Device for producing annular or arcuate magnet

Abstract

A device capable of producing an annular magnet or arcuate magnet with excellent dimensional accuracy and magnet performance, of which the mass is not greatly scattered. The device for producing the annular magnet, for example, includes a preforming section for obtaining an annular preformed body from a compound of a mixture of an anisotropic magnet powder and a thermosetting resin, a magnetic field orienting and forming section for obtaining an annular intermediate formed body by subjecting the annular preformed body to orienting and pressure-forming, a main forming section for obtaining an annular magnet by further forming the annular intermediate formed body, and a work transferring section for transferring works. The preforming section is provided with mass measuring means for measuring the mass of the annular preformed body, and a first lower punch of the preforming section is so arranged as to vary the volume of an annular cavity by varying the position thereof, which is before the pressure-forming process with a servomotor based on the mass of preformed body, which has been measured with the mass measuring means.