| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method for a yoke that is combined with a magnet or the like of a speaker used for various acoustic units to form a magnetic circuit and whose magnetic efficiency is enhanced. SOLUTION: In the manufacturing method for a yoke of this invention, a piece 1 with a prescribed outer diameter is punched from a plate made of a magnetic metallic material with a prescribed thickness, drawing is applied to the piece 1, a recess 4b is formed by pressing to the center part of a bottom side, the recess 4b is made thin, especially thinning by drawing the thick thickness of a bottom outer circumferential part 4c is presented so as to prevent the magnetic saturation by the outer circumferential part 4c.
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