JPS6464204A - Magnet roller - Google Patents

Abstract

PURPOSE:To increase magnetic force by orientating ferromagnetic substance powder in a molded form so as to be converged along a straight line tying an N pole and an S pole at the central section of the molded form between N poles and S poles for each magnetic substance and toward the central sections of the magnetic peaks of the N poles and the S poles in sections near the N poles and the S poles. CONSTITUTION:Ferromagnetic substance powder is orientated so as to converged in approximately parallel along lines tying N poles and S poles at the central section of a molded form and toward the central sections of the magnetic peaks of the N poles and the S poles in sections near the N poles and the S poles among the N poles and S poles of magnetic pairs. When resin magnet materials (ferromagnetic substance powder and a binder) melted under the state in which magnetic flux shapes a closed loop are injected into a cavity 14, magnetic powder 15 is orientated, following the flow 13 of the line of magnetic force. Since the line of magnetic force spreads in the cavity 14 and is converged in a magnetic pole section, magnetic powder 15 is also orientated under the state in which it is converged in the magnetic pole section. Magnetic powder 15 in the molded form is used effectively owing to such orientation, and the line of magnetic force is concentrated at the desired position of the molded form, thus acquiring a magnet roller having high surface magnetic flux density and strong magnetic force.