Pipe-bending machine technology is widely used in my country across sectors such as power infrastructure, road and railway construction, boiler and bridge manufacturing, shipbuilding, furniture, home appliances, and interior decoration; the process itself continues to evolve alongside technological advancements. These machines are commonplace and essential in industrial processing. This article outlines the characteristics and advantages of various types of pipe-bending machines, such as CNC, fully automatic, and hydraulic models.

In terms of machine design, the bending arm and the main bending spindle are integrated into a single unit, the bending die shaft is interchangeable, and the clamping die moves vertically; this rational structure enhances the mechanical strength of the assembly while simplifying the overall design and electrical circuitry. When feeding the material for the final bend, the carriage might collide with the pressure die; to prevent this, the "interference zone" function is employed using the following sequence: pressure die retracts → carriage continues to feed → bending arm returns → Plane of Bend (POB) rotation → clamping die engages → collet releases and carriage exits the interference zone → pressure die engages → pipe bending proceeds. This approach prevents collisions between the carriage and the pressure die—ensuring the successful completion of the final bend—while minimizing material waste at the clamping end and reducing overall production costs. The bending head can move laterally along guide rails, a feature necessary for aligning the bending die groove with the machine's centerline after a die change; this method is simpler and more convenient than adjusting the machine's centerline via the bed rails or tailstock. During the bending process, the carriage acts as a load, pulled forward by the pipe; to improve bending quality, prevent excessive wall thinning in the bend zone, and reduce springback, a booster mechanism has been added. During bending, the pressure die not only clamps the pipe but is also pushed forward by the booster force, creating a lateral thrust that assists the bending process.

After completing the linear feed movement (DBB), the carriage is pulled forward by the pipe during the actual bending operation. This eliminates the need for "positive thrust," thereby resolving the issue of synchronizing the carriage with the bending speed and removing the DC motor negative feedback system previously required to generate that thrust; consequently, the electrical circuitry is simplified. However, since positive thrust facilitates the bending process—and is particularly essential when bending large-diameter pipes—the VB pipe bending machine incorporates an auxiliary pushing device.