach in e can be released briefly d u rin g im m ersio n o f t h e
p ilo t p in s fo r feed co rrect io n cf. Fig. 4.7.25
. Th is ap p lies eq u ally t o ro ll feed . Fo r ro ll feed , t h e release p erio d is aro u n d 0.03 s an d fo r t h e
feed st raigh t en in g m ach in e aro u n d 0.05 s.
195
Coil lines
Fig. 4.3.1
Coil line for direct feed of stock material into the press
Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998
196
Sheet metal forming and blanking
Fig. 4.3.2
Feed performance diagrams of a blanking press and of a high-performance line for small and medium-sized parts
10 20
30 40
50
500 feed step [mm]
feed performance of a blanking press
st ro
ki ng
ra te
[1 m
in ]
1000 1500
2000 2500
3000 3500
4000 60
70 80
90 100
300 °
270 °
240 °
210 °
180 °
crank angle available for transport
100 200
300 400
500
20 feed step [mm]
st ro
ki ng
ra te
[ 1
m in
]
40 60
80 100
120 140
160 180
200 600
700 800
900 1000
300 °
270 °
240 °
210 °
180 °
crank angle available for transport
feed performance of a high-performance line for small and medium-sized parts
Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998
197
Coil lines
Fig. 4.3.3
Compact design coil line
Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998
4 Sheet metal forming and blanking
4.4 Sheet metal forming lines 4.4.1 Universal presses
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