Accurate machining method for large-diameter aluminum alloy non-uniform section frame ring

The invention provides an accurate machining method for a large-diameter aluminum alloy non-uniform section frame ring. The method includes the main machining steps that S1, a large-diameter aluminum alloy non-uniform section frame ring piece is tightly pressed onto a clamping device from top to bottom; S2, compression is performed at the top of a mold so that a plurality of long pressing plates can overhang out of the inner side to tightly press a part, and the outer circle of the frame ring piece is machined; S3, the long pressing plates are dismantled, a plurality of upper pressing plates are tightly pressed at the top of the mold, and the fit clearance and form and location tolerance between the clamping device and the part are detected; and S4, a gamma groove in the part is machined through a layered cutting method. The main steps comprise rough machining, semi-finish machining and finish machining, and accordingly accurate machining of the frame ring can be completed. By the adoption of the method, wall