Sheet Metal Forming

358 / Sheet Metal Forming—Processes and Applications
shear spinning
accuracy, 269(T)
applications, 269–270(F)
of a cone, 267(F)
of convex shapes, 267(F)
failure modes, 267–268
circular flaring, 268(F)
circumferential cracks, 268(F)
sufficient part, 268(F)
wrinkling, 267, 268(F)
machines, 268–269
dieless shear spinning, 269(F)
with two symmetric roller tool-heads, 269
overview, 266
part properties, 269
maximum angles, 270(T)
tolerances, 269(T)
preforms of the blank, 268(F)
process description, 266–267
process design, 268
conventional and shear spinning combination, 268(F)
preforms of the blank, 268(F)
process kinematic, 267(F)
tools, 269
wrinkling, 267
sheared dies, 7(F)
shearing, 14(F)
blade clearance, 15
hold-down force, 15
material properties, 15
overview, 14–15
penetration during, 15(F)
rake, 15
ram incline, 14(F), 15
shearing velocity, 15
shearing stresses, 125
sheet bending, 19(F), 20(F)
sheet bulging
bulge height control techniques, 165(F)
die assembly with segmented elastic blank holder, 167(F)
elastic blank holder, 166–167
elastic cushion to form sharp corners, 165
multipoint blank holder control, 165–166
overview, 165
pressure pot with mechanical/elastic cushions, 165(F)
SHF-D, 166(F)
sheet hydroforming
advantages, 158–160
components, 158(F)
counterpunches, 167(F)
elevated temperature application
heated tool, 174(F)
production forming cell, 174(F)
production parts, 174(F)
QPF at General motors, 173
QPF process, 174(F)
industrial applications, 173
limitations, 160
using liquid media, 157(F)
overview, 157
presses
flexform fluid cell press, 164(F)
horizontal SHF-D press, 164(F)
Schuler active hydromechanical process, 163(F)
sheet hydroforming with punch short-stroke press, 
163(F)
SHF-D, 162–164
SHF-P, 162
process economics (
see
sheet hydroforming process 
economics)
process simulation—room-temperature sheet 
hydroforming
application with die, 169(F)
application with punch, 169–170(F)
FE model of trunk lid-outer, 170(F)
optimization of SHF-P process, 170, 171(F)
overview, 169
results, 170(F)
validation, 170
process variations
combination SHF-P process with regular stamping, 
160–161(F)
double-blank hydroforming/parallel-plate 
hydroforming, 162
flexform fluid cell/rubber pad forming, 160, 161(F)
rubber forming, 162(F)
with punch (SHF-P), 159(F)
room temperature applications
flexible multiforming system, 173
high-strength steels, 173
room-temperature system, 157–158
sheet bulging, avoiding (
see
sheet bulging)
SHF-D, 158, 159(F)
SHF-P
bulge formation, 168(F)
defects, 167
fracture, 168(F)
leaking, 168–169(F)
process limits, 167
process window, 167–169(F)
tool design, 164–165
warm sheet (
see
warm sheet hydroforming)
sheet hydroforming process economics
case study I: rear door panel, 175–176(F)
case study II: fifteen body panel parts, 176–177(F)
outputs from calculator, 175(F)
overview, 173–174
SHEETCOST calculator inputs
general inputs, 174
process-related inputs, 174
sheet hydroforming with die (SHF-D)
advantages of, 158–160
blank holder, 158
dent resistance, 159
description of, 157, 158
double-blank hydroforming/parallel-plate hydroforming, 
162
free bulging, 158
limitations, 160
multipoint blank holder control, 165–166(F)

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