METHOD OF FORGING POLAR WHEEL FOR MOTOR VEHICLE ALTERNATOR, COLD FORGING MATRIX AND POLAR WHEEL OBTAINED THEREBY

摘要

The method according to the invention involves a hot-forging step and a cold-forging step that occurs after the hot-forging step. A polar wheel (10, 11) incorporating a plurality of finite chamfers (102) formed on exterior parts of the polar teeth (10g, 11g) is produced during the hot-forging step. According to the invention, the cold-forging step involves substeps of placing the polar wheel in a die, cold die-stamping the polar wheel with a first and a second blow in the axial direction of the polar wheel, upsetting material onto interior parts of the polar teeth (10g, 11g) so as to form magnet-housing grooves (100) and magnet lips (101).