A method for manufacturing a detection gear for a rotation angle detection device, a rotation angle detection device, and a detection gear for a rotation angle detection device.

摘要

PROBLEM TO BE SOLVED: To accurately fix a cylindrical magnet to a gear body in a detection gear used in a rotation angle detection device, and to prevent a decrease in magnetic force due to a recess or a through hole for positioning. A detection gear 1 comprises a magnet 2 for detecting a rotation angle of the detection gear 1 by a magnetic sensor, and a resin gear body 3 that rotates integrally with the magnet 2. The shape of the magnet 1 is cylindrical. The gear body 3 includes a base portion 4 having a gear 4A that meshes with the main gear, and a magnet holding portion 5 that holds the magnet 2. The magnet holding portion 5 has three or more notched portions 5A in the circumferential direction facing the outer peripheral surface 2C of the magnet 2. [Selection diagram] Fig. 1