Neodymium-iron-boron cylindrical form permanent magnetic material with longitudinal through-hole molding method and special moulds

Abstract

The invention discloses a forming method of Nd-Fe-B cylindrical permanent magnetic material which is equipped with a vertical through hole; a metal internal lower mold (4) is combined with a metal external mold and half of the quantitative starch is poured into the combination; and then a first metal internal upper mold is inserted and a magnetic field forming press is used for obtaining the lower cylindrical permanent material; stripping; the first metal upper mold is taken out and a metal round rod (7) is put in the semi-circle hole of lower semi-cylindrical permanent magnetic material and the other half of the starch is poured in and then a second metal internal upper mold (2) is inserted to be formed on the magnetic field forming press; the metal round rod (7) is taken out after stripping and the Nd-Fe-B cylindrical permanent magnetic material (11); the special mold is characterized in that one metal internal lower mold (4) is matched with two metal internal upper mold. The invention reduces the waste of material and promotes the product yield; at the same time, the production efficiency is increased and the production cost is reduced.

Description

technical field [0001] The invention relates to a manufacturing method and special equipment for a NdFeB cylindrical permanent magnet material with a longitudinal through hole, in particular to a molding method and special equipment for a NdFeB cylindrical permanent magnet material with a longitudinal through hole. mold. Background technique [0002] The production of NdFeB cylindrical permanent magnet materials with longitudinal through holes has a history of several decades. In the prior art, the manufacturing method of NdFeB cylindrical permanent magnet materials with longitudinal through holes is generally as follows: raw material batching → Vacuum smelting into alloy ingots → crushing and grinding machine to make fine particles → airflow milling into powders of required fineness → forming is to press into a solid cylindrical shape in a magnetic field → vacuum packaging → storage in a vacuum container after isostatic pressing →Sintering in a vacuum sintering furnace→Sur...

AI Technical Summary

Problems solved by technology

[0007] 1. Because it is solid sintering, during the sintering process, on the one hand, the center of the solid product cannot be exposed to the high-temperature sintering environment; Long, high energy consumption; at the same time, when heated in a high-temperature sintering environment, the heat exchange surface area of ​​the material is relatively small, and the consistency of product shrinkage is poor, so the stability of product performance and product quality are not ideal

[0008] 2. Since the drilling machine must be used to drill longitudinally, all the chips are discarded, so the waste of raw materials is large; and because the NdFeB permanent magnet material is hard and broken, the product is easily missing corners under the action of strong external force when drilling Or rupture, and at the same time, the product is often scrapped because the drill bit is broken in the product, resulting in a low product yield; moreover, because the product needs to be clamped and removed on the drilling machine one by one during drilling, the processing time is long and the production Low efficiency and long product production cycle; in addition, because the drill bit is easily broken during drilling, the drilling cost is high, and the labor cost above is high, so the production cost is high

Obviously, the mold of the above-mentioned prior art can only be pressed out the solid NdFeB cylindrical permanent magnet material

Images