HSR High Speed Bullet Train Rail Stretch Forming Machine for high speed train rail system bending, Specialize in tight tolerances and demanding specifications.
Bullet Train CNC Stretch Forming Machine
After the bending, due to the material’s serious asymmetry in the width direction, the rebound will be unbalanced after the bending, and the distortion flatness of the two ends will not meet the requirements after forming.
Solution: A punches the ribs before punching, then bends, repairs and polishes.
The bending deformation of the B-bend male and female mold roots is pre-deformed. Process validation experiment.
After the bending, due to the large hardness range of the material, the rebound of the product is large, and the curvature of the product is poor.
At the same time, it will interact with the outer arc of the lower process.
Solution: A strictly control the extrusion hardness, so that the hardness changes within 2 degrees of Vickers hardness.
B hardness range is classified by grade. Every two degrees and one level, generally only need 2 levels, and individual incoming materials will exceed the two levels. Then open a set of molds at each level to deal with different hardness ranges.
C. The same batch of material is finished immediately. Don’t wait for the next batch to be recycled.
Checking: Panel fixture（laser cutting，observe the arc is tangent or not ）
Notch（CNC mill the complete groove, or obtain key point（3d)), special fixture.
Quantity/ efficiency 1、High quality, large quantity, such as automotive parts, 40 seconds / piece, stretch bending, otherwise roll bending. 2、More than 2 times by roller bending, qualified rate guaranteed over 90%, otherwise below 40%；
Qualified rate Roller bending: 2 times or more forming times, more than 85%; The rest 15% can be simply corrected; all saying that qualified rate more than 90% by once time deformation is deceptive, up to 50% (In roller bending there are high requirements for raw material, temperature, equipment and so on) .Stretch bending qualified rate can reach more than 99%, and the quality is higher.
Correction Regarding to sampling or small production, shall choose roller bending，manual correction is one of the core processes (3D can not be corrected)
Checking plane Detect inner arc or outer arc ? If outer arc stretching, internal arc will shrink or unchanged, the material must be deformed, the checking standard can only based on key point or key surface