admin
Door ring (B-pillar reinforcement) stamping is one of the most demanding servo press applications.
Why Servo Press for Door Rings:
Door rings are typically stamped from ultra-high-strength steel (UHSS) at 980-1500 MPa. Challenges: high springback requiring precise BDC control, risk of cracking at tight radii if forming speed is too high.
Motion Profile Strategy:
- Approach (TDC to 50mm above contact): Maximum speed 200-300mm/s
- Pre-forming (50mm to 10mm above BDC): Reduce to 80-120mm/s
- Final forming (10mm to BDC): Slow to 20-40mm/s - this is where springback is controlled
- Dwell at BDC: 0.1-0.3 seconds - allows stress relaxation, reduces springback 15-25%
- Return: Maximum speed
Tonnage Requirements for typical door ring blank (1.2mm x 1500MPa UHSS, 800mm x 400mm):
- Estimated forming force: 800-1200 tons
- Recommended press: 1200-1600 ton servo press with 4-point slide guidance
- Typical OEMs: Aida NS2-H series, Schuler MSP series, Komatsu H2F series
mike_chen_eng
If seeing inconsistent springback between left and right side of the part, check slide parallelism before adjusting motion profile. Even 0.03mm tilt across a 1200mm bolster causes asymmetric forming force on UHSS. Chased a springback issue for two weeks before finding a 0.04mm parallelism error.