| 摘要 |
PURPOSE:To obtain extremely stable magnetic exhange characteristics, by joining plural plate-shaped magnetic bodies together, forming a cut at the outer circumference part of at least one plate-shaped magnetic body, and expanding the cut and arranging an expanding member for pressing front gap surfaces against each other. CONSTITUTION:Core blocks 10 and 11 having tapered cuts 18 and 19 are joined together by laser welding in a usual way. The thermal expansion coefficient of the expanding member 20 inserted in the cuts 18 and 19 is less than those of the core blocks 10 and 11 in a heat treatment, so the expanding member 20 is held in the cuts 18 and 19 in a tight fit state at room temperature and also expands the cuts 18 and 19 to press the front gap surfaces 8 and 9 against each other, so that gap length precision and track abutting precision are much more stabler than usual even during an actual contact run on a tape. |
