METHOD OF FORMING WHEEL DISCS Russian patent published in 1997 - IPC

FIELD: cold sheet forming, namely, production of wheel discs and other aperture parts by drawing or shaping. SUBSTANCE: method of forming wheel disc comprises steps of blanking sheet blank, drawing it, punching central and mounting holes and ventilation ports. Ventilation ports are punched by two stages. At first before drawing step only a part of port adjoining to central zone of disc is punched. It allows to receive uniform end edge of disc in zone of welding it with rim. After drawing step remaining part of port is punched in formed wall. Formed product has stable dimensions along its height in range of predetermined allowance values. EFFECT: metal economy due to decreased dimensions of blank, stability of disc size. 3 dwg