Method for controlling wall thickness difference of aluminum alloy backward extrusion aluminum pipe

The invention discloses an aluminum alloy backward extrusion aluminum pipe wall thickness difference control method. The method comprises the steps that S1, a blank with a target shape and a target size is obtained; s2, an assembly gap between a backward extrusion punch and a backward extrusion rod is adjusted, and it is guaranteed that the unilateral gap between the backward extrusion punch and the backward extrusion rod is smaller than or equal to 0.2 mm; s3, a gap between the backward extrusion punch and the backward extrusion cylinder is detected through a measuring tool; and S4, the inner wall of the backward extrusion cylinder is evenly coated with a lubricating agent, backward extrusion machining is conducted on the blank, and a finished pipe product is obtained. According to the method provided by the invention, the assembling gap between the backward extrusion punch and the backward extrusion rod is adjusted, the gap between the backward extrusion punch and the backward extrusion cylinder is detected