CN103240416A - Method and mould for manufacturing NeFeB (Neodymium iron boron) radiation-orientated ring magnet - Google Patents

Abstract

The invention provides a method for manufacturing NdFeB radiation-oriented ring magnets and molds thereof, including a mold body made of non-magnetic steel, magnetically conductive side plates are respectively arranged on both sides of the mold body, and the A fan-shaped radial magnetic silicon steel sheet with a central angle of 90° is arranged between the magnetically conductive side plates inside the mold body. A tile-shaped mold cavity is arranged in the middle of the magnetically conductive silicon steel sheet, and the tile-shaped mold cavity is filled with NdFeB magnetic powder. The NdFeB multi-pole magnetic ring assembled in place of the conventional magnetic tiles of the present invention is applied to the rotor to make a motor, which greatly improves the comprehensive performance of the servo motor system.

Description

A method of manufacturing NdFeB radiation orientation ring magnet and its mold

technical field

The invention belongs to the field of NdFeB magnetic rings, in particular to a method for manufacturing NdFeB radiation orientation ring magnets and a mold thereof. ``

Background technique

With the continuous development of the national economy and low-carbon environmental protection economy, the requirements for automation in various fields of social development are also increasing, which makes the role of the servo motor system, which is characterized by precise control, more and more important in the process of social development. important. This type of system is widely used in machine tools, printing equipment, packaging equipment, textile equipment, rubber and plastics, electronic semiconductors, wind power and solar energy. At present, more than 50% of the servo motor products in these industries are mainly occupied by foreign brands5 represented by Japan, South Korea, Europe and the United States. The overall market share of domestic brands is small, and there is still a big gap in technology. In some high-end applications field, even decades behind. At present, domestic servo motor systems generally use NdFeB multi-pole magnetic rings assembled from magnetic tiles, and the magnetic steel and the body are connected with adhesives. Therefore, the strength and life of the adhesive severely limit the service life of the motor. When the permanent magnet is used as the rotor of the motor, this problem is particularly prominent due to the centrifugal force; secondly, because the thickness of the adhesive is difficult to control, it directly affects the gap between the stator and the rotor of the motor, which reduces the efficiency of the motor to a certain extent; In addition, due to the difference in the performance of each magnetic tile, it has a great impact on the performance indicators such as the smoothness of the motor's operation. In short, the method of splicing multiple magnetic tiles in permanent magnet motors will bring a series of unfavorable factors that are difficult to overcome. Similar problems also exist in other application fields such as magnetic suspension bearings.

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Contents of the invention

In order to solve the above technical problems, the present invention provides a method for manufacturing NdFeB radiation-oriented ring magnets and a mold thereof.

A mold for manufacturing NdFeB radiation orientation ring magnets is characterized in that it includes a mold body made of non-magnetic steel, magnetically conductive side plates are respectively arranged on both sides of the mold body, and inside the mold body A fan-shaped radial magnetic silicon steel sheet with a central angle of 90° is set between the magnetic side plates, and a tile-shaped mold cavity is arranged in the middle of the magnetic silicon steel sheet, and the tile-shaped mold cavity is filled with NdFeB magnetic powder.

The mold for manufacturing NdFeB radiation orientation ring magnet is characterized in that the four corners of the mold body are respectively provided with positioning holes for the upper mold.

The method for manufacturing NdFeB radiation oriented ring magnets by the mold includes the steps of batching, powder making, pressing, sintering, and machining, and is characterized in that orientation pressing and secondary molding are used in the pressing step, Orientation pressing is carried out first, using the mold to press four tiles with a 90-degree radial orientation. During orientation pressing, the magnetic field follows the pole head-magnetic side plate-magnetic silicon steel sheet-tile-shaped cavity filled neodymium iron Boron magnetic powder - magnetic silicon steel sheet - magnetic side plate - pole to form a closed-loop magnetic circuit, and then perform secondary molding, put four tiles into a circular rubber mold, put an iron cylinder into a vacuum bag and vacuum It is sealed and assembled into a radiant ring blank by isostatic pressing, and then the iron cylinder is taken out and put into the sintering furnace for sintering.

A method for manufacturing NdFeB radiation orientation ring magnets of the present invention provides a method for producing sintered and formed NdFeB multipolar magnetic rings, which can replace the NdFeB multipolar magnetic rings assembled by conventional magnetic tiles, It is applied to the rotor and made into a motor, which greatly improves the comprehensive performance of the servo motor system. The sintered and formed NdFeB multi-pole magnetic ring produced by this method has the following advantages compared with the current NdFeB multi-pole magnetic ring assembled by magnetic tiles:

First, in terms of production cost, the formed sintered NdFeB multipole magnetic ring has obvious cost advantages, because the assembled NdFeB multipolar magnetic ring is generally cut into tiles by square wire, and then processed Finishing such as internal grinding and external grinding. The waste ratio of cut scraps is relatively large, resulting in a waste of expensive rare earth resources. And the cost of wire cutting processing is also very high. The sintered NdFeB multi-pole magnetic ring blank formed at one time does not need wire cutting, but only needs internal and external grinding to complete the finishing process, which will not cause waste of wire cutting scraps.

The sintered NdFeB multi-pole magnetic ring formed by the second sintering is significantly different from the radiation uniformity of the tile ring. The sintered NdFeB multi-pole magnetic ring formed at one time is composed of four 90-degree uniform radiation magnetic tiles. It has a 360-degree radiation orientation, and there is no radiation crossing area and dead angle. The more assembled tiles, the closer to the effect of radiation magnetization. It is not a 360-degree radiation orientation in the actual sense. There are certain radiation crossing areas and blind spot

third. The sintered NdFeB multi-pole magnetic ring formed by sintering is significantly different from that of the tile ring. The magnetic flux distribution on the surface of the sintered NdFeB multi-pole magnetic ring formed at one time is approximately sinusoidal, and the maximum surface magnetism of the magnetic pole is higher than that of the tile ring. , while the magnetic flux distribution on the surface of the tile splicing ring is approximately trapezoidal wave, and the maximum surface magnetism of the magnetic pole is obviously lower than that of the sintered NdFeB multi-pole magnetic ring formed at one time.

Description of drawings

Fig. 1 is a mold schematic diagram of the present invention;

In the figure, 1—magnetic side plate; 2—non-magnetic steel; 3—tile-shaped mold cavity; 4—magnetic silicon steel sheet; 5—cobalt iron; 6—positioning hole of the upper mold.

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Detailed ways

As shown in Figure 1, the mold of the present invention has a special magnetic circuit design, and the magnetically conductive side plates of the mold are designed into a 90-degree radial magnetic circuit structure, and the magnetically conductive side plates on both sides of the mold are inlaid with magnetically conductive silicon steel sheets and made It is radiated at 90 degrees and cast with epoxy resin. The middle mold cavity is tile-shaped and filled with NdFeB magnetic powder. The two sides of the tile-shaped mold cavity are made of non-magnetic steel material, which will not be magnetized and will not block the magnetic force lines. , and contribute to the uniform distribution of radial magnetic field lines. When the forming press is oriented and pressed, the magnetic field follows the pole head—magnetic side plate—magnetic silicon steel sheet—the NdFeB magnetic powder filled in the middle tile-shaped cavity (the magnetic powder is oriented at 90 degrees to form a closed-loop magnetic circuit)— Magnetic silicon steel sheet-magnetic side plate-pole head forms a closed-loop magnetic circuit.

The preparation process of the annular magnet with radial magnetic orientation of the present invention includes batching, powder making, orientation pressing, sintering, and machining; wherein during orientation pressing, the magnetic field follows the pole head—magnetic side plate—magnetic conduction Silicon steel sheet—NdFeB magnetic powder filled in the middle tile-shaped cavity (the magnetic powder is radiated at 90 degrees to form a closed-loop magnetic circuit for orientation)—magnetic silicon steel sheet—magnetic side plate—pole head to form a closed-loop magnetic circuit. The specific implementation method is to combine the female mold of the mold with the male mold of the mold, fill the NdFeB magnetic powder in the middle of the tile-shaped mold cavity, and then put the tile-shaped upper mold on the top of the mold (four positioning holes play the role of guiding and positioning ) together put the mold into the middle of the pole head of the press, press the upper cylinder down, and then press in the orientation, then upper the cylinder, take out the mold, remove the upper mold, open the male and female molds, and take off the tile blanks that have been pressed. Repeat the above action to make four tiles. Using the method of secondary molding, four tiles are put into a circular rubber mold, and an iron cylinder is placed in the center of the circle, then put into a vacuum bag to vacuumize and seal, and assembled into a radiant ring blank after isostatic pressing. Then carry out surface grinding, external grinding, internal grinding and other finishing.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention are included in the protection scope of the present invention. Inside.

Claims (3)

1. A mold for manufacturing NdFeB radiation orientation ring magnets is characterized in that it includes a mold body made of non-magnetic steel, magnetically conductive side plates are respectively arranged on both sides of the mold body, and in the mold body A fan-shaped radial magnetic silicon steel sheet with a central angle of 90° is arranged between the magnetically conductive side plates inside the body. A tile-shaped mold cavity is arranged in the middle of the magnetically conductive silicon steel sheet, and the tile-shaped mold cavity is filled with NdFeB magnetic powder. 2. A mold for manufacturing NdFeB radiation-oriented ring magnets as claimed in claim 1, characterized in that the four corners of the mold body are respectively provided with positioning holes for the upper mold. 3. A method of using a mold to manufacture NdFeB radiation orientation ring magnets as claimed in claim 1, comprising the steps of batching, powder making, molding, sintering, and machining, characterized in that orientation is used in the step of molding In the method of pressing and secondary forming, first carry out orientation pressing, use the mold to press four tiles with a radial orientation of 90 degrees, and the magnetic field goes along the pole head-magnetic side plate-magnetic silicon steel sheet during orientation pressing — NdFeB magnetic powder filled in the tile-shaped mold cavity — Magnetic silicon steel sheet — Magnetic side plate — Pole head forms a closed-loop magnetic circuit, and then performs secondary molding, puts four tiles into a circular rubber mold, and puts them in The iron cylinder is put into a vacuum bag and vacuum-sealed, assembled into a radiation ring blank by isostatic pressing, and then the iron cylinder is taken out and put into a sintering furnace for sintering.

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