ELECTRON BEAM ADJUSTMENT DEVICE, MAGNET USED FOR IT AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To increase the number of welding parts by providing a cavity with a plurality of gates, decrease density unevenness of resin composition in the same magnet mold product, and decrease magnetizing variations. SOLUTION: A ring-shaped magnet is used provided with magnetic poles at places other than welded parts of a bonded magnet molded product injection molded with the use of an injection molding mold equipped with a plurality of gates so as to get a plurality of welding parts made of a resin composition mixed in a binder consisting of magnetic particles, resin, a fire retardant agent, and an additive.