Method for forming large-size curved thin-walled metal skin

Abstract

A method for forming a large-size curved thin-walled metal skin is disclosed, wherein the position and size characteristics of stiffeners on a curved panel is extracted; the thickness of the curved panel and the thin-walled skin after assembly is assumed to be m, and a forming surface of the punch is offset outwards along a normal line by the thickness m to obtain the characteristics of the inner surface of a female die; the number of the discrete support moulds is set to be the same as the number n of the stiffeners based on the size and distribution of the stiffeners on the curved panel; and the punch and the female die combined with the discrete support moulds are used to carry out stamping of a curved thin-walled slab to obtain a required thin-walled skin component.

1 . A method for forming a large-size curved thin-walled metal skin, comprising the following steps:
 step 1: extracting the position and size characteristics of stiffeners on a curved panel according to the assembly relationship between the curved panel and a thin-walled skin;   step 2: assuming that the thickness of the curved panel and the thin-walled skin after assembly is m, determining the size of a forming punch based on the shape and size of the curved panel, and offsetting a forming surface of the punch outwards along a normal line by the thickness m based on the size of the forming surface to obtain the characteristics of the inner surface of a female die;   step 3: determining the size of discrete support moulds to be the same as that of the curved panel according to the thickness of the curved panel, and determining forming surfaces of the discrete support moulds based on the inner surface of the forming thin-walled skin;   step 4: setting the number of the discrete support moulds to be the same as the number n of the stiffeners based on the size and distribution of the stiffeners on the curved panel, and the positions of the discrete support moulds on the punch are consistent with the positions of the stiffeners on the curved panel;   step 5: processing and manufacturing the punch, the female die and n discrete support moulds according to step 2 and step 3;   step 6: fixing the n discrete support moulds on the punch according to step 4, and the relevant positions for connecting the discrete support moulds are corresponding to the positions of the stiffeners on the curved panel during assembly; and   step 7: using the punch and the female die combined with the discrete support moulds to carry out stamping of a curved thin-walled slab to obtain a required thin-walled skin component.