Tapered ferrite core, its production method and apparatus, and inductance device comprising it
A tapered ferrite core having a solid or hollow cylindrical shape with larger length than outer diameter, and comprising a ground taper portion in at least one end portion, the taper portion having ground streaks extending in the longitudinal direction of the ferrite core, can be formed by centerless-grinding a rotating ferrite core by a rotating grinder.
1. A tapered ferrite core having a solid or hollow cylindrical shape with larger length than outer diameter;
said ferrite core having a ground taper portion in at least one end portion; and
said taper portion having ground streaks extending in the longitudinal direction of the ferrite core.
2. The tapered ferrite core according to claim 1 , wherein said ferrite core has no defects due to granule boundaries.
3. The tapered ferrite core according to claim 1 , wherein said taper portion is constituted by pluralities of worked surfaces having different tapering ratios.
4. A tapered ferrite core having a solid or hollow cylindrical shape with larger length than outer diameter;
said ferrite core having a ground taper portion in at least one end portion; and
said taper portion having ground streaks extending in the longitudinal direction of the ferrite core and radially isotropically extending from a center axis of the ferrite core.