The fully automatic CNC pipe bending machine consists of three main parts: the mechanical section, hydraulic system, and control system (microcontroller, PLC, or PC).

The mechanical section mainly includes the pipe clamping device, bending drive device, boosting device, bed, and bending die fixing device. The CNC pipe bending machine utilizes a three-coordinate point control system, where the bending of the pipe is controlled through bending motion commands (NC instructions) that manage the movement of the three axes. The digital code information includes YBC data programs or vector coordinate point programs, bending speed, clamping force of the pressure blocks, and rebound amount.

Thus, the control system focuses on the Y, B, C, and X axes for digital control:

① Feeding Axis (Y-axis): The main control parameters are displacement, feed speed, and acceleration. The Y-axis movement refers to the linear reciprocating motion of the feeding trolley along the bed, driven by the machine's AC servo motor that engages with gears and racks. Motion accuracy is achieved through a photoelectric encoder and speed sensor that provide displacement and speed signals to the computer for closed-loop control.

②Rotating Axis (B-axis): This axis controls the rotation angle, angular speed, and angular acceleration. It mainly utilizes backlash-free gears as feedback signals for closed-loop control, allowing the pipe blank to achieve spatial rotation perpendicular to the Y direction.

③Bending Axis (C-axis): Control parameters include bending force, displacement, speed, and working acceleration. A hydraulic cylinder drives a chain system to rotate the bending arm, with the bending and return of the arm precisely controlled by the electro-hydraulic servo system. Additionally, adjustments to the axis perpendicular to the Y-C plane (X-axis) also require control of displacement, adjustment speed, and acceleration.