METHOD FOR MAKING DIFFERENT-THICKNESS SHEET PRODUCTS Russian patent published in 2003 - IPC

FIELD: plastic metal working, namely manufacture of panels, hatches and other sheet parts with thickened edges while taking into account their lowered strength in zones of thermic influences caused by welding of adjacent parts. SUBSTANCE: method for making different-thickness sheet articles comprises steps of creating shearing deformation in direction of force action upon blank by means of flat strikers in flat sheet constant-thickness blank; simultaneously preliminarily forming flat sheet blank to hollow semifinished product with portion in the form of truncated cone; placing semifinished product into pack between two shaping members having the same height in axial direction, outer diameter D_o and working surfaces (inside pack) engaging with respective surfaces of semifinished product; imparting to mutually opposite surfaces of semifinished products for making round (in plan view) articles form of truncated cones; providing constant total height in axial direction of pack defined by shaping members and semifinished product equal to (0.2 - 0.3)D_o; upsetting prepared pack in container with diameter D_o while transforming initial thickness of semifinished product to thickened portion of article at forming transition thickened zones. EFFECT: prevention of defects of well known similar process for making different-thickness sheets and blanks, enhanced factor of metal usage, lowered labor consumption at working articles. 5 dwg