BIW-panels design conceopt panel operations

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1. Design Guide lines for BIW panels
While designing matching radius of reinforcement should have bigger than
the inner panel radius to accommodate irregularities due to die wear.
Panel
Reinf.

2. Front Door
Design Guide lines for BIW panels (Contd.)

3. Design Guide lines for BIW panels (Contd.)
Any part ending against bending/stepped part minimum 3mm
clearance should be followed from the fillet end.

4. Rear Door
Design Guide lines for BIW panels (Contd.)

5. Design Guide lines for BIW panels (Contd.)
When two overlapping parts are welded we need to provide a joggle. The following dimensions need to be
maintained: X=5mm minimum, P= joggle depth equal to thickness of the part1.

6. Front Door
Rear Door
Design Guide lines for BIW panels (Contd.)

7. When two welding flanges are ending with same edge, one welding flange should have
1.7mm clearance from the other welding flange edge.
When three welding flanges are ending with same edge follow the clearances as per
below image.
15-20.0 mm width for weld flange
3
1.7
Design Guide lines for BIW panels (Contd.)

8. Front Door
Body side
Design Guide lines for BIW panels (Contd.)

9. To ensure proper sealing on body side at B-pillar corner area it is necessary to reduce
flange length as per below image
L
L-2
L
R
R=minimum 45mm
Recommended 70mm
For moulded joints
R=minimum 35mm
Design Guide lines for BIW panels (Contd.)

10. On every part extremity of door seal flange surface give 10x3 chamfer or 5mm radius to
match with body side for easy assembly and to avoid injuries during manipulation.
Design Guide lines for BIW panels (Contd.)

11. R
e
a
r

D
o
o
r
Design Guide lines for BIW panels (Contd.)

12. For rectangular or square holes minimum 3mm radius must be given, 1mm radius or
less can potentially generate cracks.
4 CORNERS R (min.)= 3mm
R
R R
R
Design Guide lines for BIW panels (Contd.)

13. Ensure for flanged holes (any shape) flange height should be minimum 3Tmm
(T=Thickness of the part)
Rear Door
Design Guide lines for BIW panels (Contd.)

14. Ensure that the dimensions shown in the image are maintained for pierced or
extruded (flanged) holes.
R= Bend radius
r= Radius of pierced hole
T= Thickness of the component
2r
2r
6r
Design Guide lines for BIW panels (Contd.)

15. Design Guide lines for BIW panels (Contd.)
Case-1: Ensure minimum 40mm overlapping length for assembly of two spot welds
Case-2: For one spot weld
Case - 1 Case - 2
25

16. Design Guide lines for BIW panels (Contd.)
Minimum flange width after fillet considered for spot welding is 12mm
In straight zones spot welding pitch should be 50mm for 5 mm diameter of spot
Rear Door
1
2
5
0
X
X

17. Design Guide lines for BIW panels (Contd.)
While designing reinforcement for inner panel other than welding surfaces it is
necessary to provide minimum 5mm clearance in between reinforcement and inner
panel.
B-Pillar

18. Rear Door
Design Guide lines for BIW panels (Contd.)

19. Design Guide lines for BIW panels (Contd.)
Maintain following rule for bending corner radius R.
R=3X
R= corner radius
X= step height
R
X

20. Design Guide lines for BIW panels (Contd.)
Necessary to provide E-coat drain holes in lower areas (box sections) like closures and body
side sill.
Elpo drain
hole
Front Door

21. Design Guide lines for BIW panels (Contd.)

Ensure following conditions for hemming.
Closures
Wheel arch
7-12
7-12
7-12

22. Tail Gate
Design Guide lines for BIW panels (Contd.)
For mastic application minimum clearance kept in between inner and outer panel is
2mm.
Total depth considered for mastic sealant is 5mm.

23. Hood
Design Guide lines for BIW panels (Contd.)
In outer panels relief is provided on flanges at bending before hemming
operation to prevent folding of material.

24. Design Guide lines for BIW panels (Contd.)
While designing inner panels (roof/ lift gate/door) at water proof area minimum flat
surface against seal must be 20mm. Package seal with a 3 to 5mm crush, in body position.
Lift Gate bottom

25. Design Guide lines for BIW panels (Contd.)
In order to strengthen component against bending (deflection) stiffener/beads to be
provided along the length of the component to protrude in opposite direction to the
bending force applied.
Minimum bending radius considered is 5T.
Stiffener/
bead
Bending
radius

26. Design Guide lines for BIW panels (Contd.)
Ensure mounting locations made stiffen by raising surface locally as shown.
Rear Door

27. Design Guide lines for BIW panels (Contd.)
Following is the fixing method in hinge area and brackets with inner panels
Lift Gate top

28. Rear Door
Design Guide lines for BIW panels (Contd.)
Avoid deep draw depths by gradually reducing depth as a slope or steps of lesser depths.
Steps

29. Design Guide lines for BIW panels (Contd.)
Minimum draft angle for sheet metal part is 10degrees with respect to stamping direction.
Rear Door

30. Design Guide lines for BIW panels (Contd.)
Component is design to its outer surface (class A) as it is visible surface.
Outer panels are generally designed to thickness range of 0.8 to 1.0 mm to meet
performance of denting and hail storm requirement.
Inner panels are generally designed to thickness range of 1.0 to 1.6 mm.
Smooth & large fillet is provided between connecting sections to prevent failure due to
bending.
Design has to meet performance while balancing Mass, Piece cost & tooling investment.