Nowadays, many bending machines emphasize the pre bending function, so what is the pre bending function of bending machines? The rolling machine is a molding machine that continuously bends the sheet metal. When rolling the sheet metal, a regular symmetrical three roller rolling machine usually leaves a certain width of dead edges at both ends of the sheet metal. After being rolled into a cylinder, the pre bending function is to remove the dead edges and merge them into a cylinder. The workpiece produced by the rolling machine has many straight edges at both ends and needs to be welded before rolling, which takes time and reduces work efficiency. The problem can be solved by using a horizontally adjustable plate bending machine and an upper roller universal plate bending machine. The upper roller of the Yinli upper roller universal plate rolling machine can perform horizontal movement and pre bend the plate to eliminate straight edges, thereby improving work efficiency.