8. Bead DevelopmentDie Design Procedure
• Laying out the design for the die
• Detailed drawings of each die part, i.e., punches, punch holders, die
steels
• Design is given to a NC (Neuro-Computing) programmer to
determine the path of the tool
• NC programmer develops the script program
• Input program into the machine controller
• Machine is now ready to create the die
9. Die Panel Design
• Stretch-draw forming is the
process of cold forming sheet
stock over a forming block by a
mating die of the desired
shape while the workpiece is
held in tension.
• Avoid deep drawing- reduces
costs.
• A stretch draw die in an
inverted draw die will eliminate
the need to turn the part over
before placing into the trim die.
13. Redesign 1
• First redesign involved panel
mating with front door
• Three major problems with the
original design
– Panel should not go all the
way down to the bottom of the
car
– Corner would cause
formability issues
– Flanging would more than
likely cause regional tearing
Before
After
14. Redesign 2
• Second redesign involved
panel flanging at the base
• The original panel design had
no way of mating the panel to
the frame other than under the
hood
• Issues still remain here where
beading will more than likely
need to be added to the new
flange for rigidity
Before
After
15. Redesign 3
• Final redesign involved
flanging between panel and
the front door
• The new flange was increased
from just under an inch to over
six inches in length
• The flange is now one of the
more significant attachment
points on the panel
Before
After
16. Die Tip
• The die tip is the next step
in the die design process.
• Here the high point usually
close to the midpoint of the
panel is determined
• Then the horizontal and
vertical distance is
measured from the high
point to the low point of the
panel to develop the binder
wrap.
17. Binder Wrap
•Here the binder wrap is developed from the die tip and the overall shape and curvature
of the panel is laid over the sheet.
•The binder wrap will determine the size and shape of the overall blank.
18. Lower Punch
•The lower punch, the male portion of the draw die was created by extruding the panel
surface off a solid block.
•The formation of the flanges are all placed on a 10-15 degree angle to jump-start the
next die in the process, flanging.
19. Upper Punch
•The upper punch, the female portion of the die was created by subtracting the panel
shape from a solid block.
•The upper punch will be contacted to the upper shoe of the overall die and will integrate
guide pins for positioning and alignment of the mating of the two dies.
20. Draw Bead
• The draw bead is created
around the parameter of the
female or upper punch.
• The draw bead provides
control over the flow of the
metal while strain is applied
during operation.
• The draw bead is sometimes
doubled in places where the
metal is prevented from
flowing.
• The absence of a draw bead
can be utilized as well to allow
full flow of the metal in a place
where extra material is needed
to prevent tearing or wrinkling
