| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method for commutators, wherein a commutator are easily manufactured and it is so structured that a commutator piece is hardly broken away from an insulator. SOLUTION: The manufacturing method comprises the steps of: rounding a plate material T having multiple protrusions 11 arranged in parallel into a cylindrical shape; filling the inner circumferential side of the plate material T with liquid resin; and, after the resin is cured, cutting a portion A to be undercut in the cylindrical plate material T to form multiple commutator pieces from the plate material T. The method further comprises the steps of: before the rounding step, pressing the plate material with a splitting punch 21 to form split grooves 12 in the protrusions 11 and obtain pairs of split protrusions 9 formed by splitting the protrusions 11 in the direction of their parallel arrangement; and thereafter pressing the plate material with an oblique groove forming punch to form oblique grooves inclined from the parallel direction in the split protrusions 9 and simultaneously form protruded portions 14 protruded in the direction orthogonal to the direction of the protrusion of the split protrusions. COPYRIGHT: (C)2009,JPO&INPIT
|
