| 摘要 |
A tone wheel constituting a rotation detection magnetic encoder in combination with a magnetic sensor fixed onto a stationary side member, the tone wheel comprising a metal reinforcing ring fitted in a rotary side member and a circular multipolar magnet fixed to the metal reinforcing ring. the circular multipolar magnet is made of a plastic magnet of a circular resin molded product which contains a magnetic powder therein and is magnetized with a number of S and N poles alternatively along its circumference; the circular multipolar magnet is fixed to a surface of the metal reinforcing ring opposed to the magnetic sensor with an adhesive; and a restraint portion is provided at a part of the portion wherein the circular multipolar magnet is fixed to the metal reinforcing ring, thereby fixation of the circular multipolar magnet to the metal reinforcing ring is reinforced and depart of the circular multipolar magnet from the metal reinforcing ring is prevented. |
