Avoiding Pipe Bending Defects: Solutions for Pipe Wrinkling and Deformation in Hydraulic Pipe Bending Machine Processing

Pipe wrinkling and cross-sectional deformation are common defects, which can be resolved through process optimization:

Main Causes of Wrinkling and Countermeasures

Excessively small bending radius: When R ＜ 1.5D, compulsorily adopt the combination of a mandrel and an anti-wrinkling die.

Incorrect mandrel position: Set the advance amount to 10% of the pipe diameter (e.g., Φ40 pipe = 4mm).

Excessively high speed: Adjust the hydraulic valve to reduce the bending speed to below 3mm/s.

Control of Elliptical Deformation
Filling method: When bending copper pipes, fill the interior with fine sand (particle size ≤ 1mm) and seal both ends.
Die compensation: Use a dedicated die blank with an elliptical correction groove.
Pressure adjustment: Reduce the pressure of the clamping die to the minimum value that prevents pipe slippage (usually ＜ 10MPa).

Process Verification Process:
Test bending → Sectioning and measuring ovality (standard: minor axis/major axis ≥ 0.85) → Adjust parameters → Mass production