What is a servo press?

A servo press uses servo motors for precise force and position control during forming operations.

How do I calculate servo press tonnage?

Use our free tonnage calculator at servopress.club/tonnage-calculator.html

Servo Press for Automotive Structural Parts: Lessons from a High-Volume Line

admin

Running a servo press for automotive structural stampings requires tight tolerances, high volumes, and zero defects.

## The Application

Part: B-pillar inner reinforcement, 1.8mm AHSS 980MPa. Annual volume: 240,000 parts. Press: 600-ton servo press, knuckle-joint drive. Die: Progressive die, 8 stations, 400mm feed pitch.

## Why Servo Was Necessary

We tried this part on a mechanical press first. Problems: springback variation of plus or minus 1.5 degrees between start and end of coil, die wear accelerating due to high impact velocity, could not hold the plus or minus 0.3mm flange height tolerance.

The servo press solved all three: springback compensation via 2 degree overbend adjustable per coil, low-impact forming at 50mm/s at contact, consistent BDC position of plus or minus 0.01mm repeatability.

## Motion Profile Development

Approach speed: 250mm/s. Forming speed: 80mm/s. Dwell at BDC: 50ms improved flange height consistency by 40%. Return speed: 600mm/s. Final cycle time: 1.8 seconds = 33 SPM.

## Production Results After 18 Months

Scrap rate: 0.08% versus 0.6% on mechanical press. Die maintenance interval: 500,000 strokes versus 150,000. Cpk on critical dimensions: 1.67 average against requirement of 1.33.

yuki_rnd

B-pillar stamping on servo press is where the technology really shines. We published a study showing that variable speed forming (80 mm/s approach, 30 mm/s through the draw, 50ms dwell) reduced springback by 35% compared to constant-speed forming on 980 MPa steel. The servo's programmability is essential for UHSS.

sarah_mfg_eng

Running 980 MPa at 200K parts/year on our servo line. The key learning: die temperature management is as important as press parameters. We added die cooling channels and monitor die surface temperature. When it exceeds 60?C, springback increases noticeably. The servo press gives you the motion control but thermal management is on you.