| 摘要 |
PURPOSE: To form a strong magnetic field in a molding space by so forming rare earth element magnets at both side positions of an iron yoke that the poles opposed to the yoke become the same polarity as the pole present on the yoke surface excited by an electromagnet, and disposing the magnets in close contact. CONSTITUTION: Rare earth element magnets Q are disposed in close contact at both side positions of an iron yoke 12 for forming a present image pole. The present image pole is the pole required for strongest magnetic force of a plurality of poles of a magnet roll. As the magnets Q, Sm-Co or Nd-Fe-B alloys can be used, and in addition, rare earth element magnets including rare earth elements such as Y, Pr, La, Ce, Gd, Pm, Eu, Lu, Dy, Tb, Ho can be used. The magnets Q having a residual magnetic flux density (Br) of 8000 gauss and a coercive force (iHc) of 12000 oersted is used. |
