| 摘要 |
PURPOSE:To enlarge difference of magnetic property between both face of a magnet and to improve steeply magnetic property of peripheral face thereof by a method wherein compression molding is performed by installing nonmagnet ic substance, which has convex curved face at forming space side on the surface of forming space side of a lower punch at contact face portion with usable powder loaded. CONSTITUTION:A forming space is formed by inserting to a square piller state lower punch 2, which consists of magnetic substance inside square piller state space section installed a die 1 made by nonmagnetic substance and has convex curved face, then usable power is loaded inside the said space. A square piller state upper punch 4, which has concave curved face, is abutted on the upper edge face of the die 1 and a nonmagnetic substance 3, whose upper face size is the same as the lower punch 2 and is flat at forming space side, also is concave lens shape with concave curved face at the lower punch side, is sticked to magnetic pole surface of the lower punch 2. In this forming device, after slurry state usable power is loaded to forming space in the die 1, an electromagnetic coil 5 is excited and then magnetic field is formed, thereafter compression molding is performed lowering the die 1 and the upper punch 4. |
