抄録
This research presents three-dimensional (3D) tube forming processes using a new hydraulic bending machine. The proposed bending machine uses a new method. When tube is fed into the fixed and active dies, it is bent by shifting the relative position of the active die. The bending shapes are controlled by the relative distance and orientation between the mobile die and the fixed die, and the length of the fed tube. The active die movement is controlled by six-degrees-of-freedom parallel kinematics with a hydraulic servo drive. This forming process has a big advantage. The change of the expected bending shape will require no change in the tooling system, but only a new control program for the motion of the active die and the length of the fed tube. Practical applications show that the bending machine can be applied to universal designed products with a 3D profile. Based on these bending processes, we also proposed a procedure to determine the controlling parameters of 3D tube forming processes. Experimental results show that the controlling parameters can be applied to square pipes with a helix shape. Until now this spiral process has been difficult to achieve using a conventional bending machine.
