The Servo Rotary Draw Tube Bending Machine combines multi-axis electric servo drives with heavy-duty hydraulic clamping for high-precision metal tube forming. Equipped with servo control across tube feeding, plane rotation, bending C-axis, and pressure die movement, the system maintains consistent bend angles within small margin limits. The hybrid structure delivers constant clamping torque while minimizing hydraulic oil thermal expansion, ensuring dimensional accuracy during multi-shift industrial production.
Key Features
Multi-Axis Electric Drive: Absolute encoder servo motors control feeding, spatial rotation, bending angle, and pressure die positioning.
Hybrid Power Distribution: Electric servos drive spatial positioning while hydraulic cylinders supply clamping and mandrel extraction forces.
Springback Angle Calculation: Control software adjusts bend arm rotation angles based on batch material yield strength inputs.
Synchronized Pressure Die Motion: Servo-assisted pressure die tracks material movement to control wall thinning on tight centerline radii.
Interference Detection: Integrated software simulates part geometry relative to machine clearance zones prior to cycle execution.
Power Management: Servo systems consume full current exclusively during movement cycles, reducing overall power requirements.
Technical Specifications
|
Parameter |
Unit |
Specification Value |
|
Max Outer Tube Diameter |
mm |
89 |
|
Max Tube Wall Thickness |
mm |
4.5 |
|
Max Center Line Radius |
mm |
250 |
|
Number of Servo Axis |
- |
4 |
|
Bending Angle Precision |
deg |
0.1 |
|
Tube Rotation Precision |
deg |
0.1 |
|
Axial Feeding Precision |
mm |
0.1 |
|
Max Bending Angle |
deg |
190 |
|
Max Feeding Speed |
mm/s |
1000 |
|
Max Rotation Speed |
deg/s |
260 |
|
Operating System |
- |
Industrial PC Touchscreen CNC |
|
Hydraulic System Pressure |
MPa |
15 |
How It Works
Rotary draw bending secures the leading section of the tube against a rotary bend die. As the die rotates, the tube advances across an internal mandrel and wiper assembly.
Axial Positioning:
The servo carriage moves the tube to the length coordinate and rotates it to the required spatial plane angle.
Hydraulic Locking:
Hydraulic cylinders engage the clamp die against the main bend die and secure the pressure die block.
Draw Bending:
The main servo motor rotates the bend arm, drawing material around the bend die while the pressure die matches carriage travel speed.
Mandrel Release:
The internal flexible mandrel retracts via hydraulic cylinder before final bend completion, releasing clamping force for part removal.
Applications of Servo Rotary Draw Tube Bending Machine
Automotive Exhaust Systems: Precision forming of stainless steel manifolds, tailpipes, and fluid lines.
HVAC Heat Exchangers: Uniform copper and aluminum pipe bending for commercial refrigeration headers.
Aerospace Tubing: Thin-wall aluminum and alloy tube shaping for liquid transport lines.
Structural Metal Frames: Uniform radius bending on steel round, square, and oval tubing for furniture and chassis structures.
Pressure Vessels: Heavy-wall carbon steel tube processing for power generation heat transfer units.
Machine Configuration
Machine Bed Structure: Stress-relieved, heavy welded steel frame designed to resist axial torsion under continuous mechanical load.
Servo Drive Motors: High-resolution AC servo motors paired with low-backlash planetary gear reducers.
Hydraulic Unit: Variable-displacement pump assembly integrated with an automated air-cooling system.
Linear Travel Guides: Hardened, precision-ground linear motion rails equipped with automatic lubrication distribution blocks.
Electrical Cabinet: Sealed enclosure with automated temperature control housing industrial control hardware.
Bending Capability
|
Material Grade |
Diameter Range |
Wall to Diameter Ratio |
Min Bend Radius |
|
Carbon Steel |
12 mm to 89 mm |
Above 1.5 percent |
1.0 Outer Diameter |
|
Stainless Steel |
12 mm to 76 mm |
Above 2.0 percent |
1.15 Outer Diameter |
|
Aluminum Alloy |
15 mm to 89 mm |
Above 2.5 percent |
1.2 Outer Diameter |
|
Copper Tubing |
10 mm to 65 mm |
Above 1.5 percent |
1.0 Outer Diameter |
Optional Equipment
Internal Mandrel Lubrication System: Direct oil injection through internal mandrel fluid passages during bending cycles.
Wiper Die Support Seat: Adjustable mechanical mounting fixture engineered to maintain wiper alignment.
Weld Seam Alignment Sensor: Optical sensor detects longitudinal weld lines to position seams away from high-tension bend zones.
Automation Interface: Digital input output modules configured for robotic material loading and unloading arms.
Safety Light Curtains: Multi-beam optical safety sensors positioned around the bend arm work envelope.
Tooling and Dies
Bend Die:
Machined tool steel hardened to HRC 58-62 for long operational life.
01
Clamp Die:
Precision-bored clamping surface designed to grip raw tube stock without surface displacement.
02
Pressure Die:
Heavy-duty tool block guiding material into the bend die face.
03
Wiper Die:
Nitrided steel or bronze alloy insert shaped to prevent material wrinkling along the inner bend radius.
04
Mandrel Assembly:
Multi-ball flexible mandrel units manufactured from hardened alloy steel or copper-based bronze.
05
Manufacturing Standards and Quality
Tooling Inspection: Complete Coordinate Measuring Machine verification for all custom die contours prior to delivery.
Thermal Treatment: Machine frame structures undergo thermal stress relief annealing to preserve structural alignment.
Electrical Design: System wiring complies with standard industrial electrical safety protocols.
Factory Acceptance: Full operational cycle testing and optical laser measurement performed on completed equipment assemblies.
FAQ
Q: What is the mechanical distinction between a hybrid servo-hydraulic machine and a fully electric machine?
A: A hybrid system uses electric servo motors for spatial movements including feeding, rotation, and bending angles, while relying on hydraulic cylinders for clamping forces and mandrel extraction. A fully electric machine replaces hydraulic actuators with electric ball screws. Hybrid systems provide structural force and cost balance for medium to heavy wall thicknesses.
Q: How does the machine handle tight bends down to 1.0 times the outer tube diameter?
A: Bending to a radius equal to tube outer diameter requires a multi-ball flexible mandrel, a fitted wiper die, and a servo-assisted pressure die working together to maintain tube roundness and limit wall thinning.
Q: How does the control system handle springback variations between raw material batches?
A: Operators can enter material yield values or perform a single test bend. The control software calculates material springback and adjusts C-axis rotation parameters automatically.
Q: What digital file formats can be loaded into the control software?
A: The operating interface reads STEP and IGES files directly. The software parses centerline vectors, outer diameter measurements, wall thickness values, and bend coordinates automatically.
Q: What is the process for changing tooling between different production batches?
A: Tooling components utilize quick-change mounting keyways. Operators swap the bend die, clamp die, wiper, and pressure die, select the corresponding saved profile in the control interface, and resume production within fifteen minutes.