MAGNETIC ENCODER AND MANUFACTURING METHOD THEREOF

• Main Authors: SAITOH MITSURU, TAKI MASAYUKI
• Format: Patent
• Language: English
• Published: 10.12.2015
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVEREDIN A SINGLE OTHER SUBCLASS; MEASURING; MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; PHYSICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TARIFF METERING APPARATUS; TESTING; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

Provided is a magnetic encoder in which the outer diameter of an annular plastic magnet is increased to widen a magnetic force stable region, and a manufacturing method thereof. An axial-type magnetic encoder 1 includes: an annular fixing member 2 that has a cylindrical part 2A attached to a rotating body and an inward flange part 2B extended radially inward from an end edge of the cylindrical part 2A and is fabricated by press molding; and an annular plastic magnet 3 that is attached by injection molding to a sensor-opposed surface of the annular fixing member 2. The magnetic encoder 1 has a high-form accuracy surface (outer diameter FD of a flat surface) on the sensor-opposed surface more radially outward than a range of a diameter (d−2·r) determined by an inner diameter d of the cylindrical part 2A and a radius r of a corner between the cylindrical part 2A and the inward flange part 2B. An outer diameter MD of the annular plastic magnet 3 is positioned on the high-form accuracy surface.