Flow channel device capable of extruding out a plurality of magnets once for extruding machine and preparation method using same

Abstract

The invention provides a flow channel device capable of extruding out a plurality of rare earth magnets once for an extruding machine, and a method for preparing the plurality of the rare earth magnets extruded out once by the extruding flow channel device. The flow channel device comprises a device main body (1), a core rod (2), a cooling pipe (3), a cooler (5), a main heat flow channel (6), a plurality of branched heat flow channels (7), temperature sensors (8) and (12), and a mixing material inlet (9). The flow channel device can efficiently obtain novel rare earth magnets which have even texture, uniform magnetic property, high dimension precision in the length direction and good corrosion resistance without conicity and needle eyes.

Description

technical field [0001] The invention relates to a channel device for extruding multiple pieces of rare earth magnets at one time for an extrusion molding machine, and a method for preparing multiple rare earth magnets at one time by using the extrusion channel device. Background technique [0002] One of the main application fields of permanent magnet materials is motors. In the structure of most micro motors, the permanent magnets are in the shape of rings or tiles. The gap between the permanent magnets and the rotor is very small, 0.10-0.15mm or even smaller. It is accumulated by permanent magnet tolerance, rotor tolerance, assembly tolerance, etc. The large tolerance of the magnet or the taper in the length direction will directly affect the change of the gap size, thereby affecting the strength and reasonable distribution of the gap magnetic field, causing the motor to run unstable, and there are many technical problems such as noise and vibration. Therefore, in additio...

AI Technical Summary

Problems solved by technology

Compression-molded bonded NdFeB magnets have the following disadvantages: limited in pressing height, for example, thin-walled (1mm) ring magnets are difficult to prepare when the height is greater than 10mm, the density of the magnet is not uniform, and the shape of the magnet has a certain Deformation, large taper after magnet forming, etc.; injection-molded bonded NdFeB magnets have lower magnetic properties than compression-molded ones

However, the production efficiency of extrusion molding is very low. Usually, a machine can only be equipped with one extrusion port. One of the ways to improve production efficiency is to extrude multiple pieces of magnets at a time.

[0005] Chinese Patent No. ZL96119267.4, the name of the invention is "Rare Earth Bonded Magnet and Rare Earth Bonded Magnet Composition", Chinese Patent No. ZL 961119416, the name of the invention is "Rare Earth Bonded Magnet and Rare Earth Magnet Composition", Both give the composition of extrusion bonded NdFeB and the general preparation method, but do not involve the preparation technical conditions of extruding multiple pieces of bonded NdFeB at one time

However, for a set of bonded NdFeB magnets with multiple pieces, its application requires high dimensional accuracy, consistent density, and no segregation of components, so one extrusion of multiple pieces of bonded NdFeB magnets and plastics Multi-piece extrusion techniques vary widely

In addition, since the magnetic powder in the magnet raw material contains more than 85% and only a small amount of binder (nylon, resin, etc.), the density difference between the magnetic powder and the binder is about 6 times, and the extrusion process may cause component segregation or uneven density. Therefore, The multi-piece bonded NdFeB magnet extrusion technology in one set of equipment is more stringent in the control of process parameters

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