| 摘要 |
PROBLEM TO BE SOLVED: To form a magnetic-pole group in which a plurality of magnetic poles are magnetized on the circumferential surface of an object to be magnetized having non- magnetized end, and a magnetic powder can be attracted uniformly thereon. SOLUTION: A magnetizing head is arranged in a manner to be in contact with or close to the circumferential surface of an object to be magnetized so that two magnetizing poles are opposite to each other in the circumferential direction of the object to be magnetized, and magnetic poles are magnetized one by one by the width of the magnetizing head so that they continue in the widthwise direction through plural magnetizing operations. A joint section at the time of a first magnetization is provided at a position displaced from the joint section of adjoining magnetic pole in the widthwise direction. In concrete, while the object to be magnetized is rotated in the circumferential direction and the magnetizing head is driven at a constant speed in the widthwise direction, a cyclic magnetizing current is applied for magnetization. In this case, the magnetization in the circumferential direction is applied at an interval in distance N times (integer of 2 or more) the final magnetization interval, and the magnetizing head moves one Nth of its width (truck width) during one turn of the object to be magnetized in the widthwise direction. Then, after second turn, the previously magnetized between-magnetic poles are magnetized. |
