co m p o n en t s wh en set t in g u p t h e p ress fo r a n ew p ro d u ct . O t h er u n i- versally u sed exch an ge t o o lin g co m p o n en t s rem ain in t h e h o ld in g
sleeves. Th e exch an ge t o o lin g in clu d e m ain ly p ressu re p lat es, p ressu re p in s, sp rin g elem en t s an d gu id e sleeves. Fo r t h e st ru ct u ral d esign o f
act ive an d exch an ge co m p o n en t s o f d ie set s, p lease refer t o t h e VDI Gu id elin es 3176, 3186 Sh eet s 1 t o 3.
6.7.1 Die holders
Th e d ie h o ld ers h o ld bo t h t h e act ive an d exch an ge t o o lin g co m p o - n en t s. Th eir fu n ct io n is t o en su re t h at t h e lo wer an d u p p er d ie o p erat e
as o n -cen t er as p o ssible in relat io n t o each o t h er. Th e n u m ber o f st a- t io n s, t h e d ist an ce bet ween st at io n s an d t h e h o ld er sizes are gen erally
gro u p ed t o get h er in st an d ard ized series. Table 6.7.1
illu st rat es a m o d u -
488
Solid forming Forging
Fig. 6.7.3
Section through a die holder w ith w edge adjustment and hydraulic sleeve clamping
die holder pressed part
die holding sleeves active components
exchange components part-dependent exchange
components w edge adjustment
clamping individual station active and
exchange dies
auxiliary column
intermediate die sleeve
die holding sleeve
pneumatic pad
hydraulic sleeve
clamping by means of
w edge clamp
conical retainers
Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998
lar syst em o f t h is t yp e fo r a u n iversal p ress d esign freq u en t ly u sed fo r fo rm in g p art s o f ap p ro x. 0.1 t o 15 kg. O f co u rse, o t h er co m p o n en t an d
d ie sizes can also be im p lem en t ed . Th e d ie ch an ge syst em is clo sely lin ked wit h t h e d ie h o ld er d esign .
Th e ran ge o f p art s t o be p ro d u ced an d t h e in d ivid u al bat ch sizes are t h e m ain crit eria t h at in flu en ce t h e d ie h o ld er d esign an d t h e layo u t o f t h e
d ie ch an gin g syst em . Th e co m p let e d ie h o ld er ch an ge, req u ired wh en st art in g wo rk o n a
co m p let ely n ew p art , in vo lves m o vin g t h e en t ire d ie h o ld er o u t o f t h e m ach in e t o be rep laced by a read y-p rep ared h o ld er lo cat ed in a p re-
scribed wait in g p o sit io n . Th e d ie h ead an d base p lat e o f t h e d ie h o ld ers are h yd rau lically clam p ed
Fig. 6.7.1 . Fo r m o vin g in an d o u t o f t h e
p ress, t h e u p p er an d lo wer p art are m o ved t o get h er by m ean s o f au xiliary co lu m n s an d lo cked t o get h er wit h safet y st rap s fo r t ran sp o rt
Fig. 6.7.2 . A t h ird d ie h o ld er can be assem bled an d set -u p in t h e d ie
sh o p d u rin g t h e p ressin g o r exch an gin g t h e d ie h o ld ers. Fo r t h is m et h o d o f d ie h o ld er exch an ge, p art s o f t h e grip p er rails h ave t o be
u n co u p led , fixed o n t h e d ie h o ld er an d rem o ved t o get h er fro m t h e p ress. Dep en d in g o n t h e size o f t h e h o ld er, t h e exch an ge can t ake an y-
wh ere bet ween 20 an d 40 m in . Th ese t im es in clu d e reset t in g o f t h e feed in g st at io n an d , in t h e case o f warm p ressin g, o f t h e in d u ct io n fu r-
n ace as well. In exch an gin g t h e sleeves, t h e base an d t h e h ead p lat e are left in t h e
p ress an d t h e sleeves in t h e t able an d slid e are rep laced in d ivid u ally. Fo r t h is p u rp o se, t h e base an d h ead p lat e are fast en ed at t h e bed an d slid e.
Th ey are eq u ip p ed wit h co n ical cen t erin g rin gs Fig. 6.7.3
an d 6.7.4
.
489
Die design
Table 6.7.1: M odular system for possible die holder sizes w idths bold = frequently used sizes for
number of and distance betw een stations Number of stations Die holder w idths w ith distances betw een stations in mm
200 250
300 350
400
2 400 500 600750 700 800 3 600 750 9001,000 1,050 1,200
4 800 1,000 1,2001,250 1,4001,500 1,600 5 1,000 1,250 1,500 1,850 2,000
6 1,2001,250 1,500 –
– –
Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998
Each d ie h o ld in g sleeve is fast en ed by m ean s o f t wo t o fo u r h yd rau lic wed ge-t yp e clam p s
Fig. 6.7.3 . Th is d esign is u sed fo r large bat ch sizes
wh en t h e t o o ls wear at very d ifferen t rat es in t h e in d ivid u al st at io n s an d h ave t o be in d ivid u ally rep laced . In t h is case, read y p rep ared d ie
h o ld in g sleeves are lo cat ed in a p rescribed lo ad in g p o sit io n an d can be m o u n t ed in t o t h e d ie st at io n by a d ie ch an gin g arm cf.
Fig. 3.4.5 . It
t akes bet ween 4 an d 8 m in t o rep lace o n e sleeve. Figures 6.7.3
an d 6.7.4
illu st rat e t h e u se o f in t erm ed iat e sleeves wh ich can be assem bled wit h axial p re-st ressin g. Mu lt ip le-st at io n fo rgin g p erm it s su bseq u en t o p era-
t io n s t o be execu t ed in o n e p ro cessin g st ep . As illu st rat ed in Fig. 6.7.4
an d 6.7.5
, in t h e case o f t h is sp ecific d ie h o ld er, t h e en d o f t h e ext ru d - ed sh aft is sh eared t o t h e req u ired len gt h by a wed ge-act io n p u sh er d ie
in t h e fo u rt h d ie st at io n .
490
Solid forming Forging
Fig. 6.7.4
Four-station die holder w ith hydraulic sleeve clamping and shearing station in the fourth station
Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998
6.7.2 Die and punch design
