Mould for eliminating fishhook flaws of tile-shaped permanent magnetic ferrite and manufacture method of mould

Abstract

The invention discloses a mould for eliminating fishhook flaws of tile-shaped permanent magnetic ferrite and a manufacture method of the mould. A tile-shaped grinding tool comprises a mould body, wherein a non magnet conductible layer is arranged on the surface of a lower mould of the mould body and comprises an inner arc surface, platforms on two sides of the inner arc surface, and a transition region between the inner arc surface and the platforms, and the thickness ratio of the inner arc surface to the platforms to the transition region is 2:3:1. The manufacture method comprises the steps of: preparing a ferrite pre-sintered material; ball-milling and crushing by adopting a wet process until a required particle size is reached; manufacturing a forming mould; pressing (pumping water, magnetizing and pressing); sintering; grinding; and inspecting and subpackaging. The mould has the advantages of favorably reducing the leakage magnetic flux, increasing the effective magnetic flux of an inner arc, and facilitating the improvement of the material performance; moreover the mould is simple to manufacture, unique and convenient to operate.

Description

technical field [0001] The invention relates to a method for manufacturing a mechanical mold, in particular to a method for manufacturing a forming mold capable of eliminating fishhook cracks on both sides of a tile-shaped permanent magnet ferrite. Background technique [0002] Most of the high-performance permanent magnet ferrite tile-shaped magnets are used in motors such as starting, ignition, braking, and displacement in automobiles. The magnet is produced by using permanent magnet ferrite material in a large-tonnage press and a mold. To make the tile-shaped magnet produce high performance, it must be radially oriented during molding, that is, the magnetic field generated from the magnetizing coil passes through the mold. A loop is generated between the upper and lower dies. Align the material powder and press it at the same time. When the upper and lower molds of the mold are made of magnetically conductive materials, there are no obvious defects on the surface of the ...

AI Technical Summary

Problems solved by technology

When the crack is not serious, it generally does not affect the function of the motor, and domestic and foreign counterparts have handled it in this way. If the upper mold is made of non-magnetic material, or the lower mold is made of non-magnetic material, if the thickness of this part is increased, there will be no cracks. A thick layer of stainless steel is welded on the surface of the upper and lower molds, but these will affect the performance parameters of the magnet material and cause waste

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