| 摘要 |
<p>PURPOSE:To omit the gate cutting process of a green body, and simplify the inspection process of trench depth after sintering and grinding by providing the surface on which coil trenches are not formed with a plurality of pin-gates, and arranging the pin gates so as to have symmetry with respect to the center of a circular ring, at recessed positions with respect to the flat surface. CONSTITUTION:On the upper surface of a green body 11 for core main body, two coil-trenches 12 of concentric circle type are arranged. Leading-out trenches 13 are formed in radial direction, in order to connect each of the trenches 12 with the external peripheral part. On the surface 14, of the green body 11 for core main body, on which the trenches are not formed, pin-gates 16 are arranged so as to be symmetric with respect to the center of a circular ring, at recessed positions 15 with respect to the surface. The green body 11 for core main body is molded as follows; mixture of sintering ferrite and binder is injection molded, melted material is filled in a metal mold to form a first spool 20, a runner 21, and a second spool 22, and injected into a forming part of the green body 11 for core main body, from the pin-gates 16 forming the tip part of the second spool. Thereby, the gate cut process at the time of degreasing and sintering of the green body 11 for core main body is omitted, and the inspection process of the trench depth of a grounded body can be simplified.</p> |
