1 / 37

Servo Press Technology Applications for Today and Tomorrow

Servo Press Technology Applications for Today and Tomorrow. Eren Billur and Taylan Altan Center for Precision Forming The Ohio State University www.cpforming.org & www.ercnsm.org August 23, 2012 . Servo-Drive Presses- Outline . Introduction Servo-Drive Characteristics

acacia
Download Presentation

Servo Press Technology Applications for Today and Tomorrow

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Servo Press TechnologyApplications for Today and Tomorrow Eren Billur and TaylanAltan Center for Precision Forming The Ohio State University www.cpforming.org & www.ercnsm.org August 23, 2012

  2. Servo-Drive Presses- Outline • Introduction • Servo-Drive Characteristics • Servo-Drive Press Mechanisms • Applications • Die Cushions • Summary/ Future Outlook

  3. Servo-Drive Characteristics The flexibility of slide motion in servo drive (or free motion) presses. [Miyoshi, 2004]

  4. Servo-Drive Characteristics • Precise ram position and velocity control, anywhere in stroke-easier set up • Adjustable stroke length (TDC and BDC) • Ram position/ velocity can be synchronized with automatic part transfer • In deep drawing, cycle times can be shorter than in mechanical presses • Considerable savings in energy • Dwell at BDC/ restriking/ vibrating and variable blank holder force (BHF) • Max. motor torque available during the entire stroke

  5. Servo-Drive Mechanisms • Low Torque/ High RPM Motors Use Ball Screws or/and Linkage Mechanisms • High Torque/ Low RPM Motors Use Existing Crank and/or Link Press Drives

  6. High RPM/ Low TorqueMotor Drive 1/2 Schematic of servo press with high speed-low torque servo-motors with belt and ball screw drive. [Miyoshi, 2004]

  7. High RPM/ Low TorqueMotor Drive 2/2 Schematic of servo press with high speed-low torque servo-motors with linkage drive. [Miyoshi, 2004]

  8. Low RPM/ High TorqueMotor Drive 1/2 Power Source Balancer tank Main gear Capacitor Servomotor Drive Shaft b) Stroke-Time program for warm forming of Al and Mg sheet a) C-Frame Servo Press (Aida)

  9. Low RPM/ High TorqueMotor Drive 2/2 Servo-Press Drive Using Conventional Crank Mechanism Courtesy- Aida

  10. Hybrid Servo Press Block diagram of a hybrid servo press (ABB)

  11. Hybrid Servo Press Simplified 3D-view of a hybrid servo press, seen from above (ABB)

  12. Modern Stamping Lines UsingLarge Servo-Drive Presses • BMW- Leipzig & Regensburg (Germany) – SCHULER 2009 - 2500 ton servo-drive drawing press - 17 SPM • BMW – Leipzig, Regensburg and Shenyang (China) – SCHULER – 2012 – 7 tandem lines on order. • HONDA - Suzuka (Japan) – AIDA 2009 – 2500 ton tandem line – 18 SPM • Kamtek/COSMA – AIDA 2011 - 3,000 ton, 30 strokes/min • Honda-America – Ohio and Alabama - AIDA 2012 - 2,500 ton tandem lines • Hyundai – Korea – ROTEM 2012 – 1000 ton Tandem line • Others ?

  13. Schematic of Servo-press tandem line (Aida/Honda) 2500 ton/ 18 SPM (2009) Improved Formability Improved Productivity Energy-Saving ・Press-to-Press Loading Motion: System is optimized for each product. ・System with optimized press forming requirements for each product ・Die cushions have an energy regeneration system

  14. Servo-press tandem line (Schuler/BMW) 2500 ton/ 17 SPM (2009) • One drawing press + 5 presses for follow-up operations • Technical Data: • Total press force: 10,300 tons • Drawing press force: 2,500 tons • Total length of press line: 98 meters • Length o press: 34 meters • Strokes per minute: 17 • Source:BMWarchive.de • Source:Schulergroup.com

  15. Servo Tandem Line at Suzuka (Japan) Plant (Honda)

  16. Applications- Deep Drawing 1/3 (Courtesy- Schuler) • Comparison between the slide motions of an 1100 mechanical and servo drive press for identical slide velocity during forming [Bloom, 2008].

  17. Applications- Deep Drawing 2/3 (Courtesy- Schuler) • Decrease in cycle time by reducing the stroke length and operating the servo press in “pendular” mode (progressive die stamping, 200% increase in output) [Bloom, 2008]

  18. Applications- Deep Drawing 3/3 (Courtesy- Schuler) Decrease in cycle time as well as in impact speed using a servo press (150% increase in output) [Bloom, 2008]

  19. Side Panel Outer Deep Drawing Case Example (Honda)

  20. Applications- Blanking/ Ironing • Precision Formed Part a) partially blanked, b) finished blanked [Miyoshi, 2004 / Komatsu] • Slide motion used for partial and finish blanking [Miyoshi, 2004 / Komatsu]

  21. Applications- Reduction of Springback (Courtesy- Komatsu/ Hamamoto) Item : Eye glass frame Material : Titanium based Shape-memory Alloy Three processes had been required to control the springback. By multiple step motion, Three processes turned into single process. Multiple step motion

  22. Applications- Blanking/ Ironing Courtesy – Aida) IT IS POSSIBLE TO DIGITALLY SET THE OPTIMAL WORKING SPEED, THEREBY INCREASING DIE LIFE. Al STEPPED HOLE PIERCING (80% BURNISHED SHEAR FACE) SUS304 PIERCING A HOLE WITH A SMALLER DIAMETERTHAN THE MATERIAL THICKNESS(INCLINED HOLE PIERCING)

  23. Applications- Blanking/ Ironing (Courtesy – Aida) SINCE THE PRESS CAN BE RUN AT LOW SPEEDS, IT IS NOT NECESSARY TO SWITCH TO A LARGER CLASS PRESS TO FORM HARD-TO-DRAW MATERIAL. DRAW WRINKLES CAN BE AVOIDED BY SLOWING DOWN THE DRAWING SPEED. (SINCE WORKING ENERGY IS ALWAYS AVAILABLE, THE PRESS DOES NOT STOP EVEN AT INCHING SPEEDS.) WRINKLES CAN OCCUR WHEN THERE IS INSUFFICIENT PRESS RIGIDITY AND THE DRAWING SPEEDS ARE NOT OPTIMIZED.

  24. Applications- Auxiliary Operations (Courtesy – Aida) IT IS POSSIBLE TO SET THE OPTIMAL FORMING MOTION AND TIMING FOR SECONDARY PROCESSES. (STAKING AND ASSEMBLY) STAKING A PIN (∅3.6) IN A CHASSIS DURING A PROGRESSIVE FORMING OPERATION ASSEMBLY OPERATION OF A SQUARE NUT (M5)IN A BRACKET DURING A PROGRESSIVE FORMING OPERATION

  25. Applications- Warm Forming of Al, Ti, Mg, and SS Tool and process design guidelines to improve formability Power Source Balancer tank Main gear Capacitor Servomotor Drive Shaft Aida Servo Press (used in warm forming of Al, Mg and Ti sheet)

  26. Applications- Warm Forming of Al Preliminary results (Velocity range : 2.5-50mm/sec) AL 5754- O AL 5052-H32 Note : RT: Room temperature, LDR : Limit draw ratio Cup Diameter : 40mm

  27. Applications- Warm Forming of Mg and Ti Preliminary results (Velocity range : 5-50mm/sec) Mg AZ31-O Ti (Grade 1) Note : RT: Room temperature, LDR : Limit draw ratio Cup Diameter: 40mm

  28. Applications- Warm Forming of Mg Lap Top Case • Press slide motion used in warm forming processes (TDC - Top Dead Center, BDC – Bottom Dead Center) • Warm formed lap top case from Mg alloy • (Courtesy – AIDA)

  29. Servo-Hydraulic Cushion (Courtesy-Aida) Die Cushion Force (kN) Elimination of Pressure Surge in the Die Cushion

  30. Capabilities of the Self-Driven Hydraulic Servo Cushion pre-acceleration to reduce the impact speed between the die and blank holder variable pressure / force capability to control blank holder force/pressure during stroke prevention of momentary return of the cushion after BDC to avoid pressure on the top of the part

  31. Servo-Hydraulic Cushion (Courtesy-Aida) Power Regeneration: Approx. 70% Power Direction Motor Torque Direction Pump Rotation Direction Linear Scale S/M SM Pressure Sensor During Down Stroke, Cushion Pressure Generates Power Closed Hydraulic Circuit

  32. Advantages of Servo- Press Technology- Applications in Forming AHSS - • Major Challenges in Forming AHSS (DP, TRIP, TWIP) include: • lower formability (ductility) and higher probability of fracture • variations in mechanical properties form batch to batch • higher forming forces and high sheet/die interface pressures & temperatures • Excessive tool wear, rapid increase in down-force and large reverse tonnage • large springback due to large tensile strength

  33. Advantages of Servo- Press Technology- Applications in Forming AHSS - • Precise Ram Position (including dwell) and velocity control • allows for easier die set-up • prevents noise and shock when the ram is contacting the workpiece (hydraulic cushion with pre-acceleration) • improves formability and reduces fracture by reducing ram velocity during deformation (drawing, stretching and bending), improves die/sheet lubrication by reducing temperature increase at sheet/die interface • reduces shock loading and reverse tonnage in blanking, improves tool life

  34. Advantages of Servo- Press Technology- Applications in Forming AHSS - • Dwell at BDC and Pendulum Motion allows: • dwell at BDC and restriking quickly through pendulum motion before the formed material fully strain hardens, reduces springback (die design is still very important) • Adjustable Stroke Length (TDC to BDC): • provides flexibility so that in the same press, drawing, blanking and coining can be conducted with maximum productivity (high strokes/min)

  35. Advantages of Servo- Press Technology- Applications in Forming AHSS - • Ram Position/Velocity can be: • synchronized with automatic (or robotic) part transfer to increase strokes/min • adjusted to maximize strokes/min while maintaining lower ram velocity during forming stage

  36. Servo-Drive Press TechnologySummary / Outlook • Gap presses up to 150 ton are in production (15+ years) • Straight Side stamping presses up to 3000 ton are already built • Direct drive (high torque) motors and energy recovering cushions are used • High speed automotive stamping transfer presses (18 strokes/min)/ Schuler-BMW/ Aida-Honda and Cosma / Komatsu-Toyota & others • Novel tool design techniques for servo drive technology are being developed • Servo-drive presses will greatly contribute to improving the technology for forming AHSS and Al alloys

  37. Questions/Comments TaylanAltan, Professor and Director Center for Precision Forming (CPF) www.cpforming.org / www.ercnsm.org The Ohio State University, Columbus, OH Email: altan.1@osu.edu, Ph: (614) 292 5063 Source: Chapter 11 – Electro-mechanical Servo-Drive Presses in “Sheet Metal Forming, Fundamentals”, Vol. 1, by Altan/Tekkaya, ASM International, www.asminternational.org

More Related