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Stretch Forming Machine for Bumper Beam

stretch forming maching

PBF Stretch Forming Machine for Bumper Beams is a specialized manufacturing tool designed for shaping and forming the structural components of automotive bumpers. PBF stretch bending machine utilizes a stretching process to shape metal sheets into the desired contours and profiles required for bumper beams.

The PBF Stretch Forming Machine‘s control system, often CNC-based, ensures precise and repeatable forming according to design specifications. It accommodates various sizes and materials used in bumper beam production, offering flexibility in manufacturing. The stretch forming process enhances the structural integrity and design precision of bumper beams, crucial components for vehicle safety.

Aluminum Bumper Beam Stretch Forming Process

Aluminum bumper beams are structural components in cars crafted from aluminum alloys. Vehicles employ aluminum bumper beams for several reasons, primarily to achieve a balance between strength and weight savings. The lightweight nature of aluminum aids in enhancing fuel efficiency and overall vehicle performance. The use of aluminum in bumper beams contributes to the reduction of the vehicle’s overall weight, supporting automakers’ efforts to meet fuel efficiency standards and improve handling.

Key features of aluminum bumper beams include their excellent strength-to-weight ratio, corrosion resistance, and malleability, allowing for versatile design options. The material’s ability to absorb and dissipate impact energy during collisions enhances passenger safety. Additionally, aluminum’s recyclability aligns with sustainability goals in the automotive industry.

Overall, aluminum bumper beams represent a strategic choice in vehicle design, offering a combination of structural integrity, weight reduction, and environmental sustainability. Their utilization aligns with the broader industry trend toward lightweight materials for improved efficiency and safety.

Challenges in Bending Aluminum Alloy Bumper Beams

  • Uncontrollable springback;
  • Deformation of the cross-section after bending;
  • Stability of curvature fit;
  • Uncertainty in where to start and difficulty in finding suitable theoretical support.

Innovation in the Production Process of Bumper Beams

Numerical Control Stretch Forming

  • Adaptation: Large-scale, diverse, multi-curved segments, angles ranging from 10º to 85º
  • Efficiency: 25-45 seconds per piece;
  • Qualification Rate: 99.9%;
  • Profile Deviation: 0.5-1mm (Key Reference Points: ±0.2mm);
  • Process: T4 aluminum profiles → Stretch Bending → Aging to T6 → CNC Machining
  • Operation: No need for skilled technical workers, automatic generation of bending trajectories;
  • Procedure: Import graphics for automatic programming and generation of production data;

Case Study

  • Material: 7T09 series aluminum alloy
  • Yield Strength: 350±30Mpa
  • Cross-sectional Area: 1330.78mm^2
  • Bending Material State: T4
  • Bending Forming Force: 65.5T
Stretch Forming Machine for Bumper Beam

Image Description

A: Tightening blocks on both sides to ensure that the straight segment is not bent;
B: Middle tightening block to ensure proper filling of the core rod and prevent the straight segment from bending during the bending process;
C: Positioning hole;
D: Filling, ensuring no wrinkles after stretching and forming;
E: Must be filled before bending, or else it may collapse. The equipment comes with filling and extraction functions.


T4 aluminum profiles → Bending → Aging to T6 → CNC Machining

  • Length of straight segments at the ends: <80, groove depth 0.3, consistent clamping marks, no sliding teeth;
  • Bending radius: ±1mm, straightness: ±1mm;
  • Production cycle: 35-45s/piece;
  • Qualification rate: ≥99.9%; CPK: >=1.33.

Stretch Forming Machine for Bumper Beam

  • Maximum tensile bending capacity: >=55T
  • Clamp spacing: 600-2000mm
  • Flat layout (estimated): 8500*9000mm
  • Installed power: 100KW


  • Maximum Tensile Force: When both swing arms are at the 0° position and the stretching cylinder is at the furthest distance from the mold base, the maximum tensile force is 55 tons.
  • Tensile Force Control Precision: Control precision: ±0.001 ton
    Variation in tensile force during wrapping: ±0.001 ton
  • Clamp Spacing: Range: 600-2000mm
  • Flat Layout (Estimated): Dimensions: 8500*9000mm
  • Installed Power: Power: 100KW
  • Min Distance Between Front End Faces of Jaws: When both swing arms are at the 0° position and the stretching cylinder is at the closest distance to the mold, the minimum distance is 600mm.
  • Max Distance Between Front End Faces of Jaws: When both swing arms are at the 0° position and the stretching cylinder is at the furthest distance from the mold, the maximum distance is 2000mm.
  • Stretching Cylinder Horizontal Height: When the stretching cylinder is in a horizontal position and at the lowest position, the height of the jaws’ centerline from the mold base plane is 450mm.

Stretching Cylinder Parameters

  • Diameter: 200mm
  • Stroke: 600mm
  • Control precision: ±0.03mm
  • Repeat precision: ±0.03mm
  • Stretching speed: 1-70mm/s, infinitely adjustable.

Bending Cylinder Parameters

  • Diameter: 180mm
  • Ejecting stroke: 1200mm
  • Control precision: ±0.03mm
  • Repeat precision: ±0.03mm
  • Ejecting speed: 1-90mm/s, infinitely adjustable.

Clamping Cylinder Parameters

  • Diameter: 150mm
  • Clamping stroke: 80mm
  • Control precision: ±0.03mm
  • Repeat precision: ±0.03mm
  • Clamping speed: 1-70mm/s, infinitely adjustable.

Core Pulling Oil Cylinder Parameters

  • Diameter: 80mm
  • Core pulling stroke: 800mm
  • Control precision: ±0.03mm
  • Repeat precision: ±0.03mm
  • Clamping speed: 1-70mm/s, infinitely adjustable.

Collision Prevention Beam Parameters

  • Bend radius above R1800
  • Cycle time: 35 seconds/piece (non-core pulling), 55 seconds/piece (core pulling required).

Stretching Cylinder Horizontal Swing

  • Swing angle: +50°/0°
  • Free swinging, automatic reset of the cylinder.

Mold Base Dimensions

Dimensions: 1500mmx1160mmx100mm.

Hydraulic System Design Pressure

  • Pressure level: 21MPa
  • Oil tank equipped with heating and cooling devices.

Oil Cylinder Limitation and Position Measurement

Both ends of each oil cylinder have limit switches (Omron proximity switches), and position measurement uses encoders.

Electrical Control Main Components

  • Main components such as PLC are from Mitsubishi.
  • Main hydraulic components are from YUKEN.

Electrical Control System Spare Interface and Space

  • Equipment weight (including mold, hydraulic, and oil cooling system): 20 tons.
  • The electrical control system has a 5% spare interface, and the control cabinet has a 15% spare space.
Stretch Forming Machine for Bumper Beam
Stretch Forming Machine for Bumper Beam
Aluminum Bumper Beam Stretch Forming Process